Apparatus, system, and method for the recovery of fine heavy minerals

Abstract

A method, system, and apparatus for recovering fine heavy minerals from particulate ore. At least two inclined recovery surfaces are provided for parallel operation, and a liquid slurry containing the heavy minerals is supplied to at least one of the surfaces to remove the heavy minerals from the slurry in a heavy minerals capture cycle. In a cleaning cycle, the heavy minerals are released from the at least one surface for collection, which release is preferably achieved by applying water jets which may be disposed on spray bars positioned along the length of the surface and may be applied sequentially to drive the heavy minerals toward a discharge end for collection. A valve arrangement allows the liquid slurry to engage one surface for the heavy mineral capture cycle, while diverting the liquid slurry away from another surface to allow the cleaning cycle, and the valve arrangement may be automatically controlled.

Description

[0001] APPARATUS, SYSTEM, AND METHOD FOR THE RECOVERY OF

[0002] FINE HEAVY MINERALS

[0003] TECHNICAL FIELD

[0004] This invention relates to an apparatus, system, and method to be used in mining, and more particularly to the recovery of fine heavy minerals, including fine gold, from mineral slurry streams.

[0005] BACKGROUND OF THE INVENTION

[0006] Various mechanical procedures have been used and proposed for the purpose of recovering fine heavy minerals. A common method, particularly for gold, is the use of a sluice. Traditional sluices are generally wood or metal troughs constructed with cross bars or riffles which allow heavy minerals to be trapped against the riffles. Underneath or between the riffles, expanded metal and / or a variety of mats or carpets are used to help capture and hold the target minerals. Heavy minerals are captured due to the difference in density of gangue (waste) minerals versus the targeted heavy minerals. The actual recovery mechanisms are complex: One of the key mechanisms is that the riffles introduce concentration vortices in the slurry, wherein heavy minerals are driven into the bed of the sluice, directed by centrifugal and gravitational forces. Sluices require batch operations - after a set period, usually lasting hours, feed to the sluice must be stopped. The riffles, mats, and / or other capture media must then be disassembled and washed to remove and recover the trapped heavy minerals. Sluices can range between 5 feet and 100 feet in length, with a slope between 5° and 15°. Sluice feed capacity is driven by its width, which can be as small as a few inches to several feet wide.

[0007] A similar traditional method of recovering heavy minerals from fine slurry is the strake, with fine slurry defined herein as a mixture of water and mineral particles generally less than 150 microns in size. A strake is a shallow sloping trough with a textured surface, such as blankets, corduroy, carpet, canvas, or like material. All these materials act similarly to riffles on a sluice, but they have shallower depressions, which are sufficient to hold concentrate against the force of the slurry flowing through the trough, but not deep enough to form much of a bed. Recovery is based both on film sizing and sluicing, depending on the bottom surface and the conditions of operation. Film sizing is a form of gravity concentration driven by the difference in resistance to the scouring action of the feed slurry to particles of a similar size with different specific gravities. Strokes traditionally ranged between 5 feet and 50 feet long, with a slope between 5° and 10°. Various efforts have been made to improve and / or automate strokes, such as H.P. Holland’s ore concentrator, disclosed by US patent 416,704 in 1889, G.L. Cudner’s ore concentrator, disclosed by US patent 473,449 in 1892, Joseph Dimmick’s ore concentrator, disclosed by US patent 554,914 in 1896, or more recently William Hibbard’s gold and silver separator, disclosed by US patent 4,352,733 in 1982. If the feed material contains a portion of magnetic minerals, a magnetic mat can be used as the surface, as disclosed by US patent 5,927,508 by David Plath in 1997, with the magnetic minerals attaching to the magnetic mat and forming a textured surface.

[0008] While sluices are still often used at placer mines, processing gravels, sluices and strkes are no longer typically used at hard rock mines, having been replaced by more modern methods, such as jigs, centrifugal concentrators, flotation, and / or cyanidation. Key limitations for sluices and strokes are that they have low processing capacities, require a large area of floor space, are batch operations requiring extensive time for cleaning, and which have not been adapted for continuous automated operation in modem processing facilities.

