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 § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-5, 12-16, 19 and 20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Zhang (“A Critical Review on Secondary Lead Recycling Technology and its Prospect”; Renewable and Sustainable Energy Reviews; 61; pages 108-122; 2016).
Regarding claim 1, Zhang discloses an electrochemical lead recovery plant (abstract), comprising:
a thermal pretreatment unit operationally coupled to an electrolytic lead
recovery unit (a pyrometallurgical step is followed by electrowinning – abstract; page 112, section 3.1.2 to page 113, section 3.2);
wherein the thermal pretreatment unit/pyrometallurgical step comprises a thermal reactor that is configured to continuously receive lead paste comprising lead oxide, lead dioxide, and lead sulfate, and to continuously produce a thermally treated lead paste (page 112, section 3.1.2);
wherein the thermal pretreatment unit is further configured to thermally convert at least 70% of all lead dioxide in the lead paste to an oxide other than lead dioxide (the lead dioxide is reduced before the electrowinning step; page 112, section 3.1.2 to page 113, section 3.2);
wherein the electrolytic lead recovery unit comprises a dissolving unit
fluidly coupled to an electrolyzer unit (page 114, col. 1, paragraphs 1-3);
wherein the dissolving unit contains a recycled electrolyte (figures 9, 11 show a recycling loop) and is coupled to the thermal pretreatment unit to receive and dissolve the thermally treated lead paste in the recycled electrolyte to thereby form a lead ion enriched electrolyte (pages 113-114, section 3.2; page 115, section 3.3.2); and
wherein the electrolyzer unit is configured to receive the lead ion enriched
electrolyte, to continuously produce high purity lead from the lead ion enriched electrolyte (page 112, section 3.1.2 to page 113, section 3.2; page 117, col. 1, first paragraph), and to form the recycled electrolyte (figures 9, 11 show a recycling loop).
Regarding claim 2, Zhang further teaches a desulfurization unit operationally coupled to the thermal pretreatment unit and configured to convert lead sulfate to soluble sodium sulfate and insoluble lead hydroxide and/or lead carbonate (pages 115-116, section 3.3.2).
Regarding claim 3, the desulfurization unit of Zhang further includes a wash unit configured to wash the lead paste after desulfurization (figure 11).
Regarding claim 4, Zhang discloses wherein the desulfurization unit further includes a filter press configured to reduce water content of the lead paste after desulfurization (page 113, section 3.2).
Regarding claim 5, Zhang teaches wherein the washed desulfurized lead paste contains residual sulfates in an amount of less than 1 wt % (figure 7).
Regarding claim 12, Zhang discloses wherein the thermal pretreatment unit is configured to thermally convert at least 80% of all lead dioxide in the lead paste to an oxide other than lead dioxide (the lead dioxide is reduced before the electrowinning step; page 112, section 3.1.2 to page 113, section 3.2).
Regarding claim 13, Zhang discloses wherein the thermal pretreatment unit is configured to thermally convert at least 90% of all lead dioxide in the lead paste to an oxide other than lead dioxide (the lead dioxide is reduced before the electrowinning step; page 112, section 3.1.2 to page 113, section 3.2).
Regarding claims 14-15, Zhang teaches wherein the recycled electrolyte comprises an alkane sulfonic acid, i.e. methane sulfonic acid (page 115, section 3.3.2).
Regarding claim 16, Zhang further discloses wherein the dissolving unit is configured to allow removal of solids from the lead ion enriched electrolyte and/or the recycled electrolyte, wherein the solids are lead dioxide, and/or lead sulfate (page 112, section 3.1.2; pages 113-114, section 3.2.1).
Regarding claim 19, the high purity lead of Zhang has a purity of at least 95% (page 117, col. 1, first paragraph – purity of 99.999%).
Regarding claim 20, wherein the high purity lead of Zhang has a purity of at least 99% (page 117, col. 1, first paragraph – purity of 99.999%).
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 non-obviousness.
Claims 6-9 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang as applied to claim 1 above, and further in view of Spence et al. (US Patent Application Publication no. 2015/0367311).
Regarding claims 6-7, Zhang discloses all the features discussed above, but fails to teach wherein the thermal pretreatment unit comprises a fluidized bed reactor, a conveyor belt furnace, or a rotating kiln.
Spence teaches a process for recycling lead comprising a heating step in a rotary kiln to facilitate the movement and mixing of a lead salt precipitate through the length of the furnace and uniformly heat the lead salt precipitate into lead oxide particles (paragraph 46).
It would have been obvious to one having ordinary skill in the art at the time of filing to use a rotating kiln as the thermal pretreatment unit of Zhang, as taught by Spence, in order to facilitate the movement and mixing of a lead salt precipitate through the length of the furnace and uniformly heat the lead salt precipitate into lead oxide particles.
Regarding claims 8-9, rotary kiln of Spence is configured to heat the lead paste to a temperature of up to 500° C (paragraph 30). Spence further teaches process controls to determine optimum temperatures and times of operation (paragraph 28). 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.
Regarding claim 10, Spence further suggests wherein the thermal pretreatment unit is configured to reduce residual water in the thermally treated lead paste to equal or less than 5 wt % of the dried decomposed desulfurized lead paste (the paste is partially wet or completely dried – paragraph 45).
Regarding claim 11, Spence suggests wherein the thermal pretreatment unit is configured to reduce residual water in the thermally treated lead paste to equal or less than 2 wt % of the dried decomposed desulfurized lead paste (the paste is partially wet or completely dried – paragraph 45).
Claims 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang as applied to claim 1 above, and further in view of Clarke et al. (US Patent Application Publication no. 2018/0127852).
Regarding claim 17, Zhang discloses all the features discussed above, but fails to teach wherein the electrolyzer unit comprises a moving cathode.
Clarke teaches a method for recovery of lead comprising an electrochemical step wherein the cathode can exhibit rotational movement while the electrical potential is applied such that the lead deposited on the cathode is removed from the lead ion solution (paragraph 15).
It would have been obvious to one having ordinary skill in the art at the time of filing to use a moving cathode in the electrolyzer unit of Zhang, as taught by Clarke, in order to effectively remove the lead deposited on the cathode to provide a continuous lead recovery operation.
Regarding claim 18, the moving cathode of Clarke is configured to allow reduction of lead ions on one portion of a cathode and contemporaneous removal of metallic lead from another portion of the cathode (paragraphs 15, 40, 44).
Conclusion
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
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