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 .
This application is in response to election/restriction filed on 06/03/2026.
Claims 1-20 are pending. Applicant has elected Group I, claims 1-12, 17-20 without traverse and claims 13-16 are withdrawn as non-elected Group II.
Election/Restrictions
Applicant's election without traverse of Group I, claims 1-12 and 17-20 in the reply filed on 06/03/2026 is acknowledged.
Claims 13-16 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected Group II, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 06/03/2026.
Claim Objections
Claims 6 and 20 are objected to because of the following informalities:
It is suggested to amend “salt solid” to “salt is solid” to ensure proper antecedent basis and to provide clarity in the claim 6 line 2.
It is suggested to amend “at least once more” to “at least one or more times” to ensure to provide consistency in the claim 20 line 2.
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.
Claims 1-12 and 17-20 are rejected under 35 U.S.C. 103 as obvious over Zulkifli et al (US PGPUB No. 2022/0298022) in view of Um et al (US PGPUB NO.: 2018/0195146A1).
Regarding claims 1-5, 12 and 17, Zulkifli discloses a method for preparing rare earth carbonate, the method comprising: mixing rare earth sulfate with precipitating agent (reads conversion agent) comprising first sodium carbonate solution to form a first mixture and generating higher sulfate rare earth carbonate wet cake from the first mixture. The high sulfate rare earth carbonate wet cake can be mixed with a second sodium carbonate solution (reads on conversion agent) to form second sodium mixture generating lower sulfate rare earth carbonate less than 2 wt. sulfate (abstract, paragraphs 0010, 0017, 0027). Zulkifli further discloses agitating the mixture at 20-80°C for 1 to 10 hours at speed of 200 rpm to 440 rpm and the solid content is 10-70% (paragraphs 0040-0043, reads on claims 1-5, 12 and 17), filtering the mixture to generate filter cake , washing the filter cake with water (paragraphs 0044, 0070). As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, 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).
Zulkifli does not explicitly suggest or disclose utilization of mixing rare earth double sulfate salt.
However, Um discloses method utilizing sodium rare-earth double sulfate salt ((see abstract, paragraphs 0022-0023).
Therefore, it would have been obvious to one of the ordinary skill in the art at before the effective filing date of applicant invention to modify the method of Zulkifli with Um to include the double sulfate salts which would achieve great industrial benefits as taught by Um (abstract).
Regarding claim 6, Zulkifli discloses producing mixed rare earth carbonate with low sulfate content in a continuous manner from mixed rare earth sulfate solutions using sodium carbonate (paragraphs 0005, 0006, 0010, 0080).
Regarding claim 7, Zulkifli discloses rare earth content is about 40-72% and sodium carbonate concentration of 12-40 wt.% (paragraphs 0021-0024, 0027-0028, 0081-0082). As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, 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).
Regarding claim 8, Zulkifli does not explicitly disclose the ratio of weight ratio of rare earth sulfate salt to precipitating agent between 1.8:1 and 2:1 but however, Zulkifli discloses rare earth content is about 40-72% and sodium carbonate concentration of 12-40 wt.% (paragraphs 0021-0024, 0027-0028) therefore it would be obvious that the ratio of 1.8:1 and 2:1 would be expected unless otherwise unexpected results are shown by applicant. As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, 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).
Regarding claim 9, Zulkifli discloses wet cake having TREO about 45-72 wt.% and LOI from 28-55% and sulfate content of between 200 ppm to 2 wt.% (paragraphs 0023-0027). As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, 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).
Regarding claims 10-11, Zulkifli discloses washing the filter cake with water but does not explicitly disclose or suggest washing twice and the ratio of filter cake to water during washing is between 1kg filter cake to 8L water and 1kg filter cake to 12L water. However Zulkifli in view of Um discloses the method substantially identical to presently claimed invention and further disclosing washing the filter cake with water, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to optimize, by routine experimentation, washing twice or more and the ratio of filter cake to water of Zulkifli in view of Um, including amounts from 1kg filter cake to 8L and 1kg filter cake to 12L water as presently claimed, in order to achieve great industrial benefits as taught by Um (abstract). (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art (In re Aller, USPQ 223). See MPEP § 2144.05.
Regarding claim 18, Zulkifli discloses rare earth content is about 40-72% and sodium carbonate concentration of 12-40 wt.% (paragraphs 0021-0024, 0027-0028, 0081-0082). Zulkifli does not explicitly disclose the ratio of weight ratio of rare earth sulfate salt to precipitating agent between 1.8:1 and 2:1 but however, Zulkifli discloses rare earth content is about 40-72% and sodium carbonate concentration of 12-40 wt.% therefore it would be obvious that the ratio of 1.8:1 and 2:1 would be expected unless otherwise unexpected results are shown by applicant. As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, 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).
Regarding claim 19, Zulkifli discloses wet cake having TREO about 45-72 wt.% and LOI from 28-55% and sulfate content of between 200 ppm to 2 wt.%, temperature during agitating ranges from 10-80°C and agitation speed 200-440 rpm (paragraphs 0023-0027, 0040-0042). As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, 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).
Regarding claim 20, Zulkifli discloses washing the filter cake, agitating the mixture from 1 to 10 hours, temperature during the agitating is between 20 to 80°C (paragraphs 0040-0041, 0044,0054, 0059) but does not explicitly disclose repeat washing at least one or more time. But since Zulkifli discloses washing step, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to optimize, by routine experimentation, repeat washing at least one or more times in order to achieve great industrial benefits as taught by Um (abstract). (In re Boesch, 617 F.2d. 272, 205 USPQ 215 (CCPA 1980)), since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art (In re Aller, USPQ 223). See MPEP § 2144.05.
Conclusion
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/SMITA S PATEL/Primary Examiner, Art Unit 1732 10/01/2026
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