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 .
Response to Amendment
The Amendment filed 15 April 2026 has been entered. Claims 12-15 and 17-20 are amended; claims 21-32 are added. Accordingly, claims 12-15 and 17-32 remain pending in the application.
Specification
The disclosure is objected to because of the following informalities:
In [0035], "lithium, concentration" should read "lithium concentration".
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim 27 is rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 27, lines 2-4, recite "one or more of the second crystallization step or the third crystallization step comprises removing water vapor and non-condensable gases by ejector or barometric condenser trains cooled by water from a cooling tower". However, the specification of the present application only teaches cooling by water from a cooling tower for the second crystallization step [0024], [0043]. In regards to the third crystallization step, cooling is done by chilled water [0026], [0045], not by water from a cooling tower.
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 14-15, 21-23, and 28 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 14, lines 2-3, recite "the caustic material is milk-of-lime to adjust a pH to approximately 11". It is unclear what is adjusting the pH to approximately 11. It is further unclear what material's pH is being adjusted. This limitation is interpreted as requiring wherein the addition of the caustic material adjusts the pH of the neutralized filtrate to approximately 11, and wherein the caustic material is milk-of-lime.
Claim 21, line 2, recites "washing the neutralized filtrate". It is unclear what "neutralized filtrate" this step would be using. Per [0038]-[0039] of the specification and Fig. 3 of the present application, this limitation is interpreted as requiring washing the neutralized filtrate after precipitating remaining impurities via addition of a caustic material.
Claim 23, line 2, recites "separating the neutralized filtrate". It is unclear what "neutralized filtrate" this step would be using. Per [0038]-[0039] of the specification and Fig. 3 of the present application, this limitation is interpreted as requiring separating the neutralized filtrate after precipitating remaining impurities via addition of a caustic material.
Claim 28 recites the limitation "the glycol-water mixture" in line 2. There is insufficient antecedent basis for this limitation in the claim. This limitation is interpreted as being dependent on claim 19.
Claims 15 and 22 are indefinite as they depend from an indefinite base and fail to cure the deficiencies of the base claim.
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.
Claims 12, 21-24, 26, and 30 are rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860).
Regarding Claim 12, Fang discloses a method for separating calcium and magnesium from a calcium-magnesium leaching solution of chemical ore dressing byproduct (separating calcium and magnesium from a calcium-magnesium leaching solution of chemical ore dressing byproduct meets the limitation of reducing alkaline earth metals in solids, as calcium and magnesium are alkaline earth metals, and ore meets the limitation of solids; pg. 8, paragraph 3), wherein the calcium-containing magnesium leaching liquid can be obtained by taking low-grade phosphorite as raw material (low-grade phosphorite is the ore of the ore dressing byproduct, and meets the limitation of solids), crushing, calcining, leaching, and filtering; the liquid discharged from the filter press is the calcium-containing magnesium leaching liquid (leaching phosphorite meets the limitation of acid-leaching the solids; pg. 4, par. 12-pg. 5, par. 1). Fang further discloses a decalcification reaction of the leaching liquid with crude nitrate calcium liquid and potassium sulphate to produce a slurry, and solid-liquid separation of the slurry to obtain a decalcified liquid and calcium sulphate (decalcified liquid meets the limitation of an effluent slurry; claim 1); neutralizing the decalcified liquid to form a neutralized liquid (neutralizing the decalcified liquid meets the limitation of neutralizing the effluent slurry to form a neutralized filtrate; claim 1); concentrating the neutralized liquid by evaporation in a forced circulation type evaporator (pg. 8, paragraph 1); wherein concentrating the neutralized liquid takes place prior to crystallization (pg. 3, par. 6); crystallizing potassium nitrate from the neutralized liquid in a crystallization step (potassium nitrate appears to meet the limitation of impurities; claim 1); and carrying out a magnesium removing reaction to obtain magnesium hydroxide (a magnesium removing reaction to obtain magnesium hydroxide meets the limitation of precipitating remaining impurities; claim 1).
Fang is silent to the solids containing lithium.
