Patent Publication Number: US-10758912-B1

Title: Material processing system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Not applicable to this application. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable to this application. 
     BACKGROUND 
     Field 
     Example embodiments in general relate to a material processing system for processing material that may include desired rocks and undesired soft material and rocks, as well as pay dirt that contains gold. 
     Related Art 
     Any discussion of the related art throughout the specification should in no way be considered as an admission that such related art is widely known or forms part of common general knowledge in the field. 
     Rock crushers and material processing systems have been in use for many years that separate undesirable rocks and other materials from the rocks that are desirable and in condition for use in concrete. For example, for rock that is to be used in concrete as an aggregate, soft impurities, soft rocks, and irregularly shaped rocks are undesirable, while clean, hard rocks 1″ in size or less, free of coatings of clay or other fine materials, are recommended. Material processing systems have also been used for recovering gold from pay dirt. 
     Current methods may pulverize all the rock instead of just the soft rock and odd-shaped rocks, and so result in the loss of good rock. In addition, further processing, such as water washing, may also be required. 
     SUMMARY 
     An example embodiment is directed to a material processing system. The material processing system includes a base, a table rotationally coupled to the base, a drive assembly coupled to the base by a height-adjustment mechanism, and one or more wheels having an outer surface, the wheels rotationally mounted on the drive assembly and positionable so that a portion of the outer surface of the wheels contacts the table. The table may be rotationally coupled to the base by a bearing, and may further be coupled to the bearing by a table support. 
     The wheels may be pneumatic, and their give may prevent or limit the excessive crushing of the material being processed. The wheel or wheels may be rotationally driven by the drive assembly, and material on the table will be crushed under the wheel as the table rotates. 
     In an example embodiment, the rotation of the driven wheel causes the table to rotate. The height-adjusting mechanism may be fixed, or may be adjustable to increase a pressure between the wheel and the table. For example, the height-adjusting mechanism may comprise a hydraulic cylinder, or if adjustable pressure is not needed (such as for refining/washing gold), the mechanism may be a fixed rod or strut. In the embodiment using a hydraulic cylinder, the hydraulic cylinder may be actuated to forcefully pull the wheels down onto the table, so that when the table rotates under the wheels, material on the table moves under the wheels and is crushed. Adjustment of the downward pressure of the wheels is advantageous because it allows the crushing action to accommodate the type of material being fed to the material processing system, preventing waste that could occur by crushing desirable rock under too much pressure, or under unyielding crushing elements. 
     In an example embodiment, the height-adjusting mechanism may also comprise a double-acting hydraulic cylinder. A double-acting cylinder may be adjustable to lift the wheels off of the table, to allow cleaning, servicing, etc. 
     Example embodiments of the crushing apparatus may further comprise a hopper having a hopper discharge positioned above the table to feed material to the crushing apparatus. The embodiment may further comprise a conveyor having a conveyor discharge, the conveyor discharge positioned above the hopper to supply material, such as unprocessed rock, to the hopper. 
     The apparatus may further comprise a scraper or roller positioned above the table to move the material off the table after it has passed under the wheel or wheels. As mentioned above, the wheel may comprise a plurality of wheels, and one wheel may be driven and other wheels may simply roll on the table as it rotates. The driven wheel or wheels may be rotationally driven by the drive assembly, which may include a gearbox and a motor, wherein the motor drives a wheel through the gearbox. 
     There has thus been outlined, rather broadly, some of the embodiments of the material processing system in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional embodiments of the material processing system that will be described hereinafter and that will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the material processing system in detail, it is to be understood that the material processing system is not limited in its application to the details of construction or to the arrangements of the components set forth in the following description or illustrated in the drawings. The material processing system is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Example embodiments will become more fully understood from the detailed description given herein below and the accompanying drawings, wherein like elements are represented by like reference characters, which are given by way of illustration only and thus are not limitative of the example embodiments herein. 
         FIG. 1  is a perspective view of a material processing system in accordance with an example embodiment. 
         FIG. 2  is a side view of a material processing system in accordance with an example embodiment. 
         FIG. 3  is a top view of a material processing system in accordance with an example embodiment. 
         FIG. 4  is a partial top view of a material processing system in accordance with an example embodiment. 
         FIG. 5  is a partial perspective view of a material processing system in accordance with an example embodiment. 
