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 .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 16 February 2026 has been entered.
Information Disclosure Statements
The Information Disclosure Statements filed on 7 November 2025 and 16 February 2026 have been received and considered by the Examiner.
Claim Amendments
Applicant’s amendment to claim 3 and new claim 23, filed 16 February 2026, have been entered and considered for this action, though it is noted that the status indicator for claim 3 should read “Currently amended”.
Claim Interpretation
Amended claim 3 presently recites “wherein the biological leaching reagent comprises a glycolipid biosurfactant and at least one of a fermentation broth containing microbes, other growth byproducts.” This is interpreted as requiring a glycolipid biosurfactant, and additionally requiring at least one of (i) a fermentation broth containing microbes and (ii) other growth byproducts. The glycolipid biosurfactant may be present in the fermentation broth containing microbes, or may be provided separately.
This is notably distinct from the unamended version of the claim that recited as one composition (i) a fermentation broth containing microbes, a biosurfactant, and other growth byproducts.
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 3-6 and 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over Benredjem et al. (Sep. Sci. Tech. 2016, 51(4), 718-726) in view of Singh et al. (Environ Sci Pollut Res 2013, 20, 7367–7376), Rangarajan et al. (Colloids and Surfaces B: Biointerfaces 2013, 104, 99– 106), and Ye et al. (Ecotox. Environ. Safety 2016, 124, 344–350).
Regarding claim 3, Benredjem teaches a method for extracting an impurity from phosphate ore (removing cadmium from phosphate ore, title) comprising (i) obtaining the phosphate ore, said ore comprising phosphate and an impurity (phosphate ore sample was collected; p. 719, column 1, sampling and characterization phosphate ore; impurities shown in Table 1); (ii) contacting a composition comprising an acid (acetic acid solution, p. 719, column 1, paragraph 6) and a pH adjuster (adjustment of the pH [of the] solution was carried out with NaOH; p. 719, column 1, Reagents) with the ore for a period of time to yield a mixture comprising a treated phosphate ore and an impurity that has reacted with the composition (leaching experiment consists of contacting a phosphate ore mass with 50 mL acetic acid solution…the mixture was stirred; p. 719, column 1, Batch leaching with extracting agent); and (iii) separating the reacted impurity and composition from the mixture to obtain a reduced-impurity phosphate-containing material (the mixture was centrifuged and filtered…recovered solid phase was washed with deionized water and then was dried; p. 719, column 1, Batch leaching with extracting agent). Figures 4-6 show that at least some cadmium was removed from the phosphate ore by reacting them with the composition (dissolving in the leaching solution; p. 718, column 2, paragraph 4).
Benredjem also teaches the addition of different organic extracting agents to the mixtures (p. 720, column 2) to aid in the extraction efficiency of cadmium from the phosphate ore. Benredjem does not teach the composition comprising a biological leaching reagent where the biological leaching reagent comprises a glycolipid biosurfactant and at least one of a fermentation broth containing microbes, other growth byproducts.
However, Singh teaches that lipopeptide biosurfactants can be used to remove heavy metal contaminants, including cadmium, from contaminated soils (washing with mixture of lipopeptide biosurfactants … can be an efficient and environment friendly approach for removing pollutants (petroleum hydrocarbon and heavy metals) from contaminated soil; abstract). Singh further teaches that their method could be applied to ores (The application of anionic biosurfactant in extraction of metal from ores can be greener and environment friendly approach; Conclusion, ¶ 2), suggesting that techniques applicable to soil are analogous to those applicable to ores.
Singh does not teach using a biological leaching reagent comprising fermentation broth containing microbes or the biological leaching reagent comprising a glycolipid biosurfactant.
