铬铁矿液相氧化的热力学分析

THERMODYNAMICAL ANALYSIS ON THE PROCESS OF LIQUID-PHASE OXIDATION OF CHROMITE

液相氧化法生产铬酸盐技术是对传统火法焙烧技术的突破．在600～900K温度范围内对液相氧化法处理铬铁矿的熔盐体系各反应趋势及物相组成的热力学进行了分析研究，对液相氧化法处理铬铁矿各体系的反应自由能变化（△G°R）与温度（T）关系的计算结果表明，铬铁矿中的（Mg,Fe）（CrO2）2在较低温度下与NaOH、O2具有较强的反应趋势，比传统的火法焙烧方法反应温度降低了873K，节约大量能源;铬铁矿中的杂质相在反应温度下进行一系列副反应，生成硅酸盐、铝硅酸盐等新相．

The technology for producing chromic salt by the liquid phase oxidation process is a breakthrough over the conventional roasting process. The thermodynamic analysis on reactions occuring in the molten salt system of chromite in the liquid phase oaldation process at the temperature range of 600~900 K was carried out. The results of calculation on the relationship between free energy of reaction (△G°R) and temperature (T) for the chromite reactions in liquid-phase oxidation indicate that (Mg, Fe) (CrO2)2 shows strong reacting trend with NaoH and O2 at low temperature. In comparison with the conventional process, the reaction temperature may be decreased by 600 K and more energy is economized. During the liquid phase otidation, impurity in chromite undergoes reaction to produce some new phases such as silicate, alumininosilicate and so on.