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Tytuł:
Możliwości wykorzystania wybranych modeli bilansowych z projektu EUROHARP do oceny poziomu wymycia azotanów w warunkach polskich
The possibility of using some balance models included in EUROHARP project for the assessment of nitrate losses in Poland
Autorzy:
Żurek, A.
Powiązania:
https://bibliotekanauki.pl/articles/2063275.pdf
Data publikacji:
2008
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
azotany
poziom wymycia
modele bilansowe
nitrate
leaching
balance models
Opis:
Projekt EUROHARP (Towards European Harmonized Procedures for Quantification of Nutrient Losses from Diffuse Source) miał na celu ocenę poziomu wymycia składników pokarmowych (azotu i fosforu) do wód z obszarowych ognisk zanieczyszczeń (głównie terenów rolniczych).W ramach projektu, realizowanego w latach 2001–2006, starano się wypracować jednolitą metodykę tej oceny, umożliwiającą korzystanie z niej przez wszystkie kraje Unii Europejskiej. Konieczność oceny poziomu wymycia azotu i fosforu wynika z zaleceń dyrektywy azotanowej i Ramowej Dyrektywy Wodnej. Jest to szczególnie istotne przy wyznaczaniu obszarów szczególnie wrażliwych na wymycie azotanów do wód podziemnych i powierzchniowych, a także kontrolowaniu efektywności projektowanych Programów Działań i ocenie trendów zmian zanieczyszczenia związkami azotu.W ramach projektu EUROHARP realizowano 9 modeli oceny poziomu wymycia azotu i fosforu w 17 obszarach badawczych zlokalizowanych w 8 krajach UE.W artykule przedstawiono skrócony opis wybranych modeli, które mogłyby zostać zastosowane w warunkach polskich, oraz przedstawiono uzyskane w efekcie modelowania wielkości wymywanych ładunków zanieczyszczenia w obszarach testowych o warunkach klimatycznych i glebowych zbliżonych do polskich.
The EUROHARP project (Towards European Harmonized Procedures for Quantification of Nutrient Losses from Diffuse Source) aimed at providing results of nutrient losses (nitrogen, phosphorus) from diffuse sources (agricultural land) to surface water. The project was executed in 2001–2006. Within the EUROHARP, different methodologies (quantification tools) for estimating nutrient looses were tested in European catchments. Quantification of nutrient looses is necessary for the Nitrates Directive and the Water Framework Directive implementation, especially for Nitrate Vulnerable Zone delimitation. EUROHARP includes nine different methodologies which have been applied in 17 study catchments from 8 European countries. The summarized description of select balance models, which could be used for nitrate leaching are presented. The paper shows modelling results from the catchments with Polish agricultural and hydrological conditions similar to those in Poland.
Źródło:
Biuletyn Państwowego Instytutu Geologicznego; 2008, 431, Hydrogeologia; 305--317
0867-6143
Pojawia się w:
Biuletyn Państwowego Instytutu Geologicznego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wymywanie zasobów ludzkich barierą rozwoju regionów peryferyjnych (na przykładzie województwa podlaskiego)
The backwash effects as a barrier to the development of peripheral regions on the example Podlaskie Province
Autorzy:
Zimnoch, K.
