Refractory products generally consist of a mixture of coarse and fine grains and a binding agent. The aim is to achieve the highest possible packing density, i.e. low porosity and high solidity. Ideally, the formula should show a steady grading curve with directly adjacent grain classes.
Calcined alumina in ground and unground form, as well as finely ground reactive alumina, form the fine grain range, while sintered products, such as tabular alumina or sintered spinel or the corresponding smelting products make up the coarse range.
- Comprehensive product portfolio
- Different grain fractions
- Application-specifi technical advice
Tabular alumina is a sintered, high-purity, alpha alumina with a bulk density between 3.5 and 3.65 g/cm³ and an aluminum oxide content of over 99.5%. During the sintering process, flat, tablet-shaped corundum crystals are formed, which are characterized by excellent thermo-shock behavior.
Typical application areas include refractory mixes and bricks, particularly for use in high-temperature applications, such as in the iron and steel industry. Further applications can be found in the petrochemical industry, e.g. in reactor linings, as well as in the oxide ceramic industry as a raw material for kiln furniture. In round form, the tabular alumina is also used as a filter bed material in aluminum production.
In the overview, you can find the various grain fractions available for the tabular alumina. The full overview of reactive alumina and calcined alumina can be found under Ceramics.
|T60/T64||-45μm LI (-325)|
|T60/T64||-45 μm STD (-325)|
|T60/T64||0-0.2 mm (-100)|
|T60/T64||0-0.3 mm (-48)|
|T60/T64||0-0.5 mm (-28)|
|T60/T64||0.075-0.3 mm (48-200)|
|T60/T64||0.2-0.6 mm (28-48)|
|T60/T64||0.5-1 mm (14-28)|
|T60/T64||0-1 mm (-14)|
|T60/T64||1-2 mm (8-14)|
|T60/T64||1-3 mm (6-14)|
|T60/T64||2-5 mm (1/4"-8)|
|T60/T64||3-6 mm (3-6)|
|T60/T64||5-10 mm (1/2-1/4)|
Sintered spinels are another common ingredient of refractory products. In addition to alumina-rich spinels, we also offer magnesia-rich spinels, which are used in magnesite refractory bricks, for example. High strength, resistance to changes in temperature and slag resistance make alumina-rich spinels particularly attractive for the iron and steel industry.
The following table lists the available grain sizes of our spinel products.
|SPINEL AR78||-20 μm|
|SPINEL AR78||-45 μm|
|SPINEL AR78||0-0.5 mm|
|SPINEL AR78||0.5-1 mm|
|SPINEL AR78||1-3 mm|
|SPINEL AR90||0.5-1 mm|
|SPINEL AR90||0-0.5 mm|
|SPINEL AR90||1-3 mm|
|SPINEL AR90||3-6 mm|
|SPINEL MR66||-90 μm|
|SPINEL MR66||0-1 mm|
|SPINEL MR66||1-3 mm|
As a hydraulic binder, calcium aluminate cement is especially important in demanding refractory concrete formulations. Its setting and sinter behavior, rheology and chemical resistance are controlled by the reactive CA phases. Calcium aluminate cements in refractory concrete formulas must also have excellent flow properties with little water consumption and good heat strength, as well as being quick to wet.
Our product range features various high-purity, 70% and 80% cements from ALMATIS.
|CA-14 M||70||medium setting time|
|CA-14 W||70||short setting time|
|CA-270||70||long setting time, extremly low water demand|
|CA-25 R||80||short setting time, contents deflocculant|
|Alphabond||calcium free hydraulic binder with low water demand|