Ultrasonic Enhanced Removal Of Arsenic Impurities In The Sewage Acid Of Lead Smelting System Experiment And Mechanism Research

At present,non-ferrous metal smelting enterprises generally uses smelting flue gas containing SO₂ to produce sulfuric acid for recycling and reduce the SO₂ content in the flue gas.In the process of sulfuric acid production,a large amount of waste acid containing harmful impurities is produced,called waste acid.The waste acid contains a large amount of free acid and high concentration of harmful elements,if directly discharged without treatment,it is easy to cause great harm to the environment and human health.This paper takes the high arsenic contaminated waste acid produced from the lead smelting system of a lead-zinc smelting enterprise in Yunnan and take it as the research object,a new process of remove arsenic by combining lead powder and CuSO₄ is proposed.The effects of conventional conditions and ultrasonic strengthening conditions on the arsenic removal are studied,and the reaction mechanism of arsenic removal is studied.The main research work is summarized as follows:1)In this paper,the arsenic removalc by combination of CuSO₄ and zero-valent lead under conventional conditions and the arsenic removalc by combination of CuSO₄ and zero-valent lead under ultrasonic conditions are determined.Lead and CuSO₄ are used as the additive reagent for arsenic removal.The single factor experiment of molar ratio of Pb to As,CuSO₄ concentration,reaction temperature,reaction time and ultrasonic power is carried out systematically.The influence of different factors on the arsenic removal effect are explored,and the optimal process conditions of conventional process and ultrasonic strengthening process are obtained.Through comparison,it is find that the ultrasonic strengthening process has the advantages of small reagent addition,high arsenic removal efficiency and short reaction time.2)Through thermodynamic analysis to study the relationship between chemical reaction?G and temperature T in the reaction system,to judge the feasibility of the chemical reaction in the arsenic removal reaction system,and based on this theory the follow-up mechanism research is carried out.Through the analysis methods of XRD,SEM and XPS,the microstructure of the arsenic-containing precipitate is analyzed and detected,the transformation method of areenic and copper in the waste acid is ascertained,and the reaction mechanism between the conventional process and the ultrasonic strengthening process is revealed.3)Carry out kinetic experiments of conventional process and the ultrasonic strengthening process,use the unreacted strinking reaction core model to fit the experimental results of the two processes,obtain the apparent activation energy and control steps of conventional process and ultrasonic strengthening.The kinetic equations are obtained separately,and the kinetic results provide a theoretical basis for increasing the arsenic removal rate.