Novel method for minimizing reactant in the synthesis of sodium silicate solution from mixed-phase quartz-amorphous SIO2

Abstract

In this research, sodium silicate solution was synthesized by reacting silica from inorganic materials with NaOH. The determination of the amount of NaOH used in the reaction is calculated by considering the quantity of the crystalline (quartz) and amorphous phases of silica contained in the raw material used. Determination of the quantity of quartz and amorphous phases was carried out using a single peak method which is quite simple but is quite close to the actual quantity of the amorphous phase. In the hydrothermal system to synthesize sodium silicate solution from silica with a mixture of quartz and amorphous phases, an optimum dissolving effectiveness value of 98% can be achieved under dissolution conditions in an autoclave heated at a temperature of 250 °C for 6 hours with a silica:aquadest weight ratio of 1:5 and 1 stoichiometric NaOH added to the quartz phase plus 0.5 stoichiometric to the amorphous one. With this calculation method, saving of NaOH solvent can be made which are proportional to the quantity of the amorphous phase involved in the reaction. The amount of NaOH needed to make sodium silicate solution can be saved by a maximum value of 50% when using amorphous materials.

Keywords

• Odium silicate solution
• Quartz
• Amorphous
• Crystallinity
• NaOH
• Effectivity of dissolution