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.
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-10, in the reply filed on 29 October 2025 is acknowledged.
Claims 11 and 12 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 29 October 2025.
Specification
The disclosure is objected to because of the following informalities:
Page 1, lines 25-26: the chemical formulas should have their numbers subscripted.
Page 12, line 4: the pH range is listed as -9.0 to 11.0, whereas it is likely meant to read as 9.0 to 11.0.
Page 12, line 11: the preferable temperature range should read 700 °C to 800 °C, and not 8000 °C.
Pages 14-16: Examples 2-6, 8, and 10 recite a “grade A” iron powder and reference “the details below.” However, no details of this powder could be found in the specification; the reference to such details should be removed.
Appropriate correction is required.
Applicant is advised to check the specification for additional typographical errors.
Claim Interpretation
Claim 4 ends with the limitation “which will magnetize,” but there is no object to the verb magnetize provided. Accordingly, this limitation will be interpreted broadly, and the separator causing any material to be magnetized to any degree for any duration will meet the limitations of the claim.
Claim Objections
Claims 1, 4, 5, and 7 are objected to because of the following informalities:
Claim 1, line 5: “… in an oven at a [[temperatures]] temperature …”
Claim 1, line 6: “…and further crushing the dried red mud powder [[is crushed]] to fine particles;”
Claim 1, line 10: “…[[was]] is done by…”
Claim 4, lines 1-2: “ the magnetization [[was]] is carried out by passing [[passed]] through…”
Claim 5, line 1: “…also induces [[induce]]…”
Claim 7, line 1: “…facilitates [[to change]] changing the structure of the red mud[[,]] and…”
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 2, 3, 4, 6, 9, and 10 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claims 2 and 3, a broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claims 2 recites the broad recitation of 100 nm-1000 nm, and the claim also recites “preferably 100-300 nm” which is the narrower statement of the range/limitation; claims 3 recites the broad recitation of 400-1000 °C, and the claim also recites “the preferable temperature is 600-700°C” which is the narrower statement of the range/limitation. The claims are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims. For the purposes of further examination, the preferable ranges will be treated as optional.
Claim 4 recites the limitation "the strong magnetic field" in line 3. There is insufficient antecedent basis for this limitation in the claim. Additionally, the term “strong magnetic field” in this claim is a relative term which renders the claim indefinite. The term “strong” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. It is therefore indefinite what strength of magnetic field is required to meet the limitations of the claim.
Claim 4 further recites the limitation "the magnetization" in line 1. However, the antecedent basis for this limitation is unclear. While claim 1 recites “magnetizing the ferric oxide,” this is completed in a separate step than the step requiring the magnetic separator, which itself does not recite any magnetization. For the purposes of further examination, “the magnetization” of claim 4 will be interpreted as any magnetization that occurs while passing through the magnetic separator.
The metes and bounds of claim 6 are also unclear because the claim recites a frequency range of from 50-1000 Hz, and then a preferred frequency of 800 kHz, equivalent to 800,000 Hz, which lies well outside the first range recited. It is further noted that Examples 2-5 and 10 in the specification recite 800 Hz as the frequency used, while p. 10 lines 10-13 again recites first a range of 50-1000 Hz as the frequencies that can be used, and then gives an ideal range of 700-800 kHz, which lies outside the first range given. In short, no clarity is provided by the specification as to whether the range of frequencies to be used is in the range of hundreds of hertz or hundreds of kHz. For the purposes of further examination, either frequency range will be considered as meeting the limitations of the claim.
Claim 6 is further indefinite because the magnetic field power of the magnetic separator recited in the claim follows the “preferred range” construction, and therefore it is unclear if this field power represents a required limitation or merely a preferred and optional limitation of the claim.
Claims 9 and 10 each recite the limitation “the treated red mud” in line 1. However, the antecedent basis for this limitation is unclear because there is no recitation of “treated red mud” in the claims or in claim 1, upon which they depend. For the purposes of further examination, “the treated red mud” will be interpreted as referring to the red mud obtained after treating the dried red mud with various iron nanoparticles in the method of claim 1.
