Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
  • B01D61/027—Nanofiltration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/42—Electrodialysis; Electro-osmosis ; Electro-ultrafiltration; Membrane capacitive deionization
  • B01D61/44—Ion-selective electrodialysis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/58—Multistep processes
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
  • C01D15/00—Lithium compounds
  • C01D15/02—Oxides; Hydroxides
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B1/00—Electrolytic production of inorganic compounds or non-metals
  • C25B1/01—Products
  • C25B1/14—Alkali metal compounds
  • C25B1/16—Hydroxides
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/54—Reclaiming serviceable parts of waste accumulators
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/52—Reclaiming serviceable parts of waste cells or batteries, e.g. recycling
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/14—Cells with non-aqueous electrolyte
  • H01M6/16—Cells with non-aqueous electrolyte with organic electrolyte
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/84—Recycling of batteries or fuel cells

Definitions

• This invention relates to a method and apparatus for the recovery and/or purification of lithium from, in particular, although not necessarily solely, crushed, alkali hydrolysed primary and secondary lithium battery waste.
• the principles can be applied to any water soluble lithium sources.
• a single-pass electrolytic process effectively generates lithium hydroxide by splitting the lithium salt and water fed to the unit.
• the salt and water splitting steps require significant energy. Consequently, double-pass or multipass electrodialysis is not a good way to further purify lithium hydroxide in terms of energy consumption.
• Nanofiltration is also a technique which can be performed repeatedly to obtain desired solution purities.
• the feed solutions are generally acidic or very slightly alkaline.
• lithium hydroxide is highly alkaline.
• a typical feed solution of lithium hydroxide may have a pH of 1 4 or greater.
• the nanofiltration membranes utilised in such prior art apparatus are generally unable to process lithium hydroxide solutions due to the instability of the membrane at such high pH levels.
• the invention may broadly be said to consist in a method for the recovery and purification of lithium from lithium battery waste including:
• the anolyte may have a pH greater than 7.
• the anolyte and catholyte may be circulated through their respective anode and cathode compartments.
• the method may further include the step of keeping separate any gases produced at the anode and cathode.
• the method may include further purification of the lithium hydroxide solution by nanofiltration, including the steps of: - providing a nanofiltration membrane having stability at a pH of at least 1 1 ;
• the invention may broadly be said to consist in a method for the purification of monovalent lithium salt solutions comprising the steps of:
• nanofiltration membrane having stability at a pH of at least 1 1 ;
• the feed stock solution may have a temperature of substantially greater than or equal to 5 °C.
• the feed stock may be provided at a pressure of greater than 5 Bar, and more preferably greater than 1 5 Bar.
• the invention may broadly be said to consist in an apparatus for the recovery of lithium from lithium battery waste including:
• the cation exchange membrane may comprise a Nafion 350 membrane.
• the invention may broadly be said to consist in an apparatus for the purification of monovalent lithium salt solutions including:
• nanofiltration membrane within said filtration unit having a stability at pH levels of at least 1 1 ;
• the nanofiltration membrane is stable at a pH of at least 1 4. Further aspects of the invention may become apparent to those skilled in the art to which the invention relates upon reading the following description.
• the invention involves two parts.
• the first part principally relates to a method and apparatus for the production of substantially pure lithium hydroxide from primary and secondary lithium battery waste.
• the lithium hydroxide thus obtained can be further purified using the second part of the invention, or can be converted into different high purity lithium salts, including lithium carbonate for the manufacture of lithium battery materials.
• the second part of the invention relates to the purification of lithium hydroxide solution by nanofiltration, whilst the first process involves the use of an electrolytic cell.
• the general arrangement can be seen to include an electrolytic cell 1 having a membrane 2 which will allow the passage of lithium ions but generally keep the liquid and gas in the anode and cathode compartments separate from one another.
