SEPARATION OF MINERALS BY SPECIFIC GRAVITY

Abstract

A centrifuge for separating minerals by specific gravity is disclosed. The centrifuge rotates to circulate a slurry through a collection region and subject the slurry in the collection region to centripetal forces that facilitate stratification within the collection region by the specific gravity of the constituent minerals of the slurry. Energy, such as acoustic energy, is coupled with the collection region and enhances the specific gravity stratification within the collection region.

Description

SEPARATION OF MINERALS BY SPECIFIC GRAVITY CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application 62 / 652,494, entitled “SEPARATION OF MINERALS BY SPECIFIC GRAVITY”, filed on April 4, 2018. The above-mentioned application is incorporated herein by reference in its entirety. FIELD OF INVENTION

[0002] This disclosure relates to systems and methods for separating or concentrating higher specific gravity material from lower specific gravity material, such as heavy metals from a slurry fluid. BACKGROUND OF THE INVENTION

[0003] It is often desirable to extract particular minerals, such as heavy metals, from their surrounding materials, but the desired materials may be present in low concentrations relative to the surrounding materials and therefore be difficult to extract. For example, mining operations generate mixed material streams, from which desired materials are concentrated and extracted. Mining operations, however, generally fail to extract all the desired materials due to limitations in the technologies for concentrating and extracting specific materials from the mixed material streams produced by the mines. Many historical mines also used inferior extraction technologies, thus leaving tailings that contain significant quantities of valuable minerals.Additionally, historical mines produced tailings containing a large quantity of minerals, such as rare earth metals, that were not extracted during mine operation due to technological or economic factors (for example, the cost of extracting such materials may have exceeded the value of the recoverable materials given the technology available at the time). Modern mining operations are also constantly seeking cheaper and more efficient technologies to recover desired materials. Similarly, industrial processes can produce waste that includes harmful elements that must be removed for environmental, regulatory, or safety reasons.

[0004] This disclosure relates to systems and methods for recovering low concentration target materials, such as heavy metals, from surrounding materials. BRIEF DESCRIPTION OF THE INVENTION

[0005] Various examples of methods and apparatus for recovering target materials from mixed materials are disclosed. Without limiting the scope of the claims, some salient features of this disclosure will now be briefly described. ferocious in / nznz / □ / yl

[0006] One aspect of the disclosed technology is a device for separating a first mineral of a first specific gravity from at least a second mineral of a second specific gravity that is lower than the first specific gravity. The device includes a centrifuge configured to rotate about an axis. At least one collection region is configured to undergo centripetal acceleration when the centrifuge rotates about the axis. At least one energy injection module is coupled to the collection region and configured to provide oscillating energy to the collection region. The collection region and the energy injection module are configured to stratify the first and second minerals.

[0007] In some embodiments, the energy injection module is configured to provide acoustic energy to the collection region. The energy injection module may be configured to provide acoustic energy at a subsonic frequency. The energy injection module may be configured to provide acoustic energy at a plurality of frequencies simultaneously.

[0008] In some embodiments, the energy injection module is configured to provide oscillating pressure waves to the collection region. The energy injection module may be configured to provide oscillating energy to the collection region in such a way that the oscillating energy propagates to the collection region along a direction substantially parallel to the centripetal acceleration in the collection region.

[0009] In some embodiments, the device additionally includes a membrane between the collection region and the energy injection module.

[0010] In some embodiments, the centrifuge is configured to receive the first and second minerals in slurry. The centrifuge may also be configured to circulate the slurry through the collection region as the centrifuge rotates around its axis.

[0011] In some embodiments, the device additionally includes at least one spring acting on the energy injection module and counteracting at least part of the centripetal acceleration in the energy injection module.

[0012] In some embodiments, the device additionally includes at least one sensor that measures a quantity of material present in the collection region. For example, the device may include at least one sensor that measures the mass of material collected in the collection region.

[0013] Another aspect of the disclosed technology is a method for separating a first mineral of a first specific gravity from at least a second mineral of a second specific gravity that is lower than the first specific gravity. The method includes obtaining a fluidized slurry containing the first and second minerals. The slurry is spun in a centrifuge such that the slurry circulates within the centrifuge and through at least one collection region. At least a portion of the slurry is received in the collection region, which is subjected to centripetal forces due to the rotation of the centrifuge about its axis. Energy waves are generated and injected into the collection region. The first and second minerals stratify in the collection region.

