Process for depleting calcium and/or iron from geothermal brines

Abstract

This invention relates generally to processes for extracting iron and/or calcium from geothermal brines.

We claim: 
     
         1 . A method of depleting calcium from a geothermal brine solution, said method comprising:
 (a) contacting the geothermal brine solution with a QL reagent to create a reaction solution, wherein the QL reagent comprises a quaternary ammonium compound, a hydrogen ion exchange reagent, and an organic solvent, wherein the reaction solution comprises an organic phase and an aqueous phase, and wherein the reaction solution is maintained at a temperature in the range of about 180° F. to about 230° F.;   (b) extracting calcium into the aqueous phase, wherein the organic phase becomes a calcium-depleted geothermal brine solution;   (c) separating the aqueous phase from the organic phase; and   (d) removing additional calcium from the calcium-depleted geothermal brine solution by extracting the calcium-depleted geothermal brine solution with an aqueous acidic scrubbing solution to form a scrubbed organic phase, wherein the aqueous acidic scrubbing solution has a manganese concentration of about 40 g/L to about 70 g/L.