The Reuse Of Pt/Al₂O₃ Spent Catalyst

With the continual development and progress of China's modern industry,the demand for catalyst has become increasingly urgent.In industrial production,the appropriate use of catalyst can greatly improve production efficiency and save energy.The world consumes nearly one million tons of catalyst a year,especially in petroleum and fertilizer industries.Catalysts generally contain all kinds of non-ferrous metals,In accordance with the previous methods,such as landfill,incineration and other methods to dispose of waste metal catalyst,not only waste metal resources but also cause serious environmental pollution.So effective recycling of spent catalysts is always with good economic,resources and environmental benefits.In this paper,we took extracting metal platinum from spent Pt / Al₂O₃ catalyst for petrochemical as the main line,introduced the topic background and significance of the research.Based on the needs of the research,several technologies of platinum extraction are introduced and compared.The paper describes the experimental methods and steps of the process in detail,the single factors that influence the experiment result were analyzed and compared by orthogonal experiments and verification experiment,and property of the resulting product was studied.The result of the study showed that the optimum process conditions are the spent catalyst was pulverized to 200 mesh?75?m?,after using 6mol/L sulfuric acid to dissolve the carrier,adding 0.1mol / L sodium sulfide solution was allowed to stand for 12 h,after drying and roasting,dissolved leaching residue with aqua regia,and allowed to stand for 12 h with saturated ammonium chloride solution after platinum was precipitated,washed precipitation with 10% ammonium chloride solution four times,finally after drying and roasting,the recovery rate of the platinum sponge was 98.30%,with a purity of 99.12%.Extracted sponge platinum in methane combustion reaction has good catalytic performance,conversion rate of methane reached 84%.Added an excess of concentrated aqueous ammonia to the reaction filtrate,filtered the precipitate,after washing and roasting,we get the alumina as the by-product.Alumina showed a good adsorption property in the methyl orange adsorption experiment,that can reached about 180mg/g.The study shows that extraction and separation of the Pt/Al₂O₃ spent catalyst is feasible in technology.Catalytic property of sponge platinum and adsorption property of by-product alumina have a certain economic value in application.