| The optimum conditions for the processing of WC/Co reclaimed powders with $quot;virgin$quot; properties has been studied. The experiments were carried out by contacting three kinds of cemented carbide scraps with molten zinc in an electric furnace under about one atmosphere of inert gas at temperatures from 650 to 800℃ and subsequently distilling the zinc from the reaction mass at temperatures from 700 to 950℃ From the experimental results, it has been found that the set of optimum conditions is a dissolution temperature of about 750-800℃ depending upon the cobalt content in the scrap, a distilling temperature of 850-950℃, a Zn/Co ratio of about 15 in the case of 7% Co-containing scrap or about 12.5 in the case of more than 8.5% Co-containing scrap, a dissolution time for about 2 hours, and a distillation time for about 3 hours. The $quot;virgin$quot; properties of reclaimed powders were confirmed in the case of the sintered products from 50% virgin- 50% reclaimed powders by the chemical analysis, the measurements of physical properties, and the tool wear tests. |
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