Cleaning method of clogging materials on RH lower groove and alloy feed opening

Abstract

The invention discloses a cleaning method of clogging materials on an RH lower groove and an alloy feed opening. In 20 min and within 20 min after RH production is ended, under the condition that thegroove temperature is higher than 1300 DEG C, an oxygen lance is adopted to blow oxygen to the lower groove; oxygen blowing is performed at three stages, namely the high stage, the middle stage and the low stage according to the distance between the muzzle of the oxygen lance and the bottom of the groove; the distance between the muzzle of the oxygen lance and the bottom of the groove at the highstage is larger than 5.5 m and smaller than 7.0 m, the distance between the muzzle of the oxygen lance and the bottom of the groove at the middle stage is larger than 5.0 m and smaller than 5.5 m, andthe distance between the muzzle of the oxygen lance and the bottom of the groove at the low stage is larger than 4.5 m and smaller than 5. 0 m; and the oxygen blowing speed is 1200-1500 Nm<3> / h. Theclogging materials on the lower groove and the alloy feed opening are melted by heat released by a chemical reaction between sufficient oxygen and Fe left on the inner wall of the groove and the alloyfeed opening; and by using the heat released by a Fe-O chemical reaction and combination with Gibbs free energy characteristics of FeO, Fe3O4 and Fe2O3, the clogging materials on the lower groove andthe alloy feed opening are melted, the refractory material damage is reduced, the condition that the alloy feed opening is blocked by the clogging materials is avoided, the production interruption caused by blockage of the clogging materials is avoided, and the service life of a refractory material in a vacuum tank is prolonged.

Description

technical field [0001] The invention relates to a method for cleaning metallurgical equipment, in particular to a method for cleaning nodules in the lower tank of the RH and the alloy discharge port. Background technique [0002] RH is a molten steel refining treatment technology jointly designed and developed by Ruhrsthal and Heraeus in 1959. This technology has been gradually expanded to decarburization, deoxidation, denitrification, desulfurization, chemical heating, changing the shape of inclusions in molten steel, controlling the composition of the end point, etc. through a single dehydrogenation. The reaction of carbon and oxygen in a vacuum state is violent, and its splash height can reach more than 10m, while the current domestic vacuum tank height is less than 11m, and the height of the alloy feeding port and the lower tank is usually less than 7m. The RH refining vacuum tank is composed of steel shell, silicon-calcium board layer, insulation layer, and working lay...

AI Technical Summary

Problems solved by technology

The RH refining vacuum tank is composed of steel shell, silicon-calcium board layer, insulation layer, and working layer. The working layer, especially the lower tank and the alloy discharge port, is easy to stick to steel and form nodules, and it will fall off to molten steel resulting in irregular composition. Qualified, if it is serious, the dipping tube or the alloy discharge port will be blocked and the production will be interrupted