Jan. 05, 2018 - Stellar Materials LLC has introduced a new line of refractory products called the Thermbond 7200 Series that can substantially reduce the cost of most furnace repairs through its ability to provide consistent properties regardless of installation method. “Considerable amounts of multiple materials must be ordered and delivered to the job site because the installation methods that are required aren’t known until the furnace is shut down and can be closely inspected,” said Jens Decker, Vice President Engineering for Stellar Materials. “Stellar’s new Thermbond 7200 Series refractories provide excellent and consistent properties with all common installation methods – casting, pumping, gunning, ramming and shotcreting. A single formulation can be ordered with confidence that it can handle whatever installation conditions are encountered.”
Conventional refractories used in the petrochemical, aluminum, steel, cement and power industries come in different formulations, each of which provides specific properties when it is installed by a particular method. Often when a furnace is taken down for maintenance the installation method and materials needed for each repair changes. “In order to be certain that the repairs can be accomplished within the shutdown schedule, normal practice to is to order four or five different materials and have them all available,” said Tom Atkins, Senior Vice President- Worldwide Sales at Stellar Materials. “This approach ensures that the right material is on hand but the excess refractory ordered substantially complicates project management, material handling and storage requirements, and material return issues. This all adds to the cost of the repair.”
Thermbond 7200 Series are mixed with water for casting or pumping, with 7200 Liquid for gunning or ramming, or with 7200 Accelerator for shotcreting. Only two different liquids are required for all five major installation methods and the amount of liquid is roughly 5% by volume of the dry mix. Thermbond 7206 is a mullite based material and Thermbond 7206-N is the same basic formulation that is non-wetting to molten aluminum. Thermbond 7229 is a mullite based material with a 20% SiC addition. Thermbond 7229-N is the same formulation in a version that is non-wetting to molten aluminum. Additional bauxite-based formulations are currently under development and are expected to be released in early 2018.
Like most other Thermbond Refractories, Thermbond 7200 series are fast firing products that enable shorter dry-outs. Depending on the installation configuration, thickness, lining condition, and geometry, it can be fired in at up to 200 degrees C per hour with no holds. “We recently completely relined an aluminum chip melter with Thermbond 7206-N,” said Pedro Schroeders, Installation Manager for Stellar Materials. “The original lining used two materials, one for casting the floor, ramps and lower walls and the other for gunning the upper walls which are too high to cast. A foil barrier had to be installed to separate the two materials and there was considerable waste because the exact amount needed of each product was not clear until the job was underway. In relining the furnace with 7206, we used a single dry mix for both the cast and gunned areas. We saved considerable time by eliminating the foil barrier and much less material was wasted.”