Sodium Silicate a Binder
for the 21st Century
Mike McDonald - National Silicates
Judy LaRosa Thompson - PQ Corporation
EVOLUTION OF SILICATE BASED BINDERS
THE PQ CORPORATION
PO Box 840
Valley Forge, PA 19482-0840
Silicates y Derivados, S.A.
PQ Australia Pty. Ltd.
PQ Silicates Ltd.
The 90’s have seen an increased demand in the performance requirements
of material being agglomerated. Today it is no longer good enough to have a
binder that adheres at a low cost. There is now a demand for binders to be
environmentally friendly and allow for better process efficiencies while still
being reasonably priced. In recognition of these increased performance
requirements, sodium silicate based formulations have been broadened to
offer increased performance. This paper discusses silicate chemistry, considerations when using silicate and some generic silicate binder formulations.
Binders have been described by Englelleitner1 as “an additive to the material
being agglomerated that produces bonding strength in the final product. A
binder can be a liquid or solid that forms a bridge, film or matrix filler or that
causes a chemical reaction.” This definition is very applicable to sodium silicate since silicates can be either liquids or solids. The diverse chemistry of
silicate means that it can bond by forming a film, reacting to form a matrix or
chemically binding with the material being agglomerated. An understanding
of the diversity of silicate will assist in formulation
2.0 SILICATE CHEMISTRY
2.1 WHAT ARE SODIUM SILICATES?
Soluble silicates are one of the oldest and most benign industrial chemicals.
The industrial beginnings of...