Method of separating metal from metallic starting materials using a hydrothermal reactor system

Abstract

The presently disclosed subject matter is directed to a method of hydrothermally treating metallic packaging, metallic labeling material, and scrap metal items. Particularly, the disclosed method initially comprises providing a metallic starting material. The metallic starting material is introduced to a reactor and processed at elevated temperature and/or pressure for a desired amount of time. As a result, the metallic portion of the starting material separates into a distinct layer that can be removed from the remainder of the starting material.

What is claimed is: 
     
         1 . A method of separating metal from a metallic starting material, the method comprising:
 loading the metallic starting material and a solvent into at least one reactor;   optionally adding catalyst, co-solvent, or both to the reactor;   applying heat and pressure to the starting material until the metal is separated from the metallic starting material, and   physically separating the metal from the starting material.   
     
     
         2 . The method of  claim 1 , wherein the metallic starting material comprises a metal and a substrate. 
     
     
         3 . The method of  claim 2 , wherein the substrate comprises paper, resin, or combinations thereof. 
     
     
         4 . The method of  claim 3 , wherein the resin is selected from polyethylene, polypropylene terephthalate, nylon, polyester, or combinations thereof. 
     
     
         5 . The method of  claim 1 , wherein the starting material has a thickness of about 5-200 micron. 
     
     
         6 . The method of  claim 1 , wherein the metal is tin foil, aluminum foil, tin, copper, gold, silver, a laminate of two metals, a metallized film, or combinations thereof. 
     
     
         7 . The method of  claim 1 , wherein the metal is an insulated wire. 
     
     
         8 . The method of  claim 7 , wherein the insulated wire is selected from insulated copper wire, electric house wire, thermoplastic-sheathed cable, aluminum jacketed Bronx cable with copper interior, and combinations thereof. 
     
     
         9 . The method of  claim 1 , wherein the solvent is selected from water, buffer, or combinations thereof. 
     
     
         10 . The method of  claim 1 , wherein the co-solvent is selected from one or more polar or non-polar organic solvents or oils. 
     
     
         11 . The method of  claim 1 , wherein the reactor is a batch, semi-continuous, or continuous hydrothermal reactor. 
     
     
         12 . The method of  claim 1 , wherein the catalyst is added at a concentration of about 0-1 weight % of the total weight of the input material. 
     
     
         13 . The method of  claim 1 , performed at a temperature of about 170° C. to about 310° C. 
     
     
         14 . The method of  claim 1 , performed at a pressure of about 150 to 1500 psi. 
     
     
         15 . The method of  claim 1 , wherein the ratio of starting material to water in the reactor is about 1:1 to about 1:200. 
     
     
         16 . The method of  claim 1 , wherein the reaction time is about 5 minutes to about 3 hours. 
     
     
         17 . The method of  claim 1 , wherein the physical separation comprises air density separation. 
     
     
         18 . The method of  claim 1 , wherein about 50-100 wt % of the metal in the starting material is separated from the starting material, based upon the total weight of the weight in the starting material. 
     
     
         19 . The metal separated by the method of  claim 1 . 
     
     
         20 . The metal of  claim 19 , selected from aluminum foil, tin, copper, gold, silver, or combinations thereof.