四元水盐体系KCl-NaCl-CaCl_2-H_2O蒸气压测定

Vapor Pressure Determination of Quaternary Water-Salt System KCl-NaCl-CaCl_2-H_2O

钢铁企业富钾烧结电除尘灰水浸液经脱除重金属杂质后可看作四元水盐体系KCl-NaCl-CaCl2-H2O,从该体系分离出氯化钾,需要首先通过蒸发浓缩及蒸发结晶。为了合理有效的控制蒸发操作过程,今采用静态法实验测定了四元水盐体系KCl-NaCl-CaCl2-H2O在KCl浓度为0～3 mol L 1,NaCl浓度为0～2 mol L 1,CaCl2浓度为0～1 mol L 1,温度为303.15～373.15 K的蒸气压,并通过数学线性回归得出了该体系的蒸气压与温度和体系组成的关系式,该关系式的获得有望为实际蒸发操作过程控制提供理论依据。

Water leaching solution of electro-static precipitator dust of sinter plant in iron and steel companies, which contains abundant potassium resource worthy to be paid attention to, can be taken as quaternary water-salt system KC1-NaCl-CaCl2-H2O after removal of heavy metal ions. Potassium chloride can be preliminarily separated from this quaternary system by ev,aporation concentration and evaporation crystallization. In order to provide a theoretical basis for controlling the separation process, the vapor pressures of the quaternary water-salt system KCI-NaCI-CaCI2-H20 with concentration of KC1, NaCl and CaCI2 in the range of 0-3 mol.L-1, 0-2 mol.L-1 and 0-1 mol.L-1, respectively, and temperature range of 303.15-373.15 K, were experimentally determined by static method for the first time. The dependence of vapor pressure of the quaternary water-salt system on temperature and solution composition was obtained by mathematical linear regression, which is expected for the instruction of the evaporation process.