Ammonium phosphates monoammonium phosphate

Ammonium Phosphate. Ammonium phosphates have a long history of use as a fertilizer. They are not as easily leached from the soil as ammonium nitrate, but cannot be made in high nitrogen concentrations. There are three forms of ammonium phosphate monoammonium phosphate (MAP, NH4H2P04), diammonium phosphate (DAP, [NH4]2HP04), and triammonium phosphate (TAP, [NH4]3P04). Unfortunately, triammonium phosphate is unstable and loses ammonia easily. Ammonium phosphates are produced by reacting ammonia with phosphoric acid (Reaction 3.8). 

Ammonium Phosphates. Monoammonium Phosphate [7722-76-1], NH4H2PO4, and diammonium phosphate [7783-28-0], (NH4)2HP04 (or mixtures of the two), have long been used for low cost flame retarding and afterglow prevention of paper, textiles, disposable nonwoven cellulosic fabrics, and wood products (42-44). Ammonium phosphate finishes are resistant to dry-cleaning solvents but not to water. 

Ammonium phosphates— Ammonium phosphates are produced mainly as either monoammonium phosphate or diammonium phosphate by reacting phosphoric acid with anhydrous ammonia. In many plants, 93%-98% sulfuric acid is used to control the composition of the final product. After the reactor and the granulator, the moist ammonium phosphate granules are transferred to a rotary dryer. 

See Ammonium phenolsulfonate Monoammonium phosphate. See Ammonium phosphate. 

The routes by which mineral phosphates are processed into finished fertilizers are outlined in Eigure 7. World and U.S. trends in the types of products produced are shown in Eigures 8 and 9, respectively. Most notable in both instances is the large, steady increase in the importance of monoammonium and diammonium phosphates as finished phosphate fertilizers at the expense of ordinary superphosphate, and to some extent at the expense of triple superphosphate. In the United States, about 65% of the total phosphate appHed is now in the form of granular ammonium phosphates, and additional amounts of ammonium phosphates are appHed as integral parts of granulated mixtures and fluid fertilizers. 

Phosphoric acid is a relatively strong acid and can cause extensive damage to polysaccharides. Ammonium phosphate salts are good fire retardants (1,7,13,18,22), are inexpensive, and should not cause acid-catalyzed hydrolysis or dehydration. However, if ammonium phosphate-treated wood is exposed to heat, ammonia will be given off and phosphoric acid will be left (7,39-43). The critical temperature at which monoammonium phosDhate thermally disassociates has been reported to be 166° (39), 170° (47), or 190°C (40). 

The ammonium phosphates took over the lead in 1967. Diammonium phosphate (DAP) is made from wet process phosphoric acid of about 40% P2O5 content and ammonia. The usual finishing NH3 H3P04 mole ratio is 1.85-1.94 1. Monoammonium phosphate (MAP) is made with a final NH3iH3P04 ratio of 1 1. Current production percentages for phosphate fertilizers are DAP, 67% MAP, 26% and TSP, 7%. 

Crystalline polyammonium catena-polyphosphate, (NH4) H2P 03 + 1, has been prepared by heating urea and monoammonium orthophosphate under ammonia vapor for 16 hours,1 by ammoniation of superphosphoric acid,2 by thermal condensation of urea phosphate,3 and by heating various ammonium phosphates in a current of ammonia.4,5 The procedure given below, in which crude ammonium tetrametaphosphate is reorganized and condensed to a long-chain polymer in a stream of ammonia, is straightforward and permits the use of common laboratory equipment and supplies. 

FIG. 20-73 (a) Maximum extent of noninertial growth (/d)max a function of fractional saturation of the powder feed S t for drum granulation, and (b) maximum extent normalized for differences in Sto- Feed powders ammonium sulfate (O) monoammonium phosphate ( ), diammonium phosphate (A), limestone ( ). [Adetayo etd.. Powder Tech., 82.37 (1995). ] With kind permission from Elsevier Science SA, Lausanne, Switzerland. 

This study resulted in a series of reports on a comprehensive evaluation of fire-retardant treatments for wood (2-6). One hundred and thirty single chemicals or combinations of chemicals in the form of various salts were evaluated for flame-spread reduction, smoke, and corrosivity. Diammonium phosphate ranked first in reducing flame spread, followed by monoammonium phosphate, ammonium chloride, ammonium sulfate, borax, and zinc chloride. Zinc chloride, although excellent as a flame retardant, promoted smoke and glowing. Ammonium sulfate was the least expensive, but under certain environmental conditions it was corrosive to metals. None of the 130 compositions tested was considered ideal because of the adverse effects on some of the properties of wood. Several reviews of the subject are available and provide additional background material (J, 7-JO). 

Figure 5. Effect of fire-retardant chemicals on oxygen index (21). Key V, ammonium sulfate +, sodium tetraborate decahyarate O, aisodium oc-taborate tetranydrate , boric acid A, monoammonium phosphate A, ammonium polyphosphate (11-37-0) O, zinc chloride , sodium dichromate X, untreated.