However, Rangarajan teaches that a biological reagent comprising a fermentation broth containing microbes, biosurfactants and other growth byproducts (biosurfactant broth with cells (BBWC); section 2.2.3) can be used to remove divalent metal ions (almost complete removal of the metal from the solution; p. 104, col. 2, ¶ 4), and that heavier metal ions show a greater affinity toward lipopeptide biosurfactant (Ca2+ ions being heavier than Mg2+ ions might have showed greater affinity toward lipopeptide and thereby resulted in more amount of Ca2+ in the foamate; p. 104, col.2, ¶ 3). Rangarajan further teaches that their method provides an inexpensive strategy for recovery of metals from ores (title and abstract).
Furthermore, Ye teaches that a glycolipid biosurfactant (sophorolipid) is effective in extracting cadmium from contaminated soils (washings with …the sophorolipid …were effective in removing Cd; p. 349, Section 4).
It is noted that the courts have held that "It is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose.... [T]he idea of combining them flows logically from their having been individually taught in the prior art." In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980). MPEP 2144.06(I).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention to replace the electrodialysis in the method of Benredjem with the use the biological reagent comprising a lipopeptide biosurfactant in the fermentation broth taught by Rangarajan as an alternative method to remove cadmium ions from solution. One of ordinary skill in the art would have been motivated to do so because Benredjem is trying to remove cadmium and Singh teaches that lipopeptide biosurfactants are effective at removing cadmium impurities, while Rangarajan teaches that their fermentation broth is a cost-effective way to utilize biosurfactants for removal of metal ions from ores. One would have been further motivated to include sophorolipids, a type of glycolipid, in the mix because Ye teaches that they too are effective at removing cadmium from contaminated materials and it is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose.
Alternatively, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to replace the electrodialysis in the method of Benredjem with the use of a biological reagent comprising sophorolipid biosurfactant in a fermentation broth. One of ordinary skill in the art would have been motivated to do so because Ye teaches that sophorolipids, like the lipopeptides of Singh, are effective at removing cadmium from contaminated materials while Rangarajan teaches that using entire fermentation broths containing metal-binding biosurfactants provides an inexpensive route to removing metals from ores.
Regarding claim 4, modified Benredjem teaches the method of claim 3, where Benredjem also teaches the acid is acetic acid (p. 719, column 1, paragraph 6), thereby meeting the limitations of claim 4.
Regarding claim 5, modified Benredjem teaches the method of claim 3, wherein the pH adjuster is present in the composition at a concentration that stabilizes the pH of the composition at pH 4 (Fig. 9 and p. 723, column 2, paragraph 1), meeting the limitations of claim 5 which require the pH of the composition being between 2 and 5.
Regarding claim 6, modified Benredjem teaches the pH adjuster being sodium hydroxide (p. 719, column 1, Reagents).
Regarding claims 11 and 12, modified Benredjem teaches the method of claim 3, as analyzed above, where the impurity is cadmium, thereby meeting the limitations of claims 11 and 12.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Benredjem et al. (Sep. Sci. Tech. 2016, 51(4), 718-726) in view of Singh et al. (Environ Sci Pollut Res 2013, 20, 7367–7376), Rangarajan et al. (Colloids and Surfaces B: Biointerfaces 2013, 104, 99– 106), and Ye et al. (Ecotox. Environ. Safety 2016, 124, 344–350), as applied to claim 3, and further in view of Gharabaghi et al. (Hydrometallurgy, 2010, 103, 96-107) as evidenced by Mezghache et al. (Phosphorus Research Bulletin, 2004, 15, 5-20).
Regarding claim 7, modified Benredjem teaches the method of claim 3, as analyzed above, but does not explicitly teach crushing, grinding, or pulverizing the phosphate ore into particles less than 500 nm in size prior to step (ii).
However, Gharabaghi teaches that the efficiency of the leaching process can be increased by fine grinding of the phosphate feed (p. 102, column 1, paragraph 2).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention to grind the phosphate ore into fine particles prior to leaching (step (ii)) as taught by Gharabaghi in the method described by modified Benredjem. One of ordinary skill would have been motivated to do so in order to increase the efficiency of leaching, as taught by Gharabaghi.
