Method and system for supercritical fluid extraction of metal
A method for supercritical fluid extraction of metal from a source, the method comprising: providing a reactor chamber; providing a source comprising a target metal; optionally, providing a chelating agent; providing a solvent; adding the source comprising the target metal, the chelating agent and the solvent into the reactor chamber; adjusting the temperature and pressure in the reactor chamber so that the solvent is heated and compressed above its critical temperature and pressure; optionally, providing mechanical agitation to the reactor chamber; recovering a chelate comprising the target metal.
1 . A method for supercritical fluid extraction of at least one target metal from a source, the method comprising:
providing a reactor chamber;
providing a source selected from the group consisting of a battery, a permanent magnet, a bauxite residue, and an activated carbon, the source comprising:
the at least one target metal, being chemically bonded to at least one additional metal via metallic bonds; and
at least one impurity;
pre-processing the source;
providing a chelating agent being one or more compounds selected from the group consisting of an organophosphorus compound, a ketone, a dithiocarbamate, a crown ether, a fluorinated compound, 8-hydroxyquinoline, 7-(1-vinyl-3,3,5,5-tetramethylhexyl)-8-hydroxyquinoline, an amide, an organic acid, a quaternary ammonium salt, and an oxime;
providing a solvent;
providing a co-solvent;
adding the pre-processed source the chelating agent, the solvent and the co-solvent into the reactor chamber;
adjusting the temperature in the reactor chamber to a range of about 35 to about 55° C. and the pressure in the reactor chamber so that the solvent is heated and compressed above its critical temperature and pressure;
optionally, providing mechanical agitation to the reactor chamber; and
recovering a chelate comprising the target metal,
wherein:
the organophosphorus compound is selected from the group consisting of tributyl phosphate (TBP), tributyl phosphate-nitric acid (TBP-HNO 3 ), trialkylphosphine oxide-nitric acid (TRPO-HNO 3 ), tributylphosphine oxide (TBPO), trioctylphosphine oxide (TOPO), triphenylphosphine oxide (TPPO), bis(2-ethylhexyl) phosphate (DEHPA), bis(2-ethylhexyl)monothiophosphoric acid (D2EHTPA), dialkyl phosphinic acid (Cyanex 272), bis(2,4,4-trimethylpentyl)dithiophosphinic acid (Cyanex 301, Cyanex 302), bis-(2-ethylhexyl)phosphoric acid (B 2 EHPA), carbamoylmethylene phosphine oxide (CMPO), 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC88A), phosphonoacetic acid (PAA) and N,N-bisphosphono(methyl)glycine (BPG);
the ketone is selected from the group consisting of acetylacetone (AA), trifluoroacetylacetone (TFA), hexafluoroacetylacetone (HFA), trifluoroacetylacetone (TAA), thenoyltrifluoroacetone (TTA), methyl isobutyl ketone (MIBK), 2,2,7-trimethyl-3,5-octanedione (TOD), 2,2,6,6-tetramethyl-3,5-heptanedione (THD), 1,1-dimethyl-3,5-hexanedione (DMHD), 2,6-dimethyl-3,5-heptanedione (DIBM), 1,1,1-trifluoro-4-phenyl-2,5-butanedione (TFBZM) and 1-phenyl-1,3-pentanedione (BZAC);
the dithiocarbamate is selected from the group consisting of lithium bis(trifluoroethyl)dithiocarbamate (LiFDDC), diethyldithiocarbamate (DDC), bis(trifluoroethyl)dithiocarbamate (FDDC), dipropyldithiocarbamate (P3DC), dibutyldithiocarbamate (BDC), dipentyldithiocarbamate (P5DC), dihexyldithiocarbamate (HDC), pyrrolidinedithiocarbamate (PDC) and tetrabutylammonium dibutyldithiocarbamate TBA (BDC);
the crown ether is selected from the group consisting of 2,2-dicyclohexyl-1,4,7,10,13,16,19-heptaoxacyclohenicosane (DCH21C7), 2,3,11,12-dicyclohexano-1,4,7,10,13,16-hexaoxacyclooctadecane (DCH18C6), 1,4,7,10,13-pentaoxacyclopentadecane (15C5), bistriazolo-crown ether I (Crown I), bistriazolo-crown ether II (Crown II) and bistriazolo-crown ether III (Crown III);