• a power source 3 is provided to pass a current from the anode 4 to the cathode 5 through the anolyte and catholyte 6 and 7; respectively.
• the membrane 2 Due to the reaction taking place within the electrolytic cell, lithium ions migrate from the anode compartment, through the cation exchange membrane 2, to the cathode compartment. It should be noted that the membrane 2 also serves to separate any gases which are produced at either electrode. The membrane also prevents the back migration of the hydroxy ions from the catholyte as well as the diffusion of contaminating anions into the catholyte from the anolyte. The membrane 2 can achieve this through the selective choice of membrane having a suitable porosity for the passage of lithium while reducing the ability of other cations to diffuse through the membrane. Additionally the membrane holds a negative charge which discourages the passage of anions.
• the lithium containing battery waste may be processed into a slurry and then filtered in a solid/liquid filter 14. This is then followed by a washing step in a solids washing apparatus 1 5 to recover further lithium bound up in the material. This results in a filtered soluble mixed lithium salt containing battery waste.
• this solution would have a pH in the range 1 1 .5 to 1 2. The efficiency of the process is dependent on the starting pH of the solution, the higher the pH the more efficient the process. A pH of 7 or more is preferred.
• the filtered soluble mixed lithium salt containing battery waste solution can be supplied as the anolyte in the cell and is pumped through the anode compartment by a pump 8.
• a substantially pure lithium hydroxide solution is circulated under the influence of a pump 9.
• Separate chambers 10 and 1 1 may be provided interconnected with the anode and cathode compartments respectively.
• the apparatus can also provide collection of the hydrogen gas produced as part of the electrolytic process and this may be collected in gas collector 1 2. If desired the hydrogen gas may be utilised in power generation to provide some further efficiencies on the apparatus as a whole.
• the flow velocity may also need to be considered.
• the flow velocity may also enhance mixing, convection and the removal of gaseous products to overall reduce the resistance of the solution and enhance lithium extraction.
• a matter specific to battery waste solutions is the presence of the sulphur oxyanions. Their oxidation at the anode will reduce the initial electrolysis voltage required and will prevent the production of oxygen. As the extraction process proceeds, the sulphur oxyanions will be consumed resulting in the consumption of hydroxide ions and water molecules. Both effects result in the production of oxygen and the reduction of anolyte pH. Furthermore, chloride present in the anolyte will be oxidized to chlorine during the process. On complete transfer of lithium from the anolyte to the catholyte, the residual anolyte will consist largely of concentrated sulphuric acid.
• a battery waste solution was filtered to separate the insoluble battery waste materials. This yielded 2.3L filtrate with a lithium concentration of 2% .
• the electrolytic cell was assembled with the Nafion 350 membrane. Filtered soluble mixed lithium salt containing battery waste solution with an initial lithium concentration of 2% was circulated in the anode compartment, whereas lithium hydroxide solution of substantially lower lithium concentration was circulated in the cathode compartment to reduce the overall cell resistance. Flow rate optimization was performed by monitoring the cell voltage at different anolyte and catholyte flow rates.
• Water migration could also be calculated by measuring the volume change of catholyte.
• the cell characteristics of the trial were obtained using a Nafion 350 membrane and a current density of 2kA/m2.
• the cell voltage was 5.3 volts with a current efficiency ranging from 91 -74%.
• the energy consumption ranged from 39-34 gLi/kWhr.
• the cathode gas, hydrogen, production rate was around 1 200 L/m ⁇ /hr and approached 100% current efficiency. There was not much gas emission at the anode during the first 50% lithium transfer due to the preferential oxidation of sulphur oxyanions at the anode.
• the anode gas emission, essentially oxygen, reached a maximum of about 550 L/m ⁇ /hr at 70% lithium transfer.
• Composition of the feed and products at 90% lithium transfer Composition of the feed and products at 90% lithium transfer.
• the lithium hydroxide was carbonated using food grade carbon dioxide without product washing.
• the assay of the lithium carbonate obtained was 99.3%.
• the purity can be further increased by washing the product with deionized water but the product yield will be lower.
• the trace impurities in the lithium hydroxide can be removed through the use of ion exchange resins.
