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 02/25/2026 has been entered. Claims 36-49 and 53-59 are pending in this application and examined herein. Claim 36 is amended. Claims 1-35, 50-52, and 60-70 are cancelled.
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 02/25/2026 has been entered.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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 36, 46-49, 50 and 52-58 are rejected under 35 U.S.C. 103 as being unpatentable over Ji (US 20070217285 A1, cited in IDSs filed 04/13/2022 and 06/29/2023) in view of Vaarno et al. (US 20150352504 A1, cited in Office Action dated 06/02/2025).
Regarding claim 36, Ji teaches an autoclave (Title, abstract) for pressure oxidation of a slurried material comprising at least one sulfide material [0006, 0039]. Ji teaches the autoclave comprising a pressure vessel 4 for receiving said slurried material 320 (Fig. 3, [0052-0053]), the pressure vessel comprising compartments 304a-304f being arranged horizontally one after the another and separated by dividers 308a-308e (Fig. 3, [0052]), the dividers 308 a-e being provided with an upper edge that defines a level of the slurried material in the compartment. Ji teaches a sparge tube (i.e., an inlet) for feeding oxygen-containing gas 120 into the pressure vessel (Fig. 3, [0038]). Ji teaches an agitator arrangement 312a-312g for agitating said slurried material arranged in at least one of the compartments (Fig. 3, [0040]), the agitator arrangement comprising at least an upper impeller and a lower impeller (Fig. 3, [0040, 0047]), the impellers arranged in a vertically aligned shaft (Fig. 3). Ji teaches underflow openings at or below the upper impeller blades ,with the openings at least 33% and no more than 66% of height of the liquid level [0047], thus the upper impeller blades are between 33 and 66% of the height of the liquid level and the top of the tank, thus Ji teaches the upper impeller is arranged at a height above the mid-level of said one of the compartments. Ji teaches wherein the impellers pump the material to the top of the compartments [0050-0051], thus the upper impeller is an upward pumping axial flow impeller or upward pumping mixed flow impeller as claimed.
Ji does not teach wherein the gas inlet is arranged to feed oxygen-containing gas in or above the horizontal level of the upper impeller.
Vaarno teaches a stirred tank reactor (Title), for gas-liquid mass transfer in a slurry (Abstract) where the reactor 1 comprises an impeller 4 and a gas inlet 5 (Abstract), for hydrometallurgical applications [0002], thus Vaarno and Ji are analogous to the instant application as both are directed to apparatuses for mixing slurries using an agitator while adding a gas. Vaarno teaches the gas inlet 5 may be arranged below the level of the slurried material, and above the horizontal level of an upper impeller 7 (Fig. 8, [0057]).
It has long been held that it is prima facie obvious to substitute equivalents taught by the prior art to be useful for the same purpose. See MPEP 2144.06 (II). As in the instant case Ji only differs from claim 36 in that the instant claims require wherein the gas inlet is arranged to feed oxygen-containing gas below the level of the slurried material, and in or above the horizontal level of the upper impeller, and Vaarno teaches a gas inlet arranged to feed oxygen-containing gas below the level of the slurried material and above the horizontal level of the upper impeller, a prima facie case of obviousness exists as it would have been obvious to have substituted the gas inlet of Vaarno into the apparatus of Ji to inject gas into the apparatus, as gas is injected to interface with the liquid in either case.
Regarding claim 46, Ji teaches the underflow openings at 33-66% of the height of the liquid level are at the same height or below that of the upper impeller blades [0047], where the lower impeller is inherently below the upper impeller blades (e.g., Fig. 3).
Ji teaches a lower impeller arranged at a height 33-66% of the height of the liquid level (i.e., of the compartments). This overlaps the claimed range of wherein the lower impeller is arranged at a height below the mid-level (50%) of the compartments. The overlap between the ranges taught in the prior art and recited in the claims creates a prima facie case of obviousness because the prior art indicates substantial utility over the entire range disclosed therein, including that portion of the range which also falls within the claimed range. See MPEP § 2144.05(I).
Regarding claim 47, Ji teaches wherein the upper and the lower impeller are attached to the shaft [0047]. As Ji teaches the shaft to have a single rotation speed (e.g., Table 3), the upper and lower impellers are arranged to rotate with a same rotation speed.
