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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 03/25/2026 has been entered.
Status of Rejections
All previous rejections are maintained and modified only in response to the amendments to the claims.
Claims 1-2, 4, 7-8, 11-14, 16-22, 24 and 30-33 are pending and under consideration for this Office Action.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-2, 4, 7-8, 11-14 and 30 are rejected under 35 U.S.C. 103 as being unpatentable over D’Astolfo et al. (U.S. 2005/0199508), in view of D’Astolfo et al. (U.S. 2003/0141196, hereinafter D’Astolfo2), and further in view of Adler (U.S. Patent No. 4,057,480), Clark et al. (U.S. Patent No. 4,491,510), and Crottaz et al. (WO 2004/035870).
Regarding claim 1, D’Astolfo teaches an anode assembly (see e.g. Fig. 1, anode assembly 10; Paragraph 0017, lines 1-2), comprising:
an anode apparatus (see e.g. Paragraph 0017, lines 3-5) configured to direct current into a molten electrolyte bath (see e.g. Paragraph 0008, lines 2-5), wherein the anode apparatus comprises:
(a) an anode body comprising at least one outer sidewall, wherein the at least one outer sidewall is configured to define a shape of the anode body (see e.g. Fig. 1, outer wall defining cup-shaped inert anode 12; Paragraph 0017, lines 3-5), and to perimetrically surround a hole in the anode body (see e.g. Fig. 1, hole defined by interior walls of anode 12), wherein the hole comprises an upper opening in a top surface of the anode body and wherein the hole axially extends into the anode body (see e.g. Fig. 1, opening at upper part of anode 12 which extends downward forming the hole);
(b) a pin (see e.g. Fig. 1, conductor rod 14; Paragraph 0017, lines 4-5) comprising:
a. a first end connected to a current supply (see e.g. Fig. 1, exposed upper end of conductor rod 14 connects to power supply; Paragraph 0043, lines 8-10), and
b. a second end opposite the first end, wherein the second end extends downward into the upper opening of the anode body and into the hole of the anode body (see e.g. Fig. 1, lower end of conductor rod 14 extends into the anode body 12);
(c) a filler material inside the hole and configured to electrically connect the anode body to the pin (see e.g. Fig. 1, particulate connector material 16; Paragraph 0017, lines 5-7, and Paragraph 0029, lines 1-3), wherein the filler material is retained in the hole between an inner sidewall of the anode body and the pin (see e.g. Fig. 1, connector material 16 fills the gap G between the inner anode surface and the conductor rod; Paragraph 0017, lines 5-7); and
(d) a sealing material configured to reduce corrosion of the anode apparatus (see e.g. Fig. 1, seal 18 which seals off the inner portion of the anode body, and thereby prevents or reduces exposure of contained anode parts to potential corrosion; Paragraph 0017, lines 7-9), the sealing material comprising an aggregate and a matrix (see e.g. Paragraph 0027, the sealing material may be a castable ceramic or cermet, meeting the definition of an aggregate and a matrix as per paragraph 0084 of the instant specification), the aggregate being an anode-matched aggregate (see e.g. Paragraphs 0027, lines 2-6, and Paragraph 0036, lines 1-4, both the seal and the inert anode comprise ceramic or cermet materials, with aluminum oxide particularly present in both), wherein the sealing material covers at least a portion of:
the inner sidewall of the anode body, the pin and the filler material (see e.g. Fig. 1, seal 18 covers the upper inner wall of anode 12, a portion of conductor 14 at the top of the anode, and the top of the connector material 16);
wherein the sealing material is configured to enclose the filler material into the anode body between the inner sidewall of the anode body and the pin (see e.g. Fig. 1, seal 18 seals connector material 16 into the anode body 12; Paragraph 0017, lines 7-9), such that the sealing material provides mechanical attachment of the anode body to the pin (see e.g. Paragraph 0027, lines 8-10, seal provides mechanical support by transferring weight of the anode to the conductor rod, i.e. via mechanical attachment therebetween);
wherein the sealing material comprises a castable ceramic or cermet comprising Al2O4, SiO2, MgO, CaO and/or NaO (see e.g. Paragraph 0027, lines 2-4); and
wherein said anode matched aggregate comprising aggregates having a composition 70% of a major compound of the anode body (see e.g. Paragraph 0027, lines 4-6, and Paragraph 0036, lines 3-8, Al2O3 being a major compound of the anode body and the seal material comprising Beta 70 castable sold by Permatech which has 70% Al2O3, as evidenced by D’Astolfo2 Paragraph 0035).
D’Astolfo does not explicitly teach an anode support to which the anode apparatus is mechanically attached.
