Magnesium rechipping: Up and running

Dave Hostetler, general manager of TXM feedstock supplier Rossborough Walkerton, is fond of describing himself as "a straight-shooting Indiana farm boy." When he says, "We are the major TXM chip supplier in North America, and we will be dominant in the world," he does so with a disarmingly honest sense of conviction.

Through its growing network of global operations, and with the corporate support of folks like Thomas H. Bieniosek, vp of technology at the company’s Avon Lakes, OH headquarters, Rossborough offers a complete package of services to its customer base. Rossborough’s magnesium alloy TXM chip prices vary, depending on quantity requests from customers and raw material pricing. Hostetler tells us that alloy market prices have dropped 10 cents/lb since December 1999 because of all the new capacity coming onstream around the world.

Rossborough has a policy of sharing raw material price reductions and in-house productivity gains with its customers. And, as part of its full-service support, it buys back scrap from customers at a competitive price, which it then can toll-process.

Ready for Market Growth
The company has completed work on the full-production version of its magnesium TXM regrinding system. It is capable of a throughput of approximately 2 tons/hr. A box tipper dumps scrap into a hopper where a hydraulically driven pusher transfers it into a rotor and then into the grinding cutter (see diagram). The carbide cutting tips are about 2 inches thick and are designed to be easily replaced when worn. A screening system on top is designed to trap and prevent flyback. Regrind is collected and is subjected to the same rigorous quality testing Rossborough reserves for virgin chips.

The rotor runs at only 50 to 60 rpm. Its slow-motion operation and the cutter design eliminate dust generation. A conveyor underneath the system collects fines and transfers them to a station beside the system where they are collected for use in another of Rossborough’s business ventures.

The rechipping system is thoroughly equipped with magnetic separators to remove iron inclusions. Reground chips can be remelted or mixed with virgin for reuse. Rossborough’s computer-generated traceability documentation follows each lot of material through the entire grinding and regrinding process for one year.

If volume requirements warrant it, he says Rossborough can build a rechipping system at a customer’s facility. "We provide a competitive chip and a complete service to go along with each chip," the Indiana farm boy concludes.