Effluent concentrators, systems, and methods

Abstract

Apparatuses that may be used for flotation processes, including flotation processes that include contacting a stream and a flocculant. Systems that include an apparatuses and one or more other dewatering apparatuses, such as a screen bowl centrifuge and solid bowl centrifuge arranged upstream and downstream, respectively, of the apparatus. Methods for recovering solids from streams.

Description

EFFLUENT CONCENTRATORS, SYSTEMS, AND METHODSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 557,843, filed February 26, 2024, which is incorporated by reference herein.BACKGROUND

[0002] Fine and ultrafine coal recovery has received increased interest for a number of reasons, including the increasing presence of fine and ultrafine coal in preparation plants. The increased percentage of fine coal is likely a result of increased mechanization of mining operations and increased handling intensity. Also, as higher quality coal reserves are depleted, the amount of extraneous rock required to be mined with the coal has significantly increased. More rock in run-of-mine coal likely results in more coal degradation during transit due to transportation attrition. In addition, with increased rock, mine operators typically move to tighter bit spacing on equipment, which means the average particle size of the coarse coal produced decreases. For at least these reasons, there has been a significant increase in the amount of fine coal reporting to typical coal preparation plants for cleaning and recovery'.

[0003] Numerous circuits for fine coal cleaning have been installed. These include spirals, rougher-cleaner spirals, water-washing cyclones, reflux classifiers, heavy media cyclones, teeter bed systems, 0.5 mm x 0 flotation, split flotation, and column flotation. There have even been rougher-cleaner flotation circuits and combined circuits, such as water washing cyclone / spirals circuit and fine spirals combined with flotation to aid in sulfur removal. These circuits have varying degrees of success, depending on a number of factors, such as site-specific conditions and quality parameters.

[0004] Changes in fine coal recovery / dewatering circuits have led to increased fine coal generation and losses. Previously used vacuum filter circuits have been widely replaced with screen bowl circuits. Vacuum filter circuits offered high recovery, typically >95%, but were costly, primarily regarding manpower and maintenance. Screen bowl circuits are ty pically more durable and less manpower intensive, but usually discard a large amount (such as about 50 %) of the minus 325 mesh solids in a feed, and screen bow l recovery' typically ranges from 80 % to 90 % (see, e.g., Luttrell, G. et al. 2006, “Improving Screen-Bowl Performance, ” SME Annual Meeting. St. Louis, MO. preprint 06-010). In high clay circuits,the selective rejection of minus 325 mesh material typically is beneficial. Furthermore, the screen drain stream from a screen bowl centrifuge usually is recycled.

[0005] This recycle stream may be of higher tonnage than show n on flow sheets, can contribute to fines circuit overloading, and may be only partially recovered (see, e.g., Toney, T. et al. 2020, "Screen Bowl Insurance, Direct Recovery v. Indirect Recovery via Recycle,” CPS A Journal, 19(1)). Screen drain recycle also can increase degradation in an overloaded fines circuit. The screen drain is typically about 10 % of the screen bowl feed, and averages about 20 % to 40 % solids w / w. These values can increase as a screen bowl wears.

[0006] Solid bowl centrifuges have been used to reduce greatly the screen drain recycle stream. The screen drain material typically reports to a solid bowl centrifuge, and then to a product belt. The recycle elimination has been shown to free up capacity in the fine coal circuits. This usually makes the fines circuit more efficient for recovery of new coal. It also can reduce fine coal degradation by eliminating recycling.

[0007] A bowl effluent stream is typically sent to a thickener for disposal. It is generally 95 wt% minus 44-micron material and is about 2 % to about 6 % solids w / w. However, in many metallurgical coal plants, this tonnage is significant, and the material is clean enough to have value as a source of fine carbon.

[0008] The screen bowl effluent material, such as an effluent material from a 400 G- force screen bowl centrifuge, can be recovered in a solid bowl centrifuge, such as a 1,200 G- force centrifuge. However, the screen bowl effluent material is typically too diluted for direct feed. At 5 wt% solids, for example, the volumetric capacity of a solid bowl centrifuge would be exceeded long before the tonnage capacity is met. Efficiency w ould be undesirably impacted by the number of machines that would be needed to handle the volume of screen bowl effluent.

[0009] There remains a need for methods and apparatuses for thickening feeds, especially prior to processing the feeds with a solid bowl centrifuge or other dewatenng device.BRIEF SUMMARY

[0010] Described herein are methods and apparatuses for thickening a stream, such as via “flocculant flotation"’ or “floc flotation”. The phrases “flocculant flotation"’, “floc flotation”, and the like, as used herein, refer to and include methods in which flocculants, such as polymer flocculants, are used to selectively aggregate particles of the same mineral species, such as metallurgical coal particles, thereby permitting their subsequent collectionusing methods, such as those provided herein. In some embodiments, the apparatuses and methods described herein are particularly suited for collecting ultrafme particles in the sub-44 micron size range.

[0011] In one aspect, apparatuses are provided. In some embodiments, the apparatuses include a reservoir defined at least in part by a bottom surface, wherein a portion of the bottom surface is upwardly inclined, thereby imparting a depth gradient to the reservoir; an inlet configured to receive a feed; a first outlet configured to discharge a first product stream from the apparatus; a second outlet configured to discharge a second product stream from the apparatus; and a conveyor, wherein the conveyor is configured to transport the first product stream to the first outlet. The feed may include a liquid and a plurality of solids dispersed in the liquid, wherein the plurality of solids is present at an initial concentration. The first product stream may include solids at a concentration greater than the initial concentration. The second product stream may include an effluent. In some embodiments, the reservoir is defined at least in part by the bottom surface, a first side wall, a second side wall, and a rear wall. A bottom surface may have a terminal edge opposite the rear wall, and the conveyor may be configured to transport a product stream, such as a first product stream, from a position in the reservoir to a position beyond the terminal edge of the bottom surface.

[0012] In another aspect, methods are provided. In some embodiments, the methods include providing a first stream that includes a liquid and a plurality of solids dispersed in the liquid, wherein the plurality of solids is present at a first concentration; contacting the first stream and a flocculant at an amount and for a time effective to form in the first stream a first area having an increased concentration of the plurality of solids relative to the first concentration, and a second area having a decreased concentration of the plurality of solids relative to the first concentration; and separating the first area and the second area to form a second stream comprising the first area, and, optionally, a third stream comprising the second area. The methods may be performed using any of the apparatuses provided herein, or other apparatuses.

[0013] Additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the aspects described herein, or derived from targeted research work. The advantages described herein may be realized and attained by means of the elements and combinations particularly pointed out in the appended embodiments and claims. It is to be understood that both the foregoinggeneral description and the following detailed description are exemplary and explanatory' only and are not restrictive.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1A depicts a side view of an embodiment of an apparatus provided herein.

[0015] FIG. IB depicts a front view of the embodiment of the apparatus depicted at FIG. 1A

[0016] FIG. 1C depicts a rear view of the embodiment of the apparatus depicted at FIG. 1A and FIG. IB

[0017] FIG. ID depicts a cross-sectional view of the embodiment of the apparatus depicted at FIG. 1A, FIG. IB, and FIG. 1C

[0018] FIG. 2 depicts an embodiment system that includes an embodiment of an apparatus described herein, and a screen bowl centrifuge and a solid bowl centrifuge arranged upstream and downstream, respectively, of the apparatus.DETAILED DESCRIPTION

[0019] Provided herein are apparatuses, systems, and methods for processing streams that include solids dispersed in a liquid.

[0020] Apparatuses

[0021] The apparatuses provided herein may include a reservoir, an inlet configured to receive a feed, a first outlet configured to discharge a first product stream from the apparatus, a second outlet configured to discharge a second product stream from the apparatus, and a conveyor. The apparatus may be a gravimetric apparatus, or, in other words, an apparatus that relies only on the force of gravity’ to make a separation. The feed may include a liquid and a plurality of solids dispersed in the liquid, wherein the plurality of solids is present at an initial concentration. The first product stream may' include at least a portion of the plurality' of solids. The first product stream may be a stream that includes solids at a concentration greater than the initial concentration. For example, a concentration of solids in a first product stream may be greater than 10 %, greater than 20 %. greater than 30 %, greater than 40 %, greater than 50 %, greater than 60 %, greater than 70 %, greater than 80 %, or greater than 90 %, by weight, based on the weight of the first product stream. The second product stream may include an effluent.

[0022] The apparatuses provided herein may produce two or more products. The two or more products may include sludge concentrate, an effluent, froth concentrate, or a combination thereof. In some embodiments, the apparatuses include a first outlet configured to discharge a first product stream from the apparatus, and the first product stream includes sludge concentrate. In some embodiments, the apparatuses include a second outlet configured to discharge a second product stream from the apparatus, and the second product stream includes an effluent, froth concentrate, or a combination thereof.

