Silicates
In inorganic chemistry, soluble silicates are considered, thanks to their chemical and physical characteristics, to be among the most versatile and widely consumed materials. Sodium silicate is the most important product both for volumes and for fields of application. Potassium and lithium silicates are produced for those applications where special properties are required. The fields of use include from the chemical industry to cleaning products, from adhesives to the ceramic industry, to the foundry, to large underground works and more, that we will describe later. Silicates are, by their nature, environment friendly. If heated, they emit only water vapor and, if sprinkled in the ground or in water, they quickly depolymerize, dispersing as silicic compounds that are indistinguishable from the naturally-occurring ones. The constant care for the needs of customers, combined with the experience of Prochin Italia staff and the commitment to research, enables us to be always at the cutting edge in the production of basic and modified silicates that comply with the increasingly disparate and specific demands of the markets. Sodium and potassium silicates in aqueous solution may be obtained by two distinct ways:
- Melting process and subsequent dissolution
- Hydrothermal process or direct etching.
Melting Process
Sodium and potassium silicates in the vitreous state are produced by the melting chemical reaction of pure silica sand (SiO2) and sodium carbonate (Na2CO3) or potassium (K2CO3), inside special furnaces at above 1200 ° C temperatures; during the process there will be the formation of anhydrous silicate in the molten state and carbon dioxide in the gaseous state, according to the reaction:
M2CO3+ x SiO2 → M2O x SiO2 + CO2 (M = Na, K)
Then the anhydrous silicate is rapidly cooled and reduced to pieces. For its characteristic appearance it is called waterglass. Subsequently the same is dissolved in water. The operation occurs inside special autoclaves, under pressure and at high temperature. Once the desired concentration is reached, the silicate solution is purified by settling and filtration and it is subjected to the relative laboratory tests.
Hydrothermal Process
Process This process directly exploits the chemical etching to which the silica sand is subjected, respectively by an alkaline solution based on sodium hydroxide or potassium, in an aqueous environment according to the reaction:
2 MOH+ x SiO2 → M2O x SiO2 + H2O (M = Na, K)
The reaction occurs inside of special autoclaves, under pressure and at high temperature; in this case we directly obtain the aqueous silicate solution, that is purified by settling and filtration and subjected to the relative laboratory tests. Soluble silicates are inorganic compounds. The silicates find an extensive use since they are characterized a wide versatility . Sodium silicate is the most “important” product in terms of production volumes and fields of application. Lithium and potassium silicates are generally used for specific applications where a high performance is required. The field of application of silicates includes the chemical industry, cleaning products, adhesives, ceramics, foundries, tunneling and much more. Silicates have actually no impacts on the environment. When heated, they release vapour. If they are dispersed in the soil or in water, the depolymerization process begins immediately with release of silica not different from the naturally-occurring ones. Different grades of products are available within our range, designed for specific applications or peculiar requests by the R&D department, valid support to meet the customers’ needs.
Paper sector
Bleaching process of the pulp
Process of removing ink from waste paper
Chemical industry
Silicate solutions are widely used as a base for many chemicals or additives. Silicates are a source of silica used for the production of silica sol, silica gel, precipitated silica, titanium dioxide, and are also widely used in the production of zeolites, that in the field of cleaning products are used to replace phosphates.
Cleaning products’ sector
There are a lot of different advantages using Silicates in solution in cleaning formulas. They perform a protective action against corrosion, they offer a buffering capacity in a pH range of 9-12, they act as acid neutralizers, they have an emulsion and saponification effect of oils and fatty acids, they act as deflocculants and particle suspending agents, they are moreover suitable for the treatment of water hardness. For specific formulations and to prevent solubility problems it is advisable to use potassium silicate. Cleaning agents for industrial use are specifically designed also for the contact with oils and greases or for specific surface cleaning treatments. Prochin Italia silicates ensure an excellent saponification and deflocculation power.
Main applications
- Buffering and anticorrosive agents
- Oil sector
- Additives for drilling fluids
- Adhesives sector
- Adhesives for cardboard tubes, laminates
- Water treatment sector
- Flocculating agents
- Corrosion inhibitors
- Stabilisers of iron and manganese
- Level control of lead and copper
- Ceramics sector
- Dispersion agents
- Foundries
- Sand binders
- Building
- Cement setting’s accelerators
- Waterproofing and consolidation of the soil
- Water paints
- Welding sector
- Electrodes binders
- Horticulture industry
- Special fertilizers
- Antiparasitics