氯化钙对碳热还原重晶石转化率影响的试验研究

Study on the Effect of Calcium Chloride Additive on Barite Reaction of Carbothermal Reduction

在重晶石和煤粉高温焙烧还原过程中添加一定量的氯化钙,运用热力学计算软件HSC计算不同温度下氯化钙在还原反应体系可能发生的反应的摩尔吉布斯自由能和焓变,分析其与温度之间的关系。通过焙烧温度、焙烧时间、添加剂用量等一系列条件实验,确定最适宜工艺条件:焙烧温度为1100℃、焙烧时间为90 min、氯化钙用量为重晶石的1%。在此条件下,黑灰中水溶性钡提高6.09%,酸溶性钡减少19.82%,重晶石转化率提高4.54%。

A certain amount of calcium chloride is added to coal and barite during roasting reduction with high temperature.The reaction Gibbs free energy,entropy change of the possible reaction of calcium chloride in the reduction reaction system at different temperatures was calculated by using HSC chemical thermodynamic calculation software,and analyzed the relationship between the thermodynamic parameters and temperature.Through a series of condition experiments such as roasting temperature,roasting time and additive dosage,the most suitable process conditions were determined as follow:roasting temperature of 1100℃,roasting time of 90 min,and the dosage of calcium chloride of 1%of barite.The results showed that the water-soluble barium in black ash was increased by 6.09%,the acid soluble barium was reduced by 19.82%and the barite conversion was increased by 4.54%.