Fertilizer grade

It is customary to refer to a given fertilizer product by a series of numbers separated by dadies. This set of numbers is called the grade of the fertilizer product. Each of the numbers indicates the amount of a nutrient that the manufecturer guarantees is contained in the fertilizer product. This number includes only the amount of nutrient found by prescribed analytical procedures, thereby excluding any nutrient present in a form that is deemed to be unavailable for plant nutrition. The content of each nutrirat is always expressed as a percentage by 

Expressed on an elemental basis, the fertilizer grade of this product would be 12-2.6-18.3-1.2Mg T Ie 1.2). 

In this manual, the oxide form will be used unless otherwise spedfied. 

Many sparingly soluble materials have been found to be available to plants and, in some cases, even more effective than readily water-soluble materials. However, some materials are so Insoluble as to be virtually worthless as fertilizers. Therefore, most countries specify some degree of solubility of the nutrient content in water or other reagents or alternatively require identification and approval of the source of the material. 

For example, natural organic materials may be acceptable on the basis of total N, P2O5, and K2O content, provided the source of the material is identified and approved. Synthetic organic materials, if sparingly soluble, may require special methods of analysis, particularly if intended for controUed-relcase fertilizers. Likewise, special tests may be required for coated controlled-release fertilizers. 

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Table 8. Specifications of Fertilizer-Grade Granular Diammonium Phosphate ...

Potassium Chloride. The principal ore encountered in the U.S. and Canadian mines is sylvinite [12174-64-0] a mechanical mixture of KCl and NaCl. Three beneficiation methods used for producing fertilizer grades of KCl ate thermal dissolution, heavy media separation, and flotation (qv). The choice of method depends on factors such as grade and type of ore, local energy sources, amount of clay present, and local fuel and water availabiUty and costs. 

Most limestone quarries use either 100% ammonium nitrate [6484-52-2] (fertilizer grade) and fuel oil (ANFO), or a combination of ANFO and ammonium or gelatin dynamite, for blasting (see Explosives and propellants, explosives). After blasting, oversized boulders usually are reduced to manageable sizes by drop ball cranes. 

Sulfur-coated urea is produced ki North America by a number of suppHers including ICl Canada (Courtright, Ontario), Lesco, Inc. (Martins Ferry, Ohio), PurseU Industries (Sylacauga, Alabama), and The O.M. Scott Sons Co. (Marysville, Ohio). All produce a number of fertilizer grades and particle sizes. Sulfur-coated ureas and compound (N—P—K) fertilizers also are produced by Mitsui Toatsu (Japan). 

Observable Characteristics - Physical State (as normally shipped) Solid Color Colorless (pure) to gray or brown (fertilizer grades) Odor None. 

A "fertilizer-grade" product is obtained by treating phosphate rock with sulfuric acid. 

Explosive-related chemical Explosive remnants of war Electrostatic discharge Explosives trace detection Explosive vapor detection (U.S.) Federal Aviation Administration Field asymmetric ion mobility spectrometry Fertilizer-Grade AN (ammonium nitrate)... 

Fertilizer grade product is obtained by pulverized phosphate rock (tricalcium phosphate) in phosphoric or sulfuric acid and evaporating the solution. 

Refs 1) P.F. Macy et al, "Investigation of Sensitivity of Fertilizer Grade Ammonium Nitrate to Explosion , PicArsn SFALTech-Rept 1658(1947) 2) E. Harvey et al, JACS... 

The Capital Chemist, March 1966, p 71 22) Anon, "Fertilizer-Grade Ammonium Nitrate (Gave no detonation when burned alone but detonated when mixed with com-... 

The expl may also be agitated at room or elevated temp with hydroxides of alkali or alka-line earth metals (pref calcium hydroxide) with or without application of pressure (Ref 4) [See also Ammonium Nitrate, Fertilizer Grade (FGAN) in Vol 1 of Encycl, p A364]... 

See AMMONIUM NITRATE, FERTILIZER GRADE in Vol 1, pp A364-L to A367-L and also pp A359 R to A362-L... 

Fires and Explosions of Ammonium Nitrate, Including FGAN (Fertilizer Grade Ammonium Nitrate). See Vol 1 of EnCycl, pp A357-L... 

It is advisable to use ammonium nitrate with as little as possible of the inert material usually added to ammonium nitrate to prevent its caking. According to the same source, the quantity of inert material should not exceed 0.4% of NH4N03 (fertilizer grade ammonium nitrate usually contains 2-5% added matter). 

CA 56, 5012(1962) [Mixts of fertilizer-grade AN and a liquid hydrocarbon (such as Diesel oil), are sensitized to initiation by an ordinary blasting cap by adding a saturated sol n of AN at >150°F, followed by drying]... 

CA 57, 2490(1962) [An expl prepd from clay-coated fertilizer-grade AN by heating and agitating it. with a combustible material which... 

Permissible expl prepd from fertilizer-grade AN prills (with/or without NaNOg) and small amts of fine Al, Fe203, fuel (sucb as activated charcoal), sulfur, ground glass lime dust)... 

Nitrome thane-Nitropropane-Thickener expl compositions having high rates of deton, but being non-cap-sensitive, are described. They were useful in marine seismic exploration work. For their prepn 800 lbs fertilizer-grade AN prills (previously ground to pass 10-mesh screen of which 22% passed 200-mesh) were intimately mixed with 104 lb MeNC>27 86 lb PrN02 ... 

Urider Preparation of Fertilizer Grade Ammonium Nitrate. This process has not been used for making ammonium nitrate fertilizer since 1948, as mentioned above... 

Anon, US Coast Guard, "Rept of Interagency Comm on the Hazards of AN Fertilizer Grade, in Land Transportation and in Storage Under Various Conditions , ... 

References on Ammonium Nitrate, Fertilizer Grade (FGAN) I)G.Rosendahl, ChemZtr... 

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