DETAILED ACTION
This detailed action is in response to the amendments and arguments filed on 09/15/2025, and any subsequent filings.
Notations “C_”, “L_” and “Pr_” are used to mean “column_”, “line_” and “paragraph_”.
Claims 1-10 and 12-39 are pending.
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 Arguments
Claim Objections
Due to the Applicant’s amendment, the previous claim objection is removed.
Claim Rejections - 35 USC § 112
Due to the Applicant’s amendment, the previous 35 USC § 112 rejection is removed.
Claim Rejections - 35 USC § 103
Claim 1
The Applicant argues that none of the cited prior art discloses a residence time of under 10 hours (pgs. 12-13). This is unpersuasive because reference Siame teaches conducting test runs in batch mode for an 8-hour shift (Siame, pg. 48).
The Applicant argues that none of the cited prior art discloses the desire or advantage of such a residence time (pgs. 12-13). This is persuasive.
The Applicant argues that the centrifugal force of the Knelson Concentrator of Siame is not a gravity separator (pg. 13). This is unpersuasive because Siame refers to the Knelson Concentrator as a gravity separator (Siame, abstract and IV. Conclusions).
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., The Applicant argues that “SiMW”, which may have intended to read “Siame”, does not disclose any information on how much of the residual collection chemicals and/or other non-aqueous substances would be eliminated before the DAF (pg. 13)) 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).
In response to applicant's argument that the examiner has combined an excessive number of references (pgs. 12-13), reliance on a large number of references in a rejection does not, without more, weigh against the obviousness of the claimed invention. See In re Gorman, 933 F.2d 982, 18 USPQ2d 1885 (Fed. Cir. 1991).
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., unexpected synergy (pg. 13)) 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).
In response to applicant's argument that the combination of features has a unique, unexpected synergy (pg. 13), 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).
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).
Response to Amendment
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, 4-6, 12-17, 19-20, and 22 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Publication US20160310956A1 (‘Filmer’) in view of U.S. Patent US3782539A (‘Painter’) and in further view of Publication Treatment and water reuse of lead-zinc sulphide ore mill wastewaters by high rate dissolved air flotation (‘Azevedo’, Minerals Engineering, Volume 127, October 2018, Pages 114-121) and in further view of Publication Feasibility Study on Physical Beneficiation of Low-Grade PGM Flotation Tailings using Spiral Classifiers and Enhanced Gravity Separators (‘Siame’, 2nd International Conference on Trends in Industrial and Mechanical Engineering (ICTIME'2013) Sept 17-18, 2013 Hong Kong).
The Applicant’s claims are directed towards a method.
Regarding Claims 1, 4-6, 12-17, 19-20, and 22¸ Filmer teaches a method of treating process water of a flotation plant for the recovery of a valuable material, the flotation plant comprising a mineral flotation line (abstract), the mineral flotation line comprising
- a grinding mill (Fig. 1, [0050], stage 14);
- a classification circuit for classifying a feed of ground ore from the grinding mill into
classifier overflow and classifier underflow (Fig. 1, [0050], size selector 16); and
- a mineral flotation circuit for treating classifier overflow as infeed of ore particles comprising valuable material suspended in slurry, the flotation circuit comprising a rougher part for the separation of slurry infeed into rougher overflow of recovered valuable material and rougher underflow of reject (Fig. 1, [0050], coarse particle flotation circuit 18), and a cleaner part arranged to receive rougher overflow from the rougher part as slurry infeed (Fig. 1, [0050], secondary flotation step 32), for the separation of slurry into cleaner overflow of recovered valuable material and cleaner underflow ([0052-0053]),
the flotation plant further comprising a process water circuit for treating underflow and/or overflow of the mineral flotation line, the process water circuit comprising a solid-liquid separator (Fig. 1, [0053], thickener 50) for dewatering underflow (Fig. 1, [0061], tailings of dashed line 62) and/or overflow of the mineral flotation line to separate sediment from supernatant comprising at least water (Fig. 1, [0053], water 52) and unrecovered fine particles comprising valuable material (Fig. 1, [0053], thickened tailings 54); and a recover water tank for collecting process water comprising overflow and/or underflow from the mineral flotation line (Fig. 1, [0052-0053], reservoir 26).
Filmer does not teach cleaner underflow being arranged to flow back into the rougher part as slurry infeed, a gravitational solid-liquid separator, and prior to leading supernatant from the gravitational solid-liquid separator into the recover water tank, supernatant is subjected to cleaning flotation, in which at least 90 % of the flotation gas bubbles have a size from 0.2 to 250 μm, in a cleaning flotation unit for collecting at least unrecovered fine particles comprising valuable material; for separating fine particles comprising valuable material from the supernatant into cleaning flotation overflow as recovered valuable material; and for forming purified process water as cleaning flotation underflow; and in that purified process water is recirculated into the mineral flotation line, or collected into the recover water tank as collected process water, and wherein the residence time of overflow and/or underflow from the mineral flotation line in the gravitational solid-liquid separator is under 10 hours.