Fang, however, discloses the calcium-containing magnesium leaching liquid can be obtained by taking low-grade phosphorite as raw material (pg. 4, par. 12-pg. 5, par. 1), such that the calcium-containing magnesium leaching liquid is not particularly limited.
Fan discloses a process for extracting lithium hydroxide from lithium phosphate rock (lithium phosphate rock meets the limitation of lithium-containing solids; [0001]) comprising acid-leaching ([0015], [0017]), neutralizing the acid in the solution [0033], concentrating by evaporation [0019] and crystallization [0022], wherein calcium and magnesium impurities are removed (removing magnesium impurities meets the limitation of reducing alkaline earth metals; [0096]), such that the leaching liquid of Fan contains calcium and magnesium (as required by Fang). Fan further discloses lithium phosphate is a lithium and aluminum fluorophosphate that occurs in granite pegmatites, often found alongside spodumene, tourmaline, lepidolite, and apatite [0007].
Omelon discloses geological phosphorite is composed essentially of carbonate apatites which are usually moderately high in fluorine (pg. 384, Col. 2, par. 5).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Fan and Omelon wherein the solids are lithium-containing, because the ore of Fang is not particularly limited, and the phosphorite ore of Fang is similar to the lithium phosphate of Fan as both are ores containing phosphorous, fluorine, calcium, and magnesium, as recognized by Fang (pg. 4, par. 12-pg. 5, par. 1), Fan [0007] and Omelon (pg. 384, Col. 2, par. 5) and lithium phosphate is often found alongside apatite, as recognized by Fan [0007], wherein apatites are a component of phosphorite, as recognized by Omelon (pg. 384, Col. 2, par. 5).
Fang is further silent to concentrating the neutralized filtrate by Mechanical Vapor Recompression heating falling film evaporators.
Fang, however, teaches concentrating the neutralized liquid by evaporation in a forced circulation type evaporator (pg. 8, paragraph 1).
Worsley discloses concentrating via evaporation (claim 1) by falling film MVR evaporators (falling film MVR evaporator meets the limitation of Mechanical Vapor Recompression heated falling film evaporator; claim 19, [0033]), which are evaporators known to have high rate of heat transfer and high energy efficiency (claim 19).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Worsley to concentrate the neutralized filtrate by Mechanical Vapor Recompression heated falling film evaporators in order to evaporate with a high rate of heat transfer and high energy efficiency, as recognized by Worsley (claim 19).
Fang is further silent to holding a lithium concentration in the neutralized filtrate below a lithium target concentration to avoid crystallizing a lithium-potassium double salt when the neutralized filtrate leaves the Mechanical Vapor Recompression heated falling film evaporator.
Fang, however, discloses concentrating a neutralized liquid by evaporation in a forced circulation type evaporator (pg. 8, paragraph 1).
Nishikawa discloses a method for recovering lithium from a lithium-ion secondary battery (lithium-ion secondary battery meets the limitation of solids) comprising: a lithium leaching step, a membrane separation step, and a calcium removal step (calcium removal meets the limitation of reducing alkaline earth metals; [0011]). Nishikawa further discloses by setting the lithium concentration of the first lithium concentrated solution to less than 4,000 mg/L, it is possible to prevent crystallization (preventing crystallization of lithium necessarily prevents the crystallization of a lithium-potassium double salt) and clogging of lithium carbonate on the membrane surface during membrane separation, and it becomes possible to perform continuous, stable membrane separation over a long period of time [0038] and allows for later recovery of a high-purity lithium salt [0014].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Nishikawa to hold a lithium concentration in the neutralized filtrate below a lithium target concentration to avoid crystallizing a lithium-potassium double salt when the neutralized filtrate leaves the Mechanical Vapor Recompression heated falling film evaporator in order to recover a high-purity lithium salt after removing alkaline earth metal impurities, as recognized by Nishikawa [0014].
