Potassium Fluorosilicate CAS 16871-90-2

Introduction to Potassium Fluorosilicate

Potassium Fluorosilicate is an inorganic crystalline compound with a stable lattice that releases active fluorine species under elevated temperature conditions. It presents as a white, odorless crystalline powder at room temperature. The salt shows very low solubility in cold water and decomposes in hot water or alkaline environments.

Industrial production uses controlled crystallization to deliver consistent particle size and purity grades. The compound acts as a fluorine donor in high-temperature processes, supporting oxide removal and melting point modification across silicate and metallurgical applications.

Potassium Fluorosilicate Chemical & Physical Properties

Applications of Potassium Fluorosilicate

Aluminum brazing fluxes: Formulated into Nocolok-type brazing fluxes for aluminum heat exchangers and automotive radiators. It dissolves stubborn aluminum oxide layers at operating temperatures, allowing filler metal wetting and forming leak-proof, high-strength joints free of post-braze corrosion.

Glass and ceramic glazes: Added to frits and ceramic glazes as an opacifying agent and auxiliary flux. It reduces the melting temperature of silicate matrices and generates light-scattering crystalline phases, producing bright opaque white finishes on sanitary ware and decorative tiles.

Magnesium alloy metallurgy: Applied as a protective cover flux during magnesium alloy melting and casting. The molten salt barrier prevents atmospheric oxygen from contacting reactive magnesium melts, cutting metal loss and improving ingot surface quality.

Storage & Safety Precautions for Potassium Fluorosilicate

• Store in tightly sealed, moisture-proof packaging in dry warehouse areas. Extended exposure to high humidity triggers slow hydrolysis, releasing trace hydrogen fluoride and causing powder caking.
• Avoid dust inhalation and direct skin or eye contact during dry handling. Wear N95 respirators, safety goggles and nitrile gloves during blending and bulk transfer.
• Keep separated from strong alkaline substances and hot aqueous systems to prevent uncontrolled decomposition and fluoride release.

Potassium Fluorosilicate FAQ

Q: How does Potassium Fluorosilicate (K2SiF6) improve aluminum brazing?

A: It acts as a key active flux component, dissolving aluminum oxide at brazing temperatures to support strong, leak-proof joint formation.

Q: Why do glassmakers add Potassium Fluorosilicate to ceramic glazes?

A: It serves as both opacifier and flux, lowering silicate melt points and creating light-scattering phases for bright opaque white finishes.

Q: What safety precautions apply to K2SiF6 powder handling?

A: Wear N95 masks, safety goggles and nitrile gloves to avoid dust irritation. Store in moisture-proof packaging to prevent hydrolysis and fluoride release.