Solid-liquid Phase Equilibrium Of Quaternary System Ca²⁺?Mg²⁺//SO₃^2-?SO₄^2--H₂O And Phase Equilibrium Simulation Of Related Salt-water System

Seawater Flue Gas Desulfurization?FGD?is a kind of technology with high utilization rate,simple process,clean and environmental protection.Because of the ability of weak alkaline and acid buffering capacity,seawater can effectively absorb sulfur oxides in flue gas and convert into insoluble calcium salt and magnesium salt.Accordingly,the study on quaternary system Ca²⁺?Mg²⁺//SO₃^2-?SO₄^2--H₂O is of great significance for the deep comprehension of seawater desulfurization.In this paper,the solid-liquid equilibrium of quaternary system Ca²⁺?Mg²⁺//SO₃^2-?SO₄^2--H₂O systems at 25?was studied by isothermal solid state method.The results show that there are five crystalline regions of CaSO₃·0.5H₂O,Ca?SO₃?_0.89?SO₄?_0.11·0.5H₂O,CaSO₄·2H₂O,MgSO₃·6H₂O and MgSO₄·7H₂O)and three invariant points?point of Csi,SS and Msh;point of Msh,Eps and SS;points of SS,Gyps and Eps?in this quaternary system.Based on Pitzer theory and HMW model as the theoretical basis for the calculation of phase equilibrium.The product activities of equilibrium solid phase expressed as a function of molality.On analyzing data of quaternary system and ternary sub-systems Ca²⁺?Mg²⁺//SO₃^2-?SO₄^2--H₂O,ion interaction parameters regressed.The consequence illustrates that the calculated values agree well with the experimental values.At present,the common program of phase equilibrium calculation written in FORTRAN,which has advantages of high efficiency and strict grammar.Nevertheless,it does not have intuitive graphical interfaces.What's more,one program can only calculate specific system and basis of programming is required.This is why these applications are difficult to promote.In this paper,based on Windows development environment,using Visual Studio 2015Community and natively support Visual Basic,developed an UWP platform program,called CSLPE,for calculating simple ternary system with Pitzer theory and HMW model.The program can easily install on any Windows Phone,Surface,X-box and Hub devices,which has the advantages of an intuitive interface,easily to operate and open source.