- Mineral calcination: rotary kilns producing aluminas, chamottes, kaolin, etc.
- Cement: rotary kilns and cyclones (roof and circular parts)
- Lime: vertical kilns, MAERZ kilns, rotary kilns
Choice of refractory material grade depends on the type of kiln (vertical or rotary), the operating conditions and the stresses exerted on the area to be brick-worked.
A number of parameters must be considered when selecting refractory linings:
- The type of calcined raw materials: clays, bauxites, clinkers, limestone, etc.
- The operating temperatures
- Starting and stopping cycles, if any
- The fuel(s) used: standard or replacement fuels, etc.
The grades proposed
In addition to its abrasion (chamotte and bauxite) and corrosion (andalusite – silicon carbide) resistant grades, BONY offers impregnation of refractory materials after baking so as to enhance their mechanical properties and corrosion resistance.
In the cement industry, rotary kiln operating parameters are not frozen and impact refractory lifetime.
Evolution in fuel types and, in particular, the increasing use of replacement fuels calls for greater attention as to choice and adaptation of refractory linings.
Consequently, basic refractory brickwork (magnesia, magnesia-spinel, magnesia-chromium, etc.) will necessarily evolve, and non-basic refractories (andalusites, silicon carbide, impregnation, etc.) may offer interesting answers, for example, for prevention of alkaline, sulphur and halogen attacks.
BONY’s R&D department has developed new grades satisfying the physico-chemical specifications required by its customers: reduction of thermal conductivity and porosity, reduction in Fe2O3 content, etc.