PROCESS FOR THE RECOVERY OF LITHIUM AND OTHER METALS FROM WASTE LITHIUM ION BATTERIES

Abstract

A process for the recovery of one or more transition metals and lithium from waste lithium ion batteries or parts thereof is disclosed. The process comprising the steps of (a) providing a particulate material containing a transition metal compound and/or transition metal, wherein the transition metal is selected from the group consisting of Ni and Co, and wherein further at least a fraction of said Ni and/or Co, if present, are in an oxidation state lower than +2, e.g. in the metallic state; which particulate material further contains a lithium salt; (b) treating the material provided in step (a) with a polar solvent and optionally an alkaline earth hydroxide; (c) separating the solids from the liquid, optionally followed by a solid-solid separation step; and (d) treating the solids containing the transition metal in a smelting furnace to obtain a metal melt containing Ni and/or Co provides good separation of transition metal as alloy and of lithium in high purity.

Claims

1-17. (canceled)

18. A process for recovering of one or more transition metals, and lithium as Li-salt from a particulate material comprising waste lithium ion batteries or parts thereof, wherein the process comprises: (a) providing the particulate material comprising a transition metal compound and/or transition metal, wherein the transition metal is chosen from Ni and Co, and wherein at least a fraction of the Ni and/or Co are in an oxidation state lower than +2 and the particulate material further comprises a lithium salt; (b) treating the particulate material of step (a) with a polar solvent; (c) separating solid residue comprising the transition metal from liquid of the particulate material of step (b), and optionally, subjecting the solid residue to a solid-solid separation for the removal of the transition metal; and (d) treating the solid residue of step (c) comprising the transition metal in a smelting furnace to obtain a metal melt comprising Ni and/or Co; wherein the solid residue separated in step (c) is subjected to the solid-solid separation for the removal of transition metal before step (d), and the polar solvent used in step (b) comprises an alkaline earth hydroxide.

19. The process according to claim 18, wherein the particulate material of step (a) is from spent lithium ion batteries and/or scrap material from producing lithium ion batteries or lithium ion cathode active materials, and is in a form of a dry powder, wet powder, or suspension of particles in a liquid.

20. The process according to claim 18, wherein the particulate material of step (a) comprises particles having an average particle diameter D50 ranging from 1 μm to 2 mm, when detected in accordance with ISO 13320 EN:2009-10.

21. The process according to claim 18, wherein the transition metal compound and/or transition metal Ni and/or Co in oxidation state lower than +2, comprised in the particulate material of step (a), comprises Ni and/or Co in the metallic state, and wherein the transition metal compound and/or transition metal comprised in the particulate material of step (a) is present in an amount detectable by powder x-ray diffractometry (Cu-k-alpha-1 radiation).

22. The process according to claim 18, wherein the lithium salt comprised in the particulate material of step (a) comprises one or more salts of LiOH, LiF, Li2O, Li2CO3, LiHCO3, lithium alum inates, lithium phosphate salts, and mixed oxides of Li and one or more of Ni, Co, Mn, Fe, Al, Cu.

23. The process according to claim 18, wherein treating in step (b) is carried out in presence of an alkaline earth hydroxide and comprises: i) adding the alkaline earth hydroxide and/or an alkaline oxide, as a solid, or a mixture comprising the alkaline earth hydroxide as suspension or solution in a protic solvent, and the particulate material of step (a) simultaneously to the polar solvent, which is a protic solvent; ii) adding the particulate material of step (a) to the polar solvent, which is a protic solvent, to obtain a suspension, followed by adding the alkaline earth hydroxide and/or an alkaline oxide, as a solid, or a mixture comprising alkaline earth hydroxide as suspension or solution in a protic solvent; iii) adding the alkaline earth hydroxide and/or an alkaline oxide, as a solid or suspension of solids in a polar solvent, to an aqueous liquid to obtain a mixture comprising alkaline earth hydroxide, and subsequently combining the mixture with the particulate material of step (a); iv) adding the alkaline earth hydroxide and/or an alkaline oxide, as a solid, to the particulate material of step (a) to obtain a mixture of solids, followed by adding the polar solvent, which is a protic solvent; or v) adding the particulate material of step (a) to the polar solvent, which is a protic solvent, to obtain a suspension, followed by filtering to obtain a filtrate, and subsequently adding the alkaline earth hydroxide and/or an alkaline oxide, as a solid, or a mixture comprising alkaline earth hydroxide to the filtrate.

