Niobium Refining

Niobium powders, niobium sponges or brittle niobium strips can be produced by reducing niobium compounds, but these niobium products also contain a certain number of impurities, of which hydrogen, oxygen and nitrogen are particularly likely to make the niobium brittle, and therefore need to be further removed. There are two main purposes of niobium refining, i.e. purification and densification, and these two processes are generally completed simultaneously in industrial production.
Due to the strong affinity of niobium for oxygen and carbon, it is not possible to use containers made of oxygen-containing and carbonaceous materials, and it must be carried out under high-temperature and high-vacuum conditions, which not only complicates the refining process, but also has high requirements for equipment. Niobium refining methods are mainly vacuum sintering method, such as niobium vacuum sintering method refining, arc melting method, such as niobium vacuum arc melting, electron beam melting, such as niobium electron beam melting. One of the best purification effect of electron beam melting, the most widely used. In order to obtain the best purification effect, often using several refining methods with each other refining process, such as sintering of niobium produced by the strip, and then electron beam melting.