The divisional application that the application is application number is 201080067082.1, the applying date is on April 23rd, 2010, denomination of invention is the patent application of " method being prepared Quilonum Retard by lithium chloride ".
Embodiment
In a broad aspect, as described herein is the method for being produced Quilonum Retard by the solution of chloride containing lithium.
As used herein, salt brine solution refers to the aqueous solution of basic metal and/or alkaline-earth metal, and wherein the concentration of salt can be changed to saturation point from trace.Usually, the salt solution being suitable for described method here can for comprising the aqueous solution and the natural brine of basic metal or alkaline earth metal chloride, bromide, vitriol, oxyhydroxide, nitrate and analogue.Salt solution can be obtained by natural origin, such as Chilean salt solution or Salton Haiti thermal source salt solution, geothermal brine, seawater, mineral salt solution (such as lithium chloride or Repone K salt solution), an alkali metal salt salt solution and industrial brine, the industrial brine such as reclaimed by ore leaching, ore dressing etc.Present method is equally also applicable to the lithium chloride solution of artificial preparation.
Therefore, the inventive method comprises by comprising the solution preparation of monovalent cation (comprising lithium), polyvalent cation, univalent anion and multivalent anions and reclaiming Quilonum Retard.
With reference to accompanying drawing 1, in an embodiment of the inventive method, provide the solution 30 of chloride containing lithium.The concentration of the solution 30 of chloride containing lithium can be about 1-42wt%, is preferably greater than about 10wt%, more preferably greater than about 25wt%.In an alternate embodiment, the concentration of the logistics 30 of chloride containing lithium is greater than about 10wt%.
In certain embodiments, before being supplied to electrolyzer 32, the solution 30 of chloride containing lithium can optionally stand purifying or enrichment step.In certain embodiments, it is desirable to remove divalent ion and silicon-dioxide from the solution of chloride containing lithium.From the salt solution comprising geothermal brine, the method for abstraction and purification lithium chloride is known in the prior art, such as, at US4, and 036,713 and 5,951, state in 843, which is hereby incorporated by reference for these two sections of patents.
Optionally, described method can comprise the step improving lithium chloride stream concentrations.Especially, lithium concentration method (not shown) can be applied and remove a part of water in the solution 30 of chloride containing lithium, such as, be undertaken by evaporation, thus produce more concentrated lithium chloride solution.Exemplary concentration method can comprise electrodialysis, steam raising or solar evaporation.In the embodiment using enrichment step, the total concn of the solution 30 of the chloride containing lithium after concentrated can be increased to the lithium chloride being greater than 25wt%, preferably the lithium chloride of about 42wt% at the most.
The solution 30 of chloride containing lithium can be supplied to electrochemical cell 32, prepare lithium hydroxide for electrochemistry, wherein said electrochemical cell at least can comprise an anode, a negative electrode and permeable membrane.The electrochemical cell being suitable for scale operation can be commercially available by multiple company, such as DeNora, ChlorineEngineers and AsahiGlass etc.Particularly, chlorion is chlorine G&W in anodic oxidation is hydroxide ion and hydrogen in cathodic reduction.In certain embodiments, the solution 30 of the chloride containing lithium after concentrated is substantially free of other ion, and particularly those may disturb the ion of electrochemical reaction.Optionally, under the condition first not standing silicon-dioxide control and lithium ion isolation step, the logistics 30 of chloride containing lithium directly can be supplied to electrochemical reaction, condition is that the solution of chloride containing lithium is substantially free of non-lithium ion, particularly may disturb the non-lithium ion of electrochemical reaction.In certain embodiments, in the solution 30 of chloride containing lithium after concentration, the concentration of sodium and/or potassium ion is less than about 5wt%, is preferably less than about 3wt%.If all existed, the total concn of positively charged ion as iron, calcium, magnesium etc. is preferably less than about 0.001wt%, is more preferably less than about 0.005wt%, and is even more preferably less than about 0.00001wt%.Higher interfering ion concentration can not hinder the operation of electrochemical cell, but may reduce the entire life of battery component and/or the total efficiency of reaction.
