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 Claims are newly amended.
Response to Arguments
Applicant's arguments filed 5/25/26 have been fully considered but they are not persuasive.
The remarks argue on page 9, the following:
Applicant's invention is characterized by an advantage of removing problematic organic
matter prior to the phosphoric acid process. The removal of organic matter at this stage allows for efficient application of a later flotation process, which would otherwise be unable of function efficiently due to the impact of organic matter on the selective chemistry of the flotation process.
As a result of being able to use a flotation process, Applicant's invention permits processing of lower grade phosphate ore with effective removal of gangue minerals
(contaminants) to improve the quality of the final product (feedstock) to the phosphoric acid process. This leads to higher efficiencies in the phosphoric acid process and allows for the production of higher quality acid products due to the higher quality acid produced.
Applicant notes that Examiner appears to have conflated aspects of the Cited
References against features as recited in the claims. A feature of the claims as presented is to remove organic material as a first process prior to screening, by mixing the ore with sulfuric acid and by not applying external heating. Distinguishing features of the claim 1 over specific Cited References are identified below.
Gradl, for example, discloses exemplary conditioning of the ore using either sulfuric
acids and heating the acid under pressure before treatment with an absorbent. See its abstract.
Gradl removes impurities at a later, different stage from Applicant's process. Gradl's order of processing step, effectively prevents it from being able to obtain Applicant's above-mentioned grade processing efficiencies. Gradl states that when phosphate ore is digested with sulfuric acids, sulfates become the main impurity component, forming heavily contaminated phosphoric acid. In addition there are organic impurities and organic compounds in the phosphoric acid due to the organic compounds being present in the feedstock for its phosphoric acid plant. As such, Gradl's disclosure is not fully on point to the features of Applicant's invention as claimed.
The remarks are respectfully not persuasive. It was explained in the prior rejection and in this rejection that Duyvesteyn already describes processing the ore using sulfuric acid at room temperature, therefore the same process used the same way would have the same effectiveness. Applicant has not pointed out features of the process that differ from the claimed process that would remove organic contaminants that the Duyvesteyn does not have.
As to the Gradl reference, given the claim amendments, this reference is removed.
Next, the remarks argue the following:
Duyvesteyn discloses methods for extracting scandium from a feedstock of a copper ore. Its process commences with an ore feedstock such as, for example, a scandium- containing, copper bearing ore of the type obtained from a porphyry copper deposit per its para. 13). Its para. 52 refers to an ion exchange resin. There is no reference here to sulfuric acid. Duyvesteyn is not relevant prior art as Applicant's invention is directed to processing phosphate ore and further Duyvesteyn makes no reference to organic matter removal using sulfuric acid.
The remarks are respectfully not persuasive. Paragraph 52 of Duyvesteyn describes atmospheric pressure acid leaching of the ore using sulfuric acid (para. 52).
Next, page 10 of the remarks argues the following:
Pingitore discloses methods for the extraction and recovery of yttrium and light and heavy rare earth elements for an ore containing the mineral yttroflourite. Pingitore has no disclosure of phosphate ore and makes no reference to organic matter. Pingitore's process requires crushing the ore (see its para. 10) into a grain size between 2mm and 20mm. It is noted that crushing of ores is an important step in all mineral processing facilities. Effectively all mineral processing beneficiation plants use a screen for the slurry streams and these screen sizes are based on what size fraction the targeted mineral is best liberated or separated. As such, in order to recover any type of mineral (particularly using flotation) the mineral must be sufficiently ground and separated (liberated) in order to recover the targeted mineral. Mineral liberation is the process of reducing a large piece of ore into smaller particles so that each individual particle consists primarily of a single mineral. This is crucial for mineral processing because it allows the separation of valuable minerals from waste material (gangue) using physical or chemical separation methods, which cannot effectively separate minerals if they are locked with the same particle. Pingitore's process crushes the ore and deposits the ore onto a pad where it is sprayed with either sulfuric acid or hydrochloric acid which, over time, leaches out the rare earth minerals. Examiner's application of Pingitore to posit a comparison to screen sizes is not meaningful, as every beneficiation plant does some type of screening. As such, it is not sufficient to simply cite Pingitore's screening disclosure to Applicant's process as claimed as Pingatore is not relevant to removing organic matter from phosphate ore by the use of attrition scrubbing.
