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Tytuł:
Enhanced effect of fine magnetite on the flotation performance of fine hematite in sodium oleate system
Autorzy:
Pei, Bin
Luo, Ximei
Yang, Wen
Wei, Dayong
Li, Chao
Wang, Yunfan
Powiązania:
https://bibliotekanauki.pl/articles/2146908.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
magnetite
hematite
flotation
magnetic aggregation
Opis:
In this work, the effect of magnetite with different particle sizes on the flotation performance of both coarse and fine hematite particles were investigated by using sodium oleate as a collector. The results showed that the magnetite particles with different particle sizes showed a negative effect on hematite (-106+45 μm) recovery, but the addition of magnetite with the same particle sizes as hematite during the direct flotation of -45 μm hematite was beneficial to improve the recovery of micro-fine hematite and the Fe grade of concentrate. The finer the magnetite particle was, the more obvious the agglomeration effect of hematite was. Therefore, the beneficial effect could be achieved by adjusting the particle sizes of particles. Moreover, sodium oleate was beneficial to promote the agglomeration of micro-fine magnetite and hematite. The results from the microscopic analysis, laser particle size analysis, and EDLVO calculation proved that there was an effective aggregation between fine magnetite and fine hematite particles, which increased the apparent size of hematite particles and the probability of the mineral particles adhering to bubbles, thus improving the hematite recovery.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 4; art. no. 149673
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
UO2 nanoparticles synthesis from leaching solutions on the hematite support
Autorzy:
Sadowski, Zygmunt
Sklodowska, Aleksandra
Powiązania:
https://bibliotekanauki.pl/articles/763988.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
bioleaching, nanoparticles, hematite, zeta potential, uranium oxide
Opis:
In the present studies the bacterial leaching process is used to extract uranium from the uranium mining wastes. The bioleaching process is environment friendly and gives the extraction yield of over 90%. The bioleaching solutions were obtained from the waste materials located at different places at Lover Silesia (Kowary, Grzmiąca, Kopaniec). Among various templates the hematite Fe2O3 nanoparticles are most useful. Interactions uranium ions with synthesized nanoparticles of hematite, magnesite, and iron were examined. 
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia; 2016, 71, 1
2083-358X
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Physicochemical study and application for pyrolusite separation from high manganese-iron ore in the presence of microorganisms
Autorzy:
Farghaly, Mohamed Galal
Abdel-Khalek, Nagui Aly
Abdel-Khalek, Mohamed Abdel-Dayem
Selim, Khaled Abdelaal
Abdullah, Samah Saleh
Powiązania:
https://bibliotekanauki.pl/articles/1448933.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
iron ore
bioflotation
pyrolusite
hematite
Paenibacillus polymyxa
Opis:
Paenibacillus polymyxa bacteria strain as a surface modifier in a flotation process could remove 64.89% of $MnO_2$ from high manganese iron ore. A concentrate containing 3.7% $MnO_2$, 0.5% $SiO_2$ and 71.30% $Fe_2O_3$, with a hematite recovery of 72.46% is produced from a feed containing 8.79% $MnO_2$, 0.49% $SiO_2$ and 67.90% $Fe_2O_3$. The bio-flotation results indicated that such type of bacteria is selective for upgrading El-Gedida iron ore from the Western Desert of Egypt. The role of Paenibacillus polymyxa on the surface properties of pyrolusite and hematite single minerals was investigated through zeta potential, FTIR and adsorption measurements.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 1; 273-283
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations on soluble starch as the depressant of hematite during flotation separation of apatite
Autorzy:
Bai, Shaojun
Ding, Zhan
Fu, Xianyu
Li, Chunlong
Lv, Chao
Wen, Chao
Powiązania:
https://bibliotekanauki.pl/articles/110115.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
soluble starch
depressant
hematite
apatite
FTIR
XPS
Opis:
In this paper, soluble starch was studied as a depressant of hematite during flotation separation of apatite using sodium oleate as a collector. Surface charge measurement, soluble starch adsorptions, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to understand the interaction mechanisms between minerals (hematite and apatite) and soluble starch. The results indicated that chemical interaction between hematite and soluble starch was present, and supported the bonding of hydroxyl, while physical adsorption of soluble starch molecules with apatite occurred. Results of micro-flotation studies suggested that soluble starch was considered as a selective depressant for hematite. The maximum recovery difference between hematite and apatite of 77.5% was obtained with 40 mg/dm3 soluble starch. The flotation experiment results of natural iron ore showed that flotation indexes with 59.73% Fe, iron recovery of 81.5% and 75.68% of dephosphorization ratio were achieved at a soluble starch dosage of 60 mg/dm3. However, a higher dosage of soluble starch addition caused the difficulty for flotation separation of apatite from hematite. Our results provided theoretical basis for the flotation separation of apatite from iron oxide ores.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 38-48
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mineral preconcentration using near infrared sensor-based sorting
Autorzy:
Iyakwari, S.
