Calcium Nitrate
Calcium Nitrate, also called Norwegian saltpeter, is the inorganic
compound with the formula Ca(NO3)2. This colorless salt absorbs moisture
from the air and is commonly found as a tetrahydrate. It is mainly used as a
component in fertilizers but has other applications. Nitrocalcite is the name
for a mineral which is a hydrated calcium nitrate that forms as an
efflorescence where manure contacts concrete or limestone in a dry
environment as in stables or caverns. A variety of related salts are known
including calcium ammonium nitrate decahydrate and calcium potassium
nitrate decahydrate.
Identifiers
Specification:
SKU:D9003
CAS number: 13477-34-4
Items
Spec
Unit
Standard
HS Code: 2834299090
Properties
Purity
%≥
99
Molecular formula: Ca(NO3)2•4H2O
Appearance: Colorless Crystalline
CaO
%≥
23.5
N
%≥
11.7
pH Value
5-7
Molar mass: 236.15 (tetrahydrate)
Density: 1.896 g/cm3
Melting point: 42.7 °C
Boiling point: 132 °C (tetrahydrate)
Solubility in water
Insoluble Matter in
Water
%≤
0.01
tetrahydrate:
195 g/100 mL (0 °C)
129 g/100 mL (20 °C)
Heavy Metal(as Pb)
%≤
0.001
Sulphate
%≤
0.03
Iron (Fe)
%≤
0.005
Protection
363 g/100 mL (100 °C)
Solubility: dissolves in alcohol and
acetone
soluble in ammonia
almost insoluble in nitric acid
Operators should wear protective smock including respirator and rubber gloves, etc. Be
careful not to inhale the powder of calcium nitrate to protect respiration apparatus. In the
case of a fire, use water, soil or other fire extinguishing media but aqueous solution must
be prevented to flow towards inflammable materials.
Packing and
Storage
Plastic woven bag or Kraft paper bag inner with plastic bag in 25kg / 50kg / 500kg /
1000kg net
Store in a cool and dry house. The package must be sealed up and protected from
moisture. Avoid mixing with organic compound or sulphur during storage and
transportation. Prevent the material from rain and insolation. Load and unload carefully.
In the case of a fire, use water, soil or other fire extinguishing media but aqueous solution
must be prevented to flow towards inflammable materials.
Applications
Use in fertilizer
As of 1978, only 170,000 tons/year were produced for applications in fertilizers. The
fertilizer grade (15.5-0-0 + 19% Ca) is popular in the greenhouse and hydroponics trades;
it contains ammonium nitrate and water, as the "double salt" 5Ca(NO 3)2.NH4NO3.10H2O.
Formulations lacking ammonia are also known: Ca(NO3)2.4H2O (11.9-0-0 + 16.9%Ca). A
liquid formulation (9-0-0 + 11% Ca) is also offered. An anhydrous, air-stable derivative is
the urea complex Ca(NO3)2.4[OC(NH2)2], which has been sold as Cal-Urea.
Waste water treatment
Calcium nitrate is used in waste water pre-conditioning for odour emission prevention.
The waste water pre-conditioning is based on establishing an anoxic biology in the waste
water system. In the presence of nitrate, the metabolism for sulfates stops, thus
preventing formation of hydrogen sulphide. Additionally easy degradable organic matter
is consumed, which otherwise can cause anaerobic conditions downstream as well as
odour emissions itself. The concept is also applicable for surplus sludge treatment.
Concrete
Calcium nitrate is used in set accelerating concrete admixtures. This use with concrete
and mortar is based on two effects. The calcium ion accelerates formation of calcium
hydroxide and thus precipitation and setting. This effect is used also in cold weather
concreting agents as well as some combined plasticizers. The nitrate ion leads to
formation of iron hydroxide, whose protective layer reduces corrosion of the concrete
reinforcement.
Cooling baths
The dissolution of anhydrous calcium nitrate is highly endothermic (cooling). For this
reason, calcium nitrate is sometimes used for regenerateable cold packs.
Heat storage
Calcium nitrate together with Potassium and Sodium nitrate is used to absorb and store
energy in the Concentrated Solar Power plants. It can be used as a heat transfer fluid
instead of the thermal oil.
*Data from Wikipedia