[0009] The terms stroke or sluice as used herein relate to any surface which is inclined from a feed end to a discharge end and includes components thereon arranged such that heavier particles including fine gold are trapped on the surface while tailings pass over the surface to an exit from the surface. The components to provide the trapping action can be any form or combination of textured surface such as blankets, corduroy, carpet, canvas, ribbed rubber mats, fine carpets, or like material.

[0010] SUMMARY OF THE INVENTION

[0011] According to a first broad aspect of the present invention, there is provided a method of recovering heavy minerals from particulate ore, comprising: providing at least two surfaces configured for parallel operation, each of the at least two surfaces inclined from a feed end to a discharge end, each feed end suppliable with a liquid slurry of the particulate ore by means of a valve arrangement, the valve arrangement operable to selectively switch each of the at least two surfaces between a heavy mineral capture cycle and a cleaning cycle; each of the at least two surfaces having components thereon arranged and configured to retain heavier particles including the heavy minerals therein during the heavy mineral capture cycle while the liquid slurry passes over each of the at least two surfaces to the discharge end; whereas in the cleaning cycle, periodically halting supply of the liquid slurry to the feed end using the valve arrangement thereby allowing for extracting the heavy minerals from the components; wherein the valve arrangement is operable to switch at least one of the at least two surfaces to the heavy mineral capture cycle while keeping at least one other of the at least two surfaces in the cleaning cycle, thereby providing continuous heavy mineral recovery operation by directing the liquid slurry to the at least one of the at least two surfaces operating in the heavy mineral capture cycle while diverting the liquid slurry away from the at least one other of the at least two surfaces operating in the cleaning cycle.

[0012] In some exemplary embodiments of the first broad aspect, the valve arrangement is automatically controlled to switch each of the at least two surfaces between the heavy mineral capture cycle and the cleaning cycle.

[0013] The time period between cleaning cycles for a selected one of the at least two surfaces is preferably in the range of 2 to 8 mins, depending on characteristics of the liquid slurry. The at least two surfaces are preferably stacked to increase throughput capacity.

[0014] In some exemplary embodiments, the at least two surfaces are textured or covered by a textured material that collects the heavy minerals and allows lighter minerals in the liquid slurry to flow over and off the at least two surfaces. The textured material is preferably selected from a group consisting of ribbed rubber mats and fine carpets. Alternatively, the at least two surfaces may be comprised of magnetic mats.

[0015] The discharge end is preferably in fluid communication with a discharge valve arrangement comprising a concentrate control valve and a tailings control valve, wherein in the heavy mineral capture cycle the concentrate control valve is closed and the tailings control valve is open, and wherein in the cleaning cycle the concentrate control valve is open and the tailings control valve is closed.

[0016] In some exemplary embodiments, during the cleaning cycle, the method comprises applying water to the at least one other of the at least two surfaces to drive the heavy minerals out of the components and toward the discharge end. The water is preferably applied by a plurality of nozzles, and the plurality of nozzles may be arranged in an array above the at least one other of the at least two surfaces. Preferably, the plurality of nozzles are disposed in a series of spray bars oriented perpendicular to the at least one other of the at least two surfaces. The series of spray bars may be spaced apart along the entire length of the at least one other of the at least two surfaces. In some preferred embodiments, the plurality of nozzles are actuated sequentially starting at the feed end to drive the heavy minerals toward the discharge end.

[0017] In some exemplary embodiments, the at least two surfaces are arranged to form a rougher and a cleaner, wherein the heavy minerals from the cleaning cycle in the rougher are directed to the cleaner for the heavy mineral capture cycle therein. The liquid slurry exiting the discharge end of the cleaner is then preferably directed to the feed end of the rougher.