Glass, H. J.
Powiązania:
https://bibliotekanauki.pl/articles/109720.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
near infrared
copper
hematite
preconcentration
strategy
intimate mixtures
moisture
Opis:
This paper predicts qualitatively and quantitatively the near infrared activity of individual minerals in simple and complex mineral associations using mixtures of common alteration minerals found in a copper ore. It was found that spectra dominance in most cases is dependent on any or combination of mineral composition, relative proportion or concentration and/or mineral accessibility or sensitivity to near infrared radiation. The analysis of results also indicated that, in most cases, only freely occurring waste, such as clays (kaolinite and/or muscovite) and calcite, can be targeted for discrimination. In this paper, a strategy for the application of near infrared for preconcentration of copper bearing minerals like chrysocolla and malachite from coarse ore particles was proposed. Other applications also considered in this paper include preconcentration of hematite from associated clays and carbonate waste, and the determination of moisture content in kaolinitic clays.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 2; 661-674
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selective flotation of siderite and quartz from a carbonate-containing refractory iron ore using a novel amino-acid-based collector
Autorzy:
Gu, X.
Zhu, Y.
Li, Y.
Han, Y.
Powiązania:
https://bibliotekanauki.pl/articles/110222.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
quartz
hematite
siderite
refractory iron ores
molecular simulation
Opis:
A novel and highly-efficient amino-acid-based collector, α-ethylenediamine lauric acid (α-EDA-LA), was studied to selectively beneficiate carbonate-containing refractory hematite ores. Single mineral and synthetic mixture flotation tests were carried out to investigate its floating performance. Zeta potential, fourier transform infrared spectroscopy (FTIR) and Density Functional Theory-based molecular simulation were used to identify the adsorption mechanism. The flotation results showed that quartz could be collected effectively at pH 11.0-12.0 in the reverse flotation. For siderite, the recovery peaked at 83.4% at pH 8.0, where siderite presented different floatability from magnetite and hematite. Exploiting such difference, the separation of siderite could be achieved. Zeta-potential measurements showed that α-EDA-LA adsorption on the surfaces of siderite and quartz decreased the corresponding zeta potentials at pH of 8.0-10.0 and 8.0-12.0, respectively. This means the adsorption overcome the electrostatic repulsion between α-EDA-LA and the mineral surfaces. The molecular simulation indicated that no chemisorption took place between α-EDA-LA and quartz. FTIR analysis suggested that α-EDA-LA was adsorbed on quartz via hydrogen bonding. The adsorption of α-EDA-LA on siderite surface was dominated by chemisorption, while further enhanced by hydrogen bonding. This study filled the gap in the research on siderite flotation reagents and its adsorption mechanism.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 803-813
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect and mechanism of citric acid on flotation separation of siderite and hematite
Autorzy:
Han, Huili
Yin, Wanzhong
Yao, Jin
Li, Dong
Powiązania:
https://bibliotekanauki.pl/articles/949693.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
siderite
hematite
citric acid
dispersion
flotation
E-DLVO theory
Opis:
Heterocoagulation can occur between fine siderite and hematite particles, which would result in the low efficiency of their separation during the flotation process. To date, there have been no mature methods to increase their separation efficiency. In this paper, citric acid was used as a regulator to enhance the slurry dispersion efficiency. Micro-flotation, scanning electron microscopy (SEM) analysis, settling tests, particle size measurements, zeta potential measurements and E-DLVO theoretical calculations were conducted in the investigations. A maximum recovery difference (53.98%) between siderite and hematite in their mixtures flotation was obtained. Settling tests confirmed that citric acid contributed to improving the dispersion degree of the slurry. SEM analysis indicated that citric acid could clean the surface of particles and weaken the coagulation between siderite and hematite, which were in line with the results of particle size measurements. The zeta potential measurements and Extended-Derjaguin-Landau-Verwey-Overbeek (E-DLVO) theoretical calculations indicated that the citric acid could adsorb on the siderite and hematite surfaces and decreased the surface charge, resulting in a visible increase of the repulsion energy between siderite and hematite particles. Therefore, citric acid can be applied to remove the easily-ground carbonate minerals first to improve the flotation performance of hematite in the separation process of carbonate-containing iron ores.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 311-323
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mobility of interacting inorganic nanoparticles
Autorzy:
Dziedzic-Kocurek, K.
