Usage areas of Sodium Silica Fluoride

Sodium Silica Fluoride, which is used in the Glass and Enamel industry, also acts as a cogulant in latex. It can also be used in the production of zircon-based pigments, frit and ceramic enamels. It also has a limited area of ​​use in the textile and pharmaceutical industry.

Sodium fluorosilicate appears as white crystal, crystalline powder or colorless hexagonal crystals. It is odorless and tasteless. Its relative density is 2.68; It has moisture absorption feature. It can be dissolved in a solvent such as ethyl ether, but not in alcohol. Solubility in acid is greater than that in water. It can decompose in alkaline solution from which sodium fluoride and silica are produced. After firing (300 ℃), it is decomposed into sodium fluoride and silicon tetrafluoride.

At 25 degrees, the water solubility of sodium fluorosilicate is 0.78%. The addition of excess sodium sulfate or sodium chloride on production can increase the concentration of sodium ions in the system, thereby increasing the solubility product of fluorine silicate and sodium ions, so that sodium fluoride can be subjected to further precipitation. Sodium fluorosilicate is by-products in the production of calcium phosphate or fluoride salt in the aluminum plant. It usually appears as a white crystalline powder with low solubility (1% or less at room temperature) in water, and the solubility in water slightly increases with increasing temperature. The aqueous fluorosilicate aqueous solution is acidic (pH3). This is because the hydrolysis product contains hydrofluoric acid. Reducing the acidity of the solution facilitates the hydrolysis of sodium fluorosilicate. PH 3.5-3.55′ When it is lower than , the hydrolysis reaction is stabilized. When the pH is equal to 4, the hydrolysis reaction rate is important. When the pH is equal to 8-8.5, sodium fluorosilicate can be fully hydrolyzed and precipitated to appear as silica gel. Therefore, when sodium fluorosilicate is added to the water glass, in addition to the curing effect of the precipitation of silicon dioxide gel formed by the neutralization of sodium hydroxide in the water bath solution, sodium fluorosilicate itself is also a source of silica gel. The rate of hydrolysis reaction is important. When the pH is equal to 8-8.5, sodium fluorosilicate can be fully hydrolyzed and precipitated to appear as silica gel. Therefore, when sodium fluorosilicate is added to the water glass, In addition to the curing effect of precipitation of silicon dioxide gel formed by neutralizing sodium hydroxide in a water bath solution, sodium fluorosilicate itself is a source of silica gel. The rate of hydrolysis reaction is important. When the pH is equal to 8-8.5, sodium fluorosilicate can be fully hydrolyzed and precipitated to appear as silica gel. Therefore, when sodium fluorosilicate is added to the water glass, in addition to the curing effect of the precipitation of silicon dioxide gel formed by the neutralization of sodium hydroxide in the water bath solution, sodium fluorosilicate itself is also a source of silica gel. sodium fluorosilicate can be fully hydrolyzed and precipitated to appear as silica gel. Therefore, when sodium fluorosilicate is added to the water glass, in addition to the curing effect of the precipitation of silicon dioxide gel formed by the neutralization of sodium hydroxide in the water bath solution, sodium fluorosilicate itself is also a source of silica gel. sodium fluorosilicate can be fully hydrolyzed and precipitated to appear as silica gel. Therefore, when sodium fluorosilicate is added to the water glass, in addition to the curing effect of the precipitation of silicon dioxide gel formed by the neutralization of sodium hydroxide in the water bath solution, sodium fluorosilicate itself is also a source of silica gel.

Sodium fluorosilicate can be used as a raw material for the production of insecticide in agriculture, milk absorbent of enamel, corrosion production agent of opal glass, wood preservatives and other fluorides; as well as smelting of beryllium and aluminum and pharmaceuticals, leather and rubber industry. It can be used as coagulant in refractory material, as water glass binding agent. Because sodium fluorosilicate has a low water solubility, the reaction with water glass is slow and slow. This not only increases the structure, but also has a high density and strength of hardened products. It is generally used for bonding inorganic materials with water glass.