Powiązania:
https://bibliotekanauki.pl/articles/398953.pdf
Data publikacji:
2013
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
rozwój regionalny
regiony peryferyjne
kapitał ludzki
wypłukiwanie zasobów
polityka regionalna
regional development
outermost regions
human capital
leaching of resources
regional policy
Opis:
W ciągu dwudziestu lat prowadzenia gospodarki rynkowej w Polsce zmniejszyło się zróżnicowanie międzyregionalne poziomu rozwoju. Szybki rozwój gospodarczy kraju odczuły głównie obszary określane jako metropolitarne. W literaturze przedmiotu zapisano również prognozy wskazujące na utrzymywanie się tendencji szybszego wzrostu gospodarczego i umacniania się pozycji „centrów” w stosunku do regionów peryferyjnych. Dyskutowany aktualnie polaryzacyjno - dyfuzyjny model kładzie nacisk na wewnętrzne źródła rozwoju w regionach peryferyjnych. Najważniejszym czynnikiem staje się wobec tego miejscowy kapitał ludzki. Dla lokalnej polityki regionalnej wielkim wyzwaniem będzie więc zahamowanie trendów migracyjnych drenujących zasoby wykształconych i przedsiębiorczych młodych ludzi z regionów peryferyjnych. Do takich obszarów należy województwo podlaskie, w którym wyraźnie widać wypłukiwanie zasobów kapitału ludzkiego, a wraz z tym i kapitału finansowego. Województwo podlaskie pod względem poziomu rozwoju społeczno-gospodarczego zajmuje przedostatnie miejsce w kraju. W dokumencie rządowym Raport Polska 2030 – wyzwania rozwojowe, uważanym za podstawę tworzenia Krajowej Strategii Rozwoju Regionalnego zostało zaliczone do kategorii B – obszarów peryferyjnych, gdzie rozwój ma przebiegać na zasadzie procesu dyfuzji efektów wzrostowych w centrach. W tak programowanym rozwoju województwa podlaskiego uwidacznia się bariera w postaci efektów wymywania zasobów ludzkich. W województwie podlaskim proces ten następuje od wielu lat. Zjawisko wymywania przejawia się w spadku liczby mieszkańców w poszczególnych podregionach, powiatach i gminach, a szczególnie w spadku odsetka kobiet w grupie wiekowej 19-29 lat w ogólnej populacji, a także w rosnącym odsetku kobiet z tej grupy wiekowej na migracji wewnętrznej i zewnętrznej.
Podlaskie Province in terms of level of socio-economic development takes place before the last one in the country. For the government document "Report Poland 2030 - Development Challenges", considered the foundation for developing the National Strategy for Regional Development, Podlaskie was assigned to Category B - peripheral areas where development is to proceed on a process of diffusion effects in the growth centers. This means that only the use of endogenous sources of growth in the form of internal resources of the region. And abandoning redistributive practices in regional policy. This development program has its limitations. One of them is the effect of 'leaching' of human resources. The concept of the backwash effect was introduced to the theory of regional development by G. Myrdal in 1957. G. Myrdal by backwash effect means any significant adverse changes in trade, migration, capital movements, which operate centripetally causing recessionary processes in less developed regions and increasing their distance in relation to the growth poles. In the province of Podlaskie the backwash effect is the ongoing process for many years. This phenomenon manifests itself in a fall in the number of inhabitants in the different subregions, counties and municipalities, the decline in the percentage of women in the age group from 19 to 29 in the general population and the growing proportion of women in this age group in the external and internal migration. An additional manifestation of these processes is "sucking" of labor resources through the poles of growth, revealing a balance of internal and external migration - with a large positive value in the centers and a large negative value in remote areas. Among those who emigrate, leaving the Podlaskie Province over 57% are women. Among immigrants aged 20-24 is two times more women than men. At the beginning of the XXI century, the towns and cities of Podlaskie have a greater outflow than inflow of population. But under a polarizing development model of growth cities are its main source. This article aims to identify barriers to the development of Podlaskie based on endogenous sources, as their resources, especially when labor resources and human capital are shrinking due to the backwash effects. Despite the expenditure incurred by residents for education, the effects of this investment goes to the center along with the 'washing' of human resources. That is redistribution of income from poorer regions, with small resource capital to richer with large pools of capital and favorable labor market situation.