[0014] In some modalities, generating energy waves comprises generating acoustic waves. For example, generating acoustic waves may comprise generating subsonic waves. Generating acoustic waves may also comprise generating acoustic waves at a plurality of simultaneous frequencies.

[0015] In some modalities, generating energy waves involves generating pressure waves.

[0016] In some modalities, generating the energy waves involves generating at least one standing wave in the collection region.

[0017] In some embodiments, obtaining the fluidized slurry comprises grinding the first and second minerals in such a way that the first and second minerals have a maximum particle size of 100 microns and adding a fluid to the first and second minerals.

[0018] In some modalities, the method additionally includes, while the centrifuge is rotating, weighing the material collected within the collection region.

[0019] In some embodiments, generating the energy waves comprises generating the energy waves with an energy injection module separated from the collection regions by a movable membrane, and the method also includes, while the centrifuge is rotating, determining a weight of the material collected within the collection region based on a measured deflection of the movable membrane and based on a rotation speed of the centrifuge. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1A schematically illustrates an example of a material separation system.

[0021] Figure 1B schematically illustrates an exemplary energy injection module and collection region for stratifying materials by specific weight.

[0022] Figure 2 shows a schematic cross-sectional side view of a centrifuge for separating materials by specific weight.

[0023] Figure 3 is a close-up schematic diagram of radially mounted power injection modules and collection regions in the centrifuge of Figure 2.

[0024] Figure 4 is a process flow diagram of an example of a method for using a material separation system.

[0025] Throughout the drawings, reference numbers may be reused to indicate correspondence between referenced items. The drawings are provided to illustrate exemplary modalities described herein and are not intended to limit the scope of disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0026] Reference will now be made to the drawings, in which the reference numbers refer to similar parts throughout the text. Unless otherwise indicated, the drawings are schematic and not necessarily drawn to scale.

[0027] Figure 1A shows a system 100 for separating minerals by specific gravity with a fierce centrifuge 108.

[0028] In Figure 1A, a suitable feed 102 is combined with a fluid 104 to form a slurry 106. In some embodiments, the slurry can be fed to a centrifuge 108. In some embodiments, the slurry can be formed within the centrifuge from separate feeds of dry material (e.g., powder) and fluid (e.g., liquid). In some embodiments, the feed 102 can be mine tailings, industrial waste, or other materials containing minerals of different specific gravity. In some embodiments, the feed 102 can include materials from volcanic fumaroles on the seafloor, alluvial fans of rivers, materials from asteroids and other celestial bodies, or any other source of materials containing minerals of different specific gravity.

[0029] In at least some embodiments, the Centrifuge 108 can be operated in a reduced-gravity or zero-gravity environment, such as in orbit around a celestial body or on the surface of a natural or artificial object other than Earth. If desired, the Centrifuge 108 can be modified for low-gravity operation, such as by sealing an otherwise open section (such as a top) of the Centrifuge 108. As another example, the Centrifuge 108 can be integrated into a Mobile Processing Unit (MPU) capable of transporting the Centrifuge 108 to a desired location on a natural or artificial object other than Earth. The MPU can be capable of collecting and pre-processing material (for example, the MPU can include crushers and / or rotary screening devices to pre-process regolith or other material sources to a desired grain size).Additionally, the MPU and / or centrifuge 108 may include screw conveyors or paddles to assist in the movement of materials through the centrifuge 108 and related components (e.g., inlet hoppers, outlet hoppers, etc.), which can be particularly beneficial in low-gravity environments where gravity cannot be relied upon to move materials. In some embodiments, the MPU may include internal and / or external storage for storing valuable materials such as concentrate 116. As a particular example, the MPU may include mechanisms for robotically removing saturated collection cells (such as collection region 144 and collection regions 210a, 210b) from the centrifuge and storing the saturated collection cells for later collection.

[0030] In various configurations, the centrifuge 108 can be operated in environments with varying temperatures (e.g., environments on Earth, in space, or on the surface of non-Earth objects subject to extreme cold, extreme heat, or both). If desired, the centrifuge 108 can be modified for operation in environments with varying temperatures, such as extreme cold or extreme heat. For example, a cold-tolerant fluid such as ammonia can be used as fluid 104 when the centrifuge 108 is operated in cold environments on Earth or in space. As another example, cold-tolerant materials (e.g., materials that are not excessively brittle and maintain sufficient structural strength at low temperatures) can be used to form the structure of the centrifuge 108.As yet another example, centrifuge 108 may include heating elements that heat centrifuge 108, fluid 104, slurry 106, and / or other components of centrifuge 108. In environments such as the Moon, extracted materials such as regolith may be excessively hot at the surface and excessively cold below the surface. In such environments, centrifuge 108 may be fed with a selective mixture of surface regolith and subsurface regolith to achieve a desired temperature of the working materials (e.g., so that the feed source 102 is within a suitable temperature range).