Claim 9 further recites the limitation “wherein the treated red mud …shows a higher percentage of total iron content,” but it is unclear what percentage of total iron content that of the treated red mud is being compared to. For the purposes of further examination the percentage of the total iron content in the treated red mud will be compared to the percentage of total iron content in the red mud before treatments with iron nanoparticles.
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 1, 3, and 5-10 are rejected under 35 U.S.C. 103 as being unpatentable over Amiran (US 2017/0320751) in view of Kozéky et al. (US 2020/0299806 A1), Tanvar et al. (US 2022/0185688 A1; published 16 June 2022; effective filing date 10 December 2020) and Li et al. (Trans. Nonferrous Met. Soc. China 2015, 25, 3467−3474).
Regarding claim 1, Amiran teaches a method of processing red mud (RM) for the recovery of iron values (recovering magnetite from bauxite residue; abstract) comprising:
neutralizing the red mud with acid (catalyst plus neutralizing solution is used to reduce the pH of the Red Mud from its typical range of 12-13 into a range of about 4-9, preferably about 7; [0040]);
drying the red mud in an oven at a temperature of 40-90 °C (100 °F to 200 °F; [0041]), which overlaps with the instantly claimed range of 80-1000 C, and further crushing the dried red mud powder to fine particles (Red Mud/coke mixture is then pulverized; [0042]); and
separating the magnetic material from the non-magnetic material in the treated red mud by a magnetic separator (the synthetic Fe3O4 magnetite may be separated from the mixture using a magnetic separator; [0047]).
Amiran further teaches that coke can be introduced to serve as the reductant, via formation of CO, to reduce Fe2O3 to Fe3O4 ([0036]) and that smaller particle sizes in a red mud/coke mixture would be expected to increase yield and rate of reaction ([0042]).
Amiran does not teach a filtration process to remove the dissolved salts from the red mud slurry, is silent on the drying time used, and does not teach treating the dried red mud powder with various iron nanoparticles so that the iron oxides (Fe2O3 and α-FeOOH) in the red mud are converted into magnetite (synthetic Fe3O4), wherein magnetizing the ferric oxide present in the red mud was done by selective heating of iron nanoparticles mixed with red mud using inductive heating technology. Amiran is likewise silent on how the magnetic separator works and if it utilizes magnetic induction.
However, Tanvar also teaches a red mud (bauxite residue) treatment process to recover magnetite and that an initial neutralization by acid washing makes the red mud more amenable to subsequent metal recovery steps (abstract and Fig. 3). Tanvar further teaches that this acid wash is carried out by treating with mild hydrochloric acid to form a slurry followed by filtration to obtain neutralized red mud ([0022]). Such a filtration process will necessarily remove dissolved salts.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to filter the neutralized red mud in the method of Amiran to remove dissolved salts, as taught by Tanvar. One of ordinary skill in the art would have been motivated to do so because Tanvar teaches that this process makes the red mud more amenable to subsequent metal recovery steps, which is the same goal of Amiran.
Furthermore, Li also investigates the reduction of ferric oxide to magnetite in red mud (bauxite residue) and teaches that iron powder can serve as the reductant in the reduction of ferric oxide in red mud (iron powder as the reductant is able to convert the iron minerals in bauxite to magnetite; p. 3473, col. 1, ¶ 1).
Regarding the limitation that the iron used to treat the red mud be in the form of iron nanoparticles, it is again noted that Amiran teaches that smaller particle sizes increase reaction rate and yield. Accordingly, iron powders comprised of nanoparticles would be expected to have higher rates of reaction than iron powders comprised of larger particles. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use iron nanoparticles in place of the coke used in the method of Amiran. One of ordinary skill in the art would have been motivated to do so because Li teaches that iron can serve as the reductant in this reaction, and because Amiran teaches that smaller particles result in higher yields and reaction rates.