Źródło:
Ekonomia i Zarządzanie; 2013, 5, 3; 206-220
2080-9646
Pojawia się w:
Ekonomia i Zarządzanie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wymywanie metali ciężkich z odpadów pobranych z hałdy wałbrzyskiej - badania wstępne
The leaching of heavy metals from waste collected from the Wałbrzych heap - preliminary research
Autorzy:
Zielińska, Amelia
Powiązania:
https://bibliotekanauki.pl/articles/31342928.pdf
Data publikacji:
2023
Wydawca:
Poltegor-Instytut Instytut Górnictwa Odkrywkowego
Tematy:
wymywanie
odpad górniczy
metale ciężkie
leaching
mining waste
heavy metals
Opis:
Celem pracy było określenie wartości wymywania wybranych metali ciężkich z odpadów pochodzących z hałd wałbrzyskich. Próbki pobranych materiałów rozdrobniono na frakcje poniżej 4 oraz poniżej 1, które następnie poddano wymywaniu, a w powstałym eluacie oznaczono zawartość Cd, Cr, Cu, Ni, Pb, Zn. Wartości stężeń metali są poniżej granic oznaczalności. Na tej podstawie stwierdzono, że migracja metali ciężkich z odpadów pogórniczych do środowiska wodnego jest nieznaczna i nie powinna stanowić istotnego problemu. Badania wymagają jednak kontynuacji dla zróżnicowanych warunków wymywania.
The aim of the work was to determine the leaching value of selected heavy metals from waste from Wałbrzych heaps. Samples of collected materials were crushed into fractions below 4 and below 1 mm, which were then subjected to leaching, and the content of Cd, Cr, Cu, Ni, Pb, Zn, was determined in the resulting eluates. Metal concentration values are below the limits of quantification. On this basis, it was found that the migration of heavy metals from post-mining waste to the aquatic environment is insignificant and should not be a relevant issue. However, research needs to be continued for different leaching conditions.
Źródło:
Górnictwo Odkrywkowe; 2023, 64, 3; 4-8
0043-2075
Pojawia się w:
Górnictwo Odkrywkowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Beneficiation of Ga from alunite concentrates by selective acid leaching and alkaline precipitation
Autorzy:
Zhu, Mao-Lan
Chen, Hang
Zhong, Shui-Ping
Huang, Zhong-Sheng
Chen, Xi
Hu, Zhi-Biao
Powiązania:
https://bibliotekanauki.pl/articles/110733.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
gallium
selective leaching
precipitation
alunite concentrate
Opis:
In this study beneficiation of Ga from alunite ore was investigated. The effects of the calcination temperature, H2SO4 concentration, leaching temperature and liquid-solid ratio on the dissolution characteristic of Ga, K and Al were studied. The results showed that increasing the calcination temperature, H2SO4 concentration and leaching temperature can improve the solubility of K and Al. However, higher H2SO4 concentration and lower leaching temperature can improve the dissolution of Ga, which was beneficial to recovery of Ga. On the basis of the solubility difference in H2SO4, a two-stage process of selective acid leaching and alkali precipitation of Ga was proposed. The concentration of Ga was increased significantly from 54 g/t in alunite ore to 4100 g/t in alkali precipitation product. The major elements of Al and K in alunite were recovered as the alum crystal with a purity of 99.62%.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 4; 1028-1038
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An experimental study of removing impurity from a quartz ore by microbial flotation-acid leaching
Autorzy:
Zhu, Jujian
Dai, Shujuan
Li, Pengcheng
Yang, Shuyong
Powiązania:
https://bibliotekanauki.pl/articles/1448443.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
quartz purification
flotation
acid leaching
waste bacteria
Opis:
The purity of a quartz ore is relatively low at a $SiO_2$ content of 97.18%, and the main impurity in the ore is $Fe$, $Al$, and $Ca$ bearing minerals. The main component in an industrial waste bacteria (WJ) is polysaccharides, which may be used as depressors for inhibiting iron minerals in quartz flotation. Moreover, WJ belongs to microbial inhibitors because it is mainly composed of bacteria. As a result of this study, a concentrate grade of 99.88% at recovery over 80% was obtained under the condition of 2000 g/Mg WJ dosage, a grinding fineness of 70% -0.074 mm, pH 11.7, 400 g/Mg $CaCl_2$, and 800 g/Mg $NaOL$ in the flotation experiments for the quartz ore. Moreover, a $SiO_2$ grade of 99.97% at a recovery of 