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 .
Claim Status
The Amendment filed on 22 January 2026 has been entered; claims 1-5 and 8-19 remain pending.
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 22 February 2026 has been entered.
Response to Arguments
Applicant’s arguments, see Pages 5-8 of the Remarks, filed 22 January 2026, with respect to the rejections of claims 1-5, 10, and 11 under 35 USC 103 over Li in view of Iwata or Li in view of Coillet and Iwata have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new grounds of rejection for independent claims 1 and 12 are made under 35 USC 103 over Li in view of Frohner or Li in view of Coillet and Frohner, as discussed below in detail. Briefly, Frohner is applied to provide a teaching and motivation for a precipitate outlet that reversibly opens and closes, wherein barium sulfate is removed from the precipitate outlet upon gravity-based collection of barium sulfate precipitate as now required by claims 1 and 12.
Regarding Applicant’s arguments pertaining to dependent claims 5, 8, and 9, as well as claims 12-15 and 18-20 which were rejected under 35 USC 103 over Li in view of Coillet and Iwata and claims 16 and 17 which were rejected under 35 USC 103 over Li in view of Coillet, Iwata, and further in view of Colelli, it is submitted that all substantive arguments made therein were addressed above.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-5, 10, and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al. (U.S. Patent Publication # 2019/0225867) in view of Frohner et al. (U.S. Patent # 3974039), OR Li et al. (U.S. Patent Publication # 2019/0225867) in view of Coillet et al. (U.S. Patent # 4392959) and Frohner et al. (U.S. Patent # 3974039), hereinafter “Li”, “Frohner”, and “Coillet”.
With respect to claim 1, Li teaches a method of producing barium sulfate (see Paragraph [0028]) with seawater treatment system 100 (see Fig. 1; Paragraph [0027, 0028], considered to meet both “a barium sulfate production system” and an “agitation unit” since system 100 comprises a mixer), the method comprising: introducing an amount of seawater 102 comprising sulfate (“a sulfate contaminated water”) (Paragraph [0027]) to a mixer of seawater treatment system 100 (“the barium sulfate production system”; “agitation unit”) via an aqueous fluid feed line (see leftmost arrow feed for seawater 102) in fluid connection with the seawater treatment system 100 (“barium sulfate production system” and “agitation unit”) (Paragraph [0030]), wherein the agitation unit seawater treatment system 100 (“barium sulfate production system” and “agitation unit”) comprises a treated fluid outlet line 57 and a bottom precipitate outlet 108; introducing an amount of a barium source 104 to the seawater treatment system 100 (“barium sulfate production system” and “agitation unit”) (Paragraph [0028, 0030]), thereby forming a treatment mixture comprising the sulfate contaminated water and barium chloride; and agitating the treatment mixture in a mixer with agitator to promote ion association between barium cations from the barium source and sulfate anions, thereby producing a barium sulfate precipitate 108 and a treated water 57, which is removed from seawater treatment system of Li through the right outlet (“treated water outlet”) (Paragraphs [0028-0030, 0032]).
Regarding the limitations “a mixing device positioned on an inner surface of the agitation unit”, it is submitted that the agitator/mixer disclosed by Li would have to be associated/mounted on an inner surface of the agitator, for if it wasn’t, the flow of seawater through seawater treatment device 100 would cause an unattached agitator or mixer to simply settle at the bottom or push up against the side of treatment device 100, depending on flow patterns (which would in any case meet the limitations “positioned on an inner surface”).
In the event that the Examiner is incorrect interpreting the seawater treatment system 100 of Li as both a “barium sulfate production system” and “an agitation unit”, the rejection is continued below in view of Coillet.
Li does not specifically teach that the agitation unit/mixer comprises the treated fluid outlet line and precipitate outlet (Li teaches a mixer and settling vessel/tank in Paragraph [0030], wherein the settling vessel would have the precipitate outlet and treated fluid outlet line and be positioned after the mixer).
Coillet teaches a clarifier 17 which comprises a stirrer (“agitation unit”) which also comprises a supernatant outlet (“treated fluid outlet line”) and settled product slurry stream precipitate outlet from which barium sulfate precipitate is removed (Column 13, lines 27-61).
It would have been obvious to modify the mixer and settling vessel combination of Li for the formation and removal of barium sulfate with the clarifier of Coillet because Li teaches that the seawater treatment system 100 can comprise a clarifier, and Coillet teaches that seawater (Column 5, line 4-7) is treated in clarifier 17 by addition of a soluble barium ion source to form a barium sulfate precipitate with residual sulfate levels as low as 15 ppm in the treated supernatant (Column 13, lines 52-61). The foregoing modification results in clarifier that is an agitation unit that comprises precipitate outlet and treated fluid outlet as claimed.
