Process of preparation of nickel, manganese and / or cobalt hydroxides
The described process addresses inefficiencies in preparing nickel, manganese, and cobalt compounds by integrating pre-leaching and selective leaching with precipitation to achieve high-purity compounds with reduced waste and chemical use, optimizing the production of battery materials.
Patent Information
- Application Number
- PCT/EP2025/070012
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-07-11
- Filing Date
- 2025-07-11
- Publication Date
- 2026-01-15
AI Technical Summary
Existing industrial processes for preparing nickel, manganese, and cobalt compounds in lithium-ion batteries are resource-intensive, costly, and generate significant waste, requiring multiple steps and high chemical usage.
A process involving pre-leaching, selective leaching, and precipitation to produce high-purity nickel, manganese, and cobalt hydroxides from a feed material containing these metals and impurities, minimizing chemical use and waste by maintaining the metals together throughout the process.
The process achieves high-purity nickel, manganese, and cobalt compounds with reduced chemical consumption and waste generation, while maintaining the metal ratios and avoiding separation losses, enabling efficient production of battery precursors.
Smart Images
Figure EP2025070012_15012026_PF_FP_ABST
Abstract
Description
[0001] DESCRIPTION
[0002] TITLE: Process of preparation of nickel, manganese and / or cobalt hydroxides
[0003] FIELD OF THE INVENTION
[0004] The invention relates to a process of preparation of a mixture comprising nickel and at least one valuable metal chosen among manganese and cobalt hydroxides from an initial feed material comprising undesired metals and / or impurities in addition of the at least one valuable metal.
[0005] STATE OF THE ART
[0006] Lithium-ion batteries are used worldwide in many devices such as electronics, wireless devices, handheld power tools, electric vehicles such as electric cars, scooters and bikes, and the like. The increasing use of these devices and vehicles renders the fabrication of battery a crucial challenge.
[0007] Some lithium-ion batteries commonly comprise a combination of nickel, manganese and cobalt called NMC materials. The ratio of these three metals may vary depending on the battery type. A common method to prepare such batteries is to use pure nickel, manganese and / or cobalt compounds.
[0008] Preparation of pure nickel, manganese and / or cobalt compounds usually involve industrial processes using as feed material a mixture comprising at least one of nickel, manganese and cobalt compounds, and also impurities that have to be removed. The feed materials that can be used may come for example from natural mines or from recycling materials from the lithium-ion battery chain (for example unqualified CAM, pCAM or black mass, CAM being defined as cathode active material).
[0009] However, such industrial processes may use high quantity of chemicals and / or generate waste difficult to recycle. Further, these processes may involve a high number of steps and may be expensive and time and energy consuming.
[0010] Therefore, there is still a need to improve the industrial processes of preparation of nickel, manganese and / or cobalt compounds.
[0011] DISCLOSURE OF THE INVENTION
[0012] An aim of the invention is therefore to provide a process allowing to prepare high purity nickel, manganese and / or cobalt compounds by limiting the use of chemicals, the waste disposal and / or the number of steps. To this end, an object of the invention is a process of preparation of a mixture comprising at least two valuable metal compounds, said two valuable metals compounds being a nickel complex, and a cobalt and / or a manganese complex(es), from a feed material comprising said at least two valuable metal compounds and at least one undesired metal compound(s), the amount of valuable metals being at least 30% by weight over the total weight of the feed material, the process comprising the steps of:
[0013] - E0 : performing a pre-leaching of the feed material at a pH having a value ranging from 6 to 8 to obtain a pulp, followed by a filtration to obtain a wet solid and a filtrate ;
[0014] - E1 : performing a leaching on the wet solid to transform the at least two valuable metal compounds and the at least one undesired metal compound(s) of the wet solid to the corresponding chloride complexes in an aqueous solution such as the residual acidity is comprised between 0,02 and 1 mol / L of acidic protons (H+);
[0015] - E2: separating selectively the at least one undesired metal complexe(s) from the at least two valuable metal complexes to obtain an intermediate solution free from undesired metals complexes;
[0016] - E3: adding a base chosen among sodium hydroxide, sodium carbonate, and sodium bicarbonate, to the intermediate solution to precipitate the at least two valuable metals under the form of the corresponding hydroxide, carbonate or bicarbonate compounds in a final pulp; and
[0017] - E4: filtering the final pulp to obtain a powder of the at least two valuable metal hydroxides, carbonate or bicarbonate and a solution of sodium chloride, the powder comprising at least 45% by weight of the valuable metals over the total weight of the pulp.
[0018] This process allows to prepare a mixture comprising nickel, and manganese and / or cobalt complexes with an optimized purity, using a feed material, usually solid, containing nickel, and cobalt and / or manganese compound(s), without separating one of these valuable metals from the others during the process.
