Cr_2O_3含碳球团的还原过程

Reduction process of Cr_2O_3 / carbon pellets

为了解不锈钢冶炼粉尘中三氧化二铬的还原特性和还原过程的主要影响因素,采用纯Cr2O3粉末与碳粉、氧化钙、铁粉混合制粒成球,通过实验研究温度、含碳量和球团大小对还原度和还原过程的影响,并建立还原过程的动力学模型。研究结果表明:Cr2O3的碳热还原可分为前期和后期2个阶段,前期为化学反应控制,动力学方程为g(f)=(0.29m-0.01)t.exp[-60370/(RT)];还原过程后期为扩散控制,其动力学方程为g(f)=(-0.17w+0.31)t.exp[-99435/(RT)]。

In order to research the reduction characteristics of chromium oxide present in stainless steelmaking dust and the parameters of its reduction process, pure Cr2O3 powder was mixed to make the pellets with carbon, CaO and iron powders, and the influence of reduction temperature, carbon content and the diameter of pellets on the recovery of metal value and whole thermal reduction process was investigated using an electric furnace in nitrogen atmosphere. The results show that the reduction process of chromium oxide can be classified into two stages. The initial stage is controlled by chemical reaction between the chromium oxide and carbon, and the kinetic equation of the reduction process can be expressed as g（f）=（0.29ω-0.01）t·exp[-60370/（RT）]. The following stage is controlled by the diffusion of reduced products, and the kinetic equation of this stage can be expressed as g（f）=（-0.17ω＋0.31）t·exp[-99435/（RT）].