Regarding claims 48-49, Ji does not teach wherein the diameter of the upper impeller is 0.9 - 1.4 x I, wherein I is the diameter of the lower impeller; or wherein the upper impeller has a greater diameter than the lower impeller attached to a same shaft.
It has long been held that it is prima facie obvious to make changes in the size or shape of a prior art component. See MPEP § 2144.04(IV)(A). As in the instant case Ji only differs from claims 48 and 49 in that the instant claims recite the upper impeller has certain sizes relative to the lower impeller, as Ji teaches the agitators may be any suitable impeller design [0040], a prima facie case of obviousness exists as it would have been obvious to have used impellers scaled to the claimed relative sizes.
Regarding claim 53, Ji teaches wherein the inlet is arranged to feed oxygen-containing gas 120 into the first of said compartments 304a (Fig. 3, [0038])
Regarding claim 54, Ji teaches wherein the pressure vessel is a horizontally arranged cylinder (Fig. 3, [0098]).
Regarding claim 55, Ji teaches wherein the pressure vessel comprises 5 [00055], or 6 compartments 304 a-f (i.e., at least three compartments) (Fig. 3, [0038]).
Regarding claim 56, Ji teaches comprising the agitator arrangement 312 a-g in every compartment 304 a-f (Fig. 3, [0038]).
Regarding claims 57-58, Ji teaches the agitators 312 a-g can be any suitable impeller design that efficiently promotes gas/liquid transfer and adequate mixing of the liquid or slurry feed, such as impellers manufactured by RUSHTON™ or EKATO™, where the impeller may also be a gassing impeller, such as the impeller discussed in U.S. Pat. Nos. 6,368,381 and 6,183,706, both to King, et al. [0040]. Therefore, depending on the impellers used for each agitator 312 a-g, at least one compartment in Ji will be devoid of the same agitator arrangement, and comprise a second type of agitator arrangement in the last of said components as claimed.
Claims 37-40 are rejected under 35 U.S.C. 103 as being unpatentable over Ji in view of Vaarno Gigas (US 6158722 A, cited in Office Action dated 06/02/2025).
Regarding claims 37-40, Ji in view of Vaarno does not teach wherein a distance of the upper impeller from the level of the slurried material in the at least one of said compartments is equal to or less than a diameter of said upper impeller, equal to or less than half of the diameter of said upper impeller, equal to or less than 30% of the diameter of the upper impeller, or more than 10% of the diameter of the upper impeller.
Gigas teaches a mixing system for introducing and dispersing gas into liquids (Title, abstract), where the system comprises pumping axial flow impellers 14, 16, and 18 (Abstract, Col. 3 lines 7-12), thus Ji and Gigas are both analogous to the instant application as they are both directed to systems for mixing liquids with gas comprising impellers. Gigas teaches the liquid level of liquid in the tank may be at the impeller or up to about one impeller diameter away from the surface (i.e., a distance of the upper impeller from the level of the slurried material in the at least one of said compartments is equal to 0-100% of the diameter of the upper impeller) (Col. 2 lines 37-41).
Because Ji is silent with respect to an appropriate distance from the upper impeller to the surface of the slurry, in order to carry out the invention of Ji one of ordinary skill in the art would necessarily look to the art for a reference teaching a distance suitable for the apparatus of Ji, such as taught by Gigas. As Gigas both relate to agitated reactors for mixing gas and liquid, one of ordinary skill would be motivated to use the distance from the upper impeller to the surface of the slurry of 0-100% of the diameter of the upper impeller of Gigas.
Gigas teaches a distance of the upper impeller from the level of the slurried material in the at least one of said compartments is equal 0-100% of the diameter of the upper impeller. This overlaps the claimed ranges of equal to or less than the diameter, equal to or less than half the diameter, and equal to or less than 30% of the diameter, and more than 10% of the diameter of the upper impeller. The overlap between the ranges taught in the prior art and recited in the claims creates a prima facie case of obviousness because the prior art indicates substantial utility over the entire range disclosed therein, including that portion of the range which also falls within the claimed range. See MPEP § 2144.05(I).
