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 and Status of Claims
Applicant’s amendments to the claims, filed November 26, 2025, is acknowledged. Claim 1 is amended. No new matter has been added.
Claims 1-12 are currently pending and considered in this office action.
Claim Objections
Claim 1 is objected to because of the following informalities:
“2) sequentially adding a mixed ammonium magnesium reagent and a hydrophobic macromolecular organic matter having a periodic geometric structure into the arsenic-containing alkaline leaching solution, and taking a reaction under a stirring to obtain complex arsenate crystals cladded with an organic matter. wherein the mixed ammonium magnesium reagent is comprised of a carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter, a magnesium compound, and an ammonium compound, the carboxyl and/or hvdroxv-containing water-soluble macromolecular organic matter and the hydrophobic macromolecular organic matter having the periodic geometric structure generates an organic-inorganic interface matching synergistic effect to control a nucleation speed, a quantity, a nucleate site, and a crystal form orientation of complex arsenate crystallization, the periodic geometric structure and a structure of the complex arsenate crystals are matched, and the complex arsenate crystals are induced to precisely nucleate on surfaces;”
should be
“2) sequentially adding a mixed ammonium magnesium reagent and a hydrophobic macromolecular organic matter having a periodic geometric structure into the arsenic-containing alkaline leaching solution, and taking a reaction under a stirring to obtain complex arsenate crystals cladded with an organic matter,
wherein the mixed ammonium magnesium reagent is comprised of a carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter, a magnesium compound, and an ammonium compound,
wherein the carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter and the hydrophobic macromolecular organic matter having the periodic geometric structure generates an organic-inorganic interface matching synergistic effect to control a nucleation speed, a quantity, a nucleate site, and a crystal form orientation of complex arsenate crystallization,
wherein the periodic geometric structure and a structure of the complex arsenate crystals are matched, and
wherein the complex arsenate crystals are induced to precisely nucleate on surfaces;”
Appropriate correction is required.
Claim Rejections - 35 USC § 103
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 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.
Claims 1-8 and 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over Gu (previously cited, “Arsenic removal from lead-zinc smelter ash by NaOH-H2O2 leaching”) in view of:
Tian (previously cited, “Alkali circulating leaching of arsenic from copper smelter dust based on arsenic-alkali efficient separation”),
Liu080 (previously cited, CN 111013080 A, English Machine Translation provided),
Zhang328 (cited by Applicant in IDS filed April 12, 2023, CN 113929328 A, English Machine Translation provided),
Wang (previously cited, CN 109847256 B, English Machine Translation provided),
Chen (previously cited, “Thermal decomposition of magnesium ammonium phosphate and adsorption properties of its pyrolysis products toward ammonia nitrogen”),
Stefov (previously cited, “Infrared and Raman spectra of magnesium ammonium phosphate hexahydrate (struvite) and its isomorphous analogues. V. Spectra of protiated and partially deuterated magnesium ammonium arsenate hexahydrate (arsenstruvite)”) and
Liu678 (previously cited, CN 106636678 A, English Machine Translation provided).
Regarding Claim 1, Gu discloses a method for removing arsenic from arsenic-containing solid waste through a short reflow process (Abstract), comprising:
a step 1) of performing oxidative alkaline leaching on lead-zinc smelter ash (Abstract; 2.1, Materials; NaOH (alkaline leaching medium) and H2O2 (oxidant) reads on oxidative alkaline leaching; lead-zinc smelter ash reads on the claimed nonferrous metallurgy arsenic-containing solid waste).
Gu discloses forming arsenate ions in the alkaline leaching solution, wherein the arsenic has been separated from the ash by the leaching (Abstract; Sect. 3.6), but fails to disclose a further step 2) of separating the arsenic from the alkaline leaching solution by forming complex arsenate crystals.
Tian teaches a method of selectively removing arsenic from an alkaline leaching solution by forming MgNH4AsO4-6H20 salt precipitate, allowing for the reuse of alkaline water while reducing costs associated with arsenic slag/waste in landfills (Pg. 2, Col. 1, para. 3-Col. 2, para. 2). One of ordinary skill in the art would appreciate the salt precipitate MgNH4AsO4-6H20 reads on the claimed ‘complex arsenate crystals’.
