Ammonium phosphates capacity

World ammonia capacity increased by nearly 14% from 1984 to 1996 while capacity for urea, the primary downstream nitrogen product, increased by 45%. The increases were due primarily to 1) a desire by some major importing countries to become more self-sufficient and 2) the construction of export-oriented capacity in the Middle East and in the former Soviet Union (prior to its breakup). Ammonium phosphate capacity increased by 9% between 1984 and 1996. Ammonium nitrate capacity declined by 2% from 1984 to 1996 while ammonium sulfate capacity declined by 8%35. 

In the future, developing nations are expected to continue to account for most of the increases in ammonia and urea capacity. Ammonia capacity is expected to increase by about 20 million tonnes and urea capacity by about 12 million tonnes of nitrogen between 1996 and 2002. The availability of relatively low-cost feedstock (usually natural gas) will be a major determinant as to where this new capacity is installed. Ammonium nitrate and ammonium phosphate capacity are also expected to rise35. The following tables summarize anticipated world capacity for nitrogen products by year (Table 3.1) and by major regions or countries (Table 3.2)148. 

In 4Q02 ammonium phosphate capacity in the United States was 9,705,000 tons per year of DAP and MAP. Approximately 70% of the product is DAP. Demand is summarized in the following table239 ... 

Figure 3.14. Ammonium Phosphate Capacity in the United States, Number of Producing Companies, 1975-95.

About 264,000 metric tons of elemental capacity is available in North America, plus another 79,000 t (P equivalent) of purified wet phosphoric acid (14). About 85% of the elemental P is burned to P2 5 hydrated to phosphoric acid. Part of the acid (ca 21%) is used direcdy, but the biggest part is converted to phosphate compounds. Sodium phosphates account for 47% calcium, potassium, and ammonium phosphates account for 17%. Pinal apphcations include home laundry and automatic dishwasher detergents, industrial and institutional cleaners, food and beverages, metal cleaning and treatment, potable water and wastewater treatment, antifree2e, and electronics. The purified wet acid serves the same markets. 

The peak capacity is not pertinent as the separation was developed by a solvent program. The expected efficiency of the column when operated at the optimum velocity would be about 5,500 theoretical plates. This is not a particularly high efficiency and so the separation depended heavily on the phases selected and the gradient employed. The separation was achieved by a complex mixture of ionic and dispersive interactions between the solutes and the stationary phase and ionic, polar and dispersive forces between the solutes and the mobile phase. The initial solvent was a 1% acetic acid and 1 mM tetrabutyl ammonium phosphate buffered to a pH of 2.8. Initially the tetrabutyl ammonium salt would be adsorbed strongly on the reverse phase and thus acted as an adsorbed ion exchanger. During the program, acetonitrile was added to the solvent and initially this increased the dispersive interactions between the solute and the mobile phase. 

The phosphate fertilizer industry is defined as eight separate processes phosphate rock grinding, wet process phosphoric acid, phosphoric acid concentration, phosphoric acid clarification, normal superphosphate, triple superphosphate, ammonium phosphate, and sulfuric acid. Practically all phosphate manufacturers combine the various effluents into a large recycle water system. It is only when the quantity of recycle water increases beyond the capacity to contain it that effluent treatment is necessary. 

Thorium phosphate-diphosphate Th4(P04)4P207 (TPD, Pcam) is an actinide host phase due to its very high chemical durability and radiation stability [165-167]. TPD is synthesized by drying of thorium nitrate and phosphorus acid or ammonium phosphate solution, cold pressing at 300-800 MPa, and sintering of pellets at 1100-1250 for 10-30 hours. Th" in the TPD structure may be replaced by other tetravalent actinides but its isomorphic capacity is reduced with decreasing cationic radii in the following sequence > Np" > Pu". ... 

The production of triple superpho.sphate with a P2O5-content greater than 40% and biologically more available phosphorus reached a peak in 1984 and has declined 30% since then. The worldwide capacity for triple superphosphate is considerably underutilized. Part of the spare capacity can be utilized for the manufacture of ammonium phosphate. The world production by region in 1990 is given in Table 2.5-5. 

