METHOD OF TREATING WASTE OF TUNGSTEN AND COBALT HARD-FACING ALLOYS Russian patent published in 1995 - IPC

FIELD: cutting tool reconditioning practice. SUBSTANCE: discarded single-point cutting tools of the BK8 grade are loaded into a furnace and kept at 1000 C for 1 hour in air. When the surface layer has oxidized, it is removed by shot blasting. The clean scrap is again loaded into the furnace and heated to 1000 C until complete oxidation takes place. A mixture of tungsten and molybdenum oxides is charged for reduction at 900 C into a furnace with controlled atmosphere of methane and hydrogen for 2 hours until carbides are formed. The methane concentration is maintained at 1.7 % during the treatment. After a 12-hour grinding, the contents of total and free carbon are determined. Dissolved raw rubber is added to the mixture before it is moulded and the product is sintered. EFFECT: the method enhances the strength of hard-facing alloys. 7 cl, 2 tbl