Method for comprehensively recovering valuable metal from copper smelting ash

Abstract

The invention discloses a method for comprehensively recovering valuable metal from copper smelting ash. Firstly, a magnetic separation method is adopted to primarily separate the copper smelting ashto obtain iron-enriched ash and low-iron ash; the iron-enriched ash is leached by sulfuric acid to obtain iron-enriched slag and copper sulfate solution; the low-iron ash is neutrally leached to obtain neutral leaching slag and neutral leaching liquid; the neutral leaching slag is leached by low-acid liquid to obtain high-lead bismuth slag and acid leaching liquid; the acid leaching liquid is neutrally leached again; the neutral leaching liquid is reduced by SO2 to obtain As2O3 and copper sulfate solution; and the copper sulfate solution is electrodeposited to obtain pure copper. The magneticseparation pretreatment method is adopted to separate black substances which are about 20% of the total quantity of the ash and contain a lot of iron and less copper, so that the neutral leaching treatment quantity is reduced, the arsenic content of the neutral leaching liquid is increased, the SO2 reduction arsenic sinking is facilitated, meanwhile, the influence of iron on the acid leaching filtration is reduced, the acidity of acid leaching can be greatly improved, the arsenic content in the acid leaching slag is reduced, iron-enriched slag, high-lead bismuth slag and high-purity copper areobtained, and comprehensive recovery of the valuable metal is realized.

Description

technical field [0001] The invention relates to a comprehensive treatment method for solid waste in the smelting process of nonferrous metals, in particular to a method for comprehensively recovering valuable metals from copper smelting soot in combination with separation and smelting. Background technique [0002] A large amount of soot produced in the process of copper smelting contains Cu, Fe, As, Pb, Zn, Bi and other valuable metals, the grade is higher than that of ordinary ores, and has high comprehensive utilization value. has been widely concerned. Common methods include alkaline leaching, acid leaching, and combined fire and wet methods. [0003] Since most of the soot returns to the smelting system during the copper smelting process, the outflow is only considered when the Pb and As are high, so the outflow is small, which is suitable for the wet treatment process. Among them, the sulfuric acid leaching method is the most widely used. Hou Xingang et al. (Experime...

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Problems solved by technology

Zhang Xiaofeng et al. (The effect of roasting on the leaching rate of copper in high-arsenic white soot and its thermodynamic analysis. Mining and Metallurgy Engineering, 2012, 32(5):86-89.) studied the thermodynamics of white soot roasting transition-acid leaching, and the results showed that, Roasting can convert insoluble copper sulfide and cuprous oxide into soluble copper, greatly improving the copper leaching rate, which explains the reason why the copper leaching rate is not high in the direct acid leaching process, but there is arsenic in the roasting transformation process. Volatile behavior, not conducive to environmental protection

Patent applications 200910080464.7, 201410690393.3, 201510693277.1, 201610030159.7, etc. disclose methods for leaching copper soot with sulfuric acid system, all of which achieve good leaching of valuable elements, but these methods have long process flow, low concentration of leachate, and easy to produce "three wastes". "

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