D’Astolfo2 teaches an anode system for an aluminum electrolysis apparatus (see e.g. Paragraph 0019, lines 1-3) comprising a support system to which inert anodes are mechanically attached (see e.g. Fig. 1, support system including refractory support 12 and top metal plate 18 supporting inert anodes 14 and 14” via metal bolts 16; Paragraph 0019, lines 4-11), enabling mounting of the anodes and providing a continuous electrical path from the cell (see e.g. Paragraph 0004, lines 1-5).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the anode assembly of D’Astolfo to comprise a support system to which the anode apparatus is mechanically attached as taught by D’Astolfo2 to enable mounting of the one or more anode apparatuses in an aluminum electrolysis apparatus comprising the anode assembly and provide a continuous electrical path from the electrolysis cell. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Modified D’Astolfo does not teach the sealing material being bonded to and covering the top surface of the anode body and extending beyond a peripheral edge of the top surface and covering a portion of the at least one outer sidewall of the anode body configured to be positioned in a vapor space above the molten electrolyte bath, such that the sealing material extends down the at least one outer sidewall and terminates at a portion of the at least one outer sidewall configured to be proximate to a bath-vapor interface, the sealing material further covering at least a portion of the anode support, and the sealing material being retained above the top surface of the anode body.
Alder teaches a ceramic anode for molten electrolysis (see e.g. Abstract), which is provided with a protective layer that is bonded to the top surface and may extend partially down the sidewalls of the anode body to a three phase zone interface between the electrolyte and surrounding atmosphere (see e.g. Figs. 1-2 and 4, protective layer 2 bonded to upper surfaces and at least part of sidewalls of anode 3 in three phase zone; Col. 3, lines 8-13, Col. 4, lines 35-40, and Col. 6, lines 25-30, 36-39 and 62-63), may extend into a horizontal support for the anode (see e.g. Fig. 9, protective layer 2 extending along power lead 1 into horizontal top 14 of cell through which anode assemblies extend), and serves to protect these surfaces from corrosion (see e.g. Col. 5, lines 23-32), the protective layer comprising a material which is resistant to attack by the molten electrolyte (see e.g. Col. 6, lines 20-22), such as Al2O3 (see e.g. Col. 6, lines 25-28), which is also a main component of the sealing material taught by D’Astolfo (see e.g. D’Astolfo Paragraph 0027, lines 1-4).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the sealing material taught by D’Astolfo in view of Martin to be bonded to and cover the top surface and extend partially down the sidewalls of the anode body to a three phase zone interface between the electrolyte and surrounding atmosphere and additionally cover a portion of the anode support as taught by Alder to provide these surfaces with protection from corrosion by the molten electrolyte.
Modified D’Astolfo does not explicitly teach the sealing material having a coefficient of thermal expansion that substantially overlaps with a coefficient of thermal expansion of the anode body. D’Astolfo does however teach both the anode body and the sealing material comprising conductive ceramic or cermet materials (see e.g. D’Astolfo Paragraph 0027, lines 1-2, and Paragraph 0036, lines 1-6).
Clark teaches an anode for aluminum electrolysis (see e.g. Abstract) comprising a conductive core composed of a first conductive ceramic material covered by an adherent coating of a second conductive ceramic material having a closely matching coefficient of thermal expansion to the first conductive ceramic material (see e.g. Fig. 1, core 11 with adherent coating 12; Col. 3, lines 51-65), the coating protecting the anode core by providing corrosion resistance above and below the melt as well as at the melt/ambient interface (see e.g. Col. 3, lines 17-21, and Col. 6, lines 19-21), and the closely matching coefficients of thermal expansion preventing destruction of the anode during use (see e.g. Col. 4, lines 22-28).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the corrosion protecting sealing material of modified D’Astolfo to have a coefficient of thermal expansion closely matching that of the anode body as taught by Clark to protect the surfaces of the anode body by providing corrosion resistance while preventing destruction of the anode during use.
Modified D’Astolfo does not teach at least some of the silicates and/or aluminates of said castable ceramic or cermet being replaced with an aggregate specifically tailored to match the anode body and/or the pin, wherein the aggregate is specifically tailored to not undergo chemical reactions with the anode body and/or pin. D’Astolfo does however teach the anode comprising ceramic materials such as nickel, aluminum and/or zinc oxides (see e.g. D’Astolfo Paragraph 0036, lines 1-6), as well as the sealing material comprising predominantly aluminum oxide (see e.g. D’Astolfo Paragraph 0027, lines 1-4, the seal material comprising Beta 70 castable sold by Permatech which has 70% Al2O3, as evidenced by D’Astolfo2 Paragraph 0035).