Regarding the limitations “a mixing device positioned on an inner surface of the agitation unit”, it is submitted that the stirrer disclosed by Coillet would have to be associated/mounted on an inner surface of the clarifier, for if it wasn’t, the stirrer would simply settle on the bottom of the clarifier and would not be able to turn.
Neither Li nor Li in view of Coillet specifically teach that the precipitate outlet reversibly opens and closes.
Frohner teaches sludge valve V provided at the bottom of a settling region in which sludge comprising barium sulfate is discharged intermittently or continuously (see Fig. 2; Column 5, lines 1-21, 34-37), meeting the limitations “reversibly opening and closing” a precipitation outlet.
It would have been obvious to one of ordinary skill in the art to add the sludge valve of Frohner to the precipitation outlet of Li or Li/Coillet because Frohner teaches that the sludge valve(s) allow for continuous or intermittent discharge of sludge comprising barium sulfate in response to the settling rate of the barium sulfate, such that if the settling level is high, the valve is in an open state, allowing for barium sulfate containing sludge discharge to be optimized as the sludge builds up (see Column 5, lines 10-21). The ordinary artisan would have recognized that having sludge valve(s) would provide the advantage of controlling sludge discharge within the treatment unit generating precipitate so as to not overload the seawater treatment device of Li, which receives seawater 102 for treatment for separation of salts, just as the system/method of Frohner (see Abstract; Fig. 2).
With respect to claim 2, Li in view of Frohner or Li in view of Coillet and Frohner teaches that the sulfate contaminated water is seawater (see Li: Paragraph [0027], see Coillet: Column 5, lines 4-7, and see Abstract; Fig. 2 of Frohner).
With respect to claims 3 and 4, Li in view of Frohner or Li in view of Coillet and Frohner teaches that the treated seawater 57 comprises less than 100 mg/L/ppm sulfate (see Li: Paragraph [0029], and see Coillet: Column 13, lines 52-61) and that treated seawater is removed via outlet line 57 (see Li: Fig. 1; Paragraphs [0027, 0029], and see supernatant of Coillet from clarifier 17 in Column 13, lines 60-62).
With respect to claim 5, Li in view of Frohner or Li in view of Coillet and Frohner teaches or renders obvious the limitations of claim 1, including all active steps and also teach that the sulfate contaminated water is seawater, and further that the treated fluid is used as fracturing fluid as consistent with claim 11. In view of the foregoing, the Examiner submits that the recited purity of barium sulfate is met as an inherent result by carrying out the method according to Li in view of Frohner or Li in view of Coillet and Frohner. The mere observation of still another beneficial result of an old process cannot form the basis of patentability. Allen et al. v. Coe, 57 USPQ 136; In re Maeder et al. 143 USPQ 249.
With respect to claim 10, Li in view of Frohner or Li in view of Coillet and Frohner teaches that the sulfate contaminated seawater has a sulfate concentration of at least 3000 or at least 4000 mg/L (see Li: Paragraph [0027], and see Table 1 of Li which lists the components of untreated seawater, with sulfate at 4,132 mg/L (see Li: Paragraph [0043]; Table 1), meeting the limitations “prior to forming the treatment mixture, determining a concentration of sulfates of the sulfate contaminated water”.
With respect to claim 11, Li in view of Frohner or Li in view of Coillet and Frohner teaches combining treated seawater 57 with one or more chemical additives 81 to form a fracture fluid 58 (“an injection fluid”) for use in oil and gas applications (see Li: Paragraphs [0020-0027]), especially [0021] and [0027]).
Claim 5 is rejected under 35 U.S.C. 103 as obvious over Li et al. (U.S. Patent Publication # 2019/0225867) in view of Frohner et al. (U.S. Patent # 3974039), OR Li et al. (U.S. Patent Publication # 2019/0225867) in view of Coillet et al. (U.S. Patent # 4392959) and Frohner et al. (U.S. Patent # 3974039) as applied to claim 1, and further in view of Hou et al. (“Sulfate Ion Removal from Seawater for Hydraulic Fracturing by Barium Sulfate Precipitation”, published online on 07 March 2023, Abstract, Page 1, accessed on 20 May 2025 at https://onepetro.org/SPEMEOS/proceedings-abstract/23MEOS/2-23MEOS/517228), hereinafter “Li”, “Frohner”, “Coillet”, and “Hou”.
Assuming for the sake of compact prosecution that the Examiner’s analysis regarding the purity of precipitated BaSO4 obtained by the process of Li in view of Frohner or Li in view of Coillet and Frohner is incorrect, the rejection is alternative rejected further in view of Hou.
With respect to claim 5, Li in view of Frohner or Li in view of Coillet and Frohner does not specifically teach that the barium sulfate precipitate has less than 10 wt% impurities, based on the total weight of the barium sulfate precipitate, as determined by powder X-ray diffraction.