68.85% was obtained at an acid dosage of 40 kg/Mg by using mixed acid of $H_2SO_4$, $HCl$, $HNO_3$, and $HF$ in mass ratios of 20%, 30%, 20%, and 30%, respectively, in subsequent acid leaching of the quartz flotation concentrate. Zeta potential analysis before and after the interaction of quartz and hematite with WJ showed that WJ increased the zeta potential of hematite significantly but had little impact on the zeta potential of quartz, indicating stronger adsorption of WJ on hematite than on quartz. FTIR analysis showed that there exist not only –$COOH$, –$CH_2$–, and –$CH_3$, which are the functional groups of starch but also $NH_2$ and –$C=O-NH$– in WJ. The $NH_2$ and –$C=O-NH$– in WJ are the important groups for adsorption, so the depressing effect on hematite was better for WJ than starch.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 1; 18-28
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation study on clogging of suspended particles in in-situ leaching of uranium at different concentrations and flow velocity
Autorzy:
Zhou, Chunze
Wang, Hongqiang
Wu, Tongpan
Hu, Eming
Lei, Zhiwu
Wang, Qingliang
Powiązania:
https://bibliotekanauki.pl/articles/24085848.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
in-situ leaching of uraniom
physical clogging
suspended particles
porous medium
permeability coefficient
Opis:
Clogging problem has become one of the key problems restricting the mining efficiency of in-situ leaching of uranium, and the related research on the law and mechanism of physical clogging has not been reported. In order to identify and understand the complicated law and mechanism, experimental device is established to simulate the physical clogging caused by suspended particles in the uranium process, the physical clogging law and mechanism under different concentrations and velocity of flow are studied. The experimental results show that with the concentration of suspended particles increasing from 100, 200, 300 to 400 mg/L, the permeability of porous media gradually decreases, and the clogging phenomenon becomes more and more obvious. When the size of suspended particles is small and the velocity is 15 mL/min, the porous medium will not appear clogging, while the velocity is 25mL/min, the whole porous medium will slowly appear internal deposition clogging. When the size of suspended solids is larger and the flow rate is 9, 12, 15mL/min, the higher the velocity, the faster the clogging will be, and backwash can alleviate the surface clogging but cannot change the final clogging result. According to the experiment and actual situation, the physical clogging in in-situ leaching of uranium is mainly surface clogging and filter clogging.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 162150
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An innovative technology for recovery of zinc, lead and silver from zinc leaching residue
Autorzy:
Zheng, Y.-X.
Lv, J.-F.
Liu, W.
Qin, W.-Q.
Wen, S.-M.
Powiązania:
https://bibliotekanauki.pl/articles/110688.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
zinc leaching residue
lead sulfate
zinc sulfate
reduction roasting
flotation
Opis:
Zinc leaching residue is a good source of zinc and has a great potential to be utilized. However, it is very difficult to recover lead, zinc and silver from the residue by traditional technologies. In this study, a new technology based on conversions of PbSO4 and ZnSO4 in the residue to their respective sulfides by reduction roasting with coal powder followed by a flotation treatment was developed. The effects of roasting temperature, coal dosage, reaction time and pyrite dosage were investigated at a laboratory scale. The results showed that the conversion extent of PbSO4 and ZnSO4 under the optimal experimental conditions was 71.89 and 69.76%, respectively. A flotation concentrate containing 39.13% Zn, 6.93% Pb and 973.54 g/Mg Ag was obtained from the treated material, and the recovery of Zn, Pb and Ag was 48.38, 68.23 and 77.41%, respectively. The tailing containing ZnFe2O4 or Fe3O4 could be either stockpiled or further disposed.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 2; 943-954
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calcination of Aluminum Chloride Hexahydrate (ACH) for Alumina Production: Implications for Alumina Extraction from Aluminum Rich Fly Ash (ARFA)
Autorzy:
Zhao, L.
