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 .
Response to Amendment
The amendment filed on 12/04/2025 has been entered. Claims 1-25 are pending in the application. Applicant’s amendments to the claims have overcome each 112(b) rejection previously set forth in the office action mailed 06/04/2025.
Response to Arguments
Applicant's arguments filed 12/04/2025 have been fully considered but they are not persuasive.
Applicant argues on Pg. 7 paragraphs 1-3 that the material which is contacted with the hydroxide base is not a lead-containing waste as defined in the specification i.e. extracted from a waste source and not significantly chemically processed. The steps disclosed by Smith A-D significantly modify the chemical composition of the waste with the result that all lead is present in its +2 oxidation state in the form of a chloride, sulfate or oxide. The instant specification discusses how typical lead-containing wastes contain a variety of lead compounds and valencies, including lead dioxide and metallic lead, which is not the case for the material in Smith, which is slurried with a hydroxide base.
However, Smith discloses the present invention provides… chemical process… which directly converts lead compounds and mixtures of lead compounds with mixed oxidation states (0, 2, 3, and 4) and even contaminated with finely divided lead metal, i.e. metallic lead, directly into high purity PbO (Col. 3 lines 51-56). Mixtures of lead compounds with mixed oxidation states (0, 2, 3, and 4) is interpreted as including metallic lead (oxidation state 0) and PbSO4 (oxidation state 2). Smith does disclose steps which are not claimed in the instant application, however, the claim language of claim 1 “method comprising” does not disqualify additional steps. Therefore, the disclosure of Smith meets all the claim limitations of claim 1.
Applicant argues on Pg. 9 paragraph 2-3 that maintaining a pH of 11 to 15 during desulfurization is a key concept underlying amended claim 1.
However, Applicant's arguments fail to comply with 37 CFR 1.111(b) because they amount to a general allegation that the claims define a patentable invention without specifically pointing out how the language of the claims patentably distinguishes them from the references.
Applicant argues on Pg. 10 par. 2 that Smith’s disclosure of the pH maintenance is entirely oriented around converting the lead oxide product obtained from desulfurization directly into battery pastes, which is not relevant to the products of amended claim 1, which are generally processed further downstream.
However, Smith discloses the pH… was maintained at 13-14 (Col. 5 lines 42-43) which lies within the claimed range of from 11 to 15. Smith maintains this pH during the step of treating the waste with potassium hydroxide and therefore meets the claim limitation.
Applicant argues on Pg. 10 paragraph 3 that there is no suggestion in Smith that a pH ≥ 13 causes the selective conversion of lead sulfate into lead (II) oxide without formation of lead hydroxide; rather Smith presents a pH ≥ 13 and the formation of lead (II) oxide as separate consequences of using a hydroxide base.
However, Applicant's arguments fail to comply with 37 CFR 1.111(b) because they amount to a general allegation that the claims define a patentable invention without specifically pointing out how the language of the claims patentably distinguishes them from the references.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1-3, 5-7, 9, 17, 21 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Smith et al (US 7785561, cited in IDS 03/27/2023).
Regarding claim 1, Smith discloses a process for producing high purity lead oxide from waste lead products such as waste battery paste (Col 2 lines 57-59). The present invention provides… chemical process… which directly converts lead compounds and mixtures of lead compounds with mixed oxidation states (0, 2, 3, and 4) and even contaminated with finely divided lead metal, i.e. metallic lead, directly into high purity PbO (Col. 3 lines 51-56). Mixtures of lead compounds with mixed oxidation states (0, 2, 3, and 4) is interpreted as lead-containing waste comprising metallic lead (oxidation state 0) and PbSO4 (oxidation state 2). The wet filter cake from the first step is slurried in an equal amount of water, i.e. an aqueous slurry of the lead-containing waste, and sufficient 45% potassium hydroxide (30% by weight of lead compound) or equivalent sodium hydroxide solution is added to convert all lead compounds to PbO and maintain the solution at pH ≥13 (Col 4 lines 34-39, meeting limitations “said method comprising: (a) treating an aqueous slurry of the lead-containing waste with a hydroxide base thereby forming desulfurised lead-containing waste in which PbSO4 has been converted to PbO and an aqueous solution comprising sulfate anions”. Smith further discloses the pH was checked periodically to be sure that it was maintained a 13-14 (Col 5 lines 42-43). The pH disclosed by Smith, 13-14, lies within the claimed range of from 11 to 15. The solution is heated to 100 °C., stirred two hours and then filtered (Col 4 lines 39-40, meeting limitation “and (b) separating the desulfurised lead-containing waste from the aqueous solution comprising sulfate anions”).