Hou teaches barium sulfate precipitated from seawater having a purity of greater than 90% as confirmed by XRD (Abstract).
It would have been obvious to one of ordinary skill in the art at the time the invention was effectively filed that the process of Li in view of Frohner or Li in view Coillet and Frohner could yield a barium sulfate precipitate purity of greater than 90% as taught by Hou because the processes both used seawater as the sulfate source and barium chloride as the barium source in the same or similar process for precipitation of barium sulfate (see Paragraphs [0028-0030] of Li, Column 13, lines 27-61 of Coillet, and Abstract of Hou). Since the process is the same or similar using the same sulfate and barium source, the ordinary artisan would expect the purity of barium sulfate precipitate to be the same or similar value.
Claims 8 and 9 are rejected under 35 U.S.C. 103 as obvious over Li et al. (U.S. Patent Publication # 2019/0225867) in view of Frohner et al. (U.S. Patent # 3974039), OR Li et al. (U.S. Patent Publication # 2019/0225867) in view of Coillet et al. (U.S. Patent # 4392959) and Frohner et al. (U.S. Patent # 3974039) as applied to claim 1, and further in view of Amirzadeh-Asl et al. (U.S. Patent Publication # 2005/0180912), hereinafter “Li”, “Frohner”, “Coillet”, and “Amirzadeh-Asl”.
With respect to claims 8 and 9, Li in view of Frohner or Li in view of Coillet and Frohner do not specifically teach washing or drying as claimed.
Amirzadeh-Asl teaches washing and drying precipitated barium sulfate (Abstract; Paragraph [0001]).
It would have been obvious to one of ordinary skill in the art at the time the invention was effectively filed to wash and dry the barium sulfate precipitate of Li in view of Frohner or Li in view of Coillet and Frohner as taught by Amirzadeh-Asl because Amirzadeh-Asl teaches that the barium sulfate is also obtained by precipitation of combined sulfate and barium containing solutions, is of high purity, and can be used as a filler in plastics (Abstract; Paragraphs [0011, 0012]).
The above combination differs from the claimed invention in that Li in view of Frohner/Amirzadeh-Asl or Li in view of Coillet, Frohner, and Amirzadeh-Asl do not specifically teach removing the washing fluid via the treated fluid outlet line, because the precipitate is removed prior to washing; however, the same result of washing the precipitate is obtained. It has been held that the order to steps is not critical absent a showing of new or unexpected results. see MPEP 2144.04IV.C. and Ex parte Rubin, 128 USPQ 440 (Bd. App. 1959) (Prior art reference disclosing a process of making a laminated sheet wherein a base sheet is first coated with a metallic film and thereafter impregnated with a thermosetting material was held to render prima facie obvious claims directed to a process of making a laminated sheet by reversing the order of the prior art process steps.). See also In re Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946) (selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results); In re Gibson, 39 F.2d 975, 5 USPQ 230 (CCPA 1930) (Selection of any order of mixing ingredients is prima facie obvious.) If washing is performed prior to barium sulfate removal, the washing liquid would be removed through one of two outlets, and since it is in liquid form, it would have been obvious to remove the washing liquid via the treated fluid outlet of Li in view of Frohner or Li in view of Coillet and Frohner.
Claims 12-15, 18, and 19 are rejected under 35 U.S.C. 103 as unpatentable over Li et al. (U.S. Patent Publication # 2019/0225867) in view of Coillet et al. (U.S. Patent # 4392959) and Frohner et al. (U.S. Patent # 3974039), hereinafter “Li”, “Coillet”, and “Frohner”.
With respect to claims 12, 13, and 19, Li teaches a seawater treatment system 100, considered as “a barium sulfate production system” and “an agitation unit” as seawater treatment unit 100 comprises a mixer (see Fig. 1; Paragraph [0027, 0028]), wherein the seawater treatment system 100 (“agitation unit”) is in fluid connection with an aqueous fluid feed line 102, a treated fluid outlet 57 (“configured to produce a treated fluid”) and a precipitate outlet 108 located at a bottom surface of seawater treatment system 100/agitation unit and configured to separate a BaSO4 precipitate (see Fig. 1; Paragraph [0029]); seawater comprising sulfate (“a sulfate contaminated water”) in fluid connection with the aqueous fluid feed line 102; and a barium source 104 (Paragraphs [0028, 0030]; Fig. 1).
Li does not specifically teach that the agitation unit/mixer comprises the treated fluid outlet line and precipitate outlet (Li teaches a mixer and settling vessel/tank in Paragraph [0030], wherein the settling vessel would have the precipitate outlet and treated fluid outlet line and be positioned after the mixer).