Be similar to and above-mentionedly disturb cationic existence about non-lithium, the total concn of the non-cl anion that electrochemical cell 32 preferably contains is less than about 5wt%, is preferably less than about 3wt%, and is even more preferably less than about 1wt%.
The negative electrode of electrochemical cell 32 can be any suitable material, comprises nickel, the nickel screen of catalysis, stainless steel, the stainless steel of coating, soft steel and analogue.Other exemplary catalyst can comprise the ruthenium compound of the mixing with low-hydrogen over-potential, platinum and other similar compound.The total area of negative electrode can regulate based on reactor size and required output.The catholyte raw material of electrochemical cell 32 can for having enough ions with any suitable material of load current.Although can water be used, in certain embodiments, it may be useful for adding Quilonum Retard or lithium hydroxide for the operation of battery.
The anode of electrochemical cell 32 can be any suitable material, as the titanium net applied with ruthenium oxide, the titanium net using platinum and carbon coating or analogue.Anode is preferably the anode of dimensional stabilizing, to allow to reduce watt consumption.The Ni―Ti anode of dimensional stabilizing due to titanium matrix corrosion-resistant and be particularly suitable for chlorine environment.The total area of anode can regulate based on reactor size and required output.The anolyte of electrochemical cell 32 can be any suitable material, and comprising concentration is that about 1wt% is to lithium chloride solution that is saturated, that be preferably 5-40wt%, be more preferably about 10-35wt%.
For construct the material of electrochemical cell 32 can be to chlorine, activation chlorine, containing oxygen chlorine class material and can exist in salt brine solution other dissolve any material that class material chemically tolerating.Structure electrochemical cell 32 exemplary materials comprise tetrafluoroethylene (PTFE), poly(vinylidene fluoride) (PVDF), HALAR (alternating copolymer of ethene and trifluorochloroethylene (CTFE)) and other fluoridize or partially fluorinated thing.
The film of electrochemical cell 32 can for cation selective by and stop any suitable semi-permeable cation selective film that negatively charged ion passes through.This film is known in the prior art.A kind of exemplary film is the material of Nafion (E.I.DuPontdeNemoursCo), particularly Nafion300,400 and 900/9000 series.Other suitable film can be supplied by Flemion, but can use any suitable mould material, as long as described material is chemically tolerating chlorine and lithium hydroxide.Described film can placed by between the anolyte of electrolysis and catholyte.
In certain embodiments, before the solution 30 of chloride containing lithium or salt solution are supplied to the step of electrochemical cell 32, described method optionally can comprise one or more filtration or separated-purified step.
In the operating process of electrochemical cell 32, under the voltage that can lie prostrate at about 1.5-5, apply about 500-10,000A/m
2current density.Preferred applying about 2000-7000A/m
2current density.
Electrochemical cell 32 can operate at the temperature of about 60-100 DEG C, is preferably about 70-95 DEG C, and is more preferably about 90-95 DEG C.Battery 32 can under atmospheric pressure operate, or slightly higher than normal atmosphere.
The operation of electrochemical cell 32 produces lithium hydroxide in the solution, and also releases by product chlorine and hydrogen, and required by product can be removed respectively by pipeline 34 and 35 from electrochemical cell.
The efficiency of electrochemical cell 32 is at least about 60%, is preferably at least about 70%, is more preferably at least about 80%, is more preferably at least about 90%, is more preferably at least about 95%, and is even more preferably at the most about 99.9%.Can electrolysis described in operate continuously until the concentration of lithium hydroxide reaches about 17wt%, now can remove lithium hydroxide solution, and provide it to carbonation reactor.When lithium hydroxide concentration is greater than about 17wt%, the lithium hydroxide in solution may start precipitation.Operate electrochemical cell 32 under the condition that also can be used for producing lower concentration lithium hydroxide solution in design, described lower concentration lithium hydroxide solution can loop back described carbonation reactor and from described carbonation reactor.Electrochemical cell 32 can also comprise for provide to battery water, low-concentration hydrogen Lithium Oxide 98min, lower concentration Quilonum Retard or their combination feed line (not shown).
