Temat: Leaching - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: A study on heavy metals mobility from zinc plant residues in Iran
Autorzy:: Moradkhani, D.
Eskandari, S.
Sedaghat, B.
Najafabadi, M. R.
Tematy:: heavy metals
zinc leaching plant
leaching filter cake
column leaching; Pokaż więcej
Data publikacji:: 2013
Powiązania:: https://bibliotekanauki.pl/articles/110826.pdf Link otwiera się w nowym oknie
Źródło:: Physicochemical Problems of Mineral Processing; 2013, 49, 2; 567-574
1643-1049
2084-4735
Pojawia się w:: Physicochemical Problems of Mineral Processing
Opis:: The transport of heavy metals from mining disposal site to groundwater and surface water is one of the most serious environmental problems in the world. The transport of heavy metals such as Zn, Cd and Mn from leaching filter cake in RECo, Zanjan, Iran was examined by using column leaching. Parameters studied included: flow rate, pH of input solution and leaching time. In this study, the maximum dissolution percents of Zn, Cd and Mn in input solution pH of 5 were 45.50 %, 53.97% and 19.94%, respectively. To statistically analysis the experimental results, SPSS14 software was employed. The results of SPSS 14 indicated that for the Zn, Cd and Mn dissolution, time and flow rate were found respectively, the effective parameters for the pollution in zinc leach residues.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Removal of calcium from magnesite flotation concentrate by selective leaching and kinetics analysis
Autorzy:: Hu, Xiaoxing
Zhu, Yangge
Tematy:: selective leaching
magnesite
dolomite
leaching kinetics; Pokaż więcej
Data publikacji:: 2020
Powiązania:: https://bibliotekanauki.pl/articles/1845225.pdf Link otwiera się w nowym oknie
Źródło:: Physicochemical Problems of Mineral Processing; 2020, 56, 5; 939-948
1643-1049
2084-4735
Pojawia się w:: Physicochemical Problems of Mineral Processing
Opis:: Dolomite is the main impurity mineral in magnesite ore, affecting the quality of magnesite products. This study proposed a selective leaching process to reduce the calcium content from the magnesite flotation concentrate using hydrochloride acid (HCl). Laboratory scale tests were conducted to explore the influence of operation factors including HCl concentration, leaching temperature and time, stirring speed on the leaching recovery. The results showed that leaching recovery of CaO and MgO increased with increasing HCl concentration, temperature and time. The CaO leaching recovery is always significantly higher than that of MgO, indicating a good selectivity of HCl to leach dolomite from magnesite. The leaching kinetics of both dolomite and magnesite follow the Avrami model and are diffusion controlled, with an activation energy of 43±}1 kJ×mol-1 and 25±}4 kJ×mol-1, respectively.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Basic theory and optimization of gold containing antimony concentrate leaching by alkaline sulfide
Autorzy:: Wu, Hao
Feng, Yali
Li, Haoran
Liao, Shengde
Wang, Hongjun
Tematy:: antimony concentrate
leaching process
alkaline leaching
kinetics; Pokaż więcej
Data publikacji:: 2019
Powiązania:: https://bibliotekanauki.pl/articles/109524.pdf Link otwiera się w nowym oknie
Źródło:: Physicochemical Problems of Mineral Processing; 2019, 55, 1; 248-257
1643-1049
2084-4735
Pojawia się w:: Physicochemical Problems of Mineral Processing
Opis:: As sodium sulfide is easily oxidized to polysulfide and thiosulfate which have a gold leaching effect, gold would dissolve in leaching solution when extracting stibium from gold containing antimony concentrate by alkaline sulfide. Through leaching test and kinetics analysis, the decomposition regularity of sodium sulfide and leaching rate were studied under different leaching conditions. The results indicated that the gold content in antimony concentrate was 28.41g/Mg, and the content of antimony and sulfur was 36.01% and 14.04%, respectively. The main metallic minerals were native gold, arsenopyrite, stibnite, and the gangue minerals were mainly quartz. Anodic polarization curve shows reduced iron powder can increase the peak potential of the oxidation of the leaching solution and it can effectively prevent the decomposition of sodium sulfide and the dissolution of gold. Optimized stibium-extraction efficiency was achieved under the following conditions: a concentration of sodium sulfide and sodium hydroxide at 110g/dm³ and 20g/dm³, respectively; a ratio of iron powder to concentrate of 1:30; a ratio of liquid to solid of 5:1; agitation speed of 600rad/min; reaction temperature of 353.15K; and a reaction time of 3 h. Under the optimized conditions, high antimony recovery (97.35%) and low gold dissolution (1.32%) were achieved.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Kinetics study and reaction mechanism for titanium dissolution from rutile ores and concentrates using sulfuric acid solutions
Autorzy:: Ismael, Mohamed H.