The remarks are respectfully not persuasive. The remarks argue that Pingitore does not disclose phosphate ore, but Claim 1 does not limit the claims to this feature. Therefore, any ore would read on the claims. As to the other arguments, they are not persuasive. Applicant admits that “every benefication plant does not some kind of screening” (remarks, page 10) and that it is not sufficient to simply cite to Pingitore’s screening disclosure because it is not relevant to removing organic matter from phosphate ore. This is disputed. The removal of organic matter was previously treated in the Duyvesteyn reference.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1, 2, 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Duyvesteyn (US Pub.: 2016/0153070) and in view of Rissanen (WO 2014/118436) and in view of Pingitore (US Pub.: 2016/0138133).
Duyvesteyn describes a system and method for acid leaching scandium-bearing ores (title). The ore can be a laterite ore (para. 13). The process uses sulfuric acid to leach the ore to separate some metal compounds from the rest of the ore (para. 52). More specifically, Duyvesteyn describes treating ore with sulfuric acid at room temperature (para. 80) to remove impurities (abstract). Impurities can include silicates (para. 36, 56). As to the pressure, Duyvesteyn does not specifically teach ambient pressure (see Claim 20 of current claims), however, without a recitation of adding pressure, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the pressure applied would be ambient pressure.
As to the sulfuric acid removing organic contaminants, since the process uses the same reagents together, in the same way, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that they would react in the same way.
As to the screening step, Rissanen describes a method for recovering metals from ores (title). The process involves combing the ore in a slurry (page 4, lines 6-12) and then acidified (page 5, lines 11-15). Rissanen then states that the grains have a size of from 0.6 to 1.2mm (page 7, lines 10-13). Furthermore, Rissanen states that the largest grains consist of silicates and these grains can be slurried and then screened off from the rest of the ore ranging in size from 0.6 to 0.7mm by using a screen (pg 7, lines 10-16).
A prima facie case of obviousness exists where the claimed ranges and prior art ranges overlap or are close enough that one skilled in the art would have expected them to have the same properties. See MPEP 2144.05 I.”
Therefore, since Duyvesteyn explains that silicates are some of the impurities in the ore Rissanen describes a smaller size of 0.6 to 0.7mm that can be used to eliminate silicates larger than this size range, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a screen with a size range of 0.6 to 0.7mm, in order to separate these grains in this size range from the larger grains, as taught by Rissanen for use in the process of Lowe because Rissanen explains that the larger silicate particles are not desirable.
As to the initial size of the ore, the references do not teach that the initial ore size is 4mm or less.
As to the size, Pingitore teaches a method of extracting and recovering rare earth elements (title) from ores (para. 10). Scandium is a rare earth element (para. 21). The process of Pingitore contacts the ore with sulfuric acid to recover the metals (para. 8, 10). Prior to contacting the ore with sulfuric acid, the reference explains that the ore can be crushed to a size of 2-20mm (para. 10).
A prima facie case of obviousness exists where the claimed ranges and prior art ranges overlap or are close enough that one skilled in the art would have expected them to have the same properties. See MPEP 2144.05 I.”
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to crush the ore down to a size of from 2-20mm, as taught by Pingitore for use with the leaching process of Duyvesteyn and Rissanen because crushing the ore down to this size prior to leaching with sulfuric acid would lead to predictable and expected leaching results.
As to Claim 2, Duvesteyn teaches that after leaching with sulfuric acid, the mixture is subjected to solid-liquid separation and washing to yield a tailing and a leachate (para. 108).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the tailing would contain all the contaminants in the ore, to include any organic contaminants.
Claim(s) 1, 11, 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nie (CN 108672102) and in view of Rissanen (WO 2014/118436).