Lithium hydroxide solution 36 is supplied to carbonation reactor/resorber 38 from electrochemical cell 32, and such as contacts with carbon dioxide gas 44 in the mode upwards flowed.Carbonation reactor/resorber 38 can comprise a series of pallet or other similar facilities, its design is used for allowing lithium hydroxide 36 be supplied to the top of reactor and flow through reactor in the mode flowed downward, thus contact with the carbon dioxide gas 44 upwards flowed, and described carbon dioxide gas can be introduced at the bottom place close to carbonation reactor/resorber 38.In an alternate embodiment, carbonation reactor/resorber 38 can comprise the various mixing facilities that design is used for promoting liquids and gases mixing.Optionally, carbonation reactor/resorber 38 can for having the jacketed type batch reactor of thermostatically heating.Described reaction produces Quilonum Retard solid.The concentration of Quilonum Retard slurries is preferably the Quilonum Retard at least about 1.5wt%, is more preferably the Quilonum Retard at least about 6wt%.Can capturing carbon dioxide loop back carbonation reactor/resorber 38 by pipeline 42.
In certain embodiments, react in water can produce Quilonum Retard by lithium chloride and sodium carbonate, wherein under the condition stirred, described mixture is heated, be preferably heated to the temperature of about 90-95 DEG C.Reaction produces solid carbonic acid lithium and sodium chloride solution, wherein sodium chloride solution can be made to be separated with the Quilonum Retard solid wanted by filtering.
Lithium carbonate solution 40 can be supplied to filtration facility 46, can operate that the slurries 40 of lithium carbonate containing are separated into water logistics 52 and solid carbonic acid lithium product 50 with filtration facility 46, wherein said water logistics 52 can optionally reoffer to described filtration facility.Filtration facility 46 can comprise such as a series of net or strainer and water supply 48.Optionally, water cycle can be made to return described method by pipeline 52.Optionally, Quilonum Retard can be concentrated by centrifugation or decant multiviscosisty from slurries.The water collected in the process of facility 46 separate solid from slurries after filtration can be supplied to electrochemical cell, or can be supplied to geothermal well or reservoir.In certain embodiments, Quilonum Retard solid can be retained on belt filter and to be supplied to washing step, wherein applies hot water, preferable temperature is the hot wash solid of about 90-95 DEG C.In certain embodiments, the aqueous solution collected by filtration facility 46 can have the pH being greater than about 9, and most possible pH is about 10-12.Alternatively, enough acid can be added to reach the pH of about 5-8.5 in the aqueous solution, and acidified water can be supplied to lithium leaching process.Alternatively, described solution can when without in advance and directly return the cathode side of electrolyzer.
Solid carbonic acid lithium 50 is supplied to dryer section 54, and described dryer section optionally can comprise heating installation and provide the pipeline of nitrogen or other rare gas element for described room.Then can collect, pack dry lithium carbonate product 56, and conveying is to apply further.
Below with reference to the accompanying drawings 2, which provide the alternate embodiment of producing Quilonum Retard.Lithium chloride logistics 30 is contacted with sodium carbonate, and wherein said sodium carbonate is by electrochemical production sodium hydroxide and subsequently its carbonating is produced sodium carbonate and prepare.
Sodium-chlor logistics 60 is provided to electrochemical cell 32 as above.Sodium-chlor logistics 60 stands electrolysis, to produce sodium hydroxide logistics 62 and chlorine and hydrogen 64.The reaction conditions being produced sodium hydroxide by electrolytic sodium chloride is known in the prior art.
In certain embodiments, the electrolytic efficiency of sodium-chlor is at least about 70%, is alternatively at least about 80%, is alternatively at least about 90%, or is alternatively at least about 95%.In certain embodiments, sodium hydroxide solution 62 is produced with the concentration at least about 10wt%, is more preferably at least about 30wt%, and most preferably is about 35wt%.
Chlorine and hydrogen 64,65 can burn, and wash with water to produce hydrochloric acid, and described hydrochloric acid can be applied in present method, or alternatively can carry out purifying, compression and business sale.
