Hydrothermal Mineral Extraction

Abstract

Described herein is a system and method for hydrothermal mineral extraction wherein the conditions surrounding hydrothermal systems are used advantageously to extract a mineral-rich brine. Specifically, hydrothermal fluid from ocean based or saline based hydrothermal systems contain a variety of minerals suspended in supercritical water and can be drawn up a well. As long as the water remains a supercritical fluid, the minerals remain largely in solution; however, as the hydrothermal fluid moves away from the this state, the water can cool and exit the supercritical state, causing the depositing or scaling of minerals along the walls of the well pipe. In the instant invention, non-supercritical conditions are rapidly induced onto the hydrothermal fluid such that the brine containing the minerals rapidly precipitates and forms a slurry which is then isolated from the water. Another aspect regards altering the chemistry of the fluid to precipitate the minerals. Another aspect of the invention is related to mineral-rich slurries isolated by this method and to specific minerals isolated therefrom.

1 . A method of hydrothermal mining comprising: 
 withdrawing a quantity of a supercritical hydrothermal fluid from a magma fluid source surrounding a hydrothermal vent, said hydrothermal fluid comprising a brine phase and a supercritical water phase; and    rapidly reducing the solubility of the hydrothermal fluid, thereby separating the hydrothermal fluid into water and a slurry.    
   
   
       2 . The method according to  claim 1  including pumping the hydrothermal fluid to increase flow rates.  
   
   
       3 . The method according to  claim 1  wherein the brine phase comprises dissolved mineral salts.  
   
   
       4 . The method according to  claim 1  including extracting valuable gases from the hydrothermal fluid.  
   
   
       5 . The method according to  claim 4  wherein the valuable gases include hydrogen and methane.  
   
   
       6 . The method according to  claim 1  wherein the solubility is rapidly reduced by shocking the supercritical fluid into a sub-supercritical state.  
   
   
       7 . The method according to  claim 6  wherein the supercritical fluid is shocked by lowering the temperature of the supercritical fluid, adjusting the pH of the supercritical fluid, adjusting the chloride content of the supercritical fluid, or a combination thereof.  
   
   
       8 . The method according to  claim 7  wherein the temperature is lowered using cold water.  
   
   
       9 . The method according to  claim 7  wherein the temperature is lowered just below a supercritical temperature of the fluid.  
   
   
       10 . The method according to  claim 1  including providing a tubing string to withdraw the hydrothermal fluid and reducing the solubility of the fluid adjacent a bottom end of the tubing string.  
   
   
       11 . The method according to  claim 10  including reducing the solubility of the hydrothermal fluid by injecting a solubility reducer into tubing string above an inlet of the tubing string which receives the hydrothermal fluid.  
   
   
       12 . The method according to  claim 10  including providing a first conduit in the tubing string for withdrawing the hydrothermal fluid and a second conduit in the tubing string for injecting a solubility reducer adjacent the bottom end of the tubing string.  
   
   
       13 . The method according to  claim 12  including injecting air into the solubility reducer within the second conduit for subsequent injection into the first conduit with the solubility reducer to provide lift to the hydrothermal fluid within the first conduit.  
   
   
       14 . The method according to  claim 1  including reducing the solubility by either adjusting the pH of the supercritical phase or adjusting the chloride content while maintaining temperature of the fluid near but just below a supercritical temperature of the fluid.  
   
   
       15 . The method according to  claim 1  including providing a production tubing string for withdrawing the hydrothermal fluid and locating a well head of the tubing string on land adjacent a body of salt water.  
   
   
       16 . The method according to  claim 1  including providing a production tubing string for withdrawing the hydrothermal fluid, reducing the solubility of the fluid adjacent a bottom end of the tubing string and isolating the slurry from the water adjacent a top end of the tubing string.  
   
   
       17 . A hydrothermal mining system comprising: 
 a tubing string for withdrawing a quantity of a supercritical hydrothermal fluid from a magma fluid source surrounding a hydrothermal vent, said hydrothermal fluid comprising a brine phase and a supercritical water phase; and    a solubility reducer for injection into the hydrothermal fluid for rapidly reducing the solubility of the hydrothermal fluid, thereby separating the hydrothermal fluid into water and a slurry.    
   
   
       18 . Minerals isolated by the method according to  claim 1 .  
   
   
       19 . A slurry containing a plurality of minerals isolated by the method according to  claim 1 .  
   
   
       20 . Hydrogen gas isolated by the method according to  claim 4.