Crottaz teaches a coating for protecting an anode conductor in an aluminum electrowinning cell from cell gases (see e.g. Abstract), the coating being a ceramic coating made predominantly of aluminum oxide and containing at least one other ceramic compound such as oxides of nickel and zinc (see e.g. Page 4, lines 18-24, and Page 5, lines 5-7), these compounds being resistant to fluorides and not significantly reducing the protective capacity of alumina against cell gases (see e.g. Page 4, lines 25-29), and thereby having stability against reactions with other anode structure components (see e.g. Page 5, lines 17-19, and Page 9, lines 19-23, coating resistant to oxidation and corrosion by reactive gases, the high alumina content providing high chemical stability; this resistance to reactive gases that would cause the sealing material to corrode the pin or reduce the structural integrity of the anode body being what is similarly exemplified in paragraphs 0143-0145 of the instant specification as “not undergo[ing] significant reactions”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the ceramic sealing material of modified D’Astolfo to comprise, in addition to the major aluminum oxide component, another ceramic compound such as nickel or zinc oxide, which may also be present in the anode, as taught by Crottaz to provide resistance to fluoride gases in the cell without significantly reducing the protective capacity of the aluminum oxide against cell gases.
Regarding claim 2, modified D’Astolfo does not explicitly the sealing material comprising at least one of water, a dispersant, or a diluent, to promote a flowable sealing material such that the flowable sealing material flows and covers the surface of the anode body and said at least a portion of the inner sidewall of the anode body; the pin; the filler material; and the anode support. D’Astolfo does however teach the sealing material being a castable that is cast in place and cured (see e.g. D’Astolfo Paragraph 0027, lines 1-8).
D’Astolfo2 further teaches that castable materials are typically supplied as dry mixed materials and combined with water or other specified liquid at the site of application in order to be poured into a mold of specific features and dimensions (see e.g. Paragraph 0024, lines 21-26).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the sealing material taught by modified D’Astolfo to include water as taught by D’Astolfo2 as a typical liquid added to a castable to allow it to be poured for application. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Regarding claim 4, D’Astolfo as modified by D’Astolfo2 teaches the first end of the pin being configured to be retained within the anode support (see e.g. D’Astolfo2 Fig. 1, tops of bolts 16 shown retained within refractory support 12 and top metal plate 18)
Regarding claim 7, the limitation of the sealing material being cast in place is a product-by-process limitation. There is no indication in the disclosure of a structural difference resulting from how the sealing material is cast. MPEP § 2113 states “"[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.". Modified D’Astolfo teaches all the structural limitations of the claimed assembly as stated above. Regardless, modified D’Astolfo further teaches the sealing material being cast in place (see e.g. D’Astolfo Paragraph 0027, line 6).
Regarding claim 8, the limitation of the sealing material being pre-cast and screwed into the anode body is a product-by process limitation. There is no indication in the disclosure of a structural difference resulting from how the sealing material is cast. MPEP § 2113 states “"[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.". Modified D’Astolfo teaches all the structural limitations of the claimed assembly as stated above. Regardless, modified D’Astolfo further teaches the sealing material being pre-cast and screwed into the anode body (see e.g. D’Astolfo Paragraph 0027, lines 6-7).
Regarding claim 11, modified D’Astolfo teaches the sealing material being retained in the hole (see e.g. D’Astolfo Fig. 1, seal 18 in the hole formed by inert anode 12; Paragraph 0017, lines 7-9).
Regarding claim 12, D’Astolfo as modified by Adler teaches above the top surface of the anode body including extending along the pin (see e.g. Adler Fig. 4, protective layer 2 surrounding power lead 1; Col. 6, lines 62-63).
Regarding claim 13, D’Astolfo as modified by D’Astolfo2 and Adler teaches above the top surface of the anode body including extending along the pin and into the anode support (see e.g. D’Astolfo2 Fig. 1, tops of bolts 16 shown retained within refractory support 12 and top metal plate 18; see e.g. Adler Fig. 9, protective layer 2 extending along power lead 1 into horizontal top 14 of cell through which anode assemblies extend).
Regarding claim 14, D’Astolfo as modified by Adler teaches above the top surface of the anode body including extending across the top surface of the anode body (see e.g. Adler Fig. 4, protecting layer 2 across top surface of anode 3; Col. 6, lines 62-63).
