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Wyszukujesz frazę "GOLD" wg kryterium: Temat


Tytuł:
Recycling of Gold From Waste Electrical and Electronic Equipment by Electrorefining of Copper
Autorzy:
Wędrychowicz, Maciej
Piotrowicz, Andrzej
Gabryelewicz, Izabela
Stryjski, Roman
Krupa, Patryk
Okoniewska, Oliwia
Besta, Petr
Samolejová, Andrea
Powiązania:
https://bibliotekanauki.pl/articles/2174924.pdf
Data publikacji:
2022
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
gold electro-refining
e-waste
gold recovery
Opis:
This article presents the methods of processing gold-plated pins from, among others, used computer equipment and discusses the research results on the recovered metal. Due to the relatively small structure of the pins and the fact that the gold layer is only a few microns thick, recovering gold from them constitutes a significant challenge. On the other hand, gold is a precious metal which enables the collective removal of other metals to obtain pure gold. The suggested method involves compacting the gold-plated pins into an anode form and carrying out the electro-refining process. Metals, such as copper, tin and iron, pass into the anode sludge from which they can be extracted or serve as a commercial intermediate sold to smelter plants. The anode sludge was melted in the flame of an oxy-acetylene torch in a graphite crucible by adding borax. As a result of the melting, several metallic precipitates were obtained. Then they were hot-incorporated into a sample with a diameter of 30 mm and a height of 12 mm. Eventually, a pure gold alloy sample was obtained, which contains Cu 40.69%, Sn 9.61% and Au 48.58%.
Źródło:
Rocznik Ochrona Środowiska; 2022, 24; 371--382
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of different methods on the enrichment of Konya Inlice epithermal gold ores
Autorzy:
Selçuk, Ayşe Nur Döğme
Güney, Ali
Powiązania:
https://bibliotekanauki.pl/articles/1449684.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
enrichment
falcon concentrator
gold flotation
gold recovery
Opis:
In this study, firstly, enrichment experiments were carried out on the epithermal gold ore belonging to the Konya-İnlice region containing 2.38 ppm Au-containing oxide type ore and 1.39 ppm Au-containing sulfur ore with using Falcon device as a gravity enrichment method. In these group experiments, the effects of parameters such as centrifugal force, bowl type effect, and a solid ration of feeding were investigated. As the second enrichment method, the conventional flotation technique was applied. In these enrichment experiments, appropriate grain size, flotation time, amount of reagent, and amount of depressant, and pH effect were investigated. The results of these tests showed that while a concentrate assaying 4.79 ppm Au content was obtained with 7% recovery with Falcon Concentrator, a concentrate with 8.37 ppm Au content with 36.37 % recovery was obtained with flotation tests. Thus, if the middlings were theoretically distributed, the final concentrate recovery increased to 78.10% recovery increases to 78.10%.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 1; 147-160
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cena złota jako determinanta kursów akcji kopalni złota
Autorzy:
Mamcarz, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/610014.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
gold price
gold mine stocks
leverage
gold beta
cena złota
akcje kopalni złota
dźwignia
beta złota
Opis:
The goal of the article is to assess the exposure of gold mine stock prices to changes of its price between 1997 and 2016, using the gold price leverage as a measure expressed with the gold Beta. To implement this goal, an exponential model was constructed, and descriptive analysis was also used. Studies have shown that in the whole period analyzed the gold price leverage effect did not occur except in 3 companies. However, after the analyzed period was divided into subperiods (bull and bear gold market), the leverage effect was reported except for 5 companies during the bull market period. Therefore, the length of the analyzed period significantly impacts the obtained results. They are crucial to investors choosing between physical gold regarded as safer in the long run, and mining stocks, in which case they expect not only the leverage effect but also other benefits.
Celem artykułu jest ocena ekspozycji kursów akcji kopalni złota na zmiany jego ceny w latach 1997–2016 przy zastosowaniu jako miary dźwigni ceny złota, wyrażonej betą złota. Dla realizacji tego celu zbudowano model potęgowy, posłużono się także analizą opisową. Badania wykazały, że w całym analizowanym okresie, oprócz 3 spółek, nie wystąpił efekt dźwigni ceny złota. Natomiast po podzieleniu analizowanego okresu na subokresy (hossy i bessy na rynku złota), z wyjątkiem 5 spółek w okresie hossy, stwierdzono efekt dźwigni. Długość okresu analizy ma zatem duży wpływ na otrzymane wyniki. Są one istotne dla inwestorów dokonujących wyboru między fizycznymi produktami złota, uważanymi za bezpieczniejsze w dłuższym okresie, a akcjami kopalni, w przypadku których oczekują oni nie tylko efektu dźwigni, ale i innych korzyści.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio H – Oeconomia; 2017, 51, 4
0459-9586
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio H – Oeconomia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of Potential Phytoaccumulator Plants from Tailings Area as a Gold Phytomining Agent
Autorzy:
Kurniawan, Riky
Hamim, -
Henny, Cynthia
Satya, Awalina
Powiązania:
https://bibliotekanauki.pl/articles/2025733.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
phytoaccumulator
gold phytomining
gold mine tailing
Typha angustifolia
Cyperus haspan
Opis:
Indonesia comprises a high diversity of plant species, some of which may have a potential role as metal phytoaccumulators including gold (Au), known as phytomining agents. Some local plants grown at the metal-contaminated sites can become potential phytoaccumulators due to their adaptation capability to the metal-polluted conditions. Phytomining is one of the eco-friendly methods usually used to extract lowgrade metal bio-ore from the environment and this method can be applied on gold tailing waste. This study aimed to find the hyperaccumulator plants selected from a gold mine area, which can be applied for a gold (Au) phytomining agent. The study was located in Aneka Tambang Inc. (PT. ANTAM-UBPE Pongkor), Bogor, West Java, Indonesia. A vegetation analysis was carried out using a transect experiment on the area around gold mine tailings dam, and the samples were collected for further analysis. Tailings were sampled for metal analysis, while the plant samples including the below-ground and above-ground part of biomass were separated, washed, and weighed for the biomass and metal analyses. The total concentration of gold in the plants and tailings was measured by using a graphite furnace atomic absorption spectrophotometer (GF-AAS). There were 17 plant species identified as gold accumulators collected from the gold mine tailing area, which were potential phytomining agents. The gold measurement showed that all plants species had the ability to absorb gold residues from the tailings dam, indicating that all the plants have a potential role as gold phytoaccumulators. Among the species, Typha angustifolia had the highest importance value index (IVI) followed by Cyperus haspan. The results showed that T. angustifolia and C. haspan were among the plants with the highest potential as Au phytoaccumulators to support the gold phytomining program for the gold mine tailing area.
Źródło:
Journal of Ecological Engineering; 2022, 23, 1; 169-181
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Odnawianie się rozsypisk złotonośnych przedpola Sudetów Wschodnich
Renewal of gold-bearing placers from the East Sudetic Foreland, Poland
Autorzy:
Wierchowiec, J.
Powiązania:
https://bibliotekanauki.pl/articles/2061638.pdf
Data publikacji:
2018
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
rozsypiska złotonośne
charakterystyka złota okruchowego
złoto autogeniczne
Sudety Wschodnie
gold placer deposits
gold characteristic
authigenic gold
East Sudetes
Opis:
W obrębie sekwencji okruchowych przedpola Sudetów Wschodnich wyróżniono w sumie pięć różnowiekowych poziomów złotonośnych związanych z preglacjalnymi „białymi” żwirami typu serii Gozdnicy, wodnolodowcowymi piaskami i żwirami plejstocenu oraz osadami holoceńskich tarasów Złotego Potoku i Białej Głuchołaskiej. Maksymalne zawartości Au (0,4 g/m3 osadu) notuje się w grubookruchowych żwirach kwarcowych, przestrzennie związanych z preglacjalną (eoplejstoceńską) doliną paleo-Białej Głuchołaskiej. Na powierzchni wyróżnionych dwóch podtypów złocin (ziarna blaszkowo-płytkowe, płaskie lub wtórnie zdeformowane oraz cementacyjno-grudkowe) rozpoznano i opisano nano- i mikrostruktury (morfotypy) Au oraz wewnętrzne tekstury (widoczne w przekroju ziaren), wskazujące na procesy tzw. odnawiania się rozsypisk złotonośnych. Są one wiązane z selektywnym rozpuszczaniem złota w warunkach hipergenicznych, jego wytrącaniem z roztworu i wtórną rekrystalizacją prowadzącą w rezultacie do formowania skupień złota autogenicznego. Rozpoznano dwa morfotypy złota autogenicznego: banieczkowate lub drobnorobaczkowe skupienia Au oraz krystaliczne skupienia i przerosty złota. Wspomniane morfotypy są bardzo dobrze zachowane i nie noszą oznak abrazji. Szczegółowa analiza SEM pokazuje, że pojedyncze banieczkowate nanocząsteczki z czasem zrastały się formując inkrustacje Au, a ostatecznie warstwę złota autogenicznego na powierzchni złociny pełniącej rolę swego rodzaju osadnika dla nowych nanocząstek. Występowanie banieczkowatych lub drobnorobaczkowych skupień Au w paragenezie z minerałami ilastymi oraz brak jakichkolwiek oznak abrazji tych skupień wskazują, że utworzyły się one in situ, to jest są pochodzenia autogenicznego. Nano- i mikroskupienia złota robaczkowo-pęcherzykowego zbudowane ze złota amorficznego mogą być wynikiem koagulacji koloidów lub ich adsorpcji przez minerały ilaste wypełniające kawerny na powierzchni złocin. Krystaliczne przerosty złota są prawdopodobnie efektem rekrystalizacji złota koloidalnego wytrącanego na powierzchni złocin po depozycji w rozsypisku.
