摘要
铑的浸出率低是回收汽车尾气废催化剂中贵金属的难题之一,贵金属铑的溶解过程主要存在的问题是:溶解周期长,溶解效率低,试剂消耗大,溶解过程复杂,浸出率低,环境污染严重等。提高汽车尾气废催化剂中铑的浸出率,并进行清洁高效提取,一直是研究重点。目前主要的溶解技术是中温氯化法和硫酸氢钠(钾)熔融法,但均不同程度的存在技术问题。本工艺采取微波焙烧回收汽车尾气废催化剂湿法浸出渣中的铑,分别考察了反应温度,反应时间和物料试剂配比3个主要因素对浸出渣中铑浸出率的影响,结果表明:微波加热有利于促进分子振动,造成颗粒破裂,增大固液反应面积,增强物质间的传热传质,增加反应速率,减小试剂消耗,能显著地提高浸出率。在最佳实验条件下:配比1∶10,反应温度600℃,反应时间1 h,铑的总体浸出率可以达到99.79%。本工艺环境污染较小,溶解效率高,且浸出率高,具有较大的发展前景,为汽车尾气废催化剂中贵金属铑的清洁高效提取提供一定的技术指导。
One of difficult problems is the low recovery of rhodium during the recovery of precious metals from spent automobile catalysts, the main problems of the dissolution technique of rhodium are long dissolution period, low dissolution efficiency, high reagent consumption, complex operation, and serious environment pollution. In order to improve the leaching efficiency of rhodium, many researchers focused on clean dissolution and high efficient technique. At the present, the applied dissolution techniques were intermediate temperature chloride-dissolution method and sodium （potassium） bisulfate fusion-dissolution method with some problems. In this work, microwave roasting was used to recovery rhodium from the leached residue of spent automobile catalysts. The impacts of various factors ; reaction temperature, reaction time and proportion of solid to reagent on the rhodium leaching efficiency were studied. The re- sult indicates that microwave heating, through accelerating molecular vibration, smashing the particles, and enhancing the contacting area of solid and liquid, increasing heat and mass transfer processes, finally speeds up the reaction, reduces reagent consumption and obviously improves leaching efficiency. Under the best experimental condition, the proportion of material and reagent is 1： 10, the reaction temperature is 600 ℃ and the holding time is 60 rain. Leaching ratio of rhodium reaches 99.79%. The technique that with less environment pollution, high efficiency of dissolution and high leaching rate has a wide application prospect provides a technical guid- ance for the recovery of, rhodium from spent catalysts of automobile exhaust.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2012年第6期979-984,共6页
Chinese Journal of Rare Metals
关键词
铑
汽车尾气废催化剂
湿法冶金
微波焙烧
rhodium
spent automobile catalysts
hydrometallurgy
microwave roasting
