ABSTRACT
In the extraction and process metallurgy of metals and materials it is perhaps the reduction processes that are the centrally important unit operations. This chapter concerned with the reduction processes involved with these three niobium sources. The physicochemical principles of the reduction processes are also covered. The chapter incorporates such special processes as preparation of niobium via nitride decomposition, starting from niobium oxide and ferroniobium as sources of niobium. It describes some miscellaneous extractive processes for production of ferroniobium, niobium alloys, and niobium carbide. Reduction in a static bed system is carried out under a flowing inert gas atmosphere in a horizontally placed or vertical metallic reactor system. Niobium oxide reduction with calcium is one typical example of the metallothermic process. The reaction in a closed or sealed reactor or container, which very often is known as bomb reduction, essentially takes place very much in a confined system and the reaction proceeds under very near to adiabatic conditions.
