Process of refining of a metal bath in a crucible with oxygen blast at the top and crucible used.The invention consists essentially of providing in the bottom (15) of the crucible agitating gas injectors (15) located at least in a peripheral circular ring situated in immediate proximity to the refractory side wall. The injectors are preferably concentrated opposite the journals. Secondary injectors are, also preferably, provided in the bottom zone, intermediate between the ring and the center of the crucible.The invention makes it possible, in relation to the prior injection practice, to reduce the rate of dissolution of the agitating gas in the molten metal and then makes it possible to use a low-cost agitating gas, such as nitrogen, without risk of excessive nitridation of the bath.