Effective recycling of zinc-containing industrial wastes, most importantly electric arc furnace dust, is of tremendous importance for the circular economy of the steel and zinc industry. Herein, we propose a comprehensive kinetic model of the combined carbothermic and metallothermic reduction of zinc oxide in a metal bath process. Pyro-metallurgical, large-scale lab experiments of a carbon-saturated iron melt as reduction agent for a molten zinc oxide slag were performed to determine reaction constants and accurately predict mass transfer coefficients of the proposed kinetic model. An experimentally determined kinetic model demonstrates that various reactions run simultaneously during the reduction of zinc oxide and iron oxide. For the investigated slag composition, the temperature-dependent contribution of the metallothermic zinc oxide reduction was between 25 and 50 pct of the overall reaction mechanism. The mass transfer coefficient of the zinc oxide reduction quadrupled from 1400 °C to 1500 °C. The zinc recovery rate was > 99.9 pct in all experiments.

中文翻译：

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含锌工业废物的碳热还原：动力学模型

有效回收含锌工业废料，尤其是电弧炉粉尘，对钢铁和锌行业的循环经济具有重要意义。在此，我们提出了在金属浴过程中氧化锌结合碳热和金属热还原的综合动力学模型。进行了碳饱和铁熔体作为熔融氧化锌渣的还原剂的火法冶金大规模实验室实验，以确定反应常数并准确预测所提出的动力学模型的传质系数。实验确定的动力学模型表明，在氧化锌和氧化铁的还原过程中，各种反应同时进行。对于所研究的炉渣成分，金属热氧化锌还原的温度相关贡献在整个反应机制的 25 至 50 pct 之间。氧化锌还原的传质系数从 1400 °C 到 1500 °C 翻了两番。在所有实验中，锌回收率 > 99.9 pct。