Salt's Forming Regions In Non-Equilibrium State Of Boiling-Evaporation Process Of Na⁺,Mg²⁺//Cl^-,SO₄^2--H₂O System At 100℃

Salt-water system phase diagram include the thermodynamic equilibrium phase diagram,metastable phase diagram and thermodynamic non-equilibrium phase diagram. Some expeimental results in high temperature and boiling evaporating process differed from the thermodynamic equilibrium phase diagram,metastable phase diagram. For the different system, variety extent will be changed. Considering that such relations exist in the non-equilibrium process, therefore study the salt-water system phase relations in high temperature and boiling evaporating process by the theory of non-equilibrium thermodynamics and crystallization kinetics.This study was the boiling evaporating experiments using co-saturated equilibrium solution of Na⁺,Mg²⁺//SO₄^2-—H₂O ternary system, get the salt-forming regions of non-equilibrium stable phase diagram and non-equilibrium metastable phase diagram in boiling evaporating process.This study also did the boiling evaporating experiments using co-saturated equilibrium solution of Na⁺,Mg²⁺//Cl^-,SO₄^2-—H₂O quaternary system. Acording to the experimental results, get the salt-forming limit of Na₂SO₄,Van,Low,M1 and NaCl and the NaCl regions of non-equilibrium stable phase diagram and non-equilibrium metastable phase diagram in boiling evaporating process.The experimental results show that the salt-forming regions and character of Na⁺,Mg²⁺//SO₄^2-—H₂O ternary system & Na⁺,Mg²⁺//Cl^-,SO₄^2-—H₂O quaternary system was different from the thermodynamic equilibrium phase diagram and metastable phase diagram. For the different salt, the non-equilibrium salt-forming region acount various ratio. Different impetus of salt-forming in the non-equilibrium processes caused the change. The supersaturation is different from primary salt-forming to salt-forming in boiling evaporating non-equilibrium state.