[0018] According to a second broad aspect of the present invention, there is provided a system for recovering heavy minerals from particulate ore, the system comprising: a liquid slurry supply for supplying a liquid slurry comprising the particulate ore; at least two surfaces configured for parallel operation, each of the at least two surfaces inclined from a feed end to a discharge end, each feed end in fluid communication with the liquid slurry supply to receive the liquid slurry therefrom by means of a valve arrangement, wherein the valve arrangement is operable to selectively switch each of the at least two surfaces between a heavy mineral capture cycle and a cleaning cycle; and each of the at least two surfaces having components thereon arranged and configured to retain heavier particles including the heavy minerals therein during the heavy mineral capture cycle while the liquid slurry passes over each of the at least two surfaces to the discharge end; whereas in the cleaning cycle, the supplying of the liquid slurry to the feed end is halted using the valve arrangement and water is applied to the components to release the heavy minerals from the components; and wherein the valve arrangement is operable to switch at least one of the at least two surfaces to the heavy mineral capture cycle while keeping at least one other of the at least two surfaces in the cleaning cycle, thereby providing continuous heavy mineral recovery operation by directing the liquid slurry to the at least one of the at least two surfaces operating in the heavy mineral capture cycle while diverting the liquid slurry away from the at least one other of the at least two surfaces operating in the cleaning cycle.

[0019] In some exemplary embodiments of the second broad aspect, the valve arrangement comprises (i) feed valves for supplying the liquid slurry to each feed end of the at least two surfaces, (ii) discharge valves in fluid communication with each discharge end and comprising a concentrate control valve and a tailings control valve, wherein in the heavy mineral capture cycle the concentrate control valve is closed and the tailings control valve is open, and wherein in the cleaning cycle the concentrate control valve is open and the tailings control valve is closed, and (iii) spray valves for applying the water to the components during the cleaning cycle.

[0020] In some exemplary embodiments of the second broad aspect, the valve arrangement is automatically controlled by a control system, the control system programmed and configured to actuate the valve arrangement based on a time elapsed or a feed characteristic such as mass flow.

[0021] According to a third broad aspect of the present invention, there is provided an apparatus for recovering heavy minerals from particulate ore, the apparatus comprising: at least two surfaces configured for parallel operation, each of the at least two surfaces inclined from a feed end to a discharge end, each feed end configured to receive the liquid slurry therefrom by means of a valve arrangement, the valve arrangement operable to selectively switch each of the at least two surfaces between a heavy mineral capture cycle arrangement and a cleaning cycle arrangement; and each of the at least two surfaces having components thereon arranged and configured to retain heavier particles including the heavy minerals therein during the heavy mineral capture cycle arrangement while the liquid slurry passes over each of the at least two surfaces to the discharge end; whereas in a cleaning cycle arrangement, the valve arrangement is configured to halt supply of the liquid slurry to the feed end and water is applied to the components to release the heavy minerals from the components; and whereas in a heavy mineral capture cycle arrangement, the valve arrangement is configured to switch at least one of the at least two surfaces to the heavy mineral capture cycle arrangement while keeping at least one other of the at least two surfaces in the cleaning cycle arrangement, thereby directing the liquid slurry to the at least one of the at least two surfaces operating in the heavy mineral capture cycle arrangement while diverting the liquid slurry away from the at least one other of the at least two surfaces operating in the cleaning cycle arrangement. In some exemplary embodiments of the third broad aspect, the valve arrangement comprises (i) feed valves for supplying the liquid slurry to each feed end of the at least two surfaces, (ii) discharge valves in fluid communication with each discharge end and comprising a concentrate control valve and a tailings control valve, wherein in the heavy mineral capture cycle arrangement the concentrate control valve is closed and the tailings control valve is open, and wherein in the cleaning cycle arrangement the concentrate control valve is open and the tailings control valve is closed, and (iii) spray valves for applying the water to the components in the cleaning cycle arrangement.

[0022] In some exemplary embodiments of the third broad aspect, the valve arrangement is automatically controlled by a control system, the control system programmed and configured to actuate the valve arrangement based on a time elapsed or a feed characteristic such as mass flow.

[0023] BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Embodiments of the invention will be described below in conjunction with the accompanying drawings in which:

[0025] Figure 1 is an isometric view of an apparatus according to the invention, with the surface covered with a textured surface, with a feed distribution system, a spray bar cleaning system, and a discharge.

[0026] Figure 2 is a schematic illustration of a continuous system according to the invention using two parallel surfaces and a cleaning system using water spray nozzles which operate during cleaning cycles, with automated control system components.

[0027] Figure 3 is a perspective view from the rear and one side of a stacked apparatus structure according to the invention.

[0028] Figure 4 is cross-sectional view through the stacked apparatus of Figure 3 according to the invention.