Coillet teaches a clarifier 17 which comprises a stirrer (“agitation unit”) which also comprises a supernatant outlet (“treated fluid outlet line”) and settled product slurry stream precipitate outlet from which barium sulfate precipitate is removed (Column 13, lines 27-61).
It would have been obvious to modify the mixer and settling vessel combination of Li for the formation and removal of barium sulfate with the clarifier of Coillet because Li teaches that the seawater treatment system 100 can comprise a clarifier, and Coillet teaches that seawater (Column 5, line 4-7) is treated in clarifier 17 by addition of a soluble barium ion source to form a barium sulfate precipitate with residual sulfate levels as low as 15 ppm in the treated supernatant (Column 13, lines 52-61). The foregoing modification results in clarifier that is an agitation unit that comprises precipitate outlet and treated fluid outlet as claimed.
Li does not specifically teach a sulfate contaminated water unit.
Coillet teaches preceding treatment steps which involve physical vessels (see for example, the clarifier mentioned in Column 6, lines 20-40) for feedwater which includes sulfate ions (Column 5, lines 4-19; Column 6, lines 14-30).
It would have been obvious to one of ordinary skill in the art at the time the invention was effectively filed to add the preceding clarifier of Coillet to the seawater treatment system/barium sulfate production system of Li because Li teaches that the seawater treated by the disclosed method/system can be previously processed to remove contaminants (Paragraph [0033]) and Coillet teaches removal of magnesium hydroxide contaminants in saline streams including seawater prior to precipitation of barium sulfate (Column 5, lines 4-7; Column 6, lines 20-63, and see Column 13 lines 27-62 which describes barium sulfate precipitation and removal, several steps later).
Neither Li nor Coillet specifically teach that the precipitate outlet reversibly opens and closes.
Frohner teaches sludge valve V provided at the bottom of a settling region in which sludge comprising barium sulfate is discharged intermittently or continuously (see Fig. 2; Column 5, lines 1-21, 34-37), meeting the limitations “reversibly opening and closing” a precipitation outlet.
It would have been obvious to one of ordinary skill in the art to add the sludge valve of Frohner to the precipitation outlet of Li or Li/Coillet because Frohner teaches that the sludge valve(s) allow for continuous or intermittent discharge of sludge comprising barium sulfate in response to the settling rate of the barium sulfate, such that if the settling level is high, the valve is in an open state, allowing for sludge discharge to be optimized as the sludge builds up (see Column 5, lines 10-21). The ordinary artisan would have recognized that having sludge valve(s) would provide the advantage of controlling barium sulfate sludge discharge within the treatment unit generating precipitate so as to not overload the seawater treatment device of Li, which receives seawater 102 for treatment for separation of salts, just as the system/method of Frohner (see Abstract; Fig. 2).
With respect to claims 14 and 15, Li in view of Coillet and Frohner teaches a treated seawater (“treated fluid”) collection unit as pump trucks 40 (see Li: Paragraphs [0024, 0030]; Fig. 1), wherein Li also teaches that a pump may be included in line 57 as a motive force to pump trucks 40 (“treated fluid collection unit”).
With respect to claim 18, the treated liquid outlet/supernatant outlet of Li in view of Coillet and Frohner is capable of being used as a washing fluid outlet.
Claims 16 and 17 are rejected under 35 U.S.C. 103 as unpatentable over Li et al. (U.S. Patent Publication # 2019/0225867) in view of Coillet et al. (U.S. Patent # 4392959) and Frohner et al. (U.S. Patent # 3974039) as applied to claim 15, and further in view of Colelli et al. (U.S. Patent # 4895665), hereinafter “Li”, “Coillet”, “Frohner”, and “Colelli”.
With respect to claims 16 and 17, Li in view of Coillet and Frohner is silent with respect to the recited filter.
Colelli teaches pumping clarified liquid through a 25 micron filter (“at least 2 microns”) (Column 6, lines 30-39).
It would have been obvious to one of ordinary skill in the art at the time the invention was effectively filed to add the filter of Colelli to the pump of Li in view of Coillet and Frohner because Li teaches that the clarified water is to be used as a fracturing fluid 58 (Paragraph [0026]), and Colelli teaches that clarified fluid from which barium sulfate has been removed (Column 5, lines 57-62) is pumped through 25 micron filters prior to directing the fluid into frac tanks or transfer trucks (Column 6, lines 30-39), which is where the fluid 58 of Li is pumped (Paragraphs [0023, 0023, 0026]).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CLARE M PERRIN whose telephone number is (571)270-5952. The examiner can normally be reached 9AM-6PM EST M-F.
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/CLARE M. PERRIN/
Primary Examiner
Art Unit 1779
/CLARE M PERRIN/Primary Examiner, Art Unit 1779 13 March 2026