Faculty of Chemistry, University of Warsaw, Pasteura 1, PL-02-093 Warsaw, Poland.
Faculty of Chemistry, Biological and Chemical Research Center, University of Warsaw, Żwirki i Wigury 101, PL-02-089 Warsaw, Poland.
Molecules. 2019 Jun 19;24(12):2275. doi: 10.3390/molecules24122275.
A method for processing of metallurgical waste materials (chemically defined as sulfur-bearing zinc-ferric materials) produced by plants processing zinc ores and their concentrates is proposed. The method proposed is a combination of pyro- and hydrometallurgical treatments of the waste material. The crucial steps in the developed method include: roasting the material at 450 °C to generate sulfur dioxide (SO), absorption of SO in an aqueous system to form sulfuric acid (IV), carbothermic decomposition of zinc ferrite compounds, and leaching of zinc from the roasted material using sulfuric (IV) acid. The method allows one to extract up to 40% of zinc from the waste material and, consequently, to generate a fraction of material with substantially higher content of iron oxides. The proposed method takes advantage of the presence of sulfur in the processed material which upon roasting is converted to sulfuric acid (IV)-a leaching agent for selective extraction of zinc. The properly adjusted pH of the aqueous medium in which the leaching process is carried out is the key factor determining the quantitative and selective separation of zinc. If the amount of sulfur in the processed material is insufficient, it may be supplemented by adding sulfuric acid (VI) to adjust the pH. The method proposed was tested at a laboratory scale and quarter industrial scale using the real samples taken from stockpiles in the vicinity of the plant processing zinc and lead ores in Poland. It may also work for any zinc-ferric materials from various sources.
一种处理冶金废料（化学定义为含硫锌铁材料）的方法被提出，这些废料是由处理锌矿石及其精矿的工厂产生的。所提出的方法是火法和湿法冶金处理废料的结合。该方法的关键步骤包括：在 450°C 下对物料进行焙烧，以生成二氧化硫（SO），将 SO 在水溶液中吸收形成硫酸（IV），对锌铁化合物进行碳热分解，以及用硫酸（IV）酸从焙烧物料中浸出锌。该方法可从废料中提取高达 40%的锌，从而生成铁氧化物含量显著提高的物料部分。该方法利用了处理物料中存在的硫，在焙烧过程中硫转化为硫酸（IV），硫酸（IV）是选择性提取锌的浸出剂。在进行浸出过程的水溶液中适当调整 pH 值是决定锌定量和选择性分离的关键因素。如果处理物料中的硫含量不足，可以通过添加硫酸（VI）来调整 pH 值。该方法已在实验室规模和四分之一工业规模下进行了测试，使用的是从波兰处理锌和铅矿石的工厂附近的库存中采集的实际样品。它也可适用于来自各种来源的任何锌铁材料。