[0029] Figure 5 is a side perspective view of a feed distributor for the apparatus of Figure 3 according to the invention

[0030] Figure 6 is a graph of gold recovery versus surface length.

[0031] Figure 7 is a graph of gold grade versus surface length.

[0032] Figure 8. is a schematic illustration of the system according to the invention using parallel roughers and parallel cleaner surfaces.

[0033] DETAILED DESCRIPTION

[0034] There is provided herein a method of recovering fine heavy minerals, including chromium, copper, gold, iron, lead, nickel, silver, tin, zinc, or platinum group bearing minerals from particulate heavy mineral-bearing ore or a mineral product, such as a mineral processing plant tailings stream.

[0035] A first step of the method, as shown in the schematic of Figure 8 and in the detailed illustrations of an embodiment in Figures 3, 4, and 5, includes creating or collecting a feed supply 80 of a liquid slurry of finely ground particulate heavy mineralbearing ore and directing the feed supply to a rougher feed box 81 , which distributes the feed supply to a parallel series of more than one stacked rougher surface assemblies 83 and 84.

[0036] On each surface body 1 of the stacked assembly 37 (Figures 1 to 5) the liquid slurry of particulate heavy mineral-bearing ore is guided to flow over at least two rougher surfaces 8 which are inclined from a feed inlet 2 to a discharge edge 10. The surfaces are contained in a trough 1 , or the surface body, made of metal, wood, plastic, or other rigid material, with walls high enough to contain the slurry. The body can be of a variety of widths and lengths so that for a rougher surface, a small unit can be around 8 inches wide by 56 inches long. When the slurry enters the feed inlet, it is important to distribute the slurry evenly across the surface 8. This can be done several ways, but typically the system uses a feed distributor 4 which is an angled wear plate that slows down the inlet slurry and spreads it laterally, followed by a bare or smoothly lined portion of the surface, or feed plate 5, which allows the slurry to further distribute across the surface 8.

[0037] The system further includes spray bars 6 which are evenly spaced along the length of the body 1 , with spray nozzles 7 attached to the bars 6. The bar spacing and nozzle spacing are dependent on the type of surface 8 and the mineral composition of the feed. It has been found that a bar spacing of in the range 2 to 8 inches and preferably around 4 inches, and a nozzle spacing of a distance in the range 2 to 12 inches and preferably around 8 inches so as to provide one nozzle per 8 inches of surface width, is generally sufficient. The spray bars 6 are inserted into spray bar openings 9 that are cut into the body 1 . On the bottom of the body 1 , offset spray bar opening covers 15 are provided which allow one body 33 to be placed on top of another body 1 .

[0038] The bodies 1 are arranged such that the feed supply can be selectively fed to at least one of the surfaces and thereby providing continuous operation by installing said at least two surfaces in parallel for example 1 and 24 as shown in Figure 2, with an automated valve arrangement 21 , 22 to divert feed away from a selected one of the surfaces when in the cleaning cycle.

[0039] The body surfaces 8 have a textured surface, such as blankets, corduroy, carpet, canvas, magnetic mat, or like material arranged such that heavier particles including the fine gold are trapped on the surface while tailings pass over the surface to an exit 10 from the surface as tailings. The tailings are collected in a discharge launder 11 and directed to a launder outlet 12. The outlet 12 is attached to a pipe Y-fitting, attached on the other ends to a concentrate automated isolation valve

[0040] 13 and a tailings automated isolation valve 14. Vent holes 3 are provided at the inlet end of each body 1 to ensure an adequate flow of air.

[0041] In a cleaning cycle, the system acts to periodically halt the flow of the slurry, by closing a selected one of the automated valves 21 / 22 to at least one body 1 for extracting the trapped particles, then closing the tailings automated isolation valve

[0042] 14 and opening the concentrate automated isolation valve 13, thus changing the exit from the surface to a location to collect the concentrate. The flow of slurry remains uninterrupted to at least one surface 1 or 24 to maintain continuous operation.

