Clean and rapid smelting method in an electric arc furnace with full scrap steel

A clean and rapid smelting method in an electric arc furnace with full scrap steel, wherein

• online dynamic switching for different mediums including a pure gas, a carrier gas A with a recarburization powder, a carrier gas B with a dephosphorization powder in an injection mode is utilized, to finish a process of blowing in turn below a molten steel level of a molten pool in different stages of smelting for the different mediums;
• the process of blowing in turn comprises:
• in a stage of recarburizing and fluxing, injecting the carrier gas A with the recarburization powder into the molten pool to improve a carbon content of molten steel in the molten pool, and to improve a flow velocity of the molten steel, wherein the molten steel has formed the molten pool, and accelerating a melting process of the full scrap steel by carburization, wherein the carbon content of the molten steel in the molten pool reaches 0.40%-2.0% after the melting process of the full scrap steel is completed;
• in a stage of high efficiency dephosphorization, injecting the carrier gas B with the dephosphorization powder into the molten pool to improve kinetic conditions for the high efficiency dephosphorization, wherein the high efficiency dephosphorization in the electric arc furnace is achieved by systematic dephosphorization of slag particles in a molten state, to make a phosphorus content of the molten steel equal to or less than 0.010%;
• in a stage of deep denitrogenation, injecting O2 or a gas mixture of O2 and CO2 into the molten pool to intensify decarburization in the molten pool, and effectively removing nitrogen in the molten steel by a large number of CO bubbles produced by a metallurgical reaction in the molten pool;
• and
• in a stage of a smelting endpoint, injecting the carrier gas B with the dephosphorization powder to prevent the molten steel from rephosphorization, then Ar into the molten pool, to homogenize compositions and a temperature of the molten pool, wherein the carbon content of the molten steel is equal to or more than 0.10%, the phosphorus content of the molten steel is equal to or less than 0.004%, and a nitrogen content of the molten steel is equal to or less than 0.005%;
• wherein the online dynamic switching refers to that the switching between the mediums is controlled by a control system and is performed according to the different stages, wherein the word online in the online dynamic switching refers to that the switching between the mediums is controlled by a control system, and the word dynamic in the online dynamic switching refers to that the switching between the mediums is performed according to the different stages.