[0019] Further, the formation at step E1 of metal chloride complexes and subsequent precipitation of the metal complexes using a base comprising sodium allows to obtain a solution of sodium chloride which is a non-toxic and easy to recycle salt.
[0020] Feed material
[0021] The feed material is an impure intermediate metal complexes mixtures that may come from natural mines extractions or from recycling processes, in particular recycling of batteries. The feed material comprises at least nickel compound, and manganese and / or cobalt compound (s), usually under the form of hydroxides.
[0022] Nickel, and cobalt and / or manganese are valuables metals purified together by the process and retrieved together as a powder in step E4. The amount of valuable metals in the feed material is at least 30% by weight over the total weight of the feed material, said amount by determined preferably on a dry basis corresponding to standard NF.EN 14774-1 .
[0023] Further, the ratio of the two or three valuable metal compounds in the feed material may be maintained during the process as nickel, manganese and cobalt are not separated during the process and none of the compounds is lost during the process. This means that the amount of nickel, and manganese and / or cobalt which may be lost at the end of each step of the process may be less than 5% by weight relative to the weight of the corresponding compounds at the beginning of each step.
[0024] In the feed material, nickel, and manganese and / or cobalt are each under their oxidized form or under their metallic form, i.e. nickel(O), manganese(O) and cobalt(O). In the oxidized form, the metal, i.e. nickel, and manganese and / or cobalt, is the central cation and is surrounded by ligands, the ligand being chosen among a neutral molecule, an ion, and a mixture thereof.
[0025] In the present description when nickel, manganese and cobalt are solid, that are under their oxidized form or under the metallic form, they are called “metal compounds”, “nickel compound”, “manganese compound” and “cobalt compound”. Further, when nickel, manganese and cobalt are solubilized in a solution, they are under the form of a coordination complex, they are then called “metal complexes”, “nickel complexes”, “manganese complexes” and “cobalt complexes”.
[0026] In the feed material, when nickel, manganese and cobalt are under their oxidized form, their oxidized form may be of the same type or may be of a different type, i.e. the ligand(s) surrounding each valuable metal may be the same or may be different than the ligand surrounding the other valuable metal(s). Preferably, the oxidized forms of nickel, manganese and cobalt are of the same type.
[0027] The feed material may comprise different oxidized form for a same valuable metal, for example Mn(0H)2 and MnO?.
[0028] The ligand surrounding nickel, and manganese and / or cobalt in the feed material may be chosen among hydroxide, chloride, sulphate, oxide, sulphide, carboxylate, carbonate, dihydrogen phosphate, nitrate, hydrogen phosphate, bicarbonate, acetate, and a mixture of these ligands. Preferably, nickel, and manganese and / or cobalt compounds are of the same type and are under the form of metal hydroxide, i.e. each of nickel, and manganese and / or cobalt are surrounded by hydroxide ligands.
[0029] Preferably, the feed material comprises at least 30% by weight of nickel, preferably at least 40% of nickel, and at least 2% by weight of cobalt and / or manganese, over the total weight of the feed material on a dry basis.
[0030] The feed material further comprises at least one undesired metal, in particular metal chosen among aluminium (Al), magnesium (Mg), copper (Cu), iron (Fe), zinc (Zn), chromium (Cr), calcium (Ca), scandium (Sc), and one of their mixtures.
[0031] In the present description, an undesirable metal is a metal which is present in the feed material and which is not suitable in the final pulp.
[0032] The undesired metals do not comprise any nickel, manganese and cobalt.
[0033] In the present description when an undesired metal is solid, that is under its oxidized form or under the metallic form, it is called “metal compound”. Further, when an undesired metal is in a solution under the form of a coordination complex, it is called “metal complex”.
[0034] When the feed material comprises more than one undesired metal under its oxidized form, their oxidized form may be of the same type or may be of a different type, i.e. the ligand(s) surrounding each undesirable metal may be the same or may be different than the ligand (s) surrounding the other valuable metal(s).
[0035] When an undesired metal is under its oxidized form in the feed material, the ligand(s) may be chosen among hydroxide, chloride, sulphate, oxide, sulphide, carboxylate, carbonate, dihydrogen phosphate, nitrate, hydrogen phosphate, bicarbonate, acetate, and a mixture of these ligands.
[0036] The feed material may comprise different oxidized forms of a same undesired metal.
[0037] The amount of each undesired metal in the feed material may be the same or may be different and may range from 0,05% to 40% in mass relative to the total mass of the feed material, preferably from 0,10 to 20% by weight relative to the total weight of the feed material on a dry basis.
[0038] The feed material may also comprise impurities which may be any compound which does not comprise a metal, in particular organic compounds, and for example sulphur compounds, sulphide compounds, sulphate compounds, graphite, fluoride compounds, silicium, phosphate compounds, and the like?
