Copper slag melting oxidation chlorination-reduction method for recovering copper and producing qualified molten iron

Abstract

The invention provides a method for recycling copper and preparing qualified molten iron by carrying out smelting, oxidation and chlorination-reduction on copper slag. The method comprises the following steps of: warming the copper slag discharged at high temperature, adding a chlorinating agent and additive, after the copper slag is fully molten, introducing oxide gas into the copper slag, and carrying out oxidation chlorination desulphurization decoppering to obtain molten liquid; carrying out stepped cooling on high-temperature smoke formed during oxidation chlorination desulphurization decoppering and then recycling copper in the smoke; under the inert gas atmosphere, introducing powdered coal to cause the powdered coal to be mixed with the slag under the stirring action of inert gas and be subjected to melting reduction reaction, and standing until the slag and molten iron are separated, thereby obtaining high-temperature qualified molten iron. By applying the method provided by the invention, the defect that sulphur content and copper content in the molten iron in the traditional copper slag direct melting reduction ironmaking process are high can be effectively overcome, and high-efficiency recycling of copper resource in the copper slag is realized, thus the method provided by the invention has better industrialization prospect.

Description

Technical field [0001] The invention relates to a method for melting, oxidizing, chlorinating, and reducing hot copper slag to recover copper and preparing qualified molten iron, which belongs to the field of resources and environment. Background technique [0002] In recent years, China's iron and steel industry has developed rapidly, and its position in the world's iron and steel industry is very important. For more than a decade, the total amount of steel production has been the first in the world. However, the status of iron ore resources in my country is far from meeting the needs of the steel industry, and the domestic iron ore resource distribution has the defects of more lean ore and multi-element intergrowth compound ore, lack of iron ore resources, and low grade. In addition to the huge production capacity of national steel companies, the increasing demand for iron ore, and the dependence on imports, under the economic background of soaring iron ore prices, the cost of i...

AI Technical Summary

Problems solved by technology

Relevant literature proves, reclaims iron in copper slag by this method, can make the enrichment degree of iron in magnetite in slag reach more than 85%, but this kind of method has the following disadvantages: the one is that the magnetite phase is precipitated in a large amount in the later stage of oxidation reaction, The viscosity and melting point of the slag increase, which hinders the reaction from proceeding and the magnetite phase aggregates and grows, resulting in a low iron yield; the second is that the iron resources in the copper slag are enriched by magnetic separation, and then used as ironmaking raw materials for reduction and treatment. The process is complicated; the third is that the copper slag is cooled and then fused and oxidized at high temperature, which causes waste of heat in the process

[0007] Second, adopt stage grinding stage separation process, this method has the disadvantage of low iron recovery rate in slag (less than 60%), the reason is that the magnetic iron oxide content in slag iron-containing phase is less, only 20-30%, mainly The iron-containing phase iron silicate enters the tailings during the magnetic separation process;

However, this process has the disadvantage of high content of copper and sulfur in molten iron obtained after copper slag smelting reduction (the average sulfur content is higher than 0.6%, and the average copper content is higher than 1%).