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 .
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.
Claim(s) 1-3 and 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kukurugya et al. (US 2021/0292869), hereinafter “Kukurugya.”
Regarding claim 1, Kukurugya teaches a method for refining a raw material iron oxide that is a by-product of a zinc melting process (Abstract, Figs. 1 and 3, [0021], [0034]-[0035], claim 6), the method comprising a roasting process of roasting raw material iron oxide thereby providing a roasted iron oxide cake (Figs. 1 and 3, [0021], [0023], [0034]), a washing process of washing a roasted iron oxide cake with water leaching, which uses a washing water (Figs. 1 and 3, [0011], [0030]), a first filtering process of filtering the washed iron oxide cake (Figs 1 and 3, [0032]), thereby providing refined iron oxide (Figs. 1 and 3, [0030]-[0035]).
Regarding claim 2, Kukurugya teaches wherein a roasting temperature is at least 650⁰C, preferably at least 675⁰C and 800⁰C or less ([0028]), which overlaps with the instantly claimed range. Kukurugya further discloses wherein the roasting may be carried out at 700⁰C specifically (Fig. 3). In the case where the claimed ranges “overlap or lie inside ranges disclosed by prior art” a prima facie case of obviousness exists. See MPEP §2144.05.
As to claim 3, Kukurugya teaches wherein the roasting process may further contain a drying process carried out at 40-105⁰C for a suitable time such as 12-48 hours ([0024]), which overlaps with the instantly claimed ranges. In the case where the claimed ranges “overlap or lie inside ranges disclosed by prior art” a prima facie case of obviousness exists. See MPEP §2144.05.
Regarding claim 5, Kukurugya teaches wherein a weight ratio of water to roasted mixture in the washing process is 5:1 and 15:1 (claim 15), which overlaps with the instantly claimed range of 140g to 160g roasted iron oxide cake per 1L of washing water, as 1L of water has a weight of 1000g. In the case where the claimed ranges “overlap or lie inside ranges disclosed by prior art” a prima facie case of obviousness exists. See MPEP §2144.05.
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kukurugya (US 2021/0292869) as applied to claim 1 above, and further in view of WO 20021/205903, wherein Hagio et al. (US 2023/0151453), hereinafter “Hagio,” is used and cited herein as an English language equivalent.
Regarding claim 4, Kukurugya teaches/renders obvious the method as recited in claim 1, as detailed above. Kukurugya further teaches wherein the roasting process is an oxidative roasting which may be carried out in an open reactor open to the outside atmosphere ([0028]) (i.e., under an air atmosphere), but does not explicitly specify using a rotary kiln. However, in the same field of endeavor, Hagio teaches that oxidative roasting may be carried out with a conventionally known rotary kiln ([0039]). Thus, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to carry out the roasting process of Kukurugya with rotary kiln, which is a conventionally known roasting furnace for oxidative roasting, as taught by Hagio.
Claim(s) 7, 9 and 11-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kukurugya (US 2021/0292869) as applied to claim 1 above, and further in view of Peters et al. (WO 88/03911), as cited in the IDS dated 3/5/2026, hereinafter “Peters.”
Regarding claims 7 and 9, Kukurugya teaches/renders obvious the method as recited in claim 1, as detailed above. Kukurugya is silent as to performing the washing process using an autoclave at a temperature of 130-150⁰C. However, Peters teaches that recovering metal from jarosite waste by leaching at a temperature greater than about 110⁰C yields a higher zinc leach extraction in an autoclave compared to a bomb reactor (claim 2, pg. 27 ln 16-20). Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention as filed to perform the water leaching process of Kukurugya using an autoclave at greater than about 110⁰C in order to improve leaching efficiency, as taught by Peters.
Regarding claims 11-13, Kukurugya discloses direct recovery of zinc by means of electrolysis ([0041]), but does not explicitly disclose using a selective zinc precipitation process. However, Peters teaches an alternative solution for zinc recovery, which is selective zinc precipitation with a salt such as sodium carbonate (p. 12 ln. 25-26, claim 19). Thus, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to carry out the zinc recovery process of Kukurugya using selective zinc precipitation with a salt, as taught by Peters, with a reasonable expectation of success. Regarding claim 13, Kukurugya modified by Peters teaches wherein the washing water as a pH 6-8 and a temperature of 15-75⁰C (Kukurugya: [0029]-[0030]), which overlaps with the instantly claimed ranges. In the case where the claimed ranges “overlap or lie inside ranges disclosed by prior art” a prima facie case of obviousness exists. See MPEP §2144.05.
Claim(s) 8 and 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kukurugya (US 2021/0292869) as applied to claim 1 above, and further in view of Kaplan et al. (US 2016/0045841), hereinafter “Kaplan.”
Regarding claims 8 and 10, Kukurugya teaches/renders obvious the method as recited in claim 1, as detailed above. Kukurugya teaches wherein the washing water has a temperature of 20-50⁰C, which overlaps with the range recited in claim 10, with a specific example using 25⁰C ([0030], Fig. 3). In the case where the claimed ranges “overlap or lie inside ranges disclosed by prior art” a prima facie case of obviousness exists. See MPEP §2144.05. Kukurugya is silent as to the washing process being carried out with an agitator. However, in the same field of endeavor of non-ferrous hydrometallurgy, Kaplan teaches that using an agitator promotes the best leaching action ([1290]). Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to perform the water leaching process of Kukurugya using an agitator in order to promote the best leaching action, as taught by Kaplan.
Allowable Subject Matter
Claim 6 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
Regarding claim 6, the prior art fails to disclose or fairly suggest the method as recited. In particular the closet prior art, Kukurugya (US 2021/0292869) teaches a method for refining a raw material iron oxide that is a by-product of a zinc melting process (Abstract, Figs. 1 and 3, [0021], [0034]-[0035], claim 6), the method comprising a roasting process of roasting raw material iron oxide thereby providing a roasted iron oxide cake (Figs. 1 and 3, [0021], [0023], [0034]), a washing process of washing a roasted iron oxide cake with water leaching, which uses a washing water (Figs. 1 and 3, [0011], [0030]), a first filtering process of filtering the washed iron oxide cake (Figs 1 and 3, [0032]), thereby providing refined iron oxide (Figs. 1 and 3, [0030]-[0035]). However, Kukurugya does not teach or fairly suggest wherein the refined iron oxide contains 60 wt% or more of iron, 0.3 wt% or less of zinc, 0.1 wt% or less of potassium, 0.1 wt% or less of sodium, and 0.5 wt% or less of sulfur, as required by claim 6. Thus, claim 6 is distinct over the teachings of the prior art.
Conclusion
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/ANTHONY M LIANG/Primary Examiner, Art Unit 1734
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