Zn-recovery from steel making dusts - Kinetics and mechanism of thermal zinc-ferrite phase decomposition

从炼钢粉尘中回收锌 - 热锌铁氧体相分解的动力学和机理

• 批准号: 42595291
• 负责人: Professor Dr.-Ing. Bernd Friedrich
• 金额: --
• 依托单位: Institut für Metallurgische Prozesstechnik und Metallrecycling (IME)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/42595291?language=en
• 关键词: Zn; recovery; steel; making; dusts

Zinc-iron concentrate as a by-product from EAF-dust processing (as well as from primary ore processing) counts as waste for disposal, although an available content of zinc represents about from 300 to 500 €/t. Every year approx. 65.000-75.000 tons zinc are lost in European countries. In former times this material was consumed in West-European Imperial Smelting Furnaces, but this technology now it is not accessible anymore after closure of those plants. Because of the presence of Cd, Zn and As in such materials their recycling disposal is not acceptable. At the moment the yield of metals by existing metallurgical treatment processes amounts smaller than 20 %. The high content of sulphur (5-13 mass percent) does not allow a treatment in the common Waelz process. This project focuses on a pyrometallurgical treatment of iron-zinc concentrate in order to study the mechanism and kinetics of thermal zinc ferrite phase decomposition. Fundamental experiments in a modified Tamman furnace should be performed in a very weak reducing atmosphere at 1150°C to prevent Zinc-gas-formation. After established optimal parameters the thermal decomposition of zinc ferrite will be investigated in a rotary kiln furnace in order to investigate the technical feasibility. The chemical equilibrium and the kinetics of this process step as well as for the subsequent hydrometallurgical recovery of zinc from a solid residue is studied with suitable computer models and validated under laboratory conditions. The research will be conducted as a DFG-partner project with the Institute of Chemical Technology in Prague.

锌铁精矿作为电炉粉尘加工（以及初级矿石加工）的副产品，被视为废物处理，尽管锌的有效含量约为300至500欧元/吨。每一年都在逼近。欧洲国家损失了65，000 - 75，000吨锌。在过去，这种材料是在西欧帝国冶炼厂消耗的，但在这些工厂关闭后，这种技术现在不再可用。由于这些材料中存在Cd、Zn和As，它们的回收处理是不可接受的。目前，通过现有的冶金处理方法，金属的产率小于20%。高含量的硫（5-13质量%）不允许在普通Waelz方法中进行处理。本计画以铁锌精矿为研究对象，探讨铁酸锌相热分解的机制与动力学。在改进的塔曼炉中进行的基础实验应在1150°C的极弱还原气氛中进行，以防止锌气形成。在确定了最佳工艺参数后，在回转窑炉中对铁酸锌的热分解进行了研究，以考察其技术可行性。该工艺步骤的化学平衡和动力学以及随后从固体残渣中湿法回收锌的化学平衡和动力学用合适的计算机模型进行了研究，并在实验室条件下进行了验证。该研究将作为DFG与布拉格化学技术研究所的合作项目进行。