Mining waste waters

Clevenger T.E. Use of sequential extraction to evaluate the heavy metals in mining wastes. Water Air Soil Pollut 1990 50 241-254. 

Air oxidation layers on arsenopyrite are much thinner than layers produced from oxidizing mine waste-waters (Nesbitt and Muir, 1998, 141). The air-oxidized layers also contain Fe(III) hydroxides, Fe(III) arsenates, and Fe(III) arsenites, which are noticeably different than the Fe(III) oxyhydroxides that form in water-oxidized layers (Nesbitt and Muir, 1998, 141). An arsenopyrite sample from the Halen Mine of Wawa, Ontario, Canada, oxidized in air during 25 years of storage at the University of Western Ontario. The Fe As ratio of the arsenopyrite surfaces increased from 1 0.93 to 1 12.1 during the 25 years of air oxidation. Nesbitt and Muir (1998, 141-142) concluded that the increased ratio resulted from As(0) diffusing from the interior of the sample to its surfaces and oxidizing to As(III) and As(V). 

Nesbitt, H.W. and Muir, IJ. (1998) Oxidation states and speciation of secondary products on pyrite and arsenopyrite reacted with mine waste waters and air. Mineralogy and Petrology, 62, 123-44. 

Benes P, Sebesta F, Sedlacek J, et al. 1983. Particulate forms of radium and barium in uranium mine waste waters and receiving river waters. Water Res 17 619-624. 

Jenke DR, Diebold FE. Electroprecipitation treatment of acid mine waste-water. Water Res 1984 18 855-859. 

An investigation of the surface composition and chemical state of three naturally weathered arsenopyrite samples exposed for periods ranging from 14 d to 25 yr showed that the arsenopyrite surface has an effective passivating layer that protects the mineral from further oxidation (Nesbitt and Muir, 1998). The same samples were then reacted with mine-waste waters, which caused extensive leaching of the arsenopyrite surface below the oxidized overlayers. The acidic nature of the solution caused dissolution of the previously accumulated ferric arsenite and arsenate salts. 

Schuegerl, K., Mohrmann, A., Gutknecht, W., and Hauertmann, H., Application of liquid membrane emulsion for recovery of metals from mining waste waters and zinc liquors. Desalination, 1985, 53 197-215. 

Derivation (1) Leaching of bauxite with caustic soda followed by precipitation of a hydrated aluminum oxide by hydrolysis and seeding of the solution. The alumina hydrate is then washed, filtered, and calcined to remove water and obtain the anhydrous oxide. (2) Aluminum sulfate from coal mine waste-waters is reduced to alumina. 

HPLC has also been applied to the analysis of trimethylolpropane and pentaerythritols in industrial synthesis solutions, 2-mercaptobenzothiazole in waste dump effluent, polythionates in mining waste water, isocyanates in working atmospheres, carcinogenic amines, aniline in waste water, polyethylene oxide fatty acid surfactants in industrial process waters and phthalate esters in river water. 

Shao, E., Wei, J., Yo, A., Levy, R. (2009). Apphcahon of ultrafiltration and reverse osmosis for mine waste water reuse. In Water in mining conference, Perth, 15 — 17 September Available from http //www.nirosoft.com/files/CollahausiChileMiningEffluents(l).pdf. Accessed January 2014. 

Kalin, M., Wheeler, W.N. Meinrath, G. (2005) The removal of uranium from mining waste water using algaEmiorobial biomass. Journal of Environmental Radioactivity, 78, 151-177. 

In Chapter 23, Nilsen et al. describe the field testing of an emulsion liquid membrane system for copper recovery from mine solutions. The small, pilot plant-scale, continuous circuit for the recovery of copper from mine waste waters and low-grade leach solutions was field tested at a copper mine. Formulation of the emulsion membranes was optimized to provide emulsions with good stability during extraction, but which could be easily broken in an electrical coalescer under mild conditions. Typical results from the tests were >90 percent copper recovery, while maintaining the membrane swelling in the range of 4-8 percent. Cost evaluations indicate the potential for cost-effective recovery of copper from such solutions. 

In fact, electrochemical methods and electrochemical reactors have to be developed in order to resolve many problems in different area (mining, waste water treatment etc). 

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