Phosphating applications

Comor, J.J., Tolic, A.S., Kopecni, M.M., Petkovic, D.J. 1999. Modeling of the simultaneous extraction of nitric acid and uranyl nitrate with tri-n-butyl phosphate. Application to extraction operation. Sep. Sci. Technol. 34 (1) 115-122. 

The content and type of iron oxide affects soil chemistry. Several workers (e.g., Scheinost and Schwertmann 1995) have shown that phosphate adsorption maxima increase from red (hematitic) to yellow (goethite-rich) soils. Consequently, because yellow soils in some regions are closely correlated to soil P sorption, soil color has been used to predict the likely need for phosphate applications. 

Giraud, S., Bourbigot, S., Rochery, M., Vroman, I., Tighzert, L., and Delobel, R. 2002. Microencapsulation of phosphate—Application to flame retarded cotton. Polym. Deg. Stab. 77 285-297. 

In general, zinc deficiency can be overcome by applying zinc salts to the soil, though the effect of a zinc-containing fertilizer on the mineral nutrition of rice depends on the planfs tolerance towards zinc deficiency. Organic compounds such as zinc chelates are more effective than inorganic salts with equivalent amounts of zinc (Vitosh etal. 1994). Phosphate application has also been suggested as a means of... 

Phosphate Recovery by Reactive Crystallization of Magnesium Ammonium Phosphate Application to Wastewater... 

Phosphate applications in relation to detergency are the stabilisation of suspensions, pH control, corrosion prevention and water softening (either by precipitation or by sequestration) (Section 12.6) (Chapter 5.3). Patent literature on these topics dates back 70-80 years, and that on the use of polyphosphates as surfactants and builders for traditional soaps covers about the same period. 

The main advantage of melamine phosphate (Melapur MP) is its low water solubility compared with ammonium-based phosphates. Applications range from thermoplastics to thermosetting resins. 

An off-shoot of this is the bacterial treatment of agricultural ground. Russian work has indicated that the application of sulfur, plus bacteria, can make phosphorus available for use by the growing pleuit in situ, phosphorus present in the soil that otherwise would be unavailable. This, then could result in a lowering of fertilizer phosphate application. To our knowledge, nothing has been done along these lines in the U.S. 

Quintana JC, Idrissi L, Palleschi G, Albertano P, Amine A, El Rhazi M, Moscone D (2004) Investigation of amperometric detection of phosphate application in seawater and cyanobacterial biofilm samples. Talanta 63 567-574... 

Table XI-1 (from Ref. 166) lists the potential-determining ion and its concentration giving zero charge on the mineral. There is a large family of minerals for which hydrogen (or hydroxide) ion is potential determining—oxides, silicates, phosphates, carbonates, and so on. For these, adsorption of surfactant ions is highly pH-dependent. An example is shown in Fig. XI-14. This type of behavior has important applications in flotation and is discussed further in Section XIII-4.

Martens J A and Jacobs P A 1999 Phosphate-based zeolites and molecular sieves Catalysis and Zeolites, Fundamentals and Applications ed J Weitkamp and L Puppe (Berlin Springer) pp 53-80... 

In general, the first step in virtual screening is the filtering by the application of Lipinski s Rule of Five [20]. Lipinski s work was based on the results of profiling the calculated physical property data in a set of 2245 compounds chosen from the World Drug Index. Polymers, peptides, quaternary ammonium, and phosphates were removed from this data set. Statistical analysis of this data set showed that approximately 90% of the remaining compounds had ... 

The above is a general procedure for preparing trialkyl orthophosphates. Similar yields are obtained for trimethyl phosphate, b.p. 62°/5 mm. triethyl phosphate, b.p. 75-5°/5 mm. tri-n-propyl phosphate, b.p. 107-5°/5 mm. tri-Mo-propyl phosphate, b.p. 83-5°/5 mm. tri-wo-butyl phosphate, b.p. 117°/5-5 mm. and tri- -amyl phosphate, b.p. 167-5°/5 mm. The alkyl phosphates are excellent alkylating agents for primary aromatic amines (see Section IV,41) they can also be ua for alkylating phenols (compare Sections IV,104-105). Trimethyl phosphate also finds application as a methylating agent for aliphatie alcohols (compare Section 111,58). 