[0031] If desired, alternatives to fluid 104 may be used as a means of separating the material. In particular, fluid 104 may be replaced with a solid medium formed from balls or grains, which may be larger in size than the feed 102 separated by centrifuge 108. Such a solid carrier medium could be recovered using a rotary screen or other recovery mechanism. Solid medium alternatives to fluid 104 may be beneficial in overcoming fluid problems under severe temperature and / or low pressure or vacuum conditions. The modalities described herein are particularly suitable for low or zero gravity and cold environments typical of extraterrestrial applications and may operate without human intervention.

[0032] In some embodiments, the feedstock 102 may include tailings or other similar materials that have been ground to a suitable particle size or a suitable range of particle sizes. As an example, the feedstock 102 may include materials that have been ground, or otherwise processed, such that the nominal maximum particle size in the feedstock 102 is in the range of approximately 50 microns to 200 microns, for example, approximately 100 ± 15 microns. In some embodiments, the feedstock 102 may be combined with a fluid 104 such as water or ammonia to form slurry 106 (for example, fluidized slurry 106). The fluid 104 may include any suitable fluid and, if desired, may include chemicals that aid in specific gravity stratification within the centrifuge 108.As an example, fluid 104 may include lubricants, surfactants, and other chemicals that facilitate or accelerate specific gravity stratification within centrifuge 108. As another example, fluid 104 may include antifreeze additives that lower the fluid's freezing point, helping to prevent freezing of fluid 104 when centrifuge 108 is operating in cold environments, such as extraterrestrial environments. As mentioned previously, in various configurations, slurry 106 can be created within centrifuge 108 by separately adding fluid 104 and feedstock 102 to centrifuge 108.

[0033] Slurry 106 can be processed by centrifuge 108 to produce concentrate 116 and tailings 114. As depicted in Figure 1A, centrifuge 108 can rotate (as indicated by arrow 112) to produce centripetal forces (e.g., centripetal acceleration) that are significantly greater than the acceleration due to gravity. These centripetal forces can facilitate the separation of components from slurry 106 based on the different specific gravities of those components. In other words, minerals in slurry 106 with a higher specific gravity may tend to sink, while minerals in slurry 106 with a lower specific gravity may tend to rise in an acceleration field (such as gravity or the radially directed field found in a centrifuge).By using a centrifuge that provides substantial centripetal forces, the separation of materials by specific weight can be accelerated.

[0034] In some embodiments, the slurry 106 can be processed by means of multiple centrifuges 108 coupled together in series, where each centrifuge processes the rejected material, or tailings 114, from a previous centrifuge. In such embodiments, multiple stages of centrifuges coupled together in series can be configured to separate a variety of materials from the slurry 106.As an example, an initial stage consisting of one or more centrifuges can separate a first material of a specific gravity; a second stage consisting of one or more additional centrifuges can receive the tailings from the initial stage and separate a second material of a lower specific gravity; a third stage consisting of one or more additional centrifuges can receive the tailings from the second stage and separate a third material of a lower specific gravity; and so on for as many stages as desired. Such arrangements can enable the processing of a wide range of materials, from high to low specific gravity, from a single feed source.

[0035] In some embodiments, multiple 108 centrifuges can be coupled together in parallel to increase processing speed and / or volume. In other embodiments, both series and parallel coupling configurations are provided. As an example, the 100 system may include a first stage formed from one or more 108 centrifuges coupled together in parallel, and the first stage may be coupled in series with at least one second stage formed from one or more centrifuges coupled together in parallel. In such an example, the first stage can separate a first mineral of a relatively heavy specific gravity, while the second stage can separate a second mineral of a lower specific gravity than the first mineral. In general, the stages need not be formed from identical numbers of centrifuges coupled together in series.As an example, a first stage may consist of a single centrifuge, while a second stage may consist of two or more centrifuges connected in parallel. In general, references to a centrifuge in this disclosure are not limited to a single centrifuge and rather encompass a single centrifuge and combinations of multiple centrifuges connected in series, in parallel, or a combination of series and parallel connections.

