DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Specification
The disclosure is objected to because of the following informalities: the instant specification recites “3-n cycles, … wherein 3<n≤15.” This language recites a range within a range; it is unclear how this is different from 3-15 cycles. Appropriate correction is required.
Claim Interpretation
Claim 1 recites “the lithium iron phosphate waste,” which lacks antecedent basis. To proceed with further examination, the broadest reasonable interpretation will be used of the filtrate containing Li+ and/or Fe3+ being mixed with either more amounts of the original lithium iron phosphate solid waste or with any amount of the slurry obtained from step (1).
Claim 1 additionally recites a “multi-stage counter-current circulation leaching” process, in step (4), which is not defined in the instant disclosure. This process is supported by the upwards arrow in the sole figure. As such, the broadest reasonable interpretation of such a process will be applied, in which the solution containing Li+, Fe3+ is recycled into the first step, where another completion of the claimed method may be performed.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-16 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites the limitation "mixing the filtrate... with the lithium iron phosphate waste" in step (4). The lithium iron phosphate (LiFePO4) waste recited earlier in claim 1 is transformed in identity through steps (2) to (4), first transforming into a slurry, then a filtrate/slag product, then another filtrate. Step (4) requires mixing the filtrate from step (3) with the original LiFePO4 waste, which renders unclear the interaction between the filtrate with the LiFePO4 waste, as it is unclear whether the filtrate should be mixed with the LiFePO4 waste-containing slurry of step (1) or if the filtrate is mixed with a second LiFePO4 waste, since the LiFePO4 waste of step (1) is mixed with water immediately, in the instant claim. Claim 1 is therefore indefinite in the scope of to what material the filtrate of step (4) should be added. Claims 2-16 depend on, or otherwise incorporate the limitations of, claim 1 and do not rectify the issue of indefiniteness, and are therefore similarly rejected.
Claim 2 additionally recites a “solid-to-liquid ratio of (3-10):1” between a solid and a liquid of separate identities and does not recite units of either mass or volume. This is not a meaningful term of the art: a ratio of grams-to-liters is not interchangeable with a ratio of grams-to-milliliters, for example. It would not be possible for one of ordinary skill in the art to determine whether a given ratio meets the limits of the instant claim. The instant specification provides Examples 1-5 and Comparative Example 1 wherein the liquid-to-solid ratio, rather than the solid-to-liquid ratio, of water to LiFePO4 waste ranges from (3-10) mL : 1 g; this interpretation will be applied to claim 2 to proceed with further examination.
Claim 7 additionally recites “3 – n cycles,” which is interpreted to mean “3 to n cycles,” and further recites “wherein 3<n≤15.” The current language recites a range within a range, which is redundant, and it is unclear whether this is the intended scope of the claim. To proceed with further examination, the interpretation of the multi-stage counter-current leaching process being performed for 3-15 cycles will be used.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-5, 7-13, and 15-16 are rejected under 35 U.S.C. 103 as being unpatentable over Dai et al. (CN 110474123 A) in view of Xu et al. (CN 208493380 U), referred to herein as Dai and Xu, respectively. Machine translations of both documents, as provided with this office action, are cited herein.
Regarding claim 1, Dai teaches a method for recovering lithium from lithium iron phosphate waste (0060) comprising adding waste LiFePO4 battery cathode material to a trivalent iron salt in solution form (step 1, 0032), such a solution necessarily containing water. This meets the limitations of (1) adding water to the lithium iron phosphate waste to obtain a lithium iron phosphate slurry; and (2) adding a soluble iron salt to the lithium iron phosphate slurry to perform a reaction. It is noted that the courts have ruled that adding ingredients in a different order is prima facie obvious without evidence of criticality; In re Gibson, 39 F.2d 975, 5 USPQ 230 (CCPA 1930) (see MPEP 2144.04; Selection of any order of mixing ingredients is prima facie obvious.).
Dai further teaches filtering a resulting product to obtain an iron phosphate slag and a filtrate (0032) containing Li+, Fe2+ (0037) ; (3) adding an oxidizing agent to the filtrate containing Li+, Fe2+ to perform a reaction, and filtering to obtain iron hydroxide and a filtrate containing Li+,Fe3+ (step 2, 0044, 0045, filtered, 0051). Dai teaches a molar amount of iron in the soluble iron salt in step (2) is 1 : 1 to a molar amount of iron in the lithium iron phosphate slurry (0038). While 1 falls just outside the range of 1.1 to 1.3, generally, the courts have held that differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." See MPEP 2144.05 and In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the molar amount of iron from the soluble iron salt added to the slurry within a reasonable range near the disclosed ratio of 1:1, and arrive at an amount that falls within the instant claimed range of 1.1 to 1.3 times the molar amount of iron in the lithium iron phosphate slurry.