Painter also relates to a method of treating process water of a flotation plant for the recovery of a valuable material, the flotation plant comprising a mineral flotation line (abstract), including cleaner (Figs. 1-2, C4, L7-9, cleaner flotation cells 14) underflow being arranged to flow back into the rougher part (Figs. 1-2, C4, L3-5, rougher flotation cells 13) as slurry infeed (Figs. 1-2, C4, L9-11).
Azevedo also relates to a method of treating process water of a flotation plant for the recovery of a valuable material, the flotation plant comprising a mineral flotation line (abstract), including prior to leading supernatant from the gravitational solid-liquid separator into the recover water tank (Fig. 1), supernatant is subjected to cleaning flotation, in which at least 90 % of the flotation gas bubbles have a size from 0.2 to 250 μm, in a cleaning flotation unit for collecting at least unrecovered fine particles comprising valuable material (dissolved air flotation (DAF) microbubbles have a bubble size distribution of 20-80 µm, pg. 115, Pr5); for separating fine particles comprising valuable material from the supernatant into cleaning flotation overflow as recovered valuable material (wastewater was treated using DAF to produce reuse water and floated solids, pg. 117, Fig. 3); and for forming purified process water as cleaning flotation underflow (wastewater was treated using DAF to produce reuse water and floated solids, pg. 117, Fig. 3); and in that purified process water is recirculated into the mineral flotation line, or collected into the recover water tank as collected process water (the treated water was recycled for microbubble generation and returned to a vessel for water recirculation, pg. 117, left column, last Pr).
Siame also relates to a method of treating process water of a flotation plant for the recovery of a valuable material (abstract), including that the residence time of overflow and/or underflow from the mineral flotation line in the gravitational solid-liquid separator is under 10 hours (pg. 48, flow rate into gravity separator Knelson Concentrator was 1 ton/hr for an 8-hour shift).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to arrange the cleaner underflow of Filmer to flow back into the rougher part as slurry infeed, as demonstrated by Painter, for retreatment (Painter, C4, L9-11). It would have been obvious to subject the supernatant Filmer and Painter to cleaning flotation prior to leading supernatant into the recover water tank, as demonstrated by Azevedo, because, due to the cyclic enrichment of deleterious chemical compounds, flotation requires good quality water as some ions, colloids, and suspended solids readily interfere in the mechanism of bubble-particle interactions, pulp rheology and froth stability, thus giving rise to a need for process water treatment, such as via DAF, to reduce the concentration of these substances that may cause gangue activation, separation selectivity decreases, and froth problems (Azevedo, pg. 114, right column, last Pr – pg. 115, left column, last Pr). It would have been obvious to choose the residence time in the gravitational solid-liquid separator in the method of Filmer, Painter and Azevedo, such as the residence time of Siame, because settling rate depends on mineral density (Siame, pg. 47, right column, last Pr-pg. 48, left column, Pr1). Furthermore, both Filmer and Siame involve a gravitational solid-liquid separator for treating underflow and/or overflow (Filmer, [0052-0053] and Siame, abstract) from the beneficiation of platinum group metals (Filmer, [0016] and [0023] and Siame, abstract).
Additional Disclosures Included:
Claim 4: the process water circuit comprises a second gravitational solid-liquid separator (Painter, Figs. 1-2, C3, L61-66, thickener 11) for dewatering classifier overflow (Painter, Figs. 1-2, C3, L61-66, classifier 7) to separate second sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material (Painter, C3, L61-66); second sediment led into the mineral flotation circuit as slurry infeed (Painter, Figs. 1-2, C4, L3-7, thickener underflow is passed to rougher flotation cells 9); and supernatant collected into the recover water tank as collected process water (Painter, C3, L61-66, thickener overflow is removed for reuse in the process) (It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the second gravitational solid-liquid separator of Painter and the method of the combination of Filmer, Painter, Azevedo and Siame to produce a fine slurry (Painter, C6, L14-16) and remove water for reuse in the process (Painter, C3, L61-66)).
Claim 5: the process water circuit comprises a third gravitational solid-liquid separator for dewatering cleaner overflow from the flotation circuit (Filmer, Fig. 1, [0052], concentrate from secondary flotation steps 32 is sent to concentrate thickener 36) to separate third sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material; supernatant collected into the recover water tank as collected process water (Filmer, [0052], reservoir 26).
Claim 6: the process water circuit comprises a fourth gravitational solid-liquid separator for dewatering rougher underflow from the flotation circuit (Filmer, Fig. 1, [0061], tailings are sent to tailings thickener 50) to separate fourth sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material; supernatant collected into the recover water tank as collected process water (Filmer, Fig. 1, [0053], reservoir 26).
Claim 12: prior to leading supernatant from a gravitational solid-liquid separator into cleaning flotation, supernatant is led into a separator overflow tank (thickener tailings overflow is sent to a wastewater storage tank (Azevedo, Fig. 1) before being subjected to a cleaning flotation (Azevedo, pg. 116, section 2.1. Synthetic wastewaters and reagents)).
