Method for quickly desulfurizing low-sulfur steel at low temperature under low iron-steel ratio

The invention discloses a low-temperature rapid desulfurization method for low-sulfur steel at a low iron-steel ratio, and belongs to the technical field of steel smelting. The desulfurization method mainly comprises earlier-stage deoxidation treatment and later-stage continuous twice desulfurization treatment, in the earlier-stage deoxidation treatment process, slag washing and deep deoxidation treatment are carried out by adding ferro-aluminum, lime and bauxite, later-stage refining desulfurization is facilitated, and continuous foaming slagging operation is added, so that the desulfurization efficiency is improved. In the later continuous two-time desulfurization treatment process, the power transmission gear and time are controlled to be matched with argon, and the desulfurization temperature is not lower than 1540 DEG C for accurate desulfurization. By using the desulfurization method provided by the invention, as long as the arrival temperature of the molten steel is not lower than 1515 DEG C, the gener