汽車廢催化劑中的貴金屬
(昆明貴金屬研究所， 昆明 650221)
摘 要: 為提高鉑族金屬的浸出回收率， 針對(duì)前期研究提出的汽車廢催化劑先經(jīng)加壓堿浸處理而后再加壓氰化浸出鉑族金屬的新工藝，變動(dòng)預(yù)處理反應(yīng)過程各種工藝參數(shù)， 考察了對(duì)后續(xù)鉑族金屬氰化浸出指標(biāo)的影響。 結(jié)果表明： 預(yù)處理可打開汽車廢催化劑載體對(duì)鉑族金屬的包裹， 有利于其氰化浸出； 但物料粒度過細(xì)或反應(yīng)堿用量過大、溫度過高、 時(shí)間過長均容易形成新相重新包裹， 不利于氰化試劑與鉑族金屬有效接觸； 預(yù)處理渣進(jìn)一步濕磨， 可消除包裹， 提高氰化浸出率； 在實(shí)驗(yàn)最佳條件下， 鉑族金屬氰化浸出率分別可達(dá)到： Pt 96%、 Pd 98%、 Rh 92%。
關(guān)鍵字: 鉑族金屬； 失效汽車催化劑； 加壓堿浸處理； 加壓氰化浸出
LI Qi-wei， YANG Qiu-xue
（ Kunming Institute of Precious Metals， Kunming 650221, China）
Abstract: 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.
Key words: platinum-group metals; spent auto-catalysts; pressure alkali treatment; pressure cyanide leaching
