The solubility of MnSeO3-SeO2-H2O system was studied in the temperature region 25–300°C. The compounds of the three-component system were identified by the Schreinemaker’s method. The phase diagram of manganese(II) selenites was drawn and the crystallization fields for the different phases were determined. Depending on the conditions for hydrothermal synthesis, MnSeO3·H2O, MnSeO3·3/4H2O, MnSeO3·l/3H2O and MnSe2O5 were obtained. The different phases were proven and characterized by chemical, powder X-ray diffraction and thermal analyses, as well as IR spectroscopy. The kinetics of dehydration and decomposition of MnSeO3·H2O was studied under non-isothermal heating. Based on 4 calculation procedures and 27 kinetic equations, the values of activation energy and pre-exponential factor in Arrhenius equation were calculated for both processes.
研究了MnSeO3-SeO2-
H2O系统在25至300°C温度范围内的溶解度。通过Schreinemaker方法识别了三元系统的化合物。绘制了二价
锰硒酸盐的相图,并确定了不同相的结晶领域。根据
水热合成的条件,获得了MnSeO3· 、MnSeO3·3/4 、MnSeO3·1/3 和MnSe2O5。通过
化学、粉末X射线衍射、热分析及红外光谱等方法对不同相进行了证实和表征。研究了MnSeO3· 在非等温加热条件下的脱
水和分解动力学。基于4种计算程序和27个动力学方程,计算了两种过程的阿伦尼乌斯方程中的活化能和前指数因子的值。