Auriferous sequences in the East Sudetic Foreland include up to five gold-bearing horizons and are associated with the so-called preglacial “White Gravels”, Pleistocene and Holocene fluvial deposits overlying the Neogene sediments of the Poznań formation or Paleozoic metamorphic rocks. The significant placer potential for gold in the region lies in the preglacial (Eopleistocene) fluvial drainage system, primarily in paleo-channels of the Biała Głuchołaska River. The White Gravels, the richest gold-bearing deposits, contain up to 0.4 g/m3 Au near the base of the auriferous horizon. Two visibly distinct gold sub-types are identified based on their overall morphology: 1) flaky gold, flattened or reshaped by refolding; 2) craggy, irregular grains. All the grains are alloys of gold and silver, with Te and Se occurring as trace amounts. Two distinct gold sub-types of detrital gold display surface morphotypes and internal textures of Au and Ag dissolution indicative of supergene gold modification, as well as authigenic Au formation and aggregation resulting in the renewal of gold-bearing placers. The indicative morphotypes include nano- to microparticulate bud- or bubble-like gold, as well as overgrowths and aggregates of crystalline plate-like gold. They are well preserved and lacking any signs of physical damage. Stages of the gold particles growth have been observed during the nano- to microtextural investigations of gold grains, from the isolated semi-spherical nanoparticles, agglomerates, to irregularly shaped plates of gold. The presence of nano- to microphase gold embedded in the fine-grained assemblages of clayey masses and the lack of any signs of grain surface abrasion confirmed that bud- and babble-like Au, as well as complex aggregates of plate-like gold, must have formed in situ, i.e. are authigenic in origin. Chemical transfer may be related to both the Au precipitation from a colloidal solution as well as the adsorption by clay minerals and surface precipitation of Au on particles of mineral substrate.
Źródło:
Biuletyn Państwowego Instytutu Geologicznego; 2018, 472; 213--229
0867-6143
Pojawia się w:
Biuletyn Państwowego Instytutu Geologicznego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of functionalized graphene oxide coatings on gold
Autorzy:
Trzaskowski, M.
Ciach, T.
Powiązania:
https://bibliotekanauki.pl/articles/285667.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
gold
coatings
graphene oxide
Źródło:
Engineering of Biomaterials; 2016, 19, 138; 88
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Photochemical production of gold films on the surface of fabric materials
Autorzy:
Abdurazova, Perizat
Sataev, Malik
Kenzhibayeva, Gulmira
Koshkarbayeva, Shayzada
Amanbayeva, Kalamkas
Raiymbekov, Yerkebulan
Powiązania:
https://bibliotekanauki.pl/articles/779051.pdf
Data publikacji:
2020
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
gold
nanoparticle
antibacteria
fabric
Opis:
A technology for producing gold films on the surface of fabric materials has been developed, which provides for preliminary wetting of the fabric product with aqueous solutions of gold (III) chloride. In this case, a sorption layer of gold chloride is formed on the surface of fabric materials. Then, when drying these products under sunlight, physicochemical and photochemical processes occur, leading initially to the formation of monovalent gold chlorides, which, having semiconductor properties, provide the release of elemental gold. After washing of by-products on the surface of the material remains an ultra-thin film of gold, which has a sufficiently strong grip on the base. Since the proposed technology does not require special equipment it can be used to apply functional films of gold on various products of technical, household and medical purposes.
Źródło:
Polish Journal of Chemical Technology; 2020, 22, 4; 28-30
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Auriferous wastes from the aban doned arsenic and gold mine in Złoty Stok (Sudetes Mts., SW Poland)
Autorzy:
Wierchowiec, J.
Wojciechowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/2059193.pdf
Data publikacji:
2009
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Sudetes
Złoty Stok
wastes
auriferous tailings
gold grade
resources of gold
Opis:
The historical arsenic and gold-ore operation at the Złoty Stok mine generated around 1 500 000 tonnes of wastes. The gold-bearing post-flotation tailing dumps, waste slag heaps, mined rock and arsenic roasting spoils (cinders) from mining of metamorphogenic, hydro -thermal As-Au deposits have been examined to evaluate their gold grade. The waste material is dominated by calc-silicate skarn, dolomitic marbles, serpentinites and As-Au ore fragments. Sulfides are mainly loellingite, arsenopyrite and pyrrothite with some pyrite, chalcopyrite, sphalerite and galena. In oxidized material, sulfides are rare or absent. Over 1000 samples of post-flotation waste muds and three bulk samples of mined rock spoils were analyzed. Only tailings show high concentrations of Au (0.8–20.1 ppm) and As (1.0–2.6 wt.%). Anaverage contents of other metals (in ppm) are: Cu — 177.5; Pb — 212.2; Zn — 127.5; Ag — 0.38; Pt — 0.006; Pd — 0.001. Analytical results indicate that concentrations of these elements are very low along profiles, with no obvious relation ship between content and depth. Average gold content of 0.3 ppm in waste slags disqualifies this material as a source of gold. The re main ing re sources of gold in the flotation tailings and waste heaps are estimated at as high as 2370 kg. The main pollutant is As with contents exceeding 52 100 ppm in the mined rock spoils.
Źródło:
Geological Quarterly; 2009, 53, 2; 233-240
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Orogeniczne żyłowe złoża złota i ich rozsypiska a największe światowe gorączki złota w drugiej połowie XIX wieku w Ameryce i Australii
Orogenic lode gold deposits and placers and the world’s largest Gold Rushes in the second half of 19exp.th century in America and Australia
Autorzy:
Mikulski, S. Z.
Powiązania:
https://bibliotekanauki.pl/articles/2074655.pdf
Data publikacji:
2009
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
złoto
złoże okruchowe
gorączka złota
gold
placer
orogenic lode
gold rush
Opis:
The paper presents geological, ore-mineralogical and economic characteristics of the goldfields in the Western USA (California and Yukon) and Australia (Bendigo-Ballart and Kalgoorlie regions). Moreover, common geological features of these areas, which were the place of modern Gold Rushes from the second half of 19th c. to the beginning of 20th c. are also described. Thanks to discovery of gold, these inhabited areas became the land of promise for millions of people and gold production contributed to economy of the fast growing nations. The first period of Gold Rushes began in California (USA) and Bendigo-Ballart region in Victoria (Australia) in 1848 and 1851, respectively. Placer gold was discovered first in Cenozoic alluvial sediments and subsequently in auriferous quartz lodes, which were the source of detrital gold. The detrital sediments appeared extremely rich in gold nuggets. The biggest nuggets, ca. 65.2 and 24.5 kg in weight, have been found in Bendigo and California, respectively. Placer gold production during the Gold Rush in California from 1848 to 1864 is estimated at ca. 1300 Mg Au. Since 1850, prospectors begun to discover numerous gold-bearing quartz veins (Mother Lode system) along the Sierra Nevada in California. These auriferous lodes gave over 1100 Mg of gold. In Bendigo-Ballart goldfields about 480 Mg of gold was extracted from placers and 260 Mg goldfrom from auriferous quartz veins in the years 1851–1861. The second period of modern Gold Rushes took place again in America (Yukon) in 1896 and in the Western Australia (Kalgoorlie) in 1893. In Yukon, gold was mainly extracted from Cenozoic river’s gravels (> 311 Mg) and in Kargoorlie—mainly from auriferous quartz-carbonate lodes. Some of goldfields with auriferous lodes discovered in 19th c. are still in production. Best example is here the Kargoorlie deposit that became recently the 3rd largest world producer of gold (> 1600 Mg Au). Gold production from lodes in California, Bendigo-Ballart and Kalgoorlie is roughly estimated at > 4000 Mg. Gold-bearing lodes formed as results of migration of fluids of various origin and gold precipitation in the upper crust within post-collisional tectonic settings. These lodes belong to orogenic type of gold deposits hosted by greenstone schist belts in metamorphic terranes of various age. Primary gold is bound mostly by auriferous sulphides—arsenopyrite and pyrite and as native gold which infills fractures in quartz and breccias. In California, Yukon and Victoria, rich placers were formed in the Cenozoic during exhumation of metamorphic terranes hosting auriferous gold lodes.
Źródło:
Przegląd Geologiczny; 2009, 57, 12; 1048-1056
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charakterystyka występowania złota rodzimego w Małej Panwi w Luboszycach koło Opola
Characteristics of the native gold from Mała Panew River in Luboszyce near Opole
Autorzy:
Muszer, A.
Ćwiertnia, J.
Powiązania:
https://bibliotekanauki.pl/articles/170667.pdf
Data publikacji:
2018
Wydawca:
Poltegor-Instytut Instytut Górnictwa Odkrywkowego
Tematy:
złoto rodzime
ziarna złota
złoto w rzece Mała Panew
native gold
gold grains
gold in the Mała Panew river
Opis:
Zbadano możliwość zastosowania mobilnego koncentratora grawitacyjnego do poszukiwań złota w jednym z prawych dopływów rzeki Odry. W koncentratach powstałych w wyniku wzbogacania materiału aluwialnego, pochodzących z rzeki Mała Panew, stwierdzono występowanie złota rodzimego. Złoto charakteryzuje się jasną, żółtą barwą, bardzo drobną strukturą oraz jest idealnie obtoczone a jego płatki pozawijane są do wewnątrz ziarn. Średnica wielkości złocinek nie przekracza 0,125 mm, tylko nieliczne przekraczają 0,2 mm.
The possibilities to use the mobile gravity concentrator to search for gold in in the right tributaries of the Odra River were investigated. The concentrations formed as a result of the enrichment of alluvial material originating from the Mała Panew River revealed the occurrence of native gold. Gold is characterized by bright, yellow color, very fine structure and it is perfectly rounded. Most of the vellums are smaller than 0.125 mm in diameter, only a few exceed the range of 0.2 mm. Oxide minerals (magnetite, hematite, ilmenite, rutile, anatase, goethite, psilomelane, pyrolusite) zirconium and garnets were found in the concentrates from alluvial’s material. Rock-forming minerals are dominated by bright red and pink-red garnets, quartz and zircons. All garnets and zirconium crystals are characterized by very good curvature. The presence of gold in the Opole region is related to the Warta glaciation and the emergence of the Wroclaw-Bremen ice-marginal valley at the glacial forehead.
Źródło:
Górnictwo Odkrywkowe; 2018, 59, 3; 111-114
0043-2075
Pojawia się w:
Górnictwo Odkrywkowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Złoto antropogeniczne z rejonu Złotoryi (Pogórze Kaczawskie)
Anthropogenic gold from Złotoryja area (Kaczawa Foothills)
Autorzy:
Muszer, A.
Ćwiertnia, J.
Kania, M.
