Under normal pressure, the boiling point of cadmium is only 770℃. It can meet the requirements of the process by atmospheric distillation. However, the atmospheric pressure distillation furnace is positive pressure. Once the furnace leaks, the cadmium vapor will diffuse in the working environment under uncontrollable conditions. In the case of serious cadmium poisoning and environmental pollution, it also causes fires; vacuum distillation is operated under vacuum under pressure, once the furnace loses pressure, cadmium will stop volatilizing and cadmium vapor leakage and a series of subsequent problems can be avoided. Therefore, the method of vacuum distillation is selected for crude cadmium distillation.

The crude cadmium is melted and vaporized under vacuum conditions of 570-590℃ and 50 Pa, and then partially refluxed and condensed. The pure cadmium vapor is condensed at 450℃to obtain refined cadmium with a cadmium content of 99.998%, and continuous production can be achieved.

Process flow：

Sponge Cd High purity Cd production process flow

Introduction of crude cadmium vacuum distillation furnace:

1. Multi-stage reflow is used to achieve high-precision separation of cadmium and impurities.

2. The silicon carbon rod is selected as the electric heating element, which is convenient to replace.

3. The furnace part adopts Q235 steel, the furnace body adopts Q345R steel, and its designed service life is to produce 3,000 tons of refined cadmium.

4, equipped with a weighing system, can accurately confirm the weight of the material in the furnace, reflecting the working conditions of the vacuum distillation furnace.

Vacuum distillation furnace technical parameters