Fused borax

Hard, colorless crystals, or crystalline pieces, soluble in 17 parts of cold, and in 0.5 part of boiling, water, freely soluble in glycerin, but insoluble in alcohol. When borax is heated, it swells up, the water of crystallization being expelled, and at a red heat the anhydrous borax fuses to a transparent, colorless mass. 

When heated, borax fuses, loses w and swells into a wh porous mass. Finally borax melts(anhyd powd at 561°) and on cooling forms a clear glass. Borax beads fused in a loop of Pt wire are used as tests for oxides which dissolve in the bead and show characteristic colors... 

Synonyms borax glass disodium tetraborate anhydrous fused borax fused sodium borate sodium pyroborate sodium tetraborate anhydrous. 

Borates, tetra, sodium salt, anhydrous Borax, fused. See Sodium bo... 

Borate(l-), tetrafluoro-, potassium. See Potassium fluoborate Borate(l-), tetrafluoro-, tin (2+) (2 1). See Stannous fluoroborate Borate (1-), tetrahydro-, potassium. See Potassium borohydride Borax Borax, Borax decahydrate. See Sodium borate decahydrate Borax, fused. See Sodium borate Bordeaux RRN. See Pigment orange 43 Bordeaux F2R. See Pigment red 12... 

Borax Borax decahydrate. See Sodium borate decahydrate Borax, fused. See Sodium borate Bordeaux mixture... 

Titanium disiUcide [12039-83-7] is a silvery-gray, crystalline material that oxidizes slowly in air when heated to 700—800°C. It is resistant both to mineral acids (except hydrofluoric) and to aqueous solutions of alkaUes, but reacts with fused borax, sodium hydroxide, and potassium hydroxide. It reacts explosively with chlorine at high temperatures. 

Anhydrous Borax. Anhydrous borax is produced from its hydrated forms, borax decahydrate or pentahydrate, by fusion (Pig. 6). Low temperature calcining is usually an intermediate step to remove water of hydration. This material is fed to a refractory brick-lined furnace and fused to a mobile Hquid at about 1000°C. 

In general, the production of fused materials is much more energy intensive than that of hydrated products, and this difference is reflected in their prices. The primary producers are the United States Borax Chemical Corp. and the North American Chemical Co. Yearly fusion capacities for the two companies ate reported to be 86,000 and 36,000 metric tons B2O2, respectively (6). There is a plant in Turkey designed for the production of 60,000 t/yr of refined anhydrous borax from tincal ore (102). Small quantities of anhydrous borax have been produced in Argentina. 

Sihcon carbide is comparatively stable. The only violent reaction occurs when SiC is heated with a mixture of potassium dichromate and lead chromate. Chemical reactions do, however, take place between sihcon carbide and a variety of compounds at relatively high temperatures. Sodium sihcate attacks SiC above 1300°C, and SiC reacts with calcium and magnesium oxides above 1000°C and with copper oxide at 800°C to form the metal sihcide. Sihcon carbide decomposes in fused alkahes such as potassium chromate or sodium chromate and in fused borax or cryohte, and reacts with carbon dioxide, hydrogen, ak, and steam. Sihcon carbide, resistant to chlorine below 700°C, reacts to form carbon and sihcon tetrachloride at high temperature. SiC dissociates in molten kon and the sihcon reacts with oxides present in the melt, a reaction of use in the metallurgy of kon and steel (qv). The dense, self-bonded type of SiC has good resistance to aluminum up to about 800°C, to bismuth and zinc at 600°C, and to tin up to 400°C a new sihcon nitride-bonded type exhibits improved resistance to cryohte. 

Rose (2) A process for extracting gold from the residues from zinc production. The residues are fused with a mixture of borax and silica, and air blown through. The base metals oxidize and pass into the slag. 

Boric oxide is produced by treating borax with sulfuric acid in a fusion furnace. At temperatures above 750°C, the molten boric acid layer separates out from sodium sulfate. It then is decanted, cooled, and obtained in 96-97% purity. Boric acid above 99% purity may be obtained by fusing granular material. 

Preparation of Tin by Reduction with Charcoal. Prepare a mixture of 2.5 g tin(IV) oxide, 1 g of charcoal, and 0.5 g of ammonium carbonate. Transfer the mixture into a crucible and roast it in a muffle furnace. Write the equation of the reaction. Transfer the obtained bead into another crucible and fuse it with borax. After cooling, break the crucible and wash off the borax with hot water. 

Lastly, the gold is well washed, dried, and mixed with its own weight of bisulphatn of petassa, or a small quantity of borax and nitre, and fused in a Hessian crucible exposed ta a very strong beat. By this operation, the last portions of chloride of silver are removed, and a button of perfectly pure gold is obtained. 

When the pulverulent gold has entirely deposited, the liquid must be decanted or filtered off with the greatest precaution. Care must bo taken that not the smallest particle of the gold powder is allowed to pass away with tho liquid, A little hydrochloric acid, which must ho quite free from any admixture of nitric acid, is then to be poured upon the precipitate. This will remove any iron or other metallic impurities without dissolving the gold. The latter is then to be washed, at least six times, with successive portions of distilled waterj and lastly, it is transferred to a email porcelain Or platinum crucible, in which it is heated over a spirit lamp, till the last portions of water are expelled. It ought, in fact, to bo raised to a red heat, or even to be fused with a small quantity of borax and nitrate of soda, as formerly recommended, to expel the last traces of ohlorlde of silver. 

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