[0023] The feed may be obtained from any source or process. The feed, for example, may include a tailings stream (e.g., flotation tailings), an effluent stream (e.g., sieve effluent, screen effluent, screen bowl effluent, etc.), an overflow stream (e.g., classifying cyclone overflow, thickener overflow, clarifier overflow, etc.), etc.

[0024] Reservoirs

[0025] The reservoirs of the apparatuses provided herein generally may have any shape and / or size. In some embodiments, a reservoir is defined at least in part by a bottom surface. The bottom surface may include a portion that is upwardly inclined. The upwardly inclined portion of the bottom surface may impart a depth gradient to the reservoir. The depth of a reservoir, for example, may decrease continually or intermittently at positions approaching a terminal edge of a bottom surface.

[0026] A reservoir may be defined at least in part by a bottom surface, a first side wall, a second side wall, and a rear wall. Any two or more of the components that define a reservoir may be monolithic or modular.

[0027] A bottom surface may have a terminal edge opposite a rear wall. A conveyor or other device may be configured to transport solids and / or liquids from a position in the reservoir to a position beyond the terminal edge. For example, a conveyor may transport solids of a first product stream along a portion of a bottom surface towards, and then beyond, a terminal edge of the bottom surface. When the solids of a first product stream are transported beyond the terminal edge, the solids (and other components of the first product stream), via gravi ty, may be discharged via an outlet of the apparatus.

[0028] A bottom surface may include one or more flat portions, one or more curved portions, or a combination thereof. The upward incline of a bottom surface may be provided in any manner, such as by a curved portion of the bottom surface, or two or more flat portions connected to each other at angles that impart the upward incline.

[0029] In some embodiments, a bottom surface includes a first substantially flat portion extending from the rear wall. The first substantially flat portion of the bottom surfacemay be substantially parallel to a surface on which the apparatus is disposed. Therefore, the first substantially flat portion of the bottom surface may impart the reservoir with a zone having a static depth throughout the zone.

[0030] In some embodiments, the bottom surface includes an upwardly curved portion extending from the first substantially flat portion. Therefore, the first substantially flat portion may be arranged between the rear wall and the upwardly curved portion. The upwardly curved portion may impart a depth gradient to the reservoir. In some embodiments, the upwardly curved portion includes the terminal edge of the bottom surface.

[0031] In some embodiments, the bottom surface includes a second substantially flat portion extending from the upwardly curved portion. Therefore, the upwardly curv ed portion may be arranged between the first and the second substantially flat portions. The second substantially flat portion may include the terminal edge of the bottom surface.

[0032] A bottom surface generally may incline upwardly at any angle. For example, when a bottom surface includes a second substantially flat portion, an angle between the second substantially flat portion and a surface on which the apparatus is disposed may be about 15 ° to about 45 °. about 20 ° to about 40 about 25 ° to about 35 °, or about 30 °.

[0033] A bottom surface also may include one or more other features. For example, a bottom surface may include a downwardly inclined portion that extends from the rear wall, and is arranged between the rear w all and the first substantially flat portion or the upwardly- curved portion. The downwardly inclined portion may increase the likelihood that settling solids are contactable by a conveyor.

[0034] Conveyors

[0035] The apparatuses herein may include a conveyor. The conveyor may be any that is capable of transporting solids and / or liquids within and / or out of the apparatus, particularly the reservoir. In some embodiments, the conveyor is a chain conveyor. The chain conveyor may include a sprocket, a chain, and a paddle. As known in the art, one or more sprockets may engage a chain so that the turning of the one or more sprockets cycles the chain and one or more paddles that are affixed to the chain.

[0036] The conveyor may include at least three, at least four, at least five, at least six, or at least seven sprockets, or at least three, at least four, at least five, at least six, or at least seven pairs of sprockets. When pairs of sprockets are present, the conveyor may include two chains, and each of the one or more paddles may be affixed to both chains. The chains may be affixed to terminal positions of each paddle, or other positions of the paddles.

[0037] A conveyor generally may include any number of paddles. A conveyor, for example, may include at least one paddle per X meters of a chain, wherein X is about 0.05 to about 2, about 0.05 to about 1.5, about 0.05 to about 1, about 0.1 to about 1, or about 0.1 to about 0.5.

[0038] A conveyor may be configured to transport solids and / or liquids along at least a portion of a bottom surface of a reservoir. For example, a paddle may contact at least a portion of the bottom surface during a portion of each cycle of a chain. As a further example, a conveyor may be configured to maintain a minimum distance between the one or more paddles and a bottom surface, such as about 0.01 cm to 1 cm. A conveyor may transport solids and / or liquids, e.g., a concentrated material (such as a sludge concentrate), along the top of a fluid in the reservoir, e.g.. a flotation product.

[0039] Additionally or alternatively, a conveyor may be configured to function as a skimmer, which may remove a product, such as a froth concentrate, from an area at or near a surface of a liquid in a reservoir.

[0040] A settling rate of solids may be impacted by one or more factors, such as particle size. Typically, solids having smaller particle sizes settle more slowly than solids having larger particle sizes. Although settling — and, therefore, the separation — of solids may be positively impacted by the relative densities of the solids, the settling may be adversely impacted by other factors, such as the buoyancy of the solids, liquid density, liquid viscosity, particle-to-particle interactions, or a combination thereof. In some embodiments, the apparatuses provided herein include one or more lamella plates. The one or more lamella plates may decrease the time required for settling, and / or promote the concentration of solids, such as the concentration of solids in the first area. For example, the one or more lamella plates can provide a sliding surface, and may limit the distance a solid settles through a counter current flow of liquid and / or other solids. Other techniques may be used to improve selectivity and / or recover}7in any of the apparatuses, systems, and methods described herein, such as ultrasound, froth sprinkling, etc. Ultrasonic vibration, for example, may be used to modify, e.g., accelerate, the settling rate of one or more types of solids.

[0041] An embodiment of an apparatus provided herein is depicted at FIG. 1A (side view), FIG. IB (front view), FIG. 1C (rear view), and FIG. ID (cross-section). The apparatus 100 includes an inlet 120 that is configured to receive a feed, such as any of the streams described herein. The apparatus 100 includes an outlet 130 that is configured for discharging concentrate, which includes solids, from the reservoir 110. The apparatus 100 includes an outlet 140 that is configured for discharging effluent from the reservoir 110. Theapparatus 100 also includes a drain 141. The apparatus 100 includes a reservoir 110 that is defined by side walls 111, a rear wall 112. and a bottom surface 113. The bottom surface 113 includes a flat portion 114 extending from the rear wall 112. The bottom surface 113 also includes an upwardly curved portion 115 extending from the flat portion 114, and a flat portion 116 extending from the upwardly curved portion 115. An angle between the two flat portions 114.116 is 30 ° in the embodiment of FIG. 1A — FIG. ID. but other angles are envisioned as described herein. The bottom surface 113 has a terminal edge 117 opposite the rear wall 112. The apparatus 100 also includes a plurality of lamella plates 160 in the reservoir 110. The apparatus 100 also includes a conveyor 150. The conveyor 150 of the embodiment depicted at FIG. 1A — FIG. ID includes six pairs of sprockets 151, two chains 152, and a series of paddles 153 connected to. and arranged between, the two chains 152. The series of paddles 153 are configured, in this embodiment, to (i) transport solids, such as solids of a first product stream, along the bottom surface 113 and beyond the terminal edge 117 of the bottom surface 113, thereby transporting the solids, via gravity, to the outlet 130, and / or (ii) transport a concentrated material along the top of the fluid in the reservoir.

[0042] Systems

[0043] Also provided herein are systems. The systems may include any of the apparatuses described herein. In some embodiments, the systems include an apparatus, as described herein, and at least one dewatering apparatus, wherein the at least one dewatering apparatus is arranged upstream of the apparatus or downstream of the apparatus. In some embodiments, a first dewatering apparatus is upstream of the apparatus, and a second dewatering apparatus is dow nstream of the apparatus.

[0044] The at least one dewatering apparatus may include, for example, a centrifuge (e.g., a solid bowl centrifuge or a screen bowl centrifuge), a belt filter press, a plate press, a horizontal belt vacuum filter, a rotary vacuum drum, a rotary vacuum disc filter, a thickener (e.g., a deep cone / paste thickener), a membrane pressure filter, etc. The components of the systems may be in fluid communication.

[0045] In some embodiments, the systems include an apparatus, as described herein, and a screen bowl centrifuge. The screen bowl centrifuge may be arranged upstream of the apparatus. The systems also may include a solid bowl centrifuge, which may be in fluid communication with the apparatus, and the apparatus may be upstream of the solid bowl centrifuge.