Lithium hydroxide logistics 62 is supplied to carbonation reactor/resorber 38, and described sodium hydroxide logistics wherein such as contacts with carbon dioxide gas 44 in the mode upwards flowed.Carbonation reactor/resorber 38 can comprise a series of pallet, its design is used for allowing sodium hydroxide logistics 62 be supplied to the top of reactor and flow through reactor in the mode flowed downward, thus contact with the carbon dioxide gas 44 upwards flowed, and described carbon dioxide gas can be introduced at the bottom place close to reactor, thus produce sodium carbonate solution or slurries 66.In an alternate embodiment, carbonation reactor/resorber 38 can comprise the various mixing facilities that design is used for promoting liquids and gases mixing.The concentration of described solution is preferably the sodium carbonate of at least 15wt%, is more preferably the sodium carbonate of at least 25wt%.Can capturing carbon dioxide loop back carbonation reactor/resorber 38 by pipeline 42.
Sodium carbonate solution 66 is supplied to reactor 68, and wherein said solution contacts to produce slurries 70 with lithium chloride solution 30, and described slurries comprise Quilonum Retard and sodium chloride solution.The step making sodium carbonate solution 66 contact with lithium chloride solution 30 in reaction vessel can be implemented at temperature is greater than about 60 DEG C, is preferably greater than about 80 DEG C, and is even more preferably about 90-95 DEG C.In certain embodiments, reaction vessel 68 can be stirred-tank reactor.Alternatively, reaction vessel 68 can be the crystallizer of standard.Sodium carbonate solution 66 can cause Quilonum Retard to produce as settling with the contact of lithium chloride solution 30 under these conditions, and sodium-chlor retains in aqueous.
The slurries 70 comprising solid carbonic acid lithium and moisture sodium-chlor are supplied to separator 72, to produce lithium carbonate product logistics 74 and the sodium chloride salt aqueous solution 76, wherein said separator can comprise the various facilities for separate solid and liquid, such as, comprise whizzer, clarifying tank, strainer, net and analogue.In order to obtain the quality product improved, can by wash with water (be preferably hot water) or by similar method process Quilonum Retard to remove the sodium, potassium and/or the chlorion that retain in the sedimental gap of Quilonum Retard.In certain embodiments, separator facility 72 can be belt filter or rotary drum, and can be used for removing remaining sodium-chlor optionally through countercurrent washing system feeding.Separator facility 72 can also comprise the water-in 73 for washing be separated solid carbonic acid lithium and export 76.Separator facility 72 can also comprise for drying and/or the every facility removing water from solid carbonic acid lithium, such as, comprise whizzer, well heater, gas blower, extrusion machine and analogue.Separator facility 72 can comprise the vacuum filter for removing water.In certain embodiments, it is desirable to optimize described washing step, to maximize the purity of Quilonum Retard, reduce the water yield of washing application simultaneously.Sodium chloride solution 76 can loop back electrochemical cell 32 for electrolysis by pipeline 77.Lithium carbonate product 74 can have the moisture content being less than about 5wt%, is preferably less than about 2wt%, and is even more preferably and is less than about 0.5wt%.
Salt brine solution 76 from separator facility 72 can comprise sodium-chlor and Quilonum Retard.The water yield depending in method and apply in washing process, the ratio of sodium-chlor and Quilonum Retard is generally at least about 20:1, is more preferably at least about 25:1, and is even more preferably at least 30:1.In certain embodiments, in salt brine solution, the ratio of sodium-chlor and Quilonum Retard can be about 35:1.
In certain embodiments, by hcl acidifying salt brine solution 76 (not shown) to the pH being less than about 4, about 3 can be preferably, and loop back electrochemical cell 32.Hydrochloric acid can be provided by electrochemical cell 32.
The Quilonum Retard production method proposed in fig. 3 is favourable, because described method is got rid of or almost eliminated the production of waste prods.Particularly, in certain embodiments, circulation not have the metal-salt of application as sodium-chlor and carbonic acid gas, can make overall yield quantitatively or almost quantitative.
Below with reference to the accompanying drawings 3, which provide another alternate embodiment of producing Quilonum Retard.Described method is an one-step method, wherein produces sodium carbonate and react with the lithium chloride reclaimed, but may need the input that adds and produce lithium chloride logistics of giving up, and described useless lithium chloride logistics may comprise the Quilonum Retard be entrained on a small quantity wherein.
There is provided sodium hydroxide solution as described above and shown in accompanying drawing 2.Sodium-chlor logistics 60 is provided to electrochemical cell 32.Sodium-chlor logistics 60 stands electrolysis, to produce sodium hydroxide logistics 62 and chlorine and hydrogen 64,65.