[0039] The amount of each impurity in the feed material may be less than 15% by weight relative to the total weight of the feed material, preferably less than 10% by weight relative to the total weight of the feed material, and most preferably less than 7% by weight relative to the total weight of the feed material, on a dry basis. Preferably, the feed material comprises less than 10% of silicium by weight over the total weight of the feed material.
[0040] Further, the total amount of all impurities in the feed material may be less than 30% by weight relative to the total weight of the feed material, preferably less than 20% y weight relative to the total weight of the feed material, and most preferably less than 10% by weight relative to the total weight of the feed material, on a dry basis.
[0041] The feed material may further comprise water.
[0042] Step EQ:
[0043] In the step E0, a pre-leaching step is performed using an acidic solution at a pH ranging from 5 to 8, and preferably from 6 to 7. The acid used in this step is chosen among water, hydrochloric acid, sulfuric acid, or any other organic or inorganic acid.
[0044] This step aims at solubilizing selectively at least one undesired metal complex while the valuable metals complexes all remain in a solid state, i.e. at least 95% of each valuable metal remains in a solid state.
[0045] A filtration is performed to separate the solid valuable metal complexe(s) and the solid undesirable metal complexe(s) from the solubilized undesired metals.
[0046] Some impurities such as sulphate may also be solubilized at this step.
[0047] The undesired metal complexes removed at this step may be or example magnesium and / or calcium.
[0048] If the feed material comprises magnesium, the amount of magnesium removed at this step ranges from 50% to 95% by weight, and preferably from 70% to 95% by weight, relative to the total weight of the magnesium in the feed material, on a dry basis.
[0049] The feed material which is usually solid may be crushed as a powder before performing step E0.
[0050] Step E0 may be performed at a temperature ranging from 5°C to 95 °C, preferably from 30° C to 90° C, and most preferably from 50° C to 70° C.
[0051] Step E1
[0052] In step E1 , the valuable metal(s) and remaining undesirable metal(s) are transformed in their chloride complexes in an aqueous solution.
[0053] Step E1 may be performed using a reagent chosen among hydrochloric acid, sodium hypochlorite, gaseous chlorine, and one of their mixtures.
[0054] According to a first embodiment, step E1 may be performed using hydrochloric acid, in particular aqueous hydrochloric acid. According to a variant of this embodiment, the feed material may be placed in water and then aqueous hydrochloric acid may be added. According to another variant of this embodiment, the feed material may be placed directly in an aqueous solution of hydrochloric acid.
[0055] According to a second embodiment, step E1 may be performed using sodium hypochlorite. According to a variant of this embodiment, the feed material may be placed in water and then sodium hypochlorite may be added. According to another variant of this embodiment, the feed material may be placed directly in an aqueous solution of sodium hypochlorite.
[0056] According to a third embodiment, step E1 may be performed using gaseous chloride. According to this embodiment, the step E1 is performed by bubbling gaseous chlorine is an aqueous solution of feed material.
[0057] According to the three possible embodiments, step E1 is performed at a pH value such that the residual acidity of the aqueous solution is comprised between 0,02 and 1 mol / L of acidic protons (H+). The pH may be for example lower than 2.
[0058] Step E1 which is a leaching step allows to transform valuable metals and undesired metals in their chloride complexes. These chloride complexes are soluble in the aqueous solution obtained at the end of step E1 .
[0059] Step E1 may be performed at a temperature ranging from 5°C to 95 °C, preferably from 30° C to 90° C, and most preferably from 50° C to 90° C. The leaching step is for example performed at a temperature of 80° C.
[0060] According to an embodiment, the feed material may comprise valuable metal(s) and / or undesired metal(s) at an oxidation state which needs to be modified, in particular to render the corresponding compound(s) soluble in the aqueous solution of step E1. The oxidation state may therefore be modified during step E1 by the addition of a reducing or oxidizing agent.
[0061] The reducing agent may for example be, a peroxide such as hydrogen peroxide, sodium sulphite, sodium dithionite, sodium thiosulfate, ascorbic acid, citric acid, and the like.
[0062] The oxidizing agent may for example be chlorine gas, sodium hypochlorite, bleach water.
[0063] The reducing agent may be added in an amount allowing to place the aqueous solution of step E1 at an oxidation / reduction potential (or redox potential) allowing to transform all the metal complexes in soluble complexes. According to this embodiment, the aqueous solution of step E1 is placed at a redox potential having a value ranging from 0 millivolts (mV) Ag / AgCl to 1200 mV Ag / AgCl, preferably from 300 mV Ag / AgCl to 1000 mV Ag / AgCl.
