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US 10,773,970 B2Granted
Preparation of lithium carbonate from lithium chloride containing brines
AssigneeTerralithium LLC
InventorStephen Harrison
Life of this patent
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Abstract
This invention relates to a method for the preparation of lithium carbonate from lithium chloride containing brines. The method can include a silica removal step, capturing lithium chloride, recovering lithium chloride, supplying lithium chloride to an electrochemical cell and producing lithium hydroxide, contacting the lithium hydroxide with carbon dioxide to produce lithium carbonate.
Claims13
A method of preparing lithium carbonate from a lithium chloride-rich stream, the method comprising the steps of:
- supplying a geothermal brine solution containing lithium chloride and silica to a silica removal step to produce a silica-lean lithium chloride-containing solution, wherein the silica removal step is operable to remove at least a portion of silica present in the geothermal brine solution;
- processing the silica-lean lithium chloride-containing solution through a lithium chloride capture step to obtain a lithium chloride-containing feed solution, wherein the lithium-chloride containing feed solution further comprises divalent ions;
- contacting the lithium chloride-containing feed solution with an ion removal medium to remove at least a portion of the divalent ions present in the lithium chloride-containing feed solution and produce a purified lithium chloride-rich stream having a reduced concentration of the divalent ions relative to the lithium chloride-containing feed solution;
- processing the purified lithium chloride-rich stream in an electrochemical cell to produce a lithium hydroxide-rich solution;
- contacting the lithium hydroxide-rich solution with carbon dioxide to produce a product stream comprising lithium carbonate;
- and
- separating the product stream to produce a lithium carbonate stream and a recycle stream, wherein the recycle stream is supplied to the electrochemical cell;
- wherein the recycle stream is acidified to a pH less than 4 prior to supplying the recycle stream to the electrochemical cell.
5 more elements
A method of preparing lithium hydroxide from a lithium chloride-rich stream, the method comprising the steps of:
- supplying a geothermal brine solution containing lithium chloride and silica to a silica removal step to produce a silica-lean lithium chloride-containing solution, wherein the silica removal step is operable to remove at least a portion of silica present in the geothermal brine solution;
- processing the silica-lean lithium chloride-containing solution through a lithium chloride capture step to obtain a lithium chloride-containing feed solution, wherein the lithium-chloride containing feed solution further comprises divalent ions;
- contacting the lithium chloride-containing feed solution with an ion removal medium to remove at least a portion of the divalent ions present in the lithium chloride containing feed solution to produce a purified lithium chloride-rich stream having a reduced concentration of the divalent ions relative to the lithium chloride-containing feed solution;
- and
- processing the purified lithium chloride-rich stream in an electrochemical cell to generate lithium hydroxide;
- wherein the silica removal step comprises oxidizing the geothermal brine solution using an oxidizing agent, and, after oxidation, adjusting the pH to a range from 5 to 6 to form precipitated compounds, wherein the precipitated compounds comprise silica;
- wherein the purified lithium chloride-rich stream is acidified to a pH less than 4 prior to processing the purified lithium chloride-rich stream in the electrochemical cell.
4 more elements
Dependencies are inferred from the claim text.