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

虽然锌的可用含量约为每吨300至500欧元，但作为电炉粉尘处理（以及初级矿石处理）的副产品的锌铁精矿仍被视为废物。大约每年。欧洲国家损失了65000 - 75000吨锌。在以前，这种材料是在西欧帝国熔炼炉中消耗的，但在这些工厂关闭后，这种技术现在已经无法使用了。由于这些材料中含有Cd、Zn和As，因此回收处理是不可接受的。目前，现有的冶金处理工艺的金属收率还不到20%。高硫含量（5-13质量百分比）不允许在普通的Waelz工艺中进行处理。本课题以铁锌精矿为研究对象，研究铁酸锌热相分解的机理和动力学。为了防止锌气体的形成，应在1150°C的极弱还原气氛中在改进的塔曼炉中进行基础实验。确定最佳工艺参数后，将在回转窑中对铁氧体锌进行热分解试验，以考察工艺的可行性。用合适的计算机模型研究了这一过程的化学平衡和动力学，以及随后从固体残渣中湿法冶金回收锌的动力学，并在实验室条件下进行了验证。这项研究将作为布拉格化学技术研究所的dfg伙伴项目进行。

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.