Abstract:
A mining apparatus and method of its use are disclosed. The apparatus includes a heavy metals separating subsystem and a water recycling subsystem. The heavy metals separating subsystem includes one or more classifying screens positioned to receive raw mining material classify materials to a pre-determined size, a slurry tank receiving water and the classified materials, forming a slurry, and a heavy metals concentrating assembly configured to receive the slurry and separate heavy metals from the slurry. The water recycling subsystem is positioned to receive the tailings and separate the tailings into recyclable water and solid waste. The water recycling system is configured to route the recycled water into the heavy metals separating subsystem for reuse.

Description:
BACKGROUND 
       [0001]    Mining systems, and in particular