Nie describes a method of processing a phosphorous-containing ore (title). The process crushes and mills the ore (abstract “Novelty”). The mixture is in a solution while milled (abstract, “Novelty”) and ground until the particles are less than 0.074mm in size (abstract, “Novelty”). The pH of the solution is adjusted using sulfuric acid (abstract, “Novelty”). The mixture is stirred (abstract, “Novelty”). Since the pH is adjust to the desired level using acid, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that this can be considered “maintaining the pH level in the slurry to a pH range”, while mixing the slurry.
The process is performed at room temperature (para. 9). As to the pressure, Nie does not state that the pressure is ambient, but without a recitation of pressurizing the reaction, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the pressure applied is ambient pressure.
As to the sulfuric acid removing organic contaminants, since the process uses the same reagents together, in the same way, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that they would react in the same way.
As to the screening step, Rissanen describes a method for recovering metals from ores (title). The process involves combing the ore in a slurry (page 4, lines 6-12) and then acidified (page 5, lines 11-15). Rissanen then states that the grains have a size of from 0.6 to 1.2mm (page 7, lines 10-13). Furthermore, Rissanen states that the largest grains consist of silicates and these grains can slurried and then screened off from the rest of the ore ranging in size from 0.6 to 0.7mm by using a screen (pg 7, lines 10-16).
Therefore, since Nie describes reducing the particles sizes, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a screen with a size range of 0.6 to 0.7mm, in order to separate these grains in this size range from the larger grains, as taught by Rissanen for use in the process of NIe because Rissanen explains that the larger silicate particles are not desirable.
As to the features in the preamble, the method is effective for removing or releasing organics from ores because the same process used the same way with the same compounds would have the same effect.
A preamble is generally not accorded any patentable weight where it merely recites the purpose of a process or the intended use of a structure, and where the body of the claim does not depend on the preamble for completeness but, instead, the process steps or structural limitations are able to stand alone. See In re Hirao, 535 F.2d 67, 190 USPQ 15 (CCPA 1976) and Kropa v. Robie, 187 F.2d 150, 152, 88 USPQ 478, 481 (CCPA 1951).
Claim(s) 2, 3, 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nie and Rissanen as applied to claim 1 above, and further in view of Drechsel (US Pat.: 4393032).
The references do state that the rock is a phosphate ore (Claim 4), but they not state separation of the two phases (Claim 2) or use of an attrition scrubbing device (Claim 3).
Drechsel describes a process for processing phosphate rock (abstract). The process combines the rock (col. 6, line 26) with sulfuric acid (col. 6, lines 33-35). The product is then fed to a crystallizer (col. 6, lines 35-37) and then is filtered (col. 6, lines 57-58). The solution is then recycled (Fig. 2, 16 and 20).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to separate the streams into a solids stream and a liquid stream (due to filtration), as taught by Dreschel for use with the process of Nie and Rissanen because the liquid stream can be recycled for further use.
As to Claim 3, Nie describes ball milling the ore (see above), but not use of an attrition scrubbing device.
Dreschsel explains that in the process a ball mill step may be used, but alternatively, the device used can be an attrition scrubber (col. 13, lines 51-52).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ an attrition scrubber at the ball mill step, as taught by Dreschel for use with the process of Nie and Rissanen because Dreschel shows that this stream can be later ball-milled after processing through an attrition scrubbing device (see Fig. 5).
Claim(s) 5, 7, 8, 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nie and Rissanen as applied to claims 1 or 4 above, and further in view of El-Shall “Comparative analysis of dolomite/francolite flotation techniques”.
The references do not teach adjusting the pH of the process to 2-4.5.