[0046] An embodiment of a system is depicted at FIG. 2. The system 200 of FIG. 2 includes a screen bowl centrifuge 210, an apparatus 100 of FIG. 1A — FIG. ID, and a solidbowl centrifuge 240, which are in fluid communication. The screen bowl centrifuge 210 mayproduce an effluent 220 that is disposed in the apparatus 100 of FIG. 1A — FIG. ID. which is arranged downstream of the screen bowl centrifuge 210. The apparatus 100 may produce a first product stream (or “second stream”) 230, which is disposed in a solid bowl centrifuge 240. The solid bowl centrifuge 240 is arranged downstream of the apparatus 100.

[0047] Methods

[0048] Also provided herein are methods of processing materials, such as streams that include a liquid and a plurality7of solids dispersed in the liquid.

[0049] In some embodiments, the methods include providing a first stream that includes a liquid and a plurality of solids dispersed in the liquid, wherein the plurality- of solids is present at a first concentration; and contacting the first stream and a flocculant at an amount and for a time effective to form in the first stream a first area having an increased concentration of the plurality- of solids relative to the first concentration, and a second area having a decreased concentration of the plurality- of solids relative to the first concentration. For example, when at least a majority of the solids settle to an area at or near a bottom of reservoir, the area at or near the bottom of the reservoir may be the first area of the first stream, because the settling increases the concentration of solids at or near the bottom of the reservoir.

[0050] The methods also may include separating the first area and the second area to form a second stream that includes the first area of the first stream, and, optionally, a third stream that includes the second area of the first stream. The first area and the second stream may include sludge concentrate. The second area and the third stream may include an effluent, froth concentrate, or a combination thereof.

[0051] The contacting of a first stream and a flocculant may occur in any manner. A flocculant, for example, may be transported and / or dispensed using any known equipment or technique. The equipment and / or technique used may be selected based on the type and character of a first stream. A flocculant, for example, may be dispersed, such as by spraying or otherwise.

[0052] Any of the methods described herein may be performed, at least in part, with any of the apparatuses described herein. For example, the methods may include providing an apparatus described herein; providing a first stream that includes a liquid and a plurality- of solids dispersed in the liquid, wherein the plurality- of solids is present at a first concentration; disposing the first stream in the reservoir of the apparatus via the inlet; contacting the first stream and a flocculant at an amount and for a time effective to form in the first stream a firstarea having an increased concentration of the plurality of solids relative to the first concentration, and a second area having a decreased concentration of the plurality of solids relative to the first concentration, wherein the contacting of the first stream and the flocculant occurs before and / or after the disposing of the first stream in the apparatus; and separating the first area and the second area with a skimming apparatus or the conveyor to form a second stream that includes the first area of the first stream, and, optionally, a third stream that includes the second area of the first stream. The first area and the second stream may include sludge concentrate. The second area and the third stream may include an effluent, froth concentrate, or a combination thereof.

[0053] The methods also may include subjecting the second stream to further processing. For example, the second stream may be disposed in a dewatering apparatus, such as a solid bowl centrifuge, a belt filter press, a plate press, a horizontal belt vacuum filter, a rotary vacuum drum, a rotary vacuum disc filter, a thickener (e.g., a deep cone / paste thickener), a membrane pressure filter, etc.

[0054] The methods may also include contacting the first stream and one or more lamella plates, subjecting the first stream to ultrasonic vibration, or a combination thereof.

[0055] Densities

[0056] A density differential or an apparent density7differential may exist between a liquid and a plurality of solids. A density of the plurality of solids may be greater than a density of the liquid. In this scenario, a first area of a first stream, which has an increased concentration of the plurality7of solids may be (or may form) below the second area having the decreased concentration of the plurality of solids. An apparent density7of the plurality of solids may be less than a density of the liquid. In this scenario, the first area having the increased concentration of the plurality of solids may be (or may form) above the second area having the decreased concentration of the plurality of solids.

[0057] First Stream

[0058] The liquid of a first stream may include any liquid. The liquid may be an aqueous liquid. For example, water may be present in the first stream at a concentration of at least 50 %. at least 60 %, at least 70 %, at least 80 %, at least 90 %, or at least 95 %, by weight, based on the weight of the first stream.

[0059] A first stream may be aerated. In some embodiments, the providing of the first stream includes aerating the first stream. The aerating of the first stream may be achieved using any known technique. When a first stream is aerated, the plurality of solids may have an apparent density that is less than the density of the liquid.

[0060] A plurality of solids may be dispersed evenly or unevenly in a liquid. The plurality of solids may be present at any concentration that does not undesirably impact the methods described herein. In some embodiments, the first concentration (or “initial” concentration) of the plurality of solids (e.g., total suspended solids) is about 1 % to about 20 %, about 1 % to about 18 %, about 1 % to about 16 %, about 1 % to about 14 %, about 1 % to about 12 %, about 1 % to about 10 %, about 1 % to about 8 %, about 1 % to about 6 %, about 1 % to about 4 %, about 1 % to about 10 %. about 2 % to about 10 %, about 2 % to about 8 %, or about 2 % to about 6 %, by weight, based on the weight of the first stream (or feed).

[0061] The first stream generally may be obtained from any source or process. The first stream, for example, may be a tailings stream (e.g., flotation tailings), an effluent stream (e.g., sieve effluent, screen effluent, etc.), an overflow stream (e.g.. classifying cyclone overflow, thickener overflow, clarifier overflow, etc.), etc. The first stream may include an effluent stream from any device, such as a dewatering device. The dewatering device may include a centrifuge, for example, a screen bowl centrifuge. Regardless of its source, a first stream may be unmodified prior to being disposed in an apparatus or contacted with a flocculant in the methods described herein. For example, when a first stream includes an effluent, such as an effluent from a screen bowl centrifuge, the first stream may produce a froth concentrate with no air added; in other words, the effluent is unmodified via aeration or otherwise prior to being disposed in an apparatus or contacted with a flocculant.

[0062] First Area / Second Stream

[0063] The first area of a first stream, which has an increased concentration of the plurality of solids comprises, may include a film of solids.

[0064] In some embodiments, a concentration of the plurality of solids in the second stream is about 5 % to about 40 %, about 10 % to about 40 %, about 12 % to about 40 %, about 14 % to about 40 %, about 16 % to about 40 %, about 18 % to about 40 %, about 20 % to about 40 %, about 10 % to about 24 %, about 12 % to about 22 %, about 12 % to about 20 %, or about 14 % to about 20 %, by weight, based on the weight of the second stream.

[0065] In some embodiments, a concentration of the plurality of solids in the second stream is about 2X to about 8X, about 2X to about 6X, about 2X to about 5X, or about 3X to about 5X, wherein X is the first concentration of the plurality of solids in the first stream. For example, if the first concentration is 5 %, and the concentration of the plurality of solids in the second stream is 3X, then 15 % is the concentration of solids in the second stream.

[0066] The first area and the second stream may include sludge concentrate.

[0067] Second Area ' Third Stream

[0068] A second area of a first stream, which has a decreased concentration of the plurality of solids, may include clarified water. The clarified water may be used in any manner. In some embodiments, a concentration of the plurality of solids in the third stream is about 0.1 % to about 5 %, about 0.1 % to about 4 %, about 0. 1 % to about 3 %, about 0.1 % to about 2 %, about 0.5 % to about 2 %, by weight, based on the weight of the third stream.

[0069] The second area and the third stream may include an effluent, froth concentrate, or a combination thereof.

[0070] Separating the First Area and the Second Area

[0071] A first area and a second area of a first stream may be separated using any effective or known technique. In some embodiments, the separating of the first area and the second area includes contacting the first area or the second area with a conveyor, as described herein, or a skimming apparatus. Due to the nature of the methods described herein, and flotation methods generally, a first area and a second area may not be amenable to a precise separation. Therefore, for purposes of this disclosure, a first area and a second area are considered separated when a second stream formed of a first area has a greater concentration of solids than the first stream.

