锌冶炼铅银渣与铅精矿协同处理工艺

Co-processing technology of lead-silver slag from zinc smelting and lead concentrate

铅银渣中含有铅、锌、银等有价金属,处理工艺应实现有价金属回收和无害化两个目的。湿法处理工艺产出的浸出渣仍然属于危废;火法处理工艺中较先进的基夫赛特工艺和Ausmelt工艺采用与铅精矿搭配的方式处理铅银渣,但分别存在生产成本高、建设投资大的问题。本文介绍一种通过氧气底吹熔炼协同处理锌冶炼铅银渣与铅精矿的工艺,理论计算显示在某冶炼厂典型的铅精矿与铅银渣成分且氧化熔炼不需配入燃料的前提下,铅银渣配入最大值为13%。生产实践数据表明,该工艺铅回收率>98%、锌回收率>90%、银回收率>98.5%,资源回收率显著;整个工艺充分利用铅精矿中硫化物氧化放热,吨渣标煤消耗为260~330 kgce/t,实现了铅银渣的低碳处理;工艺流程产生的烟气进行制酸,烟尘回到冶炼炉进行综合回收,废渣可以直接销售给水泥厂进行综合利用,达到了无害化处理的目标。

Lead-silver slag contains lead, zinc, silver and other valuable metals, and the treatment process should achieve two purposes: valuable metal recovery and harmlessness. The leached residue from hydrometallurgical treatment process is still hazardous waste;in the pyrometallurgical treatment process, the more advanced Kivcet process and Ausmelt process, together with lead concentrate process to treat lead and silver slag, however, there exist issues like high production and construction costs. This paper introduces a process of co-processing lead-silver slag from zinc smelting and lead concentrate through oxygen bottom blowing smelting. The theoretical calculation shows that if the composition of lead concentrate and lead-silver slag in a smelter is typical, and under the premise that fuel is not required for oxidative smelting, the maximum value of lead-silver slag is 13%. According to practical production data, the lead recovery rate of this process exceeds 98%, the zinc recovery rate exceeds 90%, the silver recovery rate exceeds 98.5%, and the resource recovery rate is remarkable;The coal consumption is 260-330 kgce/t, which realizes low-carbon treatment of lead and silver slag;the off gas generated by the process is used for acid production, the dust is returned to the smelting furnace for comprehensive recovery, and the slag can be sold directly to the cement plant for comprehensive utilization, which means the goal of harmless treatment has been achieved.