Isotherme à 25°C du Système Quaternaire Réciproque H3PO4?K2SO4?H2SO4?K3PO4?H2O Etude des Nappes du Liquidus |
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Authors: | Nji Bourguiba Tahar Jouini |
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Institution: | Néji Bourguiba,Tahar Jouini |
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Abstract: | 25°C Isotherm of the Reciprocal Quaternary System H3PO4? K2SO4? H2SO4? K3PO4? H2O Study of the Liquidus Curves The liquidus of the reciprocal system H3PO4? K2SO4? H2SO4? K3PO4–H2O has been investigated as a last step in the determination of the equilibrium diagram at 25°C and 1 atm pressure. Solubility has been detected by conductometric measurements in isopletic sections selected in order to complete the data obtained from the limiting ternary systems and the previously found boundary curves. Four isopletic sections have been completely established: K2SO4? KH2PO4, K2SO4? K2HPO4, KHSO4? K2HPO4 and KHSO4? KH2PO4. The two first ones are quasi ternary systems. Nine portions have been studied and the curves of equal water content plotted. The liquidus of KHSO4, K8(H2PO4)1+x(HSO4)7?x and KH2PO4 · KHSO4, show a rotationel shape which reveals a retrosolubility depending on the water content. |
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Keywords: | Phosphoric acid – sulfuric acid system potassium phosphate salts phosphosulfuric salts |
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