Method for separating impurities out of feed stock in copper melts

Abstract

The invention relates to a method for separating impurities out of slags, dusts, minerals, preparation residues of minerals or of recyclings or remaining substances, subsequently called feed stock. In order to save energy and reduce costs, the inventive method is characterized by the combination of the following features: melting the feed stock containing the impurities; forming a copper melt; bring the feed stock into contact with the copper melt while adding reducing agents, preferably coke and/or coal; vaporizing, if required, existing volatile compounds such as metal chlorides; reducing metals of the feed stock more noble than copper in the copper melt, and; forming a slag with constituents of the feed stock to be purified that is less noble than copper.

1 . A method for separating impurities from slag, dust, minerals, preparation residues of minerals or of recyclings or remaining substances, subsequently called feed stock, the method comprising the following features:
 melting the feed stock containing the impurities;   forming a copper melt,   bringing the feed stock in contact with the copper melt whilst adding reducing agents, preferably coke or coal,   vaporising if required existing volatile compounds such as metal chlorides,   reducing metals of the feed stock more noble than copper in the copper melt and   forming a slag with constituents of the feed stock to be purified that are less noble than copper.   
   
   
       2 . The method according to  claim 1 , wherein a copper melt is formed with at least 50% copper. 
   
   
       3 . The method according to  claim 1 , wherein after reduction and taking up metals more noble than copper originating from the feed stock, the copper melt is subjected to a copper recycling process. 
   
   
       4 . The method according to  claim 3 , wherein the copper melt is recycled by blowing in oxygen. 
   
   
       5 . The method according to  claim 1 , wherein the copper melt is formed by melting scrap copper and/or by melting old or new scrap of copper and/or copper alloys and/or a part of the copper melt is formed by adding slag produced by blowing in oxygen into the copper melt. 
   
   
       6 . The method according to  claim 1 , wherein the slag formed from the feed stock to be purified is processed using adjuvants and/or waste materials to form clinker substitute and/or sand blasting abrasives. 
   
   
       7 . The method according to any one of  claims 1  to  6 , characterised in that dust from waste incineration is used as feed stock to be purified. 
   
   
       8 . The method according to  claim 1 , wherein dust from the iron and steel industry is used as feed stock to be purified. 
   
   
       9 . The method according to  claim 1 , wherein anodic sludge accumulating during electrolytic refining in the course of copper recycling is used as feed stock to be purified. 
   
   
       10 . The method according to  claim 1 , wherein substances less noble than copper are used as reducing agents. 
   
   
       11 . The method according to  claim 1 , wherein metallic waste materials such as aluminium-containing waste materials and/or iron-containing waste material are used as reducing agents. 
   
   
       12 . The method according to  claim 1 , wherein a reducing or oxidising atmosphere is adjusted above the copper melt. 
   
   
       13 . The method according to  claim 1 , wherein the feed stock to be purified together with the reducing agents are injected into the copper melt. 
   
   
       14 . The method according to  claim 1 , wherein the feed stock to be purified is applied to a hot copper block which has not yet melted and any metal chlorides that may be present are thereby vaporised. 
   
   
       15 . The method according to  claim 14 , wherein a halogenating atmosphere is adjusted, preferably using a chlorine-containing flushing gas. 
   
   
       16 . The method according to  claim 14 , wherein the copper block together with the feed stock to be purified is melted and reducing agents are introduced into the melt, preferably are injected via lances.