Powiązania:
https://bibliotekanauki.pl/articles/170640.pdf
Data publikacji:
2016
Wydawca:
Poltegor-Instytut Instytut Górnictwa Odkrywkowego
Tematy:
złoto rodzime
złoto antropogeniczne
kruszce
sferule Fe-Ti
złoża złota
native gold
anthropogenic gold
ores
Fe-Ti spherules
gold deposits
Opis:
Zbadano możliwość zastosowania mobilnego koncentratora grawitacyjnego do poszukiwań złota w okolicy Złotoryi. W koncentratach powstałych w wyniku wzbogacania materiału aluwialnego okolicznych strumieni stwierdzono występowanie minerałów tlenkowych uwolnionych, tj. magnetytu, hematytu, ilmenitu, rutylu, anatazu, kasyterytu, goethytu, psylomelanu, piroluzytu oraz kuprytu. Ponadto stwierdzono obecność monacytu, wolframitu, cyrkonu, schelitu, granatów. Spośród siarczków i siarkoaresenków występują ziarna pirytu, chalkopirytu, arsenopirytu, sfalerytu, galeny, markasytu, framboidów pirytowych oraz kowelinu. W materiale badawczym stwierdzono obecność minerałów rodzimych oraz metali i ich stopów. Są to złoto rodzime, złoto antropogeniczne, złoto srebrowe, srebro rodzime, ołów metaliczny, miedź metaliczna, krzemki Fe oraz liczne sferule o składzie Ti-V-Fe. Złoto antropogeniczne charakteryzuje się strukturą gąbczastą i zawiera śladowe ilości Fe, Ni oraz Hg.
Mobile gravity concentrator was used to search for gold near Złotoryja. Oxide minerals (magnetite, hematite, ilmenite, rutile, anatase, cassiterite, goethite, psilomelane, pyrolusite and cuprite) and monazite, wolframite, zirconium, scheelite, garnets were found in the concentrates from alluvial’s material. Additionally sulfides and arsenic sulfides (pyrite, chalcopyrite, arsenopyrite, sphalerite, galena, marcasite, framboidal pyrite and covellite) were also found in the concentrate. During the study, material revealed the presence of native minerals and metals as well as their alloys (native gold, anthropogenic gold, Ag-gold, native silver, metallic lead, copper metal, Fe-silicide and spherule Ti-V-Fe). Anthropogenic gold has a spongy structure and contains trace amounts of Fe, Ni, and Hg.
Źródło:
Górnictwo Odkrywkowe; 2016, 57, 4; 5-11
0043-2075
Pojawia się w:
Górnictwo Odkrywkowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ryzyko inwestycji i dźwignia ceny złota w sektorze kopalni złota
Investment risk and the gold price leverage in gold-mining industry
Autorzy:
Mamcarz, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/589597.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Dźwignia ceny złota
Inwestycje
Ryzyko
Złoto
Gold
Gold price leverage
Investment
Risk
Opis:
W porównaniu z inwestycjami w złoto, fizyczne akcje spółek szeroko rozumianego sektora kopalni złota (eksploratorzy oraz producenci: początkujący, juniorzy i seniorzy) dają inwestorom szansę osiągania wyższych stóp zwrotu, ale również narażają ich na znaczne ryzyko. Ponadto może wystąpić odpowiednio dodatni lub ujemny efekt dźwigni ceny złota. Celem artykułu jest ocena zależności między zmianami ceny złota i kursami akcji wymienionych spółek reprezentowanych przez indeksy branżowe, a także identyfikacja i pomiar wielkości ryzyka oraz efektu dźwigni. W ocenie wykorzystano podstawowe statystyki opisowe, wykresy graficzne oraz analizę opisową. Okres analizy obejmował lata 2011-2015. Analiza empiryczna wykazała, że rozwój kursu akcji badanych spółek podążał, ogólnie mówiąc, za zmianą ceny złota. Cena determinowała osiągane przez inwestorów stopy zwrotu i ryzyko inwestycji. Inwestycje w akcje spółek eksploracyjnych charakteryzowały się wyższą (ujemną) stopą zwrotu i wyższym ryzykiem w porównaniu z akcjami kopalni. Dźwignia występowała częściej w przypadku kopalni niż eksploratorów, jednak była wyższa dla tych ostatnich. Przeważały ujemne efekty dźwigni.
In comparison with investment in physical products of gold investing in shares of mining industry companies (explorers and producers: early, junior, senior) make it possible for investors to achieve higher rates of return, but they are also associated with higher risk. Moreover the positive or negative leverage effect may occur. The aim of the paper is to assess the relationship between the changes in gold price and stocks of mentioned companies represented by industry indices, also identifying and measuring risk and the level of leverage effect. The study relied on basic descriptive statistics, graphic charts and descriptive analysis. The analysis covered five-year-long period (from 2011 to 2015). Empirical analysis showed that development of stock prices of considered companies followed, in general, changes in gold price. The price determined the rates of return achieved by investors and the risk level. Investment in exploration companies was characterized by higher (negative) rate of return and higher risk in comparison with producers’ companies. The leverage effect was observed more often for producers than for explorers, however was greater for the latter. Negative effects of leverage were more common.
Źródło:
Studia Ekonomiczne; 2017, 325; 109-120
2083-8611
Pojawia się w:
Studia Ekonomiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charakterystyka złota Hg - nośnego z wybranych obszarów Dolnego Śląska
Characteristics of Hg- bearing gold from selected areas of Lower Silesia
Autorzy:
Kania, M.
Muszer, A.
Powiązania:
https://bibliotekanauki.pl/articles/171254.pdf
Data publikacji:
2017
Wydawca:
Poltegor-Instytut Instytut Górnictwa Odkrywkowego
Tematy:
złoto rodzime
złoto antropogeniczne
złoto rtęciowe
amalgamacja
aluwium
Przedgórze Kaczawskie
native gold
anthropogenic gold
Hg-bearing gold
amalgamation
alluvium
Kaczawskie Foothills
Opis:
Z aluwiów korytowych Przedgórza Kaczawskiego i obszarów sąsiednich pozyskano ziarna złota rtęciowego z domieszką Hg do 6,95 % wag. Obecność rtęci najczęściej związana jest z partiami złota o wyższych zawartościach Ag. Ziarna podzielić można na podstawie różnic teksturalnych i składu chemicznego na dwie grupy. Pierwszą stanowią złociny o teksturze gąbczastej rozwiniętej w całej objętości ziaren, o zawartości Hg nie przekraczającej < 2 % wag. Złoto tego typu stanowi produkt procesu amalgamacji i jako efekt działalności antropogenicznej może występować we wszystkich znanych wystąpieniach złota rozsypiskowego. Drugą stanowią złociny o bimodalnej budowie, złożone ze stopu Au-Ag o składzie fazy metastabilnej lub elektrum i czystego złota rodzimego. Faza złota rodzimego nie zawiera rtęci. Faza srebrowa ma zwartą teksturę, a koncentracja Hg sięga kilku % wag. Prawdopodobnym obszarem alimentacyjnym tego typu złota są wychodnie stref kontaktu czerwonego spągowca - cechsztynu.
Particles of mercurial gold with Hg content of max. 6,95 wt % have been found in the riverbeds of the Kaczawskie Foothils and adjacent areas. The presence of mercury is predominantly connected with the parts of gold with higher concentration of silver. Due to structural and chemical differences two types of mercurial gold can be distinguished. The first one comprises gold particles with spongy structure developed in the whole volume of grains, in which the Hg concentration doesn’t exceed 2 wt %. The gold of this type represents the product of the amalgamation process and, as an effect of anthropogenic activity, can occur in the whole known placer gold deposits. The second one comprises gold particles of bimodal structure, made of Au-Ag alloy of unstable or electrum phase and phase of pure gold. The phase of pure gold doesn’t contain Hg. The phase of Ag-bearing gold has a dense structure with a Hg concentration of a few wt %. The outcrops of the contact zones between Rotliegend and Zechstein are the most probable sources of this type of gold.
Źródło:
Górnictwo Odkrywkowe; 2017, 58, 5; 11-21
0043-2075
Pojawia się w:
Górnictwo Odkrywkowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rola państwa w zagospodarowaniu niektórych surowców - wybrane przykłady
Role of the state in mineral commodities management-case studies
Autorzy:
Solecki, A.
Powiązania:
https://bibliotekanauki.pl/articles/170838.pdf
Data publikacji:
2018
Wydawca:
Poltegor-Instytut Instytut Górnictwa Odkrywkowego
Tematy:
złoto
guano
bursztyn
gold
amber
Opis:
Przedstawiono historyczne przykłady rozwiązań organizacyjno-prawnych związanych z eksploatacją surowców mineralnych. Wybrane przykłady obejmują złoto, guano i bursztyn i ilustrują problemy prawno-społeczne związane zarówno z występowaniem surowców poza obszarem suwerenności danego państwa jak i problemy związane z trudną do udokumentowania zasobów formą występowania złóż. Opisane rozwiązania obejmują zarówno pełną liberalizację poszukiwań i wydobycia małych złóż okruchowych (złoto; Rosja, USA) jak i militarne i polityczne wsparcie państwa przy akwizycji obszarów perspektywicznych (guano; USA). Szczególną uwagę poświęcono bursztynowi dla którego zaproponowano rozważenie możliwości liberalizacji podobnej do stosowanej w przypadku małych złóż złota w Rosji, zarówno carskiej jak i posowieckiej.
Historical examples of organizational and legal solutions related to the exploitation of mineral resources are presented. Selected examples include gold, guano and amber and illustrate legal and social problems related to both the occurrence of raw materials outside the sovereignty of a given country, as well as problems related to the difficulties in evaluation of resources. The solutions described include both full liberalization of exploration and exploitation of small placer deposits (gold, Russia, USA) as well as military and political support of the state in the acquisition of prospective areas (guano, USA). Particular attention was paid to amber, for which it was proposed to consider the possibility of liberalization similar to that used for small gold deposits both in Tsarist and post-Soviet Russia.
Źródło:
Górnictwo Odkrywkowe; 2018, 59, 3; 10-14
0043-2075
Pojawia się w:
Górnictwo Odkrywkowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fast Neutron Activation Analysis of gold by inelastic scattering, 197Au(n,ngamma)197Aum, by means of Plasma Focus device
Autorzy:
Verri, G.
Mezzetti, F.
Da Re, A.
Rapezzi, L.
Gribkov, V.
