performance glaze minerals

1. Performance Glaze Materials
For fine ceramic glazes
improve glaze quality with reduced surface defects

2. Performance materials for improved glaze aesthetics
Sibelco has a wide range of specialist colourants, additives and specialist materials which are formulated to give exceptional
performance in glaze applications.
For the manufacture of fine ceramic glazes where surface finish and aesthetics form a key attribute of the final customer product
quality.
Sibelco Europe Minerals Plus supplies Casiflux® and Tital® which are derivatives of calcium and magnesium respectively and can
be added efficiently to glaze formulations as high performance silicate minerals to improve surface aesthetics.
The key features of the range are:
• Low colouring oxides
• Improved sintering
• Reduced CO2 evolution
• Finely micronized for direct glaze batch addition
Recommended glaze applications
Product Sanitaryware Tableware Tile
Casiflux   
Tital   
The Casiflux® range of products are produced from carefully selected wollastonite, a naturally occurring calcium silicate mineral.
The chemical composition of raw materials and product is closely monitored. Variation in chemical composition and particle
size distribution of Casiflux G is kept to a minimum. Casiflux G is produced in 2 grades ground to optimise glaze and ceramic
performance.
The Tital® range of products is produced from carefully selected high purity talc, which is a natural hydrated magnesium silicate.
Using our proprietary micronization technology we process the raw material to various particle size distributions. Properties of the
product are closely monitored and variation in chemical composition, whiteness and particle size distribution is kept to a minimum.
The products are low in iron content and have a high brightness. Tital 4591 can be used to introduce magnesium into ceramic
bodies and glazes
Chemical and Analytical Data - Typical values which do not represent a specification
CasiFlux CasiFlux Tital
Unit
G20 G38 4591
CaO Mass % 44 0.18
SiO2 Mass % 52 60.4
K2O Mass % 0.1 -
MgO Mass % 1.2 33.4
Al2O3 Mass % 0.45 0.04
Fe2O3 Mass % 0.37 0.25
Loss on ignition Mass % 1.7 5.5

3. Benefits of using Casiflux & Tital in Fine Ceramic Glaze Applications
Reduced glaze defects from gas evolution
Glaze surface defects such as pinholes are generally caused by trapped gases generated during the melting phases by the
decomposition of raw materials. for example; When calcium and magnesium carbonates are heated they liberate carbon dioxide.
CaCO3 CaO + CO2
MgCO3 MgO + CO2
CaMg(CO3)2 CaO + MgO + 2CO2
In theory, the temperature at which this happens is ~950°C, well below the fusion point of a typical sanitaryware glaze. However, in
practice some the gas generated gets trapped within the glaze as it starts to sinter at lower temperatures, causing bubbles. If these
bubbles are allowed to reach the surface of the glaze during the firing process then glaze defects such as pinholes or even blisters can
appear.
By reformulating glazes to use Casiflux G38 and Tital 4591, the problems associated with glaze bubble can be significantly reduced.
• By replacing calcite, dolomite and quartz with Casiflux and Tital, less gases are formed when the glaze fuses and melts.
• The liberated gases tend to form on undissolved particles of glaze (e.g. quartz or zircon). Casiflux and Tital will melt without leaving
residual particles to which any gases may adhere.
• When compared with a glaze formulated with calcite and dolomite, a Casiflux/Tital glaze will start to fuse at a higher temperature,
giving any evolved gases more time to escape.
Figure 1 – Typical sanitaryware glaze formulation and modfications using Casiflux and Tital
Formulations Base kg 1 kg 2 kg
Dolomite 49 49 -
Feldspar 466 466 466
Quartz 218 132 94
Kaolin 86 86 86
Zircon 162 162 162
Casiflux G38 - 165 197
Calcite 137 - -
Tital 4591 - - 35
Binder 3 3 3
Raw glaze 1,121 1,063 1,043
Total Fired
Glaze batch 1,000 1,000 1,000
(kg)
* formulation to achieve 1,000 kg fired glaze
As direct replacements i.e. keeping the same glaze chemistry (figure 1); not only is the incidence of bubbles reduced (figure 3), but there
are the added benefits of a slightly higher sintering/vitrification point, allowing more time during the firing process for gas to escape from
the body below the glaze and increased glaze flow at peak temperature (figure 2) making the glaze more forgiving of application faults
left on the surface prior to firing or possibly allowing for a reduction in feldspar or frit to produce the same flow.
Figure 2 – Flow of sanitaryware glaze surface
Results Base 1 2
Fusion Point 1100°C 1125°C 1125°C
Flow - +18% +19%
Figure 3 – Cross section of sanitaryware glaze surface
Base Formulation 1 CasiFlux 2 CasifFlux & Tital

4. mineralsplus.sibelco.com
over 220 production sites
in more than 40 countries
www.sibelcoceramics.com
e-mail: qualityceramics@sibelco.com