PROCESS FOR THE RECOVERY OF LITHIUM FROM WASTE LITHIUM ION BATTERIES

Abstract

A process for the recovery of 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 Mn, 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, and at least a fraction of said Mn, if present, is manganese(II)oxide; which particulate material further contains a lithium salt and a fluoride salt, and which particulate material optionally contains calcium provided that the element ratio calcium to fluorine is 1.7 or less or is zero; (b) treating the material provided in step (a) with a polar solvent and an alkaline earth hydroxide; and (c) separating the solids from the liquid, optionally followed by washing the solid residue with a polar solvent such as water provides good separation of lithium in high purity, and recovery of valuable transition metals.

Claims

1-17. (canceled)

18. A process for recovering lithium 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 Mn, Ni, and Co, and wherein further at least a fraction of the Ni and/or Co, if present, are in an oxidation state lower than +2, and at least a fraction of the Mn, if present, is manganese(II)oxide; and wherein the particulate material further comprises a lithium salt and a fluoride salt, and optionally, the particulate material comprises calcium with an element ratio of calcium to fluorine is 1.7 or less or is zero; (b) treating the particulate material in step (a) with a polar solvent and an alkaline earth hydroxide; and (c) separating solids from liquid of the particulate material in step (b), and optionally, washing the solid residue with a polar solvent.

19. The process of claim 18, wherein the particulate material of step (a) is from waste lithium ion batteries 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 provided in 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 provided in 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 and the fluoride salt of the particulate material of step (a) comprises one or more salts of LiOH, LiF, Li2O, Li2CO3, LiHCO3, lithium aluminates, lithium phosphate salts, and mixed oxides of Li and one or more of Ni, Co, Mn, Fe, Al, Cu and/or fluorides of Ni, Co, Mn, Fe, Al, Cu.

23. The process according to claim 18, wherein treating in step (b) 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 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; or v) adding the particulate material of step (a) to the polar solvent, which is a protic solvent, to obtain a suspension, followed by filtrating 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.

24. The process according to claim 18, wherein the alkaline earth hydroxide added in step (b) is calcium hydroxide added, or calcium hydroxide is formed in situ upon contact of calcium oxide with the polar solvent, which is a protic solvent.

25. The process according to claim 18, wherein the particulate material of step (a) comprises material obtained from 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.

26. The process according to claim 25, wherein the preliminary step (i) is conducted under reducing conditions comprising carbon and/or a reducing gas chosen from hydrogen and carbon monoxide.

27. The process according to claim 25, wherein in the preliminary step (i) the temperature ranges from 350° C. to 500° C.

28. The process according to claim 18, wherein the particulate material of step (a) is obtained 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).

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

30. The process according to claim 18, further comprising (f) recovering the transition metals nickel and/or cobalt by pyrometallurgical or hydro-metallurgical treatment of the solid residue obtained after carrying out step (c).

31. The process according to claim 29, further comprising (f) recovering the transition metals nickel and/or cobalt by pyrometallurgical or hydro-metallurgical treatment of the solid residue obtained after carrying out step (d).

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

33. A solid produced by the process of claim 18, wherein the solid at of step (c) comprises calcium, lithium, and at least one of Ni, Co, and Mn, wherein at least a fraction of the Ni and/or Co, if present, are present in metallic state and at least a fraction of the Mn, if present, is manganese(II)oxide, and wherein a weight ratio of (Ni+Co+Mn):Li in the solid is about 30:100000, and the solid comprises, by weight of the dry solid, from 2% to 35% of calcium.

34. A lithium hydroxide product, produced by the process according to claim 18, wherein the liquid separated in step (c) is crystallized to form the lithium hydroxide product and wherein the lithium hydroxide product comprises: lithium hydroxide monohydrate comprising 100 ppm to 1.29% of calcium, 0.1% to 1.29% of fluorine, 0.1% to 1.29% of sodium; or anhydrous lithium hydroxide comprising 175 ppm to 2.26% of calcium, 0.175% to 2.26% of fluorine, 0.175% to 2.26% of sodium, wherein all amounts are by weight of the dry solid.

