Research On The Recovery Of Copper And Iron From The Reduction Of Copper Slag By Aluminum Electrolysis Waste Cathode Carbon Block

Copper slag is a byproduct of produced by copper smelting industry,which contains rich valuable metal resources,of which iron content is more than 40%and copper content is about 1%.Most of the copper slag is stored in slag yard,which not only occupies land but also pollutes the environment,and is not effectively used.Therefore,it is very important to carry out the research on the recovery and utilization of copper and iron resources with copper slag as raw material.At the same time,it is noted that a large number of waste cathode carbon blocks will be produced in the electrolytic aluminum industry every year,which contains 60-70%carbon content and30-40%electrolyte.It is a recyclable secondary resource,but it contains a large amount of soluble fluoride and a small amount of cyanide,which is listed as hazardous solid waste by the state.Due to the high cost of treatment,enterprises mainly use the method of burning or burying,resulting in serious environmental pollution and resource waste.Based on the basic composition of waste cathode carbon block,a new method of recovering copper and iron resources from copper slag by using waste cathode carbon block produced by aluminum electrolysis is proposed.First of all,the experimental study of copper recovery from converter copper slag was carried out by using waste cathode carbon block.The research results show that the copper content in the final slag can be reduced from 5.71%to 0.45%by adding 2.8%waste cathode carbon,3.4%silicon dioxide,injecting 300 ml/min nitrogen for 20 minutes and settling for 60 minutes at 1300?.At the same time,96.6%of the F from waste cathode carbon is fixed in the final slag,and the leachable F^-in the final slag detected by ion chromatography is only 4.32 mg/L,which is far lower than the national allowed emission standard(100 mg/L).While recovering copper resources in the copper slag,the harmless and resourceful of waste cathode carbon is realized.Secondly,the recovery of iron resources from furnace copper slag by smelting reduction was studied with waste cathode carbon block.The research results show that the lowest S content(0.03wt.%)metal iron block can be obtained at 1450?by adding 14.4%waste cathode carbon and 25%CaO into copper slag after oxidative desulphurization in air atmosphere.The recoveries of copper and iron in copper slag are 95.89%and 94.64%respectively,and more than 90%of fluoride from waste cathode carbon is transferred to the final slag in the form of CaF₂ and Ca₂Si₂F₂O₇.In addition,the value of leachable F^-in the final slag by ion chromatography is3.11mg/L,which is far lower than the national allowable emission concentration in China.While recycling the iron resources in the copper slag,the harmless and resourceful of waste cathode carbon is realized.