Fang is further silent to crystallizing impurities from the neutralized filtrate in a first crystallization step in a forced circulation crystallizing step; crystallizing impurities from the neutralized filtrate in a second crystallization step in a first draft tube crystallizing step; crystallizing impurities from the neutralized filtrate in a third crystallization step in a second draft tube crystallizing step.
Fang, however, teaches crystallizing potassium nitrate from the neutralized liquid in a crystallization step (potassium nitrate appears to meet the limitation of impurities; claim 1).
Wrubel discloses crystallizing potassium nitrate (the impurity crystallized in Fang) [0095], wherein the crystallizer is a forced circulation crystallizer, draft tube baffle crystallizer, or any combination thereof [0064].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Wrubel to crystallize impurities from the neutralized filtrate in a first crystallization step in a forced circulation crystallizing step; crystallize impurities from the neutralized filtrate in a second crystallization step in a first draft tube crystallizing step; crystallize impurities from the neutralized filtrate in a third crystallization step in a second draft tube crystallizing step, because crystallizing in multiple steps is a process parameter well-known in the art of crystallization, as taught by Wrubel, in order to further improve the removal of impurities (i.e. potassium nitrate), absent a showing of unexpected results through routine experimentation (MPEP 2144.04 IV B).
Fang is further silent to precipitating remaining impurities via addition of a caustic material.
Fang, however, teaches carrying out a magnesium removing reaction to obtain magnesium hydroxide (a magnesium removing reaction to obtain magnesium hydroxide meets the limitation of precipitating remaining impurities; claim 1).
Hunwick discloses milk of lime (milk of lime meets the limitation of a caustic material) may be added to a blend of potassium, magnesium and lithium with chloride to precipitate the magnesium as insoluble magnesium hydroxide (magnesium hydroxide meets the limitation of an impurity) in order to remove magnesium, which can be a problem when present in high concentrations because both its sulphate and chloride are quite soluble in aqueous solutions [0109].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Hunwick to precipitate remaining impurities via addition of a caustic material in order to remove magnesium, which can be a problem when present in high concentrations because both its sulphate and chloride are quite soluble in aqueous solutions, as recognized by Hunwick [0109].
Regarding Claim 21, Fang discloses washing the neutralized filtrate to obtain a high purity magnesium product (pg. 7, par. 2).
Fang is silent to washing the neutralized filtrate using a brine recovery step to facilitate recovery of lithium.
Hunwick discloses a solids separation to recovery lithium nitrate solids (recovering lithium nitrate meets the limitation of recovery of lithium; [0144]), wherein the solids removal process is counter-current decantation (counter current decantation meets the limitation of washing using a brine recovery step; [0146]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Hunwick to wash the neutralized filtrate using a brine recovery step to facilitate recovery of lithium, because Fang teaches washing to obtain a high purity product (pg. 7, par. 2), and washing using counter-current decantation (aka a brine recovery step) is a process parameter well-known in the art of washing to recover high purity products, as recognized by Hunwick [0146].
Regarding Claim 22, Hunwick discloses a solids separation to recovery lithium nitrate solids (recovering lithium nitrate meets the limitation of recovery of lithium; [0144]), wherein the solids removal process is counter-current decantation (counter current decantation meets the limitation of washing using a brine recovery step; [0146]).
Regarding Claim 23, Fang discloses filtering (filtering meets the limitation of separating the neutralized filtrate) and washing after the magnesium removal reaction to obtain magnesium hydroxide product (magnesium hydroxide product is a solid and therefore meets the limitation of a solids-containing stream) and a de-magnesium liquid (de-magnesium liquid meets the limitation of a liquid-containing stream; pg. 8, par. 7).
Regarding Claim 24, Fang is silent to minimizing an amount of scaling caused by gypsum precipitation when concentrating the neutralized filtrate.
