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.
Claims 1-7 are rejected under 35 U.S.C. 103 as being unpatentable over Farquharson et al (US 5,385,586) in view of La et al (US 2010/0254866).
Regarding claim 1, Farquharson et al disclose a Bayer plant for dissolving alumina contained in bauxite and configured to add Bayer liquor to bauxite on the red side of the plant. (See the paragraph bridging columns 3 and 4, particularly the sentence bridging columns 3 and 4 which discloses that the treated liquor is recycled to a digestion step. The differences between the plant disclosed by Farquharson et al, and that recited in applicant’s claims, are that Farquharson et al do not disclose unit operations on the red side of the plant configured to control a bauxite reactive silica concentration in the Bayer liquor to facilitate removal of oxalates from solution in the Bayer liquor, and wherein there is no unit operations for oxalate removal on the white side of the plant. LA et al disclose a method of controlling silica in the liquor circuit of the Bayer process which involves addition of a promotor material to enhance the precipitation of DSP (desilication product) and includes adding one or more silica dispersion materials or dry silica forms to those parts of the circuit where precipitation of DSP and removal of silica is desirable. (See the Abstract and Paragraph [0013].) It would be obvious from La et al to modify the plant of Farquharson et al by including unit operations for the red side which are configured to control a bauxite reactive silica concentration in the Bayer liquor to facilitate removal of oxalates from solution in the Bayer liquor. One of ordinary skill in the art would be motivated to do so, since La et al establish in Paragraph [0008] the conventionality of incorporating a desilication step in the Bayer process. It would be further obvious to provide no unit operations for oxalate removal on the white side of the plant disclosed by Farquharson et al, since Farquharson et al teach at col. 3, lines15-20 that stabilization of sodium oxalate in the Bayer liquor will allow the decrease in precipitation temperature without co-precipitation of sodium oxalate, with a further disclose at col. 3, lines 25-27 that the invention stabilizes dissolved sodium oxalate leading to improved classification of alumina trihydrate.
Regarding claim 2, the desilication stage of la et al would operate in accordance with a relationship that he concentration of oxalate in solution in Bayer liquor decreases as the bauxite reactive silica concentration increase to no less extent than in the plant recited in claim 2, since such relationship ship is an inherent property. In any event, the recitation of “operates” is a method limitation which is not given weight in an apparatus claim.
Regarding claim 3, the unit operation for recycling of the treated liquor to the digestion step disclosed in the sentence bridging columns 3 and 4 of Farquharson et al would be capable of driving removal of oxalate as a desilication product, since the structure of such unit operation would not be distinguishable form the structure of the unit operation recited in claim 3.
Regarding claim 4, Farquharson et al teach at col. 3, lines 10-27 that the sodium oxalate is not precipitated. The unit operation used to control such concentration of sodium oxalate in the plant of Farquharson et al would be configured to control the concentration of oxalates in solution in the Bayer liquor on the whit side to be supersaturated, since this would depend on the manner of operating the process, rather than the structure of the unit operation used to control the concentration of the oxalates.
Regarding claim 5, Farquharson et al disclose at col. 3, lines 23-27 that co-precipitation of sodium oxalate can lead to inefficiencies in the classification of alumina hydrate. It would be expected from such disclosures that oxalates would also be absorbed onto bauxite residues. In any event, the unit operation disclosed in Farquharson et al to remove oxalates would be configured to absorb oxalates onto bauxite residues on the red side of the plant to no less extent than the unit operation recited in claim5.
Regarding claim 6, the unit operation used to control the contents of the desilication stage of La et al would be configured to control the bauxite reactive silica concentration in the Bayer liquor to be below a maximum concentration, since such concentration would be dependent on the manner of operating the unit operation, which is a method limitation.
Regarding claims 7 and 8, the plant of Farquharson et al appears to include a unit operation configured to increase oxalate concentration in the Bayer liquor by stopping altogether oxalate removal in the white side, since Farquharson et al discloses at col. 3, lines 10-27 that there is no co-precipitation of sodium oxalate.
Regarding claim 9, the recycled liquor to the digestion step in the sentence bridging columns 3 and 4 of Farquharson et al would contain oxalates, since Farquharson et al suggest at col. 3, lines 10-27 that there is no co-precipitation of sodium oxalate.
Regarding claim 10, La et al disclose in Paragraph [0013] that silica is added in the desilication stage.
Regarding claims 11 -13, La et al disclose a heat exchanger in Figure 1 which would be capable of heating a slurry in the plant. La et al further disclose precipitation stage in Figure 1 which separates solids from liquid, presumably after a cooling step.
Regarding claim 14, Farquharson et al suggest at col. 2, lines 24-36 that here are sodium oxalate impurities in the recovered alumina trihydrate. It would be obvious from disclosure to include a unit operation configured to wash separated solids and to remove the sodium oxalate impurities.
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.
Claim 2 is 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. The recitation of “operates in accordance with a relationship…” renders the scope of the claim vague and indefinite, since this is a method limitation in an apparatus claim. Method limitations in apparatus claims are improper, since it is the apparatus structure which is covered in an apparatus claim, and not the method of using such structure. In any event, the limitation is indefinite since there is no nexus between the actual bauxite reactive silica concentration and the concentration of oxalate.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to WAYNE A LANGEL whose telephone number is (571) 272-1353. The examiner can normally be reached Monday through Friday from 8:15 am to 4:15 pm.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Anthony Zimmer can be reached at 571-270-3591. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/WAYNE A LANGEL/ Primary Examiner, Art Unit 1736
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