Sodium hydroxide logistics 62 is supplied to mixing tank 80, and wherein sodium hydroxide logistics combines with lithium chloride logistics 30 and mixes.The mixing of sodium hydroxide logistics 62 and lithium chloride logistics 30 such as can be undertaken by agitator or mixing tank, using ultrasound ripple or similar approach by currently known methods.Mixing tank 80 production mixture flow 82, it comprises sodium hydroxide in aqueous and lithium chloride.In certain embodiments, the concentration of preferably lithium chloride logistics 30 may be at least about 20wt%, be more preferably at least about 28wt%, and be even more preferably at least about 42wt%.Similarly, in certain embodiments, the concentration of preferably sodium hydroxide logistics 62 may be at least about 15wt%, be more preferably at least about 25wt%, and be even more preferably at least about 35wt%.
Mixture flow 82 is supplied to the carbonation reactor/resorber 84 that can comprise a series of pallet, described tray design is used for allowing the mixture flow comprising lithium chloride and sodium hydroxide be supplied to the top of reactor and flow through reactor in the mode flowed downward, thus allow described mixture flow fully to contact with the carbon dioxide gas 44 upwards flowed, and described carbon dioxide gas can be introduced by pipeline 22 at the bottom place close to reactor, thus produce Quilonum Retard slurries 90.Carbonation reactor/resorber 84 preferably remains the temperature of about 90-100 DEG C.In an alternate embodiment, reactor 84 can comprise the various mixing facilities that design is used for promoting liquids and gases mixing.The concentration of Quilonum Retard is preferably at least 15wt%, is more preferably the Quilonum Retard of at least 25wt%.By pipeline 42, carbon dioxide recycle can be returned carbonation reactor 84.
Lithium carbonate solution 90 can be supplied to separation vessel 92, wherein produce solid carbonic acid lithium by pipeline 94.The solution comprising sodium-chlor and possible a small amount of Quilonum Retard is produced as logistics 96.
The sodium carbonate solution 90 comprising solid carbonic acid lithium and moisture sodium-chlor is supplied to separator facility 92, and wherein said separator can comprise the various facilities for separate solid and liquid, such as, comprise whizzer, clarifying tank, strainer, net and analogue.Separator facility 92 can also comprise the water-in 93 for washing be separated solid carbonic acid lithium and export (not shown).Separator facility 92 can also comprise for drying and/or the every facility removing water from solid carbonic acid lithium, such as, comprise whizzer, well heater, gas blower, extrusion machine and analogue.Solid sodium carbonate product is collected by pipeline 94.Optionally, by pipeline 97, partial oxidation sodium logistics 96 can be looped back electrochemical cell 32.Optionally, described sodium chloride solution can be looped back the washing step of lithium Extraction medium.In certain embodiments, the sodium-chlor of process need can be produced by selective crystallization sodium-chlor from underground heat, Smackover or other salt solution.
In certain embodiments, the facility of any Quilonum Retard comprised during described method can comprise and in sodium chloride solution, such as, by adding in the hydrochloric acid of significant quantity or class acidoid and described solution.Can by the embodiment of effective elimination at Quilonum Retard, chemical cell of solution circulated can being wired back, but any Quilonum Retard comprised wherein all can cause electrochemical cell performance problem.
Embodiment
Embodiment 1
The carbonating of sodium hydroxide
Apply the carbonating of 3 liters of jacketed reactors (being manufactured by SyrrisReactorSystems, UK) the enforcement sodium hydroxide with heating system.The sodium hydroxide solution (27.5% solid) that 1 liter of 9.5M is applied in described reaction at the temperature of about 95 DEG C is implemented.Carbonic acid gas with the speed of 3L/min provide about 1 hour (about 8 moles altogether, about 1.7 molar equivalents) to guarantee that sodium hydroxide transforms completely.At the end of sodium hydroxide solution carbonating, obtain the clear solution of sodium carbonate, stop carbonation reaction at this some place, and continuous heating sodium carbonate solution several minutes.Before reacting with lithium chloride solution (the 404g lithium chloride in 1000mL), in described clear solution, add Quilonum Retard crystal seed.The productive rate of test is 95%.For the reaction that other is similar, productive rate depends on test conditions and changes, and sometimes at the most about 100%.Before washing, the purity of the Quilonum Retard of separation is about 96.6%.
