Study On The Technology And Mechanism Of Ultrasonic-enhanced Zinc Leaching Residue To Extract Lead

Lead is widely used in batteries,cable jackets,machinery manufacturing,shipbuilding,light industry,lead oxide,and radiation protection,and its position in the construction of the national economy is becoming increasingly important.C hina is the world's largest producer of lead.Due to the shortage of lead mineral resources,low grade,and complex composition,the shortage of lead metal supply is becoming increasingly severe,and the self-sufficiency rate is declining.If only relying on lead ore smelting can no longer meet the needs of industrialization,and its production and application are more and more restricted due to the toxicity of lead,the production of lead is gradually shift ing to the recycling of secondary resources.Leaching residue of zinc is an important secondary resource containing lead,and its recycling value is increasingly prominent.Leaching lead refining can avoid the discharge of lead-containing flue gas and sulfur dioxide,solve the pollution of lead-containing flue gas,and realize the clean treatment and recycling of lead-containing materials.However,conventional leaching has high energy consumption,long process flow and low efficiency and other process problems,and a new method of ultrasonically strengthened leaching lead has been proposed.The wet extraction process and theoretical study of zinc leaching residues are carried out by means of condition experiment,kinetic analysis,orthogonal experiment,etc.The solid-liquid composition,physical phase and morphology were characterized,revealing the mechanism of ultrasonically enhanced wet leaching.The main research conclusions are as follows:(1)The optimized process parameters of conventional leaching are:two-stage leaching,reaction time of 120min,calcium chloride concentration of 350 g/L,liquid-solid ratio of 6:1,reaction temperature of 45?,p H value is 2 and the leaching rate of Pb is 85.67%.(2)The optimized process parameters of ultrasonic enhanced leaching are:one-stage leaching,reaction time is 100min,calcium chloride concentra tion is 350g/L,liquid-solid ratio is 5:1,reaction temperature is 35?,leaching agent p H is 3,The leaching rate of Pb was 88.65%.Ultrasonic enhanced leaching can shorten the reaction time,simplify the leaching process,reduce the liquid-solid ratio,and make the reaction conditions mild.(3)In the process of leaching lead with calcium chloride,the two most critical factors affecting the leaching rate are the liquid-solid ratio and the calcium chloride concentration.The liquid-solid ratio can change the mass transfer rate and diffusion rate of the substance in the reaction process,thereby affecting the leaching rate of the leaching process;changes in the concentration of calcium chloride will affect the solubility of the product lead chloride in calcium chloride,affecting the leaching reaction speed.(4)The leaching process of lead in the HCl-CaCl₂ system is a liquid-solid two-phase chemical reaction.Increasing the leaching temperature and reducing the particle size are beneficial to increase the leaching rate.In the experiment,the apparent activation energies of the nuclear dynamic model under conventional and ultrasonic conditions were 20.06 k J/mol and 7.56 k J/mol,respectively.In summary,a new method of ultrasonically enhanced wet smelting lead for the process problems of conventional lead leaching such as high energy consumption and low efficiency was proposed,which forms an efficient,fast and green extraction of lea d in zinc leaching slag.A new way to deal with the efficient utilization of secondary resources containing lead was provided,and a reference for the development of new processes was provided.