Powiązania:
https://bibliotekanauki.pl/articles/146754.pdf
Data publikacji:
2000
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
activation
gold
neutron
plasma focus
Opis:
The application of a Fast Neutron Activation Analysis (FNAA) technique on samples of pure gold, irradiated by a plasma focus of 7 kJ, has been investigated. The reaction was the inelastic scattering of neutrons, 197Au(n,n'gamma)197Aum. To avoid problems connected with peculiar features of the neutron emission from this kind of source, a preliminary standardisation of the method has been carried out. The results obtained have a practical interest in view of possible applications to the technology of extraction of minerals.
Źródło:
Nukleonika; 2000, 45, 3; 189-191
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
INWESTYCJA W ZŁOTO – BEZPIECZNA PRZYSTAŃ, ZABEZPIECZENIE CZY ŹRÓDŁO DYWERSYFIKACJI DLA POLSKIEGO INWESTORA
Investment in gold - safe haven, hedge or source of diversification for Polish investor
Autorzy:
Potrykus, Marcin
Powiązania:
https://bibliotekanauki.pl/articles/950639.pdf
Data publikacji:
2015
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
safe haven
gold
investing
diversification
Opis:
The article describes the concept of the hedge, diversifier and safe haven investments. The main goal of this study is to examine whether there are links between the rates of return achieved on the Warsaw Stock Exchange (WSE) and rates of return on investments in gold. The author tested following hypothesis: the return on investment in gold acts as a hedge investment in the long term in relation to investments in the WSE main index, and at a time when investment in the WSE main index recorded a negative rate of return, investment in gold is a safe haven investment. To verify the hypothesis the author uses correlation coefficients and his own measure. The main conclusion from the research is that investing in gold acts as a safe haven investment for the investor which invests on the WSE.
Źródło:
Financial Sciences. Nauki o Finansach; 2015, 3(24); 193-207
2080-5993
2449-9811
Pojawia się w:
Financial Sciences. Nauki o Finansach
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of leaching kinetics modelling to a gold cyanide leach plant by using real plant data
Autorzy:
Sayiner, B.
Powiązania:
https://bibliotekanauki.pl/articles/109738.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
gold
cyanide
leach
kinetics
model
Opis:
Gold cyanide leach kinetics modeling was applied to the Bergama Ovacik gold cyanide leach plant in Turkey by processing the real plant data without need of any laboratory work. For this aim, solid ore samples were taken from each leaching tanks and analysed for gold contents as Au ppm while plant variables such as solid % concentrations in each tank, feed rate of plant as megagrams per hour (Mg/h), slurry flow rate as m3/h and the slurry residence times in each tank calculated and noted for modelling study. Five sampling work performed at plant at different times. Each sampling data were modelled seperately by the Anglo-American Research Laboratories (AARL) leach kinetics model to obtain five seperate model parameters and regression coefficient (R2) values. Then, total five sampling data were all together modelled to obtain just one model equation and R2 value to represent the plant generally. All R2 values were above 0.90 indicating that the AARL gold leaching kinetics model fits well on real plant leaching conditions. By using the model parameters, the residual gold contents in each tank were predicted for different possible ore feed rate tonnages such as 80, 90, 100, 110 and 120 megagrams per hour. Thus, leaching recoveries for any ore feed rate would be estimated for possible tonnage increases in the future.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 1; 109-114
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Controllable preparation of highly active horseradish peroxidase-gold nanoparticle bionanoconjugate
Autorzy:
Zhang, P.
Liu, Ch.
Song, S.
Peng, Ch.
Powiązania:
https://bibliotekanauki.pl/articles/778931.pdf
Data publikacji:
2012
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
horseradish peroxidase
gold nanoparticles
bionanoconjugate
Opis:
A novel method of immobilizing horse radish peroxidase enzyme (HRP) onto the surface of gold nanoparticles (GNPs) was developed. As a result, a high-activity bionanoconjugates was obtained through utilizing the biotin-streptavidin (SA) system. The HRP-SA-GNP bionanoconjugate with high activity was conveniently prepared through the biotin- avidin system. Compared with the HRP-GNP bioconjugate prepared through the traditional electrostatic absorption method, the enzyme activity per GNPs of this new bionanoconjugate was enhanced by 10 times. Moreover, the enzyme activity of this bionanoconjugate was controllable. The above method of bionanoconjugation preparation has promising applications In the fi elds including preparing highly active bio-nanoprobe and immobilized enzyme.
Źródło:
Polish Journal of Chemical Technology; 2012, 14, 4; 57-60
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification and Correlation Test of Mercury Levels in Community Urine at Traditional Gold Processing Locations
Autorzy:
Lensoni
Adlim, M.
Kamil, Hajjul
Karma, Taufiq
Suhendrayatna
Powiązania:
https://bibliotekanauki.pl/articles/24201654.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
urine
society
gold
mercury
mine
Opis:
Gold processing activities in Paya Seumantok Village, Krueng Sabee District, Aceh Jaya Regency, are known to utilize traditional mercury, posing a health threat to the workers and the local community. This study aims to identify local people’s urinary mercury levels near the gold processing plant in Paya Seumantok Village and to see the relationship between mercury levels and disease symptoms exhibited by the local people. To this end, ninety-one participants were recruited from a total member of a population of 928 people, determined using Slovin’s formula. The urine sample was collected using a purposive sampling technique following the procedure set by the regulation of the Minister of Health no. 43/2013. AAS Instrument was used to analyze the urinary mercury level. Sixteen out of 91 urine samples exhibited no mercury, while the rest, 75 samples, were found to contain mercury. The average urinary mercury level among local people near the site was 8.392 μg/L (SD: 6.721 g/L), while the minimum and maximum urinary mercury levels in this study were 0.19 μg/L and. 28.31 μg/L, respectively. Thirty-six samples were found to have mercury levels exceeding the acceptable threshold (7 μg/L), while thirty-nine samples had urinary mercury levels below the threshold. This study concluded that there is no relationship between urinary mercury levels and symptoms of acute and chronic diseases experienced local community and workers at the gold processing site in Paya Seumantok Village, Krueng Sabee District, Aceh Jaya Regency (p > 0.05).
Źródło:
Journal of Ecological Engineering; 2023, 24, 3; 357--365
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dalej niż daleko. Znaczenie geograficznego usytuowania Australii we wspomnieniach Seweryna Korzelińskiego i Bolesława Dolańskiego
Far, far away... Australian geographical location in Seweryn Korzeliński’s and Bolesław Dolański’s memoirs
Autorzy:
Bąk, Magdalena
Powiązania:
https://bibliotekanauki.pl/articles/510931.pdf
Data publikacji:
2016
Wydawca:
Wydawnictwo Uniwersytetu Śląskiego
Tematy:
Australia
journey
gold rush
antipodes
Opis:
The aim of the article is to analyse the way in which Seweryn Korzeliński and Bolesław Dolański describe the geographical location of Australia (the distance that separates it from Europe). In many reports from Australia and literary texts describing the continent, written either before or after Korzeliński’s and Dolański’s memoirs, the distance that separates Australia from Europe is considered the main characteristic feature that determines the way in which other Australian phenomena are regarded. The article discusses the interesting way in which the two authors present Australian geographical location and the purpose this literary interpretation serves in their memoirs.
Źródło:
Postscriptum Polonistyczne; 2016, 1(17); 11-22
1898-1593
2353-9844
Pojawia się w:
Postscriptum Polonistyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inwestycje w złoto jako zabezpieczenie przed inflacją w Polsce
Autorzy:
Kasprzak-Czelej, Anna Barbara
Powiązania:
https://bibliotekanauki.pl/articles/610998.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
gold
inflation
hedging
złoto
inflacja
Opis:
This study analyzes the question whether direct gold investments provide the ability of hedging against inflation in Poland. Using monthly data on the price of gold and selected inflation measures during the period January 2007 – April 2015 the cointegration tests and the cross-correlations were conducted. The results suggest that investments in gold has not served as a hedge against fluctuations in the internal purchasing power of the Polish zloty.
W niniejszym artykule, celem ustalenia, czy bezpośrednie inwestycje w złoto mogą zabezpieczyć przed spadkiem wewnętrznej siły nabywczej PLN, przeprowadzono z wykorzystaniem miesięcznych danych z okresu styczeń 2007 r. – kwiecień 2015 r. analizę kointegracji oraz korelacji z opóźnieniami. Uzyskane wyniki sugerują brak możliwości zabezpieczania się przed inflacją w Polsce przez fizyczne nabycie złota. 
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio H – Oeconomia; 2015, 49, 4
0459-9586
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio H – Oeconomia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Akcje kopalni złota jako instrument inwestowania kapitału
Autorzy:
Mamcarz, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/611170.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
explorers
gold mines
gold-mining stocks
index of gold mining-stocks
investment risk
leverage of gold price
spółki eksploracyjne, kopalnie złota, akcje kopalni złota, indeks akcji kopalni złota, ryzyko inwestycyjne, dźwignia ceny złota
Opis:
In the gold-mining stocks market there is a great number of companies, from explorers to gold mines. The stocks of these companies give investors ample opportunities to invest capital, but they are also associated with high risk. This stems from the specificity of mining industries and the relationship between prices of gold-mining stocks and gold prices in world markets. This relationship is expressed by the gold price leverage effect. On the basis of the analysis of empirical data it should be said that this effect occurred although this did not apply to the whole period investigated.
Artykuł nie zawiera abstraktu w języku polskim
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio H – Oeconomia; 2014, 48, 1
0459-9586
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio H – Oeconomia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Retention force assessment in conical crowns in different material combinations
Autorzy:
Pietruski, J. K.
Sajewicz, E.
Sudnik, J.
Pietruska, M. D.