[0043] After the flow is halted to a body 1 , the trapped particles collected on surface 8 are released for collection by applying to the selected surface 8 water jets from the plurality of water spray nozzles 7 on the bars 6 by opening automated water isolation valves 26 to the individual bars 6. Each bar is associated with a respective valve 26 which are operated sequentially, starting at the top of the body 1 so that the spray is sequentially supplied to the surface 8 from the top downward typically with each being turned off as the next is activated. The valves 13, 14, 21 , 22, and 26 may be manually controlled, but this may increase processing time and reduce capacity, and the exemplary embodiment illustrated in FIG. 2 therefore shows a control system 28 configurable for automated actuation of the valves 13, 14, 21 , 22, and 26 (the letter “A” is used to identify automated valves, while the spray valves 26 are identified as solenoid valves). The control system 28 may be a programmable logic controller (PLC) or other suitable automated control unit known to the skilled person. The exemplary control system 28 operates based on inputs from either a common sequence timer, thus actuating the valves based on time period, or alternatively based on a meter 27 “M” measuring one or more feed characteristics of the incoming feed such as but not limited to mass flow.

[0044] In this arrangement the bodies 1 are stacked one on top of another to form the stack assembly 37 to increase feed capacity, reduce floor area, and / or facilitate modular assembly. This is best shown in Figures 3 and 4 where the stacked assembly 37 includes a base frame 36 attaching the stack of surfaces or bodies 1 into a common frame structure and including a stack lid or cover 34 on the top body and a discharge launder cover 35. In this way, the feed control valves 21 ,22, the concentrate control valve 13, the tailings control valve 14, and water spray control valves 26 can be shared between all stacked surfaces. The bodies 1 are constructed such that the spray bar openings 9 on the top of a lower body 1 interlock with the spray bar opening cover 15 on the bottom of an upper one of the bodies, allowing the top body 33 to fit tightly over the next body 1 as shown in Figure 3. This stacked arrangement requires a stack feed splitter 31 placed on top of the stack assembly. The stack feed distributor is fed by a hose inserted into the stack feed inlet 30. The feed slurry enters a feed distributor chamber 40 (Figures 4 and 5) and is forced into a stack feed distributor 41 , prior to entering the feed splitter which defines a series of channels 31 . The feed splitter 31 has several chambers or channels leading to the stack feed splitter discharge nozzles 38, which are connected to the top of the stack feed hoses 32. The stack feed hoses 32, direct the split slurry to the body feed inlets 2.

[0045] As shown in Figure 8, the concentrate is treated in a similar arrangement on more than one dedicated shorter cleaner surfaces also in a parallel series of stack assemblies 88, 89, to achieve a higher grade of heavy minerals.

[0046] Preferably two or more stack assemblies each are arranged to form the rougher circuit 83, 84 and the cleaner circuit 88, 89, shown in Figure 8, where the rougher concentrate 85 from the rougher circuit are fed to the cleaner circuit and the tailings 91 from the cleaner circuit are returned to the feed box 81 supplying the rougher units 83, 84. In particular, preferably the roughers and cleaners are arranged so as to maximize recovery with length and maximize grade, through cleaning, with a much shorter cleaner surface. In detail, the fresh feed supply of slurry 80 is fed to a rougher feed box 81 , which also receives the cleaner circuit tailings 91 , mixing to form a combined rougher feed slurry 82. The rougher feed slurry 82 is fed to more than one rougher stack 83,84 by pump or gravity. Each rougher stack has a feed control valve 21 ,22, to control if the stack is receiving feed or if feed is halted to the stack to allow for automated cleaning with water spray control valves 26. While a rougher stack is being fed 82, heavy mineral concentrate 85 is collected on all the body surfaces 8 and the tailings 86 flows out of the circuit through the discharge launder 11 and through the open automated tailings valve 14. When a rougher feed stack enters a cleaning cycle, the feed control valve 21 or 22 closes, stopping rougher feed slurry 82 from entering the stack, automated tailings valve 14 closes and automated concentrate valve 13 opens. Spray water 25 flows through the water spray control valves 26 through the spray bars 6 and spray nozzles 7, following the cleaning sequence. The rougher concentrate 85 then flows by gravity or is pumped to the cleaner feed box 87. Similar to the rougher feed box 81 , the cleaner feed box feeds the rougher concentrate 85 to a number of cleaner stacks 88,89, with feed controlled by separate feed control valves 21 ,22. The higher grade heavy mineral cleaner concentrate 90 is collected on all the body surfaces 8 of the cleaner stacks and the cleaner tailings 91 flows to the cleaner discharge launder 11 and the open automated tailings valve 14. The cleaner tailings 91 is then pumped or flows by gravity back to the rougher feed box. Using a similar cleaning cycle to the rougher stacks, the cleaner concentrate is pumped or flows by gravity out of the circuit as a final product or to the next stage of processing during cleaning cycles. Optimum feed rates and feed slurry densities depend on the feed material. Optimum valuable heavy mineral recoveries were typically with surfaces 8 approximately 48” long, but for some minerals the surface length could range from 24” to 96” long or longer, as shown in the graph of Figure 6.

