Study On Recovery Of Platinum From Spent Oil Catalysts

Platinum is a kind of versatile metal with high catalytic activity and chemical stability.It is widely used in industry,and the platinum market demand is growing as modern as today,as a result the recovery becomes important.At present,platinum has been widely used inpetrochemical engineering as a main catalys,which should be replaced at regular intervals because of carbon deposit or poisoning.So the spent catalysts has became the important secondary resources as a kind of secondary resource.In this paper,recycling technology was studied with spent catalysts worked as a kind of raw material,proposing a pre-processing chloridize leaching and resin adsorption process program,which can realize recycling platinum efficiently.The results show that the optimum calcination temperature of the pretreatment is 400?,and the pretreatment of the waste catalyst is not needed.In the study of chlorination leaching process,single-factor and comparison experiment of chlorination leaching were carried out under the conditions of HCl-H2SO4-NaClO3,HCl-H2O2 and HCl-NaClO3.The results show that Pt leaching efficiency was lower than the other two systems under the condition of HCl-H2SO4-NaClO3,and the defferency between HCl-H2O2 and HCl-NaClO3 almost do not exist.HCl-NaClO3 was chosen as finial system,as NaClO3 is difficult to volatilize under high temperature which is much cheaper than H2O2.The optional leaching condition was:temperature of 90?,liquid-solid ratio of 4:1,time of 2h,HCl concentration of 6molL-1,acidity of lmol·L-1 and at this condition Pt leaching efficiency was 97.8%.And the efficiency in industry was determined by circulating leaching experiments.The results showed that Pt content keep same in secondary residue,and the leaching efficiency was 95.7%?In the study of resin adsorption and desorption process process,the results showed that resin adsorption optional condition was temperature of 60?,time of 8 min,acidity of 1mol·L-l,and at the condition Pt adsorption efficiency was 99.2%.The desorption optional condition was temperature of 95?,time of 5h,NaOH concerntration of 1.2 mol·L-1,and at the condition Pt desorption efficiency was 98.9%.