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 Arguments
Applicant’s arguments, see Page 7, line 18 - Page 8, line 2 of Remarks, filed March 16th, 2026, with respect to claims 34-42 have been fully considered and are persuasive. Due to claim amendments, the rejection of claims 34-42 under 35 U.S.C. 112(b)/2nd Paragraph dated September 15th, 2025 has been withdrawn.
Applicant’s arguments, see Page 10, lines 1-5 of Remarks, filed March 16th, 2026, with respect to claims 30-49 and 54-59 have been fully considered and are persuasive. Due to the submission of a Terminal Disclaimer, the nonstatutory double patenting rejection of claims 30-49 and 54-59 dated September 15th, 2025 has been withdrawn.
Applicant’s arguments, see Page 8, line 3 - Page 9, line 30 of Remarks, filed March 16th, 2026, with respect to claims 30, 38, 43-49, and 54-57 have been fully considered but are not persuasive. Applicant argues that Lee teaches an aqueous slurry, whereas the amended claim recites a method of leaching gold from a substance comprising gold using “an organic solvent”. Applicant cites Tables 6 and 11 of the instant Specification allegedly demonstrating that organic solvents in general, and acetic acid specifically, perform better than water as a solvent. While probative, these arguments do not establish non-obviousness of the claim as recited over Lee for at least the following reasons:
The acids employed in the instant Examples contain water. Water is therefore used as a solvent in the instant invention, and the argument toward the superiority of not using water is moot.
Lee already teaches acetic acid to be a suitable acid, and thereby, solvent. Recognizing its property of being organic does not render the claim non-obvious over the prior art teaching.
In view of the foregoing, Applicant has not demonstrated unexpected results commensurate in scope with the claim to render the claim non-obvious over Lee. See MPEP 716.02(d). The rejection of claims 30, 38, 43-44, 46-49, 55-57, and 59 under 35 U.S.C. 103 over Lee and the rejection of claims 45 and 54 under 35 U.S.C. 103 over Lee in view of Wilson are maintained.
Claim Rejections - 35 USC § 103
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.
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 30, 38, 43-44, 46-49, and 55-57 are rejected under 35 U.S.C. 103 as being unpatentable over Lee (WO 0242503 A1).
Regarding claim 30, Lee teaches a method of leaching gold from a substance comprising gold (Lee, Page 3, lines 21-22, gold-bearing carbonaceous ores), the method comprising leaching the substance with a first mixture comprising:
an acid (Lee, Page 2, lines 3-7); and
an oxidizing agent (Lee, Page 4, line 18, sodium hypochlorite) to form a second mixture (Lee, Page 4, lines 18-19, slurry),
the leaching being done under conditions to leach the gold from the substance (Lee, Page 2, lines 19-20, “In the contacting or leaching step ( c ), the oxidized slurry is contacted with a
hypohalite under acidic conditions to dissolve the precious metal.”), wherein
the conditions to leach the gold from the substance comprise stirring the substance and the first mixture (Lee, Page 4, lines 6-7, mixed; Page 4-line 16, agitation is continued throughout the process) for a time of 2 to 10 hours (Lee, Page 4, lines 20-23), which overlaps with the claimed range of about 0.1 minute to about 4 hours, at a temperature of from about 40°C to about 65°C (Lee, Page 2, lines 15-17), which overlaps with the claimed range of from about 20°C to about 60°C,
the acid is a hydrogen halide (Lee, Page 2, lines 4-5, hydrochloric acid), and
the oxidizing agent is sodium hypochlorite (Lee, Page 4, line 18).
Lee does not explicitly teach that the first mixture comprises a component (c) of an organic solvent being acetic acid, as elected in response to the Election of Species requirement. However, Lee teaches generally that acetic acid can be used in combinations with other acids including hydrochloric acid for leaching (Lee, Page 2, lines 3-7, “More preferably, the acid is selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, acetic acid, phosphoric acid, hydrofluoric acid, hydrobromic acid, oxalic acid, and mixtures thereof, with mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid being most preferred.”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have selected acetic acid and hydrochloric acid as components in the first mixture, as Lee teaches that combinations from a list including these two components are suitable as an acid to dissolve precious metal values (Lee, Page 2, lines 3-8). Further, it has been held that though a specific embodiment is not taught as preferred makes it no less obvious, and that the mere fact that a reference suggests a multitude of possible combinations does not render an individual combination less obvious. See Merck v. Biocraft, 10 USPQ2d 1843 (Fed. Cir. 1985). See also MPEP 2144.08.II.
