Patent ID: 9677815
Date: 2017-06-13
CPC Classifications: C22B,F27B,F27D

Claim:
1. A method for controlling suspension in a suspension smelting furnace, wherein the method comprising using a suspension smelting furnace comprising a reaction shaft and a lower furnace at the lower end of the reaction shaft and a concentrate burner at the top of the reaction shaft, using a concentrate burner that comprises a pulverous solid matter supply device for feeding pulverous solid matter into the reaction shaft and that comprises a gas supply device for feeding reaction gas into the reaction shaft, feeding pulverous solid matter and reaction gas into the reaction shaft by means of the concentrate burner to produce a suspension of pulverous solid matter and reaction gas in the reaction shaft, collecting suspension in the lower furnace on the surface of a melt in the lower furnace, so that suspension that lands on the surface creates a collection zone at the surface of a melt in the lower furnace, feeding additionally to pulverous solid matter and additionally to reaction gas reducing agent into the suspension smelting furnace, wherein the reducing agent is fed in the form of a concentrated stream of reducing agent through the suspension in the reaction shaft onto the surface of the melt to form a reducing zone containing reducing agent within the collection zone of the melt, and wherein the reducing agent is fed at an initial velocity that is at least the feeding velocity of the reaction gas, feeding pulverous solid matter and reaction gas into the reaction shaft by means of the concentrate burner so that suspension produced by pulverous solid matter and reaction gas forms a suspension jet in the suspension shaft, wherein the suspension jet widens in the reaction shaft in the direction of the lower furnace and wherein the suspension jet has an imaginary vertical central axis, and directing a concentrated stream of reducing agent essentially in the direction of an imaginary vertical central axis of the suspension jet and in the vicinity to the imaginary vertical central axis of the suspension jet to prevent reducing agent of the concentrated stream of reducing agent from reacting with reaction gas prior landing on the surface of the melt.