Study On Process Scheme Of Evaporation Of Potassium Extraction In Concentrated Seawater

China's lack of supply of potassium resources depends on foreign imports for a long time,and China is an agricultural country with large demand for potash,and seawater is rich in potassium resources.The efficient extraction and extraction of marine potassium resources is still one of the directions for the development and utilization of potash resources.The seawater desalinated rich seawater is rich in potassium,and the separation of sodium and potassium salts is always involved in the process of extracting potassium from seawater.The selection of technical solutions for extracting potassium from concentrated seawater and the energy situation are discussed.The impact is still significant.Based on the Na Cl-KCl-H2 O phase diagram,based on the analysis of the separation process of sodium chloride and potassium chloride,this paper combines the requirements of the potassium chloride crystallization process on the temperature of the potassium chloride solution in the evaporation process.Based on the principle of determining the best effect of effective evaporation,a four-effect cross-flow evaporation model for the evaporation of potassium from Na Cl-KCl as the solute was established.According to the characteristics that the solubility of Na Cl-KCl-H2 O in the water-salt system phase diagram changes linearly,and the experimentally determined boiling point data of the mixed salt solution under different pressures,computer programming is used to simulate the evaporation process.A MATLAB program was written to calculate six four-effect cross-flow evaporation process solutions with solid-phase precipitation and two-effect discharge.The calculation results were analyzed economically and the optimal process scheme was IV-III-I-II.On the basis of the optimal process plan,the effect of the operating parameter steam pressure and the final vacuum on the evaporation system was investigated.The results show that the optimal operating parameters under this design condition are the two-effect discharge temperature of about 100? and the end.The efficiency of vacuum 80-90 k Pa,heating steam pressure of 260 k Pa ~ 270 k Pa.Based on the optimal four-effect cross-flow scheme,the effects of the suction position and the injection coefficient of the steam jet pump on the evaporation system were investigated.The results showed that the steam pressure was 800 k Pa,the two-effect pumping,and the injection coefficient were 0.45..Economic evaluation of the two MVR evaporation schemes,resulting in an optimal MVR evaporation scheme,and economic analysis with a four-effect cross-flow evaporation process with energy-saving measures,resulting in an MVR process superior to four in view of energy consumption Efficient cross-flow evaporation process.