Powiązania:
https://bibliotekanauki.pl/articles/354384.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
calcination
aluminum chloride hexahydrate
alumina rich fly ash
acid leaching
Opis:
Alumina rich fly ash (ARFA) has been regarded as the alternative to bauxite in China. Hydrochloric acid process could be favored for alumina extraction, necessitating calcination of aluminum chloride hexahydate (ACH). In this work, the TGA/DSC results of ACH were used to suggest calcination procedures. Two-step calcinations of 200-1000°C and 350-1000°C did not increase the surface area of alumina, by comparison with one step 1000°C calcination, and a slow heating rate could improve the surface area. Calcination temperature was increased from 950 to 1250°C in a step of 50°C, and XRD, XRF, BET and gas pycnometer were used to characterize the alumina from calcinated ACH. Consistent results were obtained by these different techniques, and two groups of impurities were identified and related to alumina purity and surface area. By comparison with clays, it was suggested to remove impurities such as MgO, Na2 O, K2 O, P2 O5 and SO3 in hydrochloric acid leaching of ARFA.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 235-240
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the breakthrough phenomena during heavy metal elution from a column packed with municipal waste incineration ash
Autorzy:
Zhang, W.
Yang, Y.
Suganuma, H.
Kato, S.
Suzuki, S.
Kojima, T.
Powiązania:
https://bibliotekanauki.pl/articles/206904.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
calcium compounds
dissolution
heavy metals
leaching
particle size
związki wapnia
rozpuszczanie
metale ciężkie
ługowanie
wielkość cząstek
Opis:
At some point during acid leaching column tests of heavy metals from municipal waste incineration ash, sudden and rapid elution of harmful elements was observed which was called the breakthrough (BT) phenomena. The mechanism was elucidated from the results of measurement of elemental and particle size distribution in the column and batch leaching tests as follows. At the first stage of experimental runs, CaCO3 was dissolved in acidic solution and pH profile along the bed is formed. Some of the minor elements of Zn and Al dissolved by acid at the upper part of the column are precipitated at bottom of the column, leading to the reduction of flow rate of the leachate solution. After leachate pH becomes low by the termination of dissolution of Ca, these deposits are dissolved and thus, the flow rate increases. Most of the trace elements behave as such, which causes the increase of harmful element concentrations in the eluate. Some drastic concentration increase of harmful elements in leachate may occur even after the long period of pseudo stable dissolution behavior in the land-fill site.
Źródło:
Environment Protection Engineering; 2018, 44, 3; 63-78
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetics and mechanism of one-step reductive leaching of manganese oxide ores by EDTA/EDTA-2Na
Autorzy:
Zhang, C.
Wang, S.
Cao, Z.
Zhong, H.
Powiązania:
https://bibliotekanauki.pl/articles/109834.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kinetics
EDTA
reductive leaching
manganese oxide ores
EDTA-2Na
Opis:
In this research, the kinetics and mechanism of one-step reductive leaching of manganese oxide ores by ethylenediaminetetraacetic acid (EDTA) or its disodium salt (EDTA-2Na) in an aqueous medium have been investigated. The kinetic data of this reductive leaching process may be described by the Avrami model, and the apparent activation energy was determined to be 15.8 kJ·mol-1/7.9 kJ·mol-1 for leaching by EDTA/EDTA-2Na with a reaction order of -1.7/2.0. The EDTA/EDTA-2Na leach liquor characterized and analyzed by X-ray photoelectron spectra (XPS), Fourier transform infrared spectra (FTIR), and total organic carbon (TOC) determination denoted that the oxidation-reduction reaction happened between manganese(IV) and EDTA/EDTA-2Na, and a coordination complex, EDTA-manganese(II/III) formed. This new process can be easily used to leach manganese from manganese oxide ores in a moderate environment with the pH range of 5–8.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 858-867
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dissolution of alkaline batteries in reductive acidic media
Autorzy:
Zeytuncu, B.