Powiązania:
https://bibliotekanauki.pl/articles/307153.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
retention force
conical crowns
gold casting alloy
gold electroforming alloy
korona zęba
retencja
implant
odlew
Opis:
The puprose of this study was to evaluate retention force of conical double crowns in two material connections: gold casting alloy/gold casting alloy and gold casting alloy/gold electroforming alloy. 12 crown pairs of both material connections with the cone angles of 2°, 4° and 6° were made. Experiment of 10.000 in-and-out cycles was performed using a new device which allows the retentive force to be measured in continuous way without necessity of moving the samples to another device. It has been found that the higher the retentive force values, the lower the cone angle. Dispersion of the retention value was similar in both groups, but when cone angle was 2° or 4°, stability of retention force with the passage of time was higher in combinations with electroformed copings. The optimum solution was the cast alloy/cast alloy connection but only with cone angle 6°. However, retentive values seem to be too low to achieve proper retention of dentures.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 1; 35-42
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of hydrogen peroxide and lead(II) nitrate on gold cyanide leaching of Malaysian mesothermal deposit gold ore
Autorzy:
Baharun, Norlia
Ling, Ong Pek
Ardani, Mohammad Rezaei
Ariffin, Kamar Shah
Powiązania:
https://bibliotekanauki.pl/articles/1845218.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
gold cyanidation
mesothermal lode gold
statistical analysis
design of experiment
Van’t Hoff differential method
Opis:
The gold extraction from Malaysian mesothermal lode gold ore through the cyanidation method was performed. The effect of hydrogen peroxide (H2O2) and lead nitrate Pb(NO3)2 were investigated on the percentage of gold recovery. The statistical analysis method using a response surface design-central composite design was applied to find the optimum condition for gold extraction. The studied parameters were NaCN concentration (300-500 ppm), H2O2 concentration (205-410 ppm), and Pb(NO3)2 concentration (50-150 ppm). It was found that increasing the amount of NaCN and H2O2 as well as decreasing the amount of Pb(NO3)2 in the studied range, increased the gold recovery. The analysis of variance suggested the linear model for the gold extraction with the optimum condition at 467.3 ppm NaCN, 94.96 ppm Pb(NO3)2, and 340 ppm H2O2. The gold extracted from the ore at the optimum condition was 88.97% as compared to 62.02% from conventional cyanidation. The characterization study of the gold ore indicated that the finely gold particles interlocked in the aluminosilicate phase (grain size of ~10.0 μm). The Van’t Hoff differential method justified that the cyanidation was of second order with a specific reaction rate of 0.0501/hour.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 5; 905-918
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza korelacji notowań kursu cen złota i kryptowaluty bitcoin nazywanej „cyfrowym złotem”
Correlation analysis of the price quotations of gold and the bitcoin cryptocurrency called "digital gold"
Autorzy:
Błoński, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/28407258.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
Bitcoin
digital gold
21st-century gold
cryptocurrencies
bitcoin
cyfrowe złoto
złoto XXI w.
kryptowaluty
Opis:
W artykule dokonano analizy zależności kursu notowań cyfrowej waluty bitcoin z notowaniami cen złota w latach 2018–2022. Przeanalizowano także zależności notowań kursu BTC z indeksami akcyjnymi Stanów Zjednoczonych (S&P 500) i Polski (WIG) oraz indeksem towarowym CRB. W badaniu wykorzystano liniową korelację Pearsona. Badanie przeprowadzono dla kilku różnych okresów. Pierwszy okres obejmował lata 2018‒2022, drugi lata 2020–2022, a trzeci ostatni rok, tj. 2022. Badanie przeprowadzono również dla dwóch okresów o zwiększonej niepewności rynkowej. Pierwszy to czas załamania się rynków spowodowany wybuchem pandemii COVID-19 i dużej zmienności na rynku od 1.03.2020 do 30.04.2020. Drugi to początek wojny w Ukrainie obejmujący notowania od 24.02.2022 do 24.04.2022. Przeprowadzone badania wskazują, że kryptowaluta Bitcoin w większym stopniu koreluje z indeksami giełdowymi niż z kursem notowań cen złota. W ostatnim badanym okresie, tj. na początku wojny w Ukrainie, można było zaobserwować nawet ujemną korelację kursów notowań cyfrowej waluty Bitcoin i cen złota.
The paper analyses the relationship between the Bitcoin digital currency quotation and the gold price quotation in 2018–2022. The relationship between the BTC exchange rate quotation and the stock indices of the United States (S&P 500) and Polish (WIG) and the CRB commodity index was also analysed. The study used a linear Pearson correlation. The study was conducted for several different periods. The first period covered 2017–2022, the second period was 2020–2022, and the third – last year, i.e. 2022. The study was also conducted for two periods of increased market uncertainty. The first is the time of the collapse of the markets caused by the outbreak of the COVID-19 pandemic and high market volatility from March 1, 2020, to April 30, 2020. The second is the beginning of the war in Ukraine, covering quotations from February 24, 2022, to April 24, 2022. Research indicates that the Bitcoin cryptocurrency correlates to a greater extent with stock exchange indices than with the price quotation rate of gold. In the last period studied, i.e., at the beginning of the war in Ukraine, it was even possible to observe a negative correlation between the price quotations of the digital currency Bitcoin and gold prices.
Źródło:
Ekonomia Międzynarodowa; 2022, 39; 143-153
2082-4440
2300-6005
Pojawia się w:
Ekonomia Międzynarodowa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recovery of gold (III), palladium (II) and platinum (IV) ions from chloride solutions on the solvent impregnated resin (SIR) — Dowex Optipore L493
Autorzy:
Wójcik, G.
Hubicki, Z.
Górska, M.
Powiązania:
https://bibliotekanauki.pl/articles/115536.pdf
Data publikacji:
2011
Wydawca:
Fundacja na Rzecz Młodych Naukowców
Tematy:
gold
platinum
palladium
solvent impregnated resins
Opis:
The method described in this paper using Dowex Optipore L493 for removal of gold (III), palladium (II), and platinum (IV) ions from hydrochloric solutions is found effective for separation of gold, palladium and platinum. There were carried out laboratory studies of selective removal of platinum (IV), gold (III) and palladium (II) microquantities from 0.1–6 M hydrochloric on the solvent impregnated highly cross-linked styrenic polymer, Dowex Optipore L493 using Cyanex 301. In these experiments the recovery factors % R of gold (III), palladium (II) and platinum (IV) depending on phases contact time were obtained. The gold, palladium and platinum concentrations were determined by the AAS method.
Źródło:
Challenges of Modern Technology; 2011, 2, 3; 38-40
2082-2863
2353-4419
Pojawia się w:
Challenges of Modern Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania mineralogiczno-geochemiczne złota z Podlesia-Gęstwiny w Górach Złotych, Dolny Śląsk, Polska
Mineralogical and geocehmical investigation of gold from Podlesie - Gęstwina in Golden Mountains, Lower Silesia, Poland
Autorzy:
Pawlikowski, M.
Czarnecka, K.
Powiązania:
https://bibliotekanauki.pl/articles/344070.pdf
Data publikacji:
2018
Wydawca:
nakł. Maciej Pawlikowski
Tematy:
złoto
Góry Złote
gold
Golden Mountains
Opis:
Przeprowadzono badania mineralogiczne ziarn zlota wystepujących w piaskach i żwirach wPodleciu-Gęstwinie w Górach Złotych. W badaniach wykorzystano mikroskopie skaningową i spektroskopie (EDS). Stwierdzono wysoką czystośc złota i śladowe domieszki Mg, Pb. Ag i F. Wykonano także oznaczenia składu petrograficznego skał w których występuje badane złoto. Stwioerdono, że zbudowane są one głównie z ziarn amfibolitów, gnejsów i róznych odmian łupków metamorficznych.
Mineralogical investigation of small grains of gold present at sands and gravels of Podlesie-Gestwina (Golden Mountains- South Poland) were performed using SEM and EDS methods. Results document high concentration of gold and small admixture og Mg, Pb, Ag, and F. Petrographic compozition of sediments was determined too. The main component is represented by metamorphic rocks (amphiobolites, gnaisess and metamorphic shists.
Źródło:
Auxiliary Sciences in Archaeology, Preservation of Relics and Environmental Engineering; 2018, 25; 141-150
1689-6742
Pojawia się w:
Auxiliary Sciences in Archaeology, Preservation of Relics and Environmental Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Black Market – Financial Crimes Committed for Personal Purposes
Autorzy:
Miłosz, Jan
Powiązania:
https://bibliotekanauki.pl/articles/1390726.pdf
Data publikacji:
2017-02-07
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
black market
gold
currency
smuggle
speculation
Opis:
In socialist Poland, in the reality of centrally planned economy, average citizens experienced chronic deficits of basic commodities. Although the intensity of the problem varied, at no time could one say that the official market fully satisfied the demand for basic or luxurious goods sought by citizens. On the one hand, the market was steered manually, prices were set and kept on the same level for many years, and the volume of production and its cost was centrally planned, but on the other hand, salaries in national companies were raised, which resulted in unsatisfied demand for the goods that the official market lacked. How, then, did average citizens deal with these problems? How, by committing more or less serious financial crimes, did they become players in the black market game, the stake of which was satisfying their own needs? This article attempts at describing the situation in this specific market in various periods of socialist Poland. It also tries to demonstrate which products were the most desirable and most often sold in the black market. Most citizens of socialist Poland, knowing that their behavior is against the law, limited their participation in the black market to purchasing or selling the most urgently needed products.
Źródło:
Studia Historiae Oeconomicae; 2016, 34; 45-62
0081-6485
Pojawia się w:
Studia Historiae Oeconomicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microanalysis study of Al-Amar rock and leaching behavior of its tailings for recovery of gold and silver
Autorzy:
Mahmoud, M. H. H.
Awad, H. M.
Altalhi, T.
Powiązania:
https://bibliotekanauki.pl/articles/109620.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
gold
silver
tailings
mineralogy
extraction
thiosulfate
Opis:
Some Saudi gold ores, such as that at Al-Amar mine, suffer from low leaching efficiency using the toxic cyanidation process. Only about 60% of the gold and 26% of the silver in the feed ore can be extracted at 0.2% CN– after 24 h and the rest percentages of these metals remained in leaching residues (tailings). These tailings contained 1.1 ppm Au and 4.3 ppm Ag. Reprocessing of tailings serves both for economic and environmental reasons. A petrography analysis of the mineral constituents indicated that the rock samples consisted primarily of sphalerite, chalcopyrite, pyrite and galena in decreasing order of abundance. An electron probe microanalysis quantitatively showed that gold and silver were finely distributed in the grain boundaries and within sphalerite, chalcopyrite, pyrite, and quartz. The dissemination of gold and silver in these hard minerals may be the main reason for their low recovery by cyanidation. Open air roasting of the tailings can release amounts of the disseminated gold and silver which can be extracted during leaching with the harmless thiosulfate ion S2O32–. After studying the different parameters, we found that the maximum possible extraction of gold and silver from the tailings roasted for 2 h at 400°C reached about 50% at 0.2 M ammonium thiosulfate, 0.3 M ammonium hydroxide, solid–liquid ratio ½ for 24 h. These achievements represent a possible exploitation of the accumulated 1.65 million Mg tailing waste containing significant amounts of gold and silver valued at about $73 million.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 527-537
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thiosulfate-copper-ammonia leaching of pure gold and pressure oxidized concentrate
Autorzy:
Porvali, A.