Claim 13: prior to leading supernatant from a gravitational solid-liquid separator into cleaning flotation, the supernatant is led into mixing unit for chemically conditioning supernatant by adding a coagulant and/or a flocculant to flocculate at least fine particles comprising valuable material in supernatant (the flotation plant wastewater, which may be thickener tailings overflow (Azevedo, Fig. 1), is treated with a polymer flocculant solution, allowing the formation of stable flocs (Azevedo, pg. 116, right column) of the metal precipitates (Azevedo, pg. 116, left column, section 2.1. Synthetic wastewaters and reagents) which are ferric hydroxide, serving as a carrier for the removal of heavy metals (Azevedo, pg. 115, right column, last Pr)).
Claim 14: the coagulant is chosen from a group comprising: inorganic collector, aluminum salts, iron salts, organic coagulants (a ferric hydroxide carrier for the removal of heavy metals (Azevedo, pg. 115, right column, last Pr) where ferric hydroxide precipitation facilitates the incorporation of heavy metal ions directly into the precipitate matrix (Azevedo, pg. 118, right column, Pr1).
Claim 15: coagulant is added into supernatant in an amount of 1 to 2000 ppm (ferric chloride used to form ferric hydroxide precipitates (Azevedo, pg. 116, section 2.1. Synthetic wastewaters and reagents). The ferric chloride solution was added in an amount resulting in Fe3+ concentrations of 15-20 mg/L, or 15-20 ppm when converted (Azevedo, pg. 116, section 2.2.2. Preparation of wastewater for the pilot plant trials)).
Claim 16: the flocculant is chosen from a group comprising: natural polymers, synthetic flocculants (cationic polyacrylamide flocculant, Azevedo, pg. 116, section 2.1. Synthetic wastewaters and reagents, last Pr).
Claim 17: flocculant is added into supernatant in an amount of 1 to 100 ppm (a polymer flocculant that was added to give flocculant concentrations in the range of 0.2-2 mg/L, or 0.2-2 ppm when converted (Azevedo, pg. 116, section 2.2.3. Flocculation-DAF unit)).
Claim 19: the pH of the supernatant is adjusted to 6-12 prior to leading the supernatant into a cleaning flotation unit (the wastewater pH is adjusted to 6.5-7.5 (Azevedo, pg. 116, section 2.1. Synthetic wastewaters and reagents) prior to DAF performance (Azevedo, pg. 116, right column)).
Claim 20: the cleaning flotation unit is a dissolved gas flotation (DAF) unit (the wastewater is treated with DAF, Azevedo, abstract).
Claim 22: the valuable material is Pt (the ore may contain Pt, Filmer, [0023]).
Claims 2-3, 8 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Publication US20160310956A1 (‘Filmer’), U.S. Patent US3782539A (‘Painter’), Publication Treatment and water reuse of lead-zinc sulphide ore mill wastewaters by high rate dissolved air flotation (‘Azevedo’, Minerals Engineering, Volume 127, October 2018, Pages 114-121) and Publication Feasibility Study on Physical Beneficiation of Low-Grade PGM Flotation Tailings using Spiral Classifiers and Enhanced Gravity Separators (‘Siame’, 2nd International Conference on Trends in Industrial and Mechanical Engineering (ICTIME'2013) Sept 17-18, 2013 Hong Kong) as applied to claim 1 above, and further in view of U.S. Patent US3622087A (‘Oltmann’).
The Applicant’s claims are directed towards a method.
Regarding Claims 2-3, 8 and 10, the combination of Filmer, Painter, Azevedo and Siame teaches the method of Claim 1, except that the process water circuit comprises a first gravitational solid-liquid separator for dewatering classifier underflow to separate first sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material; first sediment arranged to flow into a filtering circuit for the recovery of valuable material and supernatant collected into the recover water tank as collected process water.
Oltmann also relates to a method of treating process water of a flotation plant for the recovery of a valuable material (abstract), including that the process water circuit comprises a first gravitational solid-liquid separator for dewatering classifier underflow to separate first sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material (thickeners dewater flotation tailings (C4, L66-75 and C3, L1-7) derived from classifier underflow (C4, L32-40)); first sediment arranged to flow into a filtering circuit for the recovery of valuable material and supernatant collected into the recover water tank as collected process water (thickened sludge may be further dewatered on filters or the like (C1, L38-44) and the overflows are available as operating water in the system (C5, L22-32)).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the first gravitational solid-liquid separator for dewatering classifier underflow of Oltmann and the method of the combination of Filmer, Painter, Azevedo and Siame so overflows from thickeners are available as operating water (Oltmann, C5, L40-44).
Additional Disclosures Included:
Claim 3: prior to leading supernatant from the first gravitational solid-liquid separator into the recover water tank, supernatant is subjected to cleaning flotation, in which at least 90 % of the flotation gas bubbles have a size from 0,2 to 250 μm, in a first cleaning flotation unit for collecting at least unrecovered fine particles comprising valuable material (flotation plant wastewaters, which may be thickener tailings overflow (Azevedo, Fig. 1), were treated using DAF having microbubbles that have a bubble size distribution of 20-80 µm (Azevedo, pg. 115, Pr5), producing reuse water and floated solids (Azevedo, pg. 117, Fig. 3) containing fractions of tailings and concentrates from sulphide (lead-zinc) bench flotation (Azevedo, pg. 116, left column, section 2.1. Synthetic wastewaters and reagents));
for separating fine particles comprising valuable material from supernatant into cleaning flotation overflow as recovered valuable material; and for forming purified process water as cleaning flotation underflow (DAF produced reuse water and floated solids (Azevedo, pg. 117, Fig. 3) containing fractions of tailings and concentrates from sulphide (lead-zinc) bench flotation (Azevedo, pg. 116, left column, section 2.1. Synthetic wastewaters and reagents));
and in that purified process water is recirculated into the mineral flotation line, or collected into the recover water tank as collected process water (the treated water was recycled for microbubble generation and returned to a vessel for water recirculation, Azevedo, pg. 117, left column, last Pr).