[0064] The valuable metal compounds which need to be reduced may be for example manganese oxides such as MnO? and cobalt oxides such as C0O2, C03O4, cobalt hydroxide such as Co(OH)3. According to a possible embodiment, during step E1 , it is possible to add a certain amount of nickel, manganese and / or cobalt in order to adjust the ratio Ni / Mn / Co and obtain the suitable ratio in the prepared mixture, i.e. the final solution comprising at least one of nickel, manganese and cobalt. The addition of nickel, manganese and / or cobalt may be done by the addition of a corresponding chloride complex or any compound which will be transformed in chloride complex during step E1 , such as those already listed regarding the feed material. Preferably, added valuable metal compounds may be under the form of hydroxide or carbonate complex(es).
[0065] Step E2
[0066] Step E2 aims at separating the undesirable metals and impurities, if any, from the valuable metals to obtain a composition free of undesired metals and impurities.
[0067] In the present description, the expression “free of” regarding a compound, i.e. a valuable metal, an undesirable metal or an impurity, refers to the amount of such compound in a solution and means that said solution comprises less than 100 mg / L of said compound, preferably less than 5 mg / L, and most preferably less than 1 mg / L.
[0068] In particular, this step involves a reaction which transforms the valuable metal complexes and / or the undesired metal complexes so that valuable metal complexes and undesired metal complexes have a different behaviour in a reaction medium. A different behaviour includes a different solubility depending on the pH of a solution, a different solubility depending on redox potential of a solution, a different partition coefficient in a mixture of two immiscible solvents.
[0069] Advantageously, in the case where the aqueous solution comprises two or three valuable metals, the separation method is chosen so that, during and at the end of the separation, valuable metal(s) have the same behaviour and are kept together.
[0070] Accordingly, step E2 may comprise at least one method chosen among a hydrolysis to obtain a specific pH; a modification of the redox potential of the solution; a filtration; a separation by solvent, in particular an organic solvent; a cementation on a metallic powder; a separation by ion exchange; or a combination of two or more of these methods.
[0071] According to an embodiment, step E2 may comprise a hydrolysis which may be basic or acidic and which may allow to transform the valuable metal(s) and / or the undesirable metal(s) to obtain a difference of solubility between the valuable metal(s) and the undesirable metal(s) at a predetermined pH. According to this embodiment, a filtration may be performed to separate the valuable metal(s) and / or the undesirable metal(s) after the hydrolysis step. According to a preferred embodiment, step E2 may comprise a basic hydrolysis using a base chosen among sodium hydroxide (NaOH); sodium carbonate (Na2CO3); cobalt hydroxide CO(OH)2), nickel hydroxide Ni(OH)2, manganese hydroxide Mn(0H)2, or a mixture of at least two of them; sodium bicarbonate (NaHCOs); and one of their mixtures. Preferably, the base used for the basic hydrolysis may be sodium carbonate (Na2CO3) or sodium hydroxide (NaOH).
[0072] When a basic hydrolysis is performed, the undesired metals complexes are transformed into a corresponding insoluble compound while valuable metal(s) remain(s) soluble under the form of chloride complexes. Advantageously, the pH is chosen so that the chloride complexes of the valuable metal(s) are not hydrolysed and remain soluble in the aqueous solution under their chloride form while the compounds of undesired metals are not soluble.
[0073] In particular, during basic hydrolysis, the aqueous mixture may have a pH ranging from 1 ,5 to 7, preferable from 2 to 6, and most preferably from 3 to 5. For example, the basic hydrolysis in step E2 is performed at a pH of 4.
[0074] Some hydroxide complexes such as hydroxides of aluminum (Al), copper (Cu), iron (Fe), zinc (Zn), chromium (Cr), calcium (Ca), scandium (Sc), and one of their mixtures, may precipitate at the above-mentioned pH.
[0075] According to this preferred embodiment, the basic hydrolysis may be performed at a temperature ranging from 20° C to 95 °C, preferably from 30° C to 90° C, and most preferably from 50° C to 90° C.
[0076] As a first example of step E2, a hydrolysis using sodium hydroxide may be performed during step E2 to transform the undesired metal(s) under the form of a hydroxide complex while maintaining the pH at a value at which undesirable metal(s) hydroxides precipitate and valuable metal(s) remain soluble under the form of a chloride complex. A filtration allows to separate the solid undesirable metal(s) hydroxides from the valuable metal chlorides which are soluble.
[0077] According to a second example of step E2, step E2 may comprise the extraction by an extractant solvent which forms an organic complex with the undesired metal(s) to subsequently separate the undesired metals from the aqueous solution by an extraction step with an organic solvent. Such solvent may be for example an organophosphorus solvent, in particular an organophosphorus acid such as di(2-ethylhexyl)phosphoric acid, bis(2,4,4- trimethylpentyl)phosphinic acid, mono-2-ethylhexyl (2-ethylhexyl)phosphonate, phosphate tributyl, trialkyl phosphine oxide; a carboxylic acid; an aliphatic amine; or one of their mixture. The organophosphorus solvent may be preferably the bis(2,4,4- tri methylpentyl) phosphi nic aci d .
