Use of alumina ceramic coatings Calcined and fused aluminas in ceramic tiles are used to confer both resistance to abrasion and resistance to chemical attack and also give the opacification effect . For this reason, alumina is used in compositions of engobes, glazes and inks. In its use in glazing, alumina has a wide range of functions it can be used to ensure the increase of the PEI coating to generate optical effects semi-gloss, matte, fusibility and control the expansion of the glaze. The addition of alumina can be given either in the grinding of raw materials or in the dispersion of the glaze / correction phase characteristics. The final effect of the alumina addition depends on its physicochemical characteristics. There are different types of calcined aluminas, each of which is produced by a different type of processing. Thus, the microstructural aluminas have physical differences, which give different behaviors in the preparation and firing of the glaze process.

1. USE OF ALUMINA IN THE CERAMIC
TILES INDUSTRY
Marcelo Suster
FORN&CER- 2014
7ª. Edição

2. Global Presence
High alumina balls
Mill liners
Zirconite
Calcined aluminas
Itaforte Materiais de Alta Performance
Telefone: +55 19 3023-5995/ 3023-9241 |

3. Hindalco
produces
Calcined
Alumina
Hydrate
and
with
different
levels
of
sodium
and
par9cle
size
distribu9ons.
OP1
Low
grade
calcined
alumina
S3
High
grade
calcined
alumina
S3G
High
grade
calcined
alumina-­‐
ground
(-­‐
325mesh).
S5
High
grade
calcined
alumina
with
low
soda
S5G
High
grade
calcined
alumina
with
low
soda
content
and
ground
(325mesh).
H10
Dry
hydrate.
H10G
Ground
or
jet
milled
dry
hydrate.
HU
Wet
hydrate

4. Zirconite
-­‐
Zirconium
Silicate
The Kreutz Zirconium Silicates
are used in Ceramic Tiles,
Glass, Ceramics and others.
!
Griding
media
and
mill
9les
ITAFORTE China produces
high performance ball and is
the exclusive representative of
German Kreutz.

5. Raw Materials
• Naturals
– plastics
– Non plastics
• Sinthetics
– Non plastics

6. Alumina Sources
Raw Materials
Feldspar
Kaolin
Bauxite
Minerals Feldspar and caulinitics Sands
Naturals & Nefeline-Sianite
Stones Quartz sands (as impurities)
Fonolite
Basalt
Granite
Agalmatolite
Calcined Alumina Al2O3
Hydrate Al(OH)3
Chemical Products Aluminum Nitrate Al(NO3)3
Sintethics Aluminum Sulphate Al2(SO4)3
By products Blast furnace slag
Source: Elaborated by Author

7. Bauxite Mine
Alumina Trihydrate
Calcined Alumina
Primary Aluminum
Smelter
Zeolites
and
Desiccants
Paints, Paper
Adhesives, Rubber Fillers & Coatings
Wallpaper, Waxes
Ink, Paint, Paper, Rubber
Synthetic Rubies, Sapphires
Cutting Tools
Polishing Compounds
Glass, ceramics
Refractories
White, Pink and Ruby Fused Abrasive Grains
Chemical Industry
Crude White, Pink
Ruby Fused Alumina
Detergent
Zeolites
Toothpaste
Cosmetics
Farmaceuticals
Deodorants
Antacids
Flame Retardant
Carpet Backing
Foam & Solid Plastics
Plastic Wire Insulation
Wallboard
Petroleum Refining
Catalyst Support, auto Exhaust
Activated Alumina
Claus Process Sulfur Recovery
Adsorbent for gases, liquids
Desiccants
Low Soda Alumina
Whiteware, fine China
Porcelain Insulators
Kiln Furniture
Pigments
High Purity Alumina
Substrates: Microchips, Catalysts
Translucent Alumina Products
Welding Electrode Coating
Fillers & Coatings Epoxy, silicone, Polyester
Catalyst Support
AbrasiveBs eds
Chorides
Fluoride
Sulfate
Aluminate
FCC (fluid cracking catalysts)
Molecular sieves
Hydroteating catalysts
Fused minerals
Calcined
Al Sulfate
Source: Elaborated by Author