Claim 8: prior to leading overflow and/or underflow from the mineral flotation line to a gravitational solid-liquid separator, the concentration of overflow and/or underflow is adjusted to 0,5 to 15 w-% (the overflow and/or underflow has a concentration on the order of 0.5% before being subjected to thickening, Oltmann, C4, L41-54) (It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the concentration of Oltmann and the method of the combination of Filmer, Painter, Azevedo and Siame to recover operating water with a relative minimum of thickening area (Oltmann, C2, L44-56)).
Claim 10: at least 40% of fine particles comprising valuable material, unrecovered in the mineral flotation line, are recovered from supernatant of a gravitational solid-liquid separator (Oltmann teaches that the thickener has a feed that comprises 25,000 gallons per minute of secondary slimes with a solids content of 0.5% and 17,000 gallons per minute of primary slimes with a solids content of 4% (Oltmann, col. 5, line 70-col. 7, line 13). The overall solids content mass is calculated thusly:
25,000 gal ×(3.78 L)/gal×(1 kg water)/(1 L water)×0.5 wt% solids=472.5 kg solids from secondary slimes
A similar calculation was repeated for the primary slimes to yield a feed solids content of 3042.9 kg solids (per minute). The underflow produced by the thickener has a volume of 5210 gallons per minute at a solids content of 5-6%, or 1603.7 kg solids – 1924.4 kg solids (per minute) (It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the fine particle recovery of Oltmann and the method of the combination of Filmer, Painter, Azevedo and Siame to produce an economical product and recovery overflow as process water (Oltmann, C5, L13-22)).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Publication US20160310956A1 (‘Filmer’), U.S. Patent US3782539A (‘Painter’), Publication Treatment and water reuse of lead-zinc sulphide ore mill wastewaters by high rate dissolved air flotation (‘Azevedo’, Minerals Engineering, Volume 127, October 2018, Pages 114-121) and Publication Feasibility Study on Physical Beneficiation of Low-Grade PGM Flotation Tailings using Spiral Classifiers and Enhanced Gravity Separators (‘Siame’, 2nd International Conference on Trends in Industrial and Mechanical Engineering (ICTIME'2013) Sept 17-18, 2013 Hong Kong) as applied to claim 1 above, and further in view of U.S. Patent US9956563B1 (‘Roa’).
The Applicant’s claim is directed towards a method.
Regarding Claim 7, the combination of Filmer, Painter, Azevedo and Siame teaches the method of Claim 1, including subjecting collected process water to cleaning flotation, in which at least 90 % of the flotation gas bubbles have a size from 0,2 to 250 μm, for collecting at least unrecovered fine particles comprising valuable material (flotation plant wastewaters, which may be thickener tailings overflow (Azevedo, Fig. 1), were treated using DAF having microbubbles that have a bubble size distribution of 20-80 µm (Azevedo, pg. 115, Pr5), producing reuse water and floated solids (Azevedo, pg. 117, Fig. 3) containing fractions of tailings and concentrates from sulphide (lead-zinc) bench flotation (Azevedo, pg. 116, left column, section 2.1. Synthetic wastewaters and reagents));
for separating fine particles comprising valuable material from supernatant into cleaning flotation overflow as recovered valuable material; and for forming purified process water as cleaning flotation underflow (DAF produced reuse water and floated solids (Azevedo, pg. 117, Fig. 3) containing fractions of tailings and concentrates from sulphide (lead-zinc) bench flotation (Azevedo, pg. 116, left column, section 2.1. Synthetic wastewaters and reagents));
and in that purified process water is recirculated into the mineral flotation line (the treated water was recycled for microbubble generation and returned to a vessel for water recirculation, Azevedo, pg. 117, left column, last Pr).
The combination of Filmer, Painter, Azevedo and Siame does not teach a second cleaning flotation unit.
Roa also relates to a method of treating process water (abstract), including a second cleaning flotation unit (Fig. 1, C2, L34-35 and C3, L17-19).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include a second cleaning flotation unit to further process the water (Roa, C3, L17-19) by further separating out solids from the water, producing water having a low level of impurities (Roa, C3, L25-28, see C5, Table 1, rows Second and Thirteenth).