Rintala, L.
Aromaa, J.
Kaartinen, T.
Forsen, O.
Lundstrom, M.
Powiązania:
https://bibliotekanauki.pl/articles/110672.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
gold leaching
thiosulfate
quartz crystal microbalance
Opis:
In this research cyanide-free leaching of pure gold and pressure oxidized refractory gold concentrate by thiosulfate-copper-ammonia solutions were examined. A quartz crystal microbalance (QCM) was used to study gold leaching as a factorial series where the best gold leaching rate (2.987 mg/(cm2∙h)) was achieved with a solution consisting of 0.2 M (NH4)2S2O3, 1.2 M NH3, 0.01 M CuSO4 and 0.4 M Na2SO4. Temperature had the greatest effect on the gold leaching rate. An increase in thiosulfate concentration (0.1–0.2 M) increased gold dissolution. The combined effect of temperature and ammonia concentration had a statistically significant effect on the gold leaching rate at 0.1 M M2S2O3. Combination of applied potential and NH3:S2O3 ratio had a statistically significant effect on the gold leaching rate at 0.2 M M2S2O3. An increase in applied potential decreased the gold dissolution rate at low ammonia concentrations but increased it at high concentrations. A pressure oxidized gold concentrate was leached for 6 hours in the batch reactor leaching experiments. The effect of rotative velocity (1.26–1.56 m/s) and slurry density (10–30 wt%) was investigated at the following leaching parameters: 0.2 M Na2S2O3, 0.6 M NH3, 0.01 M CuSO4, 0.4 M Na2SO4. Lower slurry density (10 wt%) resulted in a higher Au leaching efficiency. An increase in the rotation rate did not have an effect on the final Au leaching recovery. The best Au leaching efficiency (89%) was achieved with 590 rpm mixing, 1.56 m/s rotative velocity and 10 wt% slurry density.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1079-1091
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preg-robbing of gold in chloride-bromide solution
Autorzy:
Ahtiainen, R.
Lundstrom, M.
Powiązania:
https://bibliotekanauki.pl/articles/110931.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
gold
leaching
pre-robbing
hydrometallurgy
carbon
Opis:
One of the major issue in gold chloride leaching is a tendency of gold to either precipitate or adsorb on a carbonaceous matter in an ore, i.e. preg-robbing. This paper discusses issues related to a preg-robbing phenomenon in gold hydrometallurgy, specifically in gold chloride-bromide leaching. This phenomenon has been observed in the 1800s to decrease gold recovery during gold chlorination as well as the state-of-art of gold cyanidation processes. The experiments were conducted in order to study the preg-robbing phenomenon in chloride-bromide media. The tendency of preg-robbing was demonstrated by adding carbon in a non-preg-robbing ore. It was shown that the preg-robbing tendency in the chloride-bromide media was very strong. Addition of 0.01% w/w of carbon powder into the non-preg-robbing ore decreased gold recovery from 92 to 70% and addition 5% w/w of carbon decreased gold recovery to almost zero.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 244-251
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gold catalysts supported on zeolites
Katalizatory złotowe osadzone na zeolitach
Autorzy:
Walkowiak, Adrian
Powiązania:
https://bibliotekanauki.pl/articles/2057912.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
heterogeniczne katalizatory złotowe
nanocząstki złota
zeolity
metody modyfikacji zeolitów złotem
zastosowanie zeolitów modyfikowanych złotem
proces katalityczny
heterogeneous gold catalysts
gold nanoparticles
zeolites
methods of zeolites modification with gold
application of gold-modified zeolites
catalytic process
Opis:
Heterogeneous gold catalysis is a relatively young but dynamically developing field of chemistry. At the end of the 1980s, Masatake Haruta and Graham Hutchings provided experimental evidence of high activity of supported gold catalysts in CO oxidation and acetylene hydrochlorination. Thus, these two researchers challenged the prevailing chemists’ belief that gold is almost completely chemically inert and catalytically inactive. Since then, gold catalysis has been constantly in the centre of attention of a wide array of scientists from around the world. However, there are still many questions about the nature of catalysts containing this noble metal, which inspires in-depth research in this field. From among various potential supports for gold heterogeneous catalysts, zeolites have drawn much attention thanks to several unique properties of this group of materials, among which the most important are high thermal stability and the presence of a system of pores of strictly defined sizes. Zeolites have extremely large surface area, which is desirable to obtain high dispersion of the active phase. The article provides a concise overview of the methods of gold nanoparticles deposition on zeolitic supports and catalytic applications of such materials. The first chapter sheds light on the properties of bulk and nano-sized Au and depicts the background of gold catalysis development. In the following part, a brief description of zeolites and their properties is delivered. The third chapter is devoted entirely to the description of several preparation methods of zeolite-supported gold catalysts and their applications in different catalytic processes. The following post-synthetic methods of zeolite modification with gold are described: impregnation, ion exchange, deposition-reduction, chemical vapour deposition, and grafting. The most important advantages and disadvantages of each method are summarized. The article concludes with a résumé of literature reports concerning the use of zeolitesupported gold catalysts in various processes. Special attention was paid to selective oxidation of alcohols and biomass-derived chemicals (e.g. glucose).
Źródło:
Wiadomości Chemiczne; 2021, 75, 11-12; 1259--1293
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Is Gold as an Alternative Investment a Good Solution During Pandemic?
Autorzy:
Juras, Alicja
Powiązania:
https://bibliotekanauki.pl/articles/1878742.pdf
Data publikacji:
2021-09-30
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
alternative investments
gold
pandemic
safe havens
Opis:
The aim of the article: The crisis, both in the economic and financial markets, can lead to a sudden downturn and a loss of savings. For this reason, during a crisis, safe investments are essential to reduce risks and avoid losses. This year’s coronavirus pandemic has caused a lot of confusion in the financial and investment world as well.The pandemic led to turbulence in the financial market and made investors look for the so-called safe havens. In the literature, these havens often include alternative investments with a high demand for gold. This article aims to check the validity of using gold as an investment during a pandemic. Methodology: In the paper, in order to achieve the formulated aim, the following stages were carried out: critical analysis of the literature regarding the factors influencing investment decisions and the characteristics alternatives instruments. The last stage was based on statistical analysis using the Pearson correlation method. Gold prices were compared with quotations of two price indexes: WIG20 and S&P500. Results of the research: The conducted analysis shows that gold as an alternative investment is a good hedge in times of crisis, therefore, it is also the case during ongoing pandemic. Alternative assets fulfill a hedging function, minimizing the risk of losses. Moreover, thanks to a negative correlation with the market, they give a possibility to increase investors’ capital in times of crisis.
Źródło:
Finanse i Prawo Finansowe; 2021, 3, 31; 79-88
2391-6478
2353-5601
Pojawia się w:
Finanse i Prawo Finansowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of lead nitrate on cyanide leaching of gold and silver from turkish gold ores
Autorzy:
Sayiner, B.
Powiązania:
https://bibliotekanauki.pl/articles/109335.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
lead nitrate
gold
silver
cyanide leaching
Opis:
Effect of lead nitrate addition on cyanidation of Havran, Ovacık, Mastra LCu (low copper) and Mastra HCu (high copper) gold ores was investigated by laboratory tests at the Ovacik Gold Mine Metallurgy Laboratory. Leach tests were performed at optimum NaCN additions and pH values while different lead nitrate additions were applied. Ovacik cyanidation plant leaching time, 24 hours for the constant 100 Mg/h ore feed rate was applied as optimal for all lead nitrate tests. Results showed the increase in gold and silver recoveries between 0.4-1.2% for gold and 3.9-11.6% for silver at the end of 24 hours leaching by the addition of lead nitrate as 0.1-0.5 kg/Mg. NaCN consumption decreased or did not change except for the Ovacik ore. In the case of the Ovacik ore it slightly increased.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 2; 507-514
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pressure oxidation of pyrite-arsenopyrite refractory gold concentrate
Autorzy:
Rusanen, L.
Aromaa, J.
Forsen, O.
Powiązania:
https://bibliotekanauki.pl/articles/110051.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
gold ore
hydrometallurgy
leaching
factorial design
Opis:
Refractory gold ores have poor gold recoveries with direct cyanide leaching. Typically the refractoriness is due to encapsulation of the gold particles inside the host mineral. To liberate gold for leaching the host mineral must be broken by mechanical or chemical means. The aim of this study was to study the effect of temperature, oxygen partial pressure and slurry density on pressure oxidation of pyrite-arsenopyrite gold concentrate. Batch oxidation tests in an autoclave were done using a factorial design. Different responses were measured and analysed to study effect of the three factors and oxidation kinet-ics. Generally, high slurry density required high temperature and oxygen partial pressure to reach com-plete oxidation. Oxidation kinetics at 225°C temperature, with 1050 kPa oxygen partial pressure and 15% slurry density was found to be fastest resulting in complete conversion of sulfides in 30 minutes. At 195°C, 700 kPa oxygen partial pressure and 10% slurry density, the oxidation kinetics for complete sul-fide conversion was about 60 minutes. Slurry densities above 10% had an adverse effect on the oxidation rate, when the temperature was below 225°C and oxygen partial pressure below 1050 kPa.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 1; 101-109
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gold leching from a Saudi ore by the nonpolluting thiosulfate process
Autorzy:
Mahmoud, M. H. H.
Awad, H. M.
Elhabib, O. A.