Before first time cleaning product logistics, Quilonum Retard is containing, for example lower impurity: Na (71mg/kg), Ca (2.8mg/kg), Mg (2.1mg/kg), Fe (0.3mg/kg), Ba (0.1mg/kg), Mn (0.08mg/kg) and Sr (0.03mg/kg), and purity is about 78.4%.After water washing with about 2-3 volume, described na concn is reduced to undetectable level, with described Quilonum Retard containing, for example lower impurity: Mg (5.9mg/kg), Ca (2.9mg/kg), Ba (0.4mg/kg), Fe (0.4mg/kg), Mn (0.07mg/kg) and Sr (0.07mg/kg), purity is greater than 99%.
Wash conditions affects the amount of the sodium carbonate/sodium-chlor carried secretly in lithium carbonate product.
Embodiment 2
Concentrated LiCl solution transforms after purifying is concentrated LiOH solution by electrolytic process, for being converted into lithium bicarbonate subsequently.Because hydroxide radical is through the reverse migration of film, determine that the limiting factor of electrochemical cell efficiency is the concentration of lithium hydroxide in catholyte.Therefore, contrived experiment scheme to operate electrochemical cell under four different hydroxide radical concentration, thus determines the peak concentration that the impact determining of lithium hydroxide concentration may be prepared.Contrived experiment is using the current efficiency of the function measurement dialysis process as hydroxide radical concentration and Energy harvesting.In electrochemical cell, the Li when applied field
+ion migrates to catholyte from anolyte, and existing water is H at catholyte
2and OH
-.In theory, each electronics carried in external circuit corresponds to the increase of a LiOH molecule in catholyte, causes the concentration of LiOH to increase in time.Main inefficiency in the method and OH
-the OH that anolyte depends on catholyte is oppositely migrated to from catholyte
-concentration.Therefore, by adding the OH that water makes catholyte with known mass flow
-concentration implements the experiment reported here under keeping constant object.By comparing the actual flow that adds water and theory adds flow measurement reaction efficiency.
Embodiment 3: by lithium chloride electrolysis production lithium hydroxide.
Testing installation.
Described electrolytic system is made up of the electrolyzer with anolyte and catholyte flow system.The electrolysis of LiCl solution is applied the FM01 electrolyzer sealed model of the FM21 electrolyzer of commercial applications (in the chlorine industry) manufactured by ICI and is implemented.Electrolyzer comprises lantern paddle electrode (anode: the titanium of ruthenium oxide coating; And negative electrode: nickel) and
982 films.The active surface area of each electrode is about 64cm
2(4 × 16cm), and battery interval (anode is to the measuring distance of negative electrode) is about 12-13mm.The FM01 electrolyzer flow direction parallel with 16cm direction operates (as plan operates, comparing with the flow direction of 4cm dimension parallel), because which improve the control to the chlorine of discharging from electrode and hydrogen.In addition, although anolyte and catholyte stream are usually from the opposite side charging of battery, in this test, anolyte and catholyte are from the same side charging of electrochemical cell.
Anolyte flow system comprises charging stock tank, pump, degassing vessel, chlorine washer and holding tank.Be that the lithium chloride solution of about 21wt% is put into anolyte charging stock tank and is heated to about 90 DEG C by concentration.Solution through heating is pressed single circulation pattern with about 20cm
3the flow (corresponding to the surface velocity of about 0.13cm/s) of/min is pumped into the anolyte compartment of battery.When flowing out battery, lithium chloride solution and the chlorine (producing at anode) carried secretly flow through and are equipped with the degassing vessel of chlorine washer to remove chlorine.Then described lithium chloride solution is pumped into holding tank to be used for storing.
