| Our family of refractory products provides a selective approach to solving problems in your toughest operating environment. |
 |
Melting and holding furnace
|
Melting furnaces are used to melt scrap or recycled aluminum, therefore a high heat input is required and the roof temperature can exceed 1100°C. Holding furnaces receive molten metal from either the primary reduction potlines or from the melting furnaces. They operate at a lower temperature.
Alkali chlorides and fluorides are often used as flux, but also to avoid bath oxidation and to help remove impurities in melting furnaces. These salts are very aggressive to the refractories.
In addition, molten AL is able to reduce many oxides found in the refractory linings, such as SiO2, Fe2O3, TiO2 to their metallic state. The by-product of this reaction is corundum and the accumulation of corundum on the refractory lining is a major problem in melting furnaces.
|
|
A combination of nitride bonded SiC bricks (
Cryston® CN190 ) and low porosity, chemically bonded alumina bricks (
Alfrax® PB111
) offers an optimal cost-performance compromize for ramp and hearth lining.
Saint-Gobain Ceramics also provides nitride bonded SiC (
Refrax® 20 and Cast Refrax®) tap out blocks, throat inserts and stopper rods.
Lauders systems for aluminium transfer and casting
We recommend our sintered fused silica
Prosil for high thermal shock resistance and low heat losses. But nitride bonded SiC sections (
Refrax® 20 ) are to be used for the high temperature and high erosion areas.
We also provide integrated filter bowls and pouring spouts made of Prosil and nitride bonded (Cast Refrax® ) die cast tubes. |
|
Degassing unit
|
Degassing rotors are used to produce the turbulence necessary to eliminate air in the melt and to introduce gas for alkali reduction while the melt is maintained at the appropriate temperature with immersion heaters. These two items, as well as the baffle plates, will benefit from the high toughness and chemical inertness of our nitride bonded SiC materials (Refrax® 20, Cryston® CN137 ). |