Powiązania:
https://bibliotekanauki.pl/articles/110379.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
gold
extraction
leaching
thiosulfate
Saudi ore
Opis:
In all working Saudi gold mines, ores are treated using the hazardous cyanidation process. Some Saudi gold ores, such as Al-Amar, is known to be refractory to cyanidation. In this work, we have examined the extraction of gold from Al-Amar gold ore by the much environmentally safer and efficient thiosulfate process. The run of mine (ROM) and carbon-in-leach (CIL) feed, that is obtained after separation of copper concentrate from ROM, samples were found to contain 6.5 and 3.6 ppm gold, respectively. The mineralogical microscopic investigations of ROM samples confirmed that fine gold specks were scattered and encapsulated inside sulfide or quartz base minerals. This could explain the expected reason of the difficult leaching of gold by cyanidation. The X-ray diffraction analysis showed that the CIL feed contained quartz, pyrite, sphalerite and chlorite minerals. After detailed leaching studies of CIL feed, almost 70% of gold could be extracted at 0.2 M ammonium thiosulfate and 0.3 M ammonium hydroxide after 24 h. Addition of copper(II) as <0.2 mM only slightly enhanced the gold leaching in the ammoniacal thiosulfate solution. Gold leaching drastically decreased as the concentration of copper(II) increased 0.2 mM due to the degradation of S2O3²¯.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 1; 59-72
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gold recovery from refractory gold concentrates by pressure oxidation pre-treatment and thiosulfate leaching
Autorzy:
Yu, Li
Li, Shimei
Liu, Quanjun
Deng, Jiushuai
Luo, Bin
Liang, Yuanqin
Zhao, Liuchuang
Lai, Hao
Powiązania:
https://bibliotekanauki.pl/articles/110871.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
gold
pressure oxidation
thiosulfate
leaching
RSM
Opis:
Naturally, refractory gold is enclosed by sulfide minerals such as pyrite and arsenopyrite and a higher content of organic carbon, which results in difficulty in the recovery of gold. In this study, the flotation gold concentrate before and after pressure oxidation (POX) was analyzed. The analysis of the Eh-pH diagram revealed that pyrite/arsenopyrite would be dissolved in higher oxidation potential. Results of SEM-EDS showed that the surface of minerals became very rough and structure of some particles was destroyed after POX. The XRD measurement showed that pyrite was oxidized to jarosite, and gangue minerals such as quartz and organic carbon were hardly changed. The process of thiosulfate leaching of gold was designed and optimized according to Miscellaneous implemented by Response Surface Methodology (RSM). Based on the results of ANOVA, leaching model was significant. In leaching, [S2O32-] played an important role and the interactions between [S2O32-] and [Cu2+] were significant. The effect of [HA] was relatively weak. Optimum process parameters of the initial reagent concentration were 505.00 mM for [S2O32-], 34.77 mM for [Cu2+], and 0.50 mM for [HA]. Under these conditions, the Au extraction value was about 86.21%, which was significantly higher than that obtained with leaching directly.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 2; 537-551
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved flotation of auriferous arsenopyrite by using a novel mixed collector in weakly alkaline pulp
Autorzy:
Wang, Xiaohui
Zhao, Kaile
Bo, Hui
Yan, Wu
Wang, Zhen
Gu, Guohua
Gao, Zhiyong
Powiązania:
https://bibliotekanauki.pl/articles/1845220.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
gold mine
arsenopyrite
mixed collector
flotation
Opis:
The purpose of using a mixed collector is to increase both flotation efficiency and selectivity. The mixed collector of potassium isopentyldithiocarbonate and N-dodecyl mercaptan exhibits high efficiency for the flotation of auriferous arsenopyrite, and the 2:1 mixing mass ratio of potassium isopentyldithiocarbonate and N-dodecyl mercaptan is preferred. Batch flotation tests indicate that a concentrate with the grade of 47.58 g/Mg Au and the recovery of 86.45% Au is achieved by using the mixed potassium isopentyldithiocarbonate/N-dodecyl mercaptan in weakly alkaline pulp. The collector mixture potassium isopentyldithiocarbonate + N-dodecyl mercaptan has greater adsorption density on the arsenopyrite surface than other conventional mixed collectors. The mixed potassium isopentyldithiocarbonate/N-dodecyl mercaptan can adsorb onto the arsenopyrite surface by intense chemisorptions, and the Sulfur-Iron chemical complexation is considered as the main adsorption mode. This is the reason why mixed potassium isopentyldithiocarbonate and N-dodecyl mercaptan collector can improve the flotation efficiency of auriferous sulfides.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 5; 996-1004
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of gold nanoparticles stabilized by chitosan using irradiation and sonication methods
Autorzy:
Czechowska-Biskup, Renata
Rokita, Bożena
Ulański, Piotr
Rosiak, Janusz M.
Powiązania:
https://bibliotekanauki.pl/articles/1035040.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
chitosan
gold nanoparticles
irradiation
sonication
stabilization
Opis:
Gold nanoparticles (AuNPs) were synthesized, in the absence of any reducing agent, using ionizing radiation or ultrasound in aqueous solutions of chloroauric acid (HAuCl4). Chitosan (average molecular weight 158 kDa, degree of deacetylation 90 %) was used as a stabilizing agent. Both techniques yielded AuNPs which were stable in solution at RT for at least 3 months after synthesis. UV-Vis spectroscopy was used to follow substrate decay, nanoparticles formation, size of the gold core and particles stability. Hydrodynamic radii and polydispersion of the chitozan-stabilized AuNPs (i.e. the whole core-shell nanoparticles) were determined by dynamic light scattering. Zeta potential measurements were performed to assess the surface charge and stability of the particles. Influence of synthesis parameters and presence of isopropanol on the formation and properties of the products have been described and reaction mechanisms have been discussed. Radiation and sonochemical methods are demonstrated to be very efficient, fast and easy-to-control methods of synthesizing gold nanoparticles, leaving behind no unreacted reducing agent or unwanted side products, while stabilization by chitosan provides AuNPs with excellent stability and long shelf life.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2015, 20; 18-33
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling the Gold Price in Turkish Free Market: Static Approach
Determinanty cen złota na wolnym rynku tureckim: podejście statystyczne
Autorzy:
Aras, Hakan
Powiązania:
https://bibliotekanauki.pl/articles/509514.pdf
Data publikacji:
2015
Wydawca:
Akademia Finansów i Biznesu Vistula
Tematy:
Turkish gold market
gold price determinants
multiple regression
turecki rynek złota
determinanty ceny złota
regresja wielokrotna
Opis:
In this paper, we analyse the determinants of gold prices in the Turkish free market using classic linear regression techniques. We modelled the gold price movement using two static models, a simple linear and a polynomial of degree three. We compared two models and concluded that third degree polynomial regression model fitted our data better and has greater explanatory power than simple linear model. Furthermore the most significant determinants of the gold price in Turkey are found to be gold mine production, US dollar exchange rate against Turkish lira and the consumer price index (TÜFE).
W artykule zanalizowano determinanty cen złota na wolnym rynku tureckim, z zastosowaniem technik klasycznej regresji liniowej. Dokonano modelowania ruchu cen złota, stosując dwa modele statyczne: prosty liniowy i wielomianowy trzeciego stopnia. Porównano dwa modele i wywnioskowano, że wielomianowy model regresji trzeciego stopnia lepiej pasował do naszych danych i ma większą moc wyjaśniającą niż prosty model liniowy. Co więcej, najistotniejszymi determinantami ceny złota w Turcji, jak się okazuje, jest produkcja kopalni złota, kurs wymiany dolara USA w stosunku do liry tureckiej i wskaźnik cen towarów i usług konsumpcyjnych (tur. TÜFE).
Źródło:
Zeszyty Naukowe Uczelni Vistula; 2015, 41(3)/2015 Stosunki Międzynarodowe; 103-121
2353-2688
Pojawia się w:
Zeszyty Naukowe Uczelni Vistula
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The early medieval village of Morawy: a grave field from the 11th century
Autorzy:
Danielewski, Marcin
Powiązania:
https://bibliotekanauki.pl/articles/1038169.pdf
Data publikacji:
2018-06-20
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
Morawy
grave field
captives
gold knob
Kuyavia
Opis:
This article deals with the issues of an 11th century grave field in Morawy village in Kuyavia. In the first Piast times, the area was an integral part of the dynasty’s dominion. Discovered in the 1930s, the grave field is of great importance from the point of view of considerations of ethnically foreign settlements in Poland.
Źródło:
Slavia Antiqua: rocznik poświęcony starożytnościom słowiańskim; 2017, 58; 115-136
0080-9993
Pojawia się w:
Slavia Antiqua: rocznik poświęcony starożytnościom słowiańskim
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Szmalec i „żydowskie złoto”
Szmalec and “Jewish gold”
Autorzy:
Molisak, Alina
Powiązania:
https://bibliotekanauki.pl/articles/1389598.pdf
Data publikacji:
2015-01-01
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
szmalcownictwo
“Jewish gold”
ethical guilt
historical discourse
Opis:
The article recalls two literary texts which signalled the facts denied or marginalized in Polish historical memory: a phenomenon of szmalcownictwo (blackmailing for money of Jews who were hiding) and the search for “Jewish gold”. The context for the study of both narrations is the contemporary historical discourse and its evolution that can be observed in the recent 10-20 years in the Polish public sphere.
Źródło:
Poznańskie Studia Polonistyczne. Seria Literacka; 2015, 25; 209-234
1233-8680
2450-4947
Pojawia się w:
Poznańskie Studia Polonistyczne. Seria Literacka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Physical separation route for printed circuit boards
Autorzy:
Burat, F.
Özer, M.
Powiązania:
https://bibliotekanauki.pl/articles/109975.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
physical methods
PCBs
environment
copper
gold
silver
Opis:
Recently, the consumption of electrical and electronic equipment (EEE) has increased with the advanced technology. A wide range of components made of metals, plastics and other substances are contained in EEE. Electronic waste (e-waste) is easily demounted and separated by manually methods; however, printed circuit board (PCB) which is one the most common components of e-waste need to be recycled with economic and environmental technologies. In this paper, employing physical separation methods to ground waste PCB, an eco-friendly, simple and environmental process for separation of valuable metals was designed and proposed. A heavy fraction with 40.8% Cu, 350 ppm Au and 475 ppm Ag content at recovery of 95.4% Cu, 77.7% Au and 65.1% Ag was obtained from a feed assaying 12% Cu, 130 ppm Au and 200 ppm Ag using shaking table separator. Cu grade was increased from 52.4% to 73.9% with the recovery over 92% by dry magnetic separator and copper alloys were separated from the waste matrix with 98% Cu recovery using electrostatic separator.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 554-566
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of the carbon in pulp (cip) process in gold cyanide leaching plants using the plant data
Autorzy:
Sayiner, B.
