Miller and Company LLC is the primary distributor of Mica slip plane products (produced by Cogebi) for the Induction Melting Industry. Mica slip plane material enhances the movement of refractory during thermal cycling because of its low coefficient of friction. Due to the high compressive strength, mica protects the integrity of the grout allowing the lining to expand and contract without abrading the coil grout.
Far less patching of coil grout is needed when mica is used. The mica does not stick to the grout and thus allows the easy removal of the spent refractory. Higher thermal conductivity allows the mica to conduct heat, on an average of 3.4 times faster than ceramic paper and 3.8 times faster than woven glass cloth. The removal of heat at the back of the refractory lining and interface, at the coil grout, promotes more loose back up silica. Mica reduces the risk of metal penetration to the coil as the crucible wears more uniformly and develops fewer cracks.
COGEBI 504 products are the world’s leading slip-plane products. Two grades are available for channel furnaces or coreless induction furnaces, 504-32-50 and 504-48-50. The grade used depends on your furnace size.
Material in slip plane coreless furnaces (push-out / non push-out) Gasket material for channel furnace inductors.
For added tear resistance, the Cogebi 504-48-34 is now available. The 504-48-34 has twice the tensile strength than the 504-32-50 or the 504-48-50.
Cogebi 504 Combi
For insulators of foundry ladles or for use of channel furnace as upper case insulators it is recommended to use the Cogebi 504 Combi.
Experienced technical assistance is available for selection and application. For additional information contact your local Miller and Company LLC Area Sales Manager. COGEBI 504 is available from your Miller and Company LLC warehouses for immediate shipment. For additional information COGEBI has a website at www.cogebi.com. A video is available upon request.
Mica Slip Plane Increases Efficiency of Coreless Furnace Lining Removal
In 1997, Shelco Foundries, a 90-employee ductile iron plant in Jacksonville, Alabama, was looking to improve the removal of the lining from its two 9-ton coreless furnaces. It decided to switch from its cloth to a mica slip plane and purchased the Cogebi 504 Mica from Miller and Company, LLC, Rosemont, Illinois.
Since the furnaces are not equipped with quick lining release, Shelco has discovered that the mica slip plane has cut the lining removal time by 50%. Jack Galbreath, plant manager, has found the mica easy to work with. “Just cut to length, place vertically against the coil grout, glue the seams and you are ready to reline,” he said. “When the spent lining is removed, the mica readily peels away from the grouted coil. When the old product was used, many hours were spent scraping and grinding away what was stuck to the coil grout. Then, the coil had to be patched.”
The mica slip plane product is used in coreless furnace operations to protect the coil grout with its high compressive strength. The products low coefficient of friction makes removal of the spent furnace lining easy.
Because of the mica’s high thermal conductivity, it allows the rapid transfer of heat through the coil. With nonexistent permeability, the mica reduces the migration of carbon monoxide through the lining. Upon cooling, this carbon monoxide is converted to carbon dioxide, which deposits on the coil and can lead to turn-to-turn arcing
Shelco has discovered that since it began using the mica, cracking at the upper rings of the furnace and patching of the coil grout almost have been eliminated, and there is more loose backup refractory, so the lining is running cooler with an increased life. The mica slip plane also helps protect the coil from iron fins. The mica slip plane is available for both coreless and channel furnaces.
Published in Modern Casting “Product Innovations” September 1999 issue.
For availability and proper application :
Please contact your local Miller and Company LLC Area Sales Manager.