Production and grade requirements of anhydrous calcium chloride
Update time: 2013-07-25 Browse 3482 people
Anhydrous calcium chloride (CaCl2) is a white or off-white solid (granular, block or powder), slightly bitter in taste, odorless, easily soluble in water, and emits a lot of heat when dissolved in water. It has strong hygroscopicity and is easily deliquescent in the air, so it should be stored in a sealed airtight.

CaCl2 can be used as desiccant, dehydrating agent, refrigerant, antifreeze for aviation and automobile internal combustion engines, coagulation antifreeze, fabric fire retardant, food preservative, etc.

1. Production principle

It can be prepared by the reaction of limestone and hydrochloric acid. The main chemical reaction is as follows: CaCO3+2HCl→CaCl2+H2O+CO2↑

2. Operation process

1. Calcium chloride dihydrate (CaCl2· 2H2O): Put hydrochloric acid (31%) and limestone powder into the reaction tank at a ratio of 2.2:1, and react under stirring to form an acidic calcium chloride solution. In the clarification tank. Add lime milk to adjust the pH of the solution to 8.9-9. At this time, iron hydroxide and magnesium hydroxide precipitate out. After clarification and filtration, the filtrate is transferred in an evaporating dish and heated to 172～174℃ to evaporate. After crystallization and separation, it is dried and dehydrated at 200～240℃ to obtain calcium chloride dihydrate.

2. Preparation of anhydrous calcium chloride: reheat the dihydrate calcium chloride to 260～300℃, dry and dehydrate, then it will become white anhydrous calcium chloride.

Physical and chemical properties:

Colorless cubic crystal, white or off-white porous block or granular solid. The relative density is 2.15, the melting point is 782℃, the boiling point is above 1600℃, it is extremely hygroscopic, very deliquescent, easily soluble in water, and emits a lot of heat at the same time, odorless, slightly bitter taste, slightly acidic aqueous solution, soluble in alcohol, propylene Vinegar, acetic acid.

Product Usage:

It is a precipitant for the production of lake pigments. Production of desiccant for nitrogen, acetylene, hydrogen chloride, oxygen and other gases.

It is used as a dehydrating agent in the production of alcohols, ethers, esters and acrylic resins, and its aqueous solution is an important refrigerant for refrigerators and refrigeration. It can accelerate the hardening of concrete and increase the cold resistance of cement mortar. It is an excellent antifreeze. Used as a protective and refining agent for aluminum-magnesium metallurgy.

.Packaging, storage and transportation:

This product is packaged in a polyethylene compound plastic woven bag lined with two types of Chinese and English fonts, and four packaging specifications: 22kg, 25kg, 30kg, and 40kg.

This product should be stored in a ventilated and dry warehouse, handle with care when loading and unloading, to prevent damage to the package and moisture absorption

Technical indicators of anhydrous calcium chloride

Index name High-quality product First-class product Qualified product

Calcium chloride (CaCl2)% ≥ 96.0 95.0 90.0

Magnesium and alkali metal chlorides (as sodium chloride)% ≤ 2.0 2.5 2.5

Water insoluble ≤ 0.1 0.1 0.1

Alkalinity [Calculated as Ca(OH)2]% ≤ 0.1 0.1 0.1

Sulfate [Calculated as CaSO4] %≤ 0.05 0.1 0.1