El-Shall describes a method of processing phosphate rock (Introduction, line 1). In their process, El-Shall describes a first step that includes a first step of milling, followed by screening (see Fig. 1, steps 1 and 2), followed by desliming (Fig. 1) (this is another sieving step). El-Shall describes multiple process steps used to isolate, separate and purifying various factions from the ore (see Fig. 1, 2 and 3). In Fig. 3, El-Shall explains that in the faction separated from Fig. 2, this faction is treated with sulfuric acid (it contains apatite, dolomite and fine quartz, see Fig. 3). This stream is treated so adjust the pH to 3-5 (fig. 3) in order to yield a final phosphate concentration and to a separated amine tailing (pg 138, left col. para. 1).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adjust the pH of the slurry to 3-5, as taught by El-Shall for use with the process of Nie and Rissanen because this facilitates separation of phosphate from the other components of a dolomite, quartz and apatite-containing solution.
As to Claim 7, the references do not describe a second screening and separating the ore that passes through the second screening.
El-Shall describes a method of processing phosphate rock (Introduction, line 1). In their process, El-Shall describes a first step that includes a first step of milling, followed by screening (see Fig. 1, steps 1 and 2), followed by desliming (Fig. 1) (this is another sieving step). The desliming step removes dolomite from the phosphate and a silica removal step (pg 137, left col, lines 4-9). The desliming step separates the feed between a 28 x 150 mesh from the 35 x150 mesh feed (pg 137, left col, lines 31) takes the particles separated in the desliming step that has a size of 28 x 150 mesh is then processed by attrition scrubbing and then further deslimed (screened) again using another screen (pg 137, left col, lines 33-35). After this step, the mixture is then treated with sulfuric acid (see Fig. 4, “conditioning”).
The other fraction, the 35 x 150 mesh separated in the sieve on pg. 137, lines 5-7 is described in Fig. 3. This second fraction, is treated under acid “see Fig. 3, “recondition”, followed by froth flotation (Fig. 3, “frother”). This separates fine silica from dolomite to yield phosphate concentrate and a siliceous amine tailing (pg 138, left col, lines 7, 9-11).
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 screening step and then separate the coarser material from the finer particles and process them, as taught by El-Shall for use with the phosphate ore of Nie and Rissanen because these steps are known to facilitate purification of compounds from the others in the ore mixture.
As to Claim 12, El-Shall teaches that the flotation cell (which is previously screened again, see the rejection to claim 7 incorporated here by reference) yields a final phosphate concentrate (pg 138, left col, para. 1). This phosphate concentration is analyzed to be about 28.2% (pg. 138, left col, para. 2). This can be considered a high-grade size fraction.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to screen the separated faction, as taught by El-Shall for use in the ore purification of Nie and Rissanen because this process further purifies the ore to produce a high phosphate-containing product.
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nie and Rissanen and El-Shall as applied to claim 5 above, and further in view of Cao (CN 105562213).
The references do not teach that mixing is performed until one of the stop conditions of Claim 6 is reached.
Cao describes a method of treating phosphorus ore (abstract). The process first crushes the ore (abstract) and then treats the ore with sulfuric acid (abstract). Cao explains that the mixture can be stirred for 5 to 40 minutes (see pg 2, step. 4, para. 2) as a method of separating the phosphorite (pg. 2, para. 1, 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to mix the slurry for a certain preset amount of time, as taught by Cao for use with the process of Nie and Rissanen and El-Shall because this amount of time is taught in the prior art to be effective for blending a phosphate-ore with sulfuric acid.
Claim(s) 9, 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nie and Rissanen as applied to claim 4 above, and in view of El-Shall and further in view of Phillips (US Pat.: 4238459).
The references do not describe the features of Claim 9.
El-Shall a method of processing phosphate rock (Introduction, line 1). In their process, El-Shall describes a first step that includes a first step of milling, followed by screening (see Fig. 1, steps 1 and 2), followed by desliming (Fig. 1) (this is another sieving step). The process describes in Fig. 3 shows that dolomite, apatite and quartz are mixed together (see Fig. 3).
The reference describes separating dolomite being separated from apatite (see Fig. 3, step “Dolo Flotation” that separates dolomite from apatite), but this reference does not teach adjusting the pH so that it does not cause apatite to dissolve.
