A Novel Hematite-Catalyzed Approach for Iron Removal from Zinc Sulfate Solutions
Abstract
The article presents the results of a study on the removal of iron (III) ions from complex zinc sulfate solutions obtained through direct atmospheric leaching of low-grade zinc ores and iron-rich slag. Hematite (Fe2O3) was used as a catalyst for iron ion precipitation, while zinc oxide and quicklime were used in equal proportions for solution neutralization. Iron precipitation was carried out in the presence of hematite at a pH range of 0.05–2.2. Experimental results showed that the mass fraction of iron in the precipitate increased by 8–18% compared to traditional methods. The content of non-ferrous metals, including zinc, decreased from 0.75% to 0.18%, and no sulfide sulfur was detected in the precipitate. Complete precipitation was achieved at a temperature of 77–78 °C and a pH of 2.2 over a period of 180 minutes. The precipitate contained up to 68.3% iron with minimal zinc content of 1%, confirming the high efficiency of the purification process. The use of hematite accelerated the hydrolysis process and reduced energy consumption. The study's findings confirm the high efficiency of the proposed method, its potential for industrial application, and its alignment with global goals for environmentally sustainable development.