Additionally, it would have been obvious to one of ordinary skill in the art before the
effective filing date of the invention to have selected the overlapping portions of the leaching durations and temperatures because selection of overlapping portions of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Regarding claim 38, Lee renders the method of claim 30 obvious, as discussed above, wherein the method further comprises:
separating insoluble impurities from the second mixture to provide a solution of leached gold (Lee, Page 8, lines 1-4, “At the end of the leaching step, the clean pregnant liquid containing the chloro-auric complex was separated from the spent slurry by filtration, and the liquid was analyzed daily for gold for a period of two weeks.”); and
contacting the solution with a reducing agent under conditions to obtain gold (Lee, Page 9, lines 1-2, “The results show that aluminum dust is able to precipitate gold greater than 99.9% in all replicate tests.”); and
separating the gold from the solution (Lee, Fig. 1, Page 8, lines 11-14, precious metal recovery 64 to form a precious metal product 68).
Regarding claim 43, Lee renders the method of claim 30 obvious, as discussed above, wherein the first mixture further comprises a metal halide (Lee, Page 7, lines 16-19, hypohalite ions oxidize gold to form AuCl- ions, which constitute a metal halide).
Regarding claim 44, Lee renders the method of claim 30 obvious, as discussed above, wherein the substance is a gold-containing ore (Lee, Page 3, lines 21-22, gold-bearing carbonaceous ores).
Regarding claim 46, Lee renders the method of claim 30 obvious, as discussed above, wherein the solvent is acetic acid (Lee, Page 2, lines 3-7; see discussion of claim 1 above regarding obviousness of selecting acetic acid).
Regarding claim 47-48, Lee renders the method of claim 30 obvious, as discussed above, wherein the acid is HCl (Lee, Page 2, lines 3-7; see discussion of claim 1 above regarding obviousness of selecting HCl (hydrochloric acid)).
Regrading claim 49, Lee renders the method of claim 48 obvious, as discussed above, but does not explicitly teach that the acid is present in the first mixture at a concentration of from about 0.01 M to about 2.5 M. However, Lee teaches that a pH of the slurry is between 1.0 and 3.0 during an ozone treatment which occurs prior to adding sodium hypochlorite (Lee, Page 4, lines 6-10; Page 6, lines 3-17). To a first approximation, as the slurry is acidified with the acid to this range (Lee, Page 4, lines 8-10), this corresponds to a concentration of HCl of between 0.001 M and 0.1 M, which overlaps with the claimed concentration range of from about 0.01 M to about 2.5 M.
It would have been obvious to one of ordinary skill in the art before theeffective filing date of the invention to have selected the overlapping portion of the acid concentrations because selection of overlapping portions of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Regarding claim 55, Lee renders the method of claim 30 obvious, as discussed above, wherein the conditions to leach the gold from the substance comprise stirring the substance and the first mixture at a temperature of about 40°C to about 65°C (Lee, Page 4, lines 6-7, mixed; Page 4-line 16, agitation is continued throughout the process; Page 2, lines 15-17), which overlaps with the claimed range of from about 20°C to about 40°C.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the temperatures because selection of overlapping portions of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Regarding claim 56, Lee renders the method of claim 30 obvious, as discussed above, wherein separating the insoluble impurities from the second mixture comprises providing a solution of dissolved leached gold that remains in solution at room temperature (Lee, Page 8, lines 1-4, “At the end of the leaching step, the clean pregnant liquid containing the chloro-auric complex was separated from the spent slurry by filtration, and the liquid was analyzed
daily for gold for a period of two weeks.”; Page 7, lines 20-23, “Although it can be true in some applications that the hypohalite ions tend to decompose somewhat rapidly under the acidic condition, the metal complexes formed in the oxidation-reduction reaction in acid solution appear to be stable for an extended period of time.”; Page 8, lines 4-5, “The results showed that the metal complex was stable for more than a week without a noticeable degree of decomposition.”).
Regarding claim 57, Lee renders the method of claim 30 obvious, as discussed above, but does not explicitly teach that the conditions to leach the gold from the substance comprise stirring the substance and the first mixture at a temperature of about 20°C to about 25°C. However, Lee teaches generally that “I have also found that there is no noticeable decrease in the leaching efficiency even at a temperature range as low as a few degrees above the freezing point by the present acidic leaching process” (Lee, Page 7, lines 13-15).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have selected a stirring temperature of about 20°C to about 25°C in Lee’s method. The rationale to support a conclusion that the claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results to one of ordinary skill in the art (see MPEP 2143.A.). The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See KSR International Co. v. Teleflex Inc., 550 U.S. 398, 415-421, USPQ2d 1385, 1395 - 97 (2007) (see MPEP § 2143.B.). In the instant case, Lee teaches that leaching efficiency does not noticeably decrease at lower temperatures (Lee, Page 7, lines 13-15), and selecting an ambient stirring temperature, which would be about 20°C to about 25°C, would yield the predictable effect of leaching gold while obviating the need to supply external heat.