Worsley discloses a reduction in the concentration of calcium and magnesium greatly reduces the potential for scale formation (reducing scale formation meets the limitation of minimizing an amount of scaling) in mechanical evaporations processes used in concentrating brine [0029]. The neutralized filtrate of Fang is calcium-containing (claim 1), and Worsely discloses preventing precipitation of calcium compounds [0029], wherein gypsum is a calcium compound, such that Worsely meets the limitation of scaling caused by gypsum precipitation. Worsley further discloses preventing scaling of heat transfer surfaces [0029], and bringing the brine close to saturation in the evaporator provides a high rate of heat transfer and high energy efficiency (claim 19).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Worsley to minimize an amount of scaling caused by gypsum precipitation when concentrating the neutralized filtrate in order to prevent scaling of heat transfer surfaces, providing a high rate of heat transfer and high energy efficiency, as recognized by Worsley (claim 19).
Regarding Claim 26, Fang discloses after crystallization, centrifuging and separating the crystal (solids) from the crystallized mother liquor (the neutralized filtrate) (pg. 10, par. 1).
Regarding Claim 30, Fang discloses a calcium-magnesium leaching solution of chemical ore dressing byproduct (pg. 8, paragraph 3), wherein the calcium-containing magnesium leaching liquid can be obtained by taking low-grade phosphorite as raw material (low-grade phosphorite is the ore of the ore dressing byproduct, and meets the limitation of an ore; pg. 4, par. 12-pg. 5, par. 1).
Fan discloses a lithium phosphate rock (lithium phosphate rock meets the limitation of an ore; [0001]).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860) and Gu (CN 101724748).
Regarding Claim 13, Fang, Fan, Worsely, Nishikawa, Wrubel, and Hunwick teach the elements as described above with regards to claim 12.
Fang discloses a calcium-magnesium leaching solution of chemical ore dressing byproduct (pg. 8, paragraph 3).
Fang is silent to using sulfuric acid for acid leaching of the solids, and wherein a temperature of the acid leaching of the solids is between 75°C and 90°C.
Gu discloses acid leaching magnesium-containing ore using sulfuric acid (Abstract), wherein a temperature of the acid leaching of the ore is between 75°C and 80°C [0048].
Regarding the temperature of acid leaching in claim 13, between 75°C and 80°C taught by Gu meets the limitation of between 75°C and 90°C.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Gu wherein acid leaching of the solids uses sulfuric acid, and wherein a temperature of the acid leaching of the solids is between 75°C and 90°C, because using sulfuric acid and temperatures between 75°C and 90°C for acid leaching are process parameters well-known in the art of acid-leaching magnesium-containing ore, as taught by Gu.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860) and Gu (CN 101724748) and Thomson (US 2021/0317026).
Regarding Claim 14, Fang, Fan, Worsley, Nishikawa, Wrubel, Hunwick, and Gu teach the elements as described above with regards to claim 13.
Fang discloses carrying out a magnesium removing reaction to obtain magnesium hydroxide (a magnesium removing reaction to obtain magnesium hydroxide meets the limitation wherein the precipitated impurity is magnesium hydroxide; claim 1).
Fang is silent to precipitating magnesium hydroxide with a caustic material, wherein the caustic material is milk-of-lime.
Hunwick discloses milk of lime may be added to a blend of potassium, magnesium and lithium with chloride to precipitate the magnesium as insoluble magnesium hydroxide in order to remove magnesium, which can be a problem when present in high concentrations because both its sulphate and chloride are quite soluble in aqueous solutions [0109].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Hunwick wherein the caustic material is milk-of-lime, and wherein the precipitated impurity is magnesium hydroxide in order to remove magnesium, which can be a problem when present in high concentrations because both its sulphate and chloride are quite soluble in aqueous solutions, as recognized by Hunwick [0109].
Fang and Hunwick are silent to the addition of the caustic material adjusts the pH of the neutralized filtrate to approximately 11.
Hunwick, however, discloses milk of lime is added in appropriate quantities to precipitate the magnesium as insoluble magnesium hydroxide [0109].
Thomson discloses hydrated lime (aka Ca(OH)2, milk-of-lime) is added to raise the pH to 11 or greater which causes precipitation of magnesium hydroxide [0019].
