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Reclamation of Refractory Carbides from Carbide Materials.
Barnard-PG; Starliper-AG; Kenworthy-H
U S Pat 3 595 484 1971 Jul; :
Recovery of refractory carbides and the cementing agent from cemented carbides is accomplished rapidly and economically by treating the cemented carbides with molten Zn, followed by distillation of the zn from the mixture at elevated temperatures and under reduced pressure. Treatment with Zn, which forms a molten alloy with the cementing agent, breaks the bond between the carbide and the cementing agent. When the Zn is removed from the mixture by distillation, the resulting product consists of a mixture of the carbide and the cementing agent. The mixture is readily ground to a powder of particle size similar to that of the original ingredients and reused in preparation of the cemented carbide without further processing. The Zn vapors are readily recovered by condensing in a cooler zone of the furnace used in the distillation. The process can be used to recover refractory carbides, e.g., W, Ti, Ta, and Nb from cemented carbides.
U.S. Pat. 3,595,484; July 27, 1971; Chem. Abstr. 75:112,486T
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Content source: National Institute for Occupational Safety and Health Education and Information Division