The wet process in the context of sodium silicate production is a method used to produce liquid sodium silicate directly from raw materials. This process is particularly favored when a liquid product is desired without the need for melting or high-temperature operations typically required in the furnace-based dry process.Wet Process Production Steps:

Raw Material Preparation:

Silica (SiO₂): Often in the form of finely ground sand or quartz.

Caustic Soda (NaOH): Sodium hydroxide is the primary source of sodium in the reaction.

Reaction Vessel:The wet process occurs in a reactor or autoclave, which is a high-pressure vessel designed to handle the reaction at elevated pressures and temperatures.The reactor is filled with a calculated amount of silica and sodium hydroxide, along with water.

Chemical Reaction:The mixture is heated under controlled pressure and temperature conditions.The reaction that occurs can be represented as: [ 2\text{NaOH} + \text{SiO}_2 + \text{H}_2\text{O} \rightarrow \text{Na}_2\text{SiO}_3 \text{(liquid)} + \text{H}_2\text{O} ]The heat and pressure facilitate the dissolution of silica into the caustic soda, forming liquid sodium silicate.Filtration:After the reaction, the resulting mixture may contain undissolved impurities or residual silica.The solution is filtered to remove any solid impurities, ensuring the purity of the liquid sodium silicate.

Concentration Adjustment:The concentration of the sodium silicate solution can be adjusted by either adding more water (dilution) or by evaporating excess water to achieve the desired concentration.The product’s specific gravity and modulus (ratio of SiO₂ to Na₂O) are critical parameters that are controlled during this stage.

Storage and Packaging:The final liquid sodium silicate is then stored in tanks and can be packaged for shipment in drums, IBCs, or tanker trucks, depending on customer requirements.