Additionally, Kozéky also teaches a method for processing red mud comprising converting Fe2O3 to Fe3O4 (magnetite) and separating the magnetite by magnetic separator (abstract). Kozéky further teaches magnetizing the ferric oxide present in the red mud by heating using inductive heating technology (the red mud prepared is magnetized by heating in an induction furnace…, which is suitable for magnetizing the paramagnetic hematite in the iron oxide Fe2O3; [0084]), as well as that this is the preferred heating technique ([0085]). Kozéky also teaches that utilizing a magnetic separator that operates according to the principle of magnetic induction is preferred ([0087]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to heat the red mud in the method of modified Amiran using inductive heating technology and to utilize a magnetic separator which works on the principle of magnetic induction, as taught by Kozéky. One of ordinary skill in the art would have been motivated to use inductive heating technology because Kozéky teaches that this the preferred heating technique and the preferred type of magnetic separator. Inductive heating would necessarily cause localized heating around the magnetic iron nanoparticles.
Regarding the drying time, while Amiran does not teach how long to dry the red mud following neutralization, they do teach a desired moisture content as well as a range of temperatures and suggest drying under partial to increase the drying rate ([0041]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the drying rate and therefore time required to achieve the desired level of moisture content, as taught by Amiran, thereby arriving at the instantly claimed invention.
The courts have found 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.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 II. Therefore, the claimed ranges of drying time merely represent an obvious variant and/or routine optimization of the drying operation taught by Amiran.
Regarding claim 3, modified Amiran teaches the method of claim 1, where Amiran teaches that the reduction of iron oxides to magnetite at a temperature of 700 to 1100 °C ([0043]), which overlaps with the instantly claimed range of 400 °C to 1000 °C.
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01).
It is further noted that generally, differences in temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such a temperature is critical. "[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 MPEP 2144.05 and In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Regarding claim 5, modified Amiran teaches the method of claim 1, where Kozéky teaches that the induction furnaces induces an alternating frequency magnetic field which is suitable for magnetizing the paramagnetic hematite to a magnetic state ([0084]).
Regarding claim 6, modified Amiran teaches the method of claim 1, where Kozéky teaches performing the magnetic heating with a voltage of 380 V, ideally a 1000 Hz alternating frequency, and a magnetic separator having about a 1 Tesla magnetic field power ([0086]), each of which lie in the instantly claimed ranges.
Regarding claim 7, modified Amiran teaches the method of claim 1, where Kozéky teaches that the induction heating facilitates changing the structure of the red mud, pre-magnetizing the originally paramagnetic hematite particles by its induced magnetic field in order to bring the hematite particles to a magnetic state ([0085]).
Regarding claim 8, modified Amiran teaches the method of claim 1, where the product form of the iron is synthetic magnetite, which is a black powder-like material that is widely used as a pigment in industrial manufacturing applications including high-temperature composite materials, coatings, acrylic and oil-based paints, plastics, and other polymer resins, as well as being used in adding color to various types of metallic surfaces ([0019]). Amiran further teaches that their process is capable of extracting 80-90% of the iron red mud ([0019]), which means that it is also capable of extracting less of the iron. Furthermore, the modifications to the process of Amiran taught by Tanvar, Kozéky, and Li lead us to a method that is substantially similar to the process instantly claimed, and therefore is expected to give the same, or substantially similar extraction efficiency.
Regarding claim 9, modified Amiran teaches the method of claim 1, where Li teaches a treatment wherein iron is added to the red mud as the reductant for converting goethite and hematite (Hematite, goethite, magnetite, etc., are the common iron minerals in bauxite; p. 3468, col. 2, ¶ 4) to magnetite (iron powder as the reductant is able to convert the iron minerals in bauxite to magnetite; p. 3473, col. 1, ¶ 1). Because the language of claim 9 is indefinite (see Claim Rejections – 35 USC § 112), the claim is interpreted as requiring the treated red mud to show a higher percentage of total iron content than the red mud before treatment. Under this interpretation, because Li teaches a treatment that adds pure iron to a mixture that is less than 100% iron (red mud), the treatment will necessarily increase the total iron content of the red mud, and therefore meet the limitations of claim 9.