[0072] Solids

[0073] The plurality of solids generally may include any type of solids that may be suspended in a liquid. In some embodiments, the plurality of solids includes hydrophobic solids, such as hydrophobic minerals. The solids, for example, may be hydrophobic due to their natural character or modified, in any manner, to increase their hydrophobic character, such as by including one or more hydrophobic moi eties. The plurality' of solids may include coal. The plurality of solids may include an ore, such as an industrial / metalliferous ore (e.g., iron ore) or phosphate ore. one or more platinum group metals (PGMs), or a combination thereof. In some embodiments, the plurality- of solids includes a phosphorus-containing compound. The phosphorus-containing compound may include phosphate, a phosphorus oxide, or combination thereof. For example, the phosphorus-containing compound may include bone phosphate of lime, phosphorus pentoxide, etc. The phrase "bone phosphate of lime’7is a well-known term of art, which is generally understood to refer to and include tricalcium phosphate (TCP) (CasCPCfity) (which is commonly known as “calcium phosphate"). Therefore, the phrase “bone phosphate of lime” may refer to and include carbonateapatite [3Ca3(PC>4)2 -CaCOs], fluorapatite [3Ca3(PC>4)2 -CaF2], hydroxyapatite [3Cas(PO4)2 -Ca(OH)2], sulphoapatite [3Ca3(PO4)2 -CaSCfi], or a heterogeneous residual mixture thereof. In some embodiments, the plurality of solids includes one or more metals.one or more metal-containing compounds, or one or more minerals. The metals may include one or more platinum group metals (PGM), such as “4e PGM?’ (platinum, palladium, rhodium, and gold), or 6e PGM (platinum, palladium, rhodium, ruthenium, osmium, and iridium). The metal may include ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, iron, or a combination thereof. The metal-containing compound may include a metal oxide, a metal carbonate, or a combination thereof. The metal oxide may include iron oxide. The mineral may include gypsum.

[0074] The solids generally may be of any shape and / or size, but, in some embodiments, at least 80 %, at least 85 %, at least 90 %, at least 95 %, by weight, of the plurality of solids is not retainable by a 325 mesh sieve (US standard sieve), i.e., sub-44 micrometers.

[0075] Flocculants

[0076] In some embodiments, the flocculant is a non-ionic flocculant. In some embodiments, the flocculant is an anionic flocculant. In some embodiments, the flocculant is a cationic flocculant. In some embodiments, the flocculant is a fatty acid / lipid flocculant. In some embodiments, the flocculant is a polymeric flocculant, which includes a polymer, such as an acrylic polymer (e.g., a polyacrylamide), a polysaccharide (e.g., chitosan), poly (diallyl dimethyl-ammonium chloride), etc. When the flocculant is a polymeric flocculant, the polymer may be a high molecular weight polymer (i.e., a polymer having an Mw of at least 100,000 g / mol), or a very high molecular weight polymer ( / .e., a polymer having an Mwof at least 10,000,000 g / mol). In some embodiments, the flocculant is a non-ionic polymeric flocculant. In some embodiments, the flocculant is a non-ionic high or very high molecular weight polymeric flocculant. In some embodiments, the flocculant is an anionic polymeric flocculant. In some embodiments, the flocculant is an anionic high or very high molecular weight polymeric flocculant. In some embodiments, the flocculant is a cationic polymeric flocculant. In some embodiments, the flocculant is a cationic high or very high molecular weight polymeric flocculant. In some embodiments, the flocculant is a commercially - available flocculant, such as NALCO™ 749222 flocculant, YONGXING™ YX 1224-6 flocculant, YONGXING™ PAM flocculant, YIXING™ APAM01 flocculant, ULTRACLEAR™ PROFLOCCULANT™ flocculant, GLORY™ flocculant, ZETAG™ 8127 flocculant (BASF, USA), ZETAG™ 4145 flocculant (BASF, USA), MAGNAFLOC® LT20 flocculant (BASF, USA), MAGNAFLOC® 338 flocculant (BASF. USA), MAGNAFLOC® 10 flocculant (BASF, USA), MAGNAFLOC® 155 flocculant (BASF. USA), RHEOMAX® 1050 flocculant (BASF, USA), RHEOMAX® ETD 9010 flocculant(BASF, USA), MAGNAFLOC® LT27AG polyacrylamide flocculant (BASF, USA), ZETAG™ 7109 acrylic homopolymer flocculant (BASF, USA), MAGNAFLOC® 333 flocculant (BASF, USA), FLOBEADS® KB206SH flocculant (SNF, UK), FLOBEADS® KB156 flocculant (SNF, UK), FLOP AM® FO4190 flocculant (SNF, UK), FLOP AM® FO4140 flocculant (SNF, UK), FLOQUAT® TS 45 SH flocculant (SNF, UK), FLOP AM® FA920VHM flocculant (SNF, UK), FLOP AM® FA920VHR flocculant (SNF, UK), FLOP AM® FA920SD flocculant (SNF. UK). FLOP AM® FA920SHD flocculant (SNF. UK), FLOP AM® FA920 flocculant (SNF, UK), ALCLAR® 5000 flocculant (BASF, USA), ALCLAR® 600 flocculant (BASF, USA), ALCLAR® 661 flocculant (BASF, USA), ALCLAR® HP20 flocculant (BASF, USA). ALCLAR® HP21 flocculant (BASF, USA), ALCLAR® HP22 flocculant (BASF, USA). DRIMAX® 1235 flocculant (Allied Colloids Ltd., UK), DRIMAX® 1238 flocculant (Allied Colloids Ltd., UK), DRIMAX® 1240 flocculant (Allied Colloids Ltd., UK), LUPROMIN® F-20X flocculant (BASF, USA), LUPROMIN® FP 18 AS flocculant (BASF, USA), LUPROMIN® FP 199 (BASF, USA), HI-TEX® 82230 flocculant (Hi-Tex Corp, USA), or a combination thereof.

[0077] A flocculant may be in any form prior to its use in the methods provided herein. A flocculant, for example, may be in the form of a powder prior to its use in the methods provided herein. The powder may include a plurality of particles having any shape or size. In some embodiments, less than 2 % of the particles of a powder are retainable with a 20 mesh sieve, a 25 mesh sieve, a 30 mesh sieve, or a 35 mesh sieve (US standard sieve).

[0078] A flocculant, such as a flocculant in the form of a powder, may be combined with a liquid, typically clean water, prior to its use in the methods provided herein. A flocculant may dissolve completely or partially in the liquid. In some embodiments, a flocculant is in the form of a powder, and the powder is combined with clean water to form a combination. A pH of the water may be modified, if necessary or desirable, prior to disposing a flocculant in the water. The selection of a pH that increases the ionic character of a flocculant may permit the use of a lower dose rate of the flocculant. Commercially available flocculants can include liquids in which a flocculant is disposed; therefore, in some embodiments, the methods herein include providing a liquid in which a flocculant powder is disposed.

[0079] A flocculant may be an emulsion, or a component of an emulsion.

[0080] A density of a flocculant also may be adjusted based on the character of a first stream.

[0081] While certain aspects of conventional technologies have been discussed to facilitate disclosure of various embodiments, applicants in no way disclaim these technical aspects, and it is contemplated that the present disclosure may encompass one or more of the conventional technical aspects discussed herein.

[0082] The present disclosure may address one or more of the problems and deficiencies of known methods and processes. However, it is contemplated that various embodiments may prove useful in addressing other problems and deficiencies in a number of technical areas. Therefore, the present disclosure should not necessarily be construed as limited to addressing any of the particular problems or deficiencies discussed herein.

[0083] In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge, or otherwise constitutes prior art under the applicable statutory' provisions; or is known to be relevant to an attempt to solve any problem with which this specification is concerned.

[0084] In the descriptions provided herein, the terms “includes / ’ ‘is,” “containing.” “having,” and “comprises” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to.” When methods, apparatuses, or systems are claimed or described in terms of “comprising” various steps or components, the methods or systems can also “consist essentially of’ or “consist of’ the various steps or components, unless stated otherwise.

[0085] The terms “a,” “an,” and “the” are intended to include plural alternatives, e.g., at least one. For instance, the disclosure of “a liquid,” “a sprocket,” “a chain”, “a paddle”, “a flocculant”, and the like, is meant to encompass one, or mixtures or combinations of more than one liquid, sprocket, chain, paddle, and the like, unless otherwise specified.

[0086] Various numerical ranges may be disclosed herein. When Applicant discloses or claims a range of any type, Applicant’s intent is to disclose or claim individually each possible number that such a range could reasonably encompass, including end points of the range as well as any sub-ranges and combinations of sub-ranges encompassed therein, unless otherwise specified. Moreover, all numerical end points of ranges disclosed herein are approximate. As a representative example, Applicant discloses, in some embodiments, that an angle between a substantially flat portion and a surface on which an apparatus is disposed is about 25 ° to about 35 °. This range should be interpreted as encompassing about 25 ° andabout 35 °, and further encompasses “about"’ each of 26 °, 27 °, 28 °, 29 °, 30 °, 31 °, 32 °, 33 °. and 34 °. including any ranges and sub-ranges between any of these values.

[0087] As used herein, the term “about” means plus or minus 10 % of the numerical value of the number with which it is being used.EMBODIMENTS

[0088] The following is a non-limiting listing of embodiments of the disclosure.

[0089] Apparatuses

[0090] Embodiment 1. An apparatus comprising, consisting essentially of, or consisting of a reservoir, an inlet configured to receive a feed, a first outlet configured to discharge a first product stream from the apparatus, a second outlet configured to discharge a second product stream from the apparatus, and a conveyor.