27. The process according to claim 18, wherein the polar solvent of step (b) comprises calcium hydroxide, which is added to the polar solvent, or is formed in situ upon contact of calcium oxide with the polar solvent chosen from protic solvents.

28. The process according to claim 18, wherein the particulate material of step (a) comprises waste lithium ion batteries after carrying out a preliminary step (i) of heating under inert or reducing conditions to a temperature ranging from 80° C. to 900° C., wherein the preliminary step (i) is carried out after discharging the lithium ion batteries, dismantling, and/or shredding.

29. The process according to claim 28, wherein the preliminary step (i) is conducted under reducing conditions comprising the presence of carbon and/or a reducing gas chosen from hydrogen and carbon monoxide.

30. The process according to claim 28, wherein in the preliminary step (i), the temperature ranges from 350° C. to 500° C., and the preliminary step (i) is conducted in the presence of 35% or more by volume of hydrogen; or wherein in the preliminary step (i), the temperature ranges from 500° C. to 850° C., and the preliminary step (i) is conducted in the presence of carbon in an atmosphere containing up to 20% by volume of oxygen.

31. The process according to claim 18, wherein the particulate material of step (a) is from lithium ion batteries after mechanic removal of casing, wiring or circuitry and discharging, and wherein the particulate material is not exposed to temperatures of 400° C. or more under oxidizing conditions before step (a).

32. The process according to claim 18, further comprising subjecting the solids in step (c) to a solid-solid separation.

33. The process according to claim 18, wherein the solids comprising the transition metal are dried to a residual content of liquids below 5% and/or the solids are pelletized before step (d).

34. The process according to claim 18, wherein in step (d), the temperature in the furnace at the tapping points ranges from 1200° C. to 1600° C., and the furnace is operated in continuous mode or in batch mode.

35. The process according to claim 18, wherein the solids treated in step (d) further comprise one or more of copper, iron and manganese.

36. The process according to claim 18, further comprising recovering lithium as lithium hydroxyde by crystallization from the liquid in step (c), or recovering lithium as lithium carbonate after adding carbon dioxide to the liquid in step (c) and isolating the lithium carbonate formed.

37. A solid alloy produced by the process of claim 18 upon cooling the melt obtained in step (d).

Description

EXAMPLE 1: PROVIDING A REDUCED MASS FROM WASTE LITHIUM ION BATTERIES

[0205] An amount of about 1 t mechanically treated battery scrap containing spent cathode active material containing nickel, cobalt and manganese, organic carbon in the form of graphite and soot and residual electrolyte, and further impurities inter alia comprising fluorine compounds, phosphorous and calcium is treated to obtain a reduced mass according to the process described in Jia Li et al., Journal of Hazardous Materials 302 (2016) 97-104. The atmosphere within the roasting system is air whose oxygen reacts with the carbon in the battery scrap to form carbon monoxide, treatment temperature is 800° C.

[0206] After reaction and cool down to ambient temperature, the heat-treated material is recovered from the furnace, mechanically treated to obtain a particulate material and analyzed by means of X-ray powder diffraction (FIGS. 1 and 2: Mo Ka radiation, FIGS. 3 and 4: Cu Ka radiation), elemental analysis (Tab. 2) and particle size distribution (Tab. 3).

[0207] The Li content is 3.6 wt.-%, which acts as reference for all further leaching examples (see below). Fluorine is mainly represented as inorganic fluoride (88%). Particle sizes are well below 1 mm; D50 is determined to be 17.36 μm.

[0208] Comparing the obtained XRD pattern with calculated reference patterns of Ni (which is identical with that one of CoxNi1−x, x=0-0.6), Co, Li2CO3 and LiAlO2 (see reference patterns in Tab. 1), it can be concluded that Ni is exclusively present as metallic phase, either as pure Ni or as an alloy in combination with Co. For clarity, this result is confirmed by applying two different radiation sources. The presence of metallic nickel is supported by the qualitative observation that the whole sample shows typical ferromagnetic behavior when it gets in touch with a permanent magnetic material. As lithium salts, Li2CO3 as well as LiAlO2 are clearly identified by their characteristic diffraction pattern.

[0209] The composition of the black powder (PM) obtained is shown in Table 2.

