Tailings Gold Recovery by Cyanide Leaching from Future Ores
[Thesis]
Medina, Diego
Anderson, Corby
Colorado School of Mines
2020
128 p.
M.S.
Colorado School of Mines
2020
Mining Negotiation Santa Maria de la Paz, S.A. of C.V. (NEMISA) has operated the Cobriza and Dolores copper mines in Villa de la Paz, San Luis Potosi, Mexico for more than 150 years. The copper mineral values occur primarily as chalcopyrite and bornite along with a minor secondary sulfide mineralization. Also, there are ores that contain significant gold and silver values, these ores are processed through the beneficiation plant with a rate of 8,500 ton per day using a flotation concentrator. Gold and silver values not recovered in the copper flotation concentrate report to the tailing storage facilities (TSF). Commonly, flotation tailings contain 0.5-0.7 g/ton of gold and about 15 g/ton of silver respectively. However, different methods have been investigated for recovering the values of gold and silver currently being lost to the TSF. In addition, NEMISA has performed metallurgical evaluations for improving the flotation technologies and implementing cyanidation of the flotation tailings. These evaluations have shown that the current flotation tailings have shown that 70-75% of the gold and 15% of the silver contained in the TSF can be recovered by conventional cyanidation. NEMISA is evaluating the feasibility of installing a cyanidation circuit to recover these values of gold and silver. However, there are not metallurgical studies for futures ores to be mined, thus this thesis will explain the practices, processes and metallurgical results for future ores.