Tian teaches wherein a mixed reagent of MgSO4-7H2O (magnesium compound) and (NH4)2SO4 (ammonium compound) is sequentially applied to the arsenic-containing alkaline leaching solution after formation and stirred in order to separate the arsenic from the alkali solution by precipitating MgNH4AsO4-6H20 salt (Pg. 2, Sect. 2.2.2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used and sequentially added the magnesium ammonium mixed reagent of Tian, for the invention disclosed by Gu, in order to selectively remove the arsenic from the alkaline leaching solution by forming MgNH4AsO4-6H20 salt precipitate, and thereby allowing for the reuse of alkaline water while reducing costs associated with arsenic slag/waste in landfills (see teaching by Tian above),
Tian fails to disclose wherein the mixed ammonium magnesium reagent further comprises a carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter.
Liu080 teaches adding an organic flocculating agent of sodium polyacrylate during the precipitation of arsenate complexes (calcium arsenate), in order to increase the volume of solid particles, shorten settle times, and improve the efficiency of filtering slag water separation (para. [0060], “calcium arsenate…precipitate under the action of flocculant”).
Zhang328 teaches a wet solution reaction process of removing gypsum from slag, wherein gypsum sulphate complex (calcium sulphate) is formed by crystallization, and wherein a growth inducing agent is added for the precipitation reaction in order to control the nucleation and therefore grain diameter and shape of the sulphate crystal (gypsum complex) (para. [0010]; para. [0018]-[0019]). Zhang328 teaches wherein the growth inducing agent is one of sodium polyacrylate, polyethylene glycol, polyvinyl alcohol, or combinations thereof (para. [0013]; para. [0039], polyethylene glycol and sodium polyacrylate are used in combination; para. [0044], polyethylene glycol and polyvinyl alcohol are used in combination).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included sodium polyacrylate in the ammonium magnesium mixed reagent of Tian, as taught by Liu080 and Zhang328, or further one of sodium polyacrylate, polyethylene glycol, or polyvinyl alcohol and combinations thereof, as taught by Zhang328, for the invention disclosed by Gu and Tian. One would be motivated to do this in order to control the nucleation and therefore grain diameter and shape of the precipitated crystal (see teaching above by Zhang328), and further to increase the volume of precipitated solid particles, thereby shortening settle times and improving the efficiency of filtering slag water separation (see teaching by Liu308 above). One of ordinary skill in the art would appreciate that sodium polyacrylate and polyethylene glycol read on the claimed carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter.
While Zhang328 is directed to nucleating crystals from a gypsum complex, one of ordinary skill in the art would appreciate the applicability for using the growth inducing agent for other wet chemical systems and processes which involve the formation and crystallization of complexes for component removal from slag, including processes directed to arsenate complex nucleation and removal thereof from slag, as taught and demonstrated by Liu080 (see above wherein Liu080 also introduces the same chemical species (sodium polyacrylate) to a reagent for arsenate precipitation - para. [0011]).
Tian fails to disclose wherein a hydrophobic macromolecular organic matter having a periodic geometric structure is added to the mixed ammonium magnesium reagent.
Zhang328 teaches wherein polyvinyl alcohol may be combined with one of sodium polyacrylate and polyethylene glycol (para. [0013]; [0044]).
Wang further teaches forming a polymer layer, preferably of polyvinyl alcohol (PVA), on a precipitate of arsenate by introduction to the arsenic containing solution, wherein the polymer layer protects the secondary dissolution of the arsenate complex, leading to lower leaching toxicity and higher stability (para. [0012]; para. [0018]-[0019]; para. [0022]-[0024]; para. [0038]). One of ordinary skill in the art would appreciate that forming a layer of PVA on the surface of the arsenate precipitate reads on obtaining a complex arsenate crystal cladded with organic matter, as claimed. One of ordinary skill in the art would appreciate that PVA reads on a hydrophobic macromolecular organic matter having a periodic geometric structure as claimed (see also instant Claim 8 wherein the hydrophobic macromolecular organic matter having a periodic geometric structure is polyvinyl alcohol).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have introduced PVA, and therefore a hydrophobic macromolecular organic matter having a periodic geometric structure as claimed, to the arsenic containing solution, as taught by Zhang328 and Wang, thereby coating (cladding) the complex arsenate crystal with organic matter, as taught by Wang, for the invention disclosed by Gu, Tian, Liu080 and Zhang328, in order to prevent secondary dissolution of the arsenate complex, reduce leaching toxicity and to improve stability (see teachings above).
