Extraction of alkali metals and/or alkaline earth metals for use in carbon sequestration

Abstract

A method of extracting an alkali metal and/or an alkaline earth metal from a mineral including an alkali metal and/or an alkaline earth metal, or a rock containing the mineral, the method including contacting the mineral, with an aqueous composition including formic acid, and to their use in carbon sequestration.

1 - 31 . (canceled) 
     
     
         32 . A method of extracting an alkali metal and/or an alkaline earth metal from a mineral including an alkali metal and/or an alkaline earth metal, or a rock containing the mineral, the method including contacting the mineral, with an aqueous composition including formic acid. 
     
     
         33 . A method according to  claim 32  wherein the alkaline earth metal is chosen from calcium or magnesium. 
     
     
         34 . A method according to  claim 32  wherein the mineral is a silicate. 
     
     
         35 . A method according to  claim 32  wherein the mineral is chosen from olivine, enstatite, forsterite, serpentine and/or wollastonite. 
     
     
         36 . A method according to  claim 32  wherein the mineral is wollastonite. 
     
     
         37 . A method according to  claim 32  wherein the mineral, or the rock containing the mineral, is crushed prior to contact with the aqueous composition including formic acid. 
     
     
         38 . A method according to  claim 32  wherein the mineral, or the rock containing the mineral, is ground prior to contact with the aqueous composition including formic acid. 
     
     
         39 . A method according to  claim 32  wherein the mineral, or the rock containing the mineral, has an average particle size of between 1 μm to 250 μm. 
     
     
         40 . A method according to  claim 32  wherein the composition including formic acid has a pH of between 1 and 1.8. 
     
     
         41 . A method according to  claim 32  wherein the aqueous composition is at a temperature of between about 20° C. and about 95° C. 
     
     
         42 . A method according to  claim 41  wherein the aqueous composition is at a temperature of between about 75° C. to about 85° C. 
     
     
         43 . A process for the indirect carbonation of carbon dioxide the process including the following steps:
 extracting an alkali metal and/or an alkaline earth metal from a mineral, or a rock containing the mineral, according to  claim 32 ; and,    carbonating the alkali metal or alkaline earth metal with carbon dioxide to form a carbonate.   
     
     
         44 . A process according to  claim 43  wherein the carbonate is chosen from an alkaline earth metal carbonate and/or an alkali metal aluminium carbonate. 
     
     
         45 . Use of formic acid for the extraction of an alkali metal or an alkaline earth metal from a mineral, or a rock containing the mineral. 
     
     
         46 . Use according to  claim 45  wherein the alkali metal or the alkaline earth metal is subsequently carbonated with carbon dioxide to form a carbonate. 
     
     
         47 . Use according to  claim 45  wherein the mineral is a naturally occurring mineral. 
     
     
         48 . Use according to  claim 45  wherein the mineral is chosen from olivine, enstatite, forsterite, serpentine and/or wollastonite.