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 .
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 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.
Claims 1-8 are rejected under 35 U.S.C. 103 as being unpatentable over CAGNOLATTI ET AL (newly cited) in view of EP0203873 (A1), further in view of DE2918520 (C2). CAGNOLATTI ET AL disclose a method for processing bauxite to produce alumina, comprising filtering an alumina slurry obtained after a digestion of the bauxite, wherein the alumina slurry is filtered, ater wash, and a solid phase of red mud. (See FIG 1 and its description.). CAGNOLATTI ET AL further teach at col. 4, lines 29-42 that that the mud cake which is deposited in the filter press is washed, and in col. 4, lines 26-28 that the dilute liquor passing through the mud is injected into the main clarified Bayer liquor stream. (See “ALTERNATE” in Embodiment A in FIG. 1, which makes it clear that mud filtering and mud washing occurs on the same device. The differences between the process disclosed by CAGNOLATTI ET AL, and that recited in applicant’s claims, are that CAGNOLATTI ET AL do not disclose the filtering is carried out at a temperature of at least 95 C, and that the washing is carried out at a temperature of below 98 C.) EP0203873 (A1) discloses the Bayer process by attacking bauxite at a temperature between 100 and 170 C, and the separating the liquor from the insoluble residues from the attack. (See claim 1 of the English translation.) DE 2918520 (C2) discloses the Bayer process and teaches in Paragraph [0022] of the English translation that the red mud is washed with hot water at a temperature of 40 C or more. It would have been obvious from EP 0203873 (A1) to filter the slurry in the process of CAGNOLATTI ET AL at a temperature of at least 95 C. One of ordinary skill in the art would have been motivated to do so, since EP0203873 (A1) teaches in claim 1 that the bauxite attack occurs between 100 and 170 C and then separated from the insoluble residues, with no indication that cooling occurs between those steps. It would have been further obvious from DE2918520 (C2) to wash the red mud of CAGNOLATTI ET AL with water at a temperature of below 98 C. One of ordinary skill in the art would have been motivated to do so, since DE2918520 (C2) discloses a hot water wash in Paragraph [0022] of the English translation, and the processes of CAGNOLATTI ET AL and DE2918520 (C2) are analogous in that both are directed to the Bayer process including the steps of filtration and washing of the red mud.
Regarding claim 6, it would have been within the level of skill of one of ordinary skill in the art to determine a suitable rate of consumption of the hot water in the washing step.
Regarding claim 7, centrifuges and filter presses are conventionally used in filtration processes.
Regarding claim 8, EP0203873 (A1) discloses in Paragraph [0055] that the filtrate is recycled directly to the precipitation.
Response to Arguments
Applicant’s argument, that the claimed method recites filtering the slurry and washing the solid phase of red mud on the filtration equipment, which replaces conventional mud circuit and security filtration area of the green liquor, is not convincing, since the filtration equipment and washing step in the process of CAGNOLATTI ET AL would replace a conventional mud circuit and security filtration of the green liquor to no less extent than in the process recited in applicant’s claims. Applicant’s argument, that the claimed method can be used to process any kind of bauxite, reduces the number of stages (operations), and reduces the duration of the interaction between the solid and liquid phases as compared with the conventional methods, which decrease the losses of alumina, alkali, flocculant and lime, and reduces the amount of wash water added to the process by two times, is not convincing, since these attributes would also be present in the process of CAGNOLATTI ET AL In that CAGNOLATTI ET AL discloses that the washing step occurs on the filtration equipment. Applicant’s argument, that EP0203873 (A1) is silent on a filtering temperature, and that the temperature range of bauxite digestion of 100 to 170 C has nothing to do with the filtering temperature of the slurry, is not convincing. EP0203873A1 discloses in claim 1 of the English translation that the bauxite is attacked at a temperature between 100 and 170 C, then separated from the insoluble residues from the attack, “then cooled” to precipitate part of the alumina. The fact that EP0203873A1 discloses that the liquor is “then cooled” after separation from the insoluble residues would imply that the liquor was not cooled between the attack and separation steps. Applicant’s argument, that the process of DE2918520 (C2) is directed to the process related to washing aluminum hydrate seed with water to remove organic impurities, and does not teach or suggest the claimed step of washing at a temperature of below 98 C, is not convincing, DE2918520 (C2) teaches in Paragraph [0022] of the English translation that the water can be any type that does not contaminate the aluminum hydroxide product and does not contain any substances that cause difficulties during the recirculation process in the Bayer process, is not convincing, since one of ordinary skill in the art would have appreciated from such disclosure that that the type and temperature of wash water used in the process of DE2918520 (C2) would also be suitable for use in the process of CAGNOLATTI ET AL, since the processes of CAGNOLATTI ET AL and DE2918520 (C2) and are both directed to the Bayer process including a step of recirculating the water. Applicant’s argument, that to arrive at the claimed method it was necessary to carry out extensive work to select materials for the filter plates and to develop the structures capable of withstanding temperatures of up to 120 C and pressures of up to 8 atm at caustic alkali concentrations of 160 g/L in terms of Na2O caustic, is not convincing, since applicant’s claims do not specifying material for the filter plates or require any pressure above atmospheric, and do not require any temperature greater than 95 C. Applicant’s argument, that the claimed method allows for entirely removing the flocculent and for increased liquor productivity of 5-15 kg/m3 as compared with the conventional method, is not convincing, since there is no evidence on record showing that the process of CAGNOLATTI ET AL would not also allow for entirely removing the flocculant and for increased liquor productivity of 5-15 kg/m3.
Regarding claim 6, that the claimed method allows for achieving a specific consumption of water of 2.0 m3/t of red mud and simultaneously reduces alkali losses with disposed mud by 70% by filtering the alumina process slurry and washing the solid phase of the red mud on the same filtration equipment, is not convincing, since CAGNOLATTI ET AL disclose the filtration and washing steps on the same filtration equipment in FIG. 1 and its description.
WO 00/64812 is made of record for is reference to CAGNOLATTI ET AL (US 3,210,155).
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.
Conclusion
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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