微波加热高碳铬铁粉气-固相流化脱碳热力学研究

微波加热高碳铬铁粉流态化脱碳是一种简捷的无渣脱碳法，既能获得中低碳铬铁粉，又可避免有害铬渣的排放。高碳铬铁粉气-固相流化脱碳，气体脱碳剂的选择、气-固相流化脱碳热力学条件以及铬氧化热力学就成为试验研究的基础问题。热力学计算研究表明，微波加热温度分别高于298，1380和1435K时，气体脱碳剂O2、CO2、H2O（g）开始和高碳铬铁粉颗粒发生气-固相流化脱碳反应。由于脱碳生成的铬铁素体易被气体脱碳剂所氧化，使得脱碳反应由高碳铬铁粉颗粒表面的气-固相脱碳反应转变为颗粒内部的铬铁碳化物与铬铁氧化物之间的固一固相反应，从而可在一定的微波加热温度、流化时间下实现高碳铬铁粉的深度脱碳。

Study of Thermodynamics of Gas-Solid-Phase Fluidized Decarburization for High Content-Carbon Ferrochrome Powders by Microwave Heating

Fluidized decarburization of high content carbon ferrochrome powders （HCFP） in microwave field is a kind of simple method for no-residue decarburization, which can not only obtain medium/low content carbon ferrochrome powders, but also avoid emission of harmful chromic slag. For experimental research of gas-solid-phase fluidized decarburization of HCFP, the selection of gas decarburizer and thermo-dynamic conditions of gas-solid-phase fluidized decarburization as well as thermodynamics of chromium oxidation are the major issues. Thermodynamiccalculations show that when temperature of HCFP heated by microwave becomes higher than 298, 1380 and 1435 K, respectively, the reaction of gas-solid-phase decar- burization between the particle and gas decarburizers-O2, CO2 and H20（water vapor）- will in turn take place. As the chromium ferrite at the particle surface generated in the process of decarburization can be easily oxidized by the gas decarburizer, decarburization reaction from the gas-solid-phase,decarburization at the particle surface is transferred into the solid-solid-phase reaction between chromium-iron carbides and chromium-ion oxides inside the particles. As a result, deep decarburization of HCFP can be achieved at a certain temperatureof microwaveheating and period of fluidization time.