The presence of iron in sphalerite induces the formation of zinc ferrite (ZF) during roasting. Zinc refinery residues (ZRR) and electric arc furnace dust (EAFD) contain a significant amount of zinc ferrite and are difficult to treat. According to the literature, up to 71% ZF has been found to be present in ZRR. The dissolution of zinc ferrite is inefficient even in aqua regia. The Waelz process is an existing process to recover zinc from electric arc furnace dust by reduction using carbon monoxide followed by the volatilization of zinc. In this study, zinc was selectively extracted from zinc ferrite by partial reduction of zinc ferrite at relatively low temperature followed by leaching in dilute sulfuric acid (20 g/L). Pure zinc ferrite samples were partially reduced to zinc oxide and magnetite by using H2 gas as a reductant. The presence of magnetite and zinc oxide was confirmed by X-ray diffraction (XRD) technique. A maximum of 95% zinc extraction was achieved after leaching with sulfuric acid on the reacted samples. The paper also discusses the effect of time, temperature, and concentration of H2 in the reducing gas on the extraction of zinc and iron from ZF.

中文翻译：

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从铁酸锌中选择性提取锌

闪锌矿中铁的存在会在焙烧过程中诱导铁酸锌 (ZF) 的形成。锌精炼残渣 (ZRR) 和电弧炉粉尘 (EAFD) 含有大量铁酸锌，难以处理。根据文献，已发现高达 71% 的 ZF 存在于 ZRR 中。即使在王水中，铁酸锌的溶解效率也很低。Waelz 工艺是一种现有工艺，通过使用一氧化碳还原，然后使锌挥发，从电弧炉粉尘中回收锌。在本研究中，通过在相对较低的温度下部分还原铁酸锌，然后在稀硫酸 (20 g/L) 中浸出，从铁酸锌中选择性提取锌。通过使用氢气作为还原剂，纯锌铁氧体样品被部分还原为氧化锌和磁铁矿。通过 X 射线衍射 (XRD) 技术证实了磁铁矿和氧化锌的存在。用硫酸浸出反应后的样品后，锌提取率最高可达 95%。论文还讨论了时间、温度和还原气中 H2 浓度对从 ZF 中提取锌和铁的影响。