Producing lithium directly from lithium feed sources

Abstract

A process is provided for producing lithium directly from a lithium feed solution selected from the group consisting of lithium chloride brine, lithium sulfate spodumene liquor, lithium hydroxide, and a combination thereof. The lithium feed solution is provided in an electrolysis cell comprising a cathode suitable for electrolysis of lithium, and an anode. An ionizing electric current is provided to the electrolysis cell, thereby providing lithium metal at the cathode. The present process can advantageously streamline the lithium production process, reduce operating costs, and/or improve energy efficiency in production of lithium.

The invention is claimed as follows: 
     
         1 . A process for producing lithium directly from lithium containing brine or liquor, the process comprising:
 providing a lithium feed solution selected from the group consisting of lithium chloride brine, lithium sulfate spodumene liquor, and a combination thereof;   providing the lithium feed solution to an electrolysis cell comprising a cathode suitable for electrolysis of lithium, and an anode;   providing an ionizing electric current to the electrolysis cell, thereby providing lithium metal at the cathode.   
     
     
         2 . The process of  claim 1 , wherein the lithium chloride brine contains 1.5-18% lithium. 
     
     
         3 . The process of  claim 1 , wherein the lithium chloride brine contains 4-6% lithium. 
     
     
         4 . The process of  claim 3 , wherein the lithium chloride brine is prepared by evaporation in an evaporation pond. 
     
     
         5 . The process of  claim 4 , wherein the evaporation pond is selected from the group consisting of a solar evaporation pond and an electric evaporation pond. 
     
     
         6 . The process of  claim 4 , wherein the lithium chloride brine is returned from the electrolysis cell to the evaporation pond. 
     
     
         7 . The process of  claim 1 , wherein the lithium sulfate spodumene liquor contains 1-18% lithium. 
     
     
         8 . The process of  claim 1 , wherein the lithium sulfate spodumene liquor contains 1.5-18% lithium. 
     
     
         9 . The process of  claim 1 , wherein the lithium sulfate spodumene liquor contains 16-18% lithium. 
     
     
         10 . The process of  claim 1 , wherein the lithium sulfate spodumene liquor is provided from a reservoir, and the lithium sulfate spodumene liquor is returned from the electrolysis cell to the reservoir. 
     
     
         11 . The process of  claim 1 , wherein the lithium feed solution is prepared without removing boron or magnesium. 
     
     
         12 . The process of  claim 1 , wherein the lithium feed solution is continuously provided to the electrolysis cell, and the lithium metal is continuously produced at the cathode. 
     
     
         13 . The process of  claim 1 , wherein the temperature in the electrolysis cell for providing lithium metal is 15 to 40° C. 
     
     
         14 . The process of  claim 1 , wherein the temperature in the electrolysis cell for providing lithium metal is approximately 23° C. 
     
     
         15 . The process of  claim 1 , wherein the lithium feed solution has a pH of 3-9. 
     
     
         16 . A process for producing lithium directly from lithium hydroxide or lithium hydroxide monohydrate, the process comprising:
 providing an aqueous lithium feed solution selected from the group consisting of a lithium hydroxide solution, a lithium hydroxide monohydrate solution, and a combination thereof;   providing the lithium feed solution in an electrolysis cell comprising a cathode suitable for electrolysis of lithium, and an anode;   providing an ionizing electric current to the electrolysis cell, thereby providing lithium metal at the cathode.   
     
     
         17 . The process of  claim 16 , wherein the lithium hydroxide solution contains 1.5-18% lithium. 
     
     
         18 . The process of  claim 16 , wherein the lithium hydroxide solution contains 1-18% lithium. 
     
     
         19 . The process of  claim 16 , wherein the lithium feed solution is continuously provided to the electrolysis cell, and the lithium metal is continuously produced at the cathode. 
     
     
         20 . The process of  claim 16 , wherein the temperature in the electrolysis cell for providing lithium metal is 15 to 40° C. 
     
     
         21 . The process of  claim 16 , wherein the temperature in the electrolysis cell for providing lithium metal is approximately 23° C. 
     
     
         22 . The process of  claim 16 , wherein the lithium feed solution has a pH of 7-14.