Claims 41-45 are rejected under 35 U.S.C. 103 as being unpatentable over Ji in view of Vaarno as applied to claim 36 above, further in view of Xia et al. (US 20150240832 A1, cited in Office Action dated 06/02/2025).
Regarding claim 41, Ji teaches the agitators 312 a-g can be any suitable impeller design that efficiently promotes gas/liquid transfer and adequate mixing of the liquid or slurry feed [0040], but does not teach wherein the upper impeller is an upward pumping axial flow impeller.
Xia teaches an axial flow impeller (Title), which may be used in metallurgical and chemical processes [0001, 0004], thus Ji and Xia are analogous as both relate to the use of impellers in metallurgical applications. Xia teaches the impeller is an axial flow impeller (Title, [0001, 0007]), where the impeller has higher pumping efficiency, and stronger axial flow with smaller power consumption and lower shear [0067].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used the axial flow impeller as taught by Xia as the upper upward pumping impeller of Ji, as doing so would result in improved pumping efficiency, and stronger flow with smaller power consumption and lower shear.
Regarding claim 42, Ji teaches the agitators 312 a-g can be any suitable impeller design that efficiently promotes gas/liquid transfer and adequate mixing of the liquid or slurry feed [0040], but does not teach wherein the upper impeller comprises at least three blades
Xia teaches an axial flow impeller (Title), which may be used in metallurgical and chemical processes [0001, 0004], thus Ji and Xia are analogous as both relate to the use of impellers in metallurgical applications. Xia teaches wherein the impeller comprises at least three blades [0017], where the impeller has higher pumping efficiency, and stronger axial flow with smaller power consumption and lower shear [0067].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used the at least three bladed impeller as taught by Xia, as the upper impeller of Ji, as doing so would result in improved pumping efficiency, and stronger flow with smaller power consumption and lower shear.
Regarding claim 43, Ji teaches the agitators 312 a-g can be any suitable impeller design that efficiently promotes gas/liquid transfer and adequate mixing of the liquid or slurry feed [0040], but does not teach wherein the blades of the upper impeller have an angle 30° - 40° with horizontal plane.
Xia teaches an impeller blade (Title), where the blade has a second angle α2 of 7-9°, and a third angle α3 of 19-25° ([0043], Fig. 5), where the pitch angle is 27-33° (i.e., wherein the blades of the impeller have an angle of 27-33° with the horizontal plane). Xia teaches the impeller provides excellent mixing performance with very low power consumption and high pumping capacity and effectiveness with the above-mentioned rules for the blade configuration [0043].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used the blade configuration with a pitch angle of 27-33° as taught by Xia for the upper impeller of Ji as doing so would provide excellent mixing performance with very low power consumption and high pumping capacity and effectiveness.
Xia teaches wherein the blades of the impeller have an angle of 27-33° with the horizontal plane. This overlaps the claimed range of 30° - 40° with horizontal plane. The overlap between the ranges taught in the prior art and recited in the claims creates a prima facie case of obviousness because the prior art indicates substantial utility over the entire range disclosed therein, including that portion of the range which also falls within the claimed range. See MPEP § 2144.05(I).
Regarding claims 44-45, Ji teaches a lower impeller [0047], and teaches wherein the lower impeller that can be any suitable impeller design that efficiently promotes gas/liquid transfer and adequate mixing of the liquid or slurry feed [0040], but does not teach wherein the lower impeller is a downward pumping axial or mixed flow impeller.
Xia teaches an axial flow impeller (Title), which may be used in metallurgical and chemical processes [0001, 0004], thus Ji and Xia are analogous as both relate to the use of impellers in metallurgical applications. Xia teaches a lower impeller 4 which is a downward pumping axial flow impeller (Title, [0001, 0007-0008], Fig. 5), where the impeller has higher pumping efficiency, and stronger axial flow with smaller power consumption and lower shear [0067].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have made the lower downward pumping impeller of Ji a downward pumping axial flow impeller as taught by Xia as the upper upward pumping impeller of Ji, as doing so would result in improved pumping efficiency, and stronger flow with smaller power consumption and lower shear.