Regarding the particle size being less than 500 nm, Gharabaghi also teaches that particle size is a variable that affects leaching rate and efficiency (leaching rate of carbonate minerals and its efficiency increased with a decrease in particle size and associated increase in surface area; p. 101, column 2, paragraph 2, Section 4.4). Mezghache provides evidence that phosphate ores of the Djebel Onk deposit used by Benredjem (p. 719, paragraph 5) are types of carbonate minerals (phosphatic matter is formed by … the association of a carbonated fluorapatite … and a sulfo-carbonate; p. 7, Mineralogy and Petrography).
As the leaching rate and efficiency are variables that can be modified, among others, by adjusting the particle size with rate and efficiency both increasing as particle size is decreased, the precise particle size 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 particle size 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 particle size in the method of modified Benredjem to obtain the desired balance between the rate and efficiency and grinding cost, as taught by Gharabaghi (Section 4.4) 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).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Benredjem et al. (Sep. Sci. Tech. 2016, 51(4), 718-726) in view of Singh et al. (Environ Sci Pollut Res 2013, 20, 7367–7376), Rangarajan et al. (Colloids and Surfaces B: Biointerfaces 2013, 104, 99– 106), and Ye et al. (Ecotox. Environ. Safety 2016, 124, 344–350), as applied to claim 3, and further in view of Armarego et al. (Purification of Laboratory Chemicals, 6e, 2009, Elsevier, p. 15).
Regarding claim 8, modified Benredjem teaches the method of claim 3, as analyzed above, where the composition is in liquid form (acetic acid solution is a liquid; p. 719, column 1) and wherein step (ii) comprises stirring the mixture for a various time periods, including 1 hour, 2 hours and 10 hours (Figure 6), which meet the claim limitation of 10 min to 48 hours, and wherein the reacted impurity and composition of step (iii) is present in the liquid phase and the phosphate ore remains a solid that is filtered out of the liquid (the mixture was centrifuged and filtered, the recovered solid phase was washed; p. 719, column 1). Benredjem teaches that the solid is centrifuged and filtered, but not explicitly that it is decanted.
However, Armarego teaches that the technique of centrifugation to isolate fine solids often involves a decanting step to remove the supernatant from the centrifuge tube (after decanting the supernatant; p. 15, paragraph 4).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to apply a decanting step as taught by Armarego in the centrifuging and filtering method of modified Benredjem. One of ordinary skill in the art would have been motivated to do so because Armarego teaches this as effective method to remove supernatants when centrifuging fine solids.
Claims 9 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Benredjem et al. (Sep. Sci. Tech. 2016, 51(4), 718-726) in view of Singh et al. (Environ Sci Pollut Res 2013, 20, 7367–7376), Rangarajan et al. (Colloids and Surfaces B: Biointerfaces 2013, 104, 99– 106), and Ye et al. (Ecotox. Environ. Safety 2016, 124, 344–350), as applied to claim 3, and further in view of Goyne et al. (Chemical Geology, 2010, 278, 1–14), Gharabaghi et al. (Hydrometallurgy, 2010, 103, 96-107), and Armarego et al. (Purification of Laboratory Chemicals, 6e, 2009, Elsevier, p. 15).
Regarding claims 9 and 10, modified Benredjem teaches the method of claim 3, where step (iii) comprises applying a washing fluid comprising water wherein the washing fluid will comprise the reacted impurity and composition and the phosphate ore remains a solid that is isolated from the fluid (the recovered solid phase was washed with deionized water, p. 719, column 1, paragraph 6). This washing will further remove the reacted impurity and composition left among the insoluble solids.
Benredjem does not teach the washing fluid comprising an organic solvent, agitating for a period of time, or explicitly mention decanting and filtering out of the fluid in the washing step.
However, washing steps that comprise an organic solvent, agitating for a period of time and isolating solids by decanting and filtering are well known in the art.
