NON-FINAL 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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 23 April 2026 has been entered.
Priority
Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged.
Response to Arguments
Applicant's arguments filed 3 April 2026 have been fully considered. The arguments are persuasive with respect to claims 1-18 and 21-24, and said claims are allowed. The arguments are not persuasive with respect to claim 20, which remains rejected under 35 U.S.C.§103 as discussed in the rejections below.
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.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Venkatachari et al. (U.S. Statutory Invention Registration H981, hereinafter Venkatachari) in view of Breerwood (U.S. Patent No. 2,214,717).
Regarding claim 20, Venkatachari discloses a system for classification and recovery, comprising: a first solid bowl centrifuge (20; Fig. 1) configured to process a first stream (coal water slurry; Abstract) comprising a first plurality of solids at a first cut-off particle size, and wherein a first portion (centrifuge cake; Abstract) of the first plurality of solids has sizes greater than the first cut-off particle size, and a second portion (centrate; Abstract) of the first plurality of solids has sizes less than or equal to the first cut-off particle size, and wherein the first cut-off particle size is from about 5 µm to about 100 µm (approximately 20 micron size; col. 6 lines 37-38); optionally a second solid bowl centrifuge (the classifier cake is re-ground and mixed with fresh feed to the solid bowl centrifuge for additional classification, Abstract). Venkatachari further discloses that the centrate is transported to a suitable cleaning facility which will separate the tailings from the clean coal (col. 4 lines 8-11) and that the separation step may be accomplished by specific gravity separation, froth flotation methods or by agglomeration methods which are known (col. 1 lines 59-62), but does not explicitly teach a valorization apparatus configured to receive the centrifuge cake or centrate.
Breerwood discloses a valorization apparatus in the form of a froth flotation device (froth flotation was carried out in a stage-oiling rougher circuit, page 5 right column lines 49-67; froth flotation in a laboratory Fagergren flotation machine, page 8 right column lines 4-7), wherein the valorization apparatus is configured to receive a first cake (centrifuge cake; page 5 right column lines 49-59). It would have been obvious for one having ordinary skill in the art before the effective filing date of the claimed invention to combine the classification system of Venkatachari with the valorization apparatus of Breerwood for the purpose of recovering the useful constituent or constituents from the centrifuge output (page 4, left column, lines 35-55, Breerwood).
With respect to the limitation wherein “the material of interest consists of a phosphorus-containing compound, a native metal, a metal-containing compound, a mineral, or a combination thereof”, such limitation specifies the composition of the material processed by the system, and does not structurally distinguish the claimed apparatus from the prior art apparatus. It has been held that "[i]nclusion of the materials or article worked upon by a structure being claimed does not impart patentability to the claims." In re Otto, 312 F.2d 937, 136 USPW 458, 459 (CCPA 1963); see also In re Young, 75 F.2d 996, 25 USPC 69 (CCPS). See MPEP 2115. The structure of the solid bowl centrifuge of Venkatachari would not change based on the composition of the feed material. The limitation “with the proviso that the material of interest does not include calcium carbonate” similarly does not structurally distinguish the claimed apparatus for the same reasons.
Claim 20 additionally recites that the first solid bowl centrifuge is configured to process a first stream “wherein the first cut-off particle size is from about 5 µm to about 100 µm.” This limitation describes an operational parameter rather than any structural feature of the apparatus itself. A centrifuge’s cut-off particle size is not a fixed structural feature of the centrifuge, but is determined by operating conditions (e.g., rotational speed, feed rate, feed properties, etc.). The same centrifuge can be operated at different operating parameters to achieve a different cut-off particle size without structurally modifying the centrifuge. Nevertheless, Venkatachari teaches a cut-off particle size of approximately 20 microns (col. 6 lines 37-38), which is within the claimed range of about 5 µm to about 100 µm.
Claim 20 also recites that the valorization apparatus is “configured to recover in the first cake, the second cake, the diluted first cake, or the diluted second cake at least 5%, by weight, more of the material of interest that is present in the first stream than an identical valorization procedure performed directly on the first stream.” However, this limitation describes what the apparatus achieves when operated under certain operating conditions, not any structural feature of the valorization apparatus. The froth flotation apparatus of Breerwood meets the recited structure of the claimed valorization apparatus regardless of whether a 5% recovery improvement is achieved for a given operation. As held in In re Casey, 370 F.2d 576, 152 USPQ 235 (CCPA 1967), "the manner or method in which such machine is to be utilized is not germane to the issue of patentability of the machine itself." See MPEP 2115. While features of an apparatus may be recited either structurally or functionally, claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function. In re Schreiber, 128 F.3d 1473, 1477-78, 44 USPQ2d 1429, 1431-32 (Fed. Cir. 1997) (The absence of a disclosure in a prior art reference relating to function did not defeat the Board’s finding of anticipation of claimed apparatus because the limitations at issue were found to be inherent in the prior art reference); see also In re Swinehart, 439 F.2d 210, 212-13, 169 USPQ 226, 228-29 (CCPA 1971); In re Danly, 263 F.2d 844, 847, 120 USPQ 528, 531 (CCPA 1959). “[A]pparatus claims cover what a device is, not what a device does.” Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original). Nevertheless, Breerwood shows that the centrifuge cake already achieves a material of interest content of 75% compared to the feed content of 67.5% (page 5, right column, lines 43-48), which demonstrates that centrifuge pre-classification inherently enriches the material for downstream recovery. The valorization apparatus of Breerwood is therefore inherently capable of achieving the recited recovery improvement.
Allowable Subject Matter
Claims 1-18 and 21-24 are allowable, because the prior art does not teach or suggest the claimed method as a whole. In particular, Venkatachari discloses a solid bowl centrifuge at approximately 20 microns (col. 6 lines 37-38) and a downstream cleaning facility as a valorization step (col. 4, lines 8-11), but is directed to the recovery of coal for use as a fuel (Abstract). Coal is not within the closed Markush group of the “consists of” limitation, and Venkatachari’s valorization procedure recovers coal, which is not a recited material of interest. Breerwood discloses solid bowl centrifuge classification at 2-50µm cut-off sizes followed by froth flotation of the classified fraction, with an improvement in recovery of the material of interest over direct flotation on the unclassified feed (page 5, right column, lines 43-48; page 6, left column, lines 17-25). However, the material of interest in Breerwood is calcite/calcium carbonate, which is explicitly excluded from claim 1. Accordingly, the “consists of” material of interest limitations, the at least 5% by weight valorization recovery improvement, and the method taken as a whole, is not taught or suggested by the references or combination of references of record.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHUYI S LIU whose telephone number is (571)272-0496. The examiner can normally be reached MON - FRI 9:30AM - 2:30PM EST.
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, Claire Wang can be reached at 571-270-1051. 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.
/Shuyi S. Liu/ Examiner, Art Unit 1774
Prosecution Insights