[0091] Embodiment 2. An apparatus comprising, consisting essentially of, or consisting of a reservoir defined at least in part by a bottom surface, wherein a portion of the bottom surface is upwardly inclined, thereby imparting a depth gradient to the reservoir; an inlet configured to receive a feed; a first outlet configured to discharge solids from the apparatus; a second outlet configured to discharge an effluent from the apparatus; and a conveyor, wherein the conveyor is configured to transport solids to the first outlet.

[0092] Embodiment 3. An apparatus depicted at FIG. 1A, FIG. IB, FIG. 1C, and FIG. ID

[0093] Embodiment 4. The apparatus of any of the preceding embodiments, wherein the apparatus is a gravimetric apparatus (i.e., an apparatus that relies only on the force of gravity to effect a separation).

[0094] Embodiment 5. The apparatus of any of the preceding embodiments, wherein the feed comprises a liquid and a plurality of solids dispersed in the liquid, wherein the plurality7of solids is present in the feed at an initial concentration.

[0095] Embodiment 6. The apparatus of any of the preceding embodiments, wherein the initial concentration of the plurality of solids (e.g., total suspended solids) is about 1 % to about 20 %, about 1 % to about 18 %, about 1 % to about 1 %, about 1 % to about 14 %, about 1 % to about 12 %, about 1 % to about 10 %, about 1 % to about 8 %, about 1 % to about 6 %, about 1 % to about 4 %, about 1 % to about 10 %, about 2 % to about 10 %, about 2 % to about 8 %, or about 2 % to about 6 %, by weight, based on the weight of the feed.

[0096] Embodiment 7. The apparatus of any of the preceding embodiments, wherein the first product stream includes solids at a concentration greater than the initialconcentration; wherein, optionally, the concentration of solids in the first product stream is greater than 10 %, greater than 20 %, greater than 30 %, greater than 40 %. greater than 50 %, greater than 60 %, greater than 70 %, greater than 80 %, or greater than 90 %, by weight, based on the weight of the first product stream.

[0097] Embodiment 8. The apparatus of any of the preceding embodiments, wherein a concentration of solids in the first product stream is about 5 % to about 40 %, about 10 % to about 40 %, about 12 % to about 40 %, about 14 % to about 40 %, about 16 % to about 40 %, about 18 % to about 40 %, about 20 % to about 40 %, about 10 % to about 24 %, about 12 % to about 22 %, about 12 % to about 20 %, or about 14 % to about 20 %, by weight, based on the weight of the first product stream.

[0098] Embodiment 9. The apparatus of any of the preceding embodiments, wherein the second product stream comprises an effluent, froth concentrate, or a combination thereof.

[0099] Reservoirs

[0100] Embodiment 10. The apparatus of any of the preceding embodiments, wherein the reservoir is defined at least in part by a bottom surface, wherein a portion of the bottom surface is upwardly inclined, thereby imparting a depth gradient to the reservoir.

[0101] Embodiment 11. The apparatus of any of the preceding embodiments, wherein the reservoir is defined at least in part by the bottom surface, a first side wall, a second side wall, and a rear wall.

[0102] Embodiment 12. The apparatus of any of the preceding embodiments, wherein the bottom surface has a terminal edge opposite the rear wall, wherein the conveyor is configured to (i) transport the first product stream from a position in the reservoir to a position beyond the terminal edge, (ii) function as a skimmer, which may remove a product, such as a froth concentrate, from an area at or near a surface of a liquid in a reservoir, or (iii) a combination thereof.

[0103] Embodiment 13. The apparatus of any of the preceding embodiments, wherein the bottom surface comprises a first substantially flat portion extending from the rear wall.

[0104] Embodiment 14. The apparatus of any of the preceding embodiments, wherein the first substantially flat portion of the bottom surface is substantially parallel to a surface on which the apparatus is disposed.

[0105] Embodiment 15. The apparatus of any of the preceding embodiments, wherein the bottom surface comprises an upwardly curved portion extending from thesubstantially flat portion (wherein the substantially flat portion is arranged between the rear wall and the upwardly curved portion).

[0106] Embodiment 16. The apparatus of any of the preceding embodiments, wherein the upwardly curved portion of the bottom surface comprises the terminal edge of the bottom surface.

[0107] Embodiment 17. The apparatus of any of the preceding embodiments, wherein the bottom surface comprises a second substantially flat portion extending from the upwardly curved portion (wherein the upwardly curved portion is arranged between the first and second substantially flat portions).

[0108] Embodiment 18. The apparatus of any of the preceding embodiments, wherein the second substantially flat portion comprises the terminal edge of the bottom surface.

[0109] Embodiment 19. The apparatus of any of the preceding embodiments, wherein an angle between the second substantially flat portion and a surface on which the apparatus is disposed is about 15 ° to about 45 °, about 20 ° to about 40 °, about 25 ° to about 35 °, or about 30 °.

[0110] Embodiment 20. The apparatus of any of the preceding embodiments, wherein the bottom surface comprises a downwardly inclined portion that extends from the rear wall, and is arranged between the rear wall and first substantially flat portion or the upwardly curved portion.

[0111] Conveyors

[0112] Embodiment 21. The apparatus of any of the preceding embodiments, wherein the conveyor comprises, consists essentially of, or consists of a chain conveyor.

[0113] Embodiment 22. The apparatus of any of the preceding embodiments, wherein the conveyor comprises, consists essentially of, or consists of a sprocket, a chain, a paddle, or a combination thereof.

[0114] Embodiment 23. The apparatus of any of the preceding embodiments, wherein the conveyor comprises at least three, at least four, at least five, at least six, or at least seven sprockets, or at least three, at least four, at least five, at least six, or at least seven pairs of sprockets.

[0115] Embodiment 24. The apparatus of any of the preceding embodiments, wherein the conveyor comprises at least one paddle per X meters of the chain, wherein X is about 0.05 to about 2, about 0.05 to about 1.5. about 0.05 to about 1, about 0.1 to about 1, or about 0.1 to about 0.5.

[0116] Embodiment 25. The apparatus of any of the preceding embodiments, wherein the paddle contacts at least a portion of the bottom surface during one cycle of the chain.

[0117] Embodiment 26. The apparatus of any of the preceding embodiments, wherein the conveyor is configured to transport solids of the first product stream from the reservoir to the first outlet.

[0118] Embodiment 27. The apparatus of any of the preceding embodiments, wherein the conveyor is configured to transport solids of the first product stream from a position in the reservoir to a position beyond the terminal edge of the bottom surface.

[0119] Embodiment 28. The apparatus of any of the preceding embodiments, wherein the feed comprises, consists essentially of, or consists of a tailings stream (e.g., flotation tailings), an effluent stream (e.g., sieve effluent, screen effluent, screen bowl effluent, etc.), an overflow stream (e.g., classifying cyclone overflow, thickener overflow, clarifier overflow, etc.), etc.

[0120] Systems

[0121] Embodiment 29. A system comprising, consisting essentially of, or consisting of -

[0122] (A) (i) the apparatus of any of the preceding embodiments, and

[0123] (ii) at least one dewatering apparatus in fluid communication with the apparatus, wherein the at least one dewatering apparatus is arranged upstream of the apparatus or downstream of the apparatus;

[0124] wherein, optionally, a first dewatering apparatus is upstream of the apparatus, and a second dewatering apparatus is downstream of the apparatus;

[0125] wherein, optionally, the at least one dewatering apparatus is independently selected from a centrifuge (e.g., a solid bowl centrifuge or a screen bowl centrifuge), a belt filter press, a plate press, a horizontal belt vacuum filter, a rotary vacuum drum, a rotary vacuum disc filter, a thickener (e.g., a deep cone / paste thickener), a membrane pressure filter, or a combination thereof; or

[0126] (B) (i) the apparatus of any of the preceding embodiments, and a

[0127] (ii) screen bowl centrifuge (or other dewatering apparatus), wherein the apparatus and the screen bowl centrifuge (or other dewatering apparatus) are in fluid communication, and the screen bowl centrifuge (or other dewatering apparatus) is arranged upstream of the apparatus; or

[0128] (C) the system of FIG. 2.

[0129] Embodiment 30. The system of embodiment 29, further comprising a solid bowl centrifuge, wherein the solid bowl centrifuge is in fluid communication with the apparatus, and the apparatus is upstream of the solid bowl centrifuge.

[0130] Embodiment 31. The system of embodiment 29 or 30, wherein the other dewatering apparatus comprises, consists essentially of, or consists of a belt fdter press, a plate press, a horizontal belt vacuum fdter, a rotary vacuum drum, a rotary vacuum disc fdter, a thickener (e.g.. a deep cone / paste thickener), or a membrane pressure fdter.