In particular, Goyne teaches the washing of a mineral pellet with ethanol following extraction of rare earth elements from a phosphate mineral ore (p. 3, column 2, paragraph 1).
Therefore, it would have been obvious to one of ordinary skill in the art to further modify the method of Benredjem to add ethanol, an organic solvent that is an alcohol (meeting claims 9 and 10), in the washing fluid, as taught by Goyne. One of ordinary skill would have found this modification obvious because it is the combination of two known washing techniques for phosphate minerals with predictable result of purifying the product.
Regarding agitating for a period of time of about 10 minutes to 60 minutes, the purpose of a wash is to remove impurities (and increase the purity of the solids) much like that of step (ii), the leaching step. Gharabaghi teaches that stirring speed and time are both result effective variables for increasing phosphate content (and decreasing impurities) of the remaining solid ore in a leaching process (P2O5 content of the remaining solids increased with an increase in the stirring speed to 200-350 rpm, Section 4.5). Stirring will necessarily happen over a period of time.
Therefore, it would have been obvious to one of ordinary skill in the art to further modify the method of Benredjem to apply the washing fluid to the mixture under stirring (a form of agitation) for a period of time (because stirring will necessarily occur over some period of time), as taught by Gharabaghi. One of ordinary skill would have been motivated to do so because Gharabaghi teaches that stirring increases the purity of the product being washed.
Furthermore, one of ordinary skill in the art would have found it obvious to optimize the time of the stirring by routine experimentation because Gharabaghi teaches that reaction time is a result-effective variable for increasing the purity of the product (increasing reaction times up to the optimum value, the P2O5 percentage increases along with the corresponding reduction [in impurities]; Section 4.3).
It is again noted that the courts have held that where 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).
Lastly, Benredjem teaches that the purified phosphate ore is isolated by centrifuging and filtering the washed solid (the mixture was centrifuged and filtered, the recovered solid phase; p. 719, column 1, paragraph 6) but does not explicitly mention decanting. However, Armarego teaches that the technique of centrifugation to isolate fine solids often involves a decanting step to remove the supernatant from the centrifuge tube (after decanting the supernatant; p. 15, paragraph 4).
Therefore, one of ordinary skill in the art would have found it obvious to further modify the method of modified Benredjem to include a step wherein the phosphate ore solid is isolated following washing by decanting and filtering out of the liquid because Armarego teaches that decanting can be used to effectively isolate solids from a solid-liquid mixture as an additional part of a method that involves centrifuging, as taught by modified Benredjem. In conclusion, all the method steps and limitations of claims 9 and 10 are therefore taught by the combination of Benredjem, Goyne, Gharabaghi and Armarego.
Claim 23 is rejected under 35 U.S.C. 103 as being unpatentable over Benredjem et al. (Sep. Sci. Tech. 2016, 51(4), 718-726) in view of Singh et al. (Environ Sci Pollut Res 2013, 20, 7367–7376), Rangarajan et al. (Colloids and Surfaces B: Biointerfaces 2013, 104, 99– 106), and Ye et al. (Ecotox. Environ. Safety 2016, 124, 344–350), as applied to claim 3, and further in view of Mulligan et al. (Environ. Progress 1999, 18(1), 50-54).
Regarding claim 23, modified Benredjem teaches the method of claim 3, where Ye teaches the glycolipid biosurfactant is a sophorolipid, but neither Benredjem nor Ye specifically teach the sophorolipid being harvested from yeast cell biomass.
However, Mulligan teaches that sophorolipid biosurfactants to be used for heavy metal removal (title) can be harvested from yeast cell biomass (Several experiments have been performed using the sophorolipid produced by the yeast Tomlopsis bombicola. It is isolated from the fermentation medium by solvent extraction with ethyl acetate; p. 51, col. 2, Sophorolipid).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to obtain the sophorolipid used in the method of modified Benredjem from yeast cell biomass, as taught by Mulligan. One of ordinary skill in the art would have been motivated to do so because while Ye teaches the use of sophorolipids, they do not teach the source of them, while Mulligan teaches how to obtain them.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 3-6, 11-12 and 23 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-8 of U.S. Patent No. 12,000,016 B2 in view of Benredjem et al. (Sep. Sci. Tech. 2016, 51(4), 718-726).