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Publication US20160310956A1 (‘Filmer’), U.S. Patent US3782539A (‘Painter’), Publication Treatment and water reuse of lead-zinc sulphide ore mill wastewaters by high rate dissolved air flotation (‘Azevedo’, Minerals Engineering, Volume 127, October 2018, Pages 114-121), Publication Feasibility Study on Physical Beneficiation of Low-Grade PGM Flotation Tailings using Spiral Classifiers and Enhanced Gravity Separators (‘Siame’, 2nd International Conference on Trends in Industrial and Mechanical Engineering (ICTIME'2013) Sept 17-18, 2013 Hong Kong) and U.S. Patent US3622087A (‘Oltmann’) as applied to claim 8 above, and further in view of Liller (US4164467A, Aug. 14, 1979) and Enkhbold (US 20110150625 A1, June 23, 2011).
The Applicant’s claim is directed towards a method.
Regarding Claim 9, the combination of Filmer, Painter, Azevedo, Siame and Oltmann teaches the method of Claim 8, except that the turbulent flow of overflow and/or underflow from the mineral flotation line is adjusted to a laminar flow as it is led into the gravitational solid-liquid separator.
Liller teaches maintaining streamlined laminar flow (Liller, abstract) to eliminate turbulence (Liller, C4, L1-12).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adjust turbulent flow to laminar flow, as demonstrated by Liller, prior to the gravitational solid-liquid separator because turbulence prevents solid phases settling out (Enkhbold, [0011]).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Publication US20160310956A1 (‘Filmer’), U.S. Patent US3782539A (‘Painter’), Publication Treatment and water reuse of lead-zinc sulphide ore mill wastewaters by high rate dissolved air flotation (‘Azevedo’, Minerals Engineering, Volume 127, October 2018, Pages 114-121) and Publication Feasibility Study on Physical Beneficiation of Low-Grade PGM Flotation Tailings using Spiral Classifiers and Enhanced Gravity Separators (‘Siame’, 2nd International Conference on Trends in Industrial and Mechanical Engineering (ICTIME'2013) Sept 17-18, 2013 Hong Kong) as applied to claim 1 above, and further in view of Dassey (Water 2012, 4, 1-11).
The Applicant’s claim is directed towards a method.
Regarding Claim 18, the combination of Filmer, Painter, Azevedo and Siame teaches the method of Claim 1, except that the temperature of supernatant is adjusted to 2-60 °C prior to leading it into a cleaning flotation unit.
Dassey teaches the effects of parameters such as power, pressure, temperature, hydraulic retention time, and air flow on dissolved air flotation (DAF) performance (abstract). Ice and water heaters were used to vary the water temperatures from 7, 14, 21, 28 and 35 °C (pg. 5, section 2.3.2. Temperature, reads on the claimed temperature range). Dassey teaches that bubble production decreased linearly with increasing temperature up to 21 °C, then further increases in temperature increased bubble production (pg. 7, section 3.3. Temperature).
It would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the water temperature prior to cleaning flotation and the method of Filmer, Painter, Azevedo and Siame based on the desired bubble production (Dassey, pg. 7, section 3.3. Temperature) while also maintaining an applicable temperature control (Dassey, abstract).
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Publication US20160310956A1 (‘Filmer’) in view of U.S. Patent US3782539A (‘Painter’) in view of Publication Treatment and water reuse of lead-zinc sulphide ore mill wastewaters by high rate dissolved air flotation (‘Azevedo’, Minerals Engineering, Volume 127, October 2018, Pages 114-121) in view of Publication Feasibility Study on Physical Beneficiation of Low-Grade PGM Flotation Tailings using Spiral Classifiers and Enhanced Gravity Separators (‘Siame’, 2nd International Conference on Trends in Industrial and Mechanical Engineering (ICTIME'2013) Sept 17-18, 2013 Hong Kong) as applied to claim 1 above, and further in view of Tian (Journal of Cleaner Production 174 (2018) 625-633).
The Applicant’s claim is directed towards a method.
Regarding Claim 21, the combination of Filmer, Painter, Azevedo and Siame teaches the method of Claim 1, except that the valuable material is Li.
Tian also relates to a method of treating process water of a flotation plant for the recovery of a valuable material (mica and feldspar are recycled from lithium tailings in an economical and environmentally-friendly way, abstract), the flotation plant comprising a mineral flotation line, the mineral flotation line comprising: - a grinding mill (pg. 627, section 2.2.2. Batch flotation tests, first paragraph);
- a classification circuit for classifying a feed of ground ore from the grinding mill into classifier overflow and classifier underflow (the powder samples were screened to four size fractions, pg. 626, section 2.1.1. Ore samples, Pr1); and
a mineral flotation circuit for treating ore particles comprising valuable material and suspended in slurry (flotation flowsheets shown in pg. 628, Fig. 4), the mineral flotation circuit comprising a rougher part for the separation of slurry infeed into rougher overflow of recovered valuable material and rougher underflow of reject (Fig. 4, roughing flotation), and a cleaner part arranged to receive rougher overflow from the rougher part as slurry infeed (Fig. 4, lithium concentrate from roughing flotation is sent to cleaning flotation I), for the separation of slurry into cleaner overflow of recovered valuable material (Fig. 4) and cleaner underflow arranged to flow back into the rougher part as slurry infeed (Fig. 4, lithium tailings from cleaning flotation I is sent back to roughing flotation).
