[Bmim]HSO_4离子液体强化硫脲浸取银矿物  

Intensification of Silver Leaching Process by [Bmim]HSO_4 from

作　　者：方夕辉[1,2] 童雄[1,3] 钟名清 陈文亮[2] 

机构地区：[1]昆明理工大学国土资源工程学院,云南昆明650093 [2]江西理工大学资源与环境工程学院,江西赣州341000 [3]云南省金属矿尾矿资源二次利用工程研究中心,云南昆明650093

出　　处：《稀有金属》2014年第3期464-470,共7页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51174103;51104077);江西省科技支撑计划项目(2011BBG70002-2);江西省教育厅科技计划项目(GJJ11480)资助

摘　　要：针对硫化银和纯银粉中银的浸出,在以[Bmim]HSO4离子液体调节pH值,Fe2(SO4)3为氧化剂,硫脲为浸出试剂的浸取体系中,研究了pH值、浸出时间、硫脲浓度、氧化剂用量、温度、搅拌速度等因素对银浸出率的影响,并对其强化浸出机制进行了初步探讨。研究结果表明[Bmim]HSO4可强化硫脲浸银,在[Bmim]HSO4浓度为0.30 mol·L-1(pH=1.0),硫脲浓度0.16 mol·L-1,Fe3+浓度11.25×10-3mol·L-1,搅拌速度250 r·min-1,浸出时间24 h,浸出温度298 K的条件下,银的浸出率可以达到78.85%,而以H2SO4调节浸液pH=1时,银浸出率仅为51.10%。对硫脲稳定性的研究表明,[Bmim]HSO4在银浸出过程中不但起到调节浸液pH值的作用,也减少了硫脲的氧化分解,硫脲在[Bmim]HSO4溶液中的剩余浓度比在H2SO4溶液中高12.56%。研究也表明[Bmim]HSO4在银浸出过程中减少了硫化银的二次沉淀。[Bmim]HSO4离子液体作为一种新型浸出溶剂,创造了一个更加有利于银溶解的溶液环境。In order to leach silver from a mixture of silver sulfide and silver powder in the aqueous solvents, [ Bmim ] HSO4 as pH regulator, Fe2 （SO4 ）3 as oxidant, thiourea as lixiviant, the process parameters, such as pH value, leaching time, thiourea concentration, oxidant concentration, temperature, stirring speed, and its intensified mechanism of silver leaching by [ Bmim ] HSO4 were stud- ied. The results showed that the leaching efficiency could reach 78.85% under the optimal conditions of c（ [ Bmim] HSO4 ） =0.30 mol · L^-1（ pH = 1.0）, c（thiourea） =0.16 mol· L^-1, c（ Fe^3＋ ） = 11. 25 × 10^-3 mol·L^-1, agitation speed 250 r·min^-1 , t（ leaching time） = 24 h, T（ leaching temperature） = 298 K. But the leaching efficiency of silver by H2 SO4 was only 51.10% under similar conditions. Experimental investigation on thiourea stability showed that, [ Bmim ] HSO4 not only played the role of pH adjustment infusion, but also reduced oxidative decomposition of thiourea. Thiourea remaining concentration ratio in [ Bmim] HSO4 solution was 12.56% higher than that in the HESO4 solution. And silver sulfide secondary precipitation was inhibited in [ Bmim] HSO4 aqueous solvents. [ Bmim] HSO4, a kind of new leaching solvent, created a solution environment to promote the silver leaching reaction.

关 键 词：1-丁基-3-甲基咪唑硫酸氢盐 离子液体 银 浸出 硫脲 pH调整剂 

分 类 号：TD953[矿业工程—选矿]