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 1-13, 15 and 17-20 are rejected under 35 U.S.C. 103 as being unpatentable over Rogers, Jr. (US Patent no. 4,133,727) in view of De Varda (US Patent no. 2,959,528).
Regarding claim 1, Rogers discloses a method for producing aluminum by the electrolytic reduction of aluminum chloride (col. 2, lines 4-6), comprising:
providing a cell (figure 1) comprising: a plurality of electrode stacks (two stacks are shown in figure 1) arranged in pairs (col. 3, lines 19-30), wherein each electrode stack comprises:
an upper terminal anode (46);
a lower terminal cathode (50); and
one or more intermediate bipolar electrodes (48) disposed between the upper terminal anode (46) and the lower terminal cathode (50) in a superimposed (col. 3, lines 19-30), vertically spaced relationship (as shown in figure 1) defining inter-electrode spaces (col. 3, lines 19-68);
a plurality of bath supply passages (56) extending downwardly along one side of each electrode stack (as shown in figure 1; col. 5, lines 23-47), and in fluid communication with:
(a) a bath reservoir (34) located above the plurality of upper terminal anodes (46; col. 3, lines 3-4);
(b) each inter-electrode space for that stack (col. 5, lines 23-47); and
(c) an aluminum product sump (26) located below the plurality of lower terminal cathodes (50; col. 5, lines 23-47); and
a plurality of bath return passages (55) extending upwardly between each of the paired electrode stacks (figure 1; col. 4, lines 9-24), and in fluid communication with:
(a) each inter-electrode space for both of the paired electrode stacks (col. 4, lines 9-24);
(b) the bath reservoir (34; col. 4, lines 9-24); and
(c) the aluminum product sump (26; as shown in figure 1);
adding aluminum chloride into the bath reservoir (34) using one or more feed ports (42; col. 3, lines 9-11);
removing a chlorine gas stream from the bath reservoir (34) using one or more off gas ports (44; col. 3, lines 11-13); and
removing molten aluminum from the aluminum product sump (26) using one or more tapping ports (38; col. 3, lines 4-18).
Rogers further teaches maintaining the desired circulation rate of a chloride bath within the cell (col. 3, lines 32-38; col. 4, lines 9-24). Even though Rogers fails to explicitly teach controlling the electrode current density, it has been held by the courts that where the general conditions are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. MPEP 2144.05.II.A. One of ordinary skill in the art at the time of filing would have found it obvious to conduct routine experimentation to adjust and determine the optimum electrode current density for producing aluminum in the electrolytic process of Rogers.
Rogers fails to teach one or more heater rods connected to the upper terminal anode, one or more heater rods connected to the lower terminal cathode; and preheating to at least 600oC using the one or more heater rods connected to the upper terminal anode and the one or more heater rods connected to the lower terminal cathode.
De Varda discloses a method and apparatus for starting an electrolytic furnace comprising a terminal anode, a terminal cathode and heater rods/resistors connected to the terminal electrodes in order to pre-heat the electrolytic furnace to a temperature in the range between 900-950oC (col. 1, lines 35-45; col. 2, lines 35-45; col. 3, lines 1-25; col. 4, lines 12-35).
One having ordinary skill in the art at the time of filing would have found it obvious to connect heater rods to the terminal electrodes of Rogers, as taught by De Varda, in order to pre-heat the electrolytic cell to a desired temperature.
Regarding claim 2, Rogers discloses wherein the cell further comprises one or more electrode bars (58) in electrical and thermal contact with each upper terminal anode (46), wherein the one or more electrode bars (58) functions as positive current leads and to provide independent thermal control to the upper terminal anode (col. 5, lines 48-56).
Regarding claim 3, Rogers further teaches wherein the one or more electrode bars (58) each comprise an outer conductive pipe and an inner conductive pipe with thermal conducting fins for providing thermal transfer between a cooling medium and the upper terminal anode (46; col. 5, lines 48-56 – the bars extend through cooling jacket walls where a cooling fluid flows through coolant inlet ports and is removed through an exit port; col. 2, lines 4-26).
Regarding claim 4, the cell of Rogers further comprises one or more electrode bars (62) in electrical and thermal contact with each low terminal cathode (50; as shown in figure 1), wherein the one or more electrode bars functions as negative current leads and to provide independent thermal control to the lower terminal cathode (col. 5, lines 48-56).
Regarding claim 5, the one or more electrode bars (62) of Rogers each comprise an outer conductive pipe and an inner conductive pipe with thermal conducting fins for providing thermal transfer between a cooling medium and the lower terminal cathode (50 - col. 5, lines 48-56 – the bars extend through cooling jacket walls where a cooling fluid flows through coolant inlet ports and is removed through an exit port; col. 2, lines 4-26).
Regarding claim 6, the cooling medium of Rogers is a cooling fluid (col. 2, lines 4-13).