The United States continues as the world s largest producer of phosphate fertilizers and expanded ammonium phosphate production capacity by 87% between 1975 and 1995 (Figure 3.14). However, maturity of the domestic market has forced U.S. phosphate producers to become more dependent on exports. In 1995, the United States exported more than 10.5 million tonnes of ammonium phosphate these exports accounted for about 63% of the U.S. production of ammonium phosphate. 

The production of fertilizers derived from phosphoric acid has increased significantly in the last 50 years because, among other things, these are high-analysis products, thanks to the removal of calcium as byproduct calcium sulfate in phosphoric acid production. Moreover, technical breakthroughs in the field of phosphoric acid and ammonium phosphate manufacture, plus economies of scale, have resulted in high capacity world size" plants, which produce a limited range of products at very competitive prices. 

TVA developed a process for producing granular ammonium polyphosphate, and in late 1973 the process was put into operation in a demonstration-scale plant with a capacity of 13-17 tph. The plant produced straight ammonium polyphosphate and urea-ammonium phosphate alternately. A flow diagram is shown in Figure 12.16. The process uses the heat of reaction of phosphoric acid (54% P2O5) with gaseous ammonia to evaporate water and dehydrate the ammonium phosphate,... 

AMP-1 4.0 Microcrystalline ammonium molybdo-phosphate with cation exchange capacity of 1.2 mequiv/g. Selectively adsorbs larger alkali metal ions from smaller alkali metal ions, particularly cesium. 

During the lifetime of a root, considerable depletion of the available mineral nutrients (MN) in the rhizosphere is to be expected. This, in turn, will affect the equilibrium between available and unavailable forms of MN. For example, dissolution of insoluble calcium or iron phosphates may occur, clay-fixed ammonium or potassium may be released, and nonlabile forms of P associated with clay and sesquioxide surfaces may enter soil solution (10). Any or all of these conversions to available forms will act to buffer the soil solution concentrations and reduce the intensity of the depletion curves around the root. However, because they occur relatively slowly (e.g., over hours, days, or weeks), they cannot be accounted for in the buffer capacity term and have to be included as separate source (dCldl) terms in Eq. (8). Such source terms are likely to be highly soil specific and difficult to measure (11). Many rhizosphere modelers have chosen to ignore them altogether, either by dealing with soils in which they are of limited importance or by growing plants for relatively short periods of time, where their contribution is small. Where such terms have been included, it is common to find first-order kinetic equations being used to describe the rate of interconversion (12). 

Biomass may also sorb As(III) from water. Teixeira and Ciminelli (2005) removed considerable As(III) with ground chicken feathers treated with ammonium thioglycolate. X-ray absorption near edge structure (XANES) spectra indicate that the adsorbed arsenic is still in the +3 valence state and that each atom is bound to three sulfur atoms associated with reduced cysteine amino acids (HC>2CCH(NH2)CH2SH) in the feathers. At pH 5 and biomass dosages of 2.0gL 1, the sorption capacity of the material was as high as 0.265 mmol As(III) g-1 biomass (19.9 mg As(III) g-1 biomass Table 7.2). The presence of 0.01 mol L-1 of phosphate had only minor effects on the sorption capacity, which was 0.260 mmol As(III) g 1 biomass (19.5 mg As(III) g-1 biomass) (Teixeira and Ciminelli, 2005, 898). 

The zirconium phosphate, a-ZrP, behaves as an ion exchanger where both hydrogen ions of the orthophosphate groups are exchangeable with sodium, potassium, and ammonium in two stages [109], It has an exchange capacity of 6.64 mequiv/g [111],... 

A buffer is frequently used in reversed-phase LC to reduce the piotolysis of ionogenic analytes, which in ionic form show little retention. Phosphate buffers are widely applied for that purpose, since they span a wide pH range and show good buffer capacity. The use of buffers is obhgatory in real world applications, e.g., quantitative bioanalysis, where many of the matrix components are ionogenic. LC-MS puts constraints to the type of buffers that can be used in practice. Phosphate buffers must be replaced by volatile alternatives, e.g., ammonium formate, acetate or carbonate. 

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