Powiązania:
https://bibliotekanauki.pl/articles/110179.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
alkaline battery
manganese
zinc
reductive leaching
sulfur
Opis:
In this paper, recovery of manganese and zinc from alkaline battery paste by leaching under atmospheric condition using elemental sulfur as a reductive agent and sulfuric acid was investigated. Different dissolution parameters, acid concentrations, liquid-to-solid ratios, reaction temperatures, leaching times and amounts of elemental sulfur were studied in detail. According to results, the Mn dissolution in reductive acidic media was an intermediate-controlled process with activation energy of 10.21±2.60 kJ/mol. After the leaching step, Mn and Zn were selectively precipitated from the leaching solution using sodium hydroxide. After solid/liquid separation, manganese(II,III) oxide (Mn3O4) was obtained by drying at 105 °C in air. Next, Mn3O4 was converted to manganese(IV) oxide (MnO2) by heating at 800 °C in air. After that the solution containing Zn(OH)42- was treated with sulfuric acid to form zinc hydroxide, separated and next converted to zinc oxide by heating at 600 °C in air. The final products were characterized by XRD. The results showed that the proposed process can be effectively used for recovery of Mn and Zn from alkaline batteries.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 437-450
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The recovery of rare-earth metals from fly ash using alkali pre-treatment with sodium hydroxide
Odzysk metali ziem rzadkich z popiołów lotnych przy zastosowaniu wstępnej obróbki alkalicznej wodorotlenkiem sodu
Autorzy:
Żelazny, Sylwester
Świnder, Henryk
Jarosiński, Andrzej
Białecka, Barbara
Powiązania:
https://bibliotekanauki.pl/articles/216035.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
fly ash
rare earth metals
leaching
popiół lotny
metale ziem rzadkich
ługowanie
Opis:
The aim of the work was to draw attention to the usefulness of the alkaline thermal activation process with sodium hydroxide in the process of rare earth metal leaching (REE), from fly ash with hydrochloric acid and nitric acid(V). The work is a part of the authors’ own research aimed at optimizing the REE recovery process coming from fly ash from hard coal combustion. The article contains an assessment of the possibility of leaching rare earth metals (REE) from fly ash originating from the combustion of hard coal in one of the Polish power plants. The process was carried out for various samples consisting of fly ash and sodium hydroxide and for different temperatures and reaction times. The process was carried out for samples consisting of fly ash and sodium hydroxide containing respectively 10, 20 and 30% on NaOH by weight in relation to the weight of fly ash. Homogenization of these mixtures was carried out wet, and then they were baked at 408K, 433K and 473K, for a period of three hours. The mixture thus obtained was ground to a particle size of less than 0.1 mm and washed with hot water to remove excessive NaOH. The solid post-reaction residue was digested in concentrated HCl at 373K for 1 hour at a weight ratio fs/fc of 1:10. The results of chemical analysis and scanning microscopic analysis along with EDS analysis and X-ray analysis were used to characterize the physicochemical properties of the tested material. The results indicated that REE recovery from fly ash strictly depends on heat treatment temperature with NaOH, and an increase in REE recovery from alkaline-activated fly ash along with increasing the amount of NaOH in relation to fly ash mass.
Celem pracy było zwrócenie uwagi na przydatność alkalicznego procesu aktywacji termicznej wodorotlenkiem sodu w procesie ługowania metali ziem rzadkich (REE) z popiołu lotnego z kwasem chlorowodorowym i azotowym (V). Praca jest częścią badań własnych autorów mających na celu optymalizację procesu odzyskiwania REE z popiołów lotnych ze spalania węgla kamiennego. Artykuł zawiera ocenę możliwości ługowania metali ziem rzadkich (REE) z popiołów lotnych pochodzących ze spalania węgla kamiennego w jednej z polskich elektrowni. Proces przeprowadzono dla próbek składających się z popiołu i wodorotlenku sodu zawierającego odpowiednio 10, 20 i 30% wagowych NaOH w stosunku do masy popiołu. Homogenizację tych mieszanin przeprowadzono na mokro, a następnie spiekano je w temperaturze 408K, 433K i 473K przez okres trzech godzin. Tak otrzymaną mieszaninę zmielono do wielkości cząstek mniejszej niż 0,1 mm, a następnie przemyto gorącą wodą w celu usunięcia nadmiaru NaOH. Stałą pozostałość poreakcyjną trawiono stężonym HCl w temperaturze 373K przez 1 godzinę, przy stosunku wagowym fs/fc wynoszącym 1:10. Wyniki analizy chemicznej i skaningowej analizy mikroskopowej wraz z analizą EDS i analizą rentgenowską wykorzystano do scharakteryzowania właściwości fizykochemicznych badanego materiału. Otrzymane wyniki wskazują, że odzysk REE z popiołu zależy ściśle od temperatury obróbki cieplnej za pomocą NaOH, oraz że odzysk REE z popiołu aktywowanego alkalicznie rośnie wraz ze wzrostem ilości NaOH w stosunku do masy popiołu.