• the usable resin bed volume before column breakthrough is not economical and a large amount of chemical waste will be generated during resin regeneration. Consequently, the second part of the invention involves the purification of lithium hydroxide solution using a nanofiltration membrane.
• the nanofiltration technique is simple, offers high lithium recovery and high rejection for divalent and multivending ions, and does not generate large amount of chemical waste.
• Nanofiltration membranes are generally, although not necessarily always, multiple layer thin film composites of polymers.
• the active membrane layer often consists of negatively charged chemical groups and are believed to be porous with an average pore diameter of 2 nanometers.
• nanofiltration membranes will retain large molecules and certain multivending salts such as MgS ⁇ 4 but pass substantial amounts of most monovalent salts and monovalent metal hydroxides.
• a monovalent lithium salt or lithium hydroxide can be purified using nanofiltration membranes to reject divalent ions.
• the filter 21 and membrane 22 may be used in an overall apparatus to provide nanofiltration in batch mode. Alternatively, other configurations could allow continuous processing.
• a feed solution of lithium hydroxide is provided in the container 23.
• the solution 24 may pass through a conduit or similar 25 and through a pump 26 to increase the pressure of the solution as it enters the filtration module 21 .
• pressure is an important component of the separation and the pressure is preferably greater than 10 Bar and, more preferably, approximately 20 Bar, although pressure as high as 40 Bar may be used.
• the solution passes over the membrane 22 towards the outlet 27, the solution is separated into a permeate and a retentate.
• the retentate may be passed through a conduit 28 to the container 23 and is preferably, though not necessarily, passed through a pressure valve 29 so that the pressure may be released.
• the permeate 30 may be drawn off through a separate outlet 31 on an opposed side of the membrane 22 from the inlet 32.
• the retentate can be passed through the filtration unit 21 again until a sufficient concentration factor is obtained.
• the process was continued until a concentration factor being the ratio of the feed volume against the retentate volume had reached approximately 9.
• the temperature may be monitored and controlled by a sensor and/or heating means 33. Although shown in the container 23, the heating of the feed solution can be provided at any suitable point prior to entering the filtration unit 21 .
• the permeate rate rose to a maximum of approximately 1 2 L/m ⁇ /hr and again dropped back as with the previous trial. It was noticed that lower lithium hydroxide concentrations have higher permeate rates.
• the limiting concentrations for lithium hydroxide were found to be 1 1 % which is very similar to its aqueous solubility at room temperature. In consideration of temperature, it was found that the permeate rates were increased by 2-3% per degree Celsius rise in temperature.
• a suitable membrane is a Koch nanofiltration membrane.
• a membrane supplied by Koch such as the MPS-34 nanofiltration membrane is stable at the necessary pH conditions and provides operating conditions including the maximum pressure of 35 bar at 40°C or a maximum temperature of 70°C at 1 5 bar. Such a membrane would appear suitable for the purification of lithiums and monovalent salt solutions.
• the second part of the invention provides the process for the purification of lithium hydroxide and monovalent salts which utilises pressure for the separation. Furthermore, this selection of the membrane allows this process to be provided at suitable pH ranges for lithium hydroxide.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Water Supply & Treatment (AREA)
• Organic Chemistry (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• General Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Inorganic Chemistry (AREA)
• Nanotechnology (AREA)
• Sustainable Development (AREA)
• Life Sciences & Earth Sciences (AREA)
• Urology & Nephrology (AREA)
• Health & Medical Sciences (AREA)
• Metallurgy (AREA)
• Separation Using Semi-Permeable Membranes (AREA)
• Water Treatment By Electricity Or Magnetism (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
• Secondary Cells (AREA)

Applications Claiming Priority (5)

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• 1998
  • 1998-06-18 JP JP50423599A patent/JP2001508925A/ja not_active Ceased
  • 1998-06-18 EP EP98932642A patent/EP1016152A1/de not_active Withdrawn
  • 1998-06-18 AU AU82471/98A patent/AU8247198A/en not_active Abandoned
  • 1998-06-18 WO PCT/NZ1998/000087 patent/WO1998059385A1/en not_active Ceased

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