It would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that lithium can be recovered by the arrangement of the combination of Filmer, Painter, Oltmann and Azevedo, as demonstrated by Tian (Tian, Fig. 4), because both Filmer and Tian involve a mineral flotation line comprising a grinding mill, a classification circuit and a mineral flotation circuit for treating ore particles comprising valuable material and suspended in slurry, the mineral flotation circuit comprising a rougher part for the separation of slurry infeed into rougher overflow of recovered valuable material and rougher underflow of reject, and a cleaner part arranged to receive rougher overflow from the rougher part as slurry infeed, for the separation of slurry into cleaner overflow of recovered valuable material and cleaner underflow arranged to flow back into the rougher part as slurry infeed, putting forward a flotation scheme aimed at improving the flotation performance of spodumene and recycling from lithium tailings in an economical and environmentally friendly way (Tian, abstract).
Claims 23, 26-32, and 36-38 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Publication US20160310956A1 (‘Filmer’) in view of U.S. Patent US3782539A (‘Painter’) and in further view of Publication Treatment and water reuse of lead-zinc sulphide ore mill wastewaters by high rate dissolved air flotation (‘Azevedo’, Minerals Engineering, Volume 127, October 2018, Pages 114-121) and in further view of U.S. Patent US9956563B1 (‘Roa’) and in further view of Publication Feasibility Study on Physical Beneficiation of Low-Grade PGM Flotation Tailings using Spiral Classifiers and Enhanced Gravity Separators (‘Siame’, 2nd International Conference on Trends in Industrial and Mechanical Engineering (ICTIME'2013) Sept 17-18, 2013 Hong Kong).
The Applicant’s claims are directed towards an apparatus.
Regarding Claims 23, 26-32, and 36-38, Filmer teaches an arrangement for treating process water of a flotation plant for the recovery of a valuable material, the flotation plant comprising a mineral flotation line (abstract), the mineral flotation line comprising
- a grinding mill (Fig. 1, [0050], stage 14);
- a classification circuit for classifying a feed of ground ore from the grinding mill into
classifier overflow and classifier underflow (Fig. 1, [0050], size selector 16); and
- a mineral flotation circuit for treating ore particles comprising valuable material suspended in slurry, the mineral flotation circuit comprising a rougher part for the separation of slurry infeed into rougher overflow of recovered valuable material and rougher underflow of reject (Fig. 1, [0050], coarse particle flotation circuit 18), and a cleaner part arranged to receive rougher overflow from the rougher part as slurry infeed (Fig. 1, [0050], secondary flotation step 32), for the separation of slurry into cleaner overflow of recovered valuable material and cleaner underflow ([0052-0053]),
the flotation plant further comprising a process water circuit for treating underflow and/or overflow of the mineral flotation line, the process water circuit comprising a gravitational solid-liquid separator (Fig. 1, [0052], concentrate thickener 36) for dewatering underflow and/or overflow of the mineral flotation line to separate sediment from supernatant comprising at least water (Fig. 1, [0052], water 46) and unrecovered fine particles comprising valuable material (Fig. 1, [0052], thickened concentrate 40); and a recover water tank for collecting process water comprising overflow and/or underflow from the mineral flotation line (Fig. 1, [0052-0053], reservoir 26).
Filmer does not teach cleaner underflow being arranged to flow back into the rougher part as slurry infeed, a gravitational solid-liquid separator, wherein the water treatment circuit further comprises a cleaning flotation unit employing flotation gas bubbles of which at least 90 % have a size from 0.2 to 250 μm, operationally connected to the gravitational solid-liquid separator for receiving supernatant prior to it being led into the recover water tank, and arranged to collect at least unrecovered fine particles comprising valuable material; to separate fine particles comprising valuable material from supernatant into cleaning flotation overflow as recovered valuable material; and to form purified process water as cleaning flotation underflow configured to be recirculated into the mineral flotation line, or collected into the recover water tank as collected process water, and wherein the gravitational solid-liquid separator is arranged to dewater underflow and/or overflow of the mineral flotation line such that the residence time of underflow and/or overflow is under 10 hours.
Painter also relates to an arrangement for treating process water of a flotation plant for the recovery of a valuable material (abstract), including cleaner (Figs. 1-2, C4, L7-9, cleaner flotation cells 14) underflow being arranged to flow back into the rougher part (Figs. 1-2, C4, L3-5, rougher flotation cells 13) as slurry infeed (Figs. 1-2, C4, L9-11).
Azevedo also relates to an arrangement for treating process water of a flotation plant for the recovery of a valuable material (abstract), including the water treatment circuit further comprises a cleaning flotation unit employing flotation gas bubbles of which at least 90 % have a size from 0.2 to 250 μm (dissolved air flotation (DAF) microbubbles have a bubble size distribution of 20-80 µm, pg. 115, Pr5) for receiving supernatant prior to it being led into the recover water tank (Fig. 1), and arranged to collect at least unrecovered fine particles comprising valuable material; to separate fine particles comprising valuable material from supernatant into cleaning flotation overflow as recovered valuable material (wastewater was treated using DAF to produce reuse water and floated solids, pg. 117, Fig. 3); and to form purified process water as cleaning flotation underflow (wastewater was treated using DAF to produce reuse water and floated solids, pg. 117, Fig. 3) configured to be recirculated into the mineral flotation line, or collected into the recover water tank as collected process water (the treated water was recycled for microbubble generation and returned to a vessel for water recirculation, pg. 117, left column, last Pr).
