【作者】 张波；

【导师】 顾帼华；

【作者基本信息】 中南大学 ， 再生材料工程， 2007， 硕士

【摘要】 固体废弃物是城市垃圾中增长最快的一类废弃物,其废弃量和积存量越来越大。大多数废弃物具有资源性和危害性的双重特点,开展有关废弃物分离回收的研究,不管是从资源再生利用的角度还是从环境保护的角度,都具有十分重要的意义。论文以工程塑料类铝塑复合材料(光盘)和通用塑料类铝塑复合材料(药片包装板)为研究对象,采用湿法浸出的工艺,进行铝塑分离研究,考察了各因素,包括浓度、温度、时间和液固比等对铝浸出过程的影响。铝塑药片包装板的浸出结果表明:在盐酸浓度2mol/L,浸出温度40℃,浸出时间4h,液固比15∶1条件下,铝的浸出率为98%。在氢氧化钠浓度1.25mol/L,浸出时间20min,浸出温度70℃,液固比15∶1条件下,铝和PVC完全分离。三因素对铝浸出过程的影响程度依次为:氢氧化钠浓度、浸出温度、浸出时间。PC光盘片的浸出结果表明:在盐酸浓度2.5mol/L,浸出温度50℃,浸出时间4h,液固比10∶1,粒度3mm～6mm条件下,铝的浸出率为67%;粒度2mm～3mm条件下,铝的浸出率为76%,细粒级的浸出效果比粗粒级的好。在氢氧化钠浓度2.5mol/L,浸出温度70℃,浸出时间20min,液固比10∶1,粒度2mm～3mm条件下,铝的浸出率达55%。三因素对铝浸出的影响程度依次为:氢氧化钠浓度、浸出温度、浸出时间。通过试验可看出,在碱性体系中,浸出速率大,浸出过程可以在比较高的温度下进行。结合试验数据,采用尝试法研究了铝的浸出机理:在酸性和碱性体系下,药片铝塑包装板中铝的浸出过程受界面化学反应控制,浓度和温度是铝浸出过程的主要影响因素。在酸性体系下,PC光盘片中铝的浸出过程也受界面化学反应控制;而在碱性体系下,铝的浸出过程则受扩散控制,浸出温度和搅拌转速对铝的浸出过程影响大。通过试验可得出结论:。采用盐酸或氢氧化钠作为浸出剂,用湿法冶金的方法浸出含铝废塑料中的铝,分离其中的铝和塑料是可行的,可达到资源再生的目的,所用试剂无毒、廉价、易得,其设备简单,反应过程中的废液经处理后,可以安全排放,改变了含铝塑料对环境的污染,从而获得环境和经济效益的统一。本研究得到了高等学校优秀青年教师教学科研奖励计划项目(2002)的资助。更多还原

【Abstract】 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.更多还原