Dai does not teach step (4) mixing the filtrate containing Li+ , Fe3+ with the lithium iron phosphate waste to obtain a mixture, and does not teach subjecting the mixture to a multi-stage counter-current circulation leaching process to obtain a lithium solution. Dai does teach that the method is a circulation process (closed-loop circulation system, 0024).
However Xu teaches a method for preparing a solution containing lithium ions (0007) wherein Example 1 comprises a three-stage countercurrent leaching process (0118). Xu further teaches that the filtrate of the secondary countercurrent leaching step is mixed with the lithium-containing solid raw materials in order to obtain a tertiary leachate which is the solution containing lithium ions (0127, Figure 2). Xu teaches that this solution is further processed with hydroxide in order to remove iron impurities (0133, 0135), which necessarily requires that the Fe3+ is present in the secondary leachate. The mixture of secondary leachate and the lithium solid raw materials is then subjected to the multi-stage countercurrent leaching process taught by Xu (Figure 2). This meets the requirements of mixing the filtrate containing Li+, Fe3+ with lithium solid and subjecting the mixture to multi-stage countercurrent leaching to obtain a lithium solution as required by the instant claim.
It would be obvious to one skilled in the art before the effective filing date of the invention to modify the circulation leaching process taught by Dai to be a multi-stage countercurrent leaching process, as taught by Xu. One skilled in the art would be motivated to do so in order to obtain a high concentration lithium solution, instead of solid lithium carbonate, as taught by Xu (0006). Therefore one skilled in the art would reasonably be motivated to modify the method taught by Dai with the multi-stage counter-current circulation leaching steps taught by Xu, thus arriving at the claimed invention with reasonable prediction of success.
Regarding claim 2, Dai teaches a solid-to-liquid ratio of (40g-500g):1L (0040), which yields a liquid-to-solid ratio of 2-25 mL:1 g. Example 4 teaches 1.125 M with 300 g LiFePO4 which yields a liquid-to-solid ratio of 3 mL:1 g; see below for calculations.
1.125
m
o
l
L
F
e
2
S
O
4
3
*
400
g
m
o
l
=
450
g
L
F
e
2
S
O
4
3
450
g
L
*
1
m
L
3.09
g
F
e
2
S
O
4
3
≈
150
m
L
L
F
e
2
S
O
4
3
1000
m
l
s
o
l
u
t
i
o
n
-
150
m
l
F
e
2
S
O
4
3
=
850
m
L
H
2
O
850
m
L
:
300
g
L
i
F
e
P
O
4
=
2.83
:
1
≈
3
:
1
Regarding claim 3, Dai teaches ferric sulfate solution, ferric chloride solution, and ferric nitrate solution, 0041.
Regarding claim 4, Dai teaches the reaction temperature is 25-70℃, the reaction time is 23-60 min, 0038. As set forth in MPEP 2144.05, in the case where the claimed range "overlap or lie inside ranges disclosed by the prior art", a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. 1990). It would have been obvious to one of ordinary skill in the art at the time of filing of the invention to perform a method for recovering lithium as suggested by Dai and Xu where the temperature of the reaction is in any workable or optimum range overlapping with 25-70°C as taught by Dai, including the claimed range, in order to obtain a temperature suitable for the reaction. Similarly, it would have been obvious to one of ordinary skill in the art at the time of filing of the invention to perform a method for recovering lithium as suggested by Dai and Xu where the length of the reaction is in any workable or optimum range overlapping with 23-60 min as taught by Dai, including the claimed range, in order to obtain a duration suitable for the reaction.
Regarding claim 5, Dai teaches hydrogen peroxide, oxygen, air, and ozone, 0049.
