本文選題：KH_2PO_4　切入點(diǎn)：KCl　出處：《寧夏大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：KH_2PO_4和K_2SO_4是鉀鹽工業(yè)的重要產(chǎn)品,廣泛應(yīng)用于工業(yè)、農(nóng)業(yè)、食品、制藥等行業(yè)。目前國內(nèi)外KH_2PO_4多采用中和法生產(chǎn),K_2SO_4多采用曼海姆法生產(chǎn)。溶劑萃取法是近些年新開發(fā)的鉀鹽生產(chǎn)工藝,具有能耗小,反應(yīng)條件溫和,產(chǎn)品純度高等特點(diǎn),具有廣闊的發(fā)展前景。但溶劑萃取法生產(chǎn)KH_2PO_4和K_2SO_4的工藝不穩(wěn)定、結(jié)晶產(chǎn)品品質(zhì)不高。鑒于以上現(xiàn)狀,本文在測定相平衡數(shù)據(jù)的基礎(chǔ)上,優(yōu)化結(jié)晶工藝,為工業(yè)優(yōu)化該工藝奠定基礎(chǔ)。首先,本文采用等溫溶解平衡法測定了298.15K、313.15K,K_2SO_4-KCl-H_2SO_4-H_2O和KCl-KH_2PO_4-H_3PO_4-H_2O四元體系及其三元子體系的固-液相平衡及物性參數(shù)(密度、黏度),KCl-KH_2PO_4-H_2O三元體系在不同濃度(10%,30%,50%)下的乙醇溶液中的固-液相平衡及物性參數(shù),繪制了相圖,溶解度圖,物性參數(shù)-組成圖。采用經(jīng)驗(yàn)公式對兩個(gè)四元體系及其三元子體系298.15K、313.15K平衡液相的溶解度、密度和黏度進(jìn)行了模擬計(jì)算。結(jié)晶工段作為重要的除雜步驟,優(yōu)化冷卻結(jié)晶工藝條件,探究雜質(zhì)和溶析劑乙醇對KH_2PO_4結(jié)晶的影響至關(guān)重要。本文圍繞制備高品質(zhì)KH_2PO_4展開研究,考察了各工藝參數(shù)對KH_2PO_4結(jié)晶工藝的影響。獲得最佳工藝條件為:攪拌速率300r/min,降溫速率0.25℃/min,陳化時(shí)間30min,晶種質(zhì)量1.01%,晶種目數(shù)100目。由于原料濕法磷酸中含有多種微量雜質(zhì)離子,且雜質(zhì)離子對KH_2PO_4晶核的生成及生長影響較大,因此,本文研究了摻雜兩種含量不同的金屬離子對KH_2PO_4結(jié)晶的影響。本文的研究成果為溶劑萃取法生產(chǎn)KH_2PO_4和K_2SO_4提供了基礎(chǔ)數(shù)據(jù),并為生產(chǎn)高品質(zhì)KH_2PO_4等鉀鹽奠定了基礎(chǔ)。
[Abstract]:KH_2PO_4 and K2SO4 are important products in the potash industry and are widely used in industry, agriculture, food, At present, KH_2PO_4 mostly uses neutralization method to produce K _ 2SO _ 4 by Mannheim method. Solvent extraction is a newly developed potassium salt production process in recent years, which has the characteristics of low energy consumption, mild reaction conditions and high purity of the product. The process of producing KH_2PO_4 and K _ 2SO _ s _ 4 by solvent extraction method is unstable and the quality of crystallization product is not high. In view of the above situation, the crystallization process is optimized on the basis of the determination of phase equilibrium data. First of all, the isothermal dissolution equilibrium method was used to determine the solid-liquid equilibrium and physical properties (densities) of the four component systems and their ternary subsystems of KCl-KH_2PO_4-H_3PO_4-H_2O and the KCl-KH_2PO_4-H_3PO_4-H_2O quaternary systems, which were determined by isothermal dissolution equilibrium method, and the isothermal dissolution equilibrium method was used to determine the solid-liquid equilibrium and the physical properties (densities) of the four component systems and their ternary subsystems. The solid-liquid equilibrium and physical parameters of the KCl-KH2PO4-H _ 2O ternary system in ethanol solution with different concentrations of 10 and 30 and 50. The phase diagram and solubility diagram are drawn. The solubility, density and viscosity of two quaternary systems and their ternary system 298.15K ~ 313.15K equilibrium liquid phase were simulated and calculated by means of empirical formula. As an important impurity removal step, the crystallization section was used to optimize the cooling crystallization process conditions. It is very important to explore the effect of impurities and ethanol on the crystallization of KH_2PO_4. This paper focuses on the preparation of high quality KH_2PO_4. The effects of various technological parameters on the crystallization of KH_2PO_4 were investigated. The optimum conditions were obtained as follows: stirring rate 300r / min, cooling rate 0.25 鈩，

本文編號：1556555