Regarding claim 30, D’Astolfo as modified by Adler further teaches an electrolysis cell comprising the anode assembly (see e.g. D’Astolfo Paragraph 0001 and Paragraph 0041, lines 13-15, electrolytic metal production cell, such as aluminum production cell, comprising anode assembly), and a cell structure comprising a control volume containing the molten electrolyte bath with the vapor space located above the molten electrolyte bath, and wherein the sealing material terminates at and proximate to the bath-vapor interface (see e.g. D’Astolfo Paragraph 0008, lines 2-5, and Paragraph 0041, lines 14-15, electrolytic molten salt bath; see e.g. Adler Col. 4, lines 35-40, and Col. 6, lines 36-39, anode sidewalls may be partially covered with protective material only to the extent that three phase zone interface between the electrolyte and surrounding atmosphere is protected, i.e. extending terminating at said interface).
D’Astolfo as modified above does not explicitly teach the cell structure comprising a cell bottom and a cell sidewall, wherein the cell sidewall is configured to perimetrically surround the cell bottom and extend in an upward direction to define the control volume.
Adler further teaches a cell for molten aluminum electrolysis (see e.g. Abstract) comprising a cell structure comprising a cell bottom and a cell sidewall, wherein the cell sidewall is configured to perimetrically surround the cell bottom and extend in an upward direction to define a control volume, wherein the control volume is configured to retain a molten electrolyte bath (see e.g. Figs. 7-9, cell trough 12 with upwardly extending sidewalls perimetrically surrounding a floor, defining a volume containing molten electrolyte 4; Col. 7, lines 20-25, and Col. 6, lines 22-24).
It would have been obvious to one of the ordinary skill in the art before the effective filing date of the claimed invention to have modified the cell of D’Astolfo to comprise a structure including a cell bottom and an upwardly extending cell sidewall perimetrically surrounding the cell bottom as taught by Adler as a suitable structure for retaining the molten electrolyte bath of an aluminum electrolysis cell. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Claims 16-18 are rejected under 35 U.S.C. 103 as being unpatentable over D’Astolfo, D’Astolfo2, Adler, Clark and Crottaz, as applied to claim 1 above, and further in view of Liu (WO 2017223348 A1).
Regarding claim 16, modified D’Astolfo teaches all the elements of the anode apparatus of claim 1 as stated above. Modified D’Astolfo does not teach the sealing material being applied to the hole in the anode body between the pin and the inner sidewall of the anode body in a gradient, such that a concentration of said aggregate of the sealing material varies in a radial direction. D’Astolfo does however teach the sealing material comprising cermet materials (see e.g. D’Astolfo Paragraph 0027, lines 1-2).
Liu teaches an anode for an aluminum electrolysis cell (see e.g. Paragraph 00044, lines 2-4) comprising an outer ceramic shell and an inner metallic core (see e.g. Figs. 1A-1B, outer shell 300 and core 100; Paragraph 0044, lines 4-6, and Paragraphs 0045 and 0050) with an intermediate cermet layer provided between them (see e.g. Figs. 1A-1B, intermediate layer 200 or sub-layers 210/220/230; Paragraph 0044, lines 5-6, Paragraph 0056, lines 1-3and Paragraph 0058, lines 1-6), the intermediate layer comprising a gradient of the relative concentrations of the ceramic and metal materials composing the cermet between the ceramic shell and metal core to compensate for the difference in thermal expansion between the outer shell and core and thereby prevent the outer shell from cracking (see e.g. Paragraph 0056, lines 15-18, and Paragraphs 0053-0054 and 0057).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the sealing material of modified D’Astolfo to form a concentration gradient of ceramic and metal components radially between the outer anode body and the inner pin as taught by Liu to compensate for the difference in thermal expansion between the anode body and pin and thereby prevent the anode body from cracking.
Regarding claim 17, D’Astolfo as modified by Liu teaches the gradient being configured such that the concentration of said aggregate is higher adjacent to the pin as compared to adjacent to the inner surface of the anode body (see e.g. Liu Paragraph 0056, lines 2-4 and 15-18, ceramic concentration of cermet increases from inner boundary, i.e. adjacent pin, to outer boundary, i.e. adjacent inner anode body surface, resulting in the balance metal aggregate concentration being higher adjacent to the pin).
Regarding claim 18, D’Astolfo as modified by Liu teaches the gradient being configured such that the concentration of said aggregate is lower adjacent to the pin as compared to the inner surface of the anode body (see e.g. Liu Paragraph 0056, lines 2-4 and 15-18, ceramic concentration of cermet increases from inner boundary, i.e. adjacent pin, to outer boundary, i.e. adjacent inner anode body surface, therefore being lower adjacent to the pin).
