Papers by Keyword: Dump Leaching

Abstract: The characteristics of Yangla copper oxide ore and acid leaching of this copper ore were investigated. The results indicate direct dump acid leaching of raw ore is not feasible for the treatment of this copper ore in practice. Sieve sizing-warming-stirring-acid leaching process was employed for the treatment of the fine grain materials below 1m, while 66.19% copper leaching efficiency and10.92 t H2SO4 consumption for per ton are obtained. Dump acid leaching process was employed for the treatment of the coarse grain materials above 1 mm, while 68.65% copper leaching efficiency and 15.43 t H2SO4 consumption for per ton copper are obtained. Key techniques are that sieve sizing process strictly controls the content of fine grain materials in dump leaching process and the searches ability of H2SO4 for the internal copper ore is improved, while warming-stirring-acid leaching process reinforces the copper leaching efficiency of fine grain materials. The proposed in this paper will be of benefit to the utilization of similar refractory copper oxide ore with high content of slime and iron minerals.

Abstract: A dump located in the proximity of the Vlaikov Vrah mine, Bulgaria, and containing about 120 000 tons of run-of-mine mining wastes (low-grade ores and rock mass), since 1968 was subjected initially to spontaneous natural bioleaching based on the rains as irrigating leach solutions, then from 1972 to 2003 to commercial-scale bioleaching by means of irrigation with acidified leach solutions, and since 2004- again to spontaneous natural bioleaching. The monitoring of these processes during this 40-year period revealed considerable changes in the composition, geotechnical and acid-base properties of the dump material, as well as in the diversity, number and activity of its microflora.The data obtained during this study were used to stimulate the bioleaching process in the huge commercial-scale copper dump leaching operation at Vlaikov Vrah mine in which about forty million tons of such mining wastes were treated.

Abstract: Los Bronces has two ROM dump leach operations called Leach I and Leach II. Leach I was commissioned in 1998 and currently produces 12,700 ton per year. The copper mineralization in these dumps is largely sulfides, namely 60% chalcocite/covellite, 30% chalcopyrite and the balance is oxides. The Leach II plant, commissioned in early 2002, was built to treat around 700 million ton of marginal ore having 0.45% total copper. The copper mineralogy of this material is estimated to be 70% chalcopyrite, 20% chalcocite/covellite and the balance oxides. Current copper production is 33,700 ton per year. Early in 2004 it was decided to conduct a complete column test work program, aimed at reducing power, acid and lime consumption at the Leach II plant. The results of this work, partially reported at IBS 2005, have been successfully applied to the commercial operation since the end of 2005. As a consequence, the projected reduction in operating costs for 2006 of US$ 5.5 million was accomplished. The main results of the column test work program, the modifications implemented together with the results obtained at the operation, including a molecular characterization of the microbial population, are discussed in this paper.