锌冶炼渣搭配铅精矿侧吹还原熔炼直接炼铅渣型理论研究

Fundamental Research on Slag Type of Zinc Leaching Residue with Lead Concentrate in Lead Smelting by Side Blowing Reduction

以FeO-Fe_(2)O_(3)-SiO_(2)-CaO-ZnO-PbO渣系为研究对象,采用热力学软件FactSage计算温度、Fe/SiO_(2)(质量比)、CaO/SiO_(2)(质量比)、ZnO含量及PbO含量等因素对炉渣熔化温度及液相生成区的影响。热力学分析表明,随着Fe/SiO_(2)的增大,炉渣熔化温度减小,随着CaO/SiO_(2)的提升呈先减小后增大的趋势。炉渣中ZnO含量在10%~18%变化时,炉渣的熔化温度变化较大。随着ZnO含量的增加,炉渣的液相区有所减小,当渣中ZnO含量低于12%时,可保证还原熔炼的顺利进行。验证试验表明,在熔炼温度1 200~1 250℃、CaO/SiO_(2)=0.5、Fe/SiO_(2)=0.9、ZnO含量12%的条件下,采用侧吹还原熔炼处理液态高铅渣可顺利进行,熔炼过程金属直收率为85%,渣中铅含量为2.06%。

Phase diagrams of FeO-Fe_(2)O_(3)-SiO_(2)-CaO-ZnO-PbO slag system were calculated with FactSage thermodynamics software.Effects of temperature,Fe/SiO_(2)(mass fraction),CaO/SiO_(2)(mass fraction),ZnO content,and PbO content on melting temperature and liquid phase generation zone of slag were investigated.Thermodynamic analysis shows that melting temperature of slag drops with increase of Fe/SiO_(2),and drops first and rises later with increase of CaO/SiO_(2).When ZnO content in slag is 10%-18%,melting temperature of slag varies greatly.However,liquid phase area of slag shows a decreasing trend as content of ZnO rises.Under the premise of ensuring smooth progress of smelting process,content of ZnO in slag can be controlled to be lower than 12%.Verification experiment shows that under the conditions of1 200-1 250℃,CaO/SiO_(2)=0.5,Fe/SiO_(2)=0.8,and ZnO content of 12%,treating of liquid high-lead slag using side blowing reduction smelting can proceed smoothly,metal direct recovery rate during reduction is 85%,and lead content in reduced slag is 2.06%.