铁渣的微波干燥过程及机制研究

Study on Microwave Drying Process and Mechanism of Iron Scum

在分析原料主要物相组成和元素分布状态的基础上,对微波干燥过程的机制进行了深入分析。采用热重和热干燥分析方法确定了铁渣中水分存在形式,并对原料的高温介电特性和影响微波干燥的主要因素进行了探究。研究结果表明,铁渣含有结晶水的物相为CaSO_(4)·0.5(H_(2)O)和CaH(AsO_(4))·2H_(2)O,自由水含量为17.6%,结晶水含量为11.1%,自由水含量高于结晶水,微波干燥具有优势。微波干燥的最佳技术参数为:微波加热功率900 W,干燥时间90 s,物料厚度1.5 cm,此时,温度为93℃,主要为自由水的脱除,脱水率为18.42%。微波干燥比同等程度常规干燥节约91.67%时效。

The drying process of iron scum under microwave condition is studied,the mechanism of microwave drying process is analyzed deeply on the basis of analysis of major phase composition and element distribution state.Thermogravimetry and thermal drying analysis method was adopted to confirm the existing form of moisture of iron scum,main factors for high temperature dielectric properties and microwave drying of raw ore were studied.Study results show,the phase of iron scum with crystallization water is CaSO_(4)·0.5(H_(2)O)and CaH(AsO_(4))·2H_(2)O,the free water content is 17.6%,crystallization water content is 11.1%,the cotent of free water is higher than crystallization water,microwave drying has advantages.The best technical parameters of microwave drying are:microwave heating power is 900 W,drying time is 90 s,material thickness is 1.5 cm,then the dehydration rate is 18.42%,temperature is 93℃,free water was removed mainly.Microwave drying is more economical than conventional drying to the same extent,it saves about 91.67%aging.