TABLE-US-00002 TABLE 2 Composition of reduced black powder (PM) F (ionic F thereof) 2.6 g [i.e. 0.14 mol]/100 g (2.3 g [i.e. 0.12 mol]/100 g) C (inorganic C thereof) 31.3 g/100 g (1.2 g/100 g) Ca 0.16 g [i.e. 0.004 mol]/100 g Co  9.5 g/100 g Cu  3.4 g/100 g Li  3.6 g/100 g Mn  5.8 g/100 g Ni  4.8 g/100 g P 0.36 g/100 g

TABLE-US-00003 TABLE 3 Results on particle size distribution measurement of reduced mass from waste lithium ion batteries after heat treatment. D10 [μm] D50 [μm] D80 [μm] D90 [μm] 3.46 17.36 33.86 48.92

EXAMPLE 2: LEACHING WITH CA(OH)2

[0210] An amount of 5 g of the above-mentioned reduced battery scrap material (obtained as shown in Example 1) is filled an a PFA flask and mixed with 5, 1.5, 1.0 and 0.5 g of solid Ca(OH)2, respectively. 200 g of water are added with stirring, and the whole mixture is refluxed for 4 hours.

[0211] After 4 hours, the solid content is filtrated off and filtrate samples are taken and analyzed with regard to Li, F, carbonate, OH, and Ca. Results are compiled in the below Table 4.

TABLE-US-00004 TABLE 4 Analyzed filtrates after Li leaching with Ca(OH)2. Amount of Lithium Fluoride Li leaching Ca(OH).sub.2 content content efficiency [g] [mg] [mg] [%] 0.5 144 46 80 1.0 154 12 84 1.5 156 4 86 5 162 4 90

EXAMPLE 2A: LEACHING WITH CA(OH)2, ADDITION OF SOLIDS TO LIQUID

[0212] Example 2 is repeated except that 5 g of the black powder obtained as shown in Example 1, and the designated amount of solid Ca(OH)2, are added simultaneously to 200 g of water with stirring. Results are analogous to those reported in Table 4.

EXAMPLE 3: HIGHER SOLID CONTENT

[0213] An amount of 10, 20 and 30 g, respectively, of the particulate material (PM) described in example 1 is filled an a PFA flask and mixed with solid Ca(OH)2 in a fixed weight ratio of PM:Ca(OH)2=3.3:1. The further treatment with addition of 200 g of water follows example 2 except that each sample is refluxed for 6 hours. Results are shown in Table 5.

[0214] Based on these results, it is concluded that the efficiency of the present leaching process is not affected by the PM solid content.

TABLE-US-00005 TABLE 5 Analyzed filtrates after Li leaching with Ca(OH)2. Amount of Lithium Fluoride material from content content Li leaching example 1 [mg] [mg] efficiency 10 g 322 10 89% 20 g 624 20 86% 30 g 987 30 91%

EXAMPLE 4: VARIATION OF PARAMETERS

[0215] Following the procedure of Example 2a, solid Ca(OH)2 and the particulate material (PM) described in example 1 is added with stirring (3 stages cross-beam stirrer, 60 mm diameter) to 836.8 g of pre-heated water in a glass reactor with baffles. The stirring is continued at constant temperature for the time period (t) indicated in Tab. 6, after which the solid is filtered off and filtrate samples are analyzed. Amounts of Ca(OH)2 and PM, temperatures, stirring parameters, and analysis results (%=g found in 100 g of filtrate) are also compiled in Table 6.

TABLE-US-00006 TABLE 6 recovered t Li F.sup.− Li Sample [h] [%] [%] [%] 125.5 g PM, 0 37.7 g Ca(OH).sub.2 2 0.28 0.024 55% T = 70° C., 3 0.28 0.022 55% stir with 525 rpm 4 0.30 0.021 59% (0.85 W/kg) 6 0.33 0.014 65% 24 0.41 0.007 80% 125.5 g PM, 0 37.7 g Ca(OH).sub.2 2 0.41 0.016 80% T = 95° C., 3 0.43 0.015 84% stir with 525 rpm 4 0.44 0.015 86% (0.85 W/kg) 6 0.47 0.014 92% 24 0.48 0.014 94% 125.5 g PM, 0 37.7 g Ca(OH).sub.2 2 0.42 0.014 82% T = 98° C., 3 0.43 0.013 84% stir with 950 rpm 4 0.45 0.013 88% (5 W/kg) 6 0.45 0.013 88% 24 0.48 0.016 94% 167.4 g PM, 0 50.2 g Ca(OH).sub.2 2 0.49 0.019 72% T = 98° C., 3 0.53 0.018 78% stir with 600 rpm 4 0.54 0.018 79% (1.3 W/kg) 6 0.55 0.018 81% 24 0.64 0.029 94%

