Calcium borates

Some of the chemicals mentioned above and others, such as chlorinated mbber or paraffin, antimony trioxide, calcium carbonate, calcium borate, pentaerythrithol, alumina trihydrate, titanium dioxide, and urea—melamine—formaldehyde resin, may be used to formulate fire retardant coatings. Many of these coatings are formulated in such a way that the films intumesce (expand) when exposed to fire, thus insulating the wood surface from further thermal exposure. Fire retardant coatings are mostly used for existing constmction. 

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. 

Decahydrate, Pentahydrate, and Anhydrous Borax and Bulk Calcium Borates. The bulk borate products, borax decahydrate and pentahydrate, anhydrous borax, boric acid and oxide, and upgraded colemanite and ulexite, account in both toimage and monetary terms for over 99% of sales of the boron primary products industry (6). Economic considerations for all these products are highly interrelated, and most production and trade statistics do not distinguish the various products. 

Fluid loss additives such as solid particles and water-thickening polymers may be added to the drilling mud to reduce fluid loss from the well bore to the formation. Insoluble and partially soluble fluid loss additives include bentonite and other clays, starch from various sources, crushed walnut hulls, lignite treated with caustic or amines, resins of various types, gilsonite, benzoic acid flakes, and carefully sized particles of calcium borate, sodium borate, and mica. Soluble fluid loss additives include carboxymethyl cellulose (CMC), low molecular weight hydroxyethyl cellulose (HEC), carboxy-methYlhydroxyethyl cellulose (CMHEC), and sodium acrylate. A large number of water-soluble vinyl copolymers and terpolymers have been described as fluid loss additives for drilling and completion fluids in the patent literature. However, relatively few appear to be used in field operations. 

Antimony trioxide and chlorinated paraffinic derivatives are common materials used as fire retardants, as are intumescent zinc (or calcium) borate, aluminium hydroxide and magnesium hydroxide. These inorganic materials, used as bulk fillers, act to reduce the fire hazard. Halogenated materials release chlorine, which then combines with the antimony trioxide to form the trichloride, which is a flame suppressant. 

Calcium acetylide, 11 182-183 Calcium aluminum hydride, preparation and properties of, 8 327-329 Calcium borates, 25 218-219 stability ranges, 25 209-210 structures, 25 190-195, 197-199 in water, 25 218... 

Fig. 3. Schematic structures of the calcium borate minerals (a) frovolite, CaO B2O3 4 H2O, (b) pinnoite, MgO B2O3 3 H2O, and (c) vimsite, CaO B2O3 2 H2O (n = infinity)...

Daily dose of 100 mg calcium borate for 4 months Intravenous injection... 

Pentaborane Diborane Decaborane Sodium borate Boron trifluoride Calcium borate Boron tribromide Boron oxide Total dust Respirable fraction Sodium tetraborate Decahydrate... 

Calcium Borates. Found in nature as the minerals colemaniie. Ca BA0 i 5FLO. borocalcile. CaBjOr 4FLO, and pandermite CazB,.0, i 3FLO. See also Colemanite. 

Calcium borates are widespread in nature, and some are used for the commercial production of boric acid and its salts. As a result, extensive investigations have been made into their occurrence, decomposition, and dissolution in aqueous media. Some of the aqueous phase studies are given in Table VIII. 

With the selection of proper water content and reaction temperature, a new type of hard-core RMs sulfonates which contained an ultrafine calcium borate as an alkaline component was prepared. Since both reactants, calcium hydroxide and boric acid, are oil insoluble, water is necessary as a reaction medium in the presence of neutral calcium sulfonates. When water content was less than 5% of the sulfonates used, the rate of the reaction was too low and unreacted materials were present in significant quantity as coarse particles. With the water content... 

ZDDP + calcium sulfonate ZDDP + calcium borate-sulfonate... 

Additive status in tribofilm ZDDP => zinc polyphosphate PIBSI = iron oxide ZDDP > zinc polyphosphate Calcium borate-salicylate > calcium borate glass... 

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