Method of slag in the production process of ultra-low phosphorus steel and method of production of ultra-low phosphorus steel

摘要

Disclosed is a slag discharging method in a process of producing ultra-low phosphorus steel, which relates to the technical field of iron and steel smelting, and in which molten steel is mixed with lime first to produce basic slag; then converting is performed with oxygen to increase the oxidizability of the basic slag; and a carbon-containing reducing agent is finally added, so that in the process that the carbon is oxidized to release a large amount of carbon monoxide gas, phosphates are captured, and the basic slag is rapidly foamed and overflows from the opening of the steel ladle, so that conditions are no longer available for rephosphorization. The slag discharging method is simple and convenient to operate, does not have high requirements on the equipment, has relatively good dephosphorization effect, and can be used to prepare an ultra-low phosphorus steel containing less than 0.003% phosphorus. Also disclosed is a method for producing ultra-low phosphorus steel, which comprises the above-described slag discharging method in a process of producing ultra-low phosphorus steel, and refining and ingotting after slag discharge. The production method has good dephosphorization effect, has a low production cost, and can high-efficiently produce an ultra-low phosphorus steel containing less than 0.003% phosphorus.