Study On The Process Of Selenium Evaporation From Copper Anode Mud Under Unconventional Condition

In view of the disadvantages of heavy pollution and high energy consumption of traditional copper anode slime sulfated roasted selenium,this paper studies the process of sulfated roasted and steamed selenium under unconventional conditions,and obtains the better experimental conditions and kinetic rules of roasted and steamed selenium process,which provides a theoretical basis for optimizing the industrial production of sulfated roasted steamed selenium under unconventional conditions.On the basis of thermodynamic and kinetic analysis,copper anode slime of removing arsenic and antimony was used as raw material to study the effects and kinetics of roasting temperature,acid-ore ratio and roasting time on the effect of sulfated roasting and evaporating selenium were investigated under unconventional conditions.（1）The experiment of selenium evaporation by sulfating roasting of copper anode slime under rough vacuum showed that with increasing ratio of acid to ore,improving roasting temperature and prolonging roasting time and reducing chamber pressure could improve the evaporation ratio of selenium.Under the optimum conditions of chamber pressure 55k Pa,ratio of acid to ore 0.75,roasting temperature 673K,roasting time 15min,the evaporation ratio of selenium was 96.48%,the selenium content in distilled residue was 0.19%.The process of selenium evaporation was controlled by chemical reaction and the apparent activation energy of evaporation selenium in vacuum was calculated as 43.604 k J/mol by Arrhenius formula.（2）The experiment of selenium evaporation by sulfating roasting of copper anode slime by microwave heating in air showed that prolonging the roasting time,increasing the roasting temperature and ratio of acid to ore were beneficial to improve the volatilization ratio of selenium.Under the optimum conditions of microwave heating power 500W,air flow of200L/h,roasting temperature 823K,roasting time 45min and ratio of acid to ore 0.85,the evaporation ratio of selenium was 96.83%,the selenium content in distilled residue was 0.17%.The process of selenium evaporation was controlled by chemical reaction and the apparent activation energy of evaporation selenium was 43.604k J/mol.（3）The experiment of selenium evaporation by sulfating roasting of copper anode slime by microwave heating in oxygen-enriched air showed that prolonging the roasting time,increasing the roasting temperature and acid-ore ratio could improve the evaporation ratio of selenium.The amount of sulfuric acid could be reduced by sulfating roasting with oxygen-enriched air.Under the optimum conditions of microwave heating power 500W,oxygen-enriched air of 39.23%O₂flow of 200L/h,roasting temperature 823K,roasting time45min and ratio of acid to ore 0.75,the evaporation ratio of selenium was 96.67%,the selenium content in distilled residue was 0.18%.The process of selenium evaporation was controlled by chemical reaction and the apparent activation energy of evaporation selenium was 42.329k J/mol.