[0036] As represented by sound waves, also known as acoustic energy 110, the centrifuge 108 can be assisted by coupling vibrations or oscillating energy to the fluid in the centrifuge 108. In some embodiments, the energy can be in the acoustic range, and the centrifuge can be referred to as an acoustically assisted centrifuge 108, although it will be understood that in some embodiments the desired energy can oscillate outside the acoustic range. As an example, the centrifuge 108 can include one or more acoustic modules that provide acoustic energy 110 to the slurry 106 within the centrifuge 108. The energy 110 can represent, for example, subsonic sound waves. As examples, the energy 110 can oscillate from 0.5 Hz to 9 Hz and can vary between 0.5 Hz and 9 Hz over time. As another example, energy 110 can vary between 0.5 Hz and 40 Hz over time.

[0037] Acoustic energy 110 can include, in different modalities, oscillations at multiple frequencies provided simultaneously, sometimes referred to as polyphonic energy. For example, energy 110 can include energy of multiple acoustic frequencies. In some modalities, different frequencies of energy 110 can create different desired effects. As an example, a first frequency (or set of frequencies) can be adjusted to increase the mobility of a first mineral, while a second frequency (or set of frequencies) can be adjusted to increase the mobility of a second mineral or a fluid component of the slurry in centrifuge 108.As another example, a first frequency (or set of frequencies) can be provided to reduce friction or adhesion between particles, while a second frequency (or set of frequencies) can be provided to push minerals of a lower specific weight than desired out of the collection regions.

[0038] If desired, acoustic energy 110 may include energy that cancels, minimizes, or reduces unwanted ambient energy or energy created by a system component. As an example, there may be ambient acoustic energy or acoustic energy created by the operation of centrifuge 108 that decreases the stratification rate in the centrifuge, depending on the materials of interest and the dimensions of the centrifuge. In such examples, acoustic energy 110 may include energy that cancels such unwanted acoustic energy.

[0039] In some embodiments, the frequency or frequencies of energy 110 can be configured to increase the fluidization of the slurry components 106. In particular, acoustic energy 110 can help reduce friction between slurry components 106, thereby accelerating the separation of materials by specific weight under an accelerating force (such as the centripetal forces generated by the centrifuge 108). In different embodiments, energy 110 can increase lubrication in the slurry 106 within the collection rows, induce supercavitation within the collection rows, or create one or more stationary waves within the collection regions.

[0040] If desired, the centrifuge 108 may be assisted by something other than oscillating energy of the type represented by sound waves 110. As an example, in some embodiments, the system 100 may include an energy injection module that injects air or fluid into the centrifuge 108 and, in particular, injects air or fluid into the collection rows (such as rows 144 in Figure 1B). Injecting air or fluid into the collection rows may help disturb the sediment, reduce friction between slurry components 106, and / or otherwise aid in the stratification of materials by specific gravity within the collection regions. In some embodiments, the injected air or fluid has a lower specific gravity than the ore being concentrated and may have the effect of washing lower-gravity minerals out of the collection regions.

[0041] Figure 1B illustrates an example of an energy injection module 140 of the type capable of generating the energy 110 of Figure 1A. The energy injection module 140 can be separated from a collection region 144 by a membrane 142. As shown in Figure 1B, the slurry within the collection region 144 can stratify by specific gravity due to the centripetal forces 150 of the rotating centrifuge 108 and with the assistance of the energy 110 from the energy injection module 140. In particular, the slurry components 106 that have the highest specific gravity tend to migrate outward from the centrifuge 108 (e.g., the direction of the centripetal force 150 illustrated in Figure 1B), while the components that have lower specific gravity can migrate inward.The energy injection module 140 can vibrate (e.g., in directions parallel to the centripetal forces 150 and at suitable frequencies, which can be in the subsonic range) and the vibrations of the energy injection module 140 can be transmitted as energy 110 through the membrane 142 to the collection region 144. As an example, the energy injection module 140 can produce energy that propagates parallel to the direction of the centripetal force 150, as illustrated in Figure 1B. The energy 110 can reduce the friction between the slurry particles 106, thereby increasing the stratification rate according to specific weight within the collection region 144.

