Process for producing a columbium addition agent

A niobium - bearing low - carbon ferrochromium addition agent is prepared by mixing high-carbon ferrochromium with an oxidic niobium-bearing material and a binder, e.g. chromic acid, iron or chromium formate solutions, compacting the mixture, and heating the compact in vacuum to cause evolution of carbon oxides, the rate of heating being controlled to maintain the temperature below 1500 DEG C. but sufficient to bring about sintering of the compact. The ferrochromium is initially comminuted to 0.07-0.037 mm., and the oxidic niobium material to 0.15-0.044 mm., and the molar ratio of oxygen in the latter to carbon in the former lies within the range of 1.0 to 1.2. The vacuum is less than 3 mm. of mercury. If tin is present in the initial niobium-bearing material, it may be eliminated as a volatile sulphide by incorporating a sulphur-bearing material or elemental sulphur in the reaction mass. The product contains in percentage by weight .Nb.5-20 .Cr.45-65 .Si.less than 2 .C.less than 0.5 .Sn.less than 0.25 .S.less than 0.03 .O.less than 3.2 .Fe.balance