In order to establish the theortetical basis and optimize the production conditions for the separation process of the H3BO3-MgSO4 mixed solution by using Mg（NO3）2 as the salting out agent.The phase diagrams of H3BO3...In order to establish the theortetical basis and optimize the production conditions for the separation process of the H3BO3-MgSO4 mixed solution by using Mg（NO3）2 as the salting out agent.The phase diagrams of H3BO3─MgSO4─Mg（NO3）2─H2O system at 25℃ and 100℃ were studied.The results show that there appear MgSO4·7H2O,MgSO4·6H2O,Mg（NO3）2·6H2O and H3BO3 three crystallization regions in the phase diagram at 25℃,and three crystallization regions of MgSO4·H2O,Mg（NO3）2·2H2O,and H3BO3 at l00℃.When the temperatures rise from 25℃ to 100℃,the crystallization regions for magnesium sulfate hydlates grow larger and while that of H3BO3 get smaller.Only MgSO4·4H2O could be crystallized out alone,if evaporating the H3BO3─MgSO4 solution in the presence of Mg（NO3）2.On cooling the MgSO4 mother liquor,H3BO3 can be separated alone without any addition of water.展开更多
文摘In order to establish the theortetical basis and optimize the production conditions for the separation process of the H3BO3-MgSO4 mixed solution by using Mg（NO3）2 as the salting out agent.The phase diagrams of H3BO3─MgSO4─Mg（NO3）2─H2O system at 25℃ and 100℃ were studied.The results show that there appear MgSO4·7H2O,MgSO4·6H2O,Mg（NO3）2·6H2O and H3BO3 three crystallization regions in the phase diagram at 25℃,and three crystallization regions of MgSO4·H2O,Mg（NO3）2·2H2O,and H3BO3 at l00℃.When the temperatures rise from 25℃ to 100℃,the crystallization regions for magnesium sulfate hydlates grow larger and while that of H3BO3 get smaller.Only MgSO4·4H2O could be crystallized out alone,if evaporating the H3BO3─MgSO4 solution in the presence of Mg（NO3）2.On cooling the MgSO4 mother liquor,H3BO3 can be separated alone without any addition of water.