[0042] The membrane 142 can be formed from materials that facilitate the coupling of energy from module 140 to the collection region 144. As examples, the membrane 142 can be formed from Kevlar, graphene, steel, titanium, titanium nitride, rubber, synthetic rubber, metal, plastic, other suitable materials, or combinations of these and other suitable materials. In some embodiments, the membrane 142 can be a flexible membrane.

[0043] Referring again to Figure 1A, concentrate 116 can be produced by one or more centrifuges 108, which can be coupled together in series, in parallel, or in configurations that include combinations of parallel and series. In different embodiments, concentrate 116 can represent slurry components 106 that have the highest specific gravity. Similarly, tailings 114 can be produced by centrifuge 108 and can represent slurry components 106 that have the lowest specific gravity. While tailings are sometimes referred to as a waste product, in some embodiments, tailings 114 can be a desired product (e.g., such as in examples where concentrate 116 represents an undesirable contaminant).

[0044] As shown by path 118, the excess fluid can be extracted from tailings 114 and reused as feed fluid, thereby cyclically treating the material to progressively extract more minerals.

[0045] A cross-sectional side view of a centrifuge 200 is shown in Figure 2. The centrifuge 200 in Figure 2 may be an example of the centrifuge 108 discussed in relation to Figures 1A and 1B. As shown in Figure 2, the centrifuge 200 may have sidewalls 202 that rotate in direction 204 about axis 206, producing centripetal forces 207. These centripetal forces 207, which can be significantly greater than gravitational acceleration, can increase the specific gravity stratification rate of the constituents of the slurry processed by the centrifuge 200. The centrifuge 200 can rotate about axis 206 at a speed (e.g., revolutions per minute or RPM) sufficient to produce, in combination with the radius of the centrifuge 200, the desired magnitude of the centripetal forces 207. As an example, the centrifuge 200 can rotate at approximately 500 RPM.Centrifuge 200 can be made of suitable materials. If desired, the walls and internal components of centrifuge 200 can be coated with high-wear coatings such as titanium nitride, ceramics, metals, etc., which can help prevent rapid abrasion of the slurry 208. If desired, centrifuge 200 can include control circuitry that prevents operation of the centrifuge 200 unless one or more wear items are replaced, repaired, or otherwise reconditioned after a certain number of operating hours, which can be predetermined or determined based on the observed operating conditions.

[0046] As shown in Figure 2, the slurry 208 can circulate within the centrifuge 200. In particular, the slurry 208 can be pressed against the side walls 202 by means of centripetal forces 207. The upper portion of the side walls 202 can be curved inward, such that the slurry 208 migrating upward from the side walls is thrown toward the bottom of the centrifuge. As a result, the slurry can circulate in the manner illustrated in Figure 2. If desired, the centrifuge 200 can include a stator (e.g., a stationary element that does not rotate with the centrifuge or rotates at a lower speed) on top of the side walls 202.Such a stator can direct the amount of slurry movement reaching the top of the side walls 202 so that the slurry is directed back to the bottom of the centrifuge, thereby improving the circulation of the slurry 208 within the centrifuge. In some embodiments, such a stator may be curved to help direct the slurry 208 downward and inward from the top of the centrifuge at the side walls 202 to the central bottom of the centrifuge 200. The downward direction of the slurry by the stator may be useful in terrestrial and extraterrestrial environments (low or zero gravity). In some embodiments, the centrifuge 200 may be sealed. Additionally, the centrifuge 200 may include mechanisms, such as movable valves and gates, that facilitate the addition of slurry 208 and the removal of slurry and / or concentrate.A 200 centrifuge operated in a sealed configuration can be beneficial for operations in a reduced gravity environment.

[0047] The circulating slurry 208 can pass through the collection regions, including collection region 210a. As the slurry 208 passes through the collection regions, such as region 210a, particles with higher specific gravities can become trapped within the collection regions. In at least some embodiments, the collection regions 210a can be removably attached to the side walls 202 of the centrifuge 200.

[0048] Figure 2 also illustrates a housing 214, which may include energy injection generators such as the illustrated generator 218a that inject energy 212, which may be pressure waves, acoustic energy, or other forms of energy, into the collection regions such as region 210a. The housing 214 may, in at least some embodiments, be removably coupled to the centrifuge. As discussed with reference to Figures 1A and 1B, energy injection generators such as generator 218a can enhance and accelerate the specific gravity stratification of minerals in the slurry 208 within the collection regions. Additionally, the energy injection generators can help prevent clogging of the collection regions by stimulating mixing of the slurry within the collection regions with the slurry passing through them.In particular, energy injection generators can drive the exchange of stratified minerals with lower specific gravities located at the top (e.g., radially inward in the orientation of centripetal forces 207) of the collection regions with mixed slurry flowing through the collection regions. In this way, the minerals in the slurry 208 that have the larger specific gravities may tend to collect or concentrate at the bottom of the collection regions (e.g., radially outward in the orientation of centripetal forces 207).