the fluorinated compound is selected from the group consisting of 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-oactanedione (HFOD), 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (HFAC), thenoyltrifluoroacetone (TTFA), pentadecafluorooactanoic acid (HPFOA), ammonium perfluoropolyether piperazindithiocarbamate (FE-APDC), perfluoropolyether picolylamine (FE-PA), ammonium perfluoropolyether dithiocarbamate (FE-DC), perfluoropolyether dithiol (FE-DT) and heptafluorobutanoylpivaroylmethane (FOD);
the organic acid is selected from the group consisting of neodecanoic acid, diethylenetriaminepentaacetic acid (DTPA), diethylenetriaminepentaacetic dianhydride (DTPA-DA) and triethylenetetraaminehexaacetic acid (H 6 TTHA);
the amide is selected from the group consisting of N,N,N′,N′-tetraoctyldiglycolamide (TODGA), N,N,N′,N′-tetraisobutyl-3-oxapentanediamide (TiBODA), N,N,N′,N′-tetrabutyl-3-oxapentanediamide (TBODA) and N,N′-dimethyl-N,N′-dibutyltetradecylmalonamide (DMDBTDMADBBP);
the quaternary ammonium salt is N-methyl-N,N,N-trioctylammonium chloride; and
the oxime is 2-hydroxy-5-nonylbenzophenone oxime.
2 . The method of claim 1 , wherein the solvent is one or more compounds selected from the group consisting of CO 2 , water, methanol, ethanol, benzene, and toluene.
3 . The method of claim 1 , wherein the co-solvent is one or more compounds selected from the group consisting of methanol, water, ethanol, acetone, hexane, chloroform, dichloromethane, toluene, acetonitrile, tetrahydrofuran, aniline, diethylamine, acetic acid, ethyl acetate, 2-propanol, and an imidazolium-based ionic compound.
4 . The method of claim 1 , wherein the source is a NiMH battery or a permanent magnet, and the target metal is one or more rare earth elements.
5 . The method of claim 4 , wherein:
the pressure in the reactor chamber is adjusted to a range of about 20.7 to about 31 MPa;
the source comprising the target metal, the chelating agent, the solvent and the co-solvent are allowed to react in the reactor chamber for a residence time in a range of about 1 to about 2 hours;
the source comprising the target metal and the chelating agent are added in a source-to-chelating agent ratio in the range of about 0.1 to about 0.2 g/mL;
the method comprises providing mechanical agitation to the reactor chamber and the source comprising the target metal, the chelating agent, the solvent and the co-solvent are subjected to an agitation rate in a range of about 750 to about 1500 rpm;
the chelating agent comprises HNO 3 in a concentration of about 10.4 to about 15.7 M; and
the co-solvent is methanol and is added into the reactor chamber in an amount of about 0.01 to about 2 mol %.
6 . The method of claim 1 , wherein the source is a bauxite residue, and the target metal is one or more rare earth elements.
7 . The method of claim 6 , wherein:
the pressure in the reactor chamber is adjusted to a range of about 20.7 to about 45 MPa;
the source comprising the target metal, the chelating agent, the solvent and the co-solvent are allowed to react in the reactor chamber for a residence time in a range of about 0.01 to about 2.0 hours;
the source comprising the target metal and the chelating agent are added in a source-to-chelating agent ratio in the range of about 0.05 to about 0.2 g/mL;
the method comprises providing mechanical agitation to the reactor chamber and the source comprising the target metal, the chelating agent, the solvent and the co-solvent are subjected to an agitation rate in a range of about 1500 to about 2500 rpm;
the chelating agent comprises HNO 3 in a concentration of about 15.7 to about 21.4 M;
the co-solvent is added into the reactor chamber in an amount of about 0.01 to about 10 mol %;
the chelating agent is selected from the group consisting of tributyl phosphate (TBP), bis(2-ethylhexyl) phosphate (DEHPA), mono-(2-ethylhexyl)-2-ethylhexyl-phosphate (HEHEHP), bis(2,4,4-trimethylpentyl)phosphinic acid, bis(2,4,4-trimethylpentyl)dithiophosphinic acid, bis(2,4,4-trimethylpentyl)octylphosphine oxide, neodecanoic acid and 16,16-dimethylheptadecan-1-amine; and
the chelating agent comprises an acid selected from the group consisting of nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, hydrofluoric acid, citric acid, acetic acid and oxalic acid.