Claims 19-22 are rejected under 35 U.S.C. 103 as being unpatentable over D’Astolfo, D’Astolfo2, Adler, Clark and Crottaz, as applied to claim 1 above, and further in view of Li et al. (CN 1548586 A, citations based on translation).
Regarding claim 19, modified D’Astolfo teaches all the elements of the anode apparatus of claim 1 as stated above. Modified D’Astolfo does not teach the sealing material being applied to the hole in the anode body between the pin and the inner sidewall of the anode body in a gradient, such that the concentration of said aggregate varies in a lateral direction. D’Astolfo does however teach the sealing material comprising cermet materials (see e.g. D’Astolfo Paragraph 0027, lines 1-2) and being provided at the open upper end of the anode body on top of a metal filler material (see e.g. D’Astolfo Paragraph 0017, lines 7-9).
Li teaches a metal ceramic inert anode for aluminum electrolysis (see e.g. Paragraph 0002) wherein the metal ceramic material may be provided in a gradient in the radial or axial, i.e. lateral, directions, by increasing and decreasing the relative metal and ceramic phase contents (see e.g. Paragraph 0006, Paragraph 0011, lines 1-3, and Paragraph 0013, lines 1-6), an increased ceramic phase content in an outer layer providing higher resistance from electrolyte corrosion (see e.g. Paragraph 0016, lines 2-4) and an increased metal phase content adjacent a metal component providing good thermal shock resistance (see e.g. Paragraph 0016, lines 4-5).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the sealing material of modified D’Astolfo to be provided in a gradient in a lateral direction as taught by Li to provide increased resistance from electrolyte corrosion with increased ceramic content at the exposed upper end and good thermal shock resistance with increased metal content adjacent the metal filler at the lower end.
Regarding claim 20, D’Astolfo as modified by Li teaches the gradient being configured such that the concentration of said aggregate is higher adjacent to an upper end of the anode body as compared to adjacent to a lower end of the anode body (see e.g. D’Astolfo Fig. 1, exposed upper end of seal 18; see e.g. Li Paragraph 0011, lines 1-3, Paragraph 0013, lines 1-6, Paragraph 0016, lines 2-4 relative contents of ceramic and metal phases varied in the axial, i.e. up and down, direction, with higher ceramic content providing resistance to electrolyte corrosion for exposed portions, such as the exposed upper end of the seal of D’Astolfo).
Regarding claim 21, D’Astolfo as modified by Li teaches the gradient being configured such that the concentration of said aggregate is lower adjacent to an upper end of the anode body as compared to adjacent to a lower end of the anode body (see e.g. D’Astolfo Fig. 1, lower end of seal 18 in contact with metal filler 16, Paragraph 0017, lines 7-9, and Paragraph 0019; see e.g. Li Paragraph 0011, lines 1-3, Paragraph 0013, lines 1-6, Paragraph 0016, lines 2-4, relative contents of ceramic and metal phases varied in the axial, i.e. up and down, direction, with higher metal content adjacent a metal component, such as the metal filler of D’Astolfo, providing good thermal shock resistance).
Regarding claim 22, the limitation of the concentration being “higher…at a position adjacent to the bath-vapor interface” is a statement of intended use of the apparatus, as it claims features related to the process in which the apparatus is used, namely the depth of the anode in the bath. MPEP § 2114 II states ‘"[A]pparatus claims cover what a device is, not what a device does."…A claim containing a "recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus" if the prior art apparatus teaches all the structural limitations of the claim.”. D’Astolfo as modified by Li teaches the concentration of sealing material varying in a lateral, i.e. up and down, direction of the anode body, as stated above with respect to claim 19, so it would be capable of having the higher concentration of a sealing material at the bath-vapor interface. Further, Adler teaches corrosion of the anode being greatest at the level of the interface between the electrolyte and surrounding atmosphere (see e.g. Adler Col. 4, lines 30-40), providing additional motivation for having the higher concentration of corrosion protective sealing material at said interface.
Claims 24 and 31-33 are rejected under 35 U.S.C. 103 as being unpatentable over D’Astolfo in view of Martin et al. (U.S. 2016/0326661), and further in view of Adler, Clark and Crottaz; claim 24 evidenced by D’Astolfo2.
