由氯化钠和硫酸制盐酸和硫酸钠的研究

Study of the Preparation of Hydrochloric Acid and Sodium Sulfate from Sodium Chloride and Sulphuric Acid

氯化钠和硫酸在50℃～135℃下反应,生成NaHSO_4固体和HCl气体。NaHSO_4和NaCl在80℃～110℃下溶于水,再加入一种高沸点的有机溶剂作为盐析剂,使Na_2SO_4沉淀析出。固液分离后,晶体经洗涤、干燥得硫酸钠；含有机溶剂的盐酸溶液先后蒸出水和HCl。蒸出的水一部分返回系统,一部分和HCl气体生成稀盐酸。蒸发残液(含溶剂和少量钠盐溶液)再返回系统作盐析剂。用稀盐酸吸收HCl气体得盐酸。该工艺投资较少、能耗较低、成本低、产品质量好,经济效益好。

Sodium chloride reacts with sulphuric acid under 50℃ - 135℃ to produce sodium bisulfite （ NaHSO4 ） solid and hydrochloric acid（HCl） gas. Sodium bisulfite and sodium chloride are dissolved in water under 80℃ - 110℃, an organic solvent with high boiling point is added as an salting-out agent,then sodium sulfate salts out. After separating,cleaning and drying,sodium sulfate is obtained. Water and hydrogen chloride are evaporated from the hydrochloric acid solution. A part of the evaporated water goes back to the system ,the other part of the water absorbs hydrogen chloride to get muriatic acid. The remained solution after evaporating,which has the organic solvent and some sodium salts,goes back to the system as an salting-out agent. The muriatic acid absorbs hydrogen chloride to get hydrochloric acid. The advantages of this process are of low investment, low energy consumption, low cost ,high product quality, and good economic returns.