Ammonium phosphate fertilizers are relatively impure (purity ca. 85%), due to their being prepared with nonpurified wet-process acid. Commercial monoammonium phosphate contains 11 to 13% N and 48 to 53% P2O5 (theoretically 12.2% N, 61.7% P2O5). Commercial diammonium phosphate contains 16 to 18% N and 46 to 48% P2O5 (theoretically 21.2% N, 53.7% P2O,). 

Non-granular (powdery) mono-ammonium phosphate is obtained in the Swift process by reacting liquid ammonia with phosphoric acid containing 50% P2O5 in an impeller-stirred reactor. The reaction products (finely divided monoammonium phosphate and steam, temperature ca. 126°C) are fed in at the top of a tower. The steam is driven out by a counter-current of air from below, the solid ammonium phosphate sinking to the bottom. The wet-process acid used in this process does not have to be deslimed beforehand. 

Three granular fertilizers were made triple superphosphate, monoammonium phosphate (11-47-0), and ammonium phosphate-sulfate (16-20-0). This technology, with various modifications, was later used in numerous fertilizer plants around the world and was one of the more important granulation processes for many years. 

Conversion of Phenols to Amines. Aniline and some diphenylamine are formed when phenol and NHs solution are heated under pressure in the presence of FeCh, Al(OH)s, or Fe(OH)j. When NH and phenol or ortho-or para-cresols are reacted in the vapor phase over an AljO catalyst, yields of up to 88 per cent of the corresponding amines are obtained. However, these amines are customarily obtained by reducing the parent nitro compound, except in cases where it is difficult to obtain the required nitro isomer. For example, it is considered that the amination of symr xylenol is the best method of preparing sym-xylidine (l-amino-3,5-di-methylbenzene). When sym-xylenol is heated under pressure to 320 C with ammonium chloride, about equal amounts of sj/m-xylidine and sym-dixylylamine (5-imino-bis-l,3-dimethylbenzene) are formed. The ortho-and para-nitrophenols and nitrocresols can be aminat more readily. 2-Nitro-p-cresol [OH(l), N02(2), CHj(4)] and o-nitrophenol have been aminated in aqueous ammonia containing ammonium salts of weak acids to inhibit decomposition. Phosphoric, boric, carbonic, and formic acids were used. In one case it is claimed that 55-65 per cent yields of 2-nitro-p-toluidine (MNPT of commerce) were obtained when 2-nitro-p-cresol, 28 per cent aqueous NHj, and monoammonium phosphate, 1 11.5 0.2 molar ratio, were heated under pressure for 10 hr at 140-150°C and then 5 hr at about 160 C. Earlier workers, employing somewhat similar conditions, claimed excellent yields of MNPT when 1 mole of ammonium formate was used per mole of 2-nitro-p-cresol. ... 

Diammonium phosphate, exploited In Germany, is another ammonium phosphate containing twice the ammonia of the monoammonium phosphate and is produced by treating mono ammonium phosphate liquor with additional ammonia. This material contains 23 per cent of ammonia and 47 per cent of phosphoric acid. 

M S04 Mn2(S04>3 24H2O manganese(II) carbonate hydroxyphenylacetic acid manganese hydroxide monoammonium phosphate potassium tm(II) sulphate ammonium sulphate yellow lead monoxide ammonium hydrogen fluoride potassium iron(III) sulphate mercury(n) isocyanate hexamethylbenzene tetramethyldiamino-benzophenone... 

Aibrite MALP. See Aluminum orthophosphate Aibrite Monoammonium Phosphate Food Grade. See Ammonium phosphate Aibrite Monosodium Phosphate] Aibrite MSP Food Grade. See Sodium phosphate Aibrite N-Octyi Acid Phosphate. See 2-Ethylhexyl phosphate Aibrite Octyiphenyi Acid Phoshate. See Octyl phenyl acid phosphate Aibrite PA. See Phosphorous acid Aibrite PCk. See Phosphorus trichloride Aibrite Phenyi Acid Phosphate. See Phenyl acid phosphate... 

MAP Monoammonium phosphate Primary ammonium phosphate Empihcai H6NO4P Formuia NH4H2PO4... 

Although ammonium phosphate had long been known to be an effective fertilizer and small quantities had been produced in several countries from time to time, it did not become a popular fertilizer until the 1960s. Ammonium phosphates (diammonium phosphate and monoammonium phosphate) are now the leading form of phosphate fertilizer in the world. 

Ammonium phosphates, particularly DAP, are the most popular phosphate fertilizers worldwide because of their high analysis and good physical properties. The compositions of the pure salts - monoammonium phosphate (MAP) and DAP - are given in Table 12.4. 

Flame retardant (1947) n. A material that reduces the tendency of plastics to burn. Flame retardants are usually incorporated as additives during compounding, but sometimes applied to surfaces of finished articles. Some plasticizers, particularly the phosphate esters and chlorinated paraffins, also serve as flame retardants. Inorganic flame retardants include antimony trioxide, hydrated alumina, monoammonium phosphate, dicyandiamide, zinc borate, boric acid, and ammonium sulfamate. Another... 

Alpha-Methylstyrene Alpha-Methylstyrene Monoammonium Ammonium Phosphate... 

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