Heap bioleaching method for secondary copper sulfide ore

Abstract

The invention discloses a heap bioleaching method for secondary copper sulfide ore. The heap bioleaching method for the secondary copper sulfide ore comprises the steps that after the secondary copper sulfide ore is heaped, mine acid waste water or raffinate is used for spray wetting and fungus distribution, so that microorganisms are made to grow rapidly on the surface of the ore, and rapid leaching of the secondary copper sulfide ore is achieved; and afterwards, the leaching process is conducted by two stages, specifically, in the first stage, the raffinate obtained after leach liquor is extracted is used for continuous spraying, the acid concentration is controlled to 5-15 g / L, the total iron concentration is controlled to 5-15 g / L, and the oxidation reduction potential does not need to be controlled particularly; and the second stage is started when the copper leaching rate reaches 45%-50%, the mine acid waste water or the mixed liquor of the mine acid waste water and the raffinate is used for intermittent spraying in the second stage of the leaching process, the acid concentration is controlled to 3-6 g / L, the total iron concentration is controlled to 3-6 g / L, and the oxidation reduction potential is controlled to 600-700 mV. By adoption of the heap bioleaching method for the secondary copper sulfide ore, oxidation of iron pyrite can be effectively restrained while efficient leaching of copper is achieved, technological parameters can be controlled easily, the production cost is low, and the economic benefit and the environment benefit are remarkable.

Description

technical field [0001] The invention relates to the field of hydrometallurgy, in particular to a method for biological heap leaching of secondary copper sulfide ores. Background technique [0002] The "biological heap leaching-extraction-electrodeposition" process has significant advantages such as low cost and low energy consumption, and has become the preferred process for low-grade secondary copper sulfide ores. At present, nearly 20 mines around the world use this process. my country's first 10,000-ton biological copper extraction mine was put into production at Zijinshan Copper Mine at the end of 2005. This method makes full use of low-grade resources that are difficult to use by traditional techniques and obtains good economic benefits. During the process, the oxidation of pyrite in the ore has not been effectively controlled, which gradually increases the leaching amount of acid and iron, resulting in an increasing cost of environmental protection and neutralization. ...

AI Technical Summary

Problems solved by technology

my country's first 10,000-ton biological copper extraction mine was put into production at Zijinshan Copper Mine at the end of 2005. This method makes full use of low-grade resources that are difficult to use by traditional techniques and obtains good economic benefits. During the process, the oxidation of pyrite in the ore has not been effectively controlled, which gradually increases the leaching amount of acid and iron, resulting in an increasing cost of environmental protection and neutralization

[0004] Among the above four patent documents, the first three did not fully consider the leaching characteristics of secondary copper sulfide ore, and the entire leaching process adopts the same control process, which cannot take into account the efficient leaching of copper and the inhibition of pyrite oxidation; in addition, the first two patents The literature must periodically add special bacteria solution, and the raffinate of the first patent needs to be neutralized with limestone and lime before returning to spraying, all of which will increase the production cost virtually; in addition, the third patent controls The total sulfate concentration is too high for use in industrial production

Although the fourth patent considers the leaching characteristics of secondary copper sulfide ores, the acid and iron concentrations in the first stage of the leaching process are too high, and when the acid and iron concentrations of the leaching solution are too high, even after mixing with the second stage leaching solution It also cannot meet the requirements of the copper extraction process, and the acid and iron concentrations in the first leaching process are far greater than those of the raffinate, so it is necessary to add sulfuric acid and iron salts in the production process to achieve the required process Requirements, which will greatly increase production costs; the second leaching process only controls pH 1.2 to 1.5, does not mention the control of redox potential and iron concentration, and cannot achieve a good effect of inhibiting pyrite oxidation

Images