Methods and systems for utilizing waste sources of metal oxides

Abstract

Methods are provided for producing a composition comprising carbonates, wherein the methods comprise utilizing waste sources of metal oxides. An aqueous solution of divalent cations, some or all of which are derived from a waste source of metal oxides, may be contacted with CO 2 and subjected to precipitation conditions to provide compositions comprising carbonates. In some embodiments, a combustion ash is the waste source of metal oxides for the aqueous solution containing divalent cations. In some embodiments, a combustion ash is used to provide a source of proton-removing agents, divalent cations, silica, metal oxides, or other desired constituents or a combination thereof.

1 . A system comprising:
 a) a slaker adapted to slake a waste source of metal oxides   b) a precipitation reactor; and   c) a liquid-solid separator, wherein the precipitation reactor is operably connected to both the slaker and the liquid-solid separator, and further wherein the system is configured to produce carbonate-containing precipitation material in excess of 1 ton per day.   
     
     
         2 . The system of  claim 1 , wherein the system is configured to produce carbonate-containing precipitation material in excess of 10 tons per day. 
     
     
         3 . The system of  claim 1 , wherein the system is configured to produce carbonate-containing precipitation material in excess of 100 ton per day. 
     
     
         4 . The system of  claim 1 , wherein the system is configured to produce carbonate-containing precipitation material in excess of 1000 tons per day. 
     
     
         5 . The system of  claim 1 , wherein the system is configured to produce carbonate-containing precipitation material in excess of 10,000 tons per day. 
     
     
         6 . The system of  claim 1 , wherein the slaker is selected from a slurry detention slaker, a paste slaker, and a ball mill slaker. 
     
     
         7 . The system of  claim 1 , further comprising a source of carbon dioxide. 
     
     
         8 . The system of  claim 7 , wherein the source of carbon dioxide is from a coal-fired power plant or cement plant. 
     
     
         9 . The system of  claim 1 , further comprising a source of proton-removing agents. 
     
     
         10 . The system of  claim 1 , further comprising a source of divalent cations. 
     
     
         11 . The system of  claim 1 , further comprising a building-materials production unit configured to produce a building material from solid product of the liquid-solid separator.