室温加压下金属铂不能被氰化钠溶解是动力学因素,高温加压氰化已应用于含铂族金属的废催化剂和含铂钯硫化物浮选精矿的铂钯提取。研究了高温加压氰化金属铂溶解的各种因素。实验结果表明,温度越高,越有利于铂溶解。搅拌速率对金属铂的溶解基本无影响,氰化钠浓度越大,金属铂溶解的速度越快,氧的分压增大铂溶解降低。转速600r·min^-1。温度180℃左右,氰化钠浓度12.5g·L^-1,氧的分压1·0MPa和2h时间以内易于铂溶解。
Reaction between sodium cyanide and platinum does not occur under a pressure at room temperature by poor kinetics. A process of pressure cyaniding at high temperature was applied to electively leaching of platinum-group metals (PGMs) from spent automobile catalysts and Pt-Pd sulfide flotation concentrates was reported. In the present paper, various effects on the dissolution of pressure cyaniding leaching of metal Pt were measured in clear cyanide solution. The results show that dissolution cyaniding Pt was independent on stirring speed and favored at higher temperature in the region of 100~180 ℃, and dissolution of cyaniding metal Pt was increased with increasing cyanide concentration. As increasing oxygen pressure the dissolution was decreased. It is found that the dissolution of cyaniding metal Pt had a relation with the cyanide concentration, oxygen pressure and temperature. Under the conditions, stirring speed 600 r·min^-1, about 180 ℃ and 2 h reaction time, platinum could be leached by sodium cyanide well.