Calcium nitrate, additionally referred to as Norgessalpeter (Norwegian saltpeter), is an inorganic compound with the system Ca(NO3)2. This colourless salt absorbs moisture from the air and is usually discovered as a tetrahydrate. It’s primarily used as a part in fertilizers however has different functions. Nitrocalcite is the title for a mineral which is a hydrated calcium nitrate that types as an efflorescence the place manure contacts concrete or limestone in a dry atmosphere as in stables or caverns. Quite a lot of associated salts are recognized together with calcium ammonium nitrate decahydrate and calcium potassium nitrate decahydrate.[2]
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Manufacturing and reactivity[edit]
Norgessalpeter was synthesized at Notodden, Norway in 1905 by the Birkeland–Eyde course of. A lot of the world’s calcium nitrate is now made in Porsgrunn.
It’s produced by treating limestone with nitric acid, adopted by neutralization with ammonia:
It’s also an intermediate product of the Odda Course of:
It can be ready from an aqueous answer of ammonium nitrate, and calcium hydroxide:
Like associated alkaline earth steel nitrates, calcium nitrate decomposes upon heating (beginning at 500 °C) to launch nitrogen dioxide:[2]
Purposes[edit]
Use in agriculture[edit]
The fertilizer grade (15.5-0-0 + 19% Ca) is widespread within the greenhouse and hydroponics trades; it accommodates ammonium nitrate and water, because the “double salt”
5
Ca
(
NO
3
)
2
⋅
NH
4
NO
3
⋅
10
H
2
O
{displaystyle {ce {5Ca(NO3)2.NH4NO3.10H2O}}}
. That is referred to as calcium ammonium nitrate. Formulations missing ammonia are additionally recognized: Ca(NO3)2·4H2O (11.9-0-0 + 16.9 Ca) and the water-free 17-0-0 + 23.6 Ca. A liquid formulation (9-0-0 + 11 Ca) can be supplied. An anhydrous, air-stable by-product is the urea complicated Ca(NO3)2·4[OC(NH2)2], which has been offered as Cal-Urea.
Calcium nitrate can be used to regulate sure plant ailments. For instance, dilute calcium nitrate (and calcium chloride) sprays are used to regulate bitter pit and cork spot in apple timber.[3]
Waste water therapy[edit]
Calcium nitrate is utilized in waste water pre-conditioning for odour emission prevention. The waste water pre-conditioning relies on establishing an anoxic biology within the waste water system. Within the presence of nitrate, the metabolism for sulfates stops, thus stopping formation of hydrogen sulfide.[4] Moreover simple degradable natural matter is consumed, which in any other case could cause anaerobic situations downstream in addition to odour emissions itself. The idea can be relevant for surplus sludge therapy.[5]
Concrete[edit]
Calcium nitrate is utilized in set accelerating concrete admixtures. This use with concrete and mortar relies on two results. The calcium ion accelerates formation of calcium hydroxide and thus precipitation and setting. This impact is used additionally in chilly climate concreting brokers in addition to some mixed plasticizers.[6] The nitrate ion results in formation of iron hydroxide, whose protecting layer reduces corrosion of the concrete reinforcement.[7]
Latex coagulant[edit]
Calcium nitrate is a quite common coagulant in latex manufacturing, particularly in dipping processes. Dissolved calcium nitrate is part of the dipping tub answer. The nice and cozy former is dipped into the coagulation liquid and a skinny movie of the dipping liquid stays on the previous. When now dipping the previous into the latex the calcium nitrate will break up the stabilization of the latex answer and the latex will coagulate on the previous.[8][9]
Chilly packs[edit]
The dissolution of calcium nitrate tetrahydrate is very endothermic (cooling). Because of this, calcium nitrate tetrahydrate is typically used for regenerable chilly packs.[2]
Molten salts for warmth switch and storage[edit]
Calcium nitrate can be utilized as part of molten salt mixtures. Typical are binary mixtures of calcium nitrate and potassium nitrate or ternary mixtures together with additionally sodium nitrate.[10][11][12] These molten salts can be utilized to switch thermo oil in concentrated solar energy crops for the warmth switch, however principally these are utilized in warmth storage.
References[edit]
Navigation menu – “calcium nitrate formula”