Selective material recovery from natural brines

Abstract

Embodiments relate to methods for generating selected materials from a natural brine. A natural brine comprising at least a portion of a selected material is heated. CO 2 is added and mixes with the natural brine forming a mixture such that the CO 2 /P is a first predetermined value. The mixture is held so that impurities in the natural brine precipitate as solids leaving a second brine substantially comprising the selected material. The second brine is heated. CO 2 gas is injected into the second brine, mixing so that the CO 2 /P is a second predetermined value. The mixture is held so that the selected material precipitates out and are removed.

We claim: 
     
         1 . A method for extracting selected material carbonate from a brine, the method comprising the steps of:
 a. pumping CO 2  gas bubbles into a brine at ambient temperature and pressure whereby the CO 2  gas bubbles mix with the brine, thereby generating a CO 2  brine;   b. preparing a second brine comprising a selected material;   c. mixing the CO 2  brine with the second brine at an ambient temperature and pressure thereby forming a resultant mixture;   d. precipitating a selected material carbonate from the resultant mixture; and   e. removing the selected material carbonate precipitate.   
     
     
         2 . The method of  claim 1 , wherein the step of generating the CO 2  brine further comprises controlling number of CO 2  bubbles, size of CO 2  bubbles, pH, stirring, aeration, agitation temperature, and pressure. 
     
     
         3 . The method of  claim 1 , wherein the step of preparing the second brine further comprises controlling temperature, volume, seed, and pH. 
     
     
         4 . The method of  claim 1 , wherein the step of mixing the CO 2  brine with the second brine further comprises controlling volume ratio of the CO 2  brine and second brine and stirring. 
     
     
         5 . The method of  claim 1 , wherein the resultant mixture is further conditioned by controlling holding time, temperature, and pressure. 
     
     
         6 . The method of  claim 1 , wherein the selected material carbonate precipitate comprises at least one of a rare earth element, lithium, gold, iron, copper, and magnesium. 
     
     
         7 . The method of  claim 1 , wherein the selected material carbonate precipitate is lithium carbonate. 
     
     
         8 . The method of  claim 1 , wherein the resultant mixture is further concentrated by one or more of top pouring, skimming, or drying. 
     
     
         9 . The method of  claim 1 , wherein the step of removing the selected material carbonate precipitate from the resultant mixture comprises using at least one of a filter, gravity, centrifuge, and scraping. 
     
     
         10 . The method of  claim 1 , wherein the CO 2  gas bubbles have a diameter, wherein said diameter is ≤200 nm. 
     
     
         11 . The method of  claim 1 , wherein the pH of the CO 2  brine is ≤5.5. 
     
     
         12 . The method of  claim 1 , wherein the pH of the second brine is ≤8. 
     
     
         13 . The method of  claim 1 , wherein the resultant mixture formed by mixing the CO 2  brine with the second brine is in a volume ratio of 1.5:10 CO 2  brine to second brine. 
     
     
         14 . The method of  claim 1 , wherein the brine is a geothermal brine. 
     
     
         15 . The method of  claim 1 , wherein the brine is a produced water from oil and gas industries. 
     
     
         16 . The method of  claim 1 , wherein ambient temperature is room temperature and ambient pressure is approximately 1 atm. 
     
     
         17 . A method for extracting selected material carbonate from a brine, the method comprising the steps of:
 a. pumping CO 2  gas into a brine at ambient temperature and pressure whereby the CO 2  gas bubbles mix with the brine, thereby forming a resultant mixture, wherein the brine comprises a selected material that reacts with the CO 2  gas to form a selected material carbonate;   b. precipitating the selected material carbonate from the resultant mixture; and   c. removing the selected material carbonate precipitate.   
     
     
         18 . The method of  claim 17 , in which the step of mixing further comprises at least one of a batch and a continuous process. 
     
     
         19 . The method of  claim 17 , wherein unreacted CO 2  gas is cycled back into the resultant mixture. 
     
     
         20 . The method of  claim 17 , wherein the pumping, precipitating, and removing the selected material carbonate precipitate occurs underground.