加压碱浸处理氰化浸出法回收汽车废催化剂中的贵金属

为提高铂族金属的浸出回收率,针对前期研究提出的汽车废催化剂先经加压碱浸处理而后再加压氰化浸出铂族金属的新工艺,变动预处理反应过程各种工艺参数,考察了对后续铂族金属氰化浸出指标的影响。结果表明:预处理可打开汽车废催化剂载体对铂族金属的包裹,有利于其氰化浸出;但物料粒度过细或反应碱用量过大、温度过高、时间过长均容易形成新相重新包裹,不利于氰化试剂与铂族金属有效接触;预处理渣进一步湿磨,可消除包裹,提高氰化浸出率;在实验最佳条件下,铂族金属氰化浸出率分别可达到:Pt 96%、Pd 98%、Rh92%。

Recovery of precious metals from spent auto-catalysts by method of pressure alkaline treatment-cyanide leaching

Recovery of platinum group metals from spent auto-catalysts by pressure alkaline treatment-cyanide leaching was investigated.Influences of changing parameters of process of pressure alkaline treatment on later percent pressure cyanide leaching of PGMs were discussed.The research results indicate that the wrapping of PGMs by catalyst carriers can be destroyed in pretreatment process,and so that is in favor of their cyanide leaching.However if the sample's granularity too small,addition of NaOH too more,reaction temperature too high,or reaction time too long,there are insoluble new substances formed and PGMs are re-wrapped.For obtaining higher percent metal recovery,further grinding of pretreatment residue is needed.Under the optimal controlling conditions,the ratio of PGMs cyanide leaching can reach Pt 96%,Pd 98% and Rh 92% respectively.