Thus, Liu080, Zhang328 and Wang disclose wherein the carboxyl and/or hvdroxv-containing water-soluble macromolecular organic matter (sodium polyacrylate and/or polyethylene glycol) and the hydrophobic macromolecular organic matter having the periodic geometric structure (polyvinyl alcohol) generates an organic-inorganic interface matching synergistic effect to control a nucleation speed, a quantity, a nucleate site, and a crystal form orientation of complex arsenate crystallization, wherein the complex arsenate crystals are induced to precisely nucleate on surface, as claimed (see teachings above and by Zhang328 wherein nucleation and quantity parameters are controlled by PAAS, PEG and PVA, which reads on the claimed limitations).
Further, Gu in view of Tian, Liu080, Zhang328 and Wang disclose the same reactive components as the instant invention (ammonium sulfate and magnesium sulfate mixture - see Tian; sodium polyacrylate or polyethylene glycol addition to mixed reagent – see Liu080 and Zhang328; inclusion of polyvinyl alcohol – see Wang (see also Zhang328); instant specification PG pub - para. [0016]-[0017] and para. [0045], magnesium sulfate and ammonium sulfate; para. [0015], sodium polyacrylate and/or polyethylene glycol; para. [0020], polyvinyl alcohol).
Because the process and the reaction components of Gu, Tian, Liu080, Zhang328 and Wang are the same as the instant invention, one of ordinary skill in the art would appreciate that the periodic geometric structure and a structure of the complex arsenate crystals are matched, as claimed, and that the reactive components behave as claimed (organic-inorganic interface matching synergistic effect and precise nucleation, see above).
When the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). See MPEP 2112.01.
Tian fails to disclose a further step 3) of roasting and of reduction roasting the ammonium magnesium precipitate, and recycling high-purity metallic arsenic.
Chen teaches removing ammonia and water concomitantly from MgNH4PO4-6H20, a structurally similar precipitate to MgNH4AsO4-6H20 (see Abstract of Tian; see also Stefov, Introduction, wherein magnesium ammonium arsenate is isostructural with magnesium ammonium phosphate), by heating and thermal decomposition (roasting) in order to recover ammonia and pyrolysis products such as magnesium phosphate (Abstract; Pg. 498, Col. 1, Para. 3; equations 8).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have applied the roasting technique of Chen to roast the MgNH4AsO4-6H20 of Tian, thereby thermally decomposing the manganese ammonium arsenate, in order to form magnesium arsenate and recover and recycle the ammonia (see teaching by Chen above).
Liu678 teaches reduction roasting by mixing an arsenate of magnesium with 15% carbon powder, performing reduction roasting for 2-4 hours at a temperature of 700-1200C, making arsenic steam (smoke) and condensing in order to produce high purity elemental arsenic (para. [0011]-[0016]; para. [0033]-[0037]; see para. [0037] 15% carbon powder by weight of raw material). Liu678 teaches that this is a preferable form to arsenate, which is toxic and chemically unstable, and the reduction roasting renders the arsenic waste harmless and recycles it as a resource (para. [0004]; para. [0008]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have further roasted the magnesium arsenate by performing reduction roasting, including mixing the magnesium arsenate with carbon, and making arsenic steam (smoke) and condensing to form high purity elemental arsenic, as taught by Liu678, for the invention disclosed by Tian and Chen. One would be motivated to do this in order to form high purity arsenic in place of the toxic and chemically unstable arsenate, thereby rendering the arsenic waste harmless and recycling it as a resource (see teaching by Liu above). One of ordinary skill in the art would appreciate that while Gu teaches away from direct roasting of the raw material waste (dust/untreated smelter ash), Gu does not teach away from roasting operations after the separation of the arsenic from the waste and of the alkaline leaching products.
Regarding Claim 2, Gu and Tian discloses wherein the nonferrous metallurgy arsenic-containing solid waste comprises at least one of a copper smelting dust (Gu, Introduction, para. 1, smelting process of copper, lead and zinc which produces smelter ash; Tian, Abstract; copper smelter dust).
Regarding Claim 3, Gu discloses grinding the smelter ash (nonferrous metallurgy arsenic-containing solid waste) to a size of below 74um, performing oxidative alkaline leaching with NaOH and H2O2, using a 10:1 liquid (ml) to solid (g) ratio, 3 mol/L of NaOH (alkaline leaching medium), a leaching time of 2h, and a leaching temperature of 75C (Abstract; 2.1, Materials).