8. Aluminas Caracteristhics
Low Medium High Fused
Calcination grade
Calcination temp. (°C) 1,000 1,100 1,250 2,200
Surface area
(m 2 /g)
45-75 9-11 0.9-1.4 0.7-0.9
Alpha phase content (%) <5 <10 >96 >99
Primary cristal size ( μ m ) <0.01 <0.1 3-4 1,000-3,000
Source: Elaborated by Author

9. Productive process
Calcined Alumina
• Bayer Process
 Bauxite
 Digestion
 Extraction
 Precipitation
 Calcination
Source: Elaborated by Author

10. Productive process
Fused Alumina (corundun)
• Electrofusion
 Calcined alumina
– High surface area
 Melting
 Crushing
 Sieving
 Milling
Higgins Furnace
Source: Elaborated by Author

11. Aluminas- Morfology
Low Calcination High Calcination Fused
Source: Elaborated by Author

12. Application of Alumina in Ceramic Tiles
Glaze (Frits)
Engobe
Base
Anti-slipping
Ink
Source: Elaborated by Author

13. Aluminas Light Effects
Alumina Type-calcination
grade/
electrofusion
Surface Area
m2/g
Crystal Size
μm
Effect
Low calcination 50-300 0,01-0,1 highly opacifier
Medium Calcination 8-15 0,1-1,0 semi-matizante
High Calcination 1-3 1-5 semi-bright
Fused 1 100-5000 Bright
Source: Elaborated by Author

14. Trends
• Valuation of the ceramic tiles
• Aesthetics
• Thermal Comfort
• Hygiene
• Multitude of uses
• facades
• living rooms
• dorms
• National standard of decor
• liberation of Europe
• international competitiveness

15. Challenges
Shelf life & Beauty
• Abrasive Wear
• Chemical attack
• Textural
• Chipping/cracks
• Swelling

16. Reformulation of engobes Aiming Replacement Zirconita
Paulo Sérgio Gonçalves, Marcelo Suster e Ronaldo dos Santos Flor
Cerâmica Industrial- Volume 5 - Número 1 - Janeiro/Fevereiro - 2000
Raw
materials
Formulatio
n standard
engobe
(%)
Formulation
of partial
substitution
with engobe
alumina (%)
Properties Standart with
alumina
Clay
Caulinítica
(%)
30 27 Opacity grade OK OK
Feldspar
Ortoclásio
(%)
25 25 Impermeability
grade
OK OK
Zirconite #
500 (%)
20 5 dilation °C –1
X 10-7
65 64
White Frits
- Zr
cs533 (%)
20 25 Reology/
outflow time
(s)
Cop for-4
12 12
Koalin (%) 5 12
Alumina
(%)
- 6,0
Quartz - -
Carboxi
Metil
Celulose
(CMC)
0,3 0,3
Tripolifosfa
to de
Sodium
(TPF)
0,1 0,1
Source: Elaborated by Author

17. Frits (glass)
Al 3+- Network Stabilizer
Al3+
Source: Elaborated by Author

18. Effects of adding alumina
FRITA MATE DE ZINCO
BRILHO ALVURA ABRASÃO
100
80
60
40
20
0
-20
Valores relativos
Propriedades
ALTA MÉDIA BAIXA CÓRINDOM
Source: Elaborated by Author

19. Alumina Properties
 Fusibility
Bubles
Alumina
Al2O3 - SiO2 - MgO - ZrO2 - CaO - ZnO - PbO - B2O3 - Na2O - K2O
Source: Elaborated by Author

20.  Viscosity
Alumina Properties
1260 1280 1300 1320 1340 1360 1380 1400
1200
1000
800
600
400
200
0
Albita
Ortoclásio
Viscosidade (cP)
Temperatura (oC)
B2O3 - Na2O - K2O - PbO - ZnO - MgO - CaO - SiO2 - ZrO2 - Al2O3
Source: Elaborated by Author

21. Alumina Properties
 Surface tension
Furo
PbO - B2O3 - K2O - Na2O - BaO -CaO - ZnO - ZrO2 - Al2O3 - MgO
Source: Elaborated by Author

22. Conclusion
The aluminum oxide is present in virtually all ceramic
products, and its presentation as a pure element is
particularly important in the ceramic tile industry, either in
the manufacture of glazed, engobes, chips, stains, anti-slip
coatings as well as in inputs for grinding. Checking all
these applications its high mechanical properties superior
abrasion resistance and chemical attack.

23. Thank you!!!
ms@itaforte.com