Claims 45 and 54 are rejected under 35 U.S.C. 103 as being unpatentable over Lee (WO 0242503 A1), as applied to claim 30 above, and further in view of Wilson (U.S. 4,551,213)
Regarding claims 45 and 54, Lee renders the method of claim 30 obvious as discussed above, but does not explicitly teach that the method provides a gold dissolution rate of about 500 gm-2h-1 to about 9500 gm-2h-1 (claim 45) or about 1000 gm-2h-1 to about 9500 gm-2h-1 (claim 45). However, Wilson teaches that gold dissolution rate in leaching is affected by temperature (Wilson, Col. 7, lines 61-63, “The temperature at this stage should be as high as possible to obtain a high gold dissolution rate.”).
As the leaching temperature variables that can be modified, among others, by adjusting the gold dissolution rate, with temperature both increasing/decreasing as the gold dissolution rate is increased/decreased, the precise gold dissolution rate 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 gold dissolution rate 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 gold dissolution rate in Lee’s method to obtain the desired leaching temperature as taught by Wilson (Wilson, Col. 7, lines 61-63) (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223). “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.).
Allowable Subject Matter
Claims 31-37, 39-42, and 58 would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: Lee (WO 02/42503 A), ‘151 (U.S. 2012/0228151), Miettinen (WO 2014/177765 A1), and Wilson (U.S. 4,551,213) are considered to be the closest prior art to the instant claims.
Regarding claim 31 and its dependent claims 32-37, Lee renders the method of claim 30 obvious, as discussed above, Lee renders the method of claim 30 obvious, as discussed above, wherein the method further comprises separating insoluble impurities from the second mixture to provide a solution of leached gold (Lee, Page 8, lines 1-4, “At the end of the leaching step, the clean pregnant liquid containing the chloro-auric complex was separated from the spent slurry by filtration, and the liquid was analyzed daily for gold for a period of two weeks.”). However, Lee does not teach or suggest evaporating the solution to provide the leached gold. Rather, Lee teaches that the leached gold can be recovered “by any of those conventional techniques such as carbon-in-leach (CIL), carbon-in-pulp (CIP), or Merrill-Crowe precipitation process using zinc or aluminum” (Lee, Page 4, line 23 – Page 5, line 2). None of these techniques would entail evaporating the solution to provide the leached gold. Where the leach solution is evaporated in the prior art, it is done in processes that do not provide the leached gold. For example, in Miettinen, the leach solution is evaporated after separating the leached gold to remove and reuse Cl- ions and to improve environmental sustainability (Miettinen, Page 11, lines 30-34; Page 18, lines 23-26). As none of the cited prior art references teach or suggest evaporating the solution of leached gold to provide the leached gold, the claim is neither anticipated nor rendered obvious by the cited prior art.
Regarding claim 39 and its dependent claims 40-42, Lee renders the method of claim 38 obvious, as discussed above, but does not teach or suggest that the method further comprises, after separating the gold from the solution, dissolving the gold in aqua regia and contacting the dissolved gold with a compound of Formula I. ‘151 appears to teach separating gold from an acidic leachate into an organic phase using an extractant having Formula I(a)(iv) as claimed in claim 34 (‘151, [0045], dicyclohexyl carbodiimide, morpholine amine, CS2; [0053]). However, as Lee already teaches that gold can be essentially isolated by precipitation (Lee, Page 9, lines 1-2, “The results show that aluminum dust is able to precipitate gold greater than 99.9% in all replicate tests.”), there would be no reason to undergo the liquid-liquid extraction of ‘151 to separate the gold from “very high levels of other impurities” (‘151, [0053]), and it would therefore not be obvious to re-dissolve the gold to contact the gold with an extractant having the claimed Formula I.
Regarding claim 58, Lee renders the method of claim 30 obvious, as discussed above, wherein the first mixture comprises about 50 to 80% (w/w) water (Lee, Page 5, lines 15-16, “The density of aqueous slurry 24 normally comprises from 20 to 50 weight percent solids.” As an aqueous slurry having dilute acid and oxidant components, the weight percentage of water would not deviate substantially from values obtained by subtracting the solids content from the total.), which differs from the claimed range of less than, or equal to, about 17% (w/w) water. As none of the cited prior art references teach a water content this low, the claim is neither anticipated nor rendered obvious by the cited prior art.
Conclusion
THIS ACTION IS MADE FINAL. 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 ZACHARY J. BAUM whose telephone number is (571)270-0895. The examiner can normally be reached Monday-Friday 8:30-5:00.
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/ZACHARY JOHN BAUM/Examiner, Art Unit 1736
/ANTHONY J ZIMMER/Supervisory Patent Examiner, Art Unit 1736