The invention relates to the field of
steelmaking. More specifically, the invention relates to a process for controlling
nitrogen increase in electric furnace
smelting. The invention provides a method for producing low-
nitrogen steel from electric furnace full waste steel. The method specifically comprises the steps that waste steel is loaded into an electric furnace, CO2 gas is injected into the electric furnace before and after loading, air is exhausted, and micro-
positive pressure in the electric furnace is kept. The method comprises the following steps: after an electric furnace forms a
molten pool, injecting limestone
powder at the top of the furnace with the injection amount of 60-80kg / t and the injection carrier gas of CO2 gas, after the electric furnace forms the
molten pool, injecting
oxygen and carbon
powder by adopting a carbon-
oxygen lance to make foamed
slag, injecting CO2 gas into the
molten pool to decarburize, produce two times of CO gas and intensify
denitrification, and during tapping of the electric furnace, protecting steel flow from ending with air by adopting CO2 gas, and feeding into the next process for
smelting after tapping of the electric furnace. Application proves that when the method is used for
smelting low-
nitrogen steel, nitrogen in the electric furnace can be controlled not to be increased, N is smaller than or equal to 0.003% after tapping of the electric furnace, the smelting rate of the low-nitrogen steel grade is increased, and low-carbon emission production of special varieties is achieved.