真空铝热还原法制备金属Sr的热力学分析及实验研究

THERMODYNAMIC ANALYSIS AND EXPERIMENTAL RESEARCH ON PRODUCTION OF Sr USING VACUUM ALUMINOTHERMIC REDUCTION

通过热力学计算,得出SrO被Al还原的化学反应自由能和还原反应临界温度,表明造渣反应和真空可有效降低化学反应自由能,由此将还原反应临界温度由标准状态的2244 K降低到1100 K以下.热力学计算、反应产物X射线衍射分析及56%产Sr率测量结果均表明,真空铝热还原法制备金属Sr实际上同时发生了2个反应.反应产物除蒸馏出的金属Sr(纯度为99.0%)外,残留渣团主要为3SrO·Al2O3,并掺有SrO·Al2O3.

Based on thermodynamic analysis, the Gibbs free energy and critical temperature of the SrO deoxidized reaction by A1 has been calculated. It has been observed that the slagging reaction and vacuum can obviously lower the curves of Gibbs free energy versus temperature, the critical temperature was decreased from 2244 K to 1100 K below. Thermodynamic analysis, X-ray diffraction of the slag and measurement of the metal yield （56%） showed that the deoxide process can be described by the equations of 6SrO（s）＋2Al（1）=3Sr（g）＋3SrO·Al2O3（s） and 4SrO（s）＋2Al（1）=3Sr（g）＋SrO·Al2O3（s）. Pure metallic strontium （99.0%） has been prepared and the main compound in the slag is 3SrO·Al2O3 accompanied by SrO·Al2O3.