Regarding claim 7, Rogers discloses controlling the flow of the cooling medium into the plurality of electrode bars (58; 62) to maintain the heat balance of the cell (col. 2, lines 4-26).
Regarding claim 8, Rogers further teaches maintaining the desired circulation rate of a chloride bath within the cell (col. 3, lines 32-38; col. 4, lines 9-24). Even though Rogers fails to explicitly teach controlling the electrode current density, it has been held by the courts that where the general conditions are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. MPEP 2144.05.II.A. One of ordinary skill in the art at the time of filing would have found it obvious to conduct routine experimentation to adjust and determine the optimum electrode current density for producing aluminum in the electrolytic process of Rogers.
Regarding claim 9, the chloride bath composition of Rogers comprises alkali/alkaline metal chlorides (col. 4, lines 1-8).
Regarding claim 10, the chloride bath composition of Rogers comprises alkali/alkaline metal chlorides (col. 4, lines 1-8).
Regarding claim 11, the chloride bath of Rogers comprises dissolved aluminum chloride (col. 2, lines 4-6).
Regarding claim 12, absent a showing of unexpected results, it would have been obvious to one of ordinary skill in the art to have conducted routine experimentation to determine suitable concentration ranges for producing aluminum in the electrolytic process of Rogers. MPEP 2144.05.II.A. It has been held by the courts that where the general conditions are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.
Regarding claim 13, absent a showing of unexpected results, it would have been obvious to one of ordinary skill in the art to have conducted routine experimentation to determine suitable concentration ranges for producing aluminum in the electrolytic process of Rogers. MPEP 2144.05.II.A.
Regarding claim 15, Rogers teaches adding a non-aluminum metal chloride to the bath reservoir in addition to aluminum chloride (col. 4, lines 1-8), wherein a molten alloy of the non-aluminum metal and aluminum is removed from the aluminum product sump (26) using the one or more tapping ports (38; col. 3, lines 4-18).
Regarding claim 17, Rogers further discloses wherein the removing molten aluminum step utilizes a vacuum to transfer a portion of the molten aluminum from the one or more tapping ports to an external metal transfer vessel for transport to a metal casting facility (col. 3, lines 3-18).
Regarding claims 18-20, the method of Rogers correlates to all the claimed method steps. Therefore, one having ordinary skill in the art would expect the method of Rogers to be capable of producing aluminum with a purity greater than 99.9%, as claimed.
Claims 14 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Rogers in view of De Varda as applied to claim 1 above, and further in view of Lippman et al. (US Patent no. 4,083,923).
Regarding claims 14, 16, the modified Rogers teaches all the features discussed above, but fails to disclose adding SiCl4 to the bath reservoir in addition to aluminum chloride, wherein a molten Si-Al alloy is removed from the aluminum product sump (26) using one or more tapping ports (38); and separating and recycling a portion of the chlorine gas stream back to the cell.
Lippman discloses a method for the electrolytic production of aluminum using a bath comprising aluminum chloride and silicon chloride, wherein chlorine gas generated during operation is recycled back into the cell in order to replace chlorine losses in the system during chlorination (col. 5, lines 27-46; col. 7, lines 50-65).
It would have been obvious to one having ordinary skill in the art at the time of filing would have found it obvious to add silicon chloride in addition to aluminum chloride in the electrolyte of the modified Rogers, as well as to recycle a portion of the chlorine gas stream back into the cell in order to replace chlorine losses in the system during chlorination, as taught by Lippman.
Claims 21-29 are rejected under 35 U.S.C. 103 as being unpatentable over Rogers, Jr. (US Patent no. 4,133,727) in view of Lippman et al. (US Patent no. 4,083,923).
Regarding claims 21 and 28, Rogers discloses a method for producing aluminum by the electrolytic reduction of aluminum chloride (col. 2, lines 4-6), comprising:
providing a cell (figure 1) comprising: a plurality of electrode stacks (two stacks are shown in figure 1) arranged in pairs (col. 3, lines 19-30), wherein each electrode stack comprises:
an upper terminal anode (46);
a lower terminal cathode (50); and
one or more intermediate bipolar electrodes (48) disposed between the upper terminal anode (46) and the lower terminal cathode (50) in a superimposed (col. 3, lines 19-30), vertically spaced relationship (as shown in figure 1) defining inter-electrode spaces (col. 3, lines 19-68);
a plurality of bath supply passages (56) extending downwardly along one side of each electrode stack (as shown in figure 1; col. 5, lines 23-47), and in fluid communication with:
(a) a bath reservoir (34) located above the plurality of upper terminal anodes (46; col. 3, lines 3-4);
(b) each inter-electrode space for that stack (col. 5, lines 23-47); and
(c) an aluminum product sump (26) located below the plurality of lower terminal cathodes (50; col. 5, lines 23-47); and
a plurality of bath return passages (55) extending upwardly between each of the paired electrode stacks (figure 1; col. 4, lines 9-24), and in fluid communication with:
(a) each inter-electrode space for both of the paired electrode stacks (col. 4, lines 9-24);
(b) the bath reservoir (34; col. 4, lines 9-24); and
(c) the aluminum product sump (26; as shown in figure 1);
adding aluminum chloride into the bath reservoir (34) using one or more feed ports (42; col. 3, lines 9-11);
removing a chlorine gas stream from the bath reservoir (34) using one or more off gas ports (44; col. 3, lines 11-13); and
removing molten aluminum from the aluminum product sump (26) using one or more tapping ports (38; col. 3, lines 4-18).