[0047] The highest heavy mineral grades are generally in the first 6 to 12 inches of the surface 8, as shown in the graph of Figure 7. In one embodiment of a rougher- cleaner arrangement, the rougher surfaces 8 are 48” long and the cleaner surfaces 8 are 12” long, however, these can be adjusted to suit the feed material.

[0048] The heavy mineral concentrates can be removed with water sprays 7, as opposed to manually cleaning the surface. This allows the system to automate cleaning the concentrate. The water sprays 7 are turned on or off by automated water isolation valves 26. The spray nozzles can be sequenced to control concentrate grade and recoveries, as well. Depending on the feed material, after the feed automated isolation valve 21 is closed, the initial sprays can wash the collected concentrate, removing lightly entrained gangue minerals to the tailings stream. The tailings automated isolation valve 14 is then closed and the concentrate automated isolation valve 13 is opened, and the subsequent spray nozzles are opened in sequence, washing the cleaned concentrate toward the concentrate collection area. The water spray recovery system is suitable to any type of surface 8 that can be spray washed, and can also be used to collect the heavier materials. This may include textured surfaces, ribbed rubber mats, fine carpets, magnetic sheets, etc.

[0049] Preferably the water spray nozzles 7 are arranged in an array over the surface 8 and arranged to direct the water jets onto the surface 8 from above. Preferably the water spray nozzles in the array are operated sequentially starting at the feed end.

[0050] Preferably the water spray nozzles are arranged on a plurality of spray bars 6 at spaced positions along the surface 8. In this arrangement, the spray bars 6 can be spaced by a distance in the range of 2 to 8 inches and preferably around 4 inches. Also, the nozzles 7 can be arranged along the spray bars 6, spaced at a distance in the range of 2 to 12 inches and preferably around 8 inches. The nozzles 7 are typically operated for a time period in the range 1 to 6 seconds and preferably around 2 seconds. The height and angle of the nozzle 7 is selected to achieve effective removal of the concentrate and depends on the type of nozzle, the available water pressure, the type of strake surface selected, and the type of concentrate collected. Generally, a nozzle angle may be in the range of 6 to 10 degrees, and approximately 8 degrees relative to the surface is suitable. The tip of the nozzle 7 may be in the range of 0.75 to 1.25 inches above the surface 8, and preferably approximately 0.9 inches, depending on the spray bar 6 height. The bottom of the spray bar 6 may be 0.5 to 1 inch above the surface 8, and preferably 0.7 inch.

[0051] A continuous feed is supported by placing two or more surfaces 1 in parallel, with an automated feed valve arrangement 21 ,22. Thus, the system feeds to one or more surfaces, while the system cleans a separate one, then alternates. The optimum time required between cleaning cycles depends on the feed rate and the feed material but may be in the range of 2 to 8 minutes. Control may be based on timing, where after a set period of time (2 to 8 minutes), a flush cycle will initiate, although control may also be based on liquid slurry feed rate, slurry density, mineral composition, or any other suitable characteristics. Feed is diverted to a second 84 unit via closing / opening automated feed valves 21 ,22, which are knifegate valves, pinch valves, or similar. After a short period (1 to 10 sec), the concentrate automated isolation valve 13, which may also be a knifegate valve, pinch valve, or similar, opens, and the tailings automated isolation valve 14 (which may also be a knifegate valve, pinch valve, or similar) closes. The automated water isolation valves 26 then open up sequentially for a short time (0.5-6 sec). An additional short period on the order of 2-6 seconds is allowed for the concentrate to drain to the outlet launder 12 and out the concentrate automated isolation valve 13. The concentrate automated isolation valve 13 then closes, and the tailings automated isolation valve 14 opens and the surface 8 is ready to receive feed for the next cycle.