Regarding the pH in claim 14, it appears that 11 or greater taught by Thomson overlaps the claimed range of approximately 11 such that the range taught by Thomson obviates the claimed range. See MPEP 2144.05 (I).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Hunwick and Thomson wherein the pH is adjusted to approximately 11 in order to precipitate the magnesium hydroxide, as recognized by Thomson [0019].
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860) and Gu (CN 101724748) and Thomson (US 2021/0317026) and Rastas (US 6,274,104).
Regarding Claim 15, Fang, Fan, Worsley, Nishikawa, Wrubel, Hunwick, Gu, and Thomson teach the elements as described above with regards to claim 14.
Fang discloses carrying out a magnesium removing reaction to obtain magnesium hydroxide (claim 1). Fang further discloses the pH value of the neutralized slurry is 6.0-7.5 (pg. 5, par. 12).
Regarding the pH in claim 15, it appears that 6.0-7.5 taught by Fang overlaps the claimed range of approximately 6.5 such that the range taught by Fang obviates the claimed range. See MPEP 2144.05 (I).
Fang is silent to recycling the magnesium hydroxide to neutralize the effluent slurry.
Rastas discloses precipitating magnesium hydroxide using calcium hydroxide (milk-of-lime is a calcium hydroxide solution and therefore precipitating magnesium hydroxide using calcium hydroxide meets the limitation of precipitating via the addition of milk-of-lime; Col. 8, lines 36-38), wherein the magnesium hydroxide can be reused as a neutralizing agent (Col. 1, line 67-Col. 2, line 1).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Rastas wherein the magnesium hydroxide is recycled to neutralize the effluent slurry to a pH of approximately 6.5 as magnesium hydroxide is a known neutralizing agent, as recognized by Rastas, and recycling is a well-known beneficial process which conserves resources.
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860) and Gu (CN 101724748) and Blei (US 2022/0356152).
Regarding Claim 17, Fang, Fan, Worsley, Nishikawa, Wrubel, and Hunwick teach the elements as described above with regards to claim 12.
Fang is silent to using Mechanical Vapor Recompression heated falling film evaporators to evaporate the neutralized filtrate at approximately 105°C.
Fang, however, discloses concentrating the neutralized liquid by evaporation at 100°C to 135°C (claim 6).
Regarding the evaporation temperature in claim 17, it appears that 100°C to 135°C taught by Fang overlaps the claimed value of 105°C such that the range taught by Fang obviates the claimed value. See MPEP 2144.05 (I).
Worsley discloses concentrating via evaporation (claim 1) by falling film MVR evaporators (falling film MVR evaporator meets the limitation of Mechanical Vapor Recompression heated falling film evaporator; claim 19, [0033]), which are evaporators known to have high rate of heat transfer and high energy efficiency (claim 19).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Worsley wherein the Mechanical Vapor Recompression heated falling film evaporators evaporate the neutralized filtrate at approximately 105°C in order to evaporate with a high rate of heat transfer and high energy efficiency, as recognized by Worsley (claim 19).
Fang is further silent to the first crystallization step occurring at approximately 65°C; the second crystallization step occurring at approximately 40°C; and the third crystallization step occurring at approximately 10°C.
Fang, however, teaches crystallizing potassium nitrate at room temperature (pg. 6, paragraph 9), which is between the claimed values of 40°C for the second crystallization step and 10°C for the third crystallization step.
Blei discloses crystallization in three steps with decreasing temperatures from step to step, with the first step occurring at 70°C to 110°C, the second step occurring at 20°C to 70°C, and the third step occurring at -10°C to 25°C [0048].
Regarding the first crystallization step temperature in claim 17, it appears that 70°C to 110°C taught by Blei is close to the claimed value of 65°C such that the range taught by Blei obviates the claimed range. See MPEP 2144.05 (I).
Regarding the second crystallization step temperature in claim 17, it appears that 20°C to 70°C taught by Blei overlaps the claimed value of 40°C such that the range taught by Blei obviates the claimed range. See MPEP 2144.05 (I).