[0131] Methods

[0132] Embodiment 32. A method of processing a material, the method comprising, consisting essentially of, or consisting of:

[0133] providing a first stream comprising, consisting essentially of. or consisting of a liquid and a plurality of solids dispersed in the liquid, wherein the plurality of solids is present at a first concentration;

[0134] contacting the first stream and a flocculant at an amount and for a time effective to form in the first stream a first area having an increased concentration of the plurality of solids relative to the first concentration, and a second area having a decreased concentration of the plurality of solids relative to the first concentration; and

[0135] optionally separating the first area and the second area to form a second stream comprising, consisting essentially of, or consisting of the first area, and, optionally, a third stream comprising, consisting essentially of. or consisting of the second area.

[0136] Embodiment 33. A method of processing a material, the method comprising, consisting essentially of, or consisting of:

[0137] providing the apparatus of any of the preceding embodiments;

[0138] providing a first stream comprising, consisting essentially of, or consisting of a liquid and a plurality of solids dispersed in the liquid, wherein the plurality of solids is present at a first concentration;

[0139] disposing the first stream in the reservoir of the apparatus via the inlet;

[0140] contacting the first stream and a flocculant at an amount and for a time effective to form in the first stream a first area having an increased concentration of the plurality of solids relative to the first concentration, and a second area having a decreased concentration of the plurality of solids relative to the first concentration, wherein the contacting of the first stream and the flocculant occurs before and / or after the disposing of the first stream in the apparatus; and

[0141] separating the first area and the second area with a skimming apparatus or the conveyor to form a second stream comprising, consisting essentially of, or consisting of the first area, and, optionally, a third stream comprising, consisting essentially of, or consisting of the second area.

[0142] Embodiment 34. The method of any of the preceding embodiments, wherein the method further comprises, consists essentially of, or consists of reducing particle and liquid interactions as the plurality of solids settles.

[0143] Embodiment 35. The method of any of the preceding embodiments, further comprising contacting the first stream and one or more lamella plates, subjecting the first stream to ultrasonic vibration, or a combination thereof.

[0144] Densities

[0145] Embodiment 36. The method of any of the preceding embodiments, wherein a density differential or an apparent density differential exists between the liquid and the plurality7of solids.

[0146] Embodiment 37. The method of any of the preceding embodiments, wherein a density of the plurality of solids is greater than a density of the liquid.

[0147] Embodiment 38. The method of any of the preceding embodiments, wherein the first area having the increased concentration of the plurality of solids is (or forms) below the second area having the decreased concentration of the plurality of solids; wherein, optionally, the second area is a froth; and wherein, optionally, if the froth is a relatively fine froth, then a pump, such as a specialty pump, may be used to transport the froth.

[0148] Embodiment 39. The method of any of the preceding embodiments, wherein an apparent density of the plurality of solids is less than a density of the liquid.

[0149] Embodiment 40. The method of any of the preceding embodiments, wherein the first area having the increased concentration of the plurality of solids is (or forms) above the second area having the decreased concentration of the plurality of solids; wherein, optionally, the first area is a froth; and wherein, optionally, if the froth is a relatively fine froth, then a pump, such as a specialty pump, may be used to transport the froth.

[0150] First Stream

[0151] Embodiment 41. The method of any of the preceding embodiments, wherein the liquid comprises, consists essentially of, or consists of water; for example, water may be present in the first stream (or feed) at a concentration of at least 50 %, at least 60 %, at least 70 %, at least 80 % at least 80 %, at least 90 %, at least 95 %. or at least 99 %, by weight, based on the weight of the first stream.

[0152] Embodiment 42. The method of any of the preceding embodiments, wherein the first stream is aerated.

[0153] Embodiment 43. The method of any of the preceding embodiments, wherein the providing of the first stream comprises aerating the first stream.

[0154] Embodiment 44. The method of any of the preceding embodiments, wherein when the first stream is aerated, the plurality of solids has an apparent density that is less than the density of the liquid.

[0155] Embodiment 45. The method of any of the preceding embodiments, wherein the first concentration of the plurality of solids (e.g., total suspended solids) is about 1 % to about 20 %, about 1 % to about 18 %, about 1 % to about 16 %, about 1 % to about 14 %, about 1 % to about 12 %, about 1 % to about 10 %, about 1 % to about 8 %, about 1 % to about 6 %, about 1 % to about 4 %, about 1 % to about 10 %, about 2 % to about 10 %, about 2 % to about 8 %, or about 2 % to about 6 %, by weight, based on the weight of the first stream.

[0156] Embodiment 46. The method of any of the preceding embodiments, wherein the first stream comprises, consists essentially of. or consists of a tailings stream, such as flotation tailings.

[0157] Embodiment 47. The method of any of the preceding embodiments, wherein the first stream comprises, consists essentially of, or consists of an effluent stream, such as a sieve effluent, screen effluent, an effluent from a centrifuge, such as a screen bowl centrifuge, etc.

[0158] Embodiment 48. The method of any of the preceding embodiments, wherein the first stream comprises, consists essentially of, or consists of an overflow stream, such as a classifying cyclone overflow, a thickener overflow, a clarifier overflow, etc.

[0159] Embodiment 49. The method of Embodiment 39, wherein the effluent is unmodified prior to being disposed in the apparatus or contacted with the flocculant.

[0160] First Area / Second Stream

[0161] Embodiment 50. The method of any of the preceding embodiments, wherein the first area having the increased concentration of the plurality of solids comprises, consists essentially of, or consists of a film that comprises, consists essentially of, or consists of solids.

[0162] Embodiment 51. The method of any of the preceding embodiments, further comprising disposing the second stream in a dewatering apparatus, such as a solid bowl centrifuge, a belt filter press, a plate press, a horizontal belt vacuum filter, a rotary vacuumdrum, a rotary vacuum disc filter, a thickener (e g., a deep cone / paste thickener), a membrane pressure filter, etc.

[0163] Embodiment 52. The method of any of the preceding embodiments, (i) wherein a concentration of the plurality of solids in the second stream is about 5 % to about 40 %, about 10 % to about 40 %, about 12 % to about 40 %, about 14 % to about 40 %, about 16 % to about 40 %, about 18 % to about 40 %, about 20 % to about 40 %, about 10 % to about 24 %, about 12 % to about 22 %, about 12 % to about 20 %, or about 14 % to about 20 %, by weight, based on the weight of the second stream; (ii) wherein a concentration of the plurality of solids in the second stream is about 2X to about 8X, about 2X to about 6X, about 2X to about 5X, or about 3X to about 5X, wherein X is the first concentration (for example, if the first concentration is 5 %, and the concentration of the plurality of solids in the second stream is 3X, then 15 % is the concentration of solids in the second stream); or wherein at least 80 %, at least 85 %, or at least 90 %, by weight, of the plurality of solids of the first stream are present in the second stream.

[0164] Embodiment 53. The method of any of the preceding embodiments, wherein the first area and / or the second stream comprises, consists essentially of, or consists of sludge concentrate.

[0165] Second Area / Third Stream

[0166] Embodiment 54. The method of any of the preceding embodiments, wherein the second area having the decreased concentration of the plurality of solids comprises, consists essentially of, or consists of clarified water.

[0167] Embodiment 55. The method of any of the preceding embodiments, wherein a concentration of the plurality of solids in the third stream is about 0. 1 % to about 5 %, about 0. 1 % to about 4 %, about 0. 1 % to about 3 %, about 0. 1 % to about 2 %, about 0.5 % to about 2 %, by weight, based on the weight of the third stream.

[0168] Embodiment 56. The method of any of the preceding embodiments, wherein the second area and / or the third stream comprises, consists essentially of, or consists of an effluent, froth concentrate, or a combination thereof.

[0169] Separating the First Area and the Second Area

[0170] Embodiment 57. The method of any of the preceding embodiments, wherein the separating of the first area and the second area comprises contacting the first area or the second area with a conveyor (such as the conveyor of any of the preceding embodiments) or a skimming apparatus.

[0171] Solids

[0172] Embodiment 58. The method of any of the preceding embodiments, wherein the plurality of solids comprises, consists essentially of. or consists of hydrophobic solids, such as hydrophobic minerals; for example, hydrophobic solids may be present at a concentration of at least 50 %, at least 60 %, at least 70 %, at least 80 %, at least 90 %, or at least 95 %, by weight, based on the weight of the plurality of solids.

[0173] Embodiment 59. The method of any of the preceding embodiments, wherein the plurality of solids comprises, consists essentially of. or consists of coal.

