Determination and Calculation of Phase Equilibrium for Tetrahydrofuran + Sodium Sulfate + Magnesium Sulfate + Water System at 5 掳C

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• 作者：Guo-En Li ; Ji-Lin Cao ; Pan-Pan Chen ; Bin Zhao
• 刊名：Journal of Chemical & Engineering Data
• 出版年：2013
• 出版时间：May 9, 2013
• 年：2013
• 卷：58
• 期：5
• 页码：1301-1307
• 全文大小：261K
• 年卷期：v.58,no.5(May 9, 2013)
• ISSN：1520-5134

文摘

In order to develop a new process for concentrating and separating sodium sulfate (Na₂SO₄) and magnesium sulfate (MgSO₄) of the bloedite based on tetrahydrofuran (THF) hydrate method, the equilibrium of the ternary systems THF鈥揘a₂SO₄鈥揌₂O and THF鈥揗gSO₄鈥揌₂O and the quaternary system THF鈥揘a₂SO₄鈥揗gSO₄鈥揌₂O were measured at 5 掳C, and the phase digrams of these three systems were investigated. It showed that the mass percentage of Na₂SO₄ (MgSO₄) in equilibrium liquid was higher than in feed and we could obtain Na₂SO₄路10H₂O and MgSO₄路7H₂O in turn. It proved that THF hydrate could be used to the concentration and separation of Na₂SO₄ and MgSO₄. The extended Pitzer model of the electrolyte鈥揺lectrolyte鈥搉onelectrolyte鈥搘ater system was derived and applied into THF鈥揘a₂SO₄鈥揗gSO₄鈥揌₂O system and its subsystems. The necessary thermodynamic parameters had been derived from a least-squares optimization program. The model calculation value was in good agreement with experimental solubility for ternary and quaternary mixtures, which indicated that the Pitzer model could be successfully used to predict the phase equilibrium of the electrolyte鈥揺lectrolyte鈥搉onelectrolyte鈥搘ater systems containning THF hydrate.