Roa also relates to an arrangement for treating process water (abstract), including that the cleaning flotation unit is operationally connected to the gravitational solid-liquid separator (A source waste stream is passed through a plate separator, producing a first solids fraction (Roa, 3rd stream) and a first effluent fraction, where the first solids fraction passes through a first press to produce a second solids fraction (Roa, 5th stream) and a second effluent fraction (Roa, 4th stream, C3, L46-56, Fig. 1). The second effluent fraction (Roa, 4th stream) and first effluent fraction (Roa, 2nd stream) are fed to a dissolved air flotation device (Roa, C3, L46-56)).
Siame also relates to an arrangement for treating process water of a flotation plant for the recovery of a valuable material (abstract), including that the gravitational solid-liquid separator is arranged to dewater underflow and/or overflow of the mineral flotation line such that the residence time of underflow and/or overflow is under 10 hours (pg. 48, flow rate into Knelson Concentrator was 1 ton/hr for an 8-hour shift).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to arrange cleaner underflow to flow back into the rougher part as slurry infeed, as demonstrated by Painter, for retreatment (Painter, C4, L9-11). It would have been obvious to subject supernatant to cleaning flotation prior to leading supernatant into the recover water tank, as demonstrated by Azevedo, because, due to the cyclic enrichment of deleterious chemical compounds, flotation requires good quality water as some ions, colloids, and suspended solids readily interfere in the mechanism of bubble-particle interactions, pulp rheology and froth stability, thus giving rise to a need for process water treatment, such as via DAF, to reduce the concentration of these substances that may cause gangue activation, separation selectivity decreases, and froth problems (Azevedo, pg. 114, right column, last Pr – pg. 115, left column, last Pr). It would have been obvious operationally connect the cleaning flotation unit to the gravitational solid-liquid separator, as demonstrated by Roa, to further separate solids from the effluent (Roa, C3, L 25-39). It would have been obvious to choose the residence time in the gravitational solid-liquid separator in the method of Filmer, Painter, Azevedo and Roa, such as the residence time of Siame, because settling rate depends on mineral density (Siame, pg. 47, right column, last Pr-pg. 48, left column, Pr1). Furthermore, both Filmer and Siame involve a gravitational solid-liquid separator for treating underflow and/or overflow (Filmer, [0052-0053] and Siame, abstract) from the beneficiation of platinum group metals (Filmer, [0016] and [0023] and Siame, abstract).
Additional Disclosures Included:
Claim 26: the process water circuit comprises a second gravitational solid-liquid separator (Painter, Figs. 1-2, C3, L61-66, thickener 11) arranged to dewater classifier overflow (Painter, Figs. 1-2, C3, L61-66, classifier 7) to separate second sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material (Painter, C3, L61-66); second sediment arranged to flow into the mineral flotation circuit as slurry infeed (Painter, Figs. 1-2, C4, L3-7, thickener underflow is passed to rougher flotation cells 9); and supernatant configured to be collected into the recover water tank as collected process water (Painter, C3, L61-66, thickener overflow is removed for reuse in the process) (It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the second gravitational solid-liquid separator of Painter and the method of the combination of Filmer, Painter, Azevedo and Siame to produce a fine slurry (Painter, C6, L14-16) and remove water for reuse in the process (Painter, C3, L61-66)).
Claim 27: the process water circuit comprises a third gravitational solid-liquid separator arranged to dewater cleaner overflow from the mineral flotation circuit (Filmer, Fig. 1, [0052], concentrate from secondary flotation steps 32 is sent to concentrate thickener 36) to separate third sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material; supernatant collected into the recover water tank as collected process water (Filmer, [0052], reservoir 26).
Claim 28: the process water circuit comprises a fourth gravitational solid-liquid separator arranged to dewater rougher underflow from the flotation circuit (Filmer, Fig. 1, [0061], tailings are sent to tailings thickener 50) to separate fourth sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material; supernatant collected into the recover water tank as collected process water (Filmer, Fig. 1, [0053], reservoir 26).
Claim 29: the process water circuit further comprises a second cleaning flotation unit (Roa, C3, L17-19) employing flotation gas bubbles of which at least 90 % have a size from 0,2 to 250 μm (flotation plant wastewaters, which may be thickener tailings overflow (Azevedo, Fig. 1), were treated using DAF having microbubbles that have a bubble size distribution of 20-80 µm (Azevedo, pg. 115, Pr5)),
operationally connected to the recover water tank for receiving collected process water (The second effluent fraction (Roa, 4th stream) and first effluent fraction (Roa, 2nd stream) are fed to a dissolved air flotation device (Roa, C3, L46-56)),
and arranged to collect at least unrecovered fine particles comprising valuable material, to separate fine particles comprising valuable material from collected process water into cleaning flotation overflow as recovered valuable material, and to form purified process water as cleaning flotation underflow (treating the flotation plant wastewater produced reuse water and floated solids (Azevedo, pg. 117, Fig. 3) containing fractions of tailings and concentrates from sulphide (lead-zinc) bench flotation (Azevedo, pg. 116, left column, section 2.1. Synthetic wastewaters and reagents));
purified process water is configured to be recirculated into the mineral flotation line (the treated water was recycled for microbubble generation and returned to a vessel for water recirculation, Azevedo, pg. 117, left column, last Pr).