Regarding claim 10, modified Amiran teaches the method of claim 1, where Li further teaches washing the red mud with hot water after treatment with iron powder (the obtained slurry was subsequently filtered and the filter cake was washed with hot water, p. 3468, spanning col. 1 and 2). A washing and filtration will remove soluble salts, and hot water will have a temperature between room temperature and 100 °C.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to wash the treated red mud in the method of modified Amiran with hot water, as taught by Li. One of ordinary skill in the art would have been motivated to add the washing step of Li because Li teaches that such a washing is appropriate after treatment with iron powder.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Amiran (US 2017/0320751) in view of Kozéky et al. (US 2020/0299806 A1), Tanvar et al. (US 2022/0185688 A1; published 16 June 2022; effective filing date 10 December 2020) and Li et al. (Trans. Nonferrous Met. Soc. China 2015, 25, 3467−3474), as applied to claim 1 above, and further in view of Lumsden et al. (US 2019/0218119 A1).
Regarding claim 2, modified Amiran teaches the method of claim 1, but does not teach the size of the iron nanoparticles to be used in treating the red mud.
However, Lumsden teaches a method of preparing zero-valent iron nanoparticles which can be used for environmental remediation from acid-mine drainage (abstract), and further teaches that these nanoparticles have sizes in the range of 100 nm–300 nm ([0033]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the nanoparticles of Lumsden with sizes of 100 nm-300 nm in the method of Amiran, thereby arriving at the instantly claimed invention. One of ordinary skill in the art would have been motivated to do so because Lumsden teaches that such nanoparticles can be used for environmental remediation, of which red mud processing is one example. One of ordinary skill in the art would have been further motivated to do so because nanoparticles of this size can be made from acid mine drainage which helps to ameliorate the environmental impact of this material, as taught by Lumsden ([0009]).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Amiran (US 2017/0320751) in view of Kozéky et al. (US 2020/0299806 A1), Tanvar et al. (US 2022/0185688 A1; published 16 June 2022; effective filing date 10 December 2020) and Li et al. (Trans. Nonferrous Met. Soc. China 2015, 25, 3467−3474), as applied to claim 1 above, and further in view of Zou (CN 102989578 A). The provided English machine translation of Zou (CN 102989578 A) is referenced in the analysis below.
Regarding claim 4, modified Amiran teaches the method of claim 1, where Amiran teaches passing the red mud through a magnetic separator, as analyzed above. Kozéky teaches that such a separator will magnetize the material that passes through it (same device design as that of the device with the magnetizing function; [0087]). Amiran only teaches one magnetic separator and not two magnetic separators connected in series.
However, Zou also teaches a method for the magnetic separation of red mud ([0003]) and further teaches that it is environmentally friendly and low cost to use a magnetic separation where the red mud passed through two magnetic separators connected in series, wherein the first magnetic separator provides a strong magnetic field ([0008]-[0009]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to pass the red mud of Amiran through two magnetic separators connected in series where the first magnetic separator provides a strong magnetic field, as taught by Zou, where Kozéky teaches that such a magnetic separator will magnetize materials in the red mud. One of ordinary skill in the art would have been motivated to use two magnetic separators because Zou teaches this method is able to afford separation of different ores in the red mud ([0015]) in a simple process that does not require complicated equipment, and thereby reduces the cost of mineral processing in red mud ([0016]).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Nicholas A Piro whose telephone number is (571)272-6344. The examiner can normally be reached Mon-Fri, 8:00 am-5:00 pm.
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, Sally Merkling can be reached at (571) 272-6297. 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.
/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735