Method for preparing biological flocculant by using biological iron-calcium slag in heap biological leaching

Abstract

The invention discloses a method for preparing a biological flocculant by using biological iron-calcium slag in heap biological leaching. Iron in the biological iron-calcium slag is leached and concentrated by using the biological iron-calcium slag generated in a low-grade copper ore hydrometallurgy heap biological leaching process. The method includes the following three main steps: (1) pre-separation of iron and calcium: mixing the biological iron-calcium slag with raffinate in proportion to obtain iron-rich raffinate, and then adding limestone for neutralization to obtain biological iron-rich slag; (2) multi-stage countercurrent leaching: carrying out circulating countercurrent leaching on the biological iron-rich slag in the system through two-stage serial leaching tanks; and (3) colloid destabilization and separation: sequentially carrying out ultrasonic destabilization and high-temperature viscosity reduction on the mixed solution, and then carrying out filter pressing to obtain the biological flocculant. The production cost is low, the iron concentration in the leachate is larger than 100 g / L, the flocculant can be used as a biological flocculant, the problem of accumulation of biological iron-calcium residues of enterprises is solved, the environmental protection risk and pressure are reduced, and meanwhile economic benefits are created for the enterprises.

Description

technical field [0001] The invention relates to the technical field of post-treatment of hydrometallurgy, in particular to a method for synthesizing a biological flocculant by utilizing biological iron-calcium slag resources generated in a copper sulfide ore biological wet heap leaching system. Background technique [0002] There are at least 360 kinds of copper-containing minerals in nature, and these copper minerals can be divided into copper sulfide minerals and copper oxide minerals. The copper minerals in my country are mainly sulfide ores. Among the proven reserves, sulfide ore accounts for only 97%, oxidized ore stands for 10%, and mixed ore only accounts for 3%. [0003] The grade of copper sulfide mineral is relatively low, which is not suitable for traditional copper smelting technology. Therefore, "biological heap leaching-solvent extraction-electrodeposition" has quickly become the preferred process for low-grade secondary copper sulfide ores, relying on its ad...

AI Technical Summary

Problems solved by technology

[0006] The cost of permanent heap leaching is low and the leaching rate is high, but it will cause uncontrollable oxidation of pyrite in the old heap in the lower layer, and the concentration of iron and acid in the leachate and raffinate will continue to increase, resulting in increased environmental neutralization costs

At the same time, the high concentration of iron and acid will make it difficult for microorganisms in the system to survive and reproduce, resulting in a decrease in leaching speed and leaching rate

In addition, the iron concentration in the raffinate is generally 50-70g / L, which fails to meet the standard of bioflocculants, and contains more impurities, and the use area is narrow

[0007] At present, the method of controlling iron and acid concentration in the system in production is to use part of the raffinate for lime neutralization or use limestone to neutralize the raffinate and then return to the storage yard for spraying. This method can better control the acid and acid concentration in the system. Iron concentration, but will produce a large amount of biological iron-calcium slag, need to build a special slag storage

And the amount of slag will continue to increase with time, causing greater environmental and social pressure

At present, there is no suitable solution for this biological iron-calcium slag. Therefore, the resource recycling of this iron-calcium slag can provide a new idea to solve this environmental risk

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