| Annotation |
During gold heap leaching, cyanide-bearing wastes (process solution and stockpiled heap leach wastes) are formed. Their detoxification period is unlimited. In this connection, in order to solve environmental issues, biopassive detoxication method is of great interest. It is based on a spontaneous decomposition of cyanides under the influence of natural factors including the activity of autochthonous bacterial community and, thus, the use of toxic chemical reagents is excluded. In order to model the cyanide-bearing gold heap leach wastes passive detoxification process, long-term experiments on the ore mass storage under the conditions of the ore heap zoning were carried out. It was found that biochemical processes prevail over simple chemical oxidation in the course of passive detoxification. Approximating equations for the major toxic compounds biodegradation (thiocyanates and cyanides including copper and nickel cyanide complexes) were calculated. They predicted the length of biopassive detoxification at an industrial site of a deposit from the Republic of Sakha (Yakutia). The developed technology allows the optimization of water balance and use of evaporation method for the excess of water from spent process solutions without their discharge to the environment as well as the decrease in the concentration of cyanides (from 81,62 mg/L, down to 0,05 mg/L), thiocyanates (from 21,4 mg/L, down to 0,17 mg/L), copper and nickel (from 21,32 mg/L and 0,5 mg/L, to less than 0,05 mg/L and 0,03 mg/L, respectively) in the ore heap. The developed flow sheet and equipment scheme of the process propose the elimination of reagents and use of the infrastructure available at the site. This allows the reduction of capital and operational costs compared to conventional chemical detoxification technology. The expected economic result from using the developed technology was 151429,7 roubles |
| References |
1. Emeliyanov Yu.E., Shketova L.E., Gudkov S.S., Kopylova N.V., Verhozina V.A. Gorny zhurnal (Mining Journal), 2012, no. 8, pp. 108—111.
2. Petrov V.F., Petrov S.V. Zolotodobycha (Gold mining), 2012, no. 164. Available at: http://www. zolotodb.ru/artides/technical/10699 (Date of access: 23.10.2017).
3. Declercq J., Tait D., Bowell R. Proceedings IMWA 2016 (Proceedings IMWA 2016). Freiberg, Germany, 2016, pp. 417—424.
4. Huddy R.J., Zyl A.W., Hille R.P., Harrison S.T.L. Minerals Engineering (Minerals Engineering), 2015, vol. 76, pp. 65—71.
5. Kandasamy S., Dananjeyan B., Krishnamurthy K., Benckiser G. Brazilian Journal of Microbiology (Brazilian Journal of Microbiology), 2015, vol. 46, no. 3, pp. 659—666.
6. Kantor R.S., Zyl A.W., Hille R.P., Thomas B.C., Harrison S.T.L., Banfield J. Environmental Microbiology (Environmental Microbiology), 2015, vol. 17, no. 12, pp. 4929—4941.
7. Karamba K.I., Syed M.A., Shukor M.Y., Ahmad S.A., Karamba K.I. Journal of Environmental Microbiology and Toxicology (Journal of Environmental Microbiology and Toxicology), 2014, vol. 2, no. 2, pp. 58—60.
8. Kumar V., Kumar V., Bhalla T.C. Microbial and Biochemical Technology (Microbial and Biochemical Technology), 2015, vol. 7, no. 6, pp. 344—350.
9. Mirizadeh S., Yaghmaei S., Ghobadi N.Z. Journal of Environmental Health Science and Engineering (Journal of Environmental Health Science and Engineering), 2014, vol. 12, no. 85, pp. 1—9.
10. Ndur S.A., Doe J.M., Asiam E.K. Research Journal of Environmental and Earth Sciences (Research Journal of Environmental and Earth Sciences), 2015, vol. 7, no. 2, pp. 24—28.
11. Parmar P., Soni A., Vyas K., Desai P.V. International Journal of Environmental Sciences (International Journal of Environmental Sciences), 2012, vol. 2, no. 4, pp. 2006—2014.
12. Singh N., Agarwal B., Majumder C.B. Journal of Engineering Research and Applications (Journal of Engineering Research and Applications), 2014, vol. 4, no. 3, pp. 827—831. |