Gu discloses stirring, but does not disclose the stirring speed.
Tian teaches forming an arsenic containing alkaline leaching solution using a stirring speed of 600rpm (Sect. 2.2.1, 600 r/min).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used a stirring speed of 600rpm, as taught by Tian, for the invention disclosed by Gu, because Tian demonstrates that this is an sufficient speed for alkaline leaching of arsenic containing waste. It has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. See MPEP 2144.05.I-II.A).
Gu and Tian therefore disclose the limitations requiring oxidative leaching performed with hydrogen peroxide as an oxidizing agent, sodium hydroxide as an alkaline leaching medium, a leaching temperature of 50-90C (75C), a stirring speed of 200-700 rpm (600rpm), a leaching time of 1-3 hours (2 hours), a particle size of the arsenic-containing solid waste ground to 1mm or less (less than 74um), a concentration of alkaline leaching medium of 0-4mol/L (3mol/l), and a liquid (ml) to solid (g) ratio of 4-10 (ratio of 10).
In the case where the claimed ranges “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). See MPEP § 2144.05.I.
Regarding Claim 4, Tian discloses wherein the mixed ammonium magnesium reagent comprises a preferred (Mg2+):As molar ratio of 1.5:1 and a (NH4+):As molar ratio of ranging from 3:1 to 6:1 to balance NH4+ consumption (section. 3.3, Table 4), with 8:1 molar ratio being most preferred for securing precipitation of . MgNH4AsO4-6H20 (Pg. 9, Col. 1, Para. 1-2). Therefore, Tian discloses a mole ratio of the magnesium compound to the ammonium compound n(Mg/N) range from 1.5:3 to 1.5:8, or 0.1875-0.5, which reads on the claimed range of 0.2-1.
Additionally, Tian teaches wherein the molar ratios are a result effective variable, the result being the precipitation of MgNH4AsO4-6H20 instead of Mg(OH)2, and the consumption of NH4+ (see Pg. 9, Col. 1, Para. 1-2 and section 3.3). Therefore, it would have been obvious to have used a reagent ratio of Mg/N within the claimed range in order to successfully precipitate the desired precipitate, ammonium magnesium arsenate salt (MgNH4AsO4-6H20), rather than Mg(OH)2, while balancing the consumption of NH4+, as taught by Tian (see teaching above).
In the case where the claimed ranges “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). See MPEP § 2144.05.I.
Liu080 further discloses wherein the sodium acrylate (carboxyl and/or hydroxy-containing water-soluble macromolecular matter) is included in an amount of 0.001-0.05% by mass of the liquid in the system.
One of ordinary skill in the art would appreciate that the leachant of Gu (3mol/l of NaOH and 2.4% H2O2) would comprise a density of about 1.128g/ml, and therefore the invention of Tian in view of Gu would comprise an amount of sodium acrylate of 9.7-487mg/L.
Tian discloses wherein the filtrate comprises 9116mg/L (9.116g/l) of arsenic (Pg. 5, Col. 2, Para. 1), such that one of ordinary skill in the art would appreciate that Tian uses approximately 24-64g/L of ammonium compound and 22g/L of magnesium compound in order to achieve the desired NH4+:As and Mg2+:As molar ratios of 3-8:1 and 1.5:1, respectively (values calculated using the molar masses of arsenic, magnesium sulfate and ammonium sulfate).
One of ordinary skill in the art would therefore appreciate that the invention of Gu, Tian and Lu therefore discloses an amount of sodium acrylate (9.7-487mg/L) to total amount of ammonium compound and magnesium compound (46-86g/L) of 0.11-10.6 mg/g, and within the claimed range of 1-10mg/g. For example, a reagent system with 100mg/L of sodium acrylate and molar ratios of NH4+:As and Mg2+:As of 6:1 and 1.5:1, respectively, would comprise 70g/L total of ammonium and magnesium compound and a value of sodium acrylate to ammonium and magnesium compound of 1.4mg/g.
In the case where the claimed ranges “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). See MPEP § 2144.05.I.
Regarding Claim 5 and Claim 11, Liu308 teaches wherein the carboxyl and/or hydroxy-containing water-soluble macromolecular matter is sodium polyacrylate (para. [0060]; see Claim 1 above).