         FIG. 6  is another partial perspective view of a material processing system in accordance with an example embodiment. 
         FIG. 7  is a partial side view of a material processing system in accordance with an example embodiment. 
         FIG. 8  is a partial side view of a material processing system in accordance with an example embodiment. 
         FIG. 9  a partial side view of a material processing system in accordance with an example embodiment. 
         FIG. 10  is a partial top view of a material processing system in accordance with an example embodiment. 
         FIG. 11  is a perspective view of a material processing system in accordance with another example embodiment. 
         FIG. 12  is a side view of a material processing system in accordance with another example embodiment. 
         FIG. 13  a partial side view of a material processing system in accordance with another example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     A. Overview. 
     An example material processing system  10  generally comprises a base  24 , a table  20  rotationally coupled to the base, a drive assembly  40  coupled to the base  24  by a height-adjustment mechanism  90 , and one or more wheels  30 ,  32  having an outer surface  34 , the wheels rotationally mounted on the drive assembly  40  and positionable so that a portion of the outer surface  34  contacts the table  20 . The table  20  may be rotationally coupled to the base  24  by a bearing  22 , and may further be coupled to the bearing by a table support  28 . 
     Material to be crushed, washed, or otherwise processed by the system  10  will generally be fed to the table  20  by a supply conveyor  50 , either directly or via a hopper  80 . The system can be fed with rock or any material of a desirable size, which can then be crushed or cleaned (e.g., by having softer materials, coatings, etc. removed from the desired end product by being pressed between the outer surfaces  34  of the wheels and the table  20 . After passing under one, two, or more wheels, the processed material can be scraped off the table  20  by a scraper or roller  70 , where it can then drop onto an output conveyor  52  for collection or further processing. 
     In addition to crushing material, the processing system  10  can be used for gold recovery. In such embodiments, the table  20  may comprise a plurality of annular grooves  64 . As the table rotates and material, such as pay dirt, is supplied to the table via a conveyor  50  and, possibly, hopper  80 , water may also be supplied or sprayed onto the table, for example, via a water supply element, such as water supply tube  60 . As the table rotates, the water and pay dirt will be carried over the table  20  from the center to the outer edge, and heavier gold will tend to settle into the grooves  64 , while the much lighter portions of the pay dirt (gravel, soil, minerals, etc.) will wash over the grooves and ultimately off the table  20 . In this embodiment, the wheels  30  and  32 , or at least one of them, may still drive the table, and the wheels will not impede the separation of gold from the pay dirt, although the crushing action of the wheels may not be needed. 
     Because the crushing action may not be needed for gold recovery, the system in some embodiments may comprise a drive motor  44  below the table  20 , supported by a base  24 . In such possible embodiments, the wheels  30  and  32  may not be needed to drive the rotation of table  20 . 
     The wheels  30 ,  32  may be pneumatic, and their “give” may prevent the complete crushing of the material  12  being processed. The wheels  30 ,  32  may be rotationally driven by the drive assembly  40 , and material on the table  20  will be crushed under the wheel or wheels as the table  20  rotates beneath the wheels. The drive wheel  30  will generally cause the rotationally mounted table  20  to rotate underneath the wheels, which may vary in number. 
     In an example embodiment, the rotation of the driven wheel  30  causes the table to rotate. The height-adjusting mechanism  90  may be fixed, as shown in  FIG. 11 , or may be adjustable to increase a pressure between the wheels  30 ,  32  and the table  20 . For example, the height-adjusting mechanism  90  may comprise a simple rod or strut, or it may comprise a hydraulic cylinder  94 , which has a piston  92  coupled or connected to the housing of gearbox  42  of drive assembly  40 . The hydraulic cylinder  94  may be actuated to forcefully pull the wheels down onto the table  20 , so that when the table rotates under the wheels, material  12  fed onto the table moves under the crushing surface  34  of wheels  30 ,  32 , and is crushed. Adjustment of the downward pressure of the wheels is advantageous because it allows the crushing action to accommodate the type of material  12  being fed to the material processing system  10 , preventing waste that could occur by crushing desirable rock under too much pressure, or under unyielding crushing elements (such as hard, non-compliant rollers, etc.). 
