Two-stage biological dump leaching method of secondary copper sulphide ore

Abstract

Method for two-stage bioleaching of secondary copper sulfide ore, comprising the following steps: 1) feeding secondary copper sulfide ore, after crushing, to a leach pad to build a heap and performing the first stage of leaching, until 40% to 50% copper is leached from the last layer of ore, wherein the concentration of sulfuric acid in a spray solution is greater than or equal to 20 g / L, and the concentration of Fe3+ is greater than or equal to 15 g / L; 2) performing the second stage of leaching on the secondary copper sulfide ore leached from the first stage of leaching in step 1), using a 1.2<pH<1.5 spray solution, and when the temperature of the leached solution is lower than 45°C, reducing spray intensity; 3) a mixed leachate from the first stage of leaching and the second stage of leaching undergoing extraction, stripping, and electrodeposition to obtain cathodic copper. The technique of the method is simple, its process parameters are easy to control, the method effectively facilitates leaching of secondary copper sulfide ore, and significantly lowers the leached copper slag grade, effectively improving overall resource utilization.

Description

technical field [0001] The invention relates to the field of hydrometallurgy, in particular to a two-stage bioheap leaching method for secondary copper sulfide ores. Background technique [0002] At present, nearly 20 mines in the world have used the bioheap leaching-extraction-electrodeposition process to treat secondary copper sulfide ore. It has a history of industrialization for nearly 30 years, showing significant advantages such as low cost and low energy consumption. It has become a The preferred process for secondary copper sulfide ore; my country's first 10,000-ton biological copper extraction mine was put into production at Zijinshan Copper Mine at the end of 2005. It not only utilizes low-grade resources that are difficult to utilize by traditional processes, but also obtains good economic benefits. This technology started from the TL process developed and applied in Chile in the 1980s. The characteristics of this process include agglomerate, acid aging and thin la...

AI Technical Summary

Problems solved by technology

This technology started from the TL process developed and applied in Chile in the 1980s. The characteristics of this process include agglomerate, acid aging and thin layer heap leaching, etc.; the leaching process uses lower acidity (pH=1.8) and high iron concentration ( 2~3g / L), resulting in the inability of the first-stage leaching of chalcocite to be efficient; the use of single-layer heap leaching cannot utilize the heat released by the oxidation of sulfide in the ore, resulting in a low temperature of the ore heap. The second stage of chalcocite is different from other Leaching of refractory copper minerals cannot be performed efficiently

At present, most of the secondary copper sulfide bioheap leaching mines that have been put into production in the world follow the Chilean TL process, which generally has prominent problems such as low leaching efficiency, long leaching cycle and high-grade leaching residue. To achieve 80% copper leaching rate requires leaching for 12-18 month

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