铅鼓风炉中铜、硫、砷和锑对银分布的影响

摘要

An experimental study was carried out to estimate the effect of the lead impurities on the silver distribution in the phases formed in the lead blast furnace. Samples of sinter with different contents of Cu, S, As and Sb were equilibrated under reducing atmosphere (p(CO)/p(CO2)=2.45) at 1573 K in a tube furnace and slowly cooled. The samples were characterized by scanning electron microscopy and microanalysis (SEM-EDS). There were five immiscible phases:slag (CaO, FeO and SiO2), matte (S, Cu and Fe), speiss (As, Fe and Cu), Cu-Sb phase and lead bullion (Pb, Ag, Sb, Cu, etc). The results showed that Cu and Sb promote silver losses during the process since they form a liquid solution with higher silver solubility than liquid bullion. Sulfur and arsenic react with copper to form the matte and speiss phases, respectively. The effect of S and As is to reduce the amount of Cu-Sb alloy and then the silver losses from the bullion.%研究铅鼓风炉中杂质对银分布的影响。将含有不同Cu、S、As和Sb含量的铅烧结块在管式炉中于1573 K下进行烧结，然后随炉冷却。烧结气氛为还原性的CO+CO2气体(p(CO)/p(CO2)=2.45)。采用SEM-EDS对所得样品进行表征。结果表明：烧结样品中含有5种不互溶的相，即炉渣(CaO，FeO，SiO2)、冰铜(S, Cu，Fe)、硬渣(As, Fe，Cu)、Cu-Sb相和铅块。银在Cu与Sb形成的熔体中的溶解度比在液态铅中的高。S与Cu形成冰铜， As与Cu形成硬渣。S和As能减少Cu-Sb合金的生成量，从而降低铅块中银的损失。