Mohammed, Hesham S.
El Hussaini, Omneya M.
El-Shahat, Mohamed F.
Tematy:: leaching kinetics
leaching mechanism
titanium
rutile concentrate
leaching design
shrinking
core model; Pokaż więcej
Data publikacji:: 2022
Powiązania:: https://bibliotekanauki.pl/articles/2146851.pdf Link otwiera się w nowym oknie
Źródło:: Physicochemical Problems of Mineral Processing; 2022, 58, 1; 138--148
1643-1049
2084-4735
Pojawia się w:: Physicochemical Problems of Mineral Processing
Opis:: Recent developments of acid leaching of titanium concentrates and ores have produced renewed industrial and commercial interest. However, the leaching kinetics and mechanism of these concentrates and ores had received little attention. This work, therefore, addresses the leaching kinetics and mechanism of Ti from a rutile concentrate in sulfuric acid solution. The leaching reaction was controlled by diverse parameters like temperature, particle size, acid concentration, liquid/solid (L/S) ratio, and stirring speed. The leaching kinetics was investigated using the Shrinking Core Model in order to determine the optimum criteria which control the reaction. The kinetics analysis showed that the rate of dissolution of Ti increased by increasing reaction temperature, L/S ratio, and stirring speed, while it decreased upon increasing particle size. The kinetics analysis revealed that the dissolution reaction is controlled by the chemical reaction at the rutile particle surface. Applying the Arrhenius relation, the apparent energy of activation Ea for the leaching reaction was calculated to be 23.4kJ/mol. A semi-empirical overall rate equation was introduced to describe the combined effects of the process variables upon the rate of the dissolution reaction: 〖1-(1-x)〗^(1/3)=k_0 〖 C〗_([H2SO4])^0.803 〖 (dp)〗^(-0.518) 〖(L/S)〗^0.793 〖(w)〗^0.668 e^((-23400/RT)) t
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: The effect of nut shell addition on the permeability of a crushed gold ore
Autorzy:: Yilmaz, S.
Sirkeci, A. A.
Bilen, M.
Yigit, I.
Kizgut, S.
Tematy:: permeability
nut shells
heap leaching
gold leaching
leach efficiency; Pokaż więcej
Data publikacji:: 2018
Powiązania:: https://bibliotekanauki.pl/articles/110544.pdf Link otwiera się w nowym oknie
Źródło:: Physicochemical Problems of Mineral Processing; 2018, 54, 2; 467-475
1643-1049
2084-4735
Pojawia się w:: Physicochemical Problems of Mineral Processing
Opis:: In this study, variations in permeability of a gold ore by nut shell addition was studied. Ore particle size, nut shell size and volume fraction in the ore were the parameters investigated. Permeability is an important issue in heap leach operations considering the processing duration. Particularly below 6 mm particle size permeability is greatly hampered. Turkey is the leading country in the world in hazelnut production. Therefore, considerable amounts of nut shell are obtained as a by-product. Incerase in the permeability of a finely crushed ore will obviously enable an increase in the leaching efficiency. The finer the particle size the more the liberation of gold is yet the permeability is lower. Therefore, this study focuses on the possibility of improving the permeability of ore heaps with nut shell addition. Optimum amount of nut shell which should be added to the ore was found to be 5% by volume. It was found that the permeability of ore crushed below 2.36 mm considerably increased by the addition of nut shell below 18 mm.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Zinc extraction from Ghazouat leach residues by using jarosite method
Autorzy:: Begar, Abdelhakim
Djeghlal, Mohamed El Amine
Ould Hamou, Malek
Tematy:: sphalerite
Zn
zinc
acid leaching
leaching residue
extraction; Pokaż więcej
Data publikacji:: 2021
Powiązania:: https://bibliotekanauki.pl/articles/2016450.pdf Link otwiera się w nowym oknie
Źródło:: Mining Science; 2021, 28; 117-126
2300-9586
2353-5423
Pojawia się w:: Mining Science
Opis:: In this paper, it was aimed to select and propose a feasible as well as an applicable method, for the extraction of zinc that was present in the disposed GHAZOUAT leach residues having 17.82 wt. % Zn and 20.82 wt. % Fe. After the determination of the components of the residue, the acid leaching was performed to reclaim Zn sequentially. The acid leaching experiments were carried out for Zn extraction by controlling acid concentration, reaction duration and temperature. At the optimum conditions, 240 g/L H2SO4 at 90 °C for 210 min, 80% of initial iron content was removed, and the resultant overall zinc extraction was usually superior than 96%.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Chloride leaching of silver and lead from a solid residue after atmospheric leaching of flotation copper concentrates
Autorzy:: Chmielewski, T.
