Method for producing calcium chloride dihydrate

Abstract

The invention relates to a method for producing calcium chloride dihydrate, which is characterized by comprising the following steps: putting hydrochloric acid (31%) and limestone powder into a reaction vat according to the mixture ratio of 2.2:1, and stirring for reaction to generate an acid calcium chloride solution; transferring the obtained solution into a clarification tank, adding lime emulsion, regulating the pH value of the solution to 8.9-9 to precipitate out iron hydroxide and magnesium hydroxide; and transferring filtrate into an evaporation dish after clarifying and filtering, heating to the temperature of 172-174 DEG C, evaporating, drying and dewatering at the temperature of 200-240 DEG C after crystallizing and separating, to obtain the calcium chloride dihydrate. The invention has the following advantages of no pollution, high recovery rate and product cost reduction.

Description

technical field [0001] The present invention is a kind of production method of calcium chloride dihydrate Background technique [0002] Calcium chloride dihydrate is an important raw material for the manufacture of anhydrous calcium chloride. Anhydrous calcium chloride is widely used because of the following characteristics. It has the characteristics of heat generation and low freezing point when it meets water, and is usually used for snow melting and deicing of roads, highways, parking lots, and docks. It also has the function of strong water absorption, and can also be used as a desiccant, such as for the drying of nitrogen, oxygen, hydrogen, hydrogen chloride, sulfur dioxide and other gases. It is the best material for defog removal in ports, dust collection on road surfaces, and fabric fire prevention. Used as a dehydrating agent in the production of alcohols, esters, ethers and acrylic resins. Calcium chloride aqueous solution is an important refrigeration medium ...

AI Technical Summary

Problems solved by technology

[0003] Food-grade magnesium chloride is an important raw material for food additives, and its magnesium chloride content is required to reach more than 99%. At present, most manufacturers in my country have been using the traditional ammonia-alkali manufacturing process. The production of calcium chloride dihydrate by this process consumes a lot of heat energy and the product purity Not high, the equipment is severely corroded, so the cost of the product is high