Rogers further teaches maintaining the desired circulation rate of a chloride bath within the cell (col. 3, lines 32-38; col. 4, lines 9-24). Even though Rogers fails to explicitly teach controlling the electrode current density, it has been held by the courts that where the general conditions are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. MPEP 2144.05.II.A. One of ordinary skill in the art at the time of filing would have found it obvious to conduct routine experimentation to adjust and determine the optimum electrode current density for producing aluminum in the electrolytic process of Rogers.
Rogers fails to teach adding SiCl4 to the bath reservoir in addition to aluminum chloride, wherein a molten Si-Al alloy is removed from the aluminum product sump (26) using one or more tapping ports (38), and separating and recycling a portion of the chlorine gas stream back into the cell.
Lippman discloses a method for the electrolytic production of aluminum using a bath comprising aluminum chloride and silicon chloride, wherein chlorine gas generated during operation is recycled back into the cell in order to replace chlorine losses in the system during chlorination (col. 5, lines 27-46; col. 7, lines 50-65).
It would have been obvious to one having ordinary skill in the art at the time of filing would have found it obvious to add silicon chloride in addition to aluminum chloride in the electrolyte of the modified Rogers, as well as to recycle a portion of the chlorine gas stream back into the cell in order to replace chlorine losses in the system during chlorination, as taught by Lippman.
Regarding claim 22, Rogers discloses wherein the cell further comprises one or more electrode bars (58) in electrical and thermal contact with each upper terminal anode (46), wherein the one or more electrode bars (58) functions as positive current leads and to provide independent thermal control to the upper terminal anode (col. 5, lines 48-56).
Regarding claim 23, Rogers further teaches wherein the one or more electrode bars (58) each comprise an outer conductive pipe and an inner conductive pipe with thermal conducting fins for providing thermal transfer between a cooling medium and the upper terminal anode (46; col. 5, lines 48-56 – the bars extend through cooling jacket walls where a cooling fluid flows through coolant inlet ports and is removed through an exit port; col. 2, lines 4-26).
Regarding claim 24, the cell of Rogers further comprises one or more electrode bars (62) in electrical and thermal contact with each low terminal cathode (50; as shown in figure 1), wherein the one or more electrode bars functions as negative current leads and to provide independent thermal control to the lower terminal cathode (col. 5, lines 48-56).
Regarding claim 25, the one or more electrode bars (62) of Rogers each comprise an outer conductive pipe and an inner conductive pipe with thermal conducting fins for providing thermal transfer between a cooling medium and the lower terminal cathode (50 - col. 5, lines 48-56 – the bars extend through cooling jacket walls where a cooling fluid flows through coolant inlet ports and is removed through an exit port; col. 2, lines 4-26).
Regarding claim 26, absent a showing of unexpected results, it would have been obvious to one of ordinary skill in the art to have conducted routine experimentation to determine suitable concentration ranges for producing aluminum in the electrolytic process of Rogers. MPEP 2144.05.II.A. It has been held by the courts that where the general conditions are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.
Regarding claim 27, absent a showing of unexpected results, it would have been obvious to one of ordinary skill in the art to have conducted routine experimentation to determine suitable concentration ranges for producing aluminum in the electrolytic process of Rogers. MPEP 2144.05.II.A.
Regarding claim 29, Rogers further discloses wherein the removing molten aluminum step utilizes a vacuum to transfer a portion of the molten aluminum from the one or more tapping ports to an external metal transfer vessel for transport to a metal casting facility (col. 3, lines 3-18).
Response to Arguments
Applicant’s arguments with respect to claims 1-20 have been considered but are moot because the new ground of rejection does not rely on the combination of references applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. The applicant argues that the prior art made of record fails to teach one or more heater rods connected to the upper terminal anode, one or more heater rods connected to the lower terminal cathode; and preheating to at least 600oC using the one or more heater rods connected to the upper terminal anode and the one or more heater rods connected to the lower terminal cathode, as amended. Therefore, after further search and consideration, new grounds of rejection have been presented in view of De Varda.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ZULMARIAM MENDEZ whose telephone number is (571)272-9805. The examiner can normally be reached M-F 8am-4:30p.
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/ZULMARIAM MENDEZ/Primary Examiner, Art Unit 1794