BARIUM SILICATE

BaSiO3 is orthorhombic with unit-cell dimensions of a = 5.6182(5), b = 12.445(1), c = 4.5816 . It is dimorphic with α-BaSiO3 stable below about 990°C but forms β-BaSiO3 above 1000°C. A 1:1 mol ratio of BaO–SiO2 fired at 850°C and 1050°C serves to form the two dimorphs.The enthalpy of solution of BaSiO3 in (3.15 mol/dm3 HF + 8.13 mol/dm3HCl) has been measured. From the results, the standard molar enthalpy of formation of BaSiO3 (s) was calculated. The value obtained was -1606.4±2.6 kJ/mol.

Colorless powder. Insoluble in water; soluble in acids.

Barium metasilicate (BaSiO3) is used in the paper and ceramic industries. 1) Prepare ceramic sintered body, mix Barium metasilicate, alumina, glass material and add oxide to form mixed raw materials under certain conditions, and then carry out the firing process at 850℃~1000℃. At this time, the monoclinic crystal Barium metasilicate with an average particle size of 0.3μm and less than 1μm and a specific surface area of 5m2/g to 20m2/g is mixed. In addition, alumina with an average particle size of 0.4μm~10μm and a specific surface area of 0.8m2/g~8m2/g is mixed and within the range of 10 to 25 % by volume relative to Barium metasilicate. The ceramic sintered body contains Barium metasilicate component, glass component, oxide added component and alumina particle, and has the microstructure of hexagonal barium feldspar in the periphery of the alumina particle. 2) Prepare a polystyrene based thermal insulation material, The polystyrene thermal insulation material comprises 10-25 parts of polystyrene, 6-15 parts of rock wool, 5-9 parts of nitrile rubber, 3-8 parts of vinegar propyl emulsion, 5-10 parts of polycaprolactone polyol, 4-7 parts of polytetramethylene ether diol, 8-13 parts of allyl polyethylene glycol, 4-10 parts of polypropylene alcohol and 4 to 8 parts of crushed barium metasilicate and 3 to 6 parts of barium phosphate are prepared respectively. The preparation method includes the following steps: Step 1: Separate Barium metasilicate and barium phosphate to crush; Step 2: Add polystyrene, rock wool, nitrile rubber, vinegar propyl emulsion, polycaprolactone polyol, stir evenly; Step 3: Add polytetramethylene ether diol, allyl polyethylene glycol, polypropylene alcohol, crushed Barium metasilicate and barium phosphate, then stir until evenly; Step 4: Sheet molding and pressing molding, pressing and cooling, polystyrene based insulation material. 3) Used to prepare a concrete preservative, including dense components 80-90 parts, bleed gas components 5-10 parts, anti-corrosion components 2-3 parts, the dense group is divided into silicate minerals, anti-corrosion group is divided into disodium phosphate and Barium metasilicate mixture, bleed gas components. Calcined disodium phosphate and Barium metasilicate at 1200℃ -1300 ℃ for one hour. Add appropriate amount of water into the cooked disodium phosphate and Barium metasilicate and grind them into the ball mill. After grinding, add silicate minerals and fatty alcohol ethenesulfonic acid and stir well. It can improve the sulfate resistance of concrete, and has significant social and economic benefits. Laboratory preparation of Barium metasilicate (BaSiO3) : Reaction of Na2SiO3 solution with BaCl2 solution to produce: Na2SiO3+ BaCl2= BaSiO3 (milky precipitation) ↓+ 2NaCl Reaction with barium nitrate and sodium silicate: Ba(NO3)2+Na2SiO3=BaSiO3 (milky precipitate) ↓+ 2NaNO3

Barium silicate films that are suitable for use as transmission media in integrated optical circuits. It is shown that the films, which can be produced with a wide range of refractive indices by suitable selection of the ratio of the target constituents, exhibit low optical attenuation. Hence it is used for integrated optical circuits. It is used in ceramics.