[0052] Feed capacity may be increased by stacking at least two surfaces 1 ,33 on top of another in a stacked assembly 37, where a stack feed splitter 31 is arranged to feed all stacked surfaces from a common supply and wherein tailings valves 13 and concentrate valves 14 are shared between the surfaces. An 8” wide surface optimal feed rate is 50-150 kg / h, depending on the feed material and slurry density. It was found that the minimum height required for a surface body 1 was around 2”. Thus, the bodies can be stacked to significantly increase the capacity. Additional capacity can also be gained by increasing the width of the surface. A single rougher unit 24” wide with 24 separate levels would thus have a feed capacity of 3.6 to 10.8 t / h. A single rougher unit 48” wide with 48 separate levels would have a feed capacity of 14.4 to

[0053] 43.2 t / h. Providing even feed distribution 31 ,41 to each level and across each level 4,5, as described above, helps to achieve desirable performance.

Claims

AMENDED CLAIMS received by the International Bureau on March 28, 2026 (28.03.2026)CLAIMS1. A method of recovering heavy minerals from particulate ore, comprising: providing at least two surfaces configured for parallel operation, each of the at least two surfaces in dined from a feed end to a discharge end, each feed end suppliable with a liquid slurry of the particulate ore by means of a valve arrangement, the valve arrangementoperable to selectively switch each of the at least two surfaces between a heavy mineral capture cycle and a cleaning cycle; each of the at least two surfaces having components thereon arranged and configured to retain heavier particles including the heavy minerals therein during the heavy mineral capture cycle while the liquid slurry passes over each of the at least two surfaces to the discharge end; whereas in the cleaning cycle, periodically halting supply of the liquid slurry to the feed end using the valve arrangement thereby allowing for extracting the heavy minerals from the components; wherein the valve arrangement is operable to switch at least one of the at least two surfaces to the heavy mineral capture cycle while keeping at least one other of the at least two surfaces in the cleaning cycle, thereby providing continuous heavy mineral recovery operation by directing the liquid slurry to the at least one of the at least two surfaces operating in the heavy mineral capture cycle while diverting the liquid slurry away from the at least one other of the at least two surfaces operatingin the cleaning cycle; wherein the discharge end is in fluid communication with a discharge valve arrangement comprising a concentrate control valve and a tailings control valve, wherein in the heavy mineral capture cycle the concentrate control valve is closed and the tailings control valve is open, and wherein in the cleaning cycle the concentrate control valve is open and the tailings control valve is closed.

2. The method according to claim 1 wherein a time period between cleaning cycles for a selected one of the at least two surfaces is in the range of 2 to 8 minutes.

3. The method according to claim 1 wherein the at least two surfaces are stacked.

4. The method according to claim 1 wherein the at least two surfaces comprise magnetic mats or are textured or covered by a textured material that collects the heavy minerals and allows lighterminerals in the liquid slurry to flow over and off the at least two surfaces.

5. The method according to claim 4 wherein the textu red material is selected from a group consisting of ribbed rubber mats and fine carpets.

6. The method according to claim 1 further comprising , during the cleaning cycle, applying water to the at least one other of the at least two surfaces to drive the heavy minerals out of the components and toward the discharge end.

7. The method of claim 6 wherein the water is applied by a plurality of nozzles.

8. The method of claim 7 wherein the plurality of nozzles are arranged in an array above the at least one other of the at least two surfaces .

9. The method of claim 7 wherein the plurality of nozzles are disposed in a series of spray bars oriented perpendicular to the at least one other of the at least two surfaces.

10. The method of claim 9 wherein the series of spray bars are spaced apart along the entire length of the at least one other of the at least two surfaces.

11. The method of any one of claims 8 to 10 wherein the plurality of nozzles are actuated sequentially starting at the feed end to drive the heavy minerals toward the discharge end.