Regarding instant claim 3, claim 1 of the ‘016 patent discloses a method of extracting an impurity (metals) from ore, the method comprising: (i) obtaining the ore; (ii) contacting a composition comprising a biological leaching reagent (applying a biological leaching agent comprising a biosurfactant) with the ore for a period of time to yield a mixture comprising a treated ore and an impurity that has reacted with the composition (allowing the metals to separate from the ore); and (iii) separating the reacted impurity and composition from the mixture to obtain a reduced-impurity containing material (collecting the minerals and/or metals from the slurry), wherein the biological leaching reagent comprises fermentation broth containing microbes, biosurfactants and other growth byproducts (Starmarella bombicola yeast and/or a growth product thereof, wherein the growth product is a biosurfactant; other growth products will also be present with the yeast cells).
The claims of the ‘016 patent do not teach the ore being phosphate ore, or the composition comprising an acid or pH adjuster.
However, Benredjem teaches that phosphate ores can be subjected to extraction methods, and that such methods additionally comprise a composition containing an acid (p. 719, column 1, Batch leaching with extracting agent ) and a pH adjuster (p. 719, column 1, Reagents; meeting claim 6).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to apply to methods of claim 1 of the ‘016 patent to phosphate ores, and to additionally include an acid and pH adjuster in the leaching composition. One of ordinary skill in the art would have been motivated to do so because there is a recognized desire to remove metals from phosphate ores, as taught by Benredjem.
Regarding instant claims 4-6, Benredjem teaches the additional limitations of these claims teaches where the acid is acetic acid (p. 719, column 1, Batch leaching with extracting agent, meeting claim 4), the pH adjuster is present in the composition at a concentration that stabilizes the pH of the composition at pH 4 (Fig. 9 and p. 723, column2, paragraph 1; meeting claim 5), and the pH adjuster is sodium hydroxide (p. 719, column 1, Reagents; meeting claim 6).
Regarding instant claim 11-12, Benredjem teaches the impurity being cadmium, meeting the limitations of the instant claims.
Claim 7 is rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-8 of U.S. Patent No. 12,000,016 B2 in view of Benredjem et al. (Sep. Sci. Tech. 2016, 51(4), 718-726), as applied to claim 3, and further in view of Gharabaghi et al. (Hydrometallurgy, 2010, 103, 96-107) as evidenced by Mezghache et al. (Phosphorus Research Bulletin, 2004, 15, 5-20).
Regarding instant claim 7, modified claim 1 of the ‘016 patent teaches the method of claim 3, as analyzed above, but does not explicitly teach crushing, grinding, or pulverizing the phosphate ore into particles less than 500 nm in size prior to step (ii).
However, Gharabaghi teaches that the efficiency of the leaching process can be increased by fine grinding of the phosphate feed (p. 102, column 1, paragraph 2).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention to grind the phosphate ore into fine particles prior to leaching (step (ii)) as taught by Gharabaghi in the method described by modified claim 1. One of ordinary skill would have been motivated to do so in order to increase the efficiency of leaching, as taught by Gharabaghi.
Regarding the particle size being less than 500 nm, Gharabaghi also teaches that particle size is a variable that affects leaching rate and efficiency (leaching rate of carbonate minerals and its efficiency increased with a decrease in particle size and associated increase in surface area; p. 101, column 2, paragraph 2, Section 4.4). Mezghache provides evidence that phosphate ores of the Djebel Onk deposit used by Benredjem (p. 719, paragraph 5) are types of carbonate minerals (phosphatic matter is formed by … the association of a carbonated fluorapatite … and a sulfo-carbonate; p. 7, Mineralogy and Petrography).