Fornal, P.
Stanek, J.
Powiązania:
https://bibliotekanauki.pl/articles/146259.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
dynamic light scattering
hematite nanoparticles
mobility
Mössbauer spectroscopy
viscosity
Opis:
The mobility of the 110 nm-Fe2O3 particles in a viscous sucrose solution depends on the concentration of the nanoparticles. When the average particle–particle nearest neighbor distance is less than 250 nm, the particle interaction slows down their mobility. When is more than 170 nm, the small mobility of nanoparticles does not depend on their concentration. The critical distance is approximately equal to 2Rh = 260 nm, where Rh is the hydrodynamic radius, determined by the dynamic light scattering (DLS) method.
Źródło:
Nukleonika; 2015, 60, 1; 19-22
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of particle size on flotation performance of hematite
Autorzy:
Luo, Ximei
Song, Shuixiang
Ma, Mingze
Wang, Yunfan
Zhou, Yongfeng
Zhang, Ying
Powiązania:
https://bibliotekanauki.pl/articles/109891.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
particle size
hematite
entrainment
surface bonding site
reagent adsorption
Opis:
The effect of particle size on flotation performance of hematite and quartz was investigated. Microflotation, X-ray photoelectron spectroscopy analysis, reagent adsorption measurements, and collision and attachment probability calculation between particle and bubble were conducted in this investigation. The results showed that the floatability of minerals with different particle size fractions was different, which was mainly related to surface bonding site, reagent adsorption, collision probability and entrainment. The quartz with different particle size had little impact on hematite recovery, but -45 μm fraction negatively affected Fe grade of concentrate both in the direct and reverse flotation of hematite. In the direct flotation, the Fe grade in froth product dropped off due to the fine quartz entrainment. While in the reverse flotation, the Fe grade in sink product dropped off as a result of difficulty in floating fine quartz particles, which was due to lower collision probability. Meanwhile, in the reverse flotation, the presence of hematite fines (-18 μm fraction) also had negative impact on hematite recovery because of fine particle entrainment.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 2; 479-493
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Depletion of intracellular glutathione and increased lipid peroxidation mediate cytotoxicity of hematite nanoparticles in MRC-5 cells
Autorzy:
Radu, Mihaela
Munteanu, Maria
Petrache, Sorina
Serban, Andreea
Dinu, Diana
Hermenean, Anca
Sima, Cornelia
Dinischiotu, Anca
Powiązania:
https://bibliotekanauki.pl/articles/1040384.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
MRC-5 cells
antioxidant enzymes
glutathione
lipid peroxidation
hematite nanoparticles
Opis:
Particles generated from numerous anthropogenic and/or natural sources, such as crystalline α-Fe2O3 nanoparticles, have the potential to damage lung cells. In our study we investigated the effects of these nanoparticles (12.5 µg/ml) on lipid peroxidation and the antioxidative system in MRC-5 lung fibroblast cells following exposure for 24, 48 or 72h. Exposure to α-Fe2O3 nanoparticles increased lipid peroxidation by 81%, 189% and 110% after 24, 48 and 72h, respectively. Conversely, the reduced glutathione concentration decreased by 23.2% and 51.4% after 48 and 72h of treatment, respectively. In addition, an augmentation of the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione transferase and glutathione reductase within the interval between 48-72h was noticed. Taking into account that the reduced glutathione level decreased and the malondialdehyde level, a lipid peroxidation product, remained highly increased up to 72h of exposure, it would appear that the MRC-5 antioxidant defense mechanisms did not efficiently counteract the oxidative stress induced by exposure to hematite nanoparticles.
