Reaction #2006427

ord-0d58c1691db14888b5e5c52e78fc443e

Reaction equation

[K+].[K+].[K+].[K+].[O-][Si]([O-])([O-])[O-]
potassium silicate
O=[Si]([O-])[O-].[Na+].[Na+]
water glass
[Na+].[Na+].[Na+].[Na+].[O-][Si]([O-])([O-])[O-]
sodium silicate
O=[Si]([O-])[O-].[Na+].[Na+]
water glass
O=[Si]([O-])[O-].[Na+].[Na+]
sodium water glass
[K+].[K+].[K+].[K+].[O-][Si]([O-])([O-])[O-]
potassium water glass
→
O[Si](O)(O)O
silicic acid
O=[Si]([O-])[O-].[Na+].[Na+]
water glass

Reactants

[K+].[K+].[K+].[K+].[O-][Si]([O-])([O-])[O-]
potassium silicate
O=[Si]([O-])[O-].[Na+].[Na+]
water glass
[Na+].[Na+].[Na+].[Na+].[O-][Si]([O-])([O-])[O-]
sodium silicate
O=[Si]([O-])[O-].[Na+].[Na+]
water glass
O=[Si]([O-])[O-].[Na+].[Na+]
sodium water glass
[K+].[K+].[K+].[K+].[O-][Si]([O-])([O-])[O-]
potassium water glass

Reagents

None

Conditions

Detailed conditions
See reaction.notes.procedure_details.

Workup

  1. 1
    Otherto remove metallic ions

Procedure

Colloidal silica particles commonly used as polishing particles are made by a wet chemical method, which includes the steps of: preparing a dilute solution of a water glass (e.g., sodium water glass and potassium water glass, which are primarily composed of sodium silicate and potassium silicate, respectively) solution; passing the water glass solution through a cationic exchange resin to remove metallic ions, such as Na+ and K+, from the water glass solution to form an aqueous active silicic acid solution; adding a basic agent to the silicic acid solution for alkalization at appropriate temperature and pH value to conduct polycondensation of active silicic acid to form particles of colloidal silica; and ultra-filtering the particles of colloidal silica to obtain a silica sol. In consideration of safety, operating convenience, and production costs, the alkalization is usually conducted using sodium hydroxide or sodium water glass.

Source

DOI: 10.6084/m9.figshare.5104873.v1Patent: US08167684B2uspto-grants-2012_05