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 .
Priority
Receipt is acknowledged of a certified copy of CN 201911302508.6 filed December 17, 2019 as required by 37 CFR 1.55. Receipt is also acknowledged of WO 2021/121312, a copy of the WIPO publication of PCT/CN 2020/137175 filed December 17, 2020.
Claim Status
This Office Action is in response to Applicant’s Remarks and Claim Amendments filed January 26, 2026.
Claims Filing Date
January 26, 2026
Amended
1
Cancelled
2
Withdrawn
10-54
Under Examination
1, 3-9
The applicant argues support for amended claim 1 at p. 15 (Remarks p. 17 para. 4).
Applicant’s p. 15 recites controlling a pressure P to be at least 1000 Pa and a reaction temperature higher than Curve (2) and Curve (4) and lower than Curve (5) of applicant’s Fig 1 to “ensure…the subsequent reaction of the resulting Ca vapor with C. As a result, CaC2 is produced, and the vapor will not be just lost.”
Further, applicant’s p. 19 recites “(2) If the temperature is in the range of 30lg2P + 58lgP + 1215 °C < T < 98lg2P – 129lgP + 1300 °C, then following the CaC2- producing reaction CaO + 3C → CaC2 + CO, the reaction 2CaO + CaC2 → 3Ca +2CO will further occur to produce a calcium vapor. However, if a C/CaO molar ratio of the reaction system is ≥3, then the reaction CaO + 3C → CaC2 + CO will proceed completely, and there will be no CaO left to undergo the calcium-producing reaction 2CaO + CaC2 → 3Ca + 2CO with CaC2. As a result, the product of the system is CaC2, and there will be no calcium vapor released from the reaction system.”
Therefore, it is within the scope of applicant’s invention for the smelting reaction to produce a calcium vapor that always reacts with the carbon reducing agent to produce calcium carbide as recited in amended claim 1 lines 14-16.
Withdrawn Specification Objection
The following objection is withdrawn due to specification amendment:
Inconsistent presentation of a formula.
Response to Remarks filed January 26, 2026
Miura in view of one of Bretschneider, Mod, or Matsushima; Miura in view of one of Bretschneider, Mod, or Matsushima, and either one of Hansgrig or Kemmer
Applicant’s arguments, see Remarks p. 18 paras. 2-3, p. 19 para. 1, filed January 26, 2026, with respect to Miura have been fully considered and are persuasive. The rejections of Miura in view of one of Bretschneider, Mod, or Matsushima and of Miura in view of one of Bretschneider, Mod, or Matsushima, and either one of Hansgrig or Kemmer have been withdrawn.
The applicant persuasively argues amended claim 1 recites a reaction temperature T of “30lg2P + 58lgP + 1215°C < T < 98lg2P – 129lgP + 1300°C” (Remarks p. 18 para. 2) so that a calcium vapor will be produced and will always react with carbon reducing agent to produce calcium carbide, enabling highly efficient production of CaC2 (Remarks p. 18 para. 3), but in Miura a calcium vapor is not necessarily produced and even if it is produced then it will not always react with the carbon reducing agent to produce the calcium carbide, such that vapor is lost and the efficient product of CaC2 is impeded (Remarks p. 19 para. 1).
New Grounds
In light of claim amendment and upon further consider a new 112(a) rejection is made.
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 and 3-9 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.
Claim 1 lines 14-19 “wherein the smelting reaction produces a calcium vapor that always reacts with the carbon reducing agent to product the calcium carbide; where in the mixed powder, a molar content Mc of the carbon reducing agent, a molar content MMgO of the magnesium oxide and a molar content MCaO of the calcium oxide are in a relationship of: MC ≈ MMgO + 3MCaO” fails to comply with the written description requirement.
Claim 1 recites a molar ratio of CaO (MCaO) to C (MC) of 3:1.
However, with respect to the calcium vapor always reacting with carbon to produce calcium carbide, applicant’s specification recites:
Different CaO/C ratios will result in different ratios of the calcium to the calcium carbide…. Optionally, the mixed powder is prepared with the molar ratio CaO: C ≈ 1:3…, after the smelting reaction proceeds completely, the only products are calcium carbide and CO, and substantially no liquid calcium is produce (p. 7).