[0078] According to a third example of step E2, step E2 may comprise a basic hydrolysis according to the first example followed by an extraction by solvent according to the second example, or an extraction by solvent according to the second example followed by a basic hydrolysis according to the first example.
[0079] According to a possible variant of a basic hydrolysis, oxygen may be added in the aqueous solution during hydrolysis. The oxygen may be added by introducing oxygen dioxide (0?) pure or from air. Such oxidant condition may allow to oxidize undesirable metals such as iron (II) into iron (III), which is subsequently hydrolysed in the corresponding hydroxide complex.
[0080] Step E2 may also comprise a first additional step A1 of activated carbon filter purification. Such step would allow to trap impurities and contaminants such as volatile organic compounds and contaminants if any, by the activated carbon porous structure.
[0081] Step E2 may also comprise a second additional step A2, especially when the feed material comprises magnesium complex(es) which was not totally removed at step EO. Second additional step A2 comprises the addition, in the intermediate solution of valuable metals obtained after step E2, and optionally after first additional step A1 , of sodium fluoride (NaF). This step allows to precipitate magnesium into an unsoluble fluoride complex. If the intermediate solution comprises calcium, it is also precipitated and removed at this step. After addition of sodium fluoride, an intermediate mixture comprising undesired metal under the form of a solid fluoride complex, such as for example magnesium fluoride (MgF?) and calcium fluoride (CaF?), is obtained.
[0082] The intermediate solution may comprise an amount of magnesium ranging from 3 to 10 g / L.
[0083] The second additional step A2 may be performed at a pH ranging from 1 to 6, preferably from 1 ,5 to 5, and most preferably from 2,5 to 3,5.
[0084] The second additional step is performed at a temperature ranging from 20° C to 80° C, preferably from 40° C to 60° C
[0085] A filtration may be performed on the intermediate mixture to separate the solid fluoride complex(es) and a second intermediate solution.
[0086] Step E3
[0087] Following step E2, an aqueous solution, called intermediate solution, and comprising the valuable metals under the form of the chloride complex, i.e. NiCb, MnCb and / or CoCb, and free of undesired metals and impurities if any is obtained.
[0088] In the case where first additional step A1 is performed, the second intermediate solution is obtained.
[0089] In step E3, sodium hydroxide, sodium carbonate, or sodium bicarbonate is added to the intermediate solution, or to the second intermediate solution, at a pH allowing the hydrolysis of the valuable metal(s) chloride complexe(s) into the corresponding solid hydroxide, carbonate or bicarbonate compounds, i.e. Ni(OH)2, and Mn(0H)2 and / or Co(OH)2; or Ni(CO3), and Mn(C03) and / or Co(C03); or Ni(HCO3)2, and Mn(HCO3)2 and / or Co(HC03)2. At this step, at least 70% by weight of each of the valuable metal(s) chloride complexe(s) are hydrolysed in the corresponding solid hydroxide, carbonate or bicarbonate compounds, preferably at least 85% by weight, relative to the weight of each compound in the intermediate solution on a dry basis.
[0090] This precipitation step E3 may be performed at a pH ranging from 6 to 10, and preferably from 7 to 9.
[0091] As byproduct, this precipitation step forms a solution of sodium chloride.
[0092] Step E4
[0093] The mixture comprising nickel, and manganese and / or cobalt hydroxides, carbonate, or bicarbonate and sodium chloride is then filtered in step E4 to obtain a wet solid comprising nickel, and manganese and / or cobalt hydroxides, carbonate, or bicarbonate and a filtrate solution of sodium chloride.
[0094] The wet solid may then be washed and dried to obtain a powder of solid nickel, manganese and / or cobalt hydroxides free from undesired compounds.
[0095] This final solid may present various ratios of nickel, and manganese and / or cobalt depending on the ratio of the feed material and on possible addition of one or more of nickel, manganese and cobalt during the process. Such addition may be performed in an adjustment step, preferably before step E3.
[0096] Further, the final solid may be free of undesired metal, i.e. metals other than nickel, manganese and cobalt, and free of impurities.
[0097] The adjustment step may be performed before step E3 to modify the ratio of nickel, manganese and cobalt, in particular by the addition of one or more of these metals under the form of a complex, preferably a chloride complex.
[0098] Step E5
[0099] The process may also comprise a step E5 during which an electrolysis is performed with the solution of sodium chloride obtained at step E4. This electrolysis allows to obtain a solution containing sodium hydroxide and gaseous dihydrogen and chlorine.
