Borate sodium

BP Borax JP Sodium borate PhEur Borax USPNF Sodium borate 

Borax decahydrate boric acid disodium salt E285 natrii tetraboras sodium biborate decahydrate sodium pyroborate decahydrate sodium tetraborate decahydrate. 

Sodium borate is used in pharmaceutical applications similarly to boric acid (see Boric Acid). It has been used externally as a mild astringent and as an emulsifying agent in creams. It has also been used in lozenges, mouthwashes, otic preparations (0.3% w/v), and ophthalmic solutions (0.03-1.0% w/v). Sodium borate has additionally been investigated in the prevention of crystal formation in freeze-dried solutions. Preparations of sodium borate in honey have historically been used as paints for the throat, tongue, and mouth, but such use is now inadvisable because of concerns about toxicity in such applications, see Section 14. Sodium borate is also used in cosmetics such as moisturizers, deodorants, and shampoos. 

Sodium borate occurs as white, hard crystals, granules, or crystalline powder. It is odorless and efflorescent. 

Melting point 75°C when rapidly heated. At 100°C it loses 5H2O at 150°C it loses 9H2O and at 320°C it becomes anhydrous. At about 880°C the substance melts into a glassy state borax beads.  

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Caffeine in tea and coffee is determined by CZE using nicotine as an internal standard. The buffer solution is 50 mM sodium borate adjusted to pH 8.5 with H3PO4. A UV detector set to 214 nm is used to record the electropherograms. 

Weber, P. L. Buck, D. R. Capillary Electrophoresis A Past and Simple Method for the Determination of the Amino Acid Composition of Proteins, /. Chem. Educ. 1994, 71, 609-612. This experiment describes a method for determining the amino acid composition of cyctochrome c and lysozyme. The proteins are hydrolyzed in acid, and an internal standard of a-aminoadipic acid is added. Derivatization with naphthalene-2,3-dicarboxaldehyde gives derivatives that absorb at 420 nm. Separation is by MEKC using a buffer solution of 50 mM SDS in 20 mM sodium borate. 

The toxicity of sodium peroxoborate hexahydrate in solution is equivalent to those of sodium borate and hydrogen peroxide. The LD q (mouse, oral) is 1060 mg/kg (2). Local use of high concentrations in the mouth can cause chemical bums and other problems (25). No TLV has been estabhshed. 

Modijications to the Recope Cycle. The recovery system is a principal capital cost in a kraft mill. Consequently, any recovery process that is less expensive to build can improve pulping economics. There have been numerous attempts to improve the kraft recovery process. Two examples are the direct alkaline recovery scheme (DARS) and the autocausticizing scheme using sodium borates (37). Both schemes eliminate the lime loop of the conventional kraft mill. As of 1996, neither is commercially used. 

Sodium is not found ia the free state ia nature because of its high chemical reactivity. It occurs naturally as a component of many complex minerals and of such simple ones as sodium chloride, sodium carbonate, sodium sulfate, sodium borate, and sodium nitrate. Soluble sodium salts are found ia seawater, mineral spriags, and salt lakes. Principal U.S. commercial deposits of sodium salts are the Great Salt Lake Seades Lake and the rock salt beds of the Gulf Coast, Virginia, New York, and Michigan (see Chemicals frombrine). Sodium-23 is the only naturally occurring isotope. The six artificial radioisotopes (qv) are Hsted ia Table 1 (see Sodium compounds). 

Manufacture. The majority of boric acid is produced by the reaction of inorganic borates with sulfuric acid in an aqueous medium. Sodium borates are the principal raw material in the United States. European manufacturers have generally used partially refined calcium borates, mainly colemanite from Turkey. Turkey uses both colemanite and tincal to make boric acid. 

A unique Hquid—Hquid extraction process for manufacturing boric acid from sodium borate brines has been operated at Seades Lake, Trona, California, by the North American Chemical Co. since 1962. Both potassium sulfate and sodium sulfate are produced as coproducts in this process. 

Inorganic boron compounds are generaHy good fire retardants (59). Bode acid, alone or in mixtures with sodium borates, is particularly effective in reducing the flammabHity of ceUulosic matetials. AppHcations include treatment of wood products, ceUulose insulation, and cotton batting used in mattresses (see Flame retardants). 

Sodium borate solutions near the Na20 B202 ratio of maximum solubihty can be spray-dried to form an amorphous product with the approximate composition Na20 4B202 4H20 commonly referred to as sodium octaborate (64). This material dissolves rapidly in water without any decrease in temperature to form supersaturated solutions. Such solutions have found apphcation in treating ceUulosic materials to impart fire-retardant and decay-resistant properties (see Cellulose). 

Borax Decahydrate and Pentahydrate. Borax decahydrate and pentahydrate are produced from sodium borate ores, dry lake brines, colemanite, or magnesium borate ores. 

Production from sodium borate ores takes place in the United States, Turkey, and Argentina. AH U.S. production based on sodium borate ores is from the United States Borax Chemical Corp. in Boron, California. Turkish mining of tincal takes place at Kirka. This operation is under the control of the Turkish government and its representative, Etibank. Argentine production is carried out at Tincalayu, primarily by Boroquimica Samicaf. 

The source of Argentine production is an open-pit tincal mine at 4000 m above sea level. A modem plant is located near the mine site. Total production of sodium borates is approximately 200,000 metric tons per year (101). 

