制备硅钢级氧化镁前驱体的原料水化研究

以青海盐湖水氯镁石为初级原料,采用喷雾热解法制备原料氧化镁,原料氧化镁通过水化制备硅钢级氧化镁前驱体氢氧化镁。原料氧化镁水化实验中对水化剂、水化温度、水化时间、液固比、搅拌速度及陈化时间对水化率、过滤速度和纯度的影响进行系统研究。采用均匀实验设计和DPS数据处理,(依次)通过建模分析、二次多项式模型回归建立数学模型,再通过各因素方差分析和总方差分析,确定了理论最优实验条件,再用理论最优条件作重复实验进行验证,最终确定了原料氧化镁的最佳水化条件。在水化温度60℃,水化时间105 min,液固比4,陈化时间4 h,水化剂1含量4.0%,水化剂2含量3.15%,洗水量4倍,搅拌速度120 r/min时,原料氧化镁的水化率达99.50%以上,得到的硅钢级氧化镁前驱体氢氧化镁纯度高、过滤性能良好。

Study on Hydration of Raw Material for Preparation Silica-steel MgO Precursor

By spray pyrolysis method,bischofite in Qinghai salt Lake,as primary raw material,was used to prepare precursor raw material MgO for silicon-steel MgO.The precursor raw material MgO was used for preparing Mg(OH)2 which was the precursor of silicon-steel MgO,by hydration method.In the hydration experiment of precursor raw material MgO,some experiment parameters were investigated systematically.such as the hydrated agent,the temperature and time of hydration,liquid/solid ratio that affected the hydration rate,rate of filtration and purity.The theoretical optimum conditions were obtained by uniform experimental design,DPS data processing,model analysis,quadratic polynomial regression model to establish the mathematical model,variance analysis of factorsa and the total variance analysis,and then,thetheoretical optimum conditions were verified by repeated trials:hydrationtemperature 60℃,hydration time105 min,liquid/solid ratio 4,ageing time 4 h,hydrated agentⅠ 4.0%,hydrated agentⅡ 3.15%,washing water 4,Stirring speed 120 r/min.Under the conditions mentioned above,the hydration rate of raw MgO reached over 99.50% and the prectlrsor Mg(OH)2 for silica-steel MgO has such advantages that high purity and good filtration performance.