Źródło:
Acta Biochimica Polonica; 2010, 57, 3; 355-360
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wstępne badania wykorzystania drobnej frakcji chalcedonitowej w technologiach ceramicznych
Preliminary studies on the use of fine fractions of chalcedonit in ceramic technologies
Autorzy:
Dziubak, C.
Tymowicz-Grzyb, P.
Powiązania:
https://bibliotekanauki.pl/articles/168217.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Ceramiki i Materiałów Budowlanych
Tematy:
chalcedonit
okluzja
hematyt
porowatość
kompozyt
chalcedonite
occlusion
hematite
porosity
composite
Opis:
Chalcedonit jest unikatowym surowcem krzemionkowym eksploatowanym ze złoża „Teofilów” w Inowłodzu. Specyficzne właściwości surowca, jak wysoka zawartość krzemionki bezpostaciowej oraz duża porowatość (do 25%) sprzyjają wbudowaniu cząstek składnika chromoforowego (Fe2O3) do porów i „zamykaniu go” w osnowie z SiO2 w procesie spiekania wysokotemperaturowego. Dla potwierdzenia i ilościowej oceny wbudowania Fe2O3 do matrycy z SiO2 stosowany jest test wymywalności składnika żelazowego ze struktury spieku w środowisku kwaśnym na gorąco. Otrzymany spiek barwny o charakterze kompozytu ma cechy obydwu składników jednocześnie. Podobnie jak kwarc jest odporny na chemiczne wpływy środowiska w wysokiej temperaturze oraz ma czerwonobrązowe zabarwienie pochodzące od barwy cząstek hematytu. Kolorystyka tworzywa ceramicznego (masa na płytki podłogowe) wyrażona za pomocą parametrów L*, a*, b* dowodzi trwałości barwy spieku, który pełni rolę pigmentu. Przedstawione wyniki badań mające charakter wstępnych, rokują na uzyskanie dobrych efektów okluzji hematytu w matrycy z SiO2 także w powiększonej skali procesu.
Chalcedonite is a unique siliceous material extracted from the Teofilów deposit in Inowłódz, Poland. Specific properties of the material, such as a high content of amorphous silicon dioxide and high porosity (up to 25%) promote an incorporation of the chromophore component (Fe2O3) particles into the pores and their “enclosure” in the SiO2 structure in the process of high-temperature sintering. The test method used for verification and quantitative evaluation of Fe2O3 incorporation into the SiO2 matrix is hot leaching of the ferric component from the sinter structure in an acidic environment. The obtained coloured sinter of a composite character displays the properties of both components simultaneously. Like quartz, it is resistant to chemical influences from the environment at high temperatures; also, it is red-brown due to the colour of the hematite particles. The colouration of the ceramic material (floor tile mass) expressed with the parameters: L*. a*, b*, proves colour stability of the sinter employed as a pigment. The presented study results of a preliminary nature promise good effects of hematite occlusion in the SiO2 matrix, also in largescale processes.