     The height-adjusting mechanism  90  may be, for example, a double-acting hydraulic cylinder  94 . In addition to applying large downward forces to the wheels, a double-acting cylinder may be adjustable to lift the wheels off of the table, to allow cleaning and servicing of the material processing system. 
     The material processing system  10  may further comprise a hopper  80  having a hopper discharge  82  positioned above the table to feed material  12  to the crushing system  10 . In this and other embodiments, the system may have a supply conveyor  50  with a conveyor discharge  51 , the conveyor discharge  51  positioned above the hopper  80  to supply material  12 , such as unprocessed rock, to the hopper. 
     The apparatus may further comprise a scraper or roller  70  positioned above the table  20  to scrape or force the material  12  off the table after it has passed under the wheel or wheels. As mentioned above, the wheel may comprise a plurality of wheels  30 ,  32 , and one wheel may be driven and other wheels may simply roll on the table  20  as it rotates. The driven wheel or wheels may be rotationally driven by the drive assembly  40 , which may include a gearbox  42  and a motor  44 , wherein the motor  44  drives one or both wheels through the gearbox  42 . 
     B. Table and Table Support. 
     As best shown in  FIGS. 1-3 , an example material processing system  10  may include a flat table  20  that generally may be a rotating structure, that provides a surface for crushing, refining, or cleaning materials fed to the system. The table  20  may be a relatively thin, flat sheet of material, such as steel, and may further be round, so that the overall shape of the table  20  is that of a disc. However, the table should be thick enough to have considerable strength in order to provide a stable, unbending crushing surface. In one possible embodiment, the table may be circular, and 12 feet in diameter. To aid in rigidity, the table may be securely attached to, and supported by, a table support  28 , as shown in  FIG. 2 , as one possible example. The table support  28  may be engineered for high strength and rigidity, so that the table  20  and support  28  provide a very stable, rigid rotating surface for crushing any material under rotating wheels  30 ,  32 . 
     The table  20  may be generally horizontal, and may further be held in position parallel to, and above, a fixed base  24 , upon which the entire material processing may rest. Alternatively, the table  20  may be tilted if desired, for example, if a user finds it desirable to used water in the crushing/cleaning process to further process or clean the material being fed to the system  10 . If water is used, tilting the table  20  may allow the water to drain off the table surface at a particular location. 
     In other embodiments, the upper surface of the table may not be perfectly flat, but may instead be contoured or shaped to keep any crushed or raw materials under the wheels and away from the center or extreme outside edge of the table, for example. Since they will generally rotate under the wheels, the table  20  and table support  28  may be supported by a large, ring-shaped bearing  22 , which may be similar to the swing bearing of an excavator. The bearing  22  allows the table  20  and table support  28  to rotate freely while still being rotationally coupled to a stable base  24 , which supports the bearing  22  and the entire material processing system  10 . 
     The table  20  may also include a central opening  26 . As shown in  FIGS. 5 and 8 , a height-adjusting mechanism  90 , such as a hydraulic cylinder  94 , may extend upwardly through the central opening  26 . The central opening  26  allows the height-adjusting mechanism  90  to support the wheels and drive assembly, as well as other structures, above the table  20 . Because the height-adjusting mechanism  90  is not attached to the table  20  or the table support  28 , it does not necessarily rotate with the table  20 . Height-adjusting mechanism  90  may be mounted securely, such as by welding, to the base  24 . The height-adjusting mechanism  90  may be used to adjust the height of wheels  30 ,  32  above the table  20 , if necessary, while the table  20  has a fixed position and distance above the base  24 . 
     In still other embodiments, the upper surface of the table may include a plurality of annular grooves  64 , which may be useful for washing gold out of pay dirt, as shown, for example, in  FIGS. 11 and 13 . In an example embodiment, the grooves may be square in profile and may further be about ½ inch deep and be spaced about 3 inches apart along the surface of table  20 . It will be appreciated, however, that these dimensions are not necessarily critical, and other groove profiles may be used to catch gold. In this embodiment, conveyor  50  and hopper  80  may be positioned closer to the center so that pay dirt will be washed over more of the annular grooves  64 , as shown in  FIGS. 11 and 13 . As the table rotates and material, such as pay dirt, is supplied to the table via conveyor  50  and, possibly, hopper  80 , water may also be supplied or sprayed or poured onto the table, for example, via water supply tube  60 . A collar  62 , which may be in the form of a hollow tube, can be used to prevent water from entering the central opening of the table in some embodiments. 