Powiązania:
https://bibliotekanauki.pl/articles/110084.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
modeling
cyanide leaching
activated carbon
adsorption
gold
Opis:
An improved method to model CIP plants by plant data is presented. The Turkish gold cyanide leaching CIP plants, Bergama Ovacik, Gumushane Mastra and Eskisehir Kaymaz were modeled by using gold concentrations of monthly carbon, solution and solids spot samples of adsorption tanks without a need of laboratory work. Five carbon adsorption models were used namely k-n, Nicol-Fleming, Dixon, Film Diffusion with Langmuir isotherm and Film Diffusion with Freundlich isotherm (Johns model). Several monthly obtained plant data were collected and modeled separately and model parameters as well as regression coefficient R2 values were found by non-linear regression. By comparing R2 values, the best fit model for the three CIP plants was determined as Film Diffusion with Langmuir Isotherm that R2 values were above 0.95. Thus, by using the best fit model, the Kaymaz plant was optimized for existing 49 Mg per hour ore feed tonnage and plant parameters were predicted according to planned feed tonnage increase to 120 Mg per hour.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 2; 841-852
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the effect of cyanidation after microwave roasting treatment on refractory gold/silver ores by characterization studies
Autorzy:
Yoğurtcuoğlu, Emine
Powiązania:
https://bibliotekanauki.pl/articles/2200333.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
pretreatment
microwave
cyanidation
characterization
refractory gold-silver
Opis:
In this article, the efficiency of microwave pretreatment, which is an environmentally friendly, low-energy consuming method for recovery from refractory gold-silver ores, was investigated. The ore sample belonged to the oxidized Bolkardağ deposit, which contains carbonate (calcite, dolomite, smithsonite, hydrozincite), silicate (quartz, hemimorphite), sulfate (beudantite, plumbo-jarosite), and iron oxy/oxyhydroxide (hematite, limonite) minerals. Sulfur/sulfate-bearing silver and gold minerals are found either together with gangue minerals or in inclusions. Approximately 90% gold and 48% silver recovery efficiencies were achieved with the cyanide process after microwave preroasting from the ore. Additionally, the ore, heat treatment product, and waste samples were investigated by characterization studies. In these studies, bond structures, mineral content, sample mass losses, element percentage content differences, and mineral percentage content differences in the samples were determined. As a result, the microwave pretreatment application in cyanidation was presented as a new research topic in terms of its application in the valuable refractory content of this type of oxide.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 1; art. no. 157487
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rapid Synthesis of Gold Nano-Particles Using Pulse Waved Potential in a Non-Aqueous Electrolyte
Autorzy:
Jang, J. G.
Lee, J.-O.
Lee, C. K.
Powiązania:
https://bibliotekanauki.pl/articles/352529.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gold
nanoparticle
nonaqueous electrolyte
pulse wave
catalyst
Opis:
Rapid synthesis of gold nanoparticles (AuNPs) by pulsed electrodeposition was investigated in the non-aqueous electrolyte, 1-ethyl-3-methyl-imidazoliumbis(trifluoro- methanesulfonyl)imide ([EMIM]TFSI) with gold trichloride (AuCl3). To aid the dissolution of AuCl3, 1-ethyl-3-methyl-imidazolium chloride ([EMIM]Cl) was used as a supporting electrolyte in [EMIM]TFSI. Cyclicvoltammetry experiments revealed a cathodic reaction corresponding to the reduction of gold at −0.4 V vs. Pt-QRE. To confirmthe electrodeposition process, potentiostatic electrodeposition of gold in the non-aqueous electrolyte was conducted at −0.4 V for 1 h at room temperature. To synthesize AuNPs, pulsed electrodeposition was conducted with controlled duty factor, pulse duration, and overpotential. The composition, particle-size distribution, and morphology of the AuNPs were confirmed by field-emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The electrodeposited AuNPs were uniformly distributed on the platinum electrode surface without any impurities arising from the non-aqueous electrolyte. The size distribution of AuNPs could be also controlled by the electrodeposition conditions.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 1389-1392
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Speciation of Mercury Contaminant in Public Gold Mine Tailing and its Stabilization Using Sulfur and Sulfide
Autorzy:
Trihadiningrum, Yulinah
Latif, Rezki Amalia
Rachman, Ranno Marlany
Powiązania:
https://bibliotekanauki.pl/articles/123133.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
mercury
gold mine
speciation
sulfide
sulfur
tailing
Opis:
The mercury-containing tailing waste from public gold mines in Indonesia is generally deposited on soil without treatment. This research aimed at determining the amount and composition of mercury species in the tailing, and testing the effect of sulfur and sulfide on mercury stabilization. Samples were collected from a tailing pile at different depths in a public gold mine in Kulon Progo, Indonesia. The samples were characterized according to the mercury concentrations and Toxicity Characteristic Leaching Procedure (TCLP) test. Mercury speciation was carried out using nitrogen gas flow into tailing samples, which were placed in three test tubes. The released mercuric species was entrapped in KCl and KmnO4 solutions. The mercury stabilization was carried out using sulfur and sodium sulfide. TCLP test was performed to the stabilization products. The mercury concentrations were measured using a mercury analyzer. The results showed that the mercury in the tailings were dominated by elemental Hgo, the concentrations of which in the tailing piles of 30, 60, and 90 cm depths were 74.7%, 71.6%, and 76.5% respectively. Those of ionic Hg2+ form were 25.3%, 28.4%, and 23.5%, respectively. Additions of sulfur powder and sodium sulfide solution produced stable black-colored mercury sulfide. When compared to sulfide, sulfur was more recommended for stabilizing mercury in the tailing waste.
Źródło:
Journal of Ecological Engineering; 2019, 20, 4; 29-34
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mineralogical study and enhanced gravity separation of gold-bearing mineral, South Eastern Desert, Egypt
Autorzy:
El-Sayed, Samah
Abdel-Khalek, N. A.
El-Shatoury, E. H.
Abdel-Motelib, A.
Hassan, M. S.
Abdel-Khalek, M.A.
Powiązania:
https://bibliotekanauki.pl/articles/1845207.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
gold
mineralogy
petrography
gravity separation
Falcon concentrator
Opis:
El-Hudi gold deposit, located in the South Eastern Desert of Egypt, represent large vein- type gold occurrence. The representative sample revealed the abundance of quartz as main constituent with minor amounts of mineral impurities. Gold was detectable (12 g/t) as determined using atomic absorption. The petrographic study revealed that the gold grains ranged from 10-40 μm. The grain boundaries of quartz are highly stained with iron minerals as hematite and limonite. Sericite mineral is common in discrete gold-bearing veins. Eroded pyrite was detected with high alteration leaving only cubic-shaped cavities behind. Different techniques for gravity separation were used to separate gold from the quartz mineral. After crushing and grinding of the sample, shaking table was used to upgrade the coarser fractions while Falcon concentrator was employed to upgrade the fine fraction. The best concentrate was obtained through grinding the whole sample to less than 0.2 mm, followed by cleaning steps. The gold content is increased from 12 to 145 g/t with total recovery of 78%.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 5; 839-848
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zasady przeliczania nakładów finansowych poniesionych w latach 1945–2010 przez Muzeum Pałacu w Wilanowie i jego poprzednika prawnego
Rules of counting financial costs incurred between 1945 and 2010 by The Palace Museum in Wilanów and its legal predecessor
Autorzy:
Kłusek, Mirosław
Powiązania:
https://bibliotekanauki.pl/articles/20311684.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
re-privatization
exchange rate
price of gold
Opis:
Between 1945 and 2010 the Palace Museum in Wilanów and its legal predecessor incurred particular financial costs which could be expressed in money (in circula-tion), in nominal values. The aim of this article is to express the costs according to unchanged price measures: the American dollar, gold and rye. The conducted research shows that the overall costs borne by The Palace Museum in Wilanów between 1945 and 2010 were 297 mln zł (Polish currency), after counting which included money exchange and denomination, or $124 mln (in USD). According to the average exchange rate in 2010, it gives the sum of 375 mln zł ($1 equals 3,02 zł). The costs measured in rye equalled 10.5 mln q (average price of rye in 2010 was 1 q = 42,12 zł). In the end, it gives the sum of 442 mln zł. As to world gold prices, the costs were 542,000 ounces of pure gold (in 2010 1 ounce of gold costs $1421,6). It gives $771 mln according to the average exchange rate in 2010 and 2329 mln zł ($1 = 3,02 zł). It can be a matter of discussion which one of these three measures shows the real value of the costs incurred since 1945. Fortunately, there is no question that a counting method which takes into consideration exchanged money and denomination ought not to be used in measuring nominal values.
Źródło:
Annales. Etyka w Życiu Gospodarczym; 2014, 17, 2; 97-111
1899-2226
2353-4869
Pojawia się w:
Annales. Etyka w Życiu Gospodarczym
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Podstawy społeczne i ekonomiczne powstania fenomenu złotnictwa wielbarskiego
The social and economic bases of the Wielbark Goldsmithing
Autorzy:
Gralak, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/15818112.pdf
Data publikacji:
2022-10-28
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
Wielbark culture
gold artefacts
exchange
amber
silver
Opis:
In the early first century AC, in the north of Poland (predominantly in Pomerania), the Wielbark culture developed with its group of specific features. Among them were numerous items of jewellery. It seems that their use was related to an extended social hierarchy and distant inter-regional trade contacts. The raw material used by the jewellers was most probably obtained from melted Roman coins. Amber exports were at the economic basis of obtaining the coins. The most frequent forms of trinkets:snake- and adder-inspired bracelets, reverse pear pendants, S-shaped buckles and others, are of entirely foreign origin. Their prototypes can be traced back to the pre-Roman areas along the Danube occupied by the Thracians and the Dacians or the La Tène culture population.
Źródło:
Slavia Antiqua: rocznik poświęcony starożytnościom słowiańskim; 2022, 63; 7-40
0080-9993
Pojawia się w:
Slavia Antiqua: rocznik poświęcony starożytnościom słowiańskim
Dostawca treści:
Biblioteka Nauki
Artykuł

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