TUNGSTEN RECYCLING WITHIN THE TUNGSTEN CARBIDE SCRAP USING THE MELTING METHOD AND A PREPARATION METHOD OF SODIUM TUNGSTATE APPLIED TO CERAMIC PIGMENT

摘要

The present invention relates to a method for recovering tungsten from waste sintered carbide operational and product scraps. The method uses alkali melting and hot water dissolving, does not using acid to reduce environmental burden, performs a purifying process at the same time of tungsten recovery, thereby manufacturing high-grade tungsten which is commercially available. The method includes the steps of oxidizing the scrapes under high-concentration oxygen atmosphere; melting the oxidized sintered carbide scrapes to alkali metals; selectively dissolving tungsten by hot water after the melting step.