Silica fume and sodium silicate

May 18
07:58

2012

David Yvon

David Yvon

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The water glass is a soluble alkali metal silicate materials combining by alkali metal oxide and silicon dioxide. It is also known as sodium silicate. According to the types of alkali metals, sodium silicate can be divided into sodium silicate and potassium silicate.

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Their formulas are Na2O.nSiO2 and K2O.nSiOz. N is called as water glass modulus. It is the ratio of silicon oxide and alkali metal oxide molecules in the water glass.

Sodium silicate modulus of the important parameters of the water glass,Silica fume and sodium silicate Articles generally between 1.5-3.5. Modulus greater the water glass, solid water glass the more difficult to dissolve in water, n is 1, often with warm water can dissolve, increase n when the need hot water to dissolve, n is greater than to take more than 4 atm of steam can be dissolved in 3:00. Sodium silicate modulus greater the silica content is more, the water glass viscosity, easy decomposition of sclerosis, the bond strength increases.

Sodium silicate production has dry and wet methods: dry quartzite and soda ash as raw material, finely ground mix, melted in the furnace at 1300-1400 ° C, the press reaction to generate solid water glass dissolved in water and liquid sodium silicate. Quartzite powder and caustic soda, the wet production for raw materials, under 2-3 atmospheres pressure steam reaction in a high pressure steamer, and direct generation of liquid sodium silicate. Silicon powder can replace the quartz ore, to produce the modulus of water glass.

Silica fumes as a new metal powder material has widespread use in the refractory industry. Important role in the improvement of its unshaped refractory. Traditional refractories are a number of pores, micro-silicon gray filling in the pores, bulk density and lower porosity, the strength can be significantly enhanced. Silica fume has a strong activity, the formation of colloidal particles in water, adding an appropriate amount of dispersant can enhance mobility, improve casting performance. Silica fume is easy to form in the water-Si-OH groups, has a strong hydrophilic and activity can enhance the cohesion of the refractory, while greatly improved high temperature performance, and prolong the life of the refractory products.

Silicon powder has been widely used in the refractory industry for metal powder supplier. The practical applications are in the following aspects: as refractories instead of pure aluminum oxide mud. It can be an additive in the production of monolithic and shaped refractory products. Metal powder’s strength and high temperature performance is greatly improved. It is also used for combining coagulant in casting steel drums. Meanwhile, silicon powder can be found in other refractory products cohesion agent, binder and coagulant additives.Source:http://www.mhcmp.com