As the leaching rate and efficiency are variables that can be modified, among others, by adjusting the particle size with rate and efficiency both increasing as particle size is decreased, the precise particle size 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 particle size 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 particle size in the method of modified ‘016 patent to obtain the desired balance between the rate and efficiency and grinding cost, as taught by Gharabaghi (Section 4.4) 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).
Claim 8 is rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-8 of U.S. Patent No. 12,000,016 B2 in view of Benredjem et al. (Sep. Sci. Tech. 2016, 51(4), 718-726), as evidenced by Kurtzman et al. (FEMS Microbiol. Lett. 2010, 311(2), 140-146), as applied to claim 3, and further in view of Armarego et al. (Purification of Laboratory Chemicals, 6e, 2009, Elsevier, p. 15).
Modified claim 1 of the ‘016 patent teaches the method of instant claim 3, as analyzed above, and Benredjem further teaches the composition being in liquid form (acetic acid solution is a liquid; p. 719, column 1) and wherein step (ii) comprises stirring the mixture for a time period of 2 hours (Figure 6, inset) and wherein the reacted impurity and composition of step (iii) is present in the liquid phase and the phosphate ore remains a solid that is separated and filtered out of the liquid (the mixture was centrifuged and filtered, the recovered solid phase was washed; p. 719, column 1; centrifugation involves the collection of material at the bottom of a centrifuge tube, from which the liquid is decanted). Armarego teaches that a decanting step can be included in the centrifugation as a method to remove a supernatant, which contains the soluble fraction (p. 15, paragraph 4).
Therefore, it would have been obvious to one of ordinary skill in the art to include these steps in the method of modified claim 1. One of ordinary skill in the art would have been motivated to do so because Benredjem teaches that they are effective at removing cadmium from the phosphate ore, and Armarego teaches that the centrifugation and decanting are effective at washing fine solids (p. 15, paragraph 4).
Claims 9 and 10 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-8 of U.S. Patent No. 12,000,016 B2 in view of Benredjem et al. (Sep. Sci. Tech. 2016, 51(4), 718-726), as applied to claim 3, and further in view further in view of Goyne et al. (Chemical Geology, 2010, 278, 1–14), Gharabaghi et al. (Hydrometallurgy, 2010, 103, 96-107), and Armarego et al. (Purification of Laboratory Chemicals, 6e, 2009, Elsevier, p. 15).
The claims of the ‘016 patent, as modified by Benredjem, teach the method of claim 3, where Benredjem teaches step (iii) comprising applying a washing fluid comprising water wherein the washing fluid will comprise the reacted impurity and composition and the phosphate ore remains a solid that is isolated from the fluid (the recovered solid phase was washed with deionized water, p. 719, column 1, paragraph 6). This washing will further remove the reacted impurity and composition left among the insoluble solids.
The ‘016 patent nor Benredjem teach the washing fluid comprising an organic solvent, agitating for a period of time, or explicitly mention decanting and filtering out of the fluid in the washing step.
However, washing steps that comprise an organic solvent, agitating for a period of time and isolating solids by decanting and filtering are well known in the art.
In particular, Goyne teaches the washing of a mineral pellet with ethanol following extraction of rare earth elements from a phosphate mineral ore (p. 3, column 2, paragraph 1).
Therefore, it would have been obvious to one of ordinary skill in the art to further modify the method of the ‘016 patent to add ethanol, an organic solvent that is an alcohol (meeting claims 9 and 10), in the washing fluid, as taught by Goyne. One of ordinary skill would have found this modification obvious because it is the combination of two known washing techniques for phosphate minerals with predictable result of purifying the product.