Regarding claim 2, Smith discloses all the limitations in the claims as set forth above including the present invention provides… chemical process… which directly converts lead compounds and mixtures of lead compounds with mixed oxidation states (0, 2, 3, and 4) and even contaminated with finely divided lead metal directly into high purity PbO (Col. 3 lines 51-56). Mixtures of lead compounds with mixed oxidation states (0, 2, 3, and 4) meets the claim limitation of PbO (oxidation state 2) and PbO2 (oxidation state 4).
Regarding claim 3, Smith discloses all the limitations in the claims as set forth above including a process for producing high purity lead oxide from waste lead products such as waste battery paste (Col 2 lines 57-59).
Regarding claim 5, Smith discloses all the limitations in the claims as set forth above including the pH was checked periodically to be sure that it was maintained a 13-14 (Col 5 lines 42-43). The pH disclosed by Smith, 13-14, lies within the claimed range of from 11.5 to 14.5.
Regarding claim 6-7, Smith discloses all the limitations in the claims as set forth above including the wet filter cake is slurried in an equal amount of water and sufficient 45% potassium hydroxide or equivalent sodium hydroxide solution is added to convert all lead compounds to PbO and maintain the solution at pH ≥13 (Col 4 lines 34-39, meeting limitations “wherein the pH is maintained during step (a) by further addition of the hydroxide base to the aqueous slurry”(claim 6) and “wherein the base is a metal hydroxide base”(claim 7)).
Regarding claim 9, Smith discloses all the limitations in the claims as set forth above including the wet filter cake is slurried in an equal amount of water (Col 4 lines 34-39). In example 1, the damp white cake is repulped in 100 ml water (Col 5 line 39), which is equivalent to 100 g of water. Equal amount of wet filter cake is 100 g, and about 100 g of solids content. Therefore, the slurry has solids content of about 50% which is within the claimed range of from 30 to 80% by weight.
Regarding claim 17, Smith discloses all the limitations in the claims as set forth above including the solution is heated to 100 °C., stirred two hours and then filtered (Col 4 lines 39-40, meeting limitation “the desulfurised lead-containing waste is separated from the aqueous solution comprising sulfate anions using filtration”).
Regarding claim 21, Smith discloses a process for producing high purity lead oxide (abstract). Analysis of the off-white solid showed sulfate, 20 ppm… the overall purity was 99.9+% by weight (Col 5 lines 53-57, meeting limitation “the desulfurised lead-containing waste which is obtained at the end of step (b) comprises: PbSO4 in an amount of less than 1 % by weight; lead hydroxide forms in an amount of less than 1 % by weight; PbCO3 in an amount of less than 2 % by weight; and/or PbO in an amount of at least 40 by weight”).
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Smith et al (US 7785561, cited in IDS 03/27/2023), in view of Pan et al (US 2016/0160316 A1, hereinafter "Pan '316").
Smith discloses all the limitations in the claims as set forth above but is silent to “wherein the hydroxide base is consumed in step (a) in an amount of from 1.9 to 2.1 moles per mole of lead sulfate in the lead-containing waste”.
Pan ‘316 discloses a method for directly recovering lead oxide for negative electrode of lead- acid battery from waste lead paste ([0001]). The lead oxide recovery process is as follows ([0059]) mix the 2 kg waste lead paste with 2L NaOH solution of 8.9 wt.% concentration ([0060]) where the weight percentages of the main components in the waste lead paste are… 37%PbSO4 ([0058]).
NaOH
Density of NaOH solution = 1.09 kg/L
2L of 8.9% = 0.194 kgNaOH
Molar mass 39.997 g/mol
4.85 mol
4.85/2.11=
1.99
PbSO4
37 % of 2 kgpaste = 0.74 kgPbSO4
Molar mass 303.26 g/mol
2.11 mol
Therefore, the ratio disclosed by Pan ‘316 (1.99) lies within the claimed range of from 1.9 to 2.1.
