Abstract
For positive recycling method of cemented carbide scraps, this experiment used block-like scraps by machining process. Recycling process was used by tin impregnation method. This process characterized to react between Co and Sn by heat treatment, and produce brittle Co-Sn intermetallic compounds. Thereafter, it carried out by acid cleaning-stirring and physical milling or powdering. In order to obtain recycled WC powder, this process finished three treatments only. The results summarized as follows;
When the cemented carbides scraps were impregnated by molten Sn bath at 1323 K, it was found to produce a brittle Co-Sn intermetallic compounds. Therefore, Co phase in cemented carbides was transferred to these compounds. The surplus Sn was penetrated into cemented carbides. This treatment was able to get a remarkably brittle WC-Sn alloy. From stirring and cleaning by HCl solution after Sn impregnation, specimens were fractured easily and surplus Sn was resolved to molten alloy. In this experiment, it was able to recover about 60% WC fine powder from 1 to 5 μm.
