Abstract

A mechanism is proposed for the joint reduction of oxides from multicomponent copper-smelting slag when they are blown with CO–CO₂ gas mixtures and an algorithm is developed for its implementation in the form of a mathematical model. The first feature of the proposed mechanism is that the total rate of the overall reduction process is determined by CO consumption in the course of its interaction with oxygen ions formed owing to the dissociation of slag oxides. The second feature is that the equilibrium between the slag, alloy, and gas phase is achieved in accordance with the oxidation potential of the system occurring at each moment of time. It is shown that there is a satisfactory agreement between the calculated and experimental data obtained in the course of the reduction of the industrial copper-smelting slag at a temperature of 1300°C and at a ratio of CO/CO₂ = 4, 6, and 156. In this case, a first-order kinetic equation is valid with respect to the difference between the initial and equilibrium CO content in the gas phase. A generalized rate constant for the reduction of multicomponent slag has been calculated amounting to k = 2.6 × 10^–7 mol_CO/(cm² s%) at a temperature of 1300°С. It is shown that, under the reduction of industrial multicomponent slag, the reduction rates for copper oxide and magnetite are rather high, being close to the maximum value at the very beginning of the slag blowing with the reducing gas. At the same time, the reduction rates for ferrous oxide and for the oxides of zinc and lead in the first minutes of the process are insignificant and exhibit a gradual increase before reaching a maximum, after which they again decrease almost to zero values as the system approaches the equilibrium between the supplied gas and the melt. In general, the reduction rate of oxides decreases when the equilibrium between the initial gas and the liquid phase is approached, and this should be taken into account when organizing the processes of continuous slag depletion.

中文翻译：

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CO-CO 2混合气吹制还原铜熔渣中氧化物的机理

摘要

提出了一种在多组分铜冶炼炉渣中吹入CO-CO ₂的氧化物联合还原的机理气体混合物，并开发了一种以数学模型形式实施的算法。所提出的机理的第一个特征是，整个还原过程的总速率由一氧化碳消耗量决定，该消耗量是一氧化碳与炉渣氧化物解离形成的氧离子相互作用的过程。第二个特征是，根据在每个时间点发生的系统氧化电位，可实现炉渣，合金和气相之间的平衡。结果表明，在1300℃的温度和CO / CO ₂的比例下还原工业铜冶炼炉渣过程中获得的计算数据与实验数据之间令人满意的一致性。= 4、6和156。在这种情况下，一阶动力学方程对于气相中初始和平衡CO含量之间的差异有效。计算出的用于还原多组分炉渣的广义速率常数为k = 2.6×10 ^–7 mol _CO /（cm ² s％）在1300°С的温度下。结果表明，在工业多组分炉渣的还原过程中，氧化铜和磁铁矿的还原率相当高，接近于用还原性气体吹渣的最开始时的最大值。同时，在过程的最初几分钟内，氧化亚铁以及锌和铅的氧化物的还原速率微不足道，并且在达到最大值之前呈现逐渐增加的趋势，此后随着系统的存在，它们再次降低至几乎为零。接近供应的气体和熔体之间的平衡。通常，当达到初始气体和液相之间的平衡时，氧化物的还原率会降低，在组织连续排渣过程时应考虑到这一点。