Fertilizers potassium-based

International Plant Nutrition Institute. Available online. URL www. ipni.net/ppiweb/canadaw.nsf/ webindex/3044476L390951EB06256P 4000690213 open document navigator=home+page. Accessed on June 23, 2009. On this Web site, the International Plant Nutrition Institute describes the use of potassium-based fertilizers. 

Potassium is analyzed in chemicals that are used in the fertilizer industry and in finished fertilizers by flame photometric methods (44) or volumetric sodium tertraphenylboron methods (45) as approved by the AO AC. Gravimetric deterrnination of potassium as K2PtClg, known as the Lindo-Gladding method (46), and the wet-digestion deterrnination of potassium (47) have been declared surplus methods by the AO AC. Other methods used for control purposes and special analyses include atomic absorption spectrophotometry, inductively coupled plasma (icp) emission spectrophotometry, and a radiometric method based on measuring the radioactivity of the minute amount of the isotope present in all potassium compounds (48). 

Nutrient release patterns vary with the amount of coating appHed and the substrate used. Coating weights vary from 10 to 20%. Typically, commercial products are blends of different coating weights. Coated substrates kiclude, but are not limited to, urea, potassium sulfate, and ammonium nitrate-based N—P—K fertilizers. 

Chisso-Asahi Fertilizer Company, Ltd. This company utilizes thermoplastic resins, such as polyolefins, poly(vinyhdene chloride), and copolymers, as their coating materials. The coatings are dissolved in fast-drying chlorinated hydrocarbon solvents and are appHed to a variety of substrates including urea, diammonium phosphate [7783-28-0] potassium sulfate [7778-80-3], potassium chloride [7447-40-7], and ammonium nitrate/potassium sulfate-based N—P—K fertilizers. 

Well-rotted manures improve soil structure and water-holding capacity, and supply nitrogen, potassium, and other plant foods. Their nutrient content will vary with the proportion of manure and urine to straw or other bedding, and on whether they have been stored under cover or outdoors in the rain. However, they should be medium- to high-fertility soil improvers. Apply at a rate of one or two wheelbarrow loads (12-24 gal) per 50 sq ft (50-100 liters/5 sq m). When handling any animal-based product, keep cuts covered, wash your hands under running water before handling food, and be sure your tetanus vaccination is up to date. 

There are as many salts as there are acids and bases. Sodium cyanide, NaCN, is a deadly poison. Saltpeter, which is potassium nitrate, KN03, is useful as a fertilizer and in the formulation of gunpowder. Calcium chloride, CaCl2, is used ro deice roads, and sodium fluoride, NaF in toothpaste, prevents tooth decay. The acid-base reactions forming these salts are shown in Table 10.1. 

Several other processes for producing alumina based on ores other than bauxite have been announced. One process uses alunite, a hydrous sulfate of aluminum and potassium. It is claimed to be capable of producing 99% pure alumina from alunite containing only 10 to 15% alumina, compared with bauxite that assays 50% alumina. The alunite is crushed, dehydroxy-lated by heating to 750°C, ground, and treated with aqueous ammonia. Filtration removes the alumina hydrate, and potassium and aluminum sulfates are recovered from the filtrate (to be used as fertilizer constituents). The alumina hydrate is treated with sulfur dioxide gas, and the resulting aluminum sulfate is converted to alumina by heating in a kiln. 

Ammonia in Multinutrient Fertilizers. All the ammonia-based fertilizers discussed thus far contain only one of the three major plant nutrients, namely nitrogen. Referring again to Fig. 24.8, one may see that ammonia is the source of fertilizer nitrogen also, either directly or via nitrogen solids or solutions, in multinutrient fertilizers. These are fertilizers that contain two or three of the major plant nutrients—nitrogen, phosphorus, and potassium. Ammonium phosphates, both mono- and di-,... 

Figure 4 Schematic flowsheet of unit producing dinoptilolite-based potassium fertilizer from seawater. Fj and F2 clinoptilolite filters serve for potassium preconcentration and fertilizer production, respectively R1-R3 recuperators provide heating/cooling to solutions under treatment.

The fertilizer industry is based on replenishing the primary nutrients (i.e., nitrogen, phosphorus, and potassium). Commercially, fertilizers are produced in three different forms which are single nutrient, binutrient, and multinutrient. 

Compounds that contain hydroxide ions are often called hydroxides. All water-soluble hydroxides are strong bases. Examples include lithium hydroxide, LiOH, which is used in storage batteries and as a carbon dioxide absorbent in space vehicles, and potassium hydroxide, KOH, which is used to make some soaps, liquid fertilizers, and paint removers. 

There are three primary elements in fertilizers that require analytical determinations nitrogen (N) available phosphate (AP) for plant uptake expressed as P2O5 and water-soluble potassium expressed as K2O. Procedures are examined to determine values based on the best methods available for the primary elements, secondary elements, micronutrients in fertilizers, and other trace elements. Uniform methods can eliminate problems associated with fertilizer analyses, resulting in agreement between laboratories on a given sample. By following the exact procedures as outlined in an acceptable method, one can expect a reliable and reproducible chemical analysis. 

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