A novel low-temperature alkaline smelting process is proposed to convert and separate amphoteric metals in crushed metal enrichment originated from waste printed circuit boards. The central composite design was used to optimize the operating parameters,in which mass ratio of Na OH-to-CME, smelting temperature and smelting time were chosen as the variables, and the conversions of amphoteric metals tin, lead, aluminum and zinc were response parameters. Second-order polynomial models of high significance and3 D response surface plots were constructed to show the relationship between the responses and the variables. Optimum area of80%-85% Pb conversion and over 95% Sn conversion was obtained by the overlaid contours at mass ratio of Na OH-to-CME of4.5-5.0, smelting temperature of 653-723 K, smelting time of 90-120 min. The models were validated experimentally in the optimum area, and the results demonstrate that these models are reliable and accurate in predicting the smelting process.
采用低温碱性熔炼处理铜阳极泥(CAS),研究熔炼浸出过程各有价金属的分离富集行为。分析碱料比、熔炼温度、熔炼时间、浸出温度、浸出时间和液固比等6个因素对金属浸出率的影响。结果表明:优化条件为碱料比为0.5,熔炼温度为600℃,熔炼时间为60 min,浸出温度为70℃,浸出时间为60 min,液固比为12.5 m L/g。在此优化条件下,Se和As的浸出率分别达95.79%和96.83%,Cu、Pb、Sb和Te的浸出率分别为0.16%、3.36%、1.02%和0.05%,实现了铜阳极泥中有价金属的有效分离和富集。