12. The method of claim 1 wherein the at least two surfaces are arranged to form a rougher and a cleaner, wherein the heavy minerals from the cleaning cycle in the rougher are directed to the cleaner for the heavy mineral capture cycle therein.

13. The method of claim 12 wherein the liquid slurry exiting the discharge end of the cleaner is directed to the feed end of the rougher.

14. A system for recovering heavy minerals from particu late ore, the system comprising: a liquid slurry supply for supplying a liquid slurry comprising theparticulate ore; at least two surfaces configured for parallel operation , each of the at least two surfaces inclined from a feed end to a discharge end, each feed end in fluid communication with the liquid slurry supply to receive the liquid slurry therefrom by means of a valve arrangement, wherein the valve arrangement is operable to selectively switch each of the at least two surfaces between a heavy mineral capture cycle and a cleaning cycle; and each of the at least two surfaces having components thereon arranged and configured to retain heavier particles including the heavy minerals therein during the heavy mineral capture cycle while the liquid slurry passes over each of the at least two surfaces to the discharge end; whereas in the cleaning cycle, the supplying of the liquid slurry to the feed end is halted using the valve arrangement and water is applied to the components to release the heavy minerals from the components; and wherein the valve arrangement is operable to switch at least one of the at least two surfaces to the heavy mineral capture cycle while keeping at least one other of the at least two surfaces in the cleaning cycle, thereby providing continuous heavy mineral recovery operation by directing the liquid slurry to the at least one of the at least two surfaces operating in the heavy mineral capture cycle while diverting the liquid slurry away from the at least one other of the at least two surfaces operating in the cleaning cycle; wherein the valve arrangement comprises (i) feed valves forsupplying the liquid slurry to each feed end of the at least two surfaces, (ii) discharge valves in fluid communication with each discharge end and comprising a concentrate control valve and a tailings control valve, wherein in the heavy mineral capture cycle the concentrate control valve is closed and the tailings control valve is open, and wherein in the cleaning cycle the concentrate control valve is open and the tailings control valve is closed, and (iii) spray valves for applying the water to the components during the cleaning cycle.

15. The system of claim 14 wherein the valve arrangement is automatically controlled by a control system, the control system progra mm ed and configured to actuate the valve arrangement based on one or more control characteristics selected from the group consisting of a time elapsed and a feed mass flow.

16. An apparatu s for recovering heavy minerals from particulate ore, the apparatus comprisin g: at least two surfaces configured for parallel operation , each of the at least two surfaces inclined from a feed end to a discharge end, each feed end configured to receive the liquid slurry therefrom by means of a valve arrangement, the valve arrangement operable to selectively switch each of the at least two surfaces between a heavy mineral capture cycle arrangement and a cleaning cycle arrangement; and each of the at least two surfaces having components thereonarranged and configured to retain heavier particles including the heavy minerals therein during the heavy mineral capture cycle arrangement while the liquid slurry passes over each of the at least two surfaces to the discharge end; whereas in a cleaning cycle arrangement, the valve arrangement is configured to halt supply of the liquid slurry to the feed end and water is applied to the components to release the heavy minerals from the components; and whereas in a heavy mineral capture cycle arrangement, the valve arrangement is configured to switch at least one of the at least two surfaces to the heavy mineral capture cycle arrangement while keeping at least one other of the at least two surfaces in the cleaning cycle arrangement, thereby directing the liquid slurry to the at least one of the at least two surfaces operating in the heavy mineral capture cycle arrangement while diverting the liquid slurry away from the at least one other of the at least two surfaces operating in the cleaning cycle arrangement; wherein the valve arrangement comprises (i) feed valves for supplying the liquid slurry to each feed end of the at least two surfaces, (ii) discharge valves in fluid communication with each discharge end and comprising a concentrate control valve and a tailings control valve, wherein in the heavy mineral capture cycle arrangement the concentrate control valve is closed and the tailings control valve is open, and wherein in the cleaning cyclearrangement the concentrate control valve is open and the tailings control valve is closed, and (iii) spray valves for applying the water to the componen ts in the cleaning cycle arrangement.

17. The apparatus of claim 16 wherein the valve arrangement is automatically controlled by a control system, the control system programmed and configured to actuate the valve arrangement based on a time elapsed and / or a feed characteristic such as mass flow.

Images