[0049] In some embodiments, the centrifuge 200 may include a waste drain 216. In such embodiments, the waste drain 216 can be opened as the slurry 208 is discharged from the centrifuge 200 when desired. For example, after the minerals with the highest specific gravities concentrate in the collection regions, the remaining slurry 208 may be free of such minerals, and the waste drain 216 can be opened. If desired, the waste drain 216 can be opened while the centrifuge 200 is still rotating (for example, with or without slowing the centrifuge 208 from its typical operating speed). After draining the waste slurry through the waste drain 216, fresh slurry 208 can be added to the centrifuge 200 for further processing.

[0050] A close-up diagram of the injection modules 218 and the collection rows 210 of Figure 2 is shown in Figure 3. As shown in Figure 3, the slurry 208 can pass over the collection rows 210a, 210b, etc. and the centripetal forces 207 (from the rotation of the centrifuge 200) can press the slurry 208 into the collection regions.

[0051] As shown in Figure 3, the housing 214 can contain one or more collection regions 210a, 210b, etc., each of which can be associated with an energy injection module 218a, 218b, etc. Furthermore, the housing 214 can be removably coupled to the centrifuge side walls 202. As discussed in connection with Figures 1A, 1B, and 2, the energy injection modules, such as modules 218a and 218b, can be separated from the collection regions by membranes, such as membranes 222a and 222b. The membranes separating the energy injection modules from the collection regions, such as membranes 222a and 222b, can be formed from materials that facilitate the coupling of energy from module 140 to the collection region 144.For example, membranes can be made of Kevlar, graphene, steel, titanium, titanium nitride, rubber, synthetic rubber, metal, plastic, other suitable materials, or combinations of these and other suitable materials. In some versions, the membranes can be flexible.

[0052] In at least some embodiments, the energy injection modules 218a, 218b, etc. can be held against the collection regions 210a, 210b, etc. by means of springs 220a, 220b, etc. The springs 220a, 220b can provide a force opposing the centripetal forces 207, such that the energy injection modules 218a, 218b remain in communication with the collection regions 210a, 210b so that they can couple the energy into the collection regions without having to overcome the centripetal forces 207. In at least some embodiments, the springs 220a, 220b can provide a variable spring force that can be varied with respect to the rotational speed of the centrifuge 200 and with respect to the mass of minerals in the collection lines 210a, 210b.As an example, the spring force provided by springs 220a and 220b can be increased by increasing the rotational speed of centrifuge 200 and can be further increased as minerals with higher specific gravities are collected in the collection regions. In some embodiments, springs 220a and 220b can be formed from air chambers, and the spring force can be increased or decreased by pumping air into or out of the air chambers.

[0053] If desired, the centrifuge 200 may include sensors that measure the mass of material within the collection regions 210a, 210b. As an example, the springs 220a, 220b may include sensors that detect how much force is imparted to the springs by the mass within the collection regions (which is subject to the centripetal forces 207). The mass of material within the collection regions 210a, 210b can be used to determine whether the centrifuge is properly balanced, whether the stiffness of a spring needs to be increased (for example, by pumping more air into a suitable air chamber), or whether a particular collection region is full or obstructed.In at least some embodiments, the 200 centrifuge may include control circuitry configured to use information from such sensors to balance the centrifuge (e.g., by selectively disabling one or more power injection modules to reduce the rate of mass accumulation in those modules), to determine when slurry processing is complete (e.g., when the desired materials having the largest specific weights have been adequately concentrated in the collection regions), or for other purposes.

[0054] As shown in Figure 3, the slurry 208 can stratify within the collection regions 210a, 210b according to specific gravity, with the heavier minerals accumulating at the “bottom” (e.g., the outside of the centrifuge 200) of the collection regions. Additionally, lighter minerals can escape from the collection regions, allowing fresh slurry to enter them. As a result, the heavier minerals can accumulate in the portions of the collection regions furthest from the centrifuge shaft over time.