Źródło:
Gospodarka Surowcami Mineralnymi; 2020, 36, 3; 127-144
0860-0953
Pojawia się w:
Gospodarka Surowcami Mineralnymi
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identyfikacja wymywania azotu na podstawie badań chemizmu wód w rolniczych systemach drenarskich na przykładzie Wysoczyzny Kałuszyńskiej
Identification of nitrogen leaching based on water chemistry studies in agricultural drainage systems in the Kałuszyn Upland
Autorzy:
Zabłocki, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2075615.pdf
Data publikacji:
2017
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
system drenarski
wymywanie azotu
azotany
obszar rolniczy
Wysoczyzna Kałuszyńska
drainage system
nitrogen leaching
nitrates
agricultural area
Kałuszyn Upland
Opis:
The paper presents the water chemistry from subsurface drainage systems located in an agricultural area. Studies have shown a significant degree of transformation of chemical composition, observed in a hydrochemical multi-ionic type, in which nitrates play the main role. This is the predominant form of mineral nitrogen in the water and accounts for an average of 95%, which corresponds to a concentration range of 11.07 to 47.82 mg/dm3. Field studies were the basis for determining the reliability of the theoretical model for the distribution ofnitrogen loading leached from soils. Loading was computed on the basis of statistical data concerned average annual fertilizer usage expressed as a pure component, and data from own research on the estimation of nitrogen leaching rate. Nitrogen loadings in the range of 1.54-13.17 kgN/ha-year was converted to the expected nitrate concentrations in infiltration waters through the vadose zone, taking into account the average infiltration recharge. The expected nitrate concentration range of 1.69 to 120.00 mg/dm3 (with the concentrations above 50 mg/dm3 observed in 18.4% of the area) may be the basis for designing the most vulnerable areas (OSN) for nitrogen leaching to surface water and groundwater.
Źródło:
Przegląd Geologiczny; 2017, 65, 11/2; 1398--402
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Leaching kinetic study of Y and Eu from waste phosphors using hydrochloric acid solution containing hydrogen peroxide
Autorzy:
Yu, M.
Jiang, Z.
Mei, G.
Chen, X.
Powiązania:
https://bibliotekanauki.pl/articles/949690.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
waste phosphors
leaching
kinetics
rare earth elements
Opis:
The leaching kinetics of Y and Eu from waste phosphors using a hydrochloric acid (HCl) solution containing hydrogen peroxide (H2O2) were investigated. Characterization of the waste phosphors was performed using XRD to ascertain the phases as (Y0.95Eu0.05)2O3 (red phosphors), (Ce0.67Tb0.33)MgAl11O19 (green phosphors), (Ba0.9Eu0.1)Mg2Al16O27 (blue phosphors), and SiO2 (quartz). The influence of factors such as HCl concentration, addition amount of H2O2, temperature, and reaction time on the leaching performance of Y and Eu was investigated. The maximum leaching recoveries of Y (99.87%) and Eu (88.72%) were obtained at 4 M HCl, 0.2 cm3/g H2O2, 60 ℃ temperature, and 180 min of reaction time at a liquid-to-solid ratio of 7.5 cm3/g. Leaching kinetic results showed the best fit with the shrinking sphere model (1-(1-x)1/3)=kct), ensuring that the overall leaching process was governed by a chemical control mechanism. Activation energies of 42.35 and 33.28 kJ/mol were acquired for leaching of Y and Eu, respectively, at 40-70 ℃, which further supports the proposed chemical control leaching process.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 238-248
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

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