Method of preparation of potassium carbonate

Abstract

The invention discloses a method of preparation of potassium carbonate. The method is characterized by comprising the steps of 1, a primary brine refining; 2, a secondary brine refining; 3, upper potassium solution preparation; 4, Ion exchange reaction; 5, elution reaction; 6, resin regeneration reaction; 7, evaporation concentration; 8, spray granulation. According to the method for preparation of potassium carbonate, natural mineral salt is directly used as raw material, the raw material is not only low in cost but also suitable for industrial production, and the potassium ion-exchange rate can be increased by the method of preparation, the entire production process is simple and environmentally friendly, and waste ammonia is recycled.

Description

technical field [0001] The invention relates to a preparation method of potassium carbonate. Background technique [0002] Potassium carbonate is an important inorganic chemical basic raw material. It was successfully developed and put into industrial production in my country in the early 1970s. At that time, it was mainly used in the purification of synthesis gas in ammonia synthesis plants, and it could also be used as chlorine-free potassium fertilizer. The demand was small, 80 Since the 1990s, the demand for potassium carbonate in my country has grown rapidly, and its applications have become increasingly widespread: it is widely used in the chemical industry as a decarburizer for fertilizers, as a scavenger for hydrogen sulfide and carbon dioxide in industrial gases; as an anti-aging agent for rubber; in the glass industry. Manufacture computer monitors, TV picture tube glass bulbs, electron tubes, precision glassware and various decorative special glasses; it is a good c...

AI Technical Summary

Problems solved by technology

The plant ash method is the oldest method, that is, it is extracted from the plant ash burned from various plant shells (such as cottonseed shells, tea seed shells, tung nut shells, and sunflower shells). Plant ash contains potassium carbonate, potassium sulfate, potassium chloride and other soluble substances. Salt can be separated by precipitation and filtration. This method is rarely used due to the low quality of the product, uneconomical, and limited by the source of raw materials; the Lublin method is to mix potassium sulfate with coal powder and lime, and reduce and roast it to obtain Black ash (including burned products such as potassium carbonate and calcium sulfide) is leached, filtered, evaporated, and carbonized to obtain potassium bicarbonate, which is then filtered and calcined to obtain the product. This method has been replaced by other methods due to the long process flow and other reasons. Replaced; the electrolysis method is to use the potassium hydroxide solution obtained after the electrolysis of potassium chloride, carbonize it with carbon dioxide in a carbonization tower, evaporate and filter it in a multi-effect evaporator to obtain potassium bicarbonate, and then calcinate to obtain the product. The raw materials are easy to obtain, the utilization rate of potassium is high, and there is no three wastes, so it has been widely used, but it consumes more power, requires high equipment, and the investment in ion membrane electrolyzer equipment is large, and the capital recovery period is long, resulting in high product costs; The exchange method is to exchange the cation exchange resin with potassium chloride, and then elute with ammonium bicarbonate to form a dilute solution of potassium bicarbonate, and then obtain the product through multi-effect evaporation, carbonization, crystallization, separation and calcination. The product quality of this method is good, and the process flow Short, but only suitable for small-scale production, the raw material potassium chloride is usually chemically pure or industrially pure, the cost is high, and because the cation exchange resin often uses sodium-type ion exchange resin, there will also be resin exchange capacity and exchange rate of potassium ions Not high, the amount of potassium chloride is large, the consumption is large, etc.

Images