Waste cadmium-nickel batteries contain a large amount of metal cadmium, nickel and a small amount of cobalt. If they are not recycled, they will not only pollute the environment, but also endanger human health (the most important harmful substance in used cadmium-nickel batteries is cadmium), and it will cause waste of resources.

Waste cadmium nickel battery treatment technology mainly includes fire treatment, wet treatment, combined wet and fire treatment technology and vacuum distillation. The wet process has a long process flow, and the pollution discharge may cause secondary pollution of the environment. The fire treatment technology has a large amount of treatment. However, if the cadmium vapor generated leaks, it will cause serious pollution to the environment.

The vacuum distillation method avoids the disadvantages of the fire method and the wet method. The process is short and the pollution caused by the environment is small. The purity of the cadmium recycled by one distillation can reach 99.9%. If further purification is required, the second stage distillation can be carried out.

The vacuum distillation method performs distillation separation according to different vapor pressures of metals such as cadmium, nickel, and cobalt at different temperatures.

The waste nickel-cadmium batteries are placed in a vacuum metallurgy furnace, and under the vacuum degree of 30 Pa or less, the distillation temperature is controlled at 550-900°C, so that the Cd in the nickel-cadmium batteries are volatilized into the gas phase, and can be condensed and discharged in a liquid to form the Ingots. While high-boiling metals such as Ni, Co, Fe, etc. in nickel-cadmium batteries are left in the distillation residue, achieving the purpose of nickel-cadmium separation and realizing the recycle of pure metal cadmium.