Regarding claim 7, in Dai modified by Xu, Xu teaches three-stage countercurrent leaching, 0018, which falls within the instant claimed range of 3 to 15, as interpreted above. Xu additionally teaches that the invention recovers lithium in solution with 94% content (0054), which must necessarily have an iron content of no more than 6%. As the purity of lithium and iron in solution is a variable that can be modified, among others, by adjusting the number of leaching cycles, with the mass content of lithium increasing as the number of cycles is increased which decreases the mass content of iron, the precise mass content of iron in the lithium solution would have been considered a result effective variable by one having ordinary skill in the art before the effective filing date of the invention. As such, without showing unexpected results, the claimed mass content cannot be considered critical. Accordingly, one of ordinary skill in the art before the effective filing date of the invention would have optimized, by routine experimentation, the mass content in Xu to a range over the range of 6% or less taught by Xu, including the claimed range of 0.5% or less, to obtain the desired balance between the number of leaching cycles and the content of iron compared to the economic cost, as taught by Xu (0067) (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223). “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.).
Regarding claim 8, in Dai modified by Xu, Xu teaches that the leaching process is performed at 60 to 80 degrees Celsius, 0016. Dai additionally teaches an embodiment of the method disclosed that obtains a lithium purity of 99.03% in the final solution (0089).
Regarding claim 9, Dai teaches that the method is used to recycle waste lithium iron phosphate batteries (title).
Regarding claim 10, Dai teaches that the method is used to recycle waste lithium iron phosphate batteries (title).
Regarding claim 11, Dai teaches that the method is used to recycle waste lithium iron phosphate batteries (title).
Regarding claim 12, Dai teaches that the method is used to recycle waste lithium iron phosphate batteries (title).
Regarding claim 13, Dai teaches that the method is used to recycle waste lithium iron phosphate batteries (title).
Regarding claim 15, Dai teaches that the method is used to recycle waste lithium iron phosphate batteries (title).
Regarding claim 16, Dai teaches that the method is used to recycle waste lithium iron phosphate batteries (title).
Claims 6 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Dai and Xu, as applied to claim 1 above, and in further view of Hu et al. (CN 108899601 A), referred to herein as Hu. The English translation as provided with this office action is cited herein.
Regarding claim 6, Dai modified by Xu teaches the method as applied to claim 1 above.
Dai and Xu do not teach the reaction being carried out at a temperature of 50 C-80 C for 30-80 min.
However, Hu teaches a method for recovering lithium from lithium iron phosphate (0000) wherein the oxidation step (step 2) is conducted for 50-70 min (0020) and is conducted at the same conditions as the previous step, which is at a reaction temperature of 10-60 degrees C (0019).
It would be obvious to one of ordinary skill in the art before the effective filing date of the present invention to modify the invention taught by Dai and Xu with the reaction conditions taught by Hu. One skilled in the art would be motivated to do so because the conditions taught by Hu allow one skilled in the art to convert iron and phosphate ions into water-insoluble compounds while allowing lithium to be in a water-soluble form, as taught by Hu (0005). While the temperature range of 10-60 degrees C taught by Hu overlaps with the range of 40-80 degrees C required by the instant claim, as set forth in MPEP 2144.05, in the case where the claimed range "overlap or lie inside ranges disclosed by the prior art", a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. 1990). It would have been obvious to one of ordinary skill in the art at the time of filing of the invention to perform a method for preparing lithium as taught by Dai and Xu where the temperature of the oxidation step is in any workable or optimum range overlapping with 10-60 degrees C as taught by Hu, including the claimed range, in order to obtain a temperature suitable for the reaction, and thus arrive at the claimed invention with reasonable prediction of success.
Regarding claim 14, Dai teaches that the method is used to recycle waste lithium iron phosphate batteries (title).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Hu, Tian, and Wang, CN 1088899601 A, disclose a method for recycling lithium from the lithium iron phosphate, the method comprising (1) adding water to the lithium iron phosphate waste to obtain a lithium iron phosphate slurry (step 1) : (2) adding a soluble iron salt to the lithium iron phosphate slurry to perform a reaction (step 1) , and filtering a resulting product to obtain an iron phosphate slag and a filtrate containing Li+, Fe2+ (step 1) ;(3) adding an oxidizing agent to the filtrate containing Lie, Fe2+ to perform a reaction, and filtering to obtain iron hydroxide and a filtrate containing Li+,Fe3+ (step 2); (4) mixing the filtrate containing Li+,Fe3+ with the lithium iron phosphate waste to obtain a mixture, wherein the oxidant may be hydrogen peroxide, oxygen or ozone, with a recovery rate of lithium of 97.5%.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Eileen Moudou whose telephone number is (571)272-1768. The examiner can normally be reached M-Th 8 AM - 4 PM EST.
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/Eileen Moudou/ Examiner, Art Unit 1738
/MICHAEL FORREST/ Primary Examiner, Art Unit 1738