Regarding Claim 6, Tian discloses wherein the magnesium compound is at least one of magnesium sulfate and the ammonium compound is at least one of ammonium sulfate (Sect. 2.2.2).
Regarding Claim 7, Tian discloses wherein the mole ratio of magnesium to arsenic (Mg/As) is 1.5, which reads on the claimed range of 1.2-2.5 (Abstract).
Tian discloses wherein the amount of arsenic available in filtrate (leachant solution) is 9.116g/l (Pg. 5, Col. 2, Para. 1).
Wang further discloses wherein the polyvinyl alcohol is 1-10% the mass of the precipitate (MgNH4AsO4-6H20). An amount of 9.116g/L of As would equate to 29.3g/L precipitate for 96.38% reaction rate of the arsenic to MgNH4AsO4-6H20 (arsenic accounts for about 30% of the weight of the precipitate; see Tian, conclusions wherein 96.38% of arsenic is removed from the alkaline solution through precipitation), and one of ordinary skill in the art would therefore appreciate including 0.293-2.93g/L polyvinyl alcohol, which reads on the claimed range of 1-5g/L.
In the case where the claimed ranges “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). See MPEP § 2144.05.I.
Regarding Claim 8 and Claim 12, Wang discloses wherein the hydrophobic macromolecular organic matter having the periodic geometric structure is polyvinyl alcohol (para. [0038]).
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Gu (previously cited, “Arsenic removal from lead-zinc smelter ash by NaOH-H2O2 leaching”) in view of Tian (previously cited, “Alkali circulating leaching of arsenic from copper smelter dust based on arsenic-alkali efficient separation”), Liu080 (previously cited, CN 111013080 A, English Machine Translation provided), Zhang328 (cited by Applicant in IDS filed April 12, 2023, CN 113929328 A, English Machine Translation provided), Wang (previously cited, CN 109847256 B, English Machine Translation provided), Chen (previously cited, “Thermal decomposition of magnesium ammonium phosphate and adsorption properties of its pyrolysis products toward ammonia nitrogen”), Stefov (previously cited, “Infrared and Raman spectra of magnesium ammonium phosphate hexahydrate (struvite) and its isomorphous analogues. V. Spectra of protiated and partially deuterated magnesium ammonium arsenate hexahydrate (arsenstruvite)”) and Liu678 (previously cited, CN 106636678 A, English Machine Translation provided), as applied to Claim 1 above, in further view of:
Zhang2020 (previously cited, “Arsenic removal from arsenic-containing copper and cobalt slag using alkaline leaching technology and MgNH4AsO4 precipitation”) and
Han (previously cited, CN 111876601 A, English Machine translation provided).
Regarding Claim 9, Tian teaches forming an arsenic containing alkaline leaching solution using a stirring speed of 600rpm (Sect. 2.2.1, 600 r/min), but fails to disclose the claimed reaction parameters, including a temperature of 30-50C, a stirring speed of 300-500rpm, and a reaction time of 1-3 hours.
Zhang2020 teaches a magnesium ammonium reaction with alkaline leachant solution which precipitates MgNH4AsO4-6H2O, wherein precipitation was optimized for a temperature of 30C, and wherein reaction rates were similar for 0.5-2 hours (section. 3.3.3; Fig. 12-13).
Han similarly teaches a magnesium ammonium reaction with alkaline leachant solution which precipitates MgNH4AsO4, wherein the precipitation reaction proceeds using a stir speed of 300-400rpm, a reaction time of 0.8-1.5 hours (50-90 minutes) (para. [0012]; para. [0019]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used a temperature of 30C, as taught by Zhang2020, a stirring speed of 300-400rpm, as taught by Han, and a reaction time of up to 1.5 hours, as taught by Zhang2020 and Han, for the invention disclosed by Gu and Tian, in order to maximize the completion of the precipitation reaction, and because Zhang and Han demonstrates that these parameters are sufficient for a precipitation reaction which forms MgNH4AsO4 using a mixed magnesium ammonium reagent and an oxidative alkaline leaching solution. It has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. See MPEP 2144.05.I-II.A).
Gu and Tian therefore disclose the limitations requiring oxidative leaching performed with hydrogen peroxide as an oxidizing agent, sodium hydroxide as an alkaline leaching medium, a leaching temperature of 50-90C (75C), a stirring speed of 200-700 rpm (600rpm), a leaching time of 1-3 hours (2 hours), a particle size of the arsenic-containing solid waste ground to 1mm or less (less than 74um), a concentration of alkaline leaching medium of 0-4mol/L (3mol/l), and a liquid (ml) to solid (g) ratio of 4-10 (ratio of 10).