8 . The method of claim 7 , wherein the co-solvent is methanol or oxalic acid solution in water.
9 . The method of claim 1 , wherein the source is a lithium ion battery, and the target metal is selected from the group consisting of lithium, nickel, and cobalt.
10 . The method of claim 9 , wherein:
the pressure in the reactor chamber is adjusted to a range of about 20 to about 45 MPa;
the source comprising the target metal, the chelating agent, the solvent and the co-solvent are allowed to react in the reactor chamber for a residence time in a range of about 0.01 to about 2 hours;
the source comprising the target metal and the chelating agent are added in a source-to-chelating agent ratio in the range of about 0.01 to about 2 g/mL;
the method comprises providing mechanical agitation to the reactor chamber and the source comprising the target metal, the chelating agent and the solvent are subjected to an agitation rate in a range of about 750 to about 2500 rpm;
the chelating agent comprises HNO 3 in a concentration of about 0.01 to about 21.4 M;
the co-solvent is added into the reactor chamber in an amount of about 0.01 to about 5 mol %; and
the chelating agent is selected from the group consisting of crown ethers, tributyl phosphate (TBP), bis(2-ethylhexyl) phosphate (DEHPA), mono-(2-ethylhexyl)-2-ethylhexyl-phosphate (HEHEHP), bis(2,4,4-trimethylpentyl)phosphinic acid, bis(2,4,4-trimethylpentyl)dithiophosphinic acid, bis(2,4,4-trimethylpentyl)octylphosphine oxide, neodecanoic acid and 16,16-dimethylheptadecan-1-amine.
11 . The method of claim 10 , wherein the co-solvent is selected from the group consisting of methanol, anhydrous acetonitrile (ACN), diethyl carbonate (DEC), and propylene carbonate (PC).
12 . The method of claim 9 , wherein the pre-processing of the source comprises a first extraction phase to extract organic components from the lithium ion battery and a second extraction phase to extract the target metal, wherein the first extraction phase and the second extraction phase take place under the same or different reaction conditions.
13 . The method of claim 1 , wherein the co-solvent is added to the reactor chamber in an amount of about 0.01 to about 50 mol % relative to the total number of moles of solvent.
14 . The method of claim 1 , wherein the pressure in the reactor chamber is adjusted to a range of about 0.01 to about 45 MPa.
15 . The method of claim 1 , wherein the source comprising the target metal, the chelating agent and the solvent are allowed to react in the reactor chamber for a residence time in a range of about 0.01 to about 12 hours.
16 . The method of claim 1 , wherein the source comprising the target metal and the chelating agent are added in a source-to-chelating agent ratio in the range of about 0.01 to about 5 weight (g) per volume (mL).
17 . The method of claim 1 , wherein the method comprises providing mechanical agitation to the reactor chamber and the source comprising the target metal, the chelating agent and the solvent are subjected to an agitation rate in a range of about 0.01 to about 2500 rpm.
18 . The method of claim 1 , wherein the chelating agent comprises HNO 3 in a concentration of about 0.01 to about 21.4 M.
19 . The method of claim 1 , wherein the source is a secondary waste feed.
20 . The method of claim 1 , wherein the chelating agent comprises tributyl phosphate-nitric acid (TBP-HNO 3 ).