Claim 59 is rejected under 35 U.S.C. 103 as being unpatentable over Ji and Vaarno as applied to claim 36 above, further in view of Maltby (AU 8888891 A, supplied with Office Action dated 06/02/2025).
Regarding claim 59, Ji does not teach wherein the diameter of the pressure vessel is in range of 1.5 m - 7 m.
Maltby teaches pressure oxidation methods for gold extraction (Title), where ore is pressure oxidized in autoclaves (pg. 11 line 32- pg. 12 line 10), where the slurry is agitated (pg. 13 line 11) thus Ji and Maltby are analogous to the instant application as both are directed to pressurized hydrometallurgical autoclaves under agitation. Maltby teaches the autoclave may be an industrial autoclave with a 3 m diameter (pg. 12 line 4).
Because Ji is silent with respect to a comprehensive range of appropriate diameters of the pressure vessel, in order to carry out the invention of Ji one of ordinary skill in the art would necessarily look to the art for a reference teaching autoclave diameters suitable for industrial use for the apparatus of Ji, such as that of 3 m taught by Maltby. As Ji and Maltby both relate to autoclaves comprising agitation used for hydrometallurgy, one of ordinary skill would be motivated to use the diameter of Maltby.
Response to Arguments
Applicant's arguments filed 02/25/2026 have been fully considered but they are not persuasive.
Regarding Applicant’s argument that neither of Ji or Vaarno teach an upward pumping axial flow impeller or an upward pumping mixed flow impeller (see pg. 7-9 of remarks), the Examiner respectfully disagrees.
As noted by Applicant, Ji teaches an autoclave with underflow openings at or below an uppermost impeller blade, and while Ji may indicate that the agitator initially flows primarily downwards, the Examiner notes that claim 36 does not require that the impellers be e.g., exclusively downward pumping. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Instead, instant claim 36 only require that the type of upper impeller is upward pumping axial flow or mixed flow. Ji discloses wave action is present due to the highly turbulent surface in the compartments [0013] and pronounced surface movement or turbulence induced by the agitators [0044], there must be at least some upward movement of material in compartments 304 a-d for the agitation of the impellers (located below the surface of the liquid) to affect the liquid at the surface, therefore the impellers of Ji could be considered to be “upward pumping” as claimed.
Further, even if no upward flow occurs in any of the underflowing compartments 304 a-d of Ji, compartment 304 e of Ji operates with liquid overflowing the divider 308 e (Fig. 3, [0052]), where as liquid is necessarily pumped upwards in order to overflow the divider, the agitator arrangement in at least compartment 304 e would comprise an agitator arrangement wherein the type of upper impeller is an upward pumping axial flow or mixed flow impeller as claimed.
Regarding Applicant’s argument that as Vaarno’s dispersion chamber (7) rotates, it must be considered a part of an impeller, and therefore does not teach or suggest wherein the inlet is arranged to feed oxygen-containing gas into one of the compartments containing the slurried material below the level of the slurried material (see pg. 9 of remarks), the Examiner respectfully disagrees.
While as Applicant notes, the dispersion chamber 7 surrounds an upper impeller 8 and rotates, as Vaarno teaches the dispersion chamber (i.e., a gas sparging apparatus) that feeds oxygen above the upper impeller 8, Vaarno suggests the claim as presented; as the instant application provides no special definition of what an impeller comprises or consists of (and does not e.g., prohibit the inlet to feed oxygen-containing gas rotating), and Vaarno teaches the gas sparging apparatus above what it discloses to be an impeller.
Conclusion
All claims are identical to or patentably indistinct from, or have unity of invention with claims in the application prior to the entry of the submission under 37 CFR 1.114 (that is, restriction (including a lack of unity of invention) would not be proper) and all claims could have been finally rejected on the grounds and art of record in the next Office action if they had been entered in the application prior to entry under 37 CFR 1.114. Accordingly, THIS ACTION IS MADE FINAL even though it is a first action after the filing of a request for continued examination and the submission under 37 CFR 1.114. See MPEP § 706.07(b). 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 Nikolas T Pullen whose telephone number is (571)272-1995. The examiner can normally be reached Monday - Thursday: 10:00 AM - 6:00 PM EST.
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/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/NIKOLAS TAKUYA PULLEN/Examiner, Art Unit 1733
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