     As the table rotates, the water and pay dirt will be carried over the table  20  from the center to the outer edge, due to the table&#39;s rotation, and the heavier gold will tend to settle into the grooves  64 , while the much lighter portions of the pay dirt (gravel, soil, minerals, etc.) will be washed over the grooves by the water and ultimately carried off the table  20 . 
     In one possible embodiment including annular grooves (e.g., as shown in  FIG. 11 ), the wheels  30  and  32 , or at least one of them, may still drive the table, and the wheels will not impede the separation of gold from the pay dirt, although the crushing action of the wheels may not be needed. Further, in this embodiment, the height-adjusting mechanism  90  may not need to vary the distance, or apply varying force, between the wheels  30 ,  32  and the table  20 ; accordingly, the mechanism  90  may be a simple structure, such as a rod or strut. 
     Because the crushing action may not be needed for gold recovery, the system in some embodiments may comprise a drive motor  44  below the table  20 , supported by a base  24 , as shown in  FIG. 13 . In such possible embodiments, the wheels  30  and  32  are not needed to drive the rotation of table  20 . 
     C. Wheels. 
     As best shown in  FIGS. 1-3 , an example material processing system  10  may also include one or more wheels, for example, two wheels  30 ,  32 . As shown, the wheels may be large, pneumatic wheels with a substantially flat surface  34  for crushing material  12  between the wheels and the table  20 . In an example embodiment, the wheels may be or comprise two 6-foot diameter, 30″ wide rubber wheels set atop table  20 , rotating in opposite directions. In one possible example embodiment, wheel  30  may be a drive wheel that is driven by drive assembly  40 , while wheel  32  may be a non-driven wheel that is mounted on the same axis as wheel  30 , but as indicated, is not driven by drive assembly  40 . This example configuration may be desirable and easier to implement than others, since the two wheels will rotate in different directions as the table  20  rotates under them. Thus, drive wheel  30  itself causes table  20  to rotate on its bearing  22 , due to its contact with the table. 
     Wheel  32 , in turn, may be driven by the table  20  rotating beneath it, again due to contact between the surface  34  of wheel  32  with the top of the table. Material, such as unprocessed rock, to be crushed, can be fed onto table  20  directly in front of either wheel  30  or  32 , since either wheel will perform the function of crushing and cleaning the material. The system  10  can be generally configured so that material will pass under two wheels, as best shown in  FIG. 3 , before scraper/roller  70  forces it onto output conveyor  52  after it has been processed. An embodiment with a scraper is shown in  FIGS. 2 and 3 , and an embodiment with a roller  70  is shown in  FIG. 12 . 
     As also shown in  FIG. 3 , wheel  30  can be driven by drive assembly  40 . The drive assembly  40  may comprise a motor  44 , which may be a hydraulic motor, although an electric motor may also be used. If a hydraulic motor  44  is used, it may be supplied with hydraulic power by hydraulic lines  48 . The drive configuration is also shown in  FIG. 6 , which illustrates how hydraulic lines  48  can be routed to the motor  44  between the wheels, which is an advantage of the wheels being stationary as shown, while the table  20  rotates about a vertical axis under the wheels.  FIG. 6  also shows how the height adjusting mechanism  90 , specifically comprising cylinder  94  and piston  92  in this example embodiment, support and serve as a secure mount for the gearbox  42  as well as the wheels  30  and  32 . 
     As mentioned above, it is possible for the hydraulic motor to be coupled to wheel  30  through a gearbox or differential  42 , which may drive the single wheel  30 . Gearbox  42  may be coupled at its lower side or end to piston rod  92  of hydraulic cylinder  94 . Thus, hydraulic cylinder  94  and piston rod  92  can comprise height-adjusting mechanism  90 , which controls the height, and accordingly the pressure, of wheels  30 ,  32  above the upper surface of table  20 . Cylinder  94  can be a double-acting cylinder, and can be large, capable of applying 130,000 pounds of downward force, or more, to drive assembly  40 , to create large crushing forces applied by the wheels  30 ,  32 . 
