Dissertation > Excellent graduate degree dissertation topics show

A Study of the Metastable Phase Equilibrium for Quinary System Li+、Na+、K+//SO42-、B4O72--H2O at 273K

Author: LinXiaoFeng
Tutor: ZengYing
School: Chengdu University of Technology
Course: Chemical processes
Keywords: metastable equilibrium sulfate borate solubility Pitzer equation
CLC: O642.42
Type: Master's thesis
Year: 2008
Downloads: 102
Quote: 0
Read: Download Dissertation

Abstract


In order to develop the resource in the zabuye saline lake,Tibet, An experimental study on metastable equilibria at 273 K in the quinary system Li+, Na+, K+//SO42-, B4O72--H2O and four quaternary and three ternary sub-systems was done by isothermal evaporation method. Metastable equilibrium solubilities and density of the solution were determined. According to the experimental data, the metastable equilibrium phase diagram and the density-composition diagram and the water-content diagram were plotted.The results show that the double salt KLiSO4 and 3Na2SO4·Li2SO4·12H2O are formed in the quinary system Li+, Na+, K+//SO42-, B4O72--H2O. The metastable phase diagram has six invariant points, eighteen univariant curves, eight fields of crystallization which are Na2B4O7·10H2O, Na2SO4·10H2O, Li2SO4·H2O, LiBO2·8H2O, K2SO4, K2B4O7·4H2O, KLiSO4 and 3Na2SO4·Li2SO4·12H2O. The crystallization fields of lithium, sodium and potassium borate minerals are larger but the salt Li2SO4·H2O and the double salt 3Na2SO4·Li2SO4·12H2O are smaller. This feature is very important to extract lithium and borate from the salt lake brine.The double salt 3Na2SO4·Li2SO4·12H2O and KLiSO4 were also founded in the simple quaternary system Li+, Na+, K+//SO42--H2O. The simple quaternary system has three invariant points and seven univariant curves. The salt Li2SO4·H2O has the smalle st crystallization field, but the salt Na2SO4·10H2O has the biggest crystallization field. In the Li+, Na+//SO42- B4O72--H2O system, the double salt 3Na2SO4·Li2SO4·12H2O was formed. Its metastable phase diagram consists of three invariant points, seven univariant curves and five fields of crystallization. The salt Li2SO4·H2O has the small-est crystallization field, but the salt Na2B4O7·10H2O has the biggest crystallization field. compared with the phase diagram at 288 K, crystallization field and crystallizat-ion form change obviously, so we make use of phase diagram in the different temperature to get product. The quaternary system Na+, K+//SO42-, B4O72--H2O is of the simple type, it has two invariant points, five univariant curves and four crystallization fields, The salt Na2B4O7·10H2O has the biggest crystallization field. The salt Na2B4O7·10H2O and K2SO4 are stable salt in the quaternary system at 273 K. The double salt KLiSO4 was formed in the system Li+, K+//SO42-, B4O72--H2O. The metastable phase diagram consists of three invariant points, seven univariant curves and five crystallization fields, The salt LiBO2·8H2O has the biggest crystallization field. The borate salt is very complicated in the solution, the salt Li[B(OH)4]·6H2O formation mechanism also need a further research.Pitzer’s theory is used in high concentration multicomponent water-salt systems. Using the solubility of the ternary and quaternary systems, the single salt parameters of Na2SO4, Na2B4O7, K2B4O7, K2SO4, Li2SO4 and Li2B4O7, the solid-phase equilibrium constant and the mixing parameters were getted by the multiple linear regression method. Using the Pitzer’s equation, the solublities of the quinary system and invariant points of sub-system were calculated. The calculated values are good agreement with experimental results. The borate salt system calculation also need further research and find out the accurate distribution in the solution. this system is a high concentration multicomponent water-salt systems, so using the Pitzer’s equation will be difficult.

Related Dissertations

  1. Capsaicin / β - cyclodextrin system to dissolve and penetrate the,R943
  2. Characterization and Properties of capsaicin / CD system,TQ450.1
  3. The Study of Yeast Frost-resistance and Application in Frozen Dough,TS213.2
  4. The Research on the Comprehensive Modification Technology of Rice Protein Enzymatichydrolysis and Graft Copolymerization,TS201.2
  5. Modification and Application of the Waste Fluorgypsum and the Treating of High Concentrations Fluoride Wastewater,X703
  6. Studing on Water-holding Capacity and Its Controlling Methods of Fresh Chicken Meat,TS251.55
  7. The Research on the Modification and Functional Properties of Rice Glutelin,TS201.21
  8. Dewatering and Aerobic Composting of Cyanobacteria from the Taihu Lake,S141.4
  9. Roles of MMP-7 and Lysozyme in the Pathogenesis of Ulcerative Colitis Induced by DSS in Balb/c Mice,S858.91
  10. Research on the Effects of Magnesium Sulfate in Intervening Early Patients with Acute Cholangitis,R657.4
  11. Studies on the Dissolution of Chitosan in Ionic Liquids,O636.1
  12. Mouse anti-human PD-L2 monoclonal antibody and the human soluble PD-L2ELISA kit for,R392
  13. Rhubarb , magnesium sulfate treatment of severe acute pancreatitis comparative study of the clinical efficacy,R576
  14. Infrared spectroscopy surfactant aqueous two- phase system of,O647.2
  15. Augmentation of Sheep Vertebral Defect with BCP/CSH/SF/rhBMP-2: An in Vivo Study,R-332
  16. The high fill SSP material PVC - based flexible sound insulation composite materials,TB34
  17. Study on the Effect of Calcium Sulfate on Coal Ash Fusion Temperature,TQ533
  18. Optimum to the Electrolyte Composition of New Titanium Smelting Method and Its Application to Titanium Alloy Materials,TG171
  19. Characteristics of synthesis of poly- p-phenylenediamine and its adsorption of sulfate ions,X703
  20. Purification of an Estrogen Receptor from Carp and the Interaction with Phthalic Acid Esters (PAEs),S917.4
  21. Study of Microbial Corrosion in Central Air-conditioning Cooling Water System,TU831.4

CLC: > Mathematical sciences and chemical > Chemistry > Physical Chemistry ( theoretical chemistry ),chemical physics > Chemical thermodynamics, thermochemistry, thermodynamic equilibrium > Thermodynamic equilibrium > Phase Equilibria
© 2012 www.DissertationTopic.Net  Mobile