Microwave Calcination Tungsten Trioxide Preparation

Tungsten trioxide is an important intermediate product in the process of tungsten extractive metallurgy. The tungsten powder and tungsten main raw material-related are prepared usually by the calcining. Microwave calcination has an internal fast, selective calcination, the material can be overcome: the "cold center", energy-saving features, it is easy to control automatic implement, can effectively improve the quality rate and pass rate. Compared with the traditional production process of tungsten trioxide, microwave calcination time is short, low cost, high thermal efficiency, low energy consumption, and the powder is not easy to leak.

APT is a white crystalline, sheet-like or needle-like. It slightly dissolves in water, its solubility is less than 2% at 20 ℃I n water. The ammonium APT losing some crystal water and ammonia, or may be converted to ammonium metatungstate AMT in 220-280 ℃. It losing all crystal water and ammonia, completely transformed as a yellow tungsten trioxide heated at above 600 ℃. APT is mainly used to produce tungsten trioxide or tungsten blue oxide metal tungsten powder; tungsten material downstream products series, such as tungsten, tungsten and other electric vacuum material; there are alloy series, such as tungsten carbide, tungsten carbide, alloy blades, alloy drill, alloy molds and the like; other wear, pressure, mechanical equipment and other high-temperature components.

We put accurate weighing of the dried samples into the crucible, recording the weight of material as W₁. Using the modified multimode microwave calcined, recording time and power, removing after cooling weighing, recording data W₂. The W₁ minus W₂, we can get APT, calculate the actual weight loss rate (%). After the 4 minutes of microwave by calcination, ammonium APT of decomposition is 96.67%, and orthogonal experiments. The best conditions in the experimental are: microwave power is 650w, the calcination time is 4min, and the material weighs are 10g.