Sodium and potassium silicates are referred to as solublesilicates because of
theirsolubility in water.They arenot affected by strong acids; however,this
phenomenon precludes the use of manyformulations in dilute acid service.
However, this disadvantage becomes an advantage for formulating singlecomponent powder systems. All that is required is the addition of water at
the time of use. Obviously,asthe name of these materials implies, the fillers
are pure silica.
The sodiumsilicatescan be produced over abroad range of compositions
of the liquidb inder. These properties and new hardening systems have
significantly improved the water resistance of somesodiumsilicate mortars.
These formulations are capable of resisting dilute as well as concentrated
acidsw ithout compromising physical properties.
The potassium silicate mortars are less versatilei nt erms of formulation
flexibility.T hey are, however,l ess susceptible to crystallizationi nh igh
concentrations of sulfuric acid so longa sm etal ionc ontamination
is minimal.
Potassium silicate mortars area vailable with halogen-free hardening
systems, thereby eliminating the remote potential for catalystp oisoning in
certain chemical processes.
The silica or silica sol typeo fm ortars are the newest of this class
of mortars. They consisto facolloidal silica binder with quartz fillers. The
principal difference compared to the other mortars is total freedom from
metal ion that could contribute to sulfation hydration within the mortar
jointsi nh igh-concentration sulfuric acidservice.
The workability and storage stability is comparable in the sodium and
potassium silicates. The silica materials are harder to use, less forgiving as to
mix ratio, and highly susceptible to irreversible damagebecause of freezing
in storage.
The chemical resistances of the variouss ilicate mortars are very similar.
Silicate mortars will fail when exposed to mild alkaline mediumss uch as
bicarbonateo fs oda. Dilutea cid solution, such as nitric acid,w ill have a
deleterious effect on sodium silicates unless the water-resistant type is used.
Table 1.9 shows the compatibility of various mortars with selected
corrodents.
1.4C hemical-Resistant MonolithicSurfacingsa nd Polymer
Concretes
The chemistryofmonolithic surfacings is an exploitation of the resin systems
used for mortars and grouts. Additional systemsw ill be included.
To reiterate, monolithic surfacings are installed at thicknesses of 1/16in.
(1.5 mm) to 1/2 in. (13 mm).P olymer concretes are installed at thicknesses
greater than 1/2 in. (13 mm). These materials are formidable corrosion
Corrosion of Linings and Coatings
16
CAT8247—CHAPTER 1—6/10/2006—11:59—SRIDHAR—XML MODEL B–pp. 1–42
theirsolubility in water.They arenot affected by strong acids; however,this
phenomenon precludes the use of manyformulations in dilute acid service.
However, this disadvantage becomes an advantage for formulating singlecomponent powder systems. All that is required is the addition of water at
the time of use. Obviously,asthe name of these materials implies, the fillers
are pure silica.
The sodiumsilicatescan be produced over abroad range of compositions
of the liquidb inder. These properties and new hardening systems have
significantly improved the water resistance of somesodiumsilicate mortars.
These formulations are capable of resisting dilute as well as concentrated
acidsw ithout compromising physical properties.
The potassium silicate mortars are less versatilei nt erms of formulation
flexibility.T hey are, however,l ess susceptible to crystallizationi nh igh
concentrations of sulfuric acid so longa sm etal ionc ontamination
is minimal.
Potassium silicate mortars area vailable with halogen-free hardening
systems, thereby eliminating the remote potential for catalystp oisoning in
certain chemical processes.
The silica or silica sol typeo fm ortars are the newest of this class
of mortars. They consisto facolloidal silica binder with quartz fillers. The
principal difference compared to the other mortars is total freedom from
metal ion that could contribute to sulfation hydration within the mortar
jointsi nh igh-concentration sulfuric acidservice.
The workability and storage stability is comparable in the sodium and
potassium silicates. The silica materials are harder to use, less forgiving as to
mix ratio, and highly susceptible to irreversible damagebecause of freezing
in storage.
The chemical resistances of the variouss ilicate mortars are very similar.
Silicate mortars will fail when exposed to mild alkaline mediumss uch as
bicarbonateo fs oda. Dilutea cid solution, such as nitric acid,w ill have a
deleterious effect on sodium silicates unless the water-resistant type is used.
Table 1.9 shows the compatibility of various mortars with selected
corrodents.
1.4C hemical-Resistant MonolithicSurfacingsa nd Polymer
Concretes
The chemistryofmonolithic surfacings is an exploitation of the resin systems
used for mortars and grouts. Additional systemsw ill be included.
To reiterate, monolithic surfacings are installed at thicknesses of 1/16in.
(1.5 mm) to 1/2 in. (13 mm).P olymer concretes are installed at thicknesses
greater than 1/2 in. (13 mm). These materials are formidable corrosion
Corrosion of Linings and Coatings
16
CAT8247—CHAPTER 1—6/10/2006—11:59—SRIDHAR—XML MODEL B–pp. 1–42