Phillips describes a method of selectively extracting calcite and dolomite away from apatite in phosphate rock (abstract). The reference explains that selective extraction of dolomite from apatite is difficult (col. 11, lines 1-5). To do this, Phillips explains that the pH of the solution is controlled so that apatite is not dissolved (col. 8, lines 29-33, col. 9, lines 7-11), but other compounds, such as calcite, are removed (col. 9, line 30-32). Phillips proposes changing the acid in this step from sulfuric to another acid to facilitate adjusting the pH (col. 8, lines 17-32), such as SO2 (col. 8, lines 28-32).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adjust the pH of the solution using a weaker acid, such as SO2, in place of sulfuric acid in this step, in order to avoid dissolution of apatite from dolomite, as taught by Phillips, for use with the process of isolating dolomite from phosphate ore, as taught by El-Shall for use with the process of Nie and Rissanen because Phillips explains that phosphate-containing ores typically contain these mineral factions, whose separation is desirable.
As to Claim 10, Phillips explains that the pH of the solution is controlled by adjusting the rate at which SO2 is added to the system (col. 8, lines 28-24). In examples, Phillips teaches that SO2 added to the reaction mixture can be for 2.7 hrs (example 1), or for a set time.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to mix the slurry in weak acid for 2.7 hrs, as taught by Phillips for use in the process of Nie and Rissanen because this is a known and effective amount of time for separating phosphate from these slurries.
Claim(s) 27 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nie and Rissanen 20 as applied to claim above, and further in view of Snow (US Pat.: 3259242).
Nie describes a method of processing a phosphorous-containing ore (title). In one example, the raw calcium-phosphate ore is crushed and ball milled and ground to a size of 0.074mm (para. 8 of translation). To this slurry, sulfuric acid is added (para. 9), followed by use of a floatation step used to separate apatite and carbonate from phosphate (para. 12). Nie does not describe using a sieve to perform this step.
Snow teaches that froth floatation of apatite and calcite ores is known in the field (title and pg 1, left col, para. 1) and that separation of phosphate from these is highly beneficial (pg 1, left col, lines 37-43). To do this, Snow explains that micro-crystalline apatite values may be substantially liberated from calcite and silicate mineral gangues by use of a mesh amenable to froth floatation operations (pg 1, right col, lines 50-55). To do this, meshes with a sizes of about 325 mesh may be employed (pg 1, right col, lines 58-60).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to add a separating sieve, as taught by Snow to the froth flotation step of Nie because Snow explains that this effectively separates micro-crystalline apatite from the slurry mixture.
Since the pH is adjust to the desired level using acid, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that this can be considered “maintaining the pH level in the slurry to a pH range”, while mixing the slurry.
Example 1 of Snow describes milling, followed by screening, conditioning, followed by treating the ore in a froth floation (see example 1). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to condition the slurry prior to floatation, as taught by Snow for use with Nie and Rissanen because conditioning facilitates removal of unwanted byproduct in the slurry.
Claim(s) 21, 23, 24 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nie and Rissanen as applied to claim 20 above, and in view of Snow and further in view of El-Shall “Comparative analysis of dolomite/francolite flotation techniques”.
The references do not describe the features of Claims 21, 23 and 24.
Snow teaches that froth floatation of apatite and calcite ores is known in the field (title and pg 1, left col, para. 1) and that separation of phosphate from these is highly beneficial (pg 1, left col, lines 37-43). To do this, Snow explains that micro-crystalline apatite values may be substantially liberated from calcite and silicate mineral gangues by use of a mesh amenable to froth floatation operations (pg 1, right col, lines 50-55). To do this, meshes with a sizes of about 325 mesh may be employed (pg 1, right col, lines 58-60).
Snow explains that in the ball milling, sieving and sulfuric acid treatment (see col. 5, left col, line 67) that apatite is separated from BPL (phosphate), calcite, dolomite, micro and other compounds (see example 1, list of percentages of organics and col. 8, lines 35-40).
The references do not teach adjusting the pH of the process to 2-4.5.