Claim 30: process water circuit comprises a separator overflow tank into which supernatant from a gravitational solid-liquid separator is configured to flow prior to being led into cleaning flotation (thickener tailings overflow is sent to a wastewater storage tank (Azevedo, Fig. 1) before being subjected to a cleaning flotation (Azevedo, pg. 116, section 2.1. Synthetic wastewaters and reagents)).
Claim 31: process water circuit further comprises a mixing unit into which supernatant from a gravitational solid-liquid separator is configured to flow prior to being led into cleaning flotation, the mixing unit arranged to chemically condition supernatant to flocculate at least fine particles comprising valuable material in supernatant (a rapid mixing chamber (Azevedo, pg. 117, Fig. 4, A, pg. 116, section 2.2.3. Flocculation-DAF unit) in which thickener tailings overflow (Azevedo, pg. 116, Fig. 1) are treated with a polymer flocculant solution prior to flotation in the flotation unit, comprising a bubble-floc contact zone (Azevedo, Fig. 4, C) and a separation zone (Azevedo, Fig. 4, D). The resulting flocs contain fine particles (Azevedo, pg. 116, section 2.2.2. Preparation of wastewater for the pilot plant trials) of tailings and concentrates from sulphide (lead-zinc) flotation (Azevedo, pg. 116, section 2.1. Synthetic wastewaters and reagents)).
Claim 32: the cleaning flotation unit is a dissolved gas flotation (DAF) unit (the wastewater is treated with DAF, Azevedo, abstract).
Claim 38: the residence time of overflow and/or underflow from the mineral flotation line in the gravitational solid-liquid separator is 0.5 to 8 hours (Siame, pg. 48, flow rate into Knelson Concentrator was 1 ton/hr for an 8-hour shift).
Claims 24-25 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Publication US20160310956A1 (‘Filmer’), U.S. Patent US3782539A (‘Painter’) and in further view of Publication Treatment and water reuse of lead-zinc sulphide ore mill wastewaters by high rate dissolved air flotation (‘Azevedo’, Minerals Engineering, Volume 127, October 2018, Pages 114-121), U.S. Patent US9956563B1 (‘Roa’) and Publication Feasibility Study on Physical Beneficiation of Low-Grade PGM Flotation Tailings using Spiral Classifiers and Enhanced Gravity Separators (‘Siame’, 2nd International Conference on Trends in Industrial and Mechanical Engineering (ICTIME'2013) Sept 17-18, 2013 Hong Kong) as applied to claim 23, and further in view of U.S. Patent US3622087A (‘Oltmann’).
The Applicant’s claims are directed towards an apparatus.
Regarding Claims 24-25, the combination of Filmer, Painter, Azevedo, Roa and Siame teaches the arrangement of Claim 23, except that the process water circuit comprises a first gravitational solid-liquid separator arranged to dewater classifier underflow to separate first sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material; first sediment arranged to flow into a filtering circuit for the recovery of valuable material and supernatant collected into the recover water tank as collected process water.
Oltmann also relates to a method of treating process water of a flotation plant for the recovery of a valuable material (abstract), including that the process water circuit comprises a first gravitational solid-liquid separator arranged to dewater classifier underflow to separate first sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material (thickeners dewater flotation tailings (C4, L66-75 and C3, L1-7) derived from classifier underflow (C4, L32-40)); first sediment arranged to flow into a filtering circuit for the recovery of valuable material and supernatant collected into the recover water tank as collected process water (thickened sludge may be further dewatered on filters or the like (C1, L38-44) and the overflows are available as operating water in the system (C5, L22-32)).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the first gravitational solid-liquid separator for dewatering classifier underflow of Oltmann and the method of the combination of Filmer, Painter, Azevedo and Siame so overflows from thickeners are available as operating water (Oltmann, C5, L40-44).
Additional Disclosures Included:
Claim 25: the water treatment circuit comprises a first cleaning flotation unit employing flotation gas bubbles of which at least 90 % have a size from 0.2 to 250 μm (flotation plant wastewaters, which may be thickener tailings overflow (Azevedo, Fig. 1), were treated using DAF having microbubbles that have a bubble size distribution of 20-80 µm (Azevedo, pg. 115, Pr5)),
operationally connected to the first gravitational solid-liquid separator for receiving supernatant (the second effluent fraction (Roa, 4th stream) and first effluent fraction (Roa, 2nd stream) are fed to a dissolved air flotation device (Roa, C3, L46-56)),
and arranged to collect at least unrecovered fine particles comprising valuable material; to separate fine particles comprising valuable material from supernatant into cleaning flotation overflow as recovered valuable material (DAF produces reuse water and floated solids (Azevedo, pg. 117, Fig. 3) containing fractions of tailings and concentrates from sulphide (lead-zinc) bench f