METHOD OF STEEL SMELTING, DEOXIDATION, ALLOYING AND TREATMENT Russian patent published in 2010 - IPC C22B9/00 

FIELD: metallurgy.

SUBSTANCE: proposed method comprises loading the burden made up of metal scrap and fluxes, forcing natural gas and air or oxygen from below to smelt the burden by gas-air or gas-oxygen flame, equalising temperature and chemical composition of melt volume, adding slag-forming constituents, shutting off feed of natural gas and air or oxygen, and blowing the melt by inert gases from below. In melting, ladle-furnace is inclined to drain primary slag. Natural has and air or oxygen are forced via cooled gas-air or gas-oxygen nozzle made up of tubes inserted one into another and arranged in furnace gate valve pouring cup hole and dusted by dry refractory sand. Natural gas is fed via furnace outer tube, while air or oxygen is fed via inner tube. Ladle-furnace is closed by cover with electrodes jointed to bubbling washer to smelt additionally the burden by electric arcs. After smelting, primary slag is drained from ladle-furnace, move the latter into initial position to feed therein fluxing additives to form secondary slag. Now, blowing by inert gases is performed from below along with boiling, deoxidising, alloying, deep sulphur removal, dephosphorisation, homogenisation of chemical composition and temperature of finished steel.

EFFECT: higher efficiency and quality, lower production costs.

2 dwg