DETAILED ACTION
Status of Claims
Claims 1-4, 6-15, 18, and 19 are pending. Of the pending claims, claims 1-4, 6-15, and 18 are presented for examination on the merits, and claim 19 is withdrawn from examination.
Status of Previous Objections to the Drawings
The previous objections to the drawings are withdrawn in view of the amendments to the specification filed on 03/17/2026.
Status of Previous Claim Rejections Under 35 USC § 112
The previous rejection of claim 18 under 35 U.S.C. § 112(b) is withdrawn in view of the amendment to the claim.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-4, 6-15, and 18 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Regarding claim 1, the limitation “for metallothermic reduction” is new matter because the specification as originally filed does not contain this term. Applicant appears to suggest that metallothermic reduction excludes electrolytic reduction. However, there is no basis for such a suggestion. The present disclosure provides no substantive limitations regarding limits on how the reduction is executed. For instance, the claim 1 merely recites that reduction take place in a cell (line 3) without specifying any structure or excluding the presence of electrodes. Furthermore, the claims do not recite any step that would inherently or explicitly exclude the use of an electrolytic cell. Thus, the claims and specification lack support for the term “metallothermic reduction.”
Regarding claims 2-4, 6-15, and 18, the claims are likewise rejected, as they incorporate the limitations of rejected claim 1.
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.
Claims 1-4, 6-11, 15, and 18 are rejected under 35 U.S.C. 103 as being unpatentable over US 6,117,208 (A) to Sharma (“Sharma”) in view of KR 10-1878652 (B1) to Lee et al. (“Lee”) (abstract and computer-generated translation are on file as of 12/23/2025).
Regarding claim 1, Sharma discloses a method in which titanium or zirconium dioxide is reduced to titanium or zirconium metal (reducing M1 metal from metal oxide). Col. 1, lines 4-7. The method includes the following steps (FIG. 1):
(a) putting salt components into a vessel to create a molten salt bath containing CaF2 (forming a molten salt of a fluoride-based flux in a cell) (col. 6, lines 16-21);
(b) melting Zn (M2) and Ca (M3) in the vessel to product Ca-Zn composition (putting into the cell a metal M2 and reducing agent including metal M3 to produce a composition of metal M2 and metal M3 (col. 5, lines 1-4; col. 6, lines 14-16);
(c) adding TiO2 (M1 metal oxide) so that it is reduced by at least the Ca (M3), which is in the Zn-Ca (M2-M3 alloy) (col. 6, lines 20-31); and
(d) forming a melt of Zn-Ti (forming liquid metal alloy with reduced M1 and M2) (col. 5, lines 10-15).
The molten salt is far lighter than the metallic pool (density of molten salt being less than density of metal oxide and metal/metal alloy formed). Col. 5, lines 12-15.
Sharma does not teaches using a vessel, not an electrolytic cell, to carry out the reaction (metallothermic reduction). Col. 5, lines 45-67; col. 6, lines 1-6.
Sharma discloses the formation of Ca-Zn (M3-M2 alloy) melt, the composition of which can be selected using a phase diagram (col. 5, lines 1-4), as well as the formation of a Zn-Ti melt (M2-M1 alloy), but does not specify a eutectic composition.
Lee is directed to a method of producing a metal from a metal oxide. Abstract; para. [0006]. Lee discloses providing a second metal (M2) that forms a eutectic alloy with a third metal (M3). Para. [0100], [0103], [0113], [0115]. The second metal is such that it can form a eutectic alloy with the first metal (metal M2 forming a eutectic phase with the metal M1). Para. [0102], [0113], [0115]. Eutectic compositions have a low melting point, enabling the reaction to take place at lower temperatures. Para. [0044], [0045].
It would have been obvious to have selected the eutectic compositions of the Ca-Zn and Zn-Ti alloys because it would cause the reduction process to require less energy consumption.
Regarding claim 2, Sharma is silent regarding the volatilization rate of the molten salt.
Lee discloses that it is desirable to use a salt with a higher boiling point as the electrolyte so that the salt is stable at the process temperature and separation is facilitated. Para. [0063], [0112].
Therefore, it would have been obvious to one of ordinary skill in the art to have selected the particular makeup of the molten salt of Sharma to have a high boiling point, such as the low volatilization rate claimed, in order to maintain the stability of the salt during reaction.
Regarding claims 3 and 4, Sharma discloses that the salt bath contains calcium fluoride (CaF2) (molten salt contains fluoride-based flux such as CaF2). Col. 4, lines 8-11, 37-61; FIG. 1.
Regarding claim 6, Sharma discloses that zinc is added, with cadmium being an alternative (M2 is Zn or Cd). Col. 4, lines 15-19; col. 6, lines 14-16; FIG. 1.
Regarding claim 7, Sharma discloses that the zinc may be Cd (M2 is Zn or Cd) (col. 4, lines 15-19; col. 6, lines 14-16; FIG. 1), but does not disclose Cu.
Lee discloses that the second metal (M2) can be one or more of Cu, Sn, Zn, Pb, Bi, and Cd. Para. [0116].
