Mixed fertilizers plants

Am POLLUTION FROM AGRO-INDUSTRY CHEMICALS Mixed Fertilizer Plants... 

Additional pollution control devices beyond the scrubbers, cyclones, and baghouses that are an integral part of the plant design and operations are generally not required for mixed fertilizer plants. 

Essentially all the ammonium sulfate fertilizer used in the United States is by-product material. By-product from the acid scmbbing of coke oven gas is one source. A larger source is as by-product ammonium sulfate solution from the production of caprolactam (qv) and acrylonitrile, (qv) which are synthetic fiber intermediates. A third but lesser source is from the ammoniation of spent sulfuric acid from other processes. In the recovery of by-product crystals from each of these sources, the crystallization usually is carried out in steam-heated sa turator—crystallizers. Characteristically, crystallizer product is of a particle size about 90% finer than 16 mesh (ca 1 mm dia), which is too small for satisfactory dry blending with granular fertilizer materials. Crystals of this size are suitable, however, as a feed material to mixed fertilizer granulation plants, and this is the main fertilizer outlet for by-product ammonium sulfate. 

Mixed fertilizers contain two or more of the elements nitrogen, phosphorus, and potassium (NPK), which are essential for good plant growth and high crop yields. This subsection briefly addresses the production of ammonium phosphates... 

Mixed solid fertilizers can be made by either direct granulation methods (40%) or bulk blending (40%). Bulk blending is made by mechanical mixing of the separate granular intermediate materials. It is usually done in small plants near the point of use. This technique is employed because the fertilizer can be tailor-made to fit the exact requirements of the user. Fluid or liquid fertilizers (clear, suspension, and slurry) account for 20% of all NPK mixed fertilizers. 

Mixed fertilizer A fertilizer that contains the plant nutrients nitrogen, phosphorus, and potassium. 

Producers can also source across a mix of plants, and maximize their production at plants offering the best economics at a given moment. Leading methanol producer Methanex exemplifies this approach, optimizing production across its global network. A number of players in the fertilizer industry are also developing this approach, including Koch Industries and Yara. 

Usually crystallizer product has a particle size that is about 90% finer than 16 mesh (about 1 mm in diameter), which is too small for satisfactory dry blending with granular fertilizer materials. Crystals of this size are suitable for use as a feed material to mixed fertilizer granulation plants, which is the main outlet for by-product ammonium sulfate244. 

H.B. Ries, A modern plant for the production of granulated mixed fertilizer, Aufbereit.-Tech., 16 (1) (1975) 17-26. 

Fig. 1 shows an agitated preneutralizer for mixing phosphoric acid and ammonia in a fertilizer plant. The slurry is very thick, with a specific gravity of 1.5 to 1.6. The agitator paddle is mounted on a 14-ft-long stainless-steel shaft suspended on the output shaft of a roof-mounted gear reducer. 

Nitrogen solutions (fertilizer) Plant foods, mixed made in plants producing nitrogenous fertilizer materials Urea... 

Binutrient and multinutrient fertilizers are often referred to as mixed fertilizers. The primary nutrient fertilizers have a rating convention which is designated by three weight percent numbers that identify the amount of N, P205, and K20 available for plant fertilization. 

Fig. 6.6-22 Mixed fertilizer compaction/granulation plant (courtesy Sudchemie AC, Munchen/Kehiheim, Germany)...

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