35. A lithium hydroxide product produced the by the process of claim 18, wherein the liquid separated in step (c) is crystallized to form the lithium hydroxide product and wherein the lithium hydroxide product comprises: lithium hydroxide monohydrate comprising 100 ppm to 1.29% of calcium, 0.1% to 1.29% of fluorine, 0.1% to 1.29% of sodium, 20 ppm to 1.29% of zinc, 50 ppm to 1.29% of aluminum, 0.1% to 1.29% of potassium, 0.1 to 1.29% of chlorine; or anhydrous lithium hydroxide comprising 175 ppm to 2.26% of calcium, 0.175% to 2.26% of fluorine, 0.175% to 2.26% of sodium, 35 ppm to 2.26% of zinc, 87 ppm to 2.26% of aluminum, 0.175% to 2.26% of potassium, 0.175 to 2.26% of chlorine, wherein all amounts are by weight of the dry solid.

Description

EXAMPLE 1: SYNTHETIC EDUCT SAMPLE

[0219] An amount of 200 g simulated spent battery scrap containing

[0220] 78.8 g spent cathode active material containing nickel, cobalt and manganese in similar molar amounts, approximate formula Li(Ni0.34Co0.33Mn0.33)O2,

[0221] 62.2 of organic carbon in the form of graphite and soot

[0222] 47.0 g of organic electrolyte mixture (containing LiPF6)

[0223] 7.4 g polyvinylidene fluoride as binder,

[0224] 2.4 g aluminum powder,

[0225] 0.2 g iron powder,

[0226] 2.0 g copper metal

[0227] is placed into a 500-mL quartz round bottom flask and attached to a rotary evaporator in a way that the flask was immersed in an oven. Within 4.5 hours the rotating flask was heated to 800° C. in the course of 2 hours under a flow of argon (20 l/h) and held at this temperature for 1 hour un-der a flow of dry air (20 l/h) before cooling down to ambient temperature. An amount of 173.3 g heat treat material was obtained comprising a phase composition of Ni/Co-alloy, iron manganese oxide, Li2CO3, LiF, and graphite.

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

[0228] An amount of ˜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.

[0229] 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, 2: Mo Ka radiation, FIGS. 3, 4: Cu Ka radiation), elemental analysis (Tab. 2) and particle size distribution (Tab. 3).

[0230] 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.

[0231] 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.

[0232] 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 2.6 g [i.e. 0.14 mol]/100 g (ionic F thereof) (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

[0233] An amount of 5 g of the above-mentioned reduced battery scrap material (obtained as shown in Example 1a) is filled an a PFA flask and mixed with 5, 1.5, 1.0 and 0.5 g of solid Ca(OH)2, respec-tively. 200 g of water are added with stirring, and the whole mixture is refluxed for 4 hours.

[0234] 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

[0235] Example 2 is repeated except that 5 g of the black powder obtained as shown in Example 1a, 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

[0236] An amount of 10, 20 and 30 g, respectively, of the particulate material (PM) described in example 1a 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.

[0237] 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 material Lithium Fluoride 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

[0238] Following the procedure of Example 2a, solid Ca(OH)2 and the particulate material (PM) described in example 1a 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 Sample t [h] Li [%] F.sup.− [%] Li [%] 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

[0239] 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 Cl and minor impurities (<200 ppm) of Al and Zn.

BRIEF DESCRIPTION OF FIGURES

[0240] FIG. 1: X-ray powder diffractogram (Mo Ka) of reduced mass from waste lithium ion batteries after heat/reduction treatment as obtained in example 1a and used in example 2a including reference diffractograms of graphite, cobalt, manganese-II-oxide, cobalt oxide, and nickel.

[0241] FIG. 2: X-ray powder diffractogram (Mo Ka) of reduced mass from waste lithium ion batteries after heat/reduction treatment as obtained in example 1a and used in example 2a including reference diffractograms of graphite, lithium aluminate, and lithium carbonate.

[0242] FIG. 3: X-ray powder diffractogram (Cu Ka) of reduced mass from waste lithium ion batteries after heat/reduction treatment as obtained in example 1a and used in example 2a including reference diffractograms of graphite, cobalt, manganese-II-oxide, cobalt oxide, and nickel.

[0243] FIG. 4: X-ray powder diffractogram (Cu Ka) of reduced mass from waste lithium ion batteries after heat/reduction treatment as obtained in example 1a and used in example 2a including reference diffractograms of graphite, lithium aluminate, and lithium carbonate.

[0244] FIG. 5: X-ray powder diffractogram (Cu Ka) of LiOH monohydrate as obtained in example 5.