研究低温碱性熔炼过程中废弃电路板多金属粉末有价金属的元素行为,在熔炼过程中,Sn、Pb、Zn等两性金属与碱及氧化剂反应生成相应的可溶性碱金属钠盐,通过水浸实现与其他金属分离,取得良好的转化效果。探索了氧化剂用量、碱用量、熔炼温度、熔炼时间、液固比、浸出温度、浸出时间等7个因素对金属转化率的影响,优化得到较为适宜的熔体组成与工艺条件:熔体中多金属粉末、NaNO3、NaOH的质量比为1:3.0:3.6,773 K(500℃)条件下熔炼90 min后,冷却粉碎,加水至液固比为9,加热至313K(40℃)浸出60min。在此优化工艺条件下,各金属的转化率依次为Sn 95.93%、Zn 96.63%、Pb 91.21%和Sb 24.68%。
The elemental behavior of valuable metals in multi-component metal powder(MMP) originated from waste printed circuit board(PCB) was investigated.The applied method of low-temperature alkaline smelting can convert amphoteric metals Sn,Pb and Zn into soluble sodium salts that can be separated from the other metals in leaching process efficiently.The effects of oxidant and alkaline addition,smelting temperature and time,liquid-solid ratio,leaching temperature and time on the metal conversion rate(R) were investigated.The composition of melt and optimum conditions are obtained as mass ratio of MMP,NaNO3 and NaOH being 1:3.0:3.6,smelting for 90min at 773 K(500 ℃),leaching for 60min at 313 K(40 ℃) in water solution(L/S=9).The conversion rates of the metals are as follows: Sn 95.93%,Zn 96.63%,Pb 91.21%,Sb 24.68%.