Extraction and recovery of metals under ambient conditions

Abstract

Methods for extracting a target metal from a mixed metal input are described. The method includes milling the mixed metal input with ammonium bicarbonate to form a milled solid product, aging the milled solid product, and leaching the target metal from the aged solid product.

1 . A method of extracting a target metal from a mixed metal input, comprising:
 milling the mixed metal input with ammonium bicarbonate to form a milled solid product;   aging the milled solid product to form an aged solid product; and   leaching the target metal from the aged solid product.   
     
     
         2 . The method of  claim 1 , wherein target metal is one or more of nickel, cobalt, and copper. 
     
     
         3 . The method of  claim 1 , wherein aging includes aging for up to 1 year. 
     
     
         4 . The method of  claim 1 , wherein milling includes low energy milling for 1 hour up to 5 hours. 
     
     
         5 . The method of  claim 1 , wherein leaching includes contacting the aged solid product with an aqueous leaching solution at a temperature less than 45° C. 
     
     
         6 . The method of  claim 1 , further comprising chelating ferric iron from the aged solid product with an anionic chelator to release nickel ions. 
     
     
         7 . A method of extracting a target metal from a mixed metal input, comprising:
 mechanochemically reacting the mixed metal input with ammonium bicarbonate to form a milled solid product;   waiting an aging duration to form an aged solid product from the milled solid product;   contacting the aged solid product with an aqueous leaching solution; and   isolating the target metal from the aqueous leaching solution.   
     
     
         8 . The method of  claim 7 , wherein the aging duration is at least one week. 
     
     
         9 . The method of  claim 7 , wherein contacting the aged solid product with the aqueous leaching solution includes moving the aqueous leaching solution or agitating the aged solid product in the aqueous leaching solution. 
     
     
         10 . The method of  claim 7 , further comprising separating the aqueous leaching solution from the aged solid product and adding ion exchange resin to the aqueous leaching solution. 
     
     
         11 . The method of  claim 7 , wherein isolating the target metal from the aqueous leaching solution includes one or more of electrowinning, cementation, ion exchange resin, crystallization, and solvent extraction. 
     
     
         12 . The method of  claim 7 , wherein a pH of the aqueous leaching solution is in a range of 7.0 to 9.9. 
     
     
         13 . The method of  claim 7 , wherein leaching the aged solid product leaches more target metal than leaching the milled solid product. 
     
     
         14 . A method of extracting nickel from a mixed metal input, comprising:
 low energy milling the mixed metal input with ammonium bicarbonate and milling media to react the nickel with the ammonium bicarbonate and form a milled solid product;   aging the milled solid product to form an aged solid product from the milled solid product, wherein the aged solid product is chemically different from the milled solid product; and   leaching the nickel from the aged solid product with an aqueous leaching solution comprising one or more of ammonium bicarbonate, a carboxyl metal extractant, and an amine metal extractant.   
     
     
         15 . The method of  claim 14 , wherein low energy milling includes jar milling. 
     
     
         16 . The method of  claim 14 , wherein one or more of the carboxyl metal extractant and amine metal extractant is included in the aqueous leaching solution in molar excess of the nickel in the aged solid product. 
     
     
         17 . The method of  claim 14 , wherein aging the milled solid product includes aging in relative humidity in a range of 40% to 85%. 
     
     
         18 . The method of  claim 14 , wherein the ammonium bicarbonate is added to the mixed metal input in a ratio of 0.5:1 up to 2:1. 
     
     
         19 . The method of  claim 14 , wherein leaching leaches greater than or equal to 90% of the nickel from the aged solid product to the aqueous leaching solution. 
     
     
         20 . The method of  claim 14 , wherein low energy milling includes dry low energy milling.