Regarding the third crystallization step temperature in claim 17, it appears that -10°C to 25°C taught by Blei overlaps the claimed value of 10°C such that the range taught by Blei obviates the claimed range. See MPEP 2144.05 (I).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Blei wherein the first crystallization step occurs at approximately 65°C; the second crystallization step occurs at approximately 40°C; and the third crystallization step occurs at approximately 10°C, because decreasing temperatures from step to step when crystallizing in multiple steps is a process parameter well-known in the art of crystallization, as taught by Blei, in order to further improve the removal of impurities, absent a showing of unexpected results through routine experimentation (MPEP 2144.04 IV B).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860) and Gu (CN 101724748) and Blei (US 2022/0356152) and Phinney (US 2011/0123420).
Regarding Claim 18, Fang, Fan, Worsley, Nishikawa, Wrubel, Hunwick, Gu, and Blei teach the elements as described above with regards to claim 17.
Fang is silent to cooling by water from a cooling tower in the crystallization step.
Phinney discloses a crystallizer is cooled by water from a cooling tower [0049].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Phinney wherein the second crystallization step is cooled by water from a cooling tower, because using water for cooling in crystallization is a process parameter well-known in the art of crystallization, as taught by Phinney.
Claims 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860) and Gu (CN 101724748) and Blei (US 2022/0356152) and Phinney (US 2011/0123420) and Morrison (US 4,409,253).
Regarding Claim 19, Fang, Fan, Worsley, Nishikawa, Wrubel, Hunwick, Gu, Blei, and Phinney teach the elements as described above with regards to claim 18.
Fang is silent to cooling by a glycol-water mixture in the crystallization step.
Morrison discloses a crystallization step is cooled with an ethylene glycol-water mixture (Col. 11, lines 59-61).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Morrison wherein the third crystallization step is cooled with a glycol-water mixture, because using a glycol-water mixture for cooling in crystallization is a process parameter well-known in the art of crystallization, as taught by Morrison.
Regarding Claim 20, Fang is silent to cooling by a glycol-water mixture in the crystallization step, wherein the glycol mixture comprises ethylene glycol.
Morrison discloses a crystallization step is cooled with an ethylene glycol-water mixture (Col. 11, lines 59-61).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Morrison wherein the glycol-water mixture comprises ethylene glycol, because using an ethylene glycol-water mixture for cooling in crystallization is a process parameter well-known in the art of crystallization, as taught by Morrison.
Claim 25 is rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860) and Hook (US 2010/0193732).
Regarding Claim 25, Fang, Fan, Worsley, Nishikawa, Wrubel, and Hunwick teach the elements as described above with regards to claim 12.
Fang teaches crystallizing potassium nitrate from the neutralized liquid in a crystallization step (claim 1).
Fang is silent to the first crystallization step using a Mechanical Vapor Recompression heated forced circulation crystallizer under vacuum.
Wrubel discloses crystallizing potassium nitrate (the impurity crystallized in Fang) [0095], wherein the crystallizer is a forced circulation crystallizer, draft tube baffle crystallizer, or any combination thereof [0064].
Worsley discloses concentrating via evaporation (claim 1) by falling film MVR evaporators (claim 19, [0033]), which are evaporators known to have high rate of heat transfer and high energy efficiency (claim 19).
Hook discloses forced circulation evaporative crystallizer using mechanical vapor recompression to increase the temperature of the vapor stream and heat-exchanging the vapor stream with the crystallizer to provide heat to the crystallizer [0141].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Wrubel and Hook where the first crystallization step uses a mechanical vapor recompression heated forced circulation crystallizer, because utilizing mechanical vapor recompression with the heated forced circulation crystallizer provides heat to the crystallizer, as recognized by Hook [0141], which results in a high energy efficiency, as recognized by Worsley (claim 19).
Hunwick discloses a crystallizer based on the principle of mechanical vapour recompression, with evaporation occurring at sub-atmospheric pressure (sub-atmospheric pressure meets the limitation of under vacuum; [0196].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Hunwick wherein the first crystallization step using a Mechanical Vapor Recompression crystallizer under vacuum, because operating a crystallizer based on mechanical vapor recompression under vacuum is a process parameter well known in the art of mechanical vapor recompression crystallizers, as recognized by Hunwick [0196].
