What is the production process of ammonium chloride?

There are two main production processes for ammonium chloride: one is to use the Hou's alkali method invented by the famous Chinese scientist Hou Debang, and to produce both soda ash and ammonium chloride; the second is to produce by-products such as potassium carbonate. Ammonium chloride is prone to agglomeration and is usually added by an anti-caking agent to prevent product agglomeration.

Food grade ammonium chloride is a colorless crystal or white granular powder, odorless. The taste is salty and bitter. It has low hygroscopicity, but it can also absorb moisture and agglomerate in wet and rainy weather. Powdered food grade ammonium chloride is very easy to absorb moisture, especially wet ammonium, the moisture absorption point is generally about 76%. When the relative humidity in the air is greater than the moisture absorption point, the food grade ammonium chloride will absorb moisture and easily agglomerate. Can sublimate without melting point. The relative density is 1.5274. Heat to 350 ° C sublimation, boiling point 520 ° C. Soluble in water, slightly soluble in ethanol, soluble in liquid ammonia, insoluble in acetone and ether.

1. Recrystallization method: the crude ammonium chloride is added to a dissolver, dissolved by steam, filtered, and the filtrate is cooled and crystallized, centrifuged, and dried to obtain an industrial ammonium chloride product. The centrifuged mother liquor is returned to the dissolver for use;

2. Metathesis method: firstly, the ammonium chloride mother liquor is added to the reactor and heated to 105 ° C, ammonium sulfate and salt are added, and the metathesis reaction is carried out at 117 ° C to form an ammonium chloride solution and sodium sulfate crystals, and the sodium sulfate is removed by filtration. The ammonium chloride saturated solution is sent to a cooling crystallizer, cooled to 32-35 ° C to precipitate crystals, filtered, and the crystals are respectively rinsed with four different concentrations of ammonium chloride solution to control Fe <0.008%, SO42-< 0.001%, after rinsing to pass, the crystals are re-pulped into a slurry with ammonium chloride solution, sent to a centrifuge for separation and dehydration, and then dried by hot air to obtain an industrial ammonium chloride product. The mother liquor is sent to the metathesis reactor for recycling. The separated sodium sulfate is used for the production of Yuan Ming powder;