Regarding claim 24, D’Astolfo teaches an electrolysis cell (see e.g. Paragraph 0001 and Paragraph 0041, lines 13-15, electrolytic metal production cell, such as aluminum production cell), comprising:
a cell structure comprising a control volume is configured to retain a molten electrolyte bath (see e.g. Paragraph 0008, lines 2-5, and Paragraph 0041, lines 14-15, electrolytic molten salt bath); and
anode assembly (see e.g. Fig. 1, anode assembly 10; Paragraph 0017, lines 1-2) configured to direct current into the molten electrolyte bath (see e.g. Paragraph 0008, lines 2-5), wherein the anode assembly comprises:
an anode apparatus (see e.g. Paragraph 0017, lines 3-5) comprising:
(a) an anode body comprising at least one outer sidewall, wherein the at least one outer sidewall is configured to define a shape of the anode body (see e.g. Fig. 1, outer wall defining cup-shaped inert anode 12; Paragraph 0017, lines 3-5), and to perimetrically surround a hole in the anode body (see e.g. Fig. 1, hole defined by interior walls of anode 12), wherein the hole comprises an upper opening in a top surface of the anode body and wherein the hole axially extends into the anode body (see e.g. Fig. 1, opening at upper part of anode 12 which extends downward forming the hole);
(b) a pin (see e.g. Fig. 1, conductor rod 14; Paragraph 0017, lines 4-5) comprising:
a. a first end connected to a current supply (see e.g. Fig. 1, exposed upper end of conductor rod 14 connects to power supply; Paragraph 0043, lines 8-10), and
b. a second end opposite the first end, wherein the second end extends downward into the upper opening of the anode body and into the hole of the anode body (see e.g. Fig. 1, lower end of conductor rod 14 extends into the anode body 12);
(c) a filler material inside the hole and configured to electrically connect the anode body to the pin (see e.g. Fig. 1, particulate connector material 16; Paragraph 0017, lines 5-7, and Paragraph 0029, lines 1-3), wherein the filler material is retained in the hole between an inner sidewall of the anode body and the pin (see e.g. Fig. 1, connector material 16 fills the gap G between the inner anode surface and the conductor rod; Paragraph 0017, lines 5-7); and
(d) a sealing material configured to reduce corrosion of the anode apparatus (see e.g. Fig. 1, seal 18 which seals off the inner portion of the anode body, and thereby prevents or reduces exposure of contained anode parts to potential corrosion; Paragraph 0017, lines 7-9), the sealing material comprising an aggregate and a matrix (see e.g. Paragraph 0027, the sealing material may be a castable ceramic or cermet, meeting the definition of an aggregate and a matrix as per paragraph 0084 of the instant specification), the aggregate being an anode-matched aggregate (see e.g. Paragraphs 0027, lines 2-6, and Paragraph 0036, lines 1-4, both the seal and the inert anode comprise ceramic or cermet materials, with aluminum oxide particularly present in both), wherein the sealing material covers at least a portion of:
an inner sidewall of the anode body, the pin and the filler material (see e.g. Fig. 1, seal 18 covers the upper inner wall of anode 12, a portion of conductor 14 at the top of the anode, and the top of the connector material 16); and
wherein the sealing material is configured to enclose the filler material into the anode body between the inner sidewall of the anode body and the pin (see e.g. Fig. 1, seal 18 seals connector material 16 into the anode body 12; Paragraph 0017, lines 7-9);
wherein the sealing material comprises a castable ceramic or cermet comprising Al2O4, SiO2, MgO, CaO and/or NaO (see e.g. Paragraph 0027, lines 2-4); and
wherein said anode matched aggregate comprising aggregates having a composition 70% of a major compound of the anode body (see e.g. Paragraph 0027, lines 4-6, and Paragraph 0036, lines 3-8, Al2O3 being a major compound of the anode body and the seal material comprising Beta 70 castable sold by Permatech which has 70% Al2O3, as evidenced by D’Astolfo2 Paragraph 0035).
D’Astolfo does not explicitly teach the cell structure comprising a cell bottom and a cell sidewall, wherein the cell sidewall is configured to perimetrically surround the cell bottom and extend in an upward direction to define the control volume.
Martin teaches an aluminum electrolysis cell (see e.g. Paragraph 0001) comprising a cell structure comprising a cell bottom and a cell sidewall, wherein the cell sidewall is configured to perimetrically surround the cell bottom and extend in an upward direction to define a control volume (see e.g. Fig. 1, pot shell 2 with upwardly extending sidewalls perimetrically surrounding a bottom, defining a volume therein; Paragraph 0086, lines 1-2), wherein the control volume is configured to retain a molten electrolyte bath (see e.g. Fig. 1, electrolytic bath 12 in pot shell 2; Paragraph 0087, lines 3-4).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the cell of D’Astolfo to comprise a structure including a cell bottom and an upwardly extending cell sidewall perimetrically surrounding the cell bottom as taught by Martin as a suitable structure for retaining the molten electrolyte bath of an aluminum electrolysis cell. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
D’Astolfo as modified by Martin above does not explicitly teach an anode support to which the anode apparatus is mechanically attached.
