论文部分内容阅读
传统湿法炼锌中的氧化焙烧阶段产生大量铁酸锌,在常规条件下铁酸锌难以溶出,不利于铁锌的分离和回收。铁酸锌的生成导致后续沉铁工序复杂,渣量大,既浪费了锌铁资源又污染环境。提出了一种新的还原焙烧方法,使高铁锌焙砂中的铁酸锌选择性分解为氧化锌和磁性氧化铁。以北京某锌冶炼厂的锌焙砂为研究对象,研究铁酸锌选择性分解为氧化锌和磁性氧化铁过程中的变化规律,寻找最佳还原焙烧条件。采用化学分析法和XRD检测技术研究了锌焙砂还原焙烧过程中焙烧温度、焙烧时间、CO体积分数和CO/CO2配比等因素对亚铁生成量、可溶锌率及锌浸出率的影响。结果表明,在750℃、CO体积分数为4%、CO/(CO+CO2)体积比为20%、焙烧60 min的焙烧条件,以及浸出酸度为150 g/L H2SO4、液固比为15∶1、转速为500 r/min、30℃的浸出条件下,锌的浸出率为93.24%,实现了铁锌的有效分离。
Traditional wet zinc smelting in the oxidation roasting stage produces a large number of zinc ferrite, zinc leaching difficult under normal conditions, is not conducive to iron and zinc separation and recovery. The formation of zinc ferrite led to the subsequent iron sink complex process, large amount of slag, both waste of zinc and iron resources and pollute the environment. A new reduction roasting method was proposed to selectively decompose zinc ferrite in high-iron-zinc calcine to zinc oxide and magnetic iron oxide. Taking zinc roaster in a zinc smelter in Beijing as the research object, the variation regularity of zinc ferrite in the process of selective decomposition into zinc oxide and magnetic iron oxide was studied in order to find out the best reduction roasting conditions. The effects of calcination temperature, calcination time, CO volume fraction and CO / CO2 ratio on the production of ferrous iron, the soluble zinc content and the zinc leaching rate were investigated by chemical analysis and XRD. . The results showed that at 750 ℃, the CO concentration was 4%, the volume ratio of CO / (CO + CO2) was 20%, the calcination time was 60 min, the leaching acidity was 150 g / 1, the rotating speed is 500 r / min, the leaching rate of zinc is 93.24% under the leaching condition of 30 ℃, which achieves the effective separation of iron and zinc.