Źródło:
Szkło i Ceramika; 2017, R. 68, nr 6, 6; 6-10
0039-8144
Pojawia się w:
Szkło i Ceramika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of recycling blast furnace dust by magnetization roasting with straw charcoal as reductant
Autorzy:
Ju, Jinrong
Feng, Yali
Li, Haoran
Zhang, Qian
Powiązania:
https://bibliotekanauki.pl/articles/2146900.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
blast furnace dust
straw charcoal
magnetization roasting
hematite
zinc ferrite
Opis:
Blast furnace dust generated in the iron-making process not only contains a large amount of iron but also the widely used non-ferrous metal zinc, which is classified as hazardous waste. In this study, the process of recycling blast furnace dust by magnetization roasting with straw charcoal as the reductant is proposed, and the mechanism of magnetization roasting was explored through thermodynamic analysis, X-ray diffraction analysis, and thermogravimetric analysis. The results for the thermodynamic analysis showed that the reduction of blast furnace dust by the straw charcoal was feasible theoretically. The increase in the roasting temperature not only promoted the reduction of hematite (Fe2O3) but also reduced zinc ferrite (ZnFe2O4) to Fe3O4 and ZnO. The results showed that almost all Fe2O3 and ZnFe2O4 in the blast furnace dust were reduced to Fe3O4 and ZnO under the conditions of straw charcoal amount of 6%, the roasting temperature of 750℃, and the roasting time of 60 min. Then, the iron concentrate with the iron recovery of 85.61% and an iron grade of 63.50% was obtained by the magnetic separation. Meanwhile, the grade of zinc in the iron concentrate was 0.19%. Finally, the flowsheet of simultaneously recovering iron and zinc from the blast furnace dust was put forward, which could realize that 85.61% of iron was recovered and 92.57% of zinc was extracted into the solution.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 3; art. no. 149265
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison the Adsorption Capacity of Ukrainian Tuff and Basalt with Zeolite–Manganese Removal from Water Solution
Autorzy:
Trach, Yuliia
Tytkowska-Owerko, Marta
Reczek, Lidia
Michel, Magdalena M.
Powiązania:
https://bibliotekanauki.pl/articles/1839128.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
water treatment
natural sorbent
ion exchange minerals
saponite
hematite
andesine
Opis:
Manganese is an undesirable element in tap water but is common in the groundwater. Several methods can be used for manganese removal, including adsorption. Mined rocks are commonly evaluated as adsorbents and it was the objective of this paper – to investigate the Ukrainian volcanic tuff and basaltic rock from the Ivanodolinsky quarry and compare it with Ukrainian zeolite as well as with literature data. The research was based on equilibrated batch tests at a temperature of 10°C and slightly acidic pH. The data were treated using Langmuir and Freundlich models in the linear form. The results indicated the spontaneous and favourable adsorption of manganese. The volcanic tuff was characterized by the highest adsorption capacity, twice higher than basalt and zeolite. The heterogeneity of the active adsorption sites on the tuff was also greater and resulted from the diversity of the mineral composition. Considering the literature data, the properties of tuff are worth further research.
Źródło:
Journal of Ecological Engineering; 2021, 22, 3; 161-168
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mineralogy characteristics, stability conditions, and formation pathways of synthetic pyrrhotite formed by heating pyrite at 700℃
Charakterystyka mineralogiczna, warunki stabilności i ścieżki powstawania syntetycznego pirotynu utworzonego przez ogrzewanie pirytu w temperaturze 700℃
Autorzy:
Wang, Zhehao
Wang, Ling
He, Yuting
Duan, Jiongran
Fan, Bowen
Powiązania:
https://bibliotekanauki.pl/articles/2203296.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
synthetic pyrrhotite
pyrrhotite
pyrite
hematite
pirotyn syntetyczny
pirotyn
piryt
hematyt
Opis:
Pyrite is a sulfide mineral and is widely distributed in nature. Pyrite may transform into pyrrhotite when heated at high temperatures. In order to support processing engineering techniques and industrial applications of pyrite and pyrrhotite, it is necessary to investigate synthetic pyrrhotite, which is formed by heating pyrite in air, based on existing research. In this work, the mineralogical characteristics and stability conditions of synthetic pyrrhotite formed by heating pyrite at elevated temperatures were studied. The possible formation pathway was verified using a solid-phase reaction. X-ray-diffraction results revealed that synthetic pyrrhotite differs from natural pyrrhotite in the paragenetic association of minerals. Natural pyrrhotite and magnetite coexist in the natural pyrrhotite sample. Synthetic pyrrhotite formed by heating pyrite at 700℃ for 1 h has the paragenetic association with hematite and a small amount of pyrite and magnetite. All pyrrhotite samples were monoclinic pyrrhotite-4C (Fe7S8) and exhibit minimal differences in terms of lattice parameters. Synthetic pyrrhotite-4C was stable under 0.5–2 h of heating at 700℃ in air. It had the highest relative content by heating for 1 h. It was eventually transformed into hematite with heating periods exceeding 3 h, as was the case for pyrite and magnetite. In air, synthetic pyrrhotite-4C is mainly formed via two pathways: (1) pyrite → pyrrhotite-4C and (2) pyrite → magnetite → pyrrhotite-4C. Pathway (1) is more favorable than pathway (2). This transformation cannot be achieved by the reaction between hematite and sulfur.
