The Research Of The Separation Between Aluminum And Plastic In Scraps Of Plastic Containing Aluminum

The solid waste is one of the most dramatic increased waste in urban waste.Because most of waste is resourcable and at the time harmful,it is very essential to start on the studying of separation and recovery of solide waste with regard to both environment protection and reuse of resources.This paper has studied the separation between Aluminum and plastic in scraps of plastic containing Aluminum with the method of hydrometallurical leaching.We has evoluated various factors,such as dosage,temperature,time,and solid:liquid ratio on the separation of Al-plastic compound material.The results of pill tablets shows 100 precent leaching yield when the concentration of hydroxide acid 2mol/1,leaching time 4h,leaching temperature 40℃,the ratio of 15:1.aluminum and PVC were completely separated when Sodium hydroxide 1.25mol/l,leaching time 20min, leaching temperature 70℃,the ratio of 15:1.The relevance degree of the three factors are concentration,temperature,time.concentration,extraction time and temperature leaching aluminum leaching of importance were: sodium hydroxide concentration,leaching temperature,the extraction time. Under the best conditions for leaching acid leaching system 2mol/l concentration of hydrochloric acid leaching temperature of 40℃,the extraction time is 4 hours,liquid-to-solid ratio 15:1.In these conditions, the leaching rate of 100%aluminum,the aluminum and aluminum-plastics plastics separation from the film.In these conditions, aluminum and PVC complete separation.Leaching results of PC disc showed that the leaching yield of Al is 67%under the conditions of hydroxide acid 2.5 mol/l,temperature 50℃,leaching time 4h,the ratio of liqud to solid 10:1 and particle range of 3mm～6mm.While the leaching yield of Al is 76%,when the feed is in the particle range of 2mm～3mm.Under the conditions of sodium hydroxide 2.5 mol/l,temperature 70℃,leaching time 70min,the ratio of liqud to solid 10:1 and particle range of 3mm～6mm,the leaching yield is 55%.The relevance degree of the three factors are concentration,temperature,time.And it can be see from the experiment that in alkaline conditions,the leaching rate si high while the errosion of the equipment is relatively low.In condition with the data,the leaching kinetics of Al has proposed: in acidic and alkaline conditions,leaching process of pill tablets were controled by surface chemical reaction,while leaching temperature and acidity are the main factors.In acidic conditions,leaching process of PC disk was also controled by surface chemical reaction,while alkaline condition,the procss is controlled by diffusion leaching temperature and agitotaing rate are the main factors.So it is safe to say that it's praticable to use hydrochloric acid and sodium hydroxide as the lixivium to separate Al from plastic.The reagent used is nontoxic,cheap and easy to get.The waste can be recycled,to be discharge safely to reach a double win of envioroment protection and economic benificts.