PROCESS FOR THE PRODUCTION OF HARD METAL GRANULATE

摘要

A hard metal granulate is produced by wet milling and spray drying in a spray tower using pure water as the liquid phase. The spray tower is configured and operated in such a way that a ratio of the quantity of water added via the slurry (in liters per hour) to tower volume (in m<3>) is between 0.5 and 1.8 and in that a maximum of 0.17 kg of slurry is atomized per m<3 >of incoming drying gas. The slurry has a solid particle concentration within a range of 65-85% by weight. Under these conditions, the addition of a water-soluble, long-chain polyglycol to the slurry prior to spraying previously required in order to prevent oxidation of the hard metal granulate is no longer necessary.