[0100] Gaseous dihydrogen and chlorine are then used in a combustion process to produce gaseous hydrogen chloride. The gaseous hydrogen chloride is trapped with water to produce hydrochloric acid.
[0101] Step E6 The process may also comprise a step E6 comprising the used of chlorine gas or hydrochloric acid prepared at step E5 to perform another leaching step in step E1 .
[0102] Further, sodium hydroxide obtained at step E5 may be used to perform another precipitation step E3.
[0103] Step E4 and E5 therefore allow to prepare hydrochloric acid and sodium hydroxide from sodium chloride and limit the waste of sodium chloride and also the use of commercial hydrochloric acid and / or sodium hydroxide.
[0104] DESCRIPTION OF THE FIGURES
[0105] [Fig. 1] shows the steps of an exemplary process according to the invention.
[0106] EXAMPLE
[0107] In this example, the feed material is a mixture comprising 70 % of a mixed hydroxides precipitate (MHP) comprising nickel, manganese and cobalt as hydroxide compounds, undesired metals and impurities, and of 30 % of black mass (BM). This example aims at preparing a pCAM product useful for batteries fabrication.
[0108] During the process, the mixture obtained may be analysed by Inductively Coupled Plasma (ICP) spectroscopy, Auger Electron Spectroscopy (AES), Inductively Coupled Plasma (ICP) spectroscopy combined with mass spectrometry or X-Ray diffraction analysis (XRD). The MHP is an intermediate product derived from the hydrometallurgical process of a nickel ore. The feed material has composition presented in table 1 below, the amount of valuable metals, undesired metals and impurities being given in a dry basis. Pre-leaching step Eo is performed using a mass ratio of liquid (water) on solid (BM+MHP) of 1 during 180 min at a temperature of 50° C. After filtration, a wet solid is obtained having the following composition on a dry basis :
[0109] Step EO allowed to eliminate more than 90% of magnesium.
[0110] Leaching step E1 is performed using 1.5 kg of the wet solid in a mixture of 1.6 L of water, 2.4 L of hydrochloric acid at 35%wt, and 0.15 L of hydrogen peroxide at 35%wt as reducing agent.
[0111] The mixture is agitated during 2h at a temperature of 80° C in the aqueous solution which has residual acidity comprised between 0,02 and 1 mol / L of acidic protons (H+)
[0112] This step E1 allows to reduced Mn(IV) in Mn(ll) and Fe(lll) in Fe(ll) and also to transform all the hydroxide complexes in the corresponding chloride complexes, in particular valuable metal chlorides and undesired metal chlorides, with an efficiency of at least 95%, preferably 99%. An acidic mixture S1 is obtained having the following composition:
[0113] In a step E2, the acidic mixture S1 then undergoes a basic hydrolysis (H1 ) using a mixture of Na?(C03) and Na(OH as a base with the addition of dioxygen coming from ambient air. This hydrolysis step is performed at a pH of 4, at a temperature of 80° C and for a duration of 2h.
[0114] During this step, nickel, manganese, cobalt remain under the form of their chloride complex and undesired metals are transformed into their hydroxide complex. Further, FeCb is oxidized in its degree III oxidation state and then hydrolysed into Fe(OH)3.
[0115] At this end of the basic hydrolysis, a mixture S2 is obtained wherein most of Fe(OH)3, Al(OH)3, Cr(OH)3 precipitate and are eliminated by filtration (F1 ) while NiCb, MnCb, CoCb and ZnCb remain soluble in the filtrate solution S3.
[0116] Still in step E2, the filtrate solution S3 then undergoes a separation by solvent step (Ext1 ) which is a purification by extraction using bis(2,4,4-trimethylpentyl)phosphinic acid (called A-PHOS) as extractant in an aliphatic solvent. In this example, the solvent is an aliphatic solvent commercialized under the reference Shellsol D70 or D90 and the bis(2,4,4- tri methylpentyl) phosphinic acid is commercialized under the reference Cyanex 272.
[0117] This additional extraction step comprises four sub-steps which are a saponification of the extractant, an extraction sub-step, a scrubbing sub-step and a stripping sub-step. Each sub-step comprises a four extraction stages, six scrubbing stages and four stripping stages.
[0118] The saponification sub-step is performed on a solution of PHOS in the aliphatic solvent wherein aqueous sodium hydroxide is added to transform A-PHOS-H+into A-PHOS-Na+. The saponified extractant A-PHOS-Na+is in the organic phase and is used in the extraction substep.