[0174] Embodiment 60. The method of any of the preceding embodiments, wherein the plurality of solids comprises, consists essentially of, or consists of (i) an ore, such as an industrial / metalliferous ore (e.g., iron ore) or phosphate ore, one or more platinum group metals (PGMs), or a combination thereof; (ii) a phosphorus-containing compound, such as a phosphate, a phosphorus oxide, or combination thereof; or (iii) one or more metals, one or more metal-containing compounds, or one or more minerals, wherein the metals may include one or more platinum group metals (PGM), such as “4e PGM” (platinum, palladium, rhodium, and gold), or 6e PGM (platinum, palladium, rhodium, ruthenium, osmium, and iridium), ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, iron, or a combination thereof, wherein the metal-containing compound may include a metal oxide, a metal carbonate, or a combination thereof, wherein the metal oxide may include iron oxide, and wherein the mineral may include gypsum.

[0175] Embodiment 61. The method of any of the preceding embodiments, wherein at least 80 %, at least 85 %, at least 90 %, at least 95 %, by weight, of the plurality of solids is not retainable by 325 mesh sieve (US standard sieve).

[0176] Flocculants

[0177] Embodiment 62. The method of any of the preceding embodiments, wherein the flocculant is present at any amount of about 0.01 % to about 5 %, about 0.01 % to about 4 %, about 0.01 % to about 3 %, about 0.1 % to about 2 %, or about 0.1 % to about 1 %, by w eight, based on the weight of the plurality' of solids.

[0178] Embodiment 63. The method of any of the preceding embodiments, wherein the flocculant is a non-ionic flocculant.

[0179] Embodiment 64. The method of any of the preceding embodiments, wherein the flocculant is an anionic flocculant.

[0180] Embodiment 65. The method of any of the preceding embodiments, wherein the flocculant is a cationic flocculant.

[0181] Embodiment 66. The method of any of the preceding embodiments, wherein the flocculant is a fatty acid / lipid flocculant.

[0182] Embodiment 67. The method of any of the preceding embodiments, wherein the flocculant is a polymeric flocculant, which includes a polymer, such as an acrylic polymer (e.g., a polyacry lamide), a polysaccharide (e.g., chitosan), poly (diallyl dimethyl-ammonium chloride), etc.

[0183] Embodiment 68. The method of any of the preceding embodiments, wherein when the flocculant is a polymeric flocculant, the polymer has a high molecular weight polymer (z.e., a polymer having an Mwof at least 100,000 g / mol), or a very' high molecular weight polymer (z.e., a polymer having an Mwof at least 10,000,000 g / mol).

[0184] Embodiment 69. The method of any of the preceding embodiments, wherein the flocculant is a non-ionic polymeric flocculant.

[0185] Embodiment 70. The method of any of the preceding embodiments, wherein the flocculant is a non-ionic high or very' high molecular weight polymeric flocculant.

[0186] Embodiment 71. The method of any of the preceding embodiments, wherein the flocculant is an anionic polymeric flocculant.

[0187] Embodiment 72. The method of any7of the preceding embodiments, wherein the flocculant is an anionic high or very' high molecular weight polymeric flocculant.

[0188] Embodiment 73. The method of any of the preceding embodiments, wherein the flocculant is a cationic polymeric flocculant.

[0189] Embodiment 74. The method of any of the preceding embodiments, wherein the flocculant is a cationic high or very7high molecular weight polymeric flocculant.

[0190] Embodiment 75. The method of any of the preceding embodiments, wherein the flocculant is a commercially-available flocculant, such as NALCO™ 749222 flocculant, YONGXING™ YX1224-6 flocculant, YONGXING™ PAM flocculant, YIXING™ APAM01 flocculant, ULTRACLEAR™ PROFLOCCULANT™ flocculant, GLORY™ flocculant, ZETAG™ 8127 flocculant (BASF, USA), ZETAG™ 4145 flocculant (BASF, USA), MAGNAFLOC® LT20 flocculant (BASF. USA), MAGNAFLOC® 338 flocculant (BASF, USA). MAGNAFLOC® 10 flocculant (BASF. USA), MAGNAFLOC® 155 flocculant (BASF, USA), MAGNAFLOC® 5250 flocculant (BASF, USA), RHEOMAX® 1050 flocculant (BASF, USA), RHEOMAX® ETD 9010 flocculant (BASF, USA), MAGNAFLOC® LT27AG polyacry lamide flocculant (BASF, USA), ZETAG™ 7109 acrylic homopolymer flocculant (BASF. USA), MAGNAFLOC® 333 flocculant (BASF, USA), FLOBEADS® KB206SH flocculant (SNF, UK), FLOBEADS® KB 156 flocculant(SNF, UK), FLOP AM® FO4190 flocculant (SNF, UK), FLOP AM® FO4140 flocculant (SNF, UK), FLOQUAT® TS 45 SH flocculant (SNF. UK), FLOP AM® FA920VHM flocculant (SNF, UK), FLOP AM® FA920VHR flocculant (SNF, UK), FLOP AM® FA920SD flocculant (SNF, UK), FLOPAM® FA920SHD flocculant (SNF, UK), FLOP AM® FA920 flocculant (SNF, UK), ALCLAR® 5000 flocculant (BASF, USA), ALCLAR® 600 flocculant (BASF, USA), ALCLAR® 661 flocculant (BASF, USA), ALCLAR® HP20 flocculant (BASF, USA), ALCLAR® HP21 flocculant (BASF. USA), ALCLAR® HP22 flocculant (BASF, USA), DRIMAX® 1235 flocculant (Allied Colloids Ltd., UK), DRIMAX® 1238 flocculant (Allied Colloids Ltd., UK), DRIMAX® 1240 flocculant (Allied Colloids Ltd., UK), LUPROMIN® F-20X flocculant (BASF, USA), LUPROMIN® FP 18 AS flocculant (BASF, USA), LUPROMIN® FP 199 (BASF, USA), HI-TEX® 82230 flocculant (Hi-Tex Corp, USA), or a combination thereof.

[0191] EXAMPLES

[0192] The present disclosure is further illustrated by the following examples, which are not to be construed in any way as imposing limitations upon the scope thereof. On the contrary, it is to be clearly understood that resort may be had to various other aspects, embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to one of ordinary skill in the art without departing from the spirit of the present invention or the scope of the appended claims. Thus, other aspects of this disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein.

[0193] Example 1 - Residual Flotation and Flocculant Flotation

[0194] Effluents, such as those from screen bowl centrifuges, produced a froth concentrate with no air added. The froth floated on the top of a container if allowed to stand for a period. Leftover air from flotation remained attached to the fine coal. This allowed the fine coal to float, but usually at a slow rate due to the size of the material. This was referred to as residual flotation, because it relied at least in part on residual chemicals and residual air from the prior processes. Typical results are shown in the following table.

[0195] Table 1. Residual Flotation

[0196] The foregoing tests were repeated with multiple feeds. The material floating was analyzed and found to be a good quality clean coal product that was at least 95 wt% minus 325 mesh sieve. The separation process was slow, but the clean coal was notably concentrated to about 9 wt% to about 16 wt% solids from a feed of about 2 wt% to about 6 wt% solids. Residual flotation yield was typically about 25 % to about 30 % (see, e.g., Sample 2 of Table 1), but the product was suitable for further processing, such as with a solid bowl centrifuge, including, but not limited to, processes described in International Patent Application No. PCT / IB2024 / 050856, International Patent Application No. PCT / IB2021 / 058136, and International Patent Application No. PCT / US2015 / 032878.

[0197] Additional analysis of the foregoing processes of this example were conducted. It was surprisingly discovered that flocculant addition to the feed stream greatly accelerated the concentration process. For example, the concentration process took several minutes (e.g., about 4 minutes) without the flocculant, but this time was reduced to less than a minute (e.g., about 20 seconds or less, and sometimes 15 seconds or less). As known in the art. however, the timing can vary in view of a number of factors, such as the type and / or character of solids. The float material in the flocculated samples separated to the froth phase much faster than the samples with no added flocculant. Flocculated samples separated in about 30 seconds instead of several minutes, as observed for the samples with no flocculant addition. Flocculant addition also greatly increased the yield from about 30% to about 90%. (see Table 2) It likewise increased the combustible recovery.

[0198] Table 2. Flocculant Flotation

[0199] The flocculant flotation of this example was a robust process. It consistently generated higher yields, and produced products having higher percentages of solids. This conclusion was visually evidenced by comparing photographs of products collected without flocculant (i.e., residual flotation), and with flocculant (i.e., flocculant flotation).

[0200] The feed of Sample 3 had the following size distribution, which was typical of the samples tested in this example.

[0201] Table 3. Size Distribution of Feed of Sample 3

[0202] The methods of this example allow for effective processing of a screen bowl effluent, but a number of adjustments are possible.

