pH variation mechanism of high sulfur-containing bauxite

Abstract

In order to fundamentally solve the acidification problem of high sulfur-containing bauxite during storage, by simulating the environment of minerals storage in laboratory, the acidification mechanism and influencing factors of high sulfur-containing bauxite were studied and confirmed using the single variable method to control the atmosphere, water and other variables. The results show that the acidification is mostly caused by the oxidation of sulfur-containing bauxite, which is mainly the natural oxidation of Pyrite (FeS₂), then the alkaline minerals dissolute in the presence of water, leading to the acidification phenomenon, which is influenced by moisture and air flow. Finally, more acid-producing substances are formed, resulting in the acidification of high sulfur-containing bauxite. The acidification of high sulfur-containing bauxite results from the combined effect of the oxygen in the air and water, which can be significantly alleviated by controlling the diffusion of the oxygen in air.

Keywords

high sulfur-containing bauxite / pyrite / acidification mechanism

References

[1] CuiP-p, HuangZ-m, ZhouS-lian. Overview of bauxite resources in China [J]. Light Metals, 2008, 2: 6-8

[2] SunZ-w, LuA-li. Status quo and issue and countermeasures of bauxite exploitation in our country [J]. China Mining Magazine, 2008, 17(5): 13-15

[3] LiC-f, WangA-j, ChenX-j, ChenQ-s, ZhangY-f, LiYing. Regional distribution and sustainable development strategy of mineral resources in China [J]. Chinese Geogrhical Science, 2013, 23(4): 470-481

[4] LiX-b, LiC-y, QiT-gui. Reaction behavior of pyrite during Bayer digestion at high temperature [J]. The Chinese Journal of Nonferrous Metals, 2013, 23(3): 829-835

[5] ChenM-h, ZhuR, LiW-bin. The research on desulfurization mechanism of high sulfur bauxite [J]. Light Metals, 2012, 7: 7-9

[6] FuS-wei. Prospection analysis of development of high-sulfur bauxite of Guizhou [J]. Mineral Exploration, 2011, 2(2): 159-164

[7] YangQ-p, LüX-cui. The industrial practice of producing metallurgical grade alumina from high sulfur bauxite [J]. Light Metals, 2012, 7: 10-12

[8] RaymundH J. Acid mine drainage [J]. Industrial and Engineering Chemistry, 1947, 39(5): 642-646

[9] AkcilA, KoldasS. Acid mine drainage (AMD): Causes, treatment and case studies [J]. Journal of Cleaner Production, 2006, 14: 1139-1145

[10] YangZ-xi. The factor and prevention of acid waste water in the mining area [J]. World Mining Express, 1999, 15(10): 42-45

[11] LiangGang. Harms and treatment techniques of nonferrous metal mining wastewater [J]. Metal Mine, 2010, 12: 158-161

[12] BylinaI V, MojumdarS C, PapangelakisV G. Effect of storage time on the pressure oxidation enthalpy of pyrite [J]. Journal of Thermal Analysis and Calorimetry, 2012, 108(3): 829-835

[13] MitsuoM. Comparison of rates of pyrite oxidation by dissolved oxygen in aqueous solution and in compacted bentonite [J]. Journal of Mineralogical and Petrological Sciences, 2009, 104(2): 59-68

[14] WeiD W, OsseoasareK. Semiconductor electrochemistry of particulate pyrite mechanisms and products of dissolution [J]. Journal of the Electrochemical Society, 1997, 144(2): 546-553

[15] FredericD, MartineM, BernardH. Pyrite oxidation in acidic medium: Overall reaction pathway [J]. Surface and Interface Analysis, 2008, 40: 343-348

[16] ZhangN-b, LiZ-y, GuoP-li. Desulfurization mechanism and application of high sulfur bauxite [J]. Metalurgia International, 2013, 18(3): 29-32

[17] ChandraA P, GersonA R. The mechanisms of pyrite oxidation and leaching: A fundamental perspective [J]. Surface Science Reports, 2013, 65(9): 293-315

[18] HolmesP R, CrundwellF K. The kinetics of the oxidation of pyrite by ferric ions and dissolved oxygen [J]. Geochim Cosmochim Acta, 2000, 64(2): 263-274