superphosphate


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Related to superphosphate: bone meal, Triple superphosphate

superphosphate

or

superphosphate of lime,

Ca(H2PO4)2, is a compound produced by treating rock phosphate with sulfuric acid or phosphoric acid, or a mixture of the two. It is the principal carrier of phosphate, the form of phosphorus usable by plants, and is one of the world's most important fertilizers. Ordinary superphosphate contains about 20% available phosphate; double superphosphate (also called treble superphosphate) contains 40%–50% available phosphate.

Superphosphate

 

the most widely used mineral phosphorus fertilizer. The phosphorus in superphosphate is usually in the form of monocalcium phosphate and free phosphoric acid. The fertilizer contains gypsum and other admixtures, such as iron and aluminum phosphates, silica, and fluorine compounds. Superphosphate is obtained by the treatment of natural phosphates—apatite or phosphorite—or an apatite concentrate with sulfuric acid according to the reaction

Ca3(PO4)2 + 2H2SO4 = Ca(H2PO4)2 + 2CaSO4

Double superphosphate is derived by treating apatite or phosphorite with phosphoric acid.

Several types of superphosphate are produced industrially in the USSR. Ordinary superphosphate is a gray powder that is virtually noncaking and of average drillability; in fertilizer it provides 14–19 percent P2O5 that is available to plants. Granular superphosphate is derived from powdered superphosphate by adding moisture to it and rolling it into granules, usually 2–4 mm in diameter, in rotating drums. The granular type has a high drill-ability. Double superphosphate contains 45–48 percent available P2O5 and very little gypsum, and is usually made in granular form. Ammoniated superphosphate contains, in addition to 14–19.5 percent available P2O5, not less than 1.6 percent ammonia. Manganese superphosphate contains 1.5–2.5 percent manganese, boronated superphosphate contains 0.1–0.3 percent boron, and molybdic superphosphate contains 0.1 percent molybdenum.

Superphosphate is used in all soils as a basic presowing fertilizer; it may be applied at the time of sowing, in which case granular superphosphate is the best type, or for top dressing. It is especially effective in alkaline and neutral soils. In acidic soil the phosphoric acid of the fertilizer is converted into aluminum and iron phosphates, which are difficult for plants to assimilate. In this case, the effectiveness of the superphosphate is increased by mixing it with phosphorite flour, limestone, chalk, and humus before application to limed fields.

REFERENCES

Prianishnikov, D. N. Izbr. soch., vol. 1. Moscow, 1965.
Spravochnik po udobreniiam, 3rd ed. Moscow, 1964.
Superfosfat. Moscow, 1969. (Translated from English; edited by A. A. Sokolovskii.)

G. A. CHEREMISINOV

superphosphate

[¦sü·pər′fä‚sfāt]
(materials)
The most important phosphorus fertilizer, derived by action of sulfuric acid on phosphate rock (mostly tribasic calcium phosphate) to produce a mix of gypsum and monobasic calcium phosphate.

superphosphate

1. a mixture of the diacid calcium salt of orthophosphoric acid Ca(H2PO4)2 with calcium sulphate and small quantities of other phosphates: used as a fertilizer
2. a salt of phosphoric acid formed by incompletely replacing its acidic hydrogen atoms; acid phosphate; hydrogen phosphate
References in periodicals archive ?
On the basis of type, the global superphosphates market is segmented by regular superphosphates and triple superphosphates.
Summary: On the basis of type, the global superphosphates market is segmented by regular superphosphates and triple superphosphates.
The compositions of the utilized fertilizers were: reactive natural phosphate (29% [P.sub.2][O.sub.5] 32% Ca), single superphosphate (20% [P.sub.2][O.sub.5] 17% Ca, 11% S), urea (46%N), ammonium sulfate (21% N, 24%S) and potassium chloride (58% [K.sub.2]O).
(2007) described as one Kg of the single superphosphate fertilizer was dissolved in 16 liters of water and stirred vigorously.
The study was set in a randomized block design, with four replicates in a 2 x 6 factorial scheme, corresponding to two liming managements (with and without limestone application) and six forms of phosphate fertilization: Control (without phosphate fertilization) and combinations of [P.sub.2][O.sub.5] sources at dose of 90 kg [ha.sup.-1]: 100% natural phosphate (NP) (280 mg [dm.sup.-3] NP); 75% NP + 25% single superphosphate (SS) (210 mg [dm.sup.-3] NP + 62.5 mg [dm.sup.-3] SS); 50% NP + 50% SS (140 mg [dm.sup.-3] NP + 125 mg [dm.sup.-3] SS); 25% NP + 75% SS (70 mg [dm.sup.-3] NP + 187.5 mg [dm.sup.-3] SS; 100% SS (250 mg [dm.sup.-3] SS).
Under "damage to aircraft" the investigators said it was "destroyed", and had been carrying a full load of fuel and was beginning to dump a tonne of superphosphate before it crashed.
Ferghanaazot, Dekhkanabad Potash Fertilizer Plant, Kokand Superphosphate Plant, Ammophos-Maxam and Maxam-Chirchik companies conclude 2017 with low profitability, and Navoiazot with losses.
Homs, SANA - After a halt of more than two years, the superphosphate fertilizer plant in the General Fertilizer Company (GFC) in Homs resumed production with a capacity of 350 tons per day.
Single Superphosphate (SFS) is the oldest source of phosphorus for the manufacture of fertilizers.
It helps to neutralize acidity arising from nitrogenous compound (ammonium sulphate/nitrate and urea), neutralizes any free acid in the superphosphate components and contributes small amounts of Ca and Mg as plant nutrients.
In 2013-2014, DAP (diammonium phosphate) and SSP (single superphosphate) production in India stood at 3.6 million tons and 4.2 million tons, respectively.
2010), although strategic spelling of pastures and the application of superphosphate are critical for the persistence of exotic grasses (Cook et al.