Oxidative leaching kinetics of molybdenum-uranium ore in H₂SO₄ using H₂O₂ as an oxidizing agent

Abstract

The processing of molybdenum-uranium ore in a sulfuric acid solution using hydrogen peroxide as an oxidant has been investigated. The leaching temperature, hydrogen peroxide concentration, sulfuric acid concentration, leaching time, particle size, liquid-to-solid ratio and agitation speed all have significant effects on the process. The optimum process operating parameters were: temperature: 95°C; H₂O₂ concentration: 0.5 M; sulfuric acid concentration: 2.5 M; time: 2 h; particle size: 74 µm, liquid-to-solid ratio: 14 ∶ 1 and agitation speed: 600 rpm. Under these experimental conditions, the extraction efficiency of molybdenum was about 98.4%, and the uranium extraction efficiency was about 98.7%.

The leaching kinetics of molybdenum showed that the reaction rate of the leaching process is controlled by the chemical reaction at the particle surface. The leaching process follows the kinetic model 1 ‒ (1‒X)^1/3 = kt with an apparent activation energy of 40.40 kJ/mole. The temperature, concentrations of H₂O₂ and H₂SO₄ and the mesh size are the main factors that influence the leaching rate. The reaction order in H₂SO₄ was 1.0012 and in H₂O₂ it was 1.2544.

Keywords

leaching of molybdenum / leaching of uranium / kinetics

References

[1] Wang M Y, Wang X W. Extraction of molybdenum and nickel from carbonaceous shale by oxidation roasting, sulphation roasting and water leaching. Hydrometallurgy, 2010, 102(1–4): 50–54

[2] Wang M Y, Wang X W, Liu W L. A novel technology of molybdenum extraction from low grade Ni-Mo ore. Hydrometallurgy, 2009, 97(1–2): 126–130

[3] Berg V D. Yang J A, Nauta M Y, Sandwijk H H K, Reuter V A. Comprehensive processing of low grade sulphidic molybdenum ores. Minerals Engineering, 2002, 15: 879–883

[4] Khoshnevisan A, Yoozbashizadeh H, Mozammel M, Sadrnezhaad S K. Kinetics of pressure oxidative leaching of molybdenite concentrate by nitric acid. Hydrometallurgy, 2012, 111–112: 52–57

[5] Amer A. Hydrometallurgical processing of low grade Qattar molybdenite concentrate, Egypt. Erzmetall. Journal for Exploration. Mining and Metallurgy, 2001, 54(7–8): 381–385

[6] Zhao Z W, Zhang G, Huo G S, Li H G. Kinetics of atmospheric leaching molybdenum from metalliferous black shales by air oxidation in alkali solution. Hydrometallurgy, 2009, 97(3–4): 233–236

[7] Vizsolyi A, Peters E. Nitric acid leaching of molybdenite concentrates. Hydrometallurgy, 1980, 6(1–2): 103–119

[8] Valenzuela F R, Andrade J P, Sapag J, Tapia C, Basualto C. The solvent extraction separation of molybdenum and copper from acid leach residual solution of chilean molybdenite concentrate. Minerals Engineering, 1995, 8(8): 893–904

[9] Medvedev A S, Aleksandrov P V. Investigations on processing low-grade molybdenum concentrate by the nitric-acid method. Russian Journal of Non-Ferrous Metals, 2009, 50(4): 353–356

[10] Warren I H, Mounsey D M. Factors influencing the selective leaching of molybdenum with sodium hypochlorite from copper/molybdenum sulphide minerals. Hydrometallurgy, 1983, 10(3): 343–357

[11] Liu Y C, Zhong H, Cao Z F. Molybdenum removal from copper ore concentrate by sodium hypochlorite leaching. Mining Science and Technology, 2011, 21: 61–64

[12] Liu W P, Xu H, Yang X Y, Shi X C. Extraction of molybdenum from low-grade Ni-Mo ore in sodium hypochlorite solution under mechanical activation. Minerals Engineering, 2011, 24(14): 1580–1585

[13] Barr D S, Lindstrom R E, Hendrix J L. Control of the chlorate factor in electrooxidation leaching of molybdenum concentrates. International Journal of Mineral Processing, 1975, 2(4): 303–320

[14] Cao Z F, Zhong H, Liu G Y, Fu J G, Wen Z Q, Wang S. Electric-oxidation extractions of molybdenite concentrate in alkaline NaCl electrolyte. Journal of CentralβSouth UniversityβofβTechnology, 2010, 17(3): 480–484

[15] Cao Z F, Zhong H, Liu G Y, Qiu Y R, Wang S. Molybdenum extraction from molybdenite concentrate in NaCl electrolyte. Journal of the Taiwan Institute of Chemical Engineers, 2010, 41(3): 338–343

[16] Landa E R. Leaching of molybdenum and arsenic from uranium ore and mill tailings. Hydrometallurgy, 1984, 13(2): 203–211

[17] Bartecki A, Rycerz L. Kinetics and mechanism of dissolution of synthetic molybdenum disulphide MoS₂ in bromate solutions. Part II: Kinetics of molybdenum disulphide dissolution in the MoS₂-KBrO₃-H₂SO₄-H₂O system. Hydrometallurgy, 1988, 20(2): 249–257

[18] Bartecki A, Rycerz L. Kinetics and mechanism of dissolution of synthetic molybdenum disulphide MoS₂ in bromate solutions. Part III: Mechanism of dissolution of molybdenum disulphide in bromate solutions. Hydrometallurgy, 1988, 20(2): 259–272

[19] Antonijevic M M, Pacovic N V. Investigation of molybdenite oxidation by sodium dichromate. Minerals Engineering, 1992, 5(2): 223–233

[20] Marczenko Z. Spectrophotometric Determination of Elements. New York: John Wiley and Sons, 1986, 107–640

[21] Welz B, Sperling M. Atomic Absorption Spectrometry. 3rd ed. New York: Wiley-VCH Weinheim, 1999, 387–500

[22] Biswas S, Pathak P N, Roy S B. Development of an extractive spectrophotometric method for estimation of uranium in ore leach solutions using 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) mixture as extractant and 2-(5-bromo-2-pyridylozo)-5-diethyl aminophenol (Br-PADAP) as chromophore. Spectrochimica Acta Part A, 2012, 91: 222–227

[23] Cotton F A, Wilkinson G. Advanced Inorganic Chemistry. 5th ed. New York: Wiley, 1988, 456–458

[24] Habashi F. Principles of Extractive Metallurgy, General Principles. Vol. 1. New York: Gordon and Breach, 1980, 111–252

[25] Ray H S. Kinetics of metallurgical reactions. New Delhi: Oxford & IBHC, 1993, 1–75

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg