砷碱渣/高砷锑烟尘协同脱砷及有价金属回收

采用砷碱渣代替碳酸钠与高砷锑烟尘进行协同脱砷并回收其中的有价金属。将碳酸钠、低砷碱渣、高砷碱渣分别与高砷锑烟尘按一定比例混合,通过焙烧-浸出-过滤工艺得到含砷浸出液和有价金属富集渣。结果表明,当原料配比分别为m_碳酸钠∶m_{高砷锑烟尘}=0.8、m_低砷碱渣∶m_{高砷锑烟尘}=3.0、m_高砷碱渣∶m_{高砷锑烟尘}=1.0时,砷浸出率分别为97.5%、96.9%、99.2%; 铅、锑浸出损失少而富集于浸出渣中,渣中有价金属总含量大于68.7%,且浸出渣中砷含量小于1.0%。该工艺砷脱除率高、有价金属回收率高,证明将堆存的砷碱渣直接用作脱砷剂,可以实现以废治废、资源回收,有效降低脱砷成本。

Arsenic Removal and Valuable Metal Recovery from High Arsenic-and-Antimony Flue Dust by Using Arsenic-Alkali Residue

Arsenic-alkali residue instead of sodium carbonate was used to remove arsenic and recover valuable metals from flue dust with high content of arsenic and antimony. Sodium carbonate, low-arsenic alkaline residue or high-arsenic alkaline residue was mixed with the high arsenic-and-antimony flue dust respectively at a certain ratio, and arsenic-bearing leach solution and valuable metal-enriched residue were obtained by roasting-leaching-filtering process. The results show that with a mass ratio of sodium carbonate, low-arsenic alkali residue and high-arsenic alkali residue to high arsenic-and-antimony flue dust at 0.8, 3.0 and 1.0, respectively, the arsenic leaching rates are 97.5%, 96.9% and 99.2%, respectively; the lead and antimony are enriched into the leach residue with little leaching loss, with the total content of valuable metals more than 68.7% and the arsenic content less than 1.0% in the leach residue. It is shown that this process can bring in high arsenic removal rate and high recovery rate of valuable metals, which proves that the piled-up arsenic-alkali residue can be directly used as arsenic removal agent, thus not only achieving waste utilization and resources recovery, but also effectively reducing arsenic removal cost.