     D. Height-Adjusting Mechanism. 
     As best shown in  FIGS. 5 and 7-9 , an example material processing system may include a height-adjusting mechanism  90 . As shown, one possible embodiment of the mechanism is a double-acting hydraulic cylinder  94 . As also shown in  FIG. 8 , the base end of cylinder  94  may be securely attached to base  24 , in the center of the material processing system  10 . The cylinder  94  may be welded or bolted to the base  24 , and may extend through the center of bearing  22 , and through the open center of table support  28  and the central opening  26  of table  20  (see also  FIG. 5 ). Since the cylinder  94  is solidly mounted to the base  24 , and since it does not rotate along with table  20  during operation, the cylinder  94  may also be used as an attachment point for scraper or roller  70  and also hopper  80 , although those components may also be secured to a structure or structures beyond the outer edge of table  20  if desired or necessary. 
     As an example, a support arm  100  may be welded, bolted, or attached by other means to cylinder  94 , and can in turn hold scraper/roller  70  in a desired position in contact with table  20 , so that, as table  20  rotates, crushed rock that has passed under wheel  32  ( FIG. 3 ) is forced off the table  20  and onto output conveyor  52  for screening, storage, etc. The scraper  70  may be offset from, and attached to, the support arm  100  by struts  102 , as also shown in  FIG. 3 . The scraper or roller  70  may be mounted so that its position, angle, and height can be adjusted as desired, with respect to the surface of table  20 . 
     In order to stabilize and maintain a constant pressure and thus grinding force, cylinder  94  may be supplied with hydraulic pressure via a hydraulic accumulator  46 , which, as is known, can reduce or eliminate pressure variances in hydraulic lines, such as lines  48 , due to fluctuations at the source. In order to create large forces if necessary, the height-adjusting mechanism, and specifically cylinder  94  and piston rod  92 , are attached to the drive mechanism  40  via gearbox  42 , and can create tremendous downward pressure if needed. For example, it is possible for cylinder  94  and piston rod  92  to pull gearbox  42  down toward table  20  with as much as 130,000 pounds of force or more. This force is adjustable, which allows the crushing action of the system  10  to also be adjusted depending on the material being processed and the desired results. 
     In addition to supplying downward force, the mechanism  90  can also be used to raise the wheels and the drive assembly  40  a substantial height above their normal operating position as shown in  FIG. 9 , which allows for access to the wheels and table  20  for cleaning, maintenance, etc. 
     If two or more wheels are used, it can be readily seen that a balanced, downward crushing force will be applied by each wheel due to the height-adjusting mechanism being located in the center, or approximate center, of the wheels. Further, use of multiple wheels may prevent an uneven load from being applied to the bearing  22 , which might otherwise cause it to wear prematurely. 
     E. Operation of Preferred Embodiment. 
     In use, the material processing system  10  may be located on-site where rock or other material is to be processed. One possible use of the system is to crush or otherwise process rock or material  12  to be used as an aggregate in the concrete industry. As discussed further below, another use of the system is gold recovery—separating gold from pay dirt. Use of the system allows impurities to be removed from the desired rock. Using rubber, pneumatic wheels in contact with metal allows for the elimination of soft rock and impurities from the rock without further crushing rock that is already of desirable size and hardness. This is possible by adjusting the downward pressure applied by the wheels to the material  12  between the wheels and the table  20 , and also because of the compliance or give of the rubber, pneumatic tires. Thus, the system reduces the loss of hard rock and eliminates the soft, undesirable rock, irregularly shaped rock, and other materials from the final product. 
     Material  12  to be processed by the system is first fed to the table  20  just in front of wheel  30  or  32 . The material may be fed directly by a conveyor  50  having a discharge end  51 , or alternatively, the discharge end  51  of the conveyor may be positioned over the open end of hopper  80 , as shown in  FIG. 1 , which has a hopper discharge  82  to drop material  12  in front of wheel  30  or  32 , onto table  20 . The hopper discharge  82  may be a simple, fixed opening at the bottom of the hopper, or it may be a slide gate, which would allow for some regulation of the rate at which material  12  is fed into the system, in addition to the rate controlled by the speed at which conveyor  50  is run. 