Regarding agitating for a period of time of about 10 minutes to 60 minutes, the purpose of a wash is to remove impurities (and increase the purity of the solids) much like that of step (ii), the leaching step. Gharabaghi teaches that stirring speed and time are both result effective variables for increasing phosphate content (and decreasing impurities) of the remaining solid ore in a leaching process (P2O5 content of the remaining solids increased with an increase in the stirring speed to 200-350 rpm, Section 4.5). Stirring will necessarily happen over a period of time.
Therefore, it would have been obvious to one of ordinary skill in the art to further modify the method of the ‘016 patent to apply the washing fluid to the mixture under stirring (a form of agitation) for a period of time (because stirring will necessarily occur over some period of time), as taught by Gharabaghi. One of ordinary skill would have been motivated to do so because Gharabaghi teaches that stirring increases the purity of the product being washed.
Furthermore, one of ordinary skill in the art would have found it obvious to optimize the time of the stirring by routine experimentation because Gharabaghi teaches that reaction time is a result-effective variable for increasing the purity of the product (increasing reaction times up to the optimum value, the P2O5 percentage increases along with the corresponding reduction [in impurities]; Section 4.3).
It is again noted that the courts have held that where 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).
Lastly, Benredjem teaches that the purified phosphate ore is isolated by centrifuging and filtering the washed solid (the mixture was centrifuged and filtered, the recovered solid phase; p. 719, column 1, paragraph 6) but does not explicitly mention decanting. However, Armarego teaches that the technique of centrifugation to isolate fine solids often involves a decanting step to remove the supernatant from the centrifuge tube (after decanting the supernatant; p. 15, paragraph 4).
Therefore, one of ordinary skill in the art would have found it obvious to further modify the method of the ‘016 patent to include a step wherein the phosphate ore solid is isolated following washing by decanting and filtering out of the liquid because Armarego teaches that decanting can be used to effectively isolate solids from a solid-liquid mixture as an additional part of a method that involves centrifuging, as taught by modified Benredjem. In conclusion, all the method steps and limitations of claims 9 and 10 are therefore obvious over the claims of the ‘016 patent in combination with Benredjem, Goyne, Gharabaghi and Armarego.
Claims 3-7 and 11-12 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 6-13 of copending Application No. 18/297,604 in view of Rangarajan et al. (Colloids and Surfaces B: Biointerfaces 2013, 104, 99– 106).
Regarding instant claim 3, claim 6 of the ‘604 application teaches a method for extracting an impurity from an ore, the method comprising:(i) obtaining the ore, said ore comprising a desirable component and an impurity; (ii) contacting a composition comprising a biosurfactant, an acid, and, optionally, a pH adjuster, with the ore and (iii) separating the impurity from the other components. Claim 6 does not teach a phosphate ore or a biological leaching reagent comprising s glycolipid and at least one of a fermentation broth containing microbes and other growth byproducts.
However, claim 7 teaches use of the method on phosphate ores and claim 10 teaches the use of a glycolipid biosurfactant (sophorolipid). Furthermore, Rangarajan teaches a biological reagent that is a fermentation broth containing microbes, biosurfactants and other growth byproducts (biosurfactant broth with cells (BBWC); section 2.2.3). Rangarajan further teaches that the broth can be used to remove divalent metal ions (almost complete removal of the metal from the solution; p. 104, col. 2, ¶ 4), and that heavier metal ions show a greater affinity toward lipopeptide biosurfactant (Ca2+ ions being heavier than Mg2+ ions might have showed greater affinity toward lipopeptide and thereby resulted in more amount of Ca2+ in the foamate; p. 104, col.2, ¶ 3). Rangarajan also teaches that their method provides an inexpensive strategy for recovery of metals from ores (title and abstract).
Therefore, it would have been obvious to one of ordinary skill in the art to apply the method of claims 6 and 8-13 using phosphate ores, as taught by claim 7, using glycolipid biosurfactants, as taught by claim 10, and additionally with the biosurfactant-containing biological leaching agent of Rangarajan. One of ordinary skill would have been motivated to do so because the claim 7 of the ‘604 application teaches that phosphate ores are an appropriate ore and Rangarajan teaches that use of the whole fermentation broth is an inexpensive strategy to remove (recover) metals from ores.
