Tungsten Oxide

Blue tungsten oxide is one of the most important raw materials for the manufacture of tungsten powder. In China, there are three main methods for preparation of the blue tungsten oxide: APT closed calcination method, APT mild hydric reduction method and intrinsic reduction method. And the APT closed calcination method is the most used method. APT closed calcination method always keeps the furnace system with positive pressure in the heating process, preventing the air from entering the furnace. By this way, ammonia from APT pyrolysis splits into hydrogen and nitrogen. And in the weak reductive atmosphere, the blue tungsten oxide is produced. The entire process is confined in a rotary calciner. The usage and control of rotary calciner need cautious operation, as it is the main carrier of APT closed calcination process. Rotary hearth furnace is a rotary calciner with high automation, of which the ring-shaped bottom can be rotated. Generally it is divided into two sections to con...