[0203] Several options exist with regard to feeds when a screen bowl centrifuge is employed in solids recovery, such as fine coal recovery7. A feed is prepared in several ways. For example, a flotation product can feed a first set of dedicated screen bowl centrifuges, and spiral concentrators can feed a second set of dedicated screen bowl centrifuges. This technique is referred to herein as a “Split Decision”. Typically, the screen bowl centrifuges that process the flotation product produce a product having a relative high moisture, and the screen bowl centrifuges that process the feed from a spiral concentrator produce a product having relatively low moisture. As a further example, the feeds from flotation and spiral concentrators can be combined prior to being processed by a single set of screen bowlcentrifuges, which can be acceptable because the products are ty pically combined after dewatering. This technique is referred to herein as a "Combined Decision”.

[0204] Combined Decision - The Combined Decision has been used, mainly due to its simplicity and results regarding moisture content. The weighted average moisture, in most processes, is substantially the same, with or without separate dedicated sets of screen bowl centrifuges (see Table 4), and the “Combined Decision” circuit is simpler because it includes only one set of screen bowl centrifuges.

[0205] Table 4. Screen Bowl Centrifuge Product Moisture

[0206] It should be noted, however, that ash quality of a screen bowl effluent material has not informed the foregoing decisions.

[0207] Split Decision - In view of the methods provided herein, including those of this example, and the ability to process the effluent accordingly, it is prudent to consider the effluent product produced from each feed stream.

[0208] It may be advantageous, in some instances, to split screen bowl duty. Separate screen bowl centrifuges, or sets thereof, are used, in some instances, for flotation product and non-flotation product to clean up the flotation effluent for recovery. The flotation coal is “cleaned” to a finer size than the product from a spiral circuit, as shown at Table 5.

[0209] Table 5. Screen Bowl Feeds. Combined Decision

[0210] Ultra-fines in a spiral screen bowl centrifuge effluent includes some high ash material, up to 70 wt% ash. The flotation effluent usually is low ash. typically under 20 wt% ash. The effluent from a spiral screen bowl centrifuge will be high ash, as shown in Table 6. Spiral screen bowl centrifuge effluent sometimes needs cleaning or disposal to reduce the ash of the flocculant flotation product and the total plant product. The hydrophilic high ash spiral fines also can cany’ excess moisture.

[0211] A Split Decision may be applied. For example, a spiral concentrator product may be processed by a separate screen bowl centrifuge, or set thereof, so that the effluent can be segregated. This improves effluent quality and product quality by selective rejection, since the flotation screen bowl effluent is fully recovered at better quality. Actions may be taken to reduce moisture, such as a moisture reduction action plan (MRAP)(see, e.g.. Toney. T. et al. “Manage Moisture to Increase Plant Yield,’’ CoalProTec 2022, Lexington, K.Y, USA), since product moisture can be an important element.

[0212] Table 6. Projected Screen Bowl Effluent, Split Decision (Projected with No Degradation)

[0213] Eliminating the screen bowl recirculation, in some instances, helps the fines circuit recover more fine coal. Additionally, the recovery of ultrafine material can improve the plant yield by recovering previously discarded material. Combined, these advances increase plant yield. However, the establishment of an MRAP (Moisture Reduction Action Plan) is recommended when product moisture is important. Additional cautions are listed below. As the ultrafine coal is recovered to the product, the flocculant utilized at the thickener is lowered in some instances; otherwise, the thickener may be over flocculated.

Claims

We claim -1. An apparatus comprising: a reservoir defined at least in part by a bottom surface, wherein a portion of the bottom surface is upwardly inclined, thereby imparting a depth gradient to the reservoir; an inlet configured to receive a feed, the feed comprising a liquid and a plurality of solids dispersed in the liquid, wherein the plurality of solids is present in the feed at an initial concentration; a first outlet configured to discharge a first product stream from the apparatus, wherein the first product stream comprises solids at a concentration greater than the initial concentration; a second outlet configured to discharge a second product stream from the apparatus, wherein the second product stream comprises an effluent; and a conveyor, wherein the conveyor is configured to transport the first product stream to the first outlet.

2. The apparatus of claim 1 , wherein the reservoir is defined at least in part by the bottom surface, a first side wall, a second side wall, and a rear wall, wherein the bottom surface extends from the rear wall and has a terminal edge opposite the rear wall, and wherein the conveyor is configured to transport the first product stream from a position in the reservoir to a position beyond the terminal edge of the bottom surface.

3. The apparatus of claim 1, the bottom surface comprises a first substantially flat portion extending from the rear wall.

4. The apparatus of claim 3, wherein the first substantially flat portion of the bottom surface is substantially parallel to a surface on which the apparatus is disposed.

5. The apparatus of claim 3, wherein the bottom surface comprises an upwardly curved portion extending from the first substantially flat portion.

6. The apparatus of claim 5, wherein the upwardly curved portion of the bottom surface comprises the terminal edge of the bottom surface.

7. The apparatus of claim 5, wherein the bottom surface comprises a second substantially flat portion extending from the upwardly curved portion.

8. The apparatus of claim 7, wherein the second substantially flat portion comprises the terminal edge of the bottom surface.

9. The apparatus of claim 8, wherein an angle between the second substantially flat portion and a surface on which the apparatus is disposed is about 15 ° to about 45 °.

10. The apparatus of claim 1, wherein the conveyor comprises a chain conveyor.

11. The apparatus of claim 10, wherein the chain conveyor comprises a sprocket, a chain, and a paddle affixed to the chain.

12. The apparatus of claim 11, wherein the at least one paddle is configured to contact at least a portion of the bottom surface during a portion of each cycle of the chain.

13. The apparatus of claim 1 , further comprising a plurality of lamella plates arranged in the reservoir.

14. A system comprising: the apparatus of any one of claims 1 to 13; and at least one dewatering apparatus, wherein the at least one dewatering apparatus is (i) in fluid communication with the apparatus, and (ii) arranged upstream or downstream of the apparatus.

15. A method of processing a material, the method comprising: providing the apparatus of any one of claims 1 to 13; providing a first stream comprising a liquid and a plurality of solids dispersed in the liquid, wherein the plurality of solids is present at a first concentration;disposing the first stream in the reservoir of the apparatus via the inlet; contacting the first stream and a flocculant at an amount and for a time effective to form in the first stream a first area having an increased concentration of the plurality of solids relative to the first concentration, and a second area having a decreased concentration of the plurality of solids relative to the first concentration, wherein the contacting of the first stream and the flocculant occurs before and / or after the disposing of the first stream in the apparatus; and separating the first area and the second area to form a second stream comprising the first area, wherein the separating of the first area and the second area comprises contacting (i) the first area and (ii) a skimming apparatus or the conveyor.

16. A method of processing a material, the method comprising: providing a first stream comprising a liquid and a plurality of solids dispersed in the liquid, wherein the plurality of solids is present at a first concentration; contacting the first stream and a flocculant at an amount and for a time effective to form in the first stream a first area having an increased concentration of the plurality of solids relative to the first concentration, and a second area having a decreased concentration of the plurality of solids relative to the first concentration; and separating the first area and the second area to form a second stream comprising the first area, and a third stream comprising the second area.

17. The method of claim 1 , wherein the flocculant is present at an amount of about 0. 1 % to about 2 %, by weight, based on the weight of the plurality of solids.

18. The method of claim 16, wherein a density differential or an apparent density' differential exists between the liquid and the plurality of solids.

19. The method of claim 18. wherein an apparent density of the plurality of solids is less than a density of the liquid.

20. The method of claim 16, wherein the providing of the first stream comprises aerating the first stream.

21. The method of claim 16, wherein the first concentration of the plurality of solids is about 2 % to about 8 %, by weight, based on the weight of the first stream.

22. The method of claim 1 , wherein the first stream comprises an effluent stream, a tailings stream, or an overflow stream.

23. The method of claim 22. wherein the effluent stream, the tailings stream, or the overflow stream is unmodified prior to being contacted with the flocculant.

24. The method of claim 16, wherein the first stream comprises an effluent of a screen bowl centrifuge.

25. The method of claim 16, wherein a concentration of the plurality of solids in the second stream is about 10 % to about 20 %, by weight, based on the weight of the second stream.

26. The method of claim 16, wherein the plurality of solids comprises hydrophobic solids.

27. The method of claim 26, wherein the hydrophobic solids are present in the plurality of solids at a concentration of at least 60 %, by weight, based on the weight of the plurality of solids.

28. The method of claim 16, wherein the plurality of solids comprises coal, an industrial ore. a metalliferous ore, a phosphate ore, one or more platinum group metals, or a combination thereof.

29. The method of claim 16, wherein at least 90 %, by weight, of the plurality of solids of the first stream is not retainable by a 325 mesh sieve.

30. The method of claim 16, wherein the flocculant is a polymeric flocculant.

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