Calcium Chloride CACL2 process

Calcium Chloride (CaCl2) is an inorganic compound, marketed as 36% solution, 75-78% flakes or 94-97% granules, used for roads de-icing, dust control, brine refrigeration, dehumidification, setting time reduction in concrete, petroleum oil extraction and food processing.
Calcium chloride production process basically consists of limestone reaction with hydrochloric acid.
It can be also produced as by-product from Solvay process for soda ash and, only in the U.S., by the concentration and purification of naturally occurring brines from salt lakes and salt deposits.

Consito developed know-how and technologies for Calcium Chloride production units as 36% solution, 75-78% flakes or 94-97% granules, basing on reaction between limestone and hydrochloric acid.

Production process

Calcium chloride is produced as a product solution from reaction of calcium carbonate and hydrochloric acid upon the following reaction:

CaCO3 + 2 HCl = CaCl2 + H2O + CO2

Limestone is used as source of calcium carbonate.
The purification of the product is mainly accomplished by adding Ca(OH)2, in order to remove Magnesium.
The high purity of the produced carbon dioxide makes it suitable for applications within the food and pharmaceutical industries.

The 36% solution obtained with the above reaction is filtered and then stored or sent to:

  • a fluid bed dryer granulator, obtaining a 94-97% product

or concentrated up to 72% and sent to:

  • a flaking unit, obtaining a 75-78% product

For the production of 94-97% granules, Consito, in partnership with a well known European manufacturer, developed a special fluid bed dryer with internal heat recovery, which can be fed directly with the 36% solution coming from the neutralisation, avoiding the concentration step.

Operating data

Typical final product quality:

Referred to 94% granules

Purity Minimum 94% CaCl2
Appearance White free-flowing pallets, no lumps
Specific Gravity 2.15
Moisture < 0.5 % w/w
Water Insoluble’s < 1% w/w. These should be soluble in 15% HCl
Turbidity < 50 NTU for 36% by weight solution of CaCl2 in distilled water
Suspended Solids < 0.2% w/w
Sulphate as CaSO4 < 0.05% w/w
Magnesium < 0.4% w/w
Iron Content < 0.1% w/w
Water Solubility > 99% w/w
Pallets Size 1mm – 4mm diameter
Alkali Chloride < 6%
Calcium hydroxide < 0.2%
Typical main raw material and utility consumptions:

Referred to 1 metric ton of finished product at 94%:

Feedstock & utilities
HCl 100% basis kg 650
Limestone (CaCO3) kg 950
CaCl2 kg 1,000
CO2 kg 390
Filter cake kg 55
Electric power kWh 45
Process water kg 80
Fuel gas kg 130
Compressed air Nm3 20

Calcium chloride applications

Calcium chloride is a versatile chemical, so it is utilized in many industries and application areas:

  • Agricultural nutrients
  • Animal feed
  • De-icing
  • Distilleries
  • Dust binding
  • Chemical heating
  • Concrete acceleration
  • Dehumidification
  • Food Processing
  • Gas and solvent drying
  • Mining industry
  • Oil & gas drilling
  • Tire weighting