calcined alumina in ceramic tiles
DESCRIPTION
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.TRANSCRIPT
USE OF ALUMINA IN THE CERAMIC TILES INDUSTRY
Marcelo Suster
FORN&CER- 2014 7ª. Edição
Itaforte Materiais de Alta Performance Telefone: +55 19 3023-5995/ 3023-9241 |
High alumina balls
Mill liners
Zirconite
Calcined aluminas
Global Presence
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
The Kreutz Zirconium Silicates are used in Ceramic Tiles,
Glass, Ceramics and others.
Zirconite -‐ Zirconium Silicate
!
Griding media and mill 9les ITAFORTE China produces high performance ball and is
the exclusive representative of German Kreutz.
Raw Materials
• Naturals – plastics – Non plastics
• Sinthetics – Non plastics
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
Alumina Sources
Source: Elaborated by Author
Bauxite Mine
Alumina Trihydrate
Calcined Alumina
Primary Aluminum
Smelter White, Pink and Ruby Fused Abrasive Grains
Crude White, Pink Ruby Fused Alumina
Chemical Industry
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
Paints, Paper Adhesives, Rubber Fillers & Coatings
Wallpaper, Waxes Ink, Paint, Paper, Rubber
Pigments
High Purity Alumina Substrates: Microchips, Catalysts
Synthetic Rubies, Sapphires Cutting Tools Polishing Compounds
Translucent Alumina Products
Welding Electrode Coating Fillers & Coatings Epoxy, silicone, Polyester
Glass, ceramics Refractories
Catalyst Support Beds Abrasives
Chorides
Fluoride
Sulfate
Aluminate
Zeolites and
Desiccants
FCC (fluid cracking catalysts) Molecular sieves Hydroteating catalysts
Fused minerals Calcined Al Sulfate
Source: Elaborated by Author
Low Medium High Fused
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
Aluminas Caracteristhics
Calcination grade
Source: Elaborated by Author
Productive process Calcined Alumina
• Bayer Process Bauxite Digestion Extraction Precipitation Calcination
Source: Elaborated by Author
Productive process Fused Alumina (corundun)
• Electrofusion Calcined alumina
– High surface area Melting Crushing Sieving Milling
Higgins Furnace
Source: Elaborated by Author
Aluminas- Morfology
Low Calcination High Calcination Fused
Source: Elaborated by Author
Application of Alumina in Ceramic Tiles
Glaze (Frits)
Engobe
Base
Anti-slipping
Ink
Source: Elaborated by Author
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
Aluminas Light Effects
Source: Elaborated by Author
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
Challenges
Shelf life & Beauty • Abrasive Wear • Chemical attack • Textural • Chipping/cracks • Swelling
Raw materials
Formulation 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
Tripolifosfato de Sodium (TPF)
0,1 0,1
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
Source: Elaborated by Author
Frits (glass) Al 3+- Network Stabilizer
Al3+
Source: Elaborated by Author
Effects of adding alumina
BRILHO ALVURA ABRASÃO-20
0
20
40
60
80
100
Valo
res
rela
tivos
BRILHO ALVURA ABRASÃO
Propriedades
FRITA MATE DE ZINCO
ALTA MÉDIA BAIXA CÓRINDOM
Source: Elaborated by Author
Alumina Properties
Fusibility
Bubles
Al2O3 - SiO2 - MgO - ZrO2 - CaO - ZnO - PbO - B2O3 - Na2O - K2O
Alumina
Source: Elaborated by Author
Viscosity
1260 1280 1300 1320 1340 1360 1380 14000
200
400
600
800
1000
1200 Albita Ortoclásio
Visc
osid
ade
(cP)
Temperatura (oC)
B2O3 - Na2O - K2O - PbO - ZnO - MgO - CaO - SiO2 - ZrO2 - Al2O3
Alumina Properties
Source: Elaborated by Author
Surface tension
PbO - B2O3 - K2O - Na2O - BaO -CaO - ZnO - ZrO2 - Al2O3 - MgO
Furo
Alumina Properties
Source: Elaborated by Author
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.
Thank you!!!