Method of recycling brazing sheet

Abstract

The present invention relates to a method of recycling aluminum clad materials. In particular, the method relates to recycling clad materials such as brazing sheet comprised of two or more aluminum alloys, by selective melting of one of the alloys. The feedstock is agitated during heating to allow separation of the molten alloy from the unmelted core, and the molten alloy is removed, such as by draining off during the process.

1 . A method of separating and recycling metallic clad materials comprising: 
 providing a feedstock of metallic clad materials having at least a first and a second metal, said first and second metals having different melting temperatures;    heating the feedstock in a furnace to effect melting of the metal having the lowest melting temperature, to produce at least a first molten metal and a second unmelted metal;    agitating the feedstock while heating to separate the first molten metal from the second unmelted metal; and    removing said first molten metal from the furnace.    
   
   
       2 . The method of  claim 1 , wherein said first and second metals are each an aluminum alloy.  
   
   
       3 . The method of  claim 2 , wherein said metallic clad material is a brazing sheet.  
   
   
       4 . The method of  claim 3 , wherein said brazing sheet is comprised of two or more alloys selected from the group consisting of 1XXX, 2XXX, 3XXX, 4XXX, 5XXX, 6XXX and 7XXX series aluminum alloys.  
   
   
       5 . The method of  claim 4 , wherein said brazing sheet is comprised of two or more alloys selected from the group consisting of 3XXX and 4XXX series aluminum alloys.  
   
   
       6 . The method of  claim 5 , wherein said melting is effected at a temperature of about 1145°-1180° F.  
   
   
       7 . The method of  claim 6 , wherein said melting is effected at a temperature of about 1150°-1160° F.  
   
   
       8 . The method of  claim 1 , wherein said agitating is effected for up to about 15 minutes.  
   
   
       9 . The method of  claim 1 , wherein said method is substantially a continuous process.  
   
   
       10 . The method of  claim 1 , wherein said method is carried out without the requirement of additional materials to improve separation.  
   
   
       11 . The method of claims  2  through  10 , wherein said separation results in molten and unmelted alloys having compositions that can be remelted into original alloy families without the need for substantial adjustment to the alloy composition.  
   
   
       12 . The method of  claim 1 , wherein said first metal is an aluminum alloy and said second metal is steel.  
   
   
       13 . The method of  claim 1 , wherein said first metal is zinc and said second metal is steel.