Catholyte flow system comprises charging stock tank, pump and water feed system.Lithium hydroxide put into charging stock tank and is heated to about 95 DEG C, and being fed in the cathode compartment of electrochemical cell with the flow of about 50mL/min (being equivalent to the surface velocity of 0.33cm/s) by recirculation mode.Application peristaltic pump adds water, continuously to keep constant lithium hydroxide concentration in system.Monitored by the weight loss of water pot and add inbound traffics.Nitrogen bubble passes through catholyte circulation tank to reduce the carbon dioxide reaction in lithium hydroxide and air.
Table 1 summarizes in test for determining the test conditions of catholyte concentration effect.
Table 1: the experiment parameter of electrolytic experiment.
Parameter |
Numerical value |
Current density |
3000A/m
2 |
Electrode area |
64cm
2 |
Anolyte volume |
60cm
3 |
Catholyte volume |
60cm
3 |
LiCl temperature in |
21wt% |
LiCl entrance pH |
0.5-0.7 |
Temperature |
90℃ |
Operating time |
2-3 hour |
Anolyte (LiCl) flow velocity |
0.13cm/s |
Catholyte (LiOH) flow velocity |
0.33cm/s |
In electrochemical cell operating process, collected a sample at catholyte entrance and exit and anolyte outlet every 30 minutes.Apply hand-held volt ohm-milliammeter at battery terminal place monitoring cell voltage.The catholyte hydroxide radical concentration difference of application entrance and exit and cell voltage calculate efficiency and the energy expenditure of battery.
Result
The result of catholyte concentration is summed up in table 2 and provides in figures 4-7.Accompanying drawing 4 to confirm under the condition not measuring hydroxide radical concentration in real time and only adds based on what regulate water the difficulty that inbound traffics keep constant LiOH concentration, this is because water or can be added in catholyte by various mechanism consumption, comprises electrolysis, evaporation and and Li
+positively charged ion migrates across film together.In a word, data show that the initial concentration of LiOH is higher, keep the more difficult realization of task of constant concentration by adding water.
For all test runs, described cell voltage all remains about 4.3-4.4V.Accompanying drawing 5 shows that cell voltage is relatively independent of hydroxide radical concentration, this means that energy expenditure is decided by the electrical efficiency of electrode and film reaction to a great extent.The battery interval (12-13mm) of the FM01 electrolyzer applied in this experiment is very large compared with the battery interval (2-3mm) usually applied in commercial battery, therefore expects that commercial battery has the cell voltage lower than the value measured here.
Accompanying drawing 6 shows that current efficiency increases with lithium hydroxide concentration and reduces.Not wish limit to by any one theory, believing that this current efficiency reduces may be due to when lithium hydroxide concentration increases, and hydroxide radical anion oppositely migrates across film increase from catholyte to anolyte.As shown in Figure 7, this also causes energy expenditure to increase, because all experiments are all implemented under identical current density, and cell voltage keeps constant substantially.Experiment shows that the preferred concentration of lithium hydroxide in an electrochemical cell may be about 1-2M.
Table 2 summarizes test-results.As illustrated, when lithium hydroxide concentration reduces, the production efficiency of lithium hydroxide increases, and when the concentration of lithium hydroxide solution is about 1M (2.4wt%), efficiency is about 80-88% at the most.Cell voltage is relatively independent of the concentration of lithium hydroxide, and therefore efficiency also determines energy requirement, under concentration is about 1M, produces 1kg lithium hydroxide energy requirement and is reduced to about 5kWh.During lower lithium hydroxide initial concentration, the throughput rate of lithium hydroxide is maximum.
The general introduction of table 2. result.
* calculated value (throughput rate=2.68kgLiOH/m
2/ hr × efficiency).
Embodiment 4: carbonating.
Chemical reactor.Application has induction pH, temperature, reagent adds makes lithium hydroxide carbonating with 3LSyrris automatic batch-type reactor assembly (SyrrisLtd27JarmanWay, UK) of the control of sample extraction.Electrolysis research detailed above shows that the electrolysis of lithium chloride can produce the lithium hydroxide solution of 1M or 2.4wt% at the most.Really, have been found that this concentration is desirable for the research of enforcement carbonating, under our experiment condition, do not have blockage problem to occur.
