The Study Of Preparation,Characterization And Associated Phase Diagrams Of Engel Double Salt Crystal

This thesis mainly studies the physical and chemical properties of Engel double salt,we design to use the conclusions that we get from all the studies.The conclusions are used into the process of Engel correlation properties,in order to increase its presence in salt producing of potassium carbonate by experiments yield,and to improve the yield of potassium carbonate.Through the low temperature hydrothermal synthesis experiments of Engel double salt crystal structure characterization,we summarize the synthesis rules and synthesis conditions,we also further define the Engel double salt formation mechanism;Through the laboratory determinations.we drew the associated salt water phase diagrams.There are ternary system and quaternary system phase equilibrium of Engel double salt,which are draw by the study on phase diagram.We study the producing process of potassium carbonate by some experiments,we fing that there are various reactants ratio,concentration, reaction conditions and other factors impact the formation process of Engel double salt.After this,the use of phase diagrams of Engel double salt to guide the producing process of potassium carbonate on experiments.The results show that:In the preparation of Engel double salt crystal,we can use39g of the potassium hydrogen carbonate,0.2g of basic magnesium carbonate,which are dissolved in100ml deionized water;Cooling crystallization so that the temperature can be reduced from40degrees to25degrees centigrade.The whole process is kept for about7hours,then we can obtain the crystal,which appearance is the best,which transparency is the best.We can also observe the crystal easily,The Engel double salt’s purity is also relatively high.The methods of drawing the ternary system and quaternary system phase equilibrium of Engel double salt are accurate and reliable.Laboratory determinations of the solubility and reliable data are accurate,the phase diagrams have the meaning of reference value.In the experiment, the reactant initial concentration of potassium chloride is configurated at about4mol/L,in the reaction process we also use the method of cooling to dilute crystallization.Continuous reactions are needed until approximately5times are finished at last.We also need to strictly control the pH during7-9.With all the above methods,we can improve the potassium chloride’s conversion rate at last.