[0119] During extraction sub-step, the filtrate solution S3 is contacted with A-PHOS-Na+in the organic phase mixture. An ion exchange reaction occurs between sodium and some metals of the filtrate solution S3 to obtain metal complexes with A-PHOS in the organic phase. In particular, A-PHOS-Zn2+, A-PHOS-Ca2+are form in a high efficiency of at least 95% and A-PHOS-Mn2+is also formed at a level of around 6%. The following complexes are also formed at a low level of less than 2% : A-PHOS-Ni2+and A-PHOS-Co2+. Therefore, during this extraction step, nickel and cobalt mainly remain in the aqueous phase under the form of their chloride complex(es).
[0120] An aqueous solution S4 free of most undesired metals is obtained after extraction.
[0121] In order to retrieve the valuable metals nickel, manganese and cobalt inevitably extracted, the organic phase is washed with a diluted solution of hydrochloric acid having a pH of 1 to 2.
[0122] A stripping stage may also be performed with hydrochloric acid having a pH of 0 to 1 to remove all metals from the organic phase and recycle the A-PHOS organic phase to the saponification sub-step. The acidic aqueous phase from the stripping sub-step contains all extracted undesired metals and impurities and is sent to a rejection step.
[0123] The aqueous solution S4 comprising NiCb, MnCb and CoCb is filtered in a first additional step A1 on an activated carbon cartridge to remove organic contaminants on the porous carbon structure, in particular organic compounds.
[0124] The filtered aqueous solution S5 comprises NiCb, MnCb and CoCband only few remaining undesired metals such as magnesium, and few impurities.
[0125] The composition of solution S5 is indicated in the table below:
[0126] If necessary, to obtain the right ratio (or molar stoichiometry) of nickel, manganese and cobalt, i.e. 8 / 1 / 1 , an adjustment step may be performed by adding the suitable amounts of pure NiCb, MnCb and / or CoCb to the solution S5. A second additional step A2 is then performed on solution S5 using sodium fluoride such that remaining magnesium and calcium are transformed into their insoluble fluoride complex. This step is performed at a pH ranging from 2,5 to 3,5 and at a temperature of 30° C to 50° C. After filtration, a solution S5’ having the following composition is obtained:
[0127] Step E3 is now performed on filtered aqueous solution S5’ to precipitate NiCb, MnCb and CoCb under the form of insoluble hydroxide compounds by the addition of a solution of sodium hydroxide (NaOH) to the solution S5’ to reach a pH between 6 and 6,5. At this pH, at least 95% of each of nickel, cobalt and manganese precipitate into their insoluble hydroxide form. The pulp S6 comprising Ni(OH)?, Mn(OH)? and Co (OH)? obtained is filtered in a step E4 and the filter cake (P1 ) is washed (W1 ) and represents the final product (FP). The final product is dried and packaged for selling.
[0128] In the final product, the amount of the mixture of nickel, manganese and cobalt is of 62% by mass over the total mass of the final product on a dry basis. The amount of remaining undesirable metals and impurities are indicated in the the table below:
[0129] The filtrate from step E4 still contains some metals, traces of nickel, manganese and cobalt. These metals are precipitated by addition of Na?CO3 at a pH of 10. Metals form insoluble carbonate compounds. The pulp obtained is filtered. The solid phase is rejected from the process and the filtrate S7, containing mainly NaCl, is sent to step E5.
[0130] The filtrate S7 is then purified (P1 ) according to a known process to be able to undergo an electrolysis, for example reverse osmosis, metal traces elimination by ion exchanges, or the like. The resulting solution is named S8.
[0131] In step E5, an electrolysis is performed on solution S8 allowing to obtain a solution containing sodium hydroxide and gaseous dihydrogen and chlorine.
[0132] Gaseous dihydrogen and chlorine are then used in a combustion process to produce hydrochloric acid.
[0133] In step E6, hydrochloric acid prepared at step E5 is used to perform another leaching process in another step E1 . Further, sodium hydroxide is used to perform another step E3.
[0134] In this example, the process of the invention allows to prepare nickel, manganese and cobalt hydroxide using a feed material containing nickel, cobalt and manganese compounds without separating one of these metals from the others during the process.
[0135] In the example, the process also allows to prepare and recycle hydrochloric acid and sodium hydroxide using the solution obtained after the preparation of nickel, manganese and cobalt hydroxides in step E3.
[0136] This process therefore limits the waste of effluent and also limits the use of commercial hydrochloric acid and / or sodium hydroxide.
[0137] Further, in this example, this process allowed to prepare pCAM (cathode active material precursors) starting with MPH without separation of nickel, manganese and cobalt from each other during the process.
