Eight Water Strontium Hydroxide Dry

Experiments of Si(OH)2-8H2O drying by microwave heating and conventional electric heating were studied in this paper, and a comparison of the results by these two methods was made. The influences of main effects on the relative dehydration rate of Si(OH)2·8H2O were investigated. Conditional electrical heating kinetic model and microwave heating kinetic model were obtained, too.Experiments of Si(OH)2·8H2O drying by conventional electric heating show that the Si(OH)2·8H2O relative dehydration rate increases with increasing the drying temperature, the material thickness and the drying time and it drops slightly with increasing the materials mass. Si(OH)2·8H2O drying by conventional electrical heating can be divided into the first rapid heating constant drying period, deceleration phase and the second period of slow drying speed. Conventional electrical heating experiments of four factors and five levels were accomplished by use of Design-Expert7 software. The experimental results and the Design-Expert7 software analysis showed that the drying temperature, the material thickness and the drying time are the main factors. The relational formula between Si(OH)2·8H2O relative dehydration rate and the conditions were also obtained.Experiments of Si(OH)2·8H2O drying by microwave heating showed that:the use of microwave heating to dry Si(OH)2·8H2O is feasible; the Si(OH)2·8H2O relative dehydration rate increases with increasing the microwave power, increases significantly with decreasing the material thickness, increases with increasing the microwave heating time, decreases with increasing the materials mass.Furthermore, the conventional electrical heating drying method was compared with microwave heating drying method. The microwave drying time is 1/40 less than that of conventional electrical drying. XRD spectra showed that Si(OH)2·8H2O transforms into Si(OH)2 completely by microwave drying, since no Si(OH)2·8H2O characteristic peak exists while the peaks remain in conventional electrical heating case. This shows microwave heating drying is better than conventional electrical heating drying. The Si(OH)2·8H2O drying kinetics study showed that conventional electric heating drying model and microwave drying model of thin layer of Si(OH)2 can be used to describe the exponential model.