Deep Removal Of Arsenic And Antimony By Crude Copper Fire Method

Copper is an important metal,which is widely used in electrical,electronic,light industry,transportation,machinery manufacturing,telecommunications,military industry and other industries.However,in the process of copper smelting,arsenic and antimony are difficult impurity elements in copper,accompanied by the whole process of copper smelting.If the output of blister copper arsenic antimony is too high,there will have a lot of adverse effects in the process of copper electrolysis,such as causing anode passivation,floating anode slime,etc.Therefore,how to remove arsenic from crude copper in the process of fire refining has become the focus of current research.In this paper,two kinds of slag-forming agents,sodium carbonate and borax,were used to study the effect of melting temperature,the amount of slagging agent and holding time on the removal of arsenic and antimony in blister copper through the existing equipment in the laboratory,and was also detected in crude copper S,O,Ni content changes,explored the effect of mixed use of two kinds of slagging agent at the end of the experiment.Through the analysis of the experimental data of the composition of copper alloy after smelting,the results are as follows:(1)In the experiment of using sodium carbonate as slagging agent,when the amount of sodium carbonate added is 4.5%of blister copper quality,the melting temperature is 1270? and the holding time is 20 minutes,the removal of arsenic and Sb can reach the best removal effect.At this time,the removal rate of arsenic is 99%,the removal rate of Sb is 98%and the arsenic content in blister copper can be removed from 0.157%to 0.001%,the Sb content in blister copper can be removed from 0.068%to 0.001%.The addition of sodium carbonate enables the deep removal of arsenic and antimony in blister copper.(2)In the experiment of using borax as slagging agent,when the amount of borax added is 5%of blister copper quality,the melting temperature is 1270? and the holding time is 540 minutes,the removal of arsenic and antimony can reach the best removal effect.At this time,the removal rate of arsenic is 86%,the removal rate of antimony is 88%,the arsenic content in blister copper can be removed from 0.106%to 0.024%,and the antimony content in blister copper can be removed from 0.051%to 0.011%.The addition of borax can not make the arsenic and antimony in the crude copper reach deep removal.(3)By comparing two kinds of slagging agents of sodium carbonate and borax,it can be found that when the slagging agent is sodium carbonate,the removing effect of arsenic in blister copper is better than the removing effect of antimony,and the removal of arsenic and antimony is mainly rely on the their pentavalent oxide and sodium carbonate slagging to remove;However,when the slagging agent is borax,the result is opposite,the removal effect of antimony in blister copper is better than arsenic.According to this,we conjectured that after adding borax in blister copper,the arsenic and antimony in blister copper are mainly removed by oxidation to As2O3 and Sb2O3,and the volatility of Sb2O3 is better than that of As2O3.(4)Under the test conditions of arsenic and antimony removal from sodium carbonate,the content of nickel in the copper remained at 0.163%before and after smelting,and sodium carbonate had almost no effect on the removal of nickel.The sulfur in the blister copper was reduced from 0.011%to below 0.004%.(5)In the experiment of removing arsenic and antimony from borax,when the borax was added in an amount of 5%,the melting temperature was 1270?,and the holding time was 420 minutes,the maximum removal rate of nickel in blister copper could reach 75%.The nickel content in blister copper from 0.159%down to 0.067%.The removal effect of borax on sulfur is not as good as sodium carbonate.(6)In the experiment of mixed flux of borax and sodium carbonate to remove arsenic and antimony,the removal rate of arsenic and antimony decreases with the increase of R(mass ratio of borax and sodium carbonate),when the R is equal to 1/3,the removal rate of arsenic and antimony could reach the maximum.At this time,the removal rate of arsenic is 94%,which could remove the content of arsenic in the blister copper from 0.103%down to 0.007%;The removal rate of antimony can reach 78%,which could remove the content of antimony in the blister copper from 0.040%down to 0.010%.Compared with the experiment of using sodium carbonate as slagging agent,the addition of borax is not conducive to the removal of arsenic and antimony.