[0055] Figure 4 is a process flow diagram of an exemplary Method 400 for separating minerals by specific gravity using a centrifuge with power coupled to it to enhance stratification. Method 400 can be carried out, for example, by means of the centrifuge described in this document.

[0056] In block 402, materials for centrifuge processing can be obtained. As discussed in this document, the materials can be mine tailings or other material streams that include a mixture of minerals with different specific gravities. Additionally, the materials can be ground, screened, or otherwise processed in preparation for centrifuge separation. For example, the materials can be processed to achieve a suitable particle size.

[0057] In block 404, the materials can be mixed with a suitable fluid into a slurry. In some embodiments, the slurry can be added to the centrifuge. In at least some embodiments, the centrifuge can be rotating during the addition of the slurry. In other embodiments, the centrifuge can be rotated after the introduction of the slurry. In other embodiments, the slurry can be formed within the centrifuge by the separate addition of dry material, such as powder, and fluid.

[0058] In block 406, the centrifuge can be rotated, and modules can be activated to introduce energy into the centrifuge's collection regions. As discussed with respect to Figures 1A to 3, both the centripetal forces generated by the centrifuge's rotation and the lubricating energy coupled to the collection regions (e.g., acoustic energy produced by the energy injection modules, which can be acoustic modules) can enhance and accelerate the concentration and stratification of minerals with high specific densities in the centrifuge's collection regions.As examples, the energy injected by the energy injection module can increase lubrication between particles in the grout, can reduce friction within the grout, can create standing waves within the collection regions that reduce friction between particles in the grout, and / or can induce supercavitation that reduces friction between particles in the grout.

[0059] In block 408, residual slurry can be removed or expelled from the centrifuge. In some embodiments, block 408 can be performed after sensors in the centrifuge determine that the collection regions are full, nearly full, filled to a desired capacity, or that the mass of the collection regions has stabilized (e.g., indicating that any higher specific gravity mineral in the slurry is already contained within the collection rows and that the circulating slurry should be discarded). As noted by arrow 410, additional slurry can be added to the centrifuge after the residual slurry is expelled in block 408. In other words, blocks 404, 406, and 408 can be repeated as required.In some modes, blocks 404, 406, and 408 can be repeated until the sensors in the centrifuge indicate that the collection regions are full or nearly full of material that has a high specific gravity.

[0060] In block 412, heavy materials, or materials with a high specific gravity, can be extracted from the centrifuge. In some configurations, block 412 may involve stopping the centrifuge and physically removing and emptying the collection regions, which now contain concentrated high-specific-gravity minerals.

[0061] Unless the context clearly indicates otherwise, throughout the description and claims, the words “comprises,” “comprising,” “includes,” “including,” and the like should be interpreted in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is, in the sense of “including, but not limited to.” The word “coupled,” as generally used herein, refers to two or more elements that may be coupled directly to each other or coupled by means of one or more intermediate elements. Likewise, the word “connected,” as generally used herein, refers to two or more elements that may be connected directly or connected by means of one or more intermediate elements.Additionally, the words “in this document,” “previously,” and any words of similar implied meaning, when used in this application, shall refer to this application as a whole and not to any particular portion of it. Where context permits, words in the Detailed Description above that use the singular or plural number may also include the plural or singular number, respectively. Where context permits, the word “or” in reference to a list of two or more items is intended to cover all of the following interpretations of the word: any one of the items in the list, all of the items in the list, and any combination of the items in the list.

[0062] Furthermore, the conditional language used in this document, such as, among others, “may,” “could,” “for example,” “such as,” and the like, unless specifically stated otherwise or otherwise understood within the context in which it is used, is generally intended to convey that certain modalities include, while other modalities do not include, certain features, instances, and / or states. Therefore, such conditional language is not generally intended to imply that the features, elements, and / or states are in any way required for one or more modalities.

[0063] While certain embodiments have been described, these embodiments are presented by way of example and are not intended to limit the scope of the disclosure. In fact, the novel methods, apparatus, and systems described herein may be incorporated in a variety of other ways. Furthermore, various omissions, substitutions, and changes may be made to the form of the methods, apparatus, and systems described herein without departing from the spirit of the disclosure. For example, device components described herein may be removed, moved, added, subdivided, combined, and / or modified. Each of these device components may be implemented in a variety of different ways. The appended claims and their equivalents are intended to cover any such forms or modifications as would fall within the scope and spirit of the disclosure.

