铬铁矿固态碳热还原过程的影响因素

 铬铁矿是一种重要的国家战略资源,它是冶金、耐材和化工领域的重要原料,但在其开采过程中产生的大量矿粉一直难以高效利用.为了能够解决这一难题,科研工作者提出了铬铁矿的固态碳热还原工艺,即将矿石粉末与固体碳的混料在高温炉中直接进行还原反应,此工艺能使铬铁矿中铁的氧化物被选择性还原,从而提高了矿石的铬铁比.本文在系统分析铬铁矿碳热还原反应机理的基础上,着重研究了还原温度、还原时间、还原剂类型、气体流速、矿粉粒度与球团尺寸、添加剂类型等因素对铬铁矿固态碳热还原过程的影响作用,以期为实现低品位铬铁矿粉的高效综合利用提供指导.研究得出多数因素对铬铁矿固态碳热还原反应的影响是非线性的,在作用区间内往往存在最优值.因此,适宜工艺条件的选择对于得到高质量产品、降低生产成本有重要意义.

Influential Factors in the Solid Carbothermic Reduction of Chromite

Chromite is one kind of national strategic resources in the all countries of the world. It is widely used in various fields, such as metallurgy, refractory, and chemical industry, etc. However the large amount of chromite power that is generated by the process of mining is difficult to effectively utilization. In order to solve the problem, researchers put forward the technology of solid carbothermic reduction of chromite. By directly placing the mixed material that contains chromite fines and solid carbon into the high temperature furnace for reduction reaction. In this process, iron oxides are able to be selectively reduced from chromite; therefore higher rate of chromic oxide-ferrous oxide to chromite fines could be obtained. The mechanism and influence factors for the solid carbothermic reduction of chromite are concluded. The influential factors include reduction temperature, reduction time, types of reductant, gas flow rate, size of particle and pellet, and additive species. This research would offer guidance for efficient utilization of low grade chromite fines. The research suggests that the influence of majority factors on the solid carbothemic reduction of chromite is nonlinear, and optimum values are always able to be obtained. For this reason, choosing optimum process conditions is significant for improving product quality and reducing product costs.