     Once the material  12  is dropped in front of wheel  30 , the rotation of the table toward the wheel carries it under the wheel, where the material  12  is between the outer surface  34  of wheel  30  and the top surface of table  20 . Due to the downward force of the wheels  30  and  32 , the material  12  is crushed between the compliant wheels and the table. As shown in  FIG. 4 , the normal path of a point on the table  20  differs from the centerline of wheel  30 . The same is true for wheel  32 . In other words, because the path denoted in  FIG. 4  is not linear, the crushing action differs from that of a wheel simply rolling over a rock on a stationary surface, such as a rock on a road. Instead, a scrubbing action is introduced, which aids the crushing process. Upon observing the crushing process and the processed material, the downward pressure of the wheels on the table can be adjusted by changing the hydraulic pressure supplied to cylinder  94  via hydraulic accumulator  46 , so that the rock is not crushed too much, which can result in loss of good, hard rock of proper size. 
     The crushing process, again with the compliant wheels  30 ,  32  and the scrubbing action, tends to crush any soft rock that is mixed in with the desired rock, which may be suitably hard rock such as rock 1″ or smaller in its largest dimension. Softer materials such as shale, iron oxide, coal, soft particles, and other material, as well as soft material on the surface of hard rocks, is eliminated by the crushing system  10 . In addition, elongated pieces of rock will be crushed due to their shape. These soft materials or elongated pieces are considered to be impurities, and are undesirable, for material used as an aggregate in concrete, for example, although other uses for the material processing system are possible as well. By not over-processing the material, loss of good rock can be reduced or eliminated. Furthermore, use of the material processing system  10  may eliminate or reduce the need for further processing of the rock, such as using a wash plant in addition to pulverization, and the need to run material through a jig after a wash plant is used. 
     Once material  12  has passed under wheel  30 , it continues to move around the rotating table  20  until it reaches wheel  32 , where it undergoes further crushing, with the same effect as discussed above, further crushing soft materials and cleaning the hard rock of any substance on its surface. As the material  12  emerges from under wheel  32 , it will typically be a mixture of gravel and powder, dust, etc. The material at this point will be carried by the table&#39;s rotation into contact with scraper/roller  70 , which may be positioned at an angle to the natural path of the material on the table surface, so as to urge the material toward the outside edge of the table  20 , and eventually, off the edge. 
     As shown in  FIG. 10 , the scraper or roller  70  may be mounted on the cylinder  94  via a support arm  100  and struts  102 . If a roller  70  is used, it may be mounted with pivots on its ends (not shown). Since cylinder  94  does not move vertically or rotate, it can provide a stable base above table  20  for mounting the scraper/roller  70 , hopper  80 , support arm  100 , etc. Further, because the table  20 , rather than the wheels, rotates about a central vertical axis, hydraulic lines and any other equipment can reach the central portion of the material processing system between the wheels, as needed, without interference from wheels moving around the table. 
     After crushing, the material  12  can be allowed to fall off the edge of table  20  and into a pile, or it can be run through one or more screens to separate it by size—for example, to allow dust and smaller particles to fall through a screen while the larger pieces pass over the screen. As shown in  FIG. 3 , before it is separated, all the material can simply be urged off of the table  20  and onto the top surface of an output conveyor  52  for further processing (e.g., separation by size) or simply piling near the conveyor discharge. 
     As mentioned above, the material processing system  10  may be used for gold recovery—separating gold from pay dirt, rather than crushing and separating rocks from softer materials. In such example embodiments, the upper surface of the table may include a plurality of annular grooves  64 , as shown, for example, in  FIGS. 11 and 13 . In an example embodiment, the grooves may be square in profile and may further be about ½ inch deep and be spaced about 3 inches apart along the surface of table  20 , although these dimensions are not necessarily critical, and other groove profiles may be used to catch gold. In this embodiment, conveyor  50  and hopper  80  may be positioned closer to the center of the table  20  so that pay dirt will be washed over more of the annular grooves  64 . Water may also be supplied or sprayed onto the table, for example, via water supply tube  60 , the water being used to wash and separate lighter material from the gold, which will tend to fall into the annular grooves, and stay there. A collar  62 , which may be in the form of a hollow tube, can be used to prevent water from entering the central opening of the table in some embodiments. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar to or equivalent to those described herein can be used in the practice or testing of the material processing system  10 , suitable methods and materials are described above. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety to the extent allowed by applicable law and regulations. The material processing system  10  may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive. Any headings utilized within the description are for convenience only and have no legal or limiting effect.