蒸硒渣中稀贵金属提取工艺

Extraction technology of rare and precious metals from selenium-removed residues

针对粗硒真空蒸馏产出的蒸硒渣,开发了碱性氧化焙烧/硫酸化焙烧-湿法联合梯级处理工艺,对比研究了不同处理方法对蒸硒渣中稀贵金属浸出率的影响。结果表明:采用碱性氧化焙烧-湿法联合工艺处理蒸硒渣时,Au、Ag、Pt、Pd的浸出率分别为53.18%、18.32%、96.64%、98.14%,Se浸出率>99%,Te、Cu的浸出率分别为74.66%、83.55%;采用硫酸化焙烧-湿法联合工艺处理蒸硒渣时,Au、Ag、Pt、Pd的浸出率分别为99.33%、99.95%、96.49%、95.26%,Se浸出率为99.97%,Te、Cu的浸出率分别为98.52%、99.98%。碱性氧化焙烧-湿法联合梯级处理工艺对设备腐蚀较严重,操作难度较大;硫酸化焙烧-湿法联合梯级处理工艺对Au、Ag及Te、Cu的回收效果优于碱性氧化焙烧处理工艺,且操作简便,可直接嫁接于现有的生产线,应用前景广阔。

For extracting rare and precious metals in the selenium-removed residues produced by vacuum distillation of crude selenium,the alkaline oxidation roasting/sulfation roasting-hydrometallurgy combined cascade treatment processes were developed,and the effects of different treatment methods on the leaching efficiencies of rare and precious metals in selenium-removed residues were compared and studied.The results show that,when the alkaline oxidation roasting-hydrometallurgy combined process is used to treat selenium-removed residues,the leaching efficiencies of Au,Ag,Pt and Pd are 53.18%,18.32%,96.64%and 98.14%,respectively,the leaching efficiency of Se is more than 99%,and the leaching efficiencies of Te and Cu are 74.66%and 83.55%,respectively.When the sulfated roasting-hydrometallurgy combined process is used to treat Se-removed selenium-removed residues in cascade,the leaching efficiencies of Au,Ag,Pt and Pd are 99.33%,99.95%,96.49%and 95.26%,respectively,the leaching efficiency of Se is 99.97%,and the leaching efficiencies of Te and Cu are 98.52%and 99.98%,respectively.The alkaline oxidation roasting-hydrometallurgy combined cascade treatment process has serious corrosion on equipment and containers,and is difficult to operate.The sulfation roasting-hydrometallurgy combined cascade treatment process has better recoveries of Au,Ag,Te,and Cu than the alkaline oxidation roasting process.It is easy to operate and can be directly grafted onto the existing production line.It has broad application prospects.