In the case where the claimed ranges “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). See MPEP § 2144.05.I.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Gu (previously cited, “Arsenic removal from lead-zinc smelter ash by NaOH-H2O2 leaching”) in view of Tian (previously cited, “Alkali circulating leaching of arsenic from copper smelter dust based on arsenic-alkali efficient separation”), Liu080 (previously cited, CN 111013080 A, English Machine Translation provided), Zhang328 (cited by Applicant in IDS filed April 12, 2023, CN 113929328 A, English Machine Translation provided), Wang (previously cited, CN 109847256 B, English Machine Translation provided), Chen (previously cited, “Thermal decomposition of magnesium ammonium phosphate and adsorption properties of its pyrolysis products toward ammonia nitrogen”), Stefov (previously cited, “Infrared and Raman spectra of magnesium ammonium phosphate hexahydrate (struvite) and its isomorphous analogues. V. Spectra of protiated and partially deuterated magnesium ammonium arsenate hexahydrate (arsenstruvite)”) and Liu678 (previously cited, CN 106636678 A, English Machine Translation provided), as applied to Claim 1 above, in further view of:
Mac (previously cited, “Magnesium Arsenates”).
Regarding Claim 10, Chen discloses a roasting time of 2 hours (120 minutes), which reads on the claimed range of 2-3 hours. However, Chen discloses roasting temperatures (100C) which are optimized for magnesium ammonium phosphate (Sect. 2.2), and does not disclose optimal temperatures for magnesium ammonium arsenate.
Mac teaches wherein MgNH4AsO4-6H20 loses water and ammonia when heated from 40-235C (Para. 3). One of ordinary skill in the art would appreciate the heating taught by Mac to be equivalent to the roasting of Chen because the heating removes water and ammonia components.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used a roasting temperature up to 235C, as taught by Mac, for the invention disclosed by Gu, Tian and Chen, in order to completely remove the water and ammonia from the precipitate of ammonium magnesium arsenate, thereby recycling the ammonia (see teaching above; see teaching to roast by Chen in Claim 1 in order to recycle ammonia).
Liu678 further discloses wherein the reduction roasting is performed in an inert atmosphere, at a roasting temperature of 700-1200C, which reads on the claimed range of 800-1200C, at a time of 2-4 hours, and a dosage of carbon powder of 15% the mass of the roasted slag (para. [0014]-[0015]; para. [0033], carbon was 15% raw material weight).
Response to Arguments
Applicant’s arguments, filed November 26, 2025, with respect to Claim 1, and dependent claims thereof, rejected under 35 U.S.C. 103 over Gu in view of Tian, Liu080, Wang, Chen, Stefov and Liu678, have been fully considered and are persuasive in view of Applicant’s amendments to the claims further limiting the structure of the reactants and functions thereof. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made over Gu in view of Tian, Liu080, Zhang328, Wang, Chen, Stefov and Liu678, as detailed above.
Regarding Liu080:
Applicant argues that the flocculant agent of Liu080 functions differently than the claimed invention.
Applicant argues that the sodium polyacrylate is to reduce the content of P, F and arsenic, and argues that the sodium polyacrylate of Liu080 accumulates already precipitated arsenate crystals acting as a binding agent, while the sodium polyacrylate of the instant invention functions to control growth of arsenate crystals through electrostatic interactions during precipitation (Remarks, Pg. 5-7).
Applicant argues that Liu080 is designed for sulfide-based arsenic precipitation while the instant method uses an ammonium magnesium arsenate precipitation system (Remarks, Pg. 7-8).
These arguments are not found persuasive.
One of ordinary skill in the art would appreciate the applicability of adding sodium polyacrylate to the system of Gu and Tian because the sodium polyacrylate is added during precipitation of an arsenate complex (see Liu080, para. [0060]), and an arsenate precipitation reaction is also used by Tian. Further, one of ordinary skill in the art would appreciate that the sodium polyacrylate would behave the same as the instant invention (electrostatic interactions during precipitation) because the substance is the same as the instant invention and would be applied during precipitation (para. [0060], wherein calcium arsenate is precipitated under the action of the flocculant).