It is noted that the courts have held that "It is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose.... [T]he idea of combining them flows logically from their having been individually taught in the prior art." In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980). MPEP 2144.06(I).
The remaining limitations of instant claims 4-7, 11, and 12 are also taught by claims 8-13 of the ‘604 application, and it would have been obvious to one of ordinary skill in the art to add them to the method of modified claim 6. One of ordinary skill would have been motivated to do so because the claims teach these possibilities individually for combination with claim 6, and it would have therefore been obvious to combine them together with the modifications of Rangarajan and claim 7 with predictable results and a reasonable expectation of success. MPEP 2143(I)(A).
This is a provisional nonstatutory double patenting rejection.
Claim 23 is provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 6-13 of copending Application No. 18/297,604 in view of Rangarajan et al. (Colloids and Surfaces B: Biointerfaces 2013, 104, 99– 106), as applied to claim 3 above, and further in view of Mulligan et al. (Environ. Progress 1999, 18(1), 50-54).
Regarding claim 23, modified claim 6 of the ‘604 application teaches the method of claim 3, where claim 10 recites using a glycolipid biosurfactant that is a sophorolipid, but the ‘604 application does not specifically recite that the sophorolipid be harvested from yeast cell biomass.
However, Mulligan teaches that sophorolipid biosurfactants to be used for heavy metal removal (title) can be harvested from yeast cell biomass (Several experiments have been performed using the sophorolipid produced by the yeast Tomlopsis bombicola. It is isolated from the fermentation medium by solvent extraction with ethyl acetate; p. 51, col. 2, Sophorolipid).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to obtain the sophorolipid used in the method of the ‘604 application from yeast cell biomass, as taught by Mulligan. One of ordinary skill in the art would have been motivated to do so because while the ‘604 application teaches recites using sophorolipids, they do not teach the source of them, while Mulligan teaches how to obtain them.
This is a provisional nonstatutory double patenting rejection.
Response to Arguments
Applicant’s arguments, see pages 7-8 of the reply filed 16 February 2026, with respect to the rejection of claim(s) 3 under 35 USC § 103 have been fully considered and are persuasive. Therefore, the prior rejection has been withdrawn. However, upon further consideration, a new ground of rejection is made in view of the additional teaching provided by Ye, as analyzed above.
In particular, Applicant is correct that neither Benredjem or Rangarajan teach the use of a glycolipid biosurfactant. While Singh does teach that soil washing by rhamnolipids, a glycolipid biosurfactant, was also found to remove metals (p. 7374, ¶ 2), the rejection above relies upon Ye to teach that sophorolipids are effective at removing chromium.
Applicant previously argued, page 7 of the reply filed 19 September 2025, that the teachings of Ye were not equivalent to using the complex biological leaching reagent of claim 1, and that removing Cd from soil was not functionally equivalent to removing Cd with electrodialysis from ore. However, the rejections presented above now only use Ye to teach inclusion of sophorolipids as part of the leaching composition to arrive at the claimed invention. Additionally, the removal of cadmium from ores and from soils are taught as analogous endeavors in the prior art. For example, Singh’s work focuses on contaminated soil (title), but Singh further teaches it can also be applied to ores (Conclusion, ¶ 2). Ye is therefore considered analogous art to the instant invention, Benredjem, Rangarajan, and Singh.
Applicant’s arguments for the allowability of the dependent claims 4-12 and 23, rely upon claim 3 being found allowable, and are therefore not persuasive.
Pertinent Prior Art
The following prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Herman et al. (Environ. Sci. Technol. 1995, 29, 2280-2285) disclose the use of glycolipid biosurfactants (rhamnolipid) for the removal of cadmium from contaminated soil.
Conclusion
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/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735
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