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%.