Lump silicate
Lump silicate is solid glassy substance derived from melting of quartz sand and soda ash or potash, they are added depending on which silicate, sodium or potassium, is needed. Sodium or potassium silicate, which are derived after agglomeration, are cooled and crystallized in the form of homogeneous, large, translucent, bluish-brown or weak green lumps, which are different in composition from the silicates included.
The lump silicate can be one-part or dual (mixed), it depends on the amount of salts included in lumps' composition, for example, sodium salts (soda ash) and potassium (potash).
Application area:
Soluble sodium silicate
Sodium lump silicate, like the liquid glass, is produced in high volumes because of the process energy intensity. The sodium silicate is more often used as raw material for sodium liquid glass preparation, but it is less interested as self additive agent for production of catalysts, adsorbents, carbon white, construction mixtures and as well as for the chemical production. The sodium silicate, manufactured according to the GOST R 50418-92, is the most popular in usage because of its relatively low cost. Usage of the liquid glass or the lump silicate as a component for any given product is determined by the production process.
Soluble potassium silicate
Potassium lump silicate, like sodium, is mainly used for liquid glass production. Considering high cost of raw material (potash), which is used for potassium lump silicate production, its cost price is significantly higher than the sodium silicate has. In this connection, the potassium silicate did not find mass application unlike the sodium, it is used providing absence of technical ability to use the sodium liquid glass and also for deriving of mixed sodium-potassium or potassium-sodium liquid glasses.
Dual (mixed) silicates: potassium-sodium and sodium-potassium silicates
They are used only for preparation of potassium-sodium and sodium-potassium liquid glasses, containing ratio potassium to sodium as 70/30 or vice versa.
Specifications
Soluble sodium and potassium silicates are characterized by the certain ratio of oxides - M2O and SiO2, where M - salts of Na (sodium) and K (potassium). Molecular ratio-silicate module SiO2/M2O is 2.3-3.6 for sodium silicate and 2.5-3.5 for potassium one.
| Parameter name | Sodium silicate | Potassium silicate |
|---|---|---|
| Silicate module | 2.3 — 3.6 | 2.5 — 3.5 |
| Mass fraction of silicon dioxide, % | 70.4 – 76.7 | 66.7-69.1 |
| Mass fraction of sodium/potassium oxide, % | 22.0 – 28.0 | 30.9-34.5 |
Governing document for the sodium silicate is the GOST R 50418-92, the potassium silicate is produced according to the manufacturer general specification.