Claims
CLAIMS1. Process of preparation of a mixture comprising at least two valuable metal compounds, said at least two valuable metals compounds being a nickel complex, and a cobalt and / or a manganese complex(es), from a feed material comprising said at least two valuable metal compounds and at least one undesired metal compound(s), the amount of valuable metals being at least 30% by weight over the total weight of the feed material, the process comprising the steps of:- E0 : performing a pre-leaching of the feed material at a pH having a value ranging from 6 to 8 to obtain a pulp, followed by a filtration to obtain a wet solid and a filtrate ;- E1 : performing a leaching on the wet solid to transform the at least two valuable metal compounds and the at least one undesired metal compound(s) of the wet solid to the corresponding chloride complexes in an aqueous solution such that the residual acidity is comprised between 0,02 and 1 mol / L of acidic protons (H+);- E2: separating selectively the at least one undesired metal complexe(s) from the at least two valuable metal complexes to obtain an intermediate solution free from undesired metals complexes;- E3: adding a base chosen among sodium hydroxide, sodium carbonate, and sodium bicarbonate, to the intermediate solution to precipitate the at least two valuable metals under the form of the corresponding hydroxide, carbonate or bicarbonate compounds in a final pulp; and- E4: filtering the final pulp to obtain a powder of the at least two valuable metal hydroxides, carbonate or bicarbonate and a solution of sodium chloride, the powder comprising at least 45% by weight of the valuable metals over the total weight of the pulp.
2. The process according to claim 1 , wherein step E1 is performed using a reagent chosen among hydrochloric acid, sodium hypochlorite, gaseous chlorine, and one of their mixtures.
3. The process according to claim 1 or 2, wherein step E1 comprises the addition oxidizing reagent or reductive reagent to adjust the redox potential of the aqueous solution.
4. The process according to anyone of the preceding claims, wherein step E2 allows to transform the at least one valuable metal(s) and / or the at least one undesired metal so that valuable metal complexes and undesired metal complexes have a different behaviour in a reaction medium.
5. The process according to claim 4, wherein the different behaviour includes a different solubility depending on the pH of a water composition, a different solubility depending on redox potential of a solution, a different partition coefficient in a mixture of two immiscible solvents.
6. The process according to anyone of the preceding claims, wherein step E2 comprises at least one method chosen among a hydrolysis to obtain a specific pH; a modification of the redox potential of the solution; a filtration; a separation by solvent, in particular an organic solvent; a cementation on a metallic powder; a separation by ion exchange; or a combination of two or more of these methods.
7. The process according to anyone of the preceding claims, wherein step E2 comprises a basic hydrolysis using a base chosen among sodium hydroxide (NaOH); sodium carbonate (Na2CO3); cobalt hydroxide Co(OH)2), nickel hydroxide Ni(OH)2, manganese hydroxide Mn(OH)2, or a mixture of at least two of them; sodium bicarbonate NaHCO3; and one of their mixtures.
8. The process according to anyone of the preceding claims, wherein step E2 comprises a separation by solvent using an extractant solvent chosen among an organophosphorus solvent, in particular an organophosphorus acid such as di(2-ethylhexyl)phosphoric acid, bis(2,4,4-trimethylpentyl)phosphinic acid, mono-2-ethylhexyl (2-ethylhexyl)phosphonate, phosphate tributyl, trialkyl phosphine oxide; a carboxylic acid; an aliphatic amine; or one of their mixture.
9. The process according to anyone of the preceding claims, wherein step E2 comprises a separation by solvent using bis(2,4,4-trimethylpentyl)phosphinic acid as extractant solvent.
10. The process according to anyone of the preceding claims, wherein step E1 further comprises a reductive component chosen among a peroxide such as hydrogen peroxide, sodium sulphite, sodium dithionite, sodium thiosulfate, ascorbic acid, citric acid, and one of their mixture.
11. The process according to anyone of the preceding claims, wherein step E2 comprises a second additional step A2 which comprises the addition, to the intermediate solution of valuable metals, of sodium fluoride to obtain an intermediate mixture.
12. The process according to claim 11 , wherein second additional step A2 comprises the filtration of the intermediate mixture to obtain a second intermediate solution.
13. The process according to anyone of the preceding claims, wherein step E3 is performed at a pH ranging from 6 to 10.
14. The process according to anyone of the preceding claims, further comprising a step E5 comprising an electrolysis of the solution of sodium chloride to obtain a solution containing sodium hydroxide and gaseous dihydrogen and chlorine.
15. The process according to claim 14, further comprising a burning step to form hydrogen chloride followed by a trapping step of gaseous hydrogen chloride with water to produce hydrochloric acid.
16. The process according to claim 14 or 15, further comprising a step E6 comprising the use of sodium hydroxide obtained at step E4 to perform another step E3 and / or the use of hydrochloric acid prepared at step E5 to perform another step E1 .
17. Process of preparation of cathode active material precursors (pCAM) using the process according to anyone of the preceding claims, using a mixed hydroxide precipitate (MHP) as feed material.