Method for producing cathode copper

Abstract

Provided is a method for producing cathode copper. The method comprises a smelting step including feeding sulfidic copper bearing material and oxygen-bearing reaction gas into a suspension smelting furnace, to produce blister copper, a fire refining step including feeding blister copper into an anode furnace to produce molten anode copper, an anode casting step to produce cast anodes, a quality checking step for dividing cast anodes into accepted cast anodes and rejected cast anodes, an electrolytic refining step including subjecting accepted cast anodes to electrolytic refining in an electrolytic cell to produce cathode copper and as a by-product, spent cast anodes, and a recycling step for recycling anode copper of rejected cast anodes and anode copper of spent cast anodes.

1 . A method for producing cathode copper, wherein the method comprises
 a smelting step including feeding sulfidic copper bearing material such as sulfidic copper concentrate or finely ground copper matte and additionally oxygen-bearing reaction gas and slag-forming material into a reaction shaft of a suspension smelting furnace by means of a burner that is arranged at a top of the reaction shaft of the suspension smelting furnace, whereby sulfidic copper bearing material, oxygen-bearing reaction gas and slag-forming material react in the reaction shaft of the suspension smelting furnace into blister copper and slag, and collecting blister copper and slag in a settler of the suspension smelting furnace to form a blister layer containing blister copper and a slag layer containing slag on top of the blister layer in the settler of a suspension smelting furnace,   a fire refining step including feeding blister copper obtained in the smelting step into an anode furnace and fire-refining blister copper in the anode furnace producing molten anode copper in the anode furnace,   an anode casting step including feeding molten anode copper obtained in the fire refining step into anode casting molds to produce cast anodes,   a quality checking step for dividing cast anodes obtained in the anode casting step into accepted cast anodes and rejected cast anodes,   an electrolytic refining step including subjecting accepted cast anodes to electrolytic refining in an electrolytic cell to produce cathode copper and as a by-product, spent cast anodes, and   a recycling step for recycling anode copper of rejected cast anodes and anode copper of spent cast anodes,   wherein the recycling step including feeding rejected cast anodes and spent anodes into a mechanical breaker for mechanically breaking rejected cast anodes and spent cast anodes to produce anode copper grain and feeding anode copper grain into the reaction shaft of the suspension smelting furnace by means of copper grain feeding means.   
     
     
         2 . The method according to  claim 1 , further comprising feeding anode copper grain into the reaction shaft of the suspension smelting furnace at a distance from the burner. 
     
     
         3 . The method according to  claim 1 , further comprising feeding anode copper grain into the reaction shaft from the top of the reaction shaft of the suspension smelting furnace. 
     
     
         4 . The method according to  claim 1 , further comprising feeding anode copper grain into the reaction shaft of the suspension smelting furnace at a feeding that is situated between a connection point between the settler and the reaction shaft and the top of the reaction shaft 
     
     
         5 . The method according to  claim 1 , further comprising feeding anode copper grain into the reaction shaft of the suspension smelting furnace with the burner. 
     
     
         6 . The method according to  claim 1 , further comprising feeding additionally inert gas such as nitrogen into the reaction shaft of the suspension smelting furnace to prevent hot gases from the suspension smelting furnace from entering the copper grain feeding means. 
     
     
         7 . The method according to  claim 1 , further comprising a drying step for drying anode copper grain in a drying means prior feeding anode copper grain into the reaction shaft of the suspension smelting furnace. 
     
     
         8 . The method according to  claim 1 , further comprising using a screw feeder for feeding anode copper grain into the suspension smelting furnace. 
     
     
         9 . The method according to  claim 1 , further comprising feeding slag obtained in the smelting step into a slag cleaning electric furnace,
 by a slag treating step for treating slag in the slag cleaning electric furnace with reduction agent to in the slag cleaning electric furnace produce an electric furnace slag layer containing electric furnace slag and an electric furnace blister copper layer containing electric furnace blister copper,   by feeding electric furnace blister copper obtained in the slag threating step into an anode furnace,   by feeding electric furnace slag obtained in the slag threating step to a floatation means,   by a floatation step for subjecting electric furnace slag to flotation treatment to produce waste slag and slag concentrate of electric furnace slag, and   by feeding slag concentrate obtained in the flotation step into the reaction shaft of the suspension smelting furnace.   
     
     
         10 . The method according to  claim 1 , wherein the smelting step includes a first smelting step comprising feeding copper sulphide concentrate, oxygen-bearing reaction gas and slag-forming material into a reaction shaft of a first suspension smelting furnace by means of a burner that is arranged at a top of the reaction shaft of the first suspension smelting furnace, whereby copper sulphide concentrate, oxygen-bearing reaction gas and slag-forming material react in the reaction shaft of the first suspension smelting furnace into matte and slag, and collecting matte and slag in a settler of the first suspension smelting furnace to form a matte layer containing matte and a slag layer containing slag on top of the layer in the settler of the first suspension smelting furnace, and
 by the smelting step includes a second smelting step comprising feeding matte obtained in the first smelting step, oxygen-bearing reaction gas and slag-forming material into a reaction shaft of a second suspension smelting furnace by means of a burner that is arranged at a top of the reaction shaft of the second suspension smelting furnace, whereby matte, oxygen-bearing reaction gas and slag-forming material react in the reaction shaft of the second suspension smelting furnace into blister copper and slag, and collecting blister copper and slag in a settler of the second suspension smelting furnace to form a layer containing blister copper and a slag layer containing slag on top of the layer in the settler of the second suspension smelting furnace.   
     
     
         11 . The method according to  claim 10 , further comprising feeding anode copper grain in the recycling step into the reaction shaft of the first suspension smelting furnace. 
     
     
         12 . The method according to  claim 10 , further comprising feeding anode copper grain in the recycling step into the reaction shaft of the second suspension smelting furnace.