Direct Application Rock. Finely ground phosphate rock has had limited use as a direct-appHcation fertilizer for many years. There have been widely varying results. Direct appHcation of phosphate rock worldwide amounts to about 8% of total fertilizer phosphate used, primarily in the former Soviet Union, France, Brazil, Sri Lanka, Malaysia, and Indonesia. The agronomic effectiveness of an apatitic rock depends not only on the fineness of the grind but also strongly on the innate reactivity of the rock and the acidity of the sod performance is better on more acid sods. Probably more than half of the potentially productive tropical sods are acidic, some with pH as low as 3.5—4.5. Certain phosphate rocks may thus become increasingly important as fertilizer in those areas. The International Fertilizer Development Center at Muscle Shoals, Alabama is active in researching this field (30). 

Applications. The capabiHties of a gc/k/ms in separating and identifying components in complex mixtures is very high for a broad spectmm of analytical problems. One area where k information particularly complements ms data is in the differentiation of isomeric compounds. An example is in the analysis of tricresyl phosphates (TCPs) used as additives in a variety of products because of thek lubricating and antiwear characteristics (see Lubrication and lubricants). One important use of TCPs is in hydrauHc fluid where they tenaciously coat metal surfaces thereby reducing friction and wear. Tricresyl phosphate [1330-78-5] (7.2 21 exists in a variety of isomeric forms and the commercial product is a complex mixture of these isomers. 

For second-order NLO applications, the films need to be noncentrosymmetric. 4-Di(2-hydroxyethyl)amino-4 -a2oben2enephosphonate was used to form SAMs on 2irconium-treated phosphorylated surfaces. Further reaction with POCl and hydrolysis created a new phosphorylated surface that could be treated with 2irconium salt (341—343). The principal advantage of the phosphate systems is high thermal stabiUty, simple preparation, and the variety of substrates that can be used. The latter is especially important if transparent substrates are required. Thiolate monolayers are not transparent, and alkyltrichlorosilanes have a serious stabiUty disadvantage. 

Phosphate rock. In this application, the rotary Idln is used to nodulize the fines in the ore and prepare them for electric-furnace operation. Ore under 5 cm in size and containing 50 percent or more minus 100 mesh is calcined. Ore nodulizes at approximately 1475 to 1500 K. 

Shaft Furnaces The oldest and most important application of the shaft furnace is the blast furnace used for the production of pig iron. Another use is in the manufac ture of phosphorus from phosphate rock. Formerly hme was calcined exclusively in this type of furnace. Shaft furnaces are widely used also as gas producers. Chemicals are manufac tured in shaft furnaces from briquetted mixtures of the reacting components. 

Typical applications include primary devv atering of phosphate rock matrix and silica sand products following vv et screening. In ore dressing it is used rnainlv to protect large-diameter thickeners bv scalping out-l-65-mesh material,... 

Typical applications include careful sizing of silica-glass sand, washing phosphate rock, sizing of abrasives, smokeless powder, sodium ahi-rninate, etc,... 

Eleetrostatie-type separation is being tested as an alternath c to the presently used process oF Rotation oF pebble phosphates For eoarser-size Fractions, Advantages sought include reduced reagent costs, a lower water requirement, and Fewer tailings-disposal problems when a part oF the Rotation circuit is eliminated. The largest application oF triboeleetrie separation is in the salt industry where sodium and potassium salts are separated aFter preconditioning. 

The chemical reaction catalyzed by triosephosphate isomerase (TIM) was the first application of the QM-MM method in CHARMM to the smdy of enzyme catalysis [26]. The study calculated an energy pathway for the reaction in the enzyme and decomposed the energetics into specific contributions from each of the residues of the enzyme. TIM catalyzes the interconversion of dihydroxyacetone phosphate (DHAP) and D-glyceraldehyde 3-phosphate (GAP) as part of the glycolytic pathway. Extensive experimental studies have been performed on TIM, and it has been proposed that Glu-165 acts as a base for deprotonation of DHAP and that His-95 acts as an acid to protonate the carbonyl oxygen of DHAP, forming an enediolate (see Fig. 3) [58]. 

Although acid caseins are employed for a number of purposes, rennet caseins in which the protein remains associated with calcium and phosphate are preferred for plastics applications. Rennet is the dried extract of rennin, obtained from the inner lining of the fourth stomach of calves, and is a very powerful coagulant. As little as 0.2 parts per million are said to be sufficient to coagulate slightly acidic milk. Its coagulating power is destroyed at 100°C. 

---