Gibas, K.
Borowski, K.
Adamski, Z.
Wozniak, B.
Muszer, A,
Tematy:: copper concentrate
atmospheric leaching
chloride leaching
silver
lead; Pokaż więcej
Data publikacji:: 2017
Powiązania:: https://bibliotekanauki.pl/articles/109629.pdf Link otwiera się w nowym oknie
Źródło:: Physicochemical Problems of Mineral Processing; 2017, 53, 2; 893-907
1643-1049
2084-4735
Pojawia się w:: Physicochemical Problems of Mineral Processing
Opis:: Recovery of silver and lead by means of chloride leaching of solid residue after atmospheric leaching of the copper concentrate from Lubin Concentrator (KGHM) was investigated. The effect of leaching temperature, chloride concentration, Fe(III) and oxygen presence, solid-to-liquid ratio and feed preleaching with NaOH on the silver and lead recovery was analyzed. Chloride leaching appeared to be very effective for recovery of lead, whereas satisfactory recovery of silver was observed after chemical pretreatment of the leaching feed with alkali solution of NaOH in order to liberate Ag entrapped in the jarosite structure. It was found that to achieve the satisfactory recovery of Ag and Pb leaching had to be performed in acidified 4 M chloride concentration at temperature of 90 oC. The presence of oxidants, that is O2 and iron(III) ions, was beneficial in the initial stage of the process. The maximum recovery of Ag and Pb was found for the solid-to-liquid ratio of 1:10 after 10 hours leaching.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Ługowanie miedzi i cyny z odpadów elektronicznych za pomocą bakterii Acidithiobacillus ferrooxidans
Leaching of copper and tin from electronic waste using Acidithiobacillus ferrooxidans
Autorzy:: Blazek, V.
Zavada, J.
Bouchal, T.
Lebr, J.
Fecko, P.
Tematy:: odpad elektroniczny
ługowanie bakteryjne
Acidithiobacillus ferrooxidans
electronic waste
leaching
bacterial leaching; Pokaż więcej
Data publikacji:: 2012
Powiązania:: https://bibliotekanauki.pl/articles/318276.pdf Link otwiera się w nowym oknie
Źródło:: Inżynieria Mineralna; 2012, R. 13, nr 1, 1; 1-7
1640-4920
Pojawia się w:: Inżynieria Mineralna
Opis:: Określono efekt ługowania metali z odpadów elektronicznych przy użyciu bakterii Acidithiobacillus ferrooxidans w warunkach statycznych. Zbadano ługowanie miedzi i cyny z płytki drukowanej układu elektronicznego i porównano do ługowania chemicznego. Całkowita ilość usuniętych metali była nieco mniejsza we wszystkich przypadkach. Dodatek bakterii ulepszył proces ługowania miedzi, jednak porównywalne rezultaty otrzymano poprzez dodanie mineralnej pożywki nie zawierającej bakterii. Ługowanie cyny przebiegało w inny sposób, a obecność bakterii nie polepszyła wydajności procesu.