In response to applicant's argument that Liu080 does not teach nucleation control during precipitation and electrostatic interactions, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985). Further, while Applicant argues the arsenate complex is already precipitated prior to flocculant addition, Liu080 clearly states that precipitate occurs under the action of flocculent, i.e., flocculent is present during precipitation and added prior to reaction).
Additionally, in response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., electrostatic interaction of Mg2+ ions) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
While Liu080 discloses two precipitation reactions, the teaching relied upon is the second precipitation reaction which involves forming an arsenate complex. The first precipitation regarding arsenic sulfide reactions is not relied upon.
Applicant argues that Liu080 is silent towards a hydrophobic macromolecular organic matter having a periodic geometric structure and does not disclose sequentially adding ammonium magnesium reagent (Remarks, Pg. 8-9).
This argument is not found persuasive.
Liu080 is not relied upon to teach these features. Tian teaches sequentially adding ammonium magnesium reagent and Wang teaches the claimed hydrophobic macromolecular organic matter having a periodic geometric structure, while Liu080, in addition to Zhang328 (see above), teach adding sodium polyacrylate to the ammonium magnesium reagent taught by Tian. In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
Regarding Wang:
Applicant argues that Wang is directed to a ferric arsenate (Remarks, Pg. 10-11).
Applicant argues that Wang does not disclose a carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter, or sequentially adding a mixed ammonium magnesium reagent (Remarks, Pg. 10, Pg. 12).
Applicant argues that Wang does not teach that PVA participates in the crystallization regulation process, and does not produce the newly amended claimed effects regarding synergistic effects and organic-inorganic interface matching, and the combination of Tian, Liu080 and Wang do not disclose the claimed effects either (Remarks, Pg. 11, 13-15).
These arguments are not found persuasive.
One of ordinary skill in the art would appreciate the applicability of adding PVA to the system of Gu and Tian because Tian also teaches precipitations of an arsenate complex similarly to Wang.
Regarding teachings for other features, Wang is not relied upon to teach a carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter and sequentially adding a mixed ammonium magnesium reagent. Tian teaches sequentially adding ammonium magnesium reagent and Liu080, in addition to Zhang328 (see above), teach adding sodium polyacrylate (a carboxyl and/or hydroxy-containing water-soluble macromolecular organic matter) to the ammonium magnesium reagent taught by Tian, while Wang (and Zhang328, see above) teach the claimed hydrophobic macromolecular organic matter having a periodic geometric structure. In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
In response to applicant's argument that Wang does not teach synergistic effects of nucleation control during precipitation and electrostatic interactions, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
Additionally, in response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., electrostatic interaction of Mg2+ ions) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Further, as stated in the rejection above, Gu, Tian, Liu080, Zhang328 and Wang disclose the claimed reaction and disclose the instant invention reaction components present during precipitation, and one of ordinary skill in the art would appreciate the reaction components (magnesium sulfate, ammonium sulfate, sodium polyacrylate and/or polyethylene glycol, and PVA) to behave in the same manner as the instant invention.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Dambies (“Treatment of arsenic-containing solutions using chitosan derivatives: uptake mechanism and sorption performances”): teaches wherein chitosan improves arsenic removal efficiency, wherein the arsenic has complexed with a struvite type structure (molybdate) from solution (Abstract; Conclusions).
Zhang2020 (applied above, further teachings, “Arsenic removal from arsenic-containing copper and cobalt slag using alkaline leaching technology and MgNH4AsO4 precipitation”): teaches forming an arsenic-containing alkaline leaching solution by applying H2O2 oxidant and NaOH to copper slag comprising a size of 12.58um, and further using magnesium sulfate and ammonium carbonate compounds as a means to form complex arsenate crystals of MgNH4AsO4-6H20 for the removal of the arsenic from the slag (Abstract; section 2.2.1).
Tian2 (“Comprehensive utilization and safe disposal of hazardous arsenic alkali slag by the combination of beneficiation and metallurgy”): teaches wherein the magnesium salt to form the precipitate may be one of magnesium sulfate, magnesium carbonate and magnesium chloride, while the ammonium salt may be one of ammonium carbonate, ammonium sulfate and ammonium chloride (Pg. 3, Col. 1, para. 3).
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.
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CATHERINE P. SMITH
Patent Examiner
Art Unit 1735
/CATHERINE P SMITH/ Examiner, Art Unit 1735
/KEITH WALKER/Supervisory Patent Examiner, Art Unit 1735