URANIUM AND MOLYBDENUM LEACHING FROM THE ORE OF "VOSTOK" DEPOSIT

Agitation leaching of uranium and molybdenum from the ore of “Vostok” deposit (Kazahstan) containing 0.285 % of uranium and 0.035 % of molybdenum was performed. Sulfuric acid solutions (of 1 to 3 %) as well as solutions containing oxidants, ferric sulfate and ammonium persulfate, were used as leach solutions. Also, the sample of acid mine drainage collected at “Vostok” deposit containing ferric iron ions and cells of acidophilic microorganisms was used for the leaching. Leaching with sulfuric acid solutions made it possible to leach no more than 19.4 and 24.4% of uranium and molybdenum, respectively. Oxidants allowed to increase extraction of metals. The leaching with ferric sulfate made it possible to extract up to 68 and 28.2 % of uranium and molybdenum, respectively. The leaching with ammonium persulfate made it possible up to 95.2 and 34.8 % of uranium and molybdenum, respectively. High extent of metal extraction was reached when using the sample of acid mine drainage: 95 % of uranium and 48.6 % of molybdenum were extracted. Thus, it was shown that acid mine drainage, which are formed due to complex biogeochemical processes in ore dumps and during ore dressing wastes storage may be successfully used as leach solutions for oxidative leaching of metals from uranium ores.

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Uranium Bioleaching from Low Grade Ore

Materials Science Forum ◽

10.4028/www.scientific.net/msf.989.559 ◽

2020 ◽

Vol 989 ◽

pp. 559-563

Author(s):

Ashimkhan T. Kanayev ◽

Khussain Valiyev ◽

Aleksandr Bulaev

Keyword(s):

Sulfuric Acid ◽

Acid Mine Drainage ◽

Mine Drainage ◽

Sulfuric Acid Concentration ◽

Acid Leaching ◽

Leach Solution ◽

Low Grade ◽

Bacterial Cells ◽

Acid Mine

The goal of the present work was to perform bioleaching of uranium from low grade ore from Vostok deposit (Republic of Kazakhstan), which was previously subjected to long-term acid leaching. The ore initially contained from 0.15 to 0.20% of uranium in the form of uraninite, but ore samples used in the study contained about 0.05% of uranium, as it was exhausted during acid leaching, and uranium was partially leached. Representative samples of ore were processed in 1 m columns, leach solutions containing 5, 10, 20 g/L of sulfuric acid and bacterial cells (about 104) were percolated through the ore. Leaching was performed at ambient temperature for 70 days. In one of the percolators, the leaching was performed with leaching solution containing 10 g/L of H2SO4, cells of A. ferrooxidans, and 0.5 g/L of formaldehyde. Leaching with the solution containing 5, 10, and 20 g/L of sulfuric acid made it possible to extract 50, 53, and 58% of uranium. Addition of formaldehyde in leach solution led to the decrease in uranium extraction extent down to 37%. Thus, the results of the present work demonstrated that uranium ore exhausted during long-term acid leaching may be successfully subjected to bioleaching, that allows extracting residual quantities of uranium. Leaching rate of uranium from exhausted ore depended on both sulfuric acid concentration and microbial activity of bacteria isolated from acid mine drainage, formed on uranium deposit. In the same time, acid mine drainage may be used as a source of inoculate, to start bioleaching process.

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The Effect of Different Oxidants on Extraction of Uranium from Low Grade Ore

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.299.1104 ◽

2020 ◽

Vol 299 ◽

pp. 1104-1108

Author(s):

Ashimkhan T. Kanayev ◽

Khussain Valiyev ◽

Aleksandr Bulaev

Keyword(s):

Sulfuric Acid ◽

Potassium Permanganate ◽

Ferric Sulfate ◽

Low Grade ◽

Acid Solutions ◽

Uranium Recovery ◽

Ammonium Persulphate ◽

Uranium Extraction ◽

Increase Rate ◽

Sulfuric Acid Solutions

The effect of different oxidants on extraction of uranium from low grade ore was studied. Leaching was performed using sulfuric acid solutions at a concentration of 10 to 30%. Ferric sulfate Fe2(SO4)3, ammonium persulphate (NH4)2S2O8, and potassium permanganate KMnO4 at different concentrations were used as oxidants in different variants of the experiment. In addition, solutions collected at Vostok deposit containing 6.86 g/L Fe3+ and 106 cells/mL of the bacteria Acidithiobacillusferrooxidans were used for leaching. The rate of uranium extraction with sulfuric acid solutions without oxidants was low and did not exceed 19.4%. Addition of oxidants made it possible to increase rate of uranium extraction. In the presence of ferric sulfate, ammonium persulphate, and potassium permanganate rates of uranium extraction were up to 68, 95.2, and 69.6%, respectively. The rate of uranium leaching in the experiments with the AMD sample was high and reached about 95%. Therefore, it can be concluded that using not only oxidizing agents, but AMD, which are formed during the natural oxidation of sulfide minerals contained in the ore of the deposit, can significantly increase the rate of uranium recovery.

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Treatment of Copper-Containing Acid Mine Drainage by Neutralization-Adsorption Process Using Calcite as Neutralizer and Polyhydroxamic Acid Resin as Adsorbent

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.161.200 ◽

2012 ◽

Vol 161 ◽

pp. 200-204 ◽

Cited By ~ 2

Author(s):

Shuai Wang ◽

Gang Zhao ◽

Zhong Nan Wang ◽

Qian Zhang ◽

Hong Zhong

Keyword(s):

Sulfuric Acid ◽

Acid Mine Drainage ◽

Acid Solution ◽

Sulfuric Acid Solution ◽

Adsorption Process ◽

Mine Drainage ◽

Acid Mine ◽

Adsorption Capacities ◽

Adsorption And Desorption Performance ◽

Almost All

Acid solution and copper-containing acid mine drainage (AMD) was treated by neutralization-adsorption process. The results showed that pH can be adjusted to 4.0 by adding 10g·L-1calcite in acid solution with pH=1.0. Adsorption and desorption performance of poly(hydroxamic acid) (PHA) resin for Cu2+and Fe3+ions were investigated by column tests. The results showed that adsorption capacities of PHA for Cu2+and Fe3+ions were satisfying, and the metals adsorbed on PHA can be eluted by sulfuric acid solution effectively. AMD of Dexing copper mine of Jiangxi was treated as a sample. The results showed that 1.5g·L-1calcite can remove almost all of the Fe3+ion, and Cu2+ion can be removed by PHA and then be eluted by sulfuric acid solution with adsorption ratio of 98.95% and elution ratio of 98.50%, separately.

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