Piryt jest minerałem siarczkowym szeroko rozpowszechnionym w przyrodzie. Piryt może przekształcić się w pirotyn podczas ogrzewania w wysokich temperaturach. W celu wsparcia technik inżynierii mineralnej i przemysłowego zastosowania pirytu i pirotynu, konieczne jest zbadanie syntetycznego pirotynu w oparciu o istniejące badania, który powstaje w wyniku ogrzewania pirytu w powietrzu. W pracy zbadano właściwości mineralogiczne i warunki trwałości syntetycznego pirotynu powstałego w wyniku ogrzewania pirytu w podwyższonej temperaturze. Możliwą ścieżkę powstawania zweryfikowano za pomocą reakcji w fazie stałej. Wyniki dyfrakcji rentgenowskiej ujawniły, że syntetyczny pirotyn różni się od naturalnego pirotynu w paragenetycznych asocjacjach minerałów. Naturalny pirotyn i magnetyt współistnieją w próbce naturalnego pirotynu. Syntetyczny pirotyn powstały w wyniku ogrzewania pirytu w temperaturze 700℃ przez 1 godz. wykazuje asocjację paragenetyczną z hematytem oraz niewielką ilością pirytu i magnetytu. Wszystkie próbki pirotynu były jednoskośnym pirotynem-4C (Fe7S8) i wykazują minimalne różnice pod względem parametrów sieci. Syntetyczny pirotyn-4C był stabilny w czasie 0,5–2 godzin ogrzewania w powietrzu w temperaturze 700℃. Najwyższą względną zawartość miał po ogrzewaniu przez 1 godzinę. Ostatecznie został przekształcony w hematyt z okresami ogrzewania przekraczającymi 3 godziny, podobnie jak w przypadku pirytu i magnetytu. W powietrzu syntetyczny pirotyn-4C powstaje głównie dwoma metodami: (1) piryt → pirotyn-4C i (2) piryt → magnetyt → pirotyn-4C. Ścieżka (1) jest korzystniejsza niż ścieżka (2). Tej przemiany nie można osiągnąć w reakcji hematytu z siarką.
Źródło:
Gospodarka Surowcami Mineralnymi; 2023, 39, 1; 23--34
0860-0953
Pojawia się w:
Gospodarka Surowcami Mineralnymi
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Classification techniques and parameter optimization of Cyclone Continuous Centrifugal Separator for hematite ore
Autorzy:
Zhang, Pei
Xie, Haiyun
Jin, Yanling
Chen, Jialing
Zeng, Peng
Li, Yuanhong
Chen, Luzheng
Liu, Dianwen
Powiązania:
https://bibliotekanauki.pl/articles/2200335.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hematite
Cyclonic Continuous Centrifugal Separator
CCCS
classification
Response Surface Methodology
Opis:
The Cyclonic Continuous Centrifugal Separator (CCCS) is a new type of separation equipment developed based on cyclonic continuous centrifugal separation technology and combined with the separation principle of the fluidized bed. Taking hematite as the research object, the main parameters and conditions of the best hematite classification were determined through the classification test by using CCCS. Based on the classification test, the significance order of each process parameter and their interaction with hematite classification efficiency of the underflow products was analyzed with the Response Surface Methodology, the optimal process parameter of hematite classification was obtained and a multiple regression equation was established. The optimized process conditions were as follows, feeding pressure 55.48 kPa, backwash pressure 9.79 kPa, and underflow pressure 31.94 kPa. Under these conditions, the average hematite ore classification efficiency of coarse fraction (-2~+0.15mm), medium fraction (-0.15~+0.074mm) and fine fraction (-0.074mm) were 85.08%, 65.10% and 51.41%, respectively, and the relative errors with the predicted values were 1.6%, 4.0% and 2.5%, respectively. The results showed that the analytical model has good predictive performance. This research provides a certain prospect for the application of Cyclonic Continuous Centrifugal Separation to hematite ore classification. it provides a reference for the application of the Response Surface Methodology in the classification of hematite by Cyclonic Continuous Centrifugal Separation.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 1; art. no. 158864
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
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