Research On The Technology Of Removing Lead From Recycled Copper Smelting

Copper has excellent regenerative capacity,and can be repeatedly reused.Low self-sufficiency of coppper is a larger gap compared with the developed countries,a serious shortage of copper resources is one of the main factors in China’s copper smelting and processing industry.Therefore,Metal regeneration recycling can realize "resources-products-consumption-renewable resources",in line with the new industrialization development direction.In this paper,we study how to eliminate lead in the scrap copper.By thermodynamic analysis shows between 1357～1509K,PbO and Pb generating Cu2O,PbO and SiO2 slagging,Jremoval of lead standard Gibbs free energy are negative.Proving that in the melting temperature of 1403～1473K,lead impurity element can be removed.Therefore,choose the Cu2O as oxidant;SiO2 as the refining agent.Three different surface morphology of SiO2 were researched in the laboratory experiments.with dense micro porous structure of 3#SiO2 have the best effects to eliminate lead.Lead content reduces from 0.5%to 0.210%,the rate of decline is 58%.Sodium carbonate,silica sand and boron oxide melt oxidation refining and coal-radicle are used in the industrial test.Compared the different waste copper content of Pb and researched he content of Cu2O and oxidation slag time on the effect of removing impurity.It shows that:Lead content reduces from 0.143%to 0.115%,the rate of decline is 19.6%.Oxidizing agent reaction time have little effect on lead removal.Increased antioxidant agent can improve the effect of lead removal.Lead content reduces from 0.0067%to 0.0050%,the rate of decline is 25%,reaching T2 ordinary copper on lead content requirements.Industrial testing process after dusting refining process,the oxygen content are not more than 0.03%in the melt,to industrial requirements.When oxygen content is 339.37ppm,then the highest conductivity reachs 96.78%IACS.