Pan ‘316 further discloses if the amount of desulfurizing agent (NaOH) is inadequate, some PbSO4 will remain, and the desulphurization effect will be compromised; if the added amount of desulfurizing agent is excessive, the residual desulfurizing agent will cause PbO dissolution and increased Pb content in the filtrate ([0045]).
Thus, prior to the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art for the hydroxide base to be consumed in step (a) in an amount of from 1.9 to 2.1 moles per mole of lead sulfate in the lead-containing waste in the method of Smith in order to avoid PbSO4 remaining and compromising the desulphurization effect while avoiding PbO dissolution and increased Pb content in the filtrate as taught by Pan ‘316.
Claims 10-12, 20 are rejected under 35 U.S.C. 103 as being unpatentable over Smith et al (US 7785561, cited in IDS 03/27/2023), in view of Pan et al (EP 3012334 A1, cited in IDS 03/27/2023, hereinafter "Pan '334").
Regarding claims 10-12, 14, 20 Smith discloses all the limitations in the claims as set forth above but is silent to “wherein step (a) is carried out at a temperature of from 0 to 70 °C” (claim 10), “wherein the lead-containing waste is comminuted during step (a)” (claim 11), “wherein step (a) is carried out in a mill” (claim 12), and “wherein: at least 95 % of the sulfur is removed from the lead-containing waste; and/or at least 95 of the lead that was present in the lead-containing waste used in step (a) is retained” (claim 20).
Pan ‘334 discloses a method for directly recovering lead oxide from waste lead paste of lead-acid batteries ([0040]). The lead oxide recovery process is as follows: (1) mix the 10kg waste lead paste with 15L 8.5 wt.% NaOH solution at 20°C, and carry out ball milling (based on 1,000g waste lead paste, the mass of the balls is 300g, agate balls are used) for 10min, and then filter to obtain filtrate and filter residue ([0041]). Pan ‘334 discloses the lead recovery rate is 99.8% ([0044] meeting limitation “at least 95 of the lead that was present in the lead-containing waste used in step (a) is retained”). Pan ‘334 further discloses by controlling the lead oxide-containing waste and the desulfurizing agent to mix and contact in the wet ball milling process, a more homogeneous stirred milling effect can be attained more quickly when compared with the conventional stirred mixing process in a reactor, the yield rate of PbO and the purity of PbO product can be greatly improved subsequently, and the time required for the contact can be shortened ([0017]).
Thus, prior to the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to carry out step (a) at a temperature from 0 to 70 °C, wherein the lead-containing waste is comminuted in a mill during step (a) wherein the mill is operated as a closed circuit mill, and at least 95 of the lead that was present in the lead-containing waste used in step (a) is retained in the method of Smith in order for a more homogeneous stirred milling effect to be attained more quickly, the yield rate of PbO and the purity of PbO product can be greatly improved subsequently, and the time required for the contact to be shortened as taught by Pan ‘334.
While not indefinite, use of the words “and/or” in claim 20 does not constitute both aspects necessarily required by the claim and both are not considered as required in the above rejection over Smith in view of Pan ‘334.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Smith et al (US 7785561, cited in IDS 03/27/2023), in view of Pan et al (EP 3012334 A1, cited in IDS 03/27/2023) and in further view of Wu (CN 107245581A).
Smith in view of Pan discloses all the limitations of claim 12 as set forth above but is silent to “wherein the mill is operated at a speed of from 5 to 60 rpm”.
Wu discloses a method for treating battery industrial waste, and more particularly to a method for recycling acid-leached lead mud ([0002]). The solid phase material lead mud uses waste lead slag as grinding medium and sodium hydroxide solution as desulfurizer ([0010]). It is mixed and ground for desulfurization on the grinding equipment ([0010]). Preferably, the grinding equipment used is a horizontal ball mill ([0016]). Preferably, the rotation speed of the horizontal ball mill is controlled at 58-62 r/min… which has the advantages of both working efficiency and energy saving ([0017]).
As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). In the instant case, the range taught by Wu (58-62 r/min) overlaps with the claimed range (5 to 60 rpm). Therefore, the range in Wu renders obvious the claimed range.