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860) and Ore (US 4,260,584).
Regarding Claim 27, Fang, Fan, Worsley, Nishikawa, Wrubel, and Hunwick teach the elements as described above with regards to claim 12.
Fang is silent to one or more of the second crystallization step or the third crystallization step comprises removing water vapor and non-condensable gases by ejector or barometric condenser trains cooled by water from a cooling tower.
Ore discloses vapor (vapor meets the limitation of water vapor and non-condensable gases) is withdrawn from a crystallizer and passes to a barometric condenser (barometric condenser meets the limitation of barometric condenser trains) into which cooling water (cooling water meets the limitation of water from a cooling tower) is sprayed to cool the vapors (Col. 28, lines 40-44).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Ore one or more of the second crystallization step or the third crystallization step comprises removing water vapor and non-condensable gases by ejector or barometric condenser trains cooled by water from a cooling tower as this is a process parameter well-known in the art of treating vapors from crystallizers, as recognized by Ore.
Claim 28 is rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860) and Gu (CN 101724748) and Blei (US 2022/0356152) and Phinney (US 2011/0123420) and Morrison (US 4,409,253) and Moyers (US 5,675,022).
Regarding Claim 28, Fang, Fan, Worsley, Nishikawa, Wrubel, Hunwick, Gu, Blei, Phinney, and Morrison teach the elements as described above with regards to claim 19.
Fang is silent to cooling by a glycol-water mixture in the crystallization step.
Moyers discloses a crystallizer is cooled by a propylene glycol/water coolant (Col. 7, lines 8-11).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Moyers wherein the third crystallization step is cooled with a propylene glycol water mixture, because using a propylene glycol-water mixture for cooling in crystallization is a process parameter well-known in the art of crystallization, as taught by Moyers.
Claim 29 is rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860) and Maccagni (US 2021/0025026).
Regarding Claim 29, Fang, Fan, Worsley, Nishikawa, Wrubel, and Hunwick teach the elements as described above with regards to claim 12.
Fang discloses a decalcification reaction to obtain calcium sulphate (claim 1).
Fang is silent to precipitating calcium sulphate as the precipitated impurity.
Maccagni discloses a precipitating agent is added to a leachate, wherein the precipitating agent may be Ca(OH)2 (Ca(OH)2 meets the limitation of a caustic material) to form calcium sulfate [0049].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Maccagni wherein the precipitated impurity comprises calcium sulfate, because adding a caustic material a leachate forms calcium sulfate, as recognized by Maccagni, and selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results (MPEP 2144.04 IV C).
Claim 31 is rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860) and Johnson (US 10,894,997).
Regarding Claim 31, Fang, Fan, Worsley, Nishikawa, Wrubel, and Hunwick teach the elements as described above with regards to claim 12.
Fang is silent to neutralizing the effluent slurry by combining the effluent slurry with slurry of ground limestone to increase a pH of the effluent slurry to a target pH of less than or equal to 4.
Johnson discloses a process for the recovery of lithium from minerals rich in lithium and phosphate (Abstract). Johnson further discloses precipitating impurities in a pregnant leach solution (PLS) after leaching (PLS is formed by acid-leaching and therefore meets the limitation of an effluent slurry; Col. 3, lines 16-20) by the addition of limestone ( at a pH of between 2 to 3 (Col. 7, lines 11-20). Johnson further teaches the limestone may be in the form of a slurry (Col. 7, lines 26-29).
Regarding the pH in claim 31, it appears that 2 to 3 taught by Johnson overlaps the claimed range of less than or equal to 4 such that the range taught by Johnson obviates the claimed range. See MPEP 2144.05 (I).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Johnson to neutralize the effluent slurry by combining the effluent slurry with slurry of ground limestone to increase a pH of the effluent slurry to a target pH of less than or equal to 4 in order to precipitate impurities, as recognized by Johnson (Col. 7, lines 11-20).
