Phosphate trisodium

Excellent results are obtained with warm 15 per cent, trisodium phosphate solution to which a little abrasive powder, such as pumice, has been added. This reagent is not suitable for the removal of tars. 

Phosphorus is also important in the production of steels, phosphor bronze, and many other products. Trisodium phosphate is important as a cleaning agent, as a water softener, and for preventing boiler scale and corrosion of pipes and boiler tubes. 

Mona.Zlte, The commercial digestion process for m on a site uses caustic soda. The phosphate content of the ore is recovered as marketable trisodium phosphate and the rare earths as RE hydroxide (10). The usual industrial practice is to attack finely ground m on a site using a 50% sodium hydroxide solution at 150°C or a 70% sodium hydroxide solution at 180°C. The resultant mixed rare-earth and thorium hydroxide cake is dissolved in hydrochloric or nitric acid, then processed to remove thorium and other nonrare-earth elements, and processed to recover the individual rare earths (see... 

The rate of stripping or the stripabiUty on cataly2ed urethane and epoxy resin finishes can be increased by adding formic acid, acetic acid, and phenol. Sodium hydroxide, potassium hydroxide, and trisodium phosphate [10101-89-0] may be added to the formula to increase the stripabiUty on enamel and latex paints. Other activators include oleic acid [112-80-17, trichloroacetic acid [76-85-9], ammonia, triethanolamine [102-71-6], and monoethyl amine. Methylene chloride-type removers are unique in their abiUty to accept cosolvents and activators that allow the solution to be neutral, alkaline, or acidic. This abihty gready expands the number of coatings that can be removed with methylene chloride removers. 

Both mono- and disodium phosphates are prepared commercially by neutralization of phosphoric acid using sodium carbonate or hydroxide. Crystals of a specific hydrate can then be obtained by evaporation of the resultant solution within the temperature range over which the hydrate is stable. For the preparation of trisodium phosphate, sodium hydroxide must be used to reach the high end pH because CO2 cannot be stripped readily from the solution above a pH of near 8. 

The trisodium phosphate system is the most complex and the commercial product is generally of variable composition and often contains excess sodium hydroxide. It has long been recognized that the usual formula, Na PO does not accurately represent the constitution of this salt. A better... 

Fig. 7. Solubihty of sodium orthophosphates as a function of temperature (17,18). MSP, DSP, and TSP are mono-, di-, and trisodium phosphates,...

Trisodium phosphate is strongly alkaline many of its appHcations depend on this property. For example, many heavy-duty cleaning compositions contain trisodium phosphate as a primary alkalinity source. The crystalline dodecahydrate itself is marketed as a cleaning compound and paint remover. Traditionally, trisodium phosphate has been used in water softening to remove polyvalent metal ions by precipitation as insoluble phosphates. Because the hypochlorite complex of trisodium phosphate provides solutions that are strongly alkaline and contain active chlorine, it is used in disinfectant cleaners, scouring powders, and automatic dishwashing formulations. 

Boiler feed-water systems that use dernineralized or evaporated makeup or pure condensate may be protected from caustic attack through coordinated phosphate and pH control. Phosphate buffers the boiler water, reducing the chance of large pH changes due to the development of high caustic or acid concentrations. Excess caustic combines with disodium phosphate and forms trisodium phosphate. Sufficient disodium phosphate must be available to combine with all of the free caustic in order to form trisodium phosphate. 

Conversely, addition of trisodium phosphate adds caustic, increasing boiler water pH ... 

Chlorinated Trisodium Phosphate. Chlorinated trisodium phosphate [11084-85-8] is a crystalline complex of hydrated trisodium orthophosphate and sodium hypochlorite that releases hypochlorite when mixed with water. Its formula is (Na PO 11H20)4 NaOCl. Commercial... 

The use of chlorinated trisodium phosphate is declining. It has been largely replaced by chlorinated isocyanurates in powdered abrasive cleansers and automatic dishwash detergents to reduce cost, improve performance, or comply with restrictions on the use of phosphates. Some chlorinated trisodium phosphate is stiU used in commercial laundries and in disinfectant cleaners. 

Sodium Hypochlorite—Trisodium Phosphate Complex. Commercial crystalline trisodium phosphate (TSP) is a complex of the type (Na PO -xH20) NaY where n = 4 to 7, a = 11 or 12, and Y is a monovalent anion (see Phosphoric acids and phosphates). Chlorinated trisodium... 

Manufacture. Chlorinated TSP is made batchwise by addition of a 15% NaOCl solution containing some NaOH to a hot (75—80°C) concentrated Hquor consisting of di- and trisodium phosphates, in a mole ratio of about 1 10, in a suitable reactor, eg, a pan mixer (222). The mixture is allowed to cool slowly under constant agitation until crystallization occurs (62°C). When crystallization is complete, cooling is continued to about 45°C and the slightly moist crystals are air dried. Overdrying can result in decreased stabiHty. 

Economic Aspects. Sodium hypochlorite—trisodium phosphate complex was commercialized in 1930. Chlorinated TSP is manufactured by Stauffer (a subsidiary of Rhc ne-Poulenc, Inc.). The consumption, steadily decreasing since 1980, dropped sharply in 1985 because of reduced use in dishwasher detergents. The estimated demand in 1987 was 37,360 t (220). In 1988 it sold for 0.32/lb ( 0.70/kg) for tmddoad quantities of 660 kg (300-lb) dmms. 

Trisodium phosphate [7601-54-9] trisodium orthophosphate, Na PO, is an important constituent of hard-surface cleaners including those for ceramic, metal, or painted surfaces. It may be used with soaps, surfactants, or other alkaHes. It precipitates many heavy-metal ions but does not sequester to form soluble chelates. It is thus a precipitant builder and additionally an alkaH. 

Electrolyte is added to the recipe to help control particle size of the latex produced. Materials like sodium carbonate or trisodium phosphate are commonly used. 

Chemical Designations - Synonyms Sodium phosphate is generic term and includes the following (1) monosodium phosphate (MSP sodium phospWe, monobasic), (2) disodium phosphate (DSP sodium phosphate dibasic), (3) trisodium phosphate (TSP sodium phosphate, tribasic), (4) sodium acid pyrophosphate (ASPP SAPP disodium pyrophosphate (TSPP), (6) sodium metaphosphate (insoluble sodium metaphosphate), (7) sodium trimetaphosphate, and (9) sodium tripolyphosphate (STPP TPP) Chemical Formula (1) NaHjPO (2) Na HPO (3) NajPO (4) Na H P O, (5) Na P O, (6) (NaPOj) (7) (NaP03)3 (8) (NaP03) NaO (9) Na,P30,o. 

Trimolybdansaure, /. trimolybdic acid, trimorph, a. triniorphous, trimorphic. Trimorphie, /. trimorphism. Trinatriumphosphat, n. trisodium phosphate, trinkbar, a. drinkable, potable. 

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