THE NON-EQUILIBRIUM SALT FORMING PHASE DIAGRAM: APPLICATION TO EFFECTIVELY UTILIZE BRITTEN RESOURCE

摘要

The non-equilibrium state salt forming phase diagram, include primary region and extended Region, are different from solubility phase diagram and metastable phase diagram, which can be used to express the salt forming regions in the non-equilibrium state of evaporation and crystallization process in the high temperature for the multi-component salt-water systems. In this paper the residual brine resource of Tulantai salt-lake(China), Dongtai Salt-lake(China), Jilantai Salt-lake(China), Qarun Salt Lake(Egypt) and Seawater which after precipitation of pure sodium chloride, was analyzed. The benefit strategy needed by bittern utilization was given by compare 'Na2SO4 based plan' with 'MgSO4 based Plan'. The operations required by evaporation processes at 25°C, 75°C, 100°C and 150°C were simulated by a path through the solubility diagram and salt-forming diagram of Mg2+-Na+//SO42--Cl--H2O system. The yield and recovery rate of salt and sulfate were calculated. The results show, (1) more benefit of MgSO4 based plan than that of Na2SO4 based plan. (2) MgSO4 based plan can be putted in practice, but in the middle temperature and vacuum evaporation process. (3) the yield of NaCl for the several bittern in the MgSO4 based plan were 1.53,2.01,2.95,19.48 and 6.8 times respectively than that of Na2SO4 based plan in the normal temperature, the recovery rate of sulfate were increased by 18.46%, 27.51%, 38.23%, 55.13% and 79.99% respectively.