Claim 32 is rejected under 35 U.S.C. 103 as being unpatentable over Fang (CN 112758971) in view of Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860) and Lee (US 2021/0130926).
Regarding Claim 32, Fang, Fan, Worsley, Nishikawa, Wrubel, and Hunwick teach the elements as described above with regards to claim 12.
Fang is silent to neutralizing the effluent slurry by adding a stream of limestone to a magnesium hydroxide stream to form a neutralizing stream.
Lee discloses acid-leaching followed by neutralization [0081] of an ore [0021], wherein the neutralizing agent comprises limestone and Mg(OH)2 [0089].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Fang to incorporate the teachings of Lee to neutralize the effluent slurry by adding a stream of limestone to a magnesium hydroxide stream to form a neutralizing stream, because using limestone and magnesium hydroxide as neutralizing agents of an ore following acid-leaching is a process parameter well-known in the art of treating ores, as recognized by Lee.
Response to Arguments
Applicant’s arguments, see "Remarks", pg. 6, par. 2-3, filed 15 April 2026, with respect to the rejection(s) of claim(s) 12-15 and 17-20 under 35 U.S.C. 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Fang (CN 112758971) and Fan (WO 2019015013) and Worsley (US 2015/0086452) and Nishikawa (JP 2022164547) and Wrubel (US 2015/0321924) and Hunwick (US 2021/0387860).
Applicant's arguments filed 15 April 2026 have been fully considered but they are not persuasive.
Applicant argues Nishikawa does not disclose generally preventing the crystallization of lithium, and Nishikawa discloses preventing crystallization of lithium carbonate, not a lithium-potassium double salt (“Remarks”, pg. 7, par. 2-3).
However, Campbell (“THE SYSTEMS Li2SO4-K2SO4-H2O AND Li2SO4-Na2SO4-H2O AT 25°C”) teaches precipitating a lithium-potassium double salt at 11.0 wt% Li2SO4 and the lithium-potassium double salt was not precipitated at 10.6 wt% Li2SO4 at 25°C (pg. 172, Table II). 10.6 wt% Li2SO4 is approximately 13,400 mg/L lithium, which is greater than the maximum lithium concentration of 4,000 mg/L taught by Nishikawa, such that crystallization of lithium is generally prevented, and crystallization of a lithium-potassium salt is prevented at a concentration of lithium below 4,000 mg/L as taught by Nishikawa.
In response to applicant's argument that the examiner has combined an excessive number of references, reliance on a large number of references in a rejection does not, without more, weigh against the obviousness of the claimed invention. See In re Gorman, 933 F.2d 982, 18 USPQ2d 1885 (Fed. Cir. 1991).
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
Applicant argues parameters involving crystallization of 4,4’-dichlorodiphenyl sulfone would not lead to the skilled artisan to the temperatures ranges recited in claim 17 for lithium-containing solids (“Remarks”, pg. 8, par. 6).
However, Fang teaches crystallizing at room temperature, which is within the claimed temperature range for the crystallization steps, and Fang in view of Wrubel teaches crystallizing in multiple steps (see rejection of claim 1). Blei is relied upon to teach decreasing temperatures from step to step when crystallizing in multiple steps at temperatures overlapping room temperature. It would have been necessary and obvious for a person having ordinary skill in the art to look to the prior art for exemplary temperatures used when crystallizing in multiple steps around room temperature, despite the difference in materials being crystallized. When applying multiple crystallization steps around room temperature, the crystallization of the impurities is a variable that can be modified by adjusting the crystallization temperature, and the precise temperature would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, discovery of optimum ranges of a result effective variable in a known process is ordinarily within the skill of art and selection of the optimum ranges within the general condition is obvious (MPEP 2144.05 (II)).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SLONE ELZABETH SIMKINS whose telephone number is (571)272-3214. The examiner can normally be reached Monday - Friday 8:30AM-4:30PM.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, KEITH WALKER can be reached at (571)272-3458. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/S.E.S./Examiner, Art Unit 1735
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735
Prosecution Insights