A method for step-by-step multi-component gas injection to realize deep depletion of copper slag

Abstract

The invention provides a method for realizing deep depletion on copper slag through multielement gas substep injection. The method fully utilizes waste heat of molten copper slag, copper matte is converted into oxide through gasification desulphurization, then selective reduction is carried out to obtain copper iron alloy with higher copper content, the problem of copper slag depletion in a smelting process is solved, and low-sulfur low-copper depletion slag is produced, so that conditions are created for a follow-up iron extracting process, and the deep depletion on the copper slag is realized; the traditional matte-producing depletion process is abandoned, but a gasification desulphurization process is firstly carried out for converting the copper matte into the oxide, then the oxide is subjected to selective reduction by virtue of a reducing agent, so that a copper-iron alloy phase is obtained. Operation is simple, adaptability is strong, the method can be realized by modifying the original electric furnace, nickel slag similar to the copper slag in properties can be treated, and metal elements such as Cu, Ni, Co and Fe can be comprehensively recycled.

Description

technical field [0001] The invention belongs to the field of metallurgy, and in particular relates to a method for realizing the deep depletion of copper slag by step-by-step injection of multi-component gases. Background technique [0002] In copper pyrometallurgical smelting, a large amount of slag is produced during both smelting and blowing. The slag contains 1% to 8% copper in the form of sulfide. Usually, mineral processing or electric furnace dilution is required to reduce the copper content in the slag. Mineral dressing dilution can reduce the copper in the slag to a minimum of 0.3%, but the infrastructure investment is large, the process is complicated, the slag needs to be cooled slowly, the heat is difficult to use, and metal elements such as Ni and Co cannot be recovered; the electric furnace dilution process is simple and heat State slag can be used directly, but the copper content of the tailing slag is usually 0.5% to 1.0%, and the copper recovery rate is low....

AI Technical Summary

Problems solved by technology

[0005] In recent years, researchers at home and abroad have conducted a lot of research on the comprehensive utilization of copper slag by reducing copper and iron, but the existing problems mainly focus on the high content of impurity elements such as sulfur and copper in the obtained molten iron, and the addition of additives CaO or CaCO3 Large, difficult separation of copper and iron, high grinding cost, etc., so far no industrial production reports

The patent application number 201010167157.5 proposes a method of producing low-sulfur molten iron by smelting and reducing copper slag, but the initial sulfur content in molten iron is high, requiring a large amount of refining desulfurization slag, and the copper in the molten iron has not been removed, so it is difficult to be used as a method for steelmaking. A large number of raw materials are used; the patent application number 201210520356.9 proposes a treatment method for waste copper slag, but the hardness of the copper slag is high, the grinding cost is high, and additional energy consumption is required for subsequent oxidation and roasting; the patent application number 201010216133.4 proposes a A method of mixing copper slag and iron ore to produce low-copper molten iron through smelting reduction, but this method is to dilute copper to reduce the copper content of molten iron, and it is difficult to use copper slag in large quantities; the patent application number 201210210648.2 proposes a reducing atmosphere kiln A method for rapidly reducing copper slag in a furnace to produce iron-copper alloys, but this process is difficult for grinding and beneficiating, and the obtained copper-iron alloy powder has a low copper content as an alloy, and the copper content exceeds the standard as a raw material for ironmaking, so the use prospect is not good; application The patent No. 201210364451.4 proposes a method for direct reduction and recovery of copper and iron from copper smelting slag, but this process uses natural gas to reduce iron in copper slag, the consumption of natural gas is large (greater than 300Nm3 / t slag), and the economic benefit is poor. It is also necessary to add a large amount of flux to adjust the alkalinity (200-300kg / t of lime slag needs to be added to maintain the alkalinity of 1.0-1.5), the production cost is high, and it is difficult to separate the reduced copper-iron alloy from the γ pig iron, and the two metals are not mentioned Effective means of phase separation

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