METHOD FOR PRODUCING HARD METAL GRANULATED MATERIAL

摘要

The invention relates to a method for producing a hard metal granulated material by carrying out wet milling and spray drying inside a spray tower -1- while using pure water as the liquid phase. According to the invention, the spray tower -1- is configured and operated in such a manner that the ratio of the amount of water, which is supplied over the wet slurry, in liters per hour ranges from 0.5 to 1.8 with regard to the tower volume in m<3>, and that a maximum of 0.17 kg wet slurry is supplied per m<3> drying gas, whereby the wet slurry has a solids content ranging from 65 to 85 wt. %. Under these conditions, the usually necessary addition of a water-soluble, long-chain polyglycol to the wet slurry before spraying in order to prevent the hard metal granulated material from oxidizing is eliminated.