Thus, prior to the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to operate the mill at a speed of from 5 to 60 rpm in the method of Smith in view of Pan in order to have both working efficiency and energy saving as taught by Wu.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Smith et al (US 7785561, cited in IDS 03/27/2023), in view of 911 Metallurgist (“Closed Circuit Grinding VS Open Circuit Grinding”, from https://www.911metallurgist.com/blog/closed-grinding-circuits-vs-open-grinding-circuits/)
Smith discloses all the limitations in the claims as set forth above but is silent to “wherein the mill is operated: in a continuous mode; and/or as a closed circuit mill”.
911 Metallurgist discloses closed circuit grinding consists of one or more mills discharging ground product to classifiers which in turn return the coarse product from the size separation back to the mill for further grinding (Pg. 6 paragraph 1). This type of grinding is the most common circuit found in mineral processing facilities… some advantages presented by grinding in closed circuit are that this arrangement usually results in higher mill capacity and lower power consumption per ton of product, it eliminates overgrinding by removing fines early and it avoids coarse material in the final ground product by returning this material to the mill (Pg. 6 paragraph 2).
Thus, prior to the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art for the mill to be operated: in a continuous mode; and/or as a closed circuit mill in the method of Smith in order to obtain higher mill capacity and lower power consumption per ton of product, and to eliminate overgrinding and avoid coarse material in the final ground product as taught by 911 Metallurgist.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Smith et al (US 7785561, cited in IDS 03/27/2023), in view of Zhang et al (“Structural study of a lead (II) organic complex- a key precursor in a green recovery route for spent lead-acid battery paste”).
Smith discloses all the limitations in the claims as set forth above but is silent to “wherein a conditioning step is carried out between steps (a) and (b), the conditioning step comprising: leaving the desulfurised lead-containing waste and the aqueous solution comprising sulfate ions that are formed in step (a) in a tank for a period of time; and/or then adding water to the desulfurised lead-containing waste and the aqueous solution comprising sulfate ions that is formed in step (a)”.
Zhang discloses a method of lead recycling… spent lead paste was treated with aqueous citric acid solution… to recycle PbO/Pb products from the starting material of PbO, PbO2, and PbSO4 (Pg. 672 right col.). Lead sulfate was leached (Pg. 673 right col. par. 1). After leaching, the reaction vessel with the reactant slurry was immersed in a water bath at 55 °C for 8 h crystallization (Pg. 673 right col. par. 2). The lead citrate products after conditioning were rinsed with distilled water (Pg. 673 right col. par. 2). Zhang further discloses a more uniform crystal shape and larger crystal size after conditioning (Pg. 676 right col. Par. 2).
Thus, prior to the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to carry out a conditioning step between steps (a) and (b), the conditioning step comprising: leaving the desulfurised lead-containing waste and the aqueous solution comprising sulfate ions that are formed in step (a) in a tank for a period of time; and then adding water to the desulfurised lead-containing waste and the aqueous solution comprising sulfate ions that is formed in step (a) in the method of Smith in order to produce a more uniform crystal shape and larger crystal size after conditioning as taught by Zhang.
Claim 18-19 are rejected under 35 U.S.C. 103 as being unpatentable over Smith et al (US 7785561, cited in IDS 03/27/2023), in view of Garcia et al ("Determination of Sulfate by Conductometric Titration: An Undergraduate Laboratory Experiment").
Smith discloses all the limitations in the claims as set forth above and further discloses the filter cake was washed … with Dl water until the filtrate was pH 7-8 (Col 5 lines 47-49, meeting limitation “wherein step (b) comprises washing the desulfurised lead- containing waste with water”). However, Smith is silent to “monitoring the sulfate content of the used wash water to determine when a target level of sulfate has been achieved” (claim 18) and “wherein monitoring comprises measuring the conductivity of the used wash water” (claim 19).
Garcia discloses a titrimetric procedure used for sulfate determination is conductometric titration, also known as conductometry (Pg. 910 right col bottom paragraph). This method monitors the conductivity of a solution (Pg. 911 left column top paragraph).
It would be obvious to one having ordinary skill in the art to use a commonly known practice, such as conductometric sulfate titration, to determine the sulfate level in solution.
Thus, prior to the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to monitor the sulfate content of the used wash water to determine when a target level of sulfate has been achieved, wherein monitoring comprises measuring the conductivity of the used wash water in the method of Smith as taught by Garcia.
Conclusion
THIS ACTION IS MADE FINAL. 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.
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/N.L.Q./Examiner, Art Unit 1738
/MICHAEL FORREST/Primary Examiner, Art Unit 1738