Glass, borosilicate

Much can be done with such standard apparatus in borosilicate glass as — Round-bottomed flasks 5 ml., 10 ml. and 25 ml. 

Boric acid is also an important boron compound with major markets in textile products. Use of borax as a mild antiseptic is minor in terms of dollars and tons. Boron compounds are also extensively used in the manufacture of borosilicate glasses. Other boron compounds show promise in treating arthritis. 

These borosilicate glasses may rate differently if subjected to excessive heat treatment. 

BSG = borosilicate glass PSG = phosphosilicate glass MOS = metal oxide semiconductor. 

Fractionally distd, then 35mL was sealed with about 7g KOH pellets in a borosilicate glass ampoule and heated at 135° for 48h. The ampoule was cooled and opened, and the liquid was resealed with fresh KOH in another ampoule and heated as before. This process was continued until no further decomposition was observed. The substance was then washed with distilled water, dried (CaS04) and distd. [Grafslein Anal Chem 26 523 1954.]... 

Soda-lime glass Borosilicate glass 70 SiOj, 10 CaO, 15 Na O 80 SiOj, 15 BjOj, 5 NajO Windows, bottles, etc. easily formed and shaped. Pyrex cooking and chemical glassware high-temperature strength, low coefficient of expansion, good thermal shock resistance. 

PVC, polythene and PTFE if moist gas is used Stainless steel, copper, nickel. Monel, brass, aluminium for dry gas <200°C. Borosilicate glass for low pressures. For moist gas, copper and polyvinylidene chloride plastics Monel and nickel Monel and nickel Most common metals so long as gas is dry... 

The carbon bed can be supported by glass wool, wire cloth, etc. Columns and fixtures can be constructed from glass, plastic, reinforced fiberglass, or metal. Borosilicate glass is commonly used. It is essential that all columns used in the pilot system have at least the same internal diameter. 

By virtue of its chemical and thermal resistances, borosilicate glass has superior resistance to thermal stresses and shocks, and is used in the manufacture of a variety of items for process plants. Examples are pipe up to 60 cm in diameter and 300 cm long with wall tliicknesses of 2-10 mm, pipe fittings, valves, distillation column sections, spherical and cylindrical vessels up 400-liter capacity, centrifugal pumps with capacities up to 20,000 liters/hr, tubular heat exchangers with heat transfer areas up to 8 m, maximum working pressure up to 275 kN/m, and heat transfer coefficients of 270 kcal/hz/m C [48,49]. 

Because borosilicate is a brittle material, its design stress is restricted to less than 7 N/mm. Borosilicate glass is attacked by hydrofluoric acid even when a solution contains only a few parts per million of fluoride ions, and at... 

Four column systems are available from Amersham Pharmacia Biotech that can be used to pack SEC media for various applications at the laboratory scale. These include C, XK, SR, and HR column systems. All of the laboratory-scale columns are constructed with borosilicate glass tubes. Columns for larger scale process applications include INdEX, BPG, EineLINE, BPSS, and Stack columns. The larger scale columns are constructed to meet stringent validation requirements for the production of biopharmaceuticals. Each of the column types are described. 

As a practical result, the amount of gel to be prepared for a preparative column must exceed the nominal volume of the final column by 10%. For the packing of production-scale columns the maximum pressure rate of the column has to be considered. The large columns consist mostly of borosilicate glass tubes with similar pressure stabilities. For example, a Superformance column with dimensions of 1000 mm in length and 50 mm in width is pressure stable up to 14 bar. Therefore, Fractogel EMD BioSEC should be packed with a... 

Many metal borates find important industrial applications (p. 140) and annual world production exceeds 2.9 million tonnes Turkey 1.2, USA 1.1, Argentina 0.26, the former Soviet Union 0.18, Chile 0.13Mt. Main uses are in glass-fibre and cellular insulation, the manufacture of borosilicate glasses and enamels, and as fire retardants. Sodium perborate (for detergents) is manufactured on a 550 000 tonne pa scale. 

Vitrification processes are being developed in several countries in which the dried waste is calcined and heated with ground glass frit to produce a borosilicate glass which can be stored or disposed of more permanently if there is agreement on suitable sites. 

Glass wool is made from borosilicate glass whose principal constituents are sand, soda ash dolomite. 

Taking the coefficient of cubical expansion of soda glass as about 0.000030 and of borosilicate glass about 0.000010 per 1 °C, Part A of Table 3.1 gives the correction to be added when the sign is +, or subtracted when the sign is —, to or from the capacity of a lOOOmL flask correct at 20 °C in order to obtain the capacity at other temperatures. 

Soda glass Borosilicate glass Soda glass Borosilicate glass... 

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