Martin further teaches an anode assembly including at least one anode block supported by an anode support (see e.g. Fig. 1, anode block 10 supported by anode support 8; Paragraph 0086, lines 7-9), the support comprising a horizontal support bar connected to stubs sealed within holes in the anode block (see e.g. Fig. 1, support bar 80 and stubs 81; Paragraph 0086, lines 9-15), similar to the conductor rod of D’Astolfo (see e.g. D’Astolfo Fig. 1, conductor rod 14 extending into the anode body 12). This horizontal support bar also forms a portion of the electrical conductor leading electrolysis current to the anode assembly (se e.g. Paragraph 0098), allowing the cell to free of a support other than the electrical conductor that may affect sealing of the cell chamber (see e.g. Paragraphs 0038-0039).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the anode assembly of D’Astolfo in view of Martin to further comprise an electrically conducting horizontal support bar to which the conductor rods/pins are connected as taught by Martin to provide electrolysis current and support to the anode assembly without use of additional support devices that may affect sealing of the cell. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Modified D’Astolfo does not teach the sealing material being bonded to and covering the top surface of the anode body and extending beyond a peripheral edge of the top surface and covering a portion of the at least one outer sidewall of the anode body configured to be positioned in a vapor space above the molten electrolyte bath, such that the sealing material extends down the at least one outer sidewall and terminates at a portion of the at least one outer sidewall configured to be proximate to a bath-vapor interface and located at or above the bath-vapor interface, the sealing material further covering at least a portion of the anode support, and the sealing material being retained above the top surface of the anode body.
Alder teaches a ceramic anode for molten electrolysis (see e.g. Abstract), which is provided with a protective layer that is bonded to the top surface and may extend partially down the sidewalls of the anode body to a three phase zone interface between the electrolyte and surrounding atmosphere (see e.g. Figs. 1-2 and 4, protective layer 2 bonded to upper surfaces and at least part of sidewalls of anode 3 in three phase zone, which may only cover to the extent that the three phase zone is protected, i.e. extending only to/terminating at said zone interface; Col. 3, lines 8-13, Col. 4, lines 35-40, and Col. 6, lines 25-30, 36-39 and 62-63), may extend into a horizontal support for the anode (see e.g. Fig. 9, protective layer 2 extending along power lead 1 into horizontal top 14 of cell through which anode assemblies extend), and serves to protect these surfaces from corrosion (see e.g. Col. 5, lines 23-32), the protective layer comprising a material which is resistant to attack by the molten electrolyte (see e.g. Col. 6, lines 20-22), such as Al2O3 (see e.g. Col. 6, lines 25-28), which is also a main component of the sealing material taught by D’Astolfo (see e.g. D’Astolfo Paragraph 0027, lines 1-4).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the sealing material taught by D’Astolfo in view of Martin to be bonded to and cover the top surface and extend partially down the sidewalls of the anode body to terminate at a three phase zone interface between the electrolyte and surrounding atmosphere and additionally cover a portion of the anode support as taught by Alder to provide these surfaces with protection from corrosion by the molten electrolyte.
Modified D’Astolfo does not explicitly teach the sealing material having a coefficient of thermal expansion that substantially overlaps with a coefficient of thermal expansion of the anode body. D’Astolfo does however teach both the anode body and the sealing material comprising conductive ceramic or cermet materials (see e.g. D’Astolfo Paragraph 0027, lines 1-2, and Paragraph 0036, lines 1-6).
Clark teaches an anode for aluminum electrolysis (see e.g. Abstract) comprising a conductive core composed of a first conductive ceramic material covered by an adherent coating of a second conductive ceramic material having a closely matching coefficient of thermal expansion to the first conductive ceramic material (see e.g. Fig. 1, core 11 with adherent coating 12; Col. 3, lines 51-65), the coating protecting the anode core by providing corrosion resistance above and below the melt as well as at the melt/ambient interface (see e.g. Col. 3, lines 17-21, and Col. 6, lines 19-21), and the closely matching coefficients of thermal expansion preventing destruction of the anode during use (see e.g. Col. 4, lines 22-28).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the corrosion protecting sealing material of modified D’Astolfo to have a coefficient of thermal expansion closely matching that of the anode body as taught by Clark to protect the surfaces of the anode body by providing corrosion resistance while preventing destruction of the anode during use.