El-Shall describes a method of processing phosphate rock (Introduction, line 1). In their process, El-Shall describes a first step that includes a first step of milling, followed by screening (see Fig. 1, steps 1 and 2), followed by desliming (Fig. 1) (this is another sieving step). El-Shall describes multiple process steps used to isolate, separate and purifying various factions from the ore (see Fig. 1, 2 and 3). In Fig. 3, El-Shall explains that in the faction separated from Fig. 2, this faction is treated with sulfuric acid (it contains apatite, dolomite and fine quartz, see Fig. 3). This stream is treated so adjust the pH to 3-5 (fig. 3) in order to yield a final phosphate concentration and to a separated amine tailing (pg 138, left col. para. 1).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adjust the pH of the slurry to 3-5, as taught by El-Shall for use with the process of Nie and Rissanen and Snow because this facilitates separation of phosphate from the other components of a dolomite, quartz-containing solution.
As to Claims 23 and 24, Snow teaches the second screening (see the rejection to Claim 20 above). Snow applies another screen step to the floatation step (see above).
Claim(s) 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nie, Snow and El-Shall as applied to claim 21 above, and further in view of Cao (CN 105562213).
The references do not teach that mixing is performed until one of the stop conditions of Claim 22 is reached.
Cao describes a method of treating phosphorus ore (abstract). The process first crushes the ore (abstract) and then treats the ore with sulfuric acid (abstract). Cao explains that the mixture can be stirred for 5 to 40 minutes (see pg 2, step. 4, para. 2) as a method of separating the phosphorite (pg. 2, para. 1, 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to mix the slurry for a certain preset amount of time, as taught by Cao for use with the process of Nie, Snow and El-Shall because this amount of time is taught in the prior art to be effective for blending a phosphate-ore with sulfuric acid.
Claim(s) 25, 22, 26 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nie, Rissanen, Snow and El-Shall as applied to claim 21 above, further in view of Phillips (US Pat.: 4238459).
The references do not describe the features of Claim 25.
El-Shall a method of processing phosphate rock (Introduction, line 1). In their process, El-Shall describes a first step that includes a first step of milling, followed by screening (see Fig. 1, steps 1 and 2), followed by desliming (Fig. 1) (this is another sieving step). The process describes in Fig. 3 shows that dolomite, apatite and quartz are mixed together (see Fig. 3).
The reference describes separating dolomite being separated from apatite (see Fig. 3, step “Dolo Floation” that separates dolomite from apatite), but this reference does not teach adjusting the pH so that it does not cause apatite to dissolve.
Phillips describes a method of selectively extracting calcite and dolomite away from apatite in phosphate rock (abstract). The reference explains that selective extraction of dolomite from apatite is difficult (col. 11, lines 1-5). To do this, Phillips explains that the pH of the solution is controlled so that apatite is not dissolved (col. 8, lines 29-33, col. 9, lines 7-11), but other compounds, such as calcite, are removed (col. 9, line 30-32). Phillips proposes changing the acid in this step from sulfuric to another acid to facilitate adjusting the pH (col. 8, lines 17-32), such as SO2 (col. 8, lines 28-32).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to adjust the pH of the solution using a weaker acid, such as SO2, in place of sulfuric acid in this step, in order to avoid dissolution of apatite from dolomite, as taught by Phillips, for use with the process of isolating dolomite from phosphate ore, as taught by El-Shall for use with the process of Nie, Rissanen, Snow and El-Shall because Phillips explains that phosphate-containing ores typically contain these mineral factions, whose separation is desirable.
As to Claim 26, Phillips explains that the pH of the solution is controlled by adjusting the rate at which SO2 is added to the system (col. 8, lines 28-24). In examples, Phillips teaches that SO2 added to the reaction mixture can be for 2.7 hrs (example 1), or for a set time.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to mix the slurry in weak acid for 2.7 hrs, as taught by Phillips for use in the process of Nie, Rissanen, Snow and El-Shall because this is a known and effective amount of time for separating phosphate from these slurries.
Conclusion
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHENG HAN DAVIS whose telephone number is (571)270-5823. The examiner can normally be reached 9-5:30.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Fung Coris can be reached at 571-270-5713. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
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