It has been held that it is obvious to substitute or combine equivalents known in the art. See MPEP § 2144.06. Since Cu is a known equivalent of Zn and Cd in the reduction of metal oxides, it would have been obvious to one of ordinary skill in the art to have replaced or combine it with the Zn and/or Cd of Sharma for the purpose of alloying with and the collection of Ti or Zr.
Regarding claim 8, Sharma discloses adding Ca (M3 is Ca). Col. 4, lines 19-24; col. 5, lines 42-43; col. 6, lines 14-16; FIG. 1.
Regarding claim 9, Sharma discloses that the starting material may be titanium dioxide (TiO2) or zirconium dioxide (ZrO2) (M1 is Ti or Zr; x = 1, y = 2). Col. 1, lines 4-7; col. 7, lines 3-5.
Regarding claim 10, Sharma discloses that the reducing reaction in a salt bath, which contains a fluoride. Col. 6, lines 20-21; FIG. 1.
Regarding claim 11, Sharma discloses that the temperature is maintained at about 800°C to 900°C when the oxide is reduced. Col. 6, lines 20-26.
Regarding claim 15, Sharma discloses that Ti is separated from the Zn by electrochemical technique, e.g., electrolytic process (electrorefining the liquid metal alloy to produce M1 metal). Col. 4, lines 24-26; col. 5, lines 15-19; col. 6, lines 60-63; FIG. 1.
Regarding claim 18, Sharma discloses that the ultimate oxygen content is 0.1-0.3% (1000-3000 ppm). Col. 4, lines 34-37. The Ca (M3) is totally consumed, and the titanium is substantially pure (col. 6, lines 58-60; claim 1), suggesting low or minimized amount of M3 element.
Claims 12 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Sharma in view of Lee, as applied to claim 1 above, and further in view of US 5,152,830 (A) to Kobayashi et al. (“Kobayashi”).
Regarding claims 12 and 13, Sharma discloses the formation of CaO (col. 4, lines 27-30, 39-40; col. 6, lines 57-58), but does not teach forming slag by adding a slag-forming additive.
Kobayashi is directed to a process of producing pure metal or alloy by reacting metallic oxide with a reducing agent. Abstract; col. 2, lines 54-58. The reducing agent may be aluminum or aluminum partially replaced by another reducing agent, such as silicon, calcium, or magnesium. Col. 5, lines 30-34. Upon completion of the reaction, the metallic oxide is reduced, and a slag comprising oxides of the reducing agent and the targeted metal is produced. Col. 3, lines 50-68.
The metal and the slag should be separated quickly and as soon as possible in order to obtain a metal of high purity concentration. Col. 4, lines 1-9. To aid the process, a slag forming material is added for the purpose of lowering the melting point of the slag. Col. 5, lines 35-45. Example slag forming materials include quick lime (CaO) and magnesia (MgO).
An objective of Sharma is to produce a high-purity metal. Col. 4, lines 41-42. Thus, it would have been obvious to one of ordinary skill in the art to have added a slag forming material, as taught by Kobayashi, to the process of Sharma in view of Lee because the slag forming material would facilitate the removal of the reaction by-products, thereby ensuring that the obtained metal alloy remains as pure as possible.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Sharma in view of Lee and Kobayashi, as applied to claim 12 above, and further in view of US 1,730,775 (A) to Lukens et al. (“Lukens”).
Regarding claim 14, Sharma discloses that molten Zn-Ti (liquid metal alloy M2M1) and intermetallic compound is formed, the latter being lighter than the Zn-Ti and being embedded in the upper portion of the pool below the salt phase (thus, the liquid metal alloy is at the bottom of the reaction vessel).
Kobayashi discloses that separation of slag and metal occurs due to their difference in specific gravity (forming distinct layer on top of the eutectic composition using the slags). Col. 4, lines 1-4.
Sharma does not teach continuous removal of the liquid metal alloy through a lower portion of the cell and continuous removal of slags through a top of the cell.
Lukens is directed to a the deoxidation of molten copper. Page 1, lines 1-8. The apparatus used to carry out the process includes a refractory (19) (cell) containing slag (16), a slag exit (upper right), copper metal underneath the slag, and spout (18). FIG.9. Another example apparatus shows slag exit (upper left), reduced metal (30), and metal exit (lower right). FIG. 10; FIG. 11. The copper may be discharged continuously. Page 3, lines 13-18. The slag can be removed continuously. Page 3, lines 125-130; page 4, lines 1-2, 24-30.
Kobayashi teaches that the metal and the slag should be separated quickly and as soon as possible in order to obtain a metal of high purity concentration. Col. 4, lines 1-9. Therefore, it would have been obvious to one of ordinary skill in the art to have incorporated the continuous removal of metal and slag via spouts and exits, as taught by Lukens, in the process of Sharma in view of Lee because the continuous removal of the reduced metal would preserve its purity and the continuous removal of slag would allow it to be treated or reused, as needed.
Response to Arguments
Applicant’s arguments with respect to Lee have been considered but are moot because the new ground of rejection relies on a new combination of references.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 VANESSA T. LUK whose telephone number is (571)270-3587. The examiner can normally be reached Monday-Friday 9:30 AM - 4:30 PM ET.
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/VANESSA T. LUK/Primary Examiner, Art Unit 1733
May 31, 2026
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