Etibank is the sole producer of boron minerals and derivatives in Turkey, which is second in production only to the United States. The open-pit Kirka mine in the Eskisehir Province is the only source of Turkish sodium borate ore. A tincal concentrate is produced from ore that has been blasted and carried in tmcks to the concentration plant. The ore is screened and cmshed to reduce it to —100 mm and then hammer milled to —25 mm. The stockpiled material is further milled and screened to 6 mm. A fraction of +1 mm (+18 mesh, U.S. Standard) is washed and classified to remove fine clay. Clay is removed from the —1 mm faction bypassing it through cyclones and then through a classifier. This material is centrifuged and combined with the washed + 1 mm faction to produce a final product which is a —6 mm concentrate having 6—8 wt % moisture and 32% 2 3 1987 production was... 

The derivatives plant is designed to aimuaHy produce 160,000 t of borax pentahydrate, 17,000 t of borax decahydrate, and 60,000 t of anhydrous borax. A reported 50,000 t of borax pentahydrate was produced in 1987. A sodium borate refinery is fed from stockpiled tincal ore or product from the concentration plant. The feed is dissolved using steam to give a solution 18% in The solution is then passed through a series of filters and sent to a... 

Production of borax from the reaction of colemanite and sodium carbonate is carried out in Spain, Italy, and Poland. Turkish production from colemanite has been discontinued in favor of direct production from tincal ore. Sodium borates are produced in Russia from datoHte and in Kazakhstan from szaibelyite. 

Other Sodium Borates. SOLUBOR, TIM-BOR, or POLYBOR (63), proprietary products of United States Borax Chemical Corp., have the approximate composition of disodium octaborate tetrahydrate, Na20 4320 4H2O. This material is produced by spray-drying mixtures of borax and boric acid. 

Other Sodium Borates. Prices for disodium octaborate tetrahydrate (SOLUBOR, TIM-BOR, POLYBOR), sodium metaborate tetrahydrate, and sodium metaborate dihydrate in 1985 were 924/1, 880/t, and 1034/1, respectively. The corresponding prices in 1990 were 1056/t, 990/t (technical grade), and 1298/t (technical grade), respectively (33). 

Sodium borate (borax) [1330-43-4] M 201.2, m 741 , d 2.37. Most of the water of hydration was removed from the decahydrate by evacuation at 25° for three days, followed by heating to 100° and evacuation with a high-speed diffusion pump. The dried sample was then heated gradually to fusion (above 966°), allowed to cool gradually to 200°, then tranferred to a desiccator containing P2O5 [Grenier and Westrum J Am Chem Soc 78 6226 1956]. 

Sodium borate (decahydrate, hydrated borax) [1303-96-4] M 381.2, m 75 (loses 5H2O at 60 ), d 1.73. Crystd from water (3.3mL/g) keeping below 55° to avoid formation of the pentahydrate. Filtered at the pump, washed with water and equilibrated for several days in a desiccator containing an aqueous solution saturated with respect to sucrose and NaCl. Borax can be prepared more quickly (but its water content is somewhat variable) by washing the recrystd material at the pump with water, followed by 95% EtOH, then Et20, and air dried at room temperature for 12-18h on a clock glass. 

Fig. 2.12 Potential-time curves on mild steel in sodium borate/hydrochloric acid buffer solutions, pH 7-60, oxygen-saturated solution (after Ashworth )...

Tin when made anodic shows passive behaviour as surface films are built up but slow dissolution of tin may persist in some solutions and transpassive dissolution may occur in strongly alkaline solutions. Some details have been published for phosphoric acid with readily obtained passivity, and sulphuric acid " for which activity is more persistent, but most interest has been shown in the effects in alkaline solutions. For galvanostatic polarisation in sodium borate and in sodium carbonate solutions at 1 x 10" -50 X 10" A/cm, simultaneous dissolution of tin as stannite ions and formation of a layer of SnO occurs until a critical potential is reached, at which a different oxide or hydroxide (possibly SnOj) is formed and dissolution ceases. Finally oxygen is evolved from the passive metal. The nature of the surface films formed in KOH solutions up to 7 m and other alkaline solutions has also been examined. 

Mixtures of sodium borate and nitrite have been used to store plant. The solution may either be left in. If this is impracticable, for instance if the plant needs to be drained for maintenance purposes, then the solution may be drained from the plant after initial dosing so as to leave locations which are difficult to drain containing a residue of inhibitive solution . 

Acetone powder (1.5 g) was extracted 4 times with 0.1 M sodium borate buffer (pH 7.6) at 4°C, homogenizing each time with a glass grinder equipped with a Teflon pestle. The first extraction was carried out with 80 ml of the buffer, followed by 3 times with 70 ml each of the buffer. Each homogenate was centrifuged at 16,000 g for 5 min. All supernatants were combined. 

Sodium Borate Hydrogen Peroxidate, BNa02.H20 May react violently in close contact (grinding or heating) with oxidizable materials Kirk Othmer 11 (1966), 395... 

Benzoate can be used as an anodic inhibitor and is effective at preventing waterline attack. Phosphate is also sometimes included. Sodium borate (borax) is usually added to the formulation to provide an alkalinity reserve buffer. Typically, a copper inhibitor such as benzo-triazole (BTA) or tolyltriazole (TTA) also forms part of a formulation and is used to provide yellow metal (copper and brasses) protection. 

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