Modified D’Astolfo does not teach at least some of the silicates and/or aluminates of said castable ceramic or cermet being replaced with an aggregate specifically tailored to match the anode body and/or the pin, wherein the aggregate is specifically tailored to not undergo chemical reactions with the anode body and/or pin. D’Astolfo does however teach the anode comprising ceramic materials such as nickel, aluminum and/or zinc oxides (see e.g. D’Astolfo Paragraph 0036, lines 1-6), as well as the sealing material comprising predominantly aluminum oxide (see e.g. D’Astolfo Paragraph 0027, lines 1-4, the seal material comprising Beta 70 castable sold by Permatech which has 70% Al2O3, as evidenced by D’Astolfo2 Paragraph 0035).
Crottaz teaches a coating for protecting an anode conductor in an aluminum electrowinning cell from cell gases (see e.g. Abstract), the coating being a ceramic coating made predominantly of aluminum oxide and containing at least one other ceramic compound such as oxides of nickel and zinc (see e.g. Page 4, lines 18-24, and Page 5, lines 5-7), these compounds being resistant to fluorides and not significantly reducing the protective capacity of alumina against cell gases (see e.g. Page 4, lines 25-29), and thereby having stability against reactions with other anode structure components (see e.g. Page 5, lines 17-19, and Page 9, lines 19-23, coating resistant to oxidation and corrosion by reactive gases, the high alumina content providing high chemical stability; this resistance to reactive gases that would cause the sealing material to corrode the pin or reduce the structural integrity of the anode body being what is similarly exemplified in paragraphs 0143-0145 of the instant specification as “not undergo[ing] significant reactions”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the ceramic sealing material of modified D’Astolfo to comprise, in addition to the major aluminum oxide component, another ceramic compound such as nickel or zinc oxide, which may also be present in the anode, as taught by Crottaz to provide resistance to fluoride gases in the cell without significantly reducing the protective capacity of the aluminum oxide against cell gases.
Regarding claim 31, D’Astolfo as modified by Adler teaches the molten electrolyte bath contained within the control volume, with the vapor space located above the molten electrolyte bath, wherein the sealing material terminates at and proximate to the bath-vapor interface (see e.g. D’Astolfo Paragraph 0008, lines 2-5, and Paragraph 0041, lines 14-15, electrolytic molten salt bath; see e.g. Adler Col. 4, lines 35-40, and Col. 6, lines 36-39, anode sidewalls may be partially covered with protective material only to extent that three phase zone interface between the electrolyte and surrounding atmosphere is protected, i.e. extending only to/terminating at said interface).
Regarding claim 32, modified D’Astolfo teaches the sealing material providing structural support to the anode assembly (see e.g. D’Astolfo Paragraph 0027, lines 8-10, seal provides mechanical support to the anode).
Regarding claim 33, modified D’Astolfo teaches the sealing material providing the structural support by providing mechanical attachment of the anode body to the pin (see e.g. D’Astolfo Paragraph 0027, lines 8-10, seal provides mechanical support by transferring weight of the anode to the conductor rod, i.e. via mechanical attachment therebetween).
Response to Arguments
Applicant's arguments filed 03/25/2026 have been fully considered but they are not persuasive.
On pages 10-11, Applicant argues that the cited references, namely D’Astolfo and Adler, do not disclose a sealing material that provides mechanical attachment or other structural reinforcement. This is not considered persuasive. Upon closer consideration, D’Astolfo teaches the seal provides mechanical support to the anode by transferring weight of the anode to the conductor rod, i.e. via mechanical attachment therebetween (see e.g. D’Astolfo Paragraph 0027, lines 8-10).
On pages 11-12, Applicant argues that the cited references do not teach the sealing material terminating at a point at or above the vapor-bath interface, particularly as Adler discloses coating formed in situ that are only shown extending below the liquid-bath interface and other exemplified layers in the Figures of Adler also extend below the interface. This is not considered persuasive. Though not explicitly shown in the Figures, Adler teaches that the protective/sealing material may extend down the sidewall only to the extent that the three phase interface with the electrolyte and atmosphere is protected, i.e. may terminate at said interface (see e.g. Adler Col. 4, lines 35-40, and Col. 6, lines 36-39). It should be noted that Adler is not limited to the in situ protective coating formation, and further teaches that the protective coating may be a pre-shaped covering (see e.g. Adler Col. 5, lines 34-38).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Johnson (U.S. Patent No. 3,738,918) discloses an anode for aluminum electrolysis configured to be partially submerged in electrolyte, wherein a protective coating is provided only on the tops and sides of the anode body above the electrolyte that are exposed to atmospheric oxidation.
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/MOFOLUWASO S JEBUTU/Examiner, Art Unit 1795
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