A molar ratio of C to CaO of at least 3 so that the system produces CaC2 without calcium vapor (p. 19).
When the molar ratio CaO:C is ≈ 1:3,…, only calcium carbide and CO will be produced, and there is substantially no calcium produced (p. 21).
Therefore, applicant’s specification discloses a CaO to C ratio of ≈ 1:3 in order to produce a calcium vapor that always reacts with the carbon reducing agent to produce the calcium carbide.
Claims 3-9 are rejected as depending from claim 1.
Related Art
Kirk (US 2,158,786)
Kirk discloses thermally reducing magnesium oxide materials to produce metallic magnesium by thermal reduction (1:1-7), including the reactions between MgO, CaO, and C (1:1:39-60, 1:2:1-15). In Kirk ground dolomite and graphite are mixed and reacted in an electrically heated furnace then magnesium is condensed and calcium carbide is produced (2:24-55).
Chubukov (Chubukov et al. Design and Fabrication of Pellets for Magnesium Production by Carbothermal Reduction. Metallurgical and Materials Transactions B. Volume 49B, October 2018. 2209-2218.)
Chubukov discloses carbothermal reduction (CTR) of pellets with MgO, CaO, and carbon (Abstract) treated at 10 kPa (10,000 Pa) and 1550°C for 3.5 hours with the product magnesium being condensed (II. Methods C. Experimental Procedure). Chubukov discloses a thermodynamic prediction for products of 2C + MgO-CaO at a pressure of 10 kPa that is dependent upon the reaction temperature (III. Results and Discussion A. Theoretical Predictions for the Carbothermal Reduction of Calcined Dolomite, Fig. 1) and how the ratio of C to MgO-CaO influences reduction (III. Results and Discussion B. Experimental Results for the Carbothermal Reduction of Calcined Dolomite).
Mauderli (Mauderli et al. Thermodynamics of the reduction of MgO by C and by CaC2. Helvetic Chimica Acta (1944) 27, 105-116.)
Mauderli discloses how temperatures of 289.1 to 2000°K and volt of 0 to about 3.25 influence the reactions between calcium (Ca), carbon (C), and oxygen (O) (Fig. 1) and how temperatures of 0 to 2000°K and Cp of 0 to about 20 influence CaC2, CaO, MgO, and graphite (Fig. 2, Table 1).
Wang (Wang et al. Thermodynamic Analysis of Mg Extraction from Calcined Dolomite by Carbothermic Reduction in Vacuum. Chinese Journal of Vacuum Science and Technology. 33. 11. (2013) 1144-1150.)
Wang discloses the temperature dependence of ΔGT for the following reactions at pressures of 1000 Pa and 100000 Pa: (1) CaO(s) + 3C(s) = CaC2)s) + CO(g); (2) CaO(s) + C(s) = Ca(g) + CO(g); (3) CaC2(s) + MgO(s) = Mg(s) + CaO(s) + 2C(s); (Figs. 1-3).
Chu (CN 107083491 machine translation)
Chu discloses simultaneously preparing metal magnesium and calcium carbide by a carbon thermal method ([0002]) to improve raw material utilization ([0028]) by mixing 60 to 70 parts magnesium oxide and calcium oxide mixed powder with 35 to 45 parts carbonaceous powder, and 2 to 5 parts of fluorite powder for a total weight of 100 parts ([0014]), pressing into pellets ([0015]-[0016]), and reacting at 10 Pa to 100 Pa and 1500°C to 1800°C ([0017]). Chu uses materials with finenesses of -100 mesh to -150 mesh ([0021]), and pellets with an equivalent diameter of 20 mm to 40 mm ([0022]).
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.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHANI HILL whose telephone number is (571)272-2523. The examiner can normally be reached Monday, Wednesday-Friday 7am-12pm.
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, KEITH WALKER can be reached on 571-272-3458. 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.
/STEPHANI HILL/Examiner, Art Unit 1735