Stable solution of sodium and iron silicate, process for preparing said solution and uses thereof
The present invention refers to a stable sodium and iron silicate solution that has a weight ratio of SiO 2 to Na 2 O from 1.5 to 2.5 and a total percentage of solids, expressed by the sum of SiO 2 and Na 2 O, from 20% to 55%. Said solution also has a soluble iron content, expressed by Fe, from 0.1% to 7%, and a water content from 38% to 79.9%. The present invention also refers to the process for preparing said stable solution of sodium and iron silicate, which comprises the steps of: (a) providing a siliceous material containing iron; (b) submitting said siliceous material containing iron to a hydrothermal treatment with caustic soda under high temperature and controlled pressure; and (c) filtering said reacted solution to separate the reacted portion of the hydrothermal treatment from the unreacted portion. Additionally, the present invention refers to the uses of said stable sodium and iron silicate solution.
1. A stable sodium and iron silicate solution having a weight ratio of SiO 2 to Na 2 O from 1.5 to 2.5 and a total percentage of solids, expressed by the sum of SiO 2 and Na 2 O, from 20% to 55%, said solution having a soluble iron content, expressed by Fe, from 0.1% to 1.0%, and a water content from 38% to 79.9%.
2. The stable sodium and iron silicate solution of claim 1 , wherein said solution is used as a binder agent for fines.
3. The stable sodium and iron silicate solution of claim 1 , wherein said solution is used in the manufacture of precipitated silica.
4. The stable sodium and iron silicate solution of claim 1 , wherein said solution is used as a binder for sand molds, as a deflocculant agent in the ceramic industry, or as binder for clays and adhesives.
5. The stable sodium and iron silicate solution of claim 1 , wherein said solution is used in the manufacture of silica gel.