采用溴代十六烷基吡啶从碱性氰化液中萃取和富集钯、铂

Simultaneous extraction and preconcentration of palladium and platinum from alkaline cyanide solution by hexadecylpyridinium bromide

对使用溴代十六烷基吡啶(HPB)作为萃取剂,在碱性氰化液中同时萃取富集钯、铂进行考察,对影响萃取富集效率的各种因素:稀释剂种类、溴代十六烷基吡啶浓度、改性剂用量、相比、萃取时间、水相中Pd(II)和Pt(II)浓度及溶液的p H值进行研究。结果表明:使用溴代十六烷基吡啶浓度为0.05 mol/L,正辛醇含量为30%(体积分数),相比(O/A)为1:5的有机相,在p H=10.5碱性氰化液中,5 min内能将Pd(II)(<70 mg/L)和Pt(II)(<60 mg/L)从水相转移至有机相,采用NH_4SCN溶液反萃有机相中的Pd(II)和Pt(II),采用斜率法、红外和紫外光谱分析对萃取机理进行推测,该方法可运用于钯、铂浮选精矿氰化浸出液中Pd(II)和Pt(II)的萃取,富集倍数为15,回收率大于95%。

Simultaneous extraction and preconcentration of Pd(II) and Pt(II) from alkaline cyanide solution using hexadecylpyridinium bromide(HPB) as extractant were investigated. The factors affecting extraction and preconcentration efficiency, including diluent type, concentration of hexadecylpyridinium bromide, content of modifier, phase ratio(O/A), contact time of aqueous and organic phase, concentrations of Pd(II) and Pt(II) and p H value of solution, were studied. The results indicate that, at concentration of hexadecylpyridinium bromide(HPB) 0.05 mol/L, content of n-octyl alcohol 30%(volume fraction), phase ratio(O/A)=1:5, p H values 10.5 contact time of 5 min, Pd(II)(<70 mg/L) and Pt(II)(<60 mg/L) in alkaline cyanide solution can be transferred from the aqueous phase into the organic phase. Ammonium thiocyanate solution can be used as stripping agent. The extraction mechanism can be deduced based on slope analysis,FTIR spectrum and UV spectrum. The proposed method was applied to extract of Pd(II) and Pt(II) from leaching cyanide liquor of Pt-Pd flotation concentrate. The enrichment factor of 15 is achieved. The recovery rate is high than 95%.