Research Of Recycled Salt And Glauber’ Salt Precipitation Rules Of Yabulai Salt Lake Brine

Yabulai salt lake is located in the Inner Mongolia plateau, dry windy and hot in summer, long and cold and big temperature difference between day and night in winter. we can take advantage of the local climate conditions to produce recycled salt and glauber’s salt. The main production of the salt lake was original salt and recycled salt before. After many years of production, glauber’s salt and magnesium salt are concentrated in brine now. It could affect the quality of the salt. So the change of the salt lake extensive production model, comprehensive utilization and sustainable development is the inevitable trend for the future development of salt lake. Aiming at local climate characteristics, this paper studied recycled salt and sodium sulfate precipitation rules of Yabulai salt lake brine, and determined the production process control parameters.First, with the aid of equilibrium phase diagram of the quaternary system (Na+, Mg2+//Cl", SO42--H2O), this paper studied the the rules of recycled salt precipitation under different temperature of brine salting, found that the main reason affecting the quality of regenerated salt was glauber’s salt enrichment. At20℃, glauber’s salt began to precipitate when the density of the brine reach1.2635g/cm3, precipitation rate of NaCl at this time was68.53%. At25℃, glauber’s salt began to precipitate when the density of the brine reached1.2619g/cm3, precipitation rate of NaCl was68.53%. When the temperature of the brine was35℃, glauber’s salt began to precipitate when the density of the brine reached1.2611g/cm3, precipitation rate of NaCl was64.39%at this time.Second with the help of equilibrium phase diagram of the quaternary system (Na+, Mg2+//Cl-, SO42--H2O), this paper studied the rules of glauber’s salt precipitation in the simulation of the local climate conditions and the results showed that that temperature had a great influence on the precipitation rate of glauber’s salt brine. Under the condition of constant temperature, low temperature is advantageous to the precipitation of glauber’s salt. At-10℃, when the rate of adding water was controlled at7.82%, concentration of SO42-fall below0.15mol/L in the liquid phase and glauber’s salt precipitation rate could reach82.61%. It could satisfy the requirements of the salt lake. Simulating the salt lake local climate characteristics, we can find that concentration of SO42-increased with the promotion of temperature. At-10℃, concentration of SO42-reached0.12mol/L, glauber’s salt precipitation rate was85.66%in this case. Concentration of SO42-in liquid phase was lower Compared with the condition of constant temperature at-10℃. Concentration of SO42-in liquid phase reached O.llmol/L at-10℃when the temperature changed from5℃to-20℃and meet the demand of the salt lake once again.In the process of production in yabulai, Salt Lake City need to control the concentration of salt lake brine according to the local climate characteristics, to ensure the production and quality of NaCl and glauber’s salt. In the freezing process in winter, the effect of temperature changes on SO42-ion concentration should be payed special attention.