Carbonation kinetics.Carry out in process in reaction, determined the carbonation kinetics of lithium hydroxide by the pH and concentration of metal ions (application atomic absorption) monitoring solution.About 84.0g Lithium hydroxide monohydrate is dissolved, to prepare the solution of concentration for about 1M (about 2.4wt%) in 2000mL water.The water-ethylene glycol mixture reactor heating chuck of application 30:70, and make the temperature of lithium hydroxide solution remain about 95 DEG C.With mechanical stirrer solution described in Keep agitation under 250RPM in carbonation.Carbonic acid tracheae remains on the depth of at least 6cm in alkaline solution, starts inflation, and application traffic meter (MathesonTri-Gas, USA) gas-monitoring flow continuously.Carry out in process in carbonating, the pH of solution increases a little, and determines that reaction completes by the sharply reduction of pH value of solution, stops carbonic acid gas flowing into reactor subsequently.The reduction of pH is consistent with the formation of lithium bicarbonate, and lithium bicarbonate is at high temperature unstable.Therefore, continue solution described in heated/stirred, form Quilonum Retard to decompose lithium bicarbonate.The decomposition of lithium bicarbonate causes pH to increase, and pH stablizes in time gradually.In reaction process, monitor lithium concentration, and show that the excessive carbonating of solution may cause the formation of supercarbonate.
In the process of carbonating, in lithium hydroxide solution, add the carbonic acid gas of molar excess a little, to compensate the poor mixing of carbonic acid gas in lithium hydroxide solution.After carbonation reaction completes, to described solution heat filtering, this is because at high temperature the solubleness of Quilonum Retard in water reduces.The first drying about 18 hours at about 60 DEG C of solid after filtration, then drying about 24 hours at about 120 DEG C, thus guarantee that any remaining lithium bicarbonate that may exist in solids is converted into Quilonum Retard.Under slightly different test conditions, and to utilize and under condition without Quilonum Retard crystal seed, with 1 molar lithium hydroxide solution weight carbon restoration acidification reaction repeatedly.Result provides in following table 3.Productive rate can be improved as lithium hydroxide solution crystal seed with Quilonum Retard crystal.Under higher carbon dioxide flow (such as 3L/min and larger), the productive rate of described carbonation reaction is still very high.Just as shown in table 3, although the total amount of the carbonic acid gas added changes between about 1.25-2.5 mole (i.e. about 0.625-1.25 molar equivalent), the charging of carbonic acid gas remains about 2L/min.Experiment 1 in table 3 comprises and add nitrogen in carbonating container.Experiment 3-5 in table 3 comprises the lithium hydroxide crystal seed adding about 0.6-1.2wt%.Described result shows that increasing speed of reaction can allow to reduce reactor size, and reduces associated total cost.
The carbonation reaction of the LiOH solution of table 3:2.4wt%
by mixing 84g lithium hydroxide (LiOHH in 2L water
2o) prepare.
# total recovery comprises the amount of the Quilonum Retard/lithium bicarbonate dissolving in the solution and deposit in reactor wall.
* excess carbon acidifying and not by LiHCO
3transform back Li
2cO
3condition under filter.
Method as described herein is suitable for reclaiming lithium by having in the salt solution of low and high lithium concentration or solution, and described salt solution or solution also comprise other ion of obvious concentration in addition, comprise polyvalent ion.
As what understand in prior art, not every equipment or device provide all in the drawings.Such as, those skilled in the art will recognize that and can use various basin and/or pump in the method.
If do not explicitly not pointed out in context, then singulative comprises plural number.
Optionally or optionally refer to that the event that describes subsequently or situation may occur also may not occur.And the situation of described description when comprising situation when event or situation occur and do not occur.
Scope here can be expressed as from an about particular value and/or to another particular value about.When such a range is expressed, be understood that another embodiment is from a particular value and/or to another particular value, and all combinations in described scope.
In this application, with reference to patent and publication, whole disclosures of these reference are in this application as with reference to introducing, and object is the state more fully describing prior art belonging to the present invention, unless these reference and content as described herein contradictory.
As used herein, quote relative to numerical range the upper and lower bound that term " about " and " approximately " should be interpreted as comprising described scope.
Although describe the present invention in detail, to it should be understood that under the condition not departing from principle of the present invention and scope and can carry out various change to it, substitute and change.Therefore, scope of the present invention should be required to determine with their suitable legal equivalents by following patent.