# US 2015/0147248 A1 · Process and equipment for producing pure lithium-containing solution > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0147248 A1 - Document ID: US20150147248A1 - Status: Published application - Kind: A1 - Application number: 14/402,178 - Filed: 2013-06-04 - Published: 2015-05-28 - Earliest claimed: 2012-06-05 - Assignees: Outotec (Finland) Oy - Applicants: Outotec (Finland) Oy - Inventors: Hannu Laitala; Janne Karonen; Liisa Haavanlammi - Web page: https://patentgrep.com/patent/US20150147248A1 ## CPC - C22B 26/12: Obtaining lithium - C01D 15/00: Lithium compounds - C01D 15/08: Carbonates; Bicarbonates - C22B 3/44: by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42) - C22B 7/006: {Wet processes} - Y02P 10/20: Recycling - C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS - C01D: COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; sulfides C01B17/22; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds other than ammonia and cyanogen, containing nitrogen and other non-metals C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; phosphides C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; cyanides C01C3/08; salts of cyanic acid C01C3/14; salts of cyanamide C01C3/16; thiocyanates C01C3/20) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract The invention relates to a process for producing a lithium-containing solution from a lithium-containing raw-material solution, by: a) precipitating a first part of magnesium and calcium from the lithium-containing raw-material solution, b) extracting a second part of calcium and magnesium from the lithium-containing solution by liquid-liquid extraction, a resultant product being a lithium-containing solution. The invention also relates to equipment for producing a lithium-containing solution from a lithium-containing raw-material solution, including a precipitation unit to remove a first part of magnesium and calcium and an extraction unit to receive the lithium-containing raw-material solution and to remove therefrom a second part of calcium and magnesium by liquid-liquid extraction, and control unit to control the operation of the precipitation unit. ## Claims ### Claim 1 A process for producing a lithium-containing solution from a raw-material brine solution, the process comprising the following steps: a) precipitation step, in which a first part of magnesium and calcium is removed from the brine solution by precipitation, b) extraction step, in which a second part of calcium and magnesium is removed from the lithium-containing solution obtained from the precipitation step by liquid-liquid extraction, a resultant product being a lithium-containing solution. ### Claim 2 (depends on 1) The process of claim 1, wherein the raw-material brine solution is a solution derived from a naturally occurring brine reserve. ### Claim 3 (depends on 1) The process of claim 1, wherein the first part of magnesium and calcium contained in the raw-material brine solution is removed by using sodium carbonate as a precipitant. ### Claim 4 (depends on 1) The process of claim 1, wherein the first part of magnesium and calcium contained in the raw-material brine solution is removed by using calcium hydroxide as a precipitant. ### Claim 5 (depends on 1) The process of claim 1, wherein the first part of the calcium and magnesium to be removed is 50 to 95% by weight of the total amount of calcium and magnesium in the raw-material brine solution. ### Claim 6 (depends on 1) The process of claim 1, comprising: assaying the composition of the lithium-containing solution prior to precipitation, determining, on the basis of said composition of the raw-material brine solution, the amount of a precipitant that removes from the raw-material brine solution said predetermined first part of magnesium and calcium, and dispensing said determined amount of precipitant into a precipitation unit. ### Claim 7 (depends on 1) The process of claim 1, comprising: assaying the composition of a feed into the precipitation step and/or the composition of the solution in the precipitation, determining, on the basis of said composition, the amount of a precipitant that removes from the raw-material brine solution said first part of magnesium and calcium, and dispensing said determined amount of precipitant into a precipitation unit. ### Claim 8 (depends on 1) The process of claim 1, wherein the composition of the precipitation-stage solution is measured during the precipitation process, and the precipitation process is discontinued and the solution is conveyed to a next process step, when the composition of the solution achieves a set value. ### Claim 9 (depends on 8) The process of claim 8, wherein the set value is achieved, when the total content of calcium and magnesium in the precipitation-stage solution is 50 to 95% by weight lower than the total content of calcium and magnesium in the raw-material brine solution. ### Claim 10 (depends on 1) The process of claim 1, wherein the precipitation step is continued until the total content of magnesium and calcium in the solution is dropped 50 to 95% by weight of the corresponding content in the raw-material brine solution. ### Claim 11 (depends on 1) The process of claim 1, wherein the precipitation step is continued until the lithium content in the solution is reduced at most 10% by weight of the corresponding content in the raw-material brine solution. ### Claim 12 (depends on 1) The process of claim 1, wherein the second part, i.e. the rest, of calcium and magnesium is 5 to 50% by weight of the total amount of the calcium and magnesium in the entire raw-material brine solution. ### Claim 13 (depends on 1) The process of claim 1, wherein an organic extractant is used in the extraction step. ### Claim 14 (depends on 1) The process of claim 1, wherein dialkyl phosphoric acid, such as di-2-ethyl hexyl phosphoric acid, or dialkyl phosphonic acid or dialkyl phosphinic acid or a mixture thereof is used in the extraction step. ### Claim 15 (depends on 1) The process of claim 1, wherein the extraction step includes a stripping step of calcium and magnesium, and a hydrochloric-acid-containing aqueous solution is used as a stripping solution, which hydrochloric-acid-containing aqueous solution containing calcium and magnesium, obtained after the stripping step, is conveyed back to an earlier process step. ### Claim 16 (depends on 1) The process of claim 1, which comprises at least one pre-treatment step of the lithium-containing raw-material solution selected from the group of evaporation of the lithium-containing raw-material brine solution, dissolution of calcium and magnesium carbonates in the lithium-containing raw-material solution or removal of boron from the lithium-containing raw-material brine solution. ### Claim 17 (depends on 1) The process of claim 1, wherein to the lithium-containing solution, obtained as a product, is added sodium carbonate to precipitate lithium carbonate. ### Claim 18 Equipment for producing a lithium-containing solution from raw-material brine solution, the equipment comprising: a precipitation unit arranged to remove a predetermined first part of magnesium and calcium from the raw-material brine solution by precipitating them, an extraction unit arranged to receive from the precipitation unit the raw-material brine solution and to remove therefrom a second part of calcium and magnesium by liquid-liquid extraction obtaining a lithium-containing solution as a product, and control means for controlling the operation of the precipitation unit to remove from the raw-material brine solution said predetermined first part of magnesium and calcium. ### Claim 19 (depends on 18) The equipment of claim 18, wherein the control unit is arranged to assay the composition of the raw-material brine solution prior to precipitation, or the composition of a feed into the precipitation unit, or the composition of the solution in the precipitation unit, to determine, on the basis of said composition, the amount of a precipitant that removes from the raw-material solution said predetermined first part of magnesium and calcium, and to dispense said determined amount of precipitant into the precipitation unit. ### Claim 20 (depends on 18) The equipment of claim 18, wherein the control unit is arranged to assay the composition of the lithium-containing solution prior to precipitation, to dispense the precipitant into the precipitation unit, to assay, during the precipitation, the composition of the lithium-containing raw-material solution and thereby to determine when the predetermined part of the magnesium and calcium will be removed from the raw-material solution. ### Claim 21 (depends on 18) The equipment of claim 18, wherein the precipitation unit comprises one or more consecutive precipitation reactors and the extraction unit comprises a liquid-liquid extraction unit. ### Claim 22 (canceled)