Valoxy is an alumina-rich product that may be used in certain applications as an alternative to alumina and bauxite. Typical values of the main constituents are shown below (dry basis):
Typical mineralogical composition is as follows:
Spinelle MgAl2O4 30-45%
Corundum Al2O3 25-30%
Silica SiO2¬ 4-9%
Valoxy may replace bauxite in many applications including:
- Cement clinker
Valoxy has proven to be a valuable additive in cement manufacture.
Valoxy may be used to introduce alumina into the clinker burning process
of the cement kiln. Valoxy's high alumina content is important for the
formation of calcium aluminate complexes in the cement.
Moreover Valoxy's fluorspar content enables the formation of a calcium fluoride/calcium aluminate-based mineral important to cement production.
- Ceramic and refractory materials
Materials resistant to high temperature are made from materials such as alumina, bauxite, corundum, spinelle and aluminate cement. Valoxy may act as a source of alumina in ceramic and refractory applications. In addition, independent studies have demonstrated that Valoxy may replace fireclays in the production of clay products such as:
Flu lining material
- Compared to traditional chamottes such as quartz sand, Valoxy demonstrates performance and cost advantages. Valoxy maintains a thermally stable and open structure on firing and avoids the problem of micro-cracking associated with quartz inversion on cooling.
- Mineral wool
Alumina is added in the manufacture of mineral wool to reduce solubility of dust particles in lung fluids preventing bronchial problems for operatives.
- Calcium aluminates
Calcium aluminates are used in two main applications:
Synthetic steel refining slags to remove sulphur, phosphorus and
aluminium oxide from molten steel.
Calcium aluminates are produced by combining bauxite alumina with lime.
Benefits of using Valoxy:
- Stability: Valoxy offers reliable supply at a consistent price. By contrast alumina and bauxite are subject to significant fluctuations in availability and price.
- Cost savings: Valoxy may lower sintering and burning temperature and thereby reduce energy costs. Fluxing properties may reduce fuel consumption. Valoxy demonstrates cost benefits compared to traditional chamottes.
- Performance: Valoxy may reduce the setting time of cement and purification time with synthetic steel slags. Valoxy avoids micro-cracking on cooling in ceramics fired in the temperature range at 1,100-1,200C°
- Environment: Valoxy may reduce the emission of nitrogen oxides from the kiln