EXAMPLE 5: SOLID LIOH FROM LEACHED LITHIUM FILTRATE

[0216] A filtrate obtained from a process according to example 2 is further treated according to the above described step (e1) to yield solid LiOH as monohydrate: 1 L of a filtrate containing 0.21 wt.-% lithium is concentrated by evaporation (40° C., 42 mbar) and finally dried applying 40° C. and a constant flow of nitrogen for 24 h. FIG. 5 shows the obtained LiOH monohydrate with minor impurities of Li2CO3. The latter is due to contact with air during almost all process steps. Next to carbon-based impurities, elemental analysis reveals as main impurities (>200 ppm) F, Na, Ca, K and CI and minor impurities (<200 ppm) of Al and Zn.

EXAMPLE 6: LAB-SCALE SMELTING

[0217] The particulate mass (black powder) described in example 1 is leached according to example 4 for 6 h. The leached residue obtained after filtration contains approx. 2.2% total fluorine, 26.3% carbon, 13.9% calcium, 8% cobalt, 2.9% copper, 0.2% lithium, 4.9% manganese, 4.8% nickel and 0.3% phosphorous as dry mass. 4.23 kg of this material is slurried in water, additivated with 0.63 kg of fine quartz sand (d50 approx. 80 μm), 0.01 kg of calcium oxide and 0.51 kg of molasses. The slurry is filtered and extruded by an extruder press into a 6 mm strand. This strand is dried and calcined at 700° C. and broken into pieces of less than 1 cm length. This material is the feed for a smelting experiment in a lab-scale electric arc furnace.

[0218] A graphite crucible of 180 mm inner diameter and a height of 210 mm, whose inner wall surface (except for the bottom) is covered by an alumina paper of 5 mm thickness and lined with a chromium corundum casting (87.5% Al2O3, 10.5% Cr2O3, 2% CaO) of 30 mm thickness previously dried for 18 h at 120° C. followed by a burning at 515° C. for 18 h, is placed into a lab-scale electric arc furnace and embedded with graphite felt and sealed on top with refractory mortar. The crucible is then charged with coke and pre-heated with an open electric arc at 35 V and 100 A from the 50 mm diameter head electrode until the bottom and the surrounding side walls of the oven are glowing (approx. 950° C.). The coke is then discharged by tilting of the oven. Afterwards 516 g of carbon saturated cast iron serving as counter electrode for the electric arc are filled into the oven together with 250 g of feed material. After about 10 min the material is molten and the rest of the feed material is charged into the furnace in 100 g portions with 2 min between each charge. The electric power is increased to 11 kW (50 V, 225 A). After completion of the charging, the temperature in the oven is at approx. 1600° C. The electric power is reduced to 9 kW (60 V, 150 A) and the melt is kept for 10 min. Afterwards the electric power is switched off and the oven is cooled down to ambient temperature overnight. The cold crucible is discharged from the oven and crushed. At the bottom of the crucible about 1 kg of an alloy containing mainly nickel, cobalt and copper from the battery scrap material and iron.

[0219] The alloy components are separated according to methods known in the art.

BRIEF DESCRIPTION OF FIGURES

[0220] FIG. 1: X-ray powder diffractogram (Mo Ka) of reduced mass from waste lithium ion batteries after heat/reduction treatment as obtained in example 1 and used in example 2a including reference diffractograms of graphite, cobalt, manganese-II-oxide, cobalt oxide, and nickel.

[0221] FIG. 2: X-ray powder diffractogram (Mo Ka) of reduced mass from waste lithium ion batteries after heat/reduction treatment as obtained in example 1 and used in example 2a including reference diffractograms of graphite, lithium aluminate, and lithium carbonate.

[0222] FIG. 3: X-ray powder diffractogram (Cu Ka) of reduced mass from waste lithium ion batteries after heat/reduction treatment as obtained in example 1 and used in example 2a including reference diffractograms of graphite, cobalt, manganese-II-oxide, cobalt oxide, and nickel.

[0223] FIG. 4: X-ray powder diffractogram (Cu Ka) of reduced mass from waste lithium ion batteries after heat/reduction treatment as obtained in example 1 and used in example 2a including reference diffractograms of graphite, lithium aluminate, and lithium carbonate.

[0224] FIG. 5: X-ray powder diffractogram (Cu Ka) of LiOH monohydrate as obtained in example 5.