This contribution is focused on the leaching of metals from electronic waste using bacterium Acidithiobacillus ferrooxidans under static conditions. Leaching of copper and tin from circuit board using bacteria was verified and compared to chemical leaching. The overall amounts of leached metals were quite low in all variants. Addition of bacteria improved the leaching of copper; however comparable results were obtained by addition of the sole nutrient medium without bacteria. Leaching of the tin followed different pattern and was not improved by presence of bacteria.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Effect of externally adding pyrite and electrical current on galvanic leaching of chalcopyrite concentrate
Autorzy:: Asgari, Kaveh
Hassanzadeh, Ahmad
Nazari, Sabereh
Vakylabad, Ali Behrad
Hosseinzadeh, Mostafa
Tematy:: copper concentrate
galvanic leaching
pyrite
electrical current
leaching kinetics; Pokaż więcej
Data publikacji:: 2021
Powiązania:: https://bibliotekanauki.pl/articles/1447957.pdf Link otwiera się w nowym oknie
Źródło:: Physicochemical Problems of Mineral Processing; 2021, 57, 2; 105-119
1643-1049
2084-4735
Pojawia się w:: Physicochemical Problems of Mineral Processing
Opis:: Although the operating properties of GalvanoxTM leaching have been widely studied in the literature, several factors concerning chalcopyrite passivation during the process remain unknown so far. The present work hence aims at investigating the significant effect of externally added pyrite features with a particular focus on its particle size (d80 of 0.52, 20, 45 and 2000 µm) through a series of experiments performed in a 2-L stirred-tank electro-reactor. To this end, the role of pyrite: chalcopyrite ratio (0.49:1, 2:1 and 4:1) and presence of electrical current were examined while the rest of the parameters kept constant (80 °C temperature, 400–500 mV (Ag/AgCl) redox potential, pulp density of 10% (w/v), and stirring rate of 1200 rpm). Plus, kinetic models of the leaching tests were studied based on the diffusion and chemical controlling concepts. It was found that the coarser the pyrite particles, the more favorable the copper extraction from the concentrate due to acceleration of reactions in the cathodic electrode and high mass transfers. However, this was in contradiction with the existing reports in the literature. Moreover, galvanic interactions became intensive in the presence of pyrite meaning extensive chalcopyrite dissolution with significantly reduced passivation. Ultimate copper extraction values of 24.17±1.25%, 55.79±0.91% and 57.26±1.59% were resulted at Py:Cp ratios of 0.49:1 (natural), 2:1 and 4:1, respectively. The results showed that maximum copper recovery of 67.32±2.34% was obtained at an optimum condition of pyrite grain size=2000 µm, Py:Cp=4:1, current application=500 mA, 8 h and 80 °C. Finally, detailed kinetic modeling indicated that the chemical control mechanism was dominant in the early reaction stages (tt>3.5 h) was controlled by the diffusion control.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Hydrometallurgical removal of uranium and thorium from Ethiopian tantalite ore
Autorzy:: Cheru, Mulugeta Sisay
Albertodel Rosario, Alberto Velázquez
Yimam, Abubeker
Tadesse, Bogale
Berhe, Gebreyohannes Goitom
Tematy:: leaching
tantalite
uranium
thorium; Pokaż więcej
Data publikacji:: 2019
Powiązania:: https://bibliotekanauki.pl/articles/110542.pdf Link otwiera się w nowym oknie
Źródło:: Physicochemical Problems of Mineral Processing; 2019, 55, 2; 448-457
1643-1049
2084-4735
Pojawia się w:: Physicochemical Problems of Mineral Processing
Opis:: This study focused on the leaching of uranium and thorium from a high grade Ethiopian tantalite ore using sulfuric acid. The effects of variables such as acid concentration, temperature and leaching time were studied. In general, the leaching efficiency of uranium increases with increasing temperature from 100 to 300°C whereas the opposite trend was observed for thorium. The amount of uranium leached increased from 69.1% at contact time of 1 hr to 88.6% when the tantalite ore was leached for 3 hrs. On the other hand, for the experiments conditions considered in this study, the leaching behavior of uranium and thorium did not change significantly with varying sulphuric acid concentration from 70 to 90 wt%. Overall, the highest dissolution of uranium and thorium were achieved at 100°C, 70 wt% H2SO4 concentration and 1 hr contact time.
Dostawca treści:: Biblioteka Nauki

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