[0064] The foregoing description is intended to be illustrative and not restrictive. For example, the examples described above (or one or more aspects thereof) may be used in combination with one another. Other embodiments may be used, such as by someone skilled in the art, upon reviewing the foregoing description. The Summary is provided to enable the reader to quickly ascertain the nature of the technical disclosure. It is presented with the understanding that it shall not be used to interpret or limit the scope or significance of the claims. Also, in the Detailed Description above, different features may be grouped together for the sake of coordination of disclosure. This should not be construed as implying that a disclosed non-claimed feature is essential to any claim. Rather, the inventive matter may reside in fewer than all the features of a particular disclosed embodiment.Therefore, the following claims are incorporated herein in the Detailed Description, with each claim standing alone as a separate embodiment. The scope of the invention shall be determined with reference to the appended claims, together with the full scope of equivalents to which such claims are entitled. ferocious in / nznz / □ / yl

Claims

1. A device for separating a first mineral of a first specific gravity from at least a second mineral of a second specific gravity that is less than the first specific gravity, the device comprising: a centrifuge configured to rotate about an axis; at least one collection region subjected to centripetal acceleration when the centrifuge rotates about the axis; and at least one energy injection module coupled to the collection region and configured to provide oscillating energy to the collection region, wherein the collection region and the energy injection module are configured to stratify the first and second minerals.

2. The device according to claim 1, wherein the energy injection module is configured to provide acoustic energy to the collection region.

3. The device according to claim 2, wherein the energy injection module is configured to provide acoustic energy at a subsonic frequency.

4. The device according to claim 2, wherein the energy injection module is configured to provide acoustic energy at a plurality of frequencies simultaneously.

5. The device according to claim 1, wherein the energy injection module is configured to provide oscillating pressure waves to the collection region.

6. The device according to claim 1, wherein the energy injection module is configured to provide oscillating energy to the collection region in such a way that the oscillating energy propagates to the collection region along a direction substantially parallel to the centripetal acceleration in the collection region.

7. The device according to claim 1, further comprising a membrane between the collection region and the energy injection module.

8. The device according to claim 1, wherein the centrifuge is configured to receive the first and second minerals in slurry.

9. The device according to claim 1, wherein the centrifuge is configured to receive the first and second minerals in slurry and is configured to circulate the slurry through the collection region as the centrifuge rotates about the axis.

10. The device according to claim 1, further comprising at least one spring acting on the energy injection module and counteracting at least part of the centripetal acceleration in the energy injection module.

11. The device according to claim 1, further comprising at least one sensor that measures a quantity of material present in the collection region.

12. The device according to claim 1, wherein the material is collected in the collection region, wherein the material has a mass, and wherein the device further comprises at least one sensor that measures the mass of material collected in the collection region.

13. A method for separating a first mineral of a first specific gravity from at least a second mineral of a second specific gravity that is less than the first specific gravity, the method comprising: obtaining a fluidized slurry containing the first and second minerals; rotating a centrifuge containing the slurry about an axis such that the slurry circulates within the centrifuge and through at least one collection region; receiving at least a portion of the slurry in the collection region; subjecting the collection region to centripetal forces due to the rotation of the centrifuge about the axis; generating energy waves and injecting the energy waves into the collection region and stratifying the first and second minerals in the collection region.

14. The method according to claim 13, wherein generating the energy waves comprises generating acoustic waves.

15. The method according to claim 14, wherein generating the acoustic waves comprises generating subsonic waves.

16. The method according to claim 14, wherein generating the acoustic waves comprises generating acoustic waves at a plurality of simultaneous frequencies.

17. The method according to claim 13, wherein generating the energy waves comprises generating pressure waves.

18. The method according to claim 13, wherein generating the energy waves comprises generating at least one standing wave in the collection region.

19. The method according to claim 13, wherein obtaining the fluidized slurry comprises grinding the first and second minerals such that the first and second minerals have a maximum particle size of 100 microns and adding a fluid to the first and second minerals.

20. The method according to claim 13, further comprising: while the centrifuge is rotating, weighing the material collected within the collection region.

21. The method according to claim 13, wherein generating the energy waves comprises generating the energy waves with an energy injection module separated from the collection regions by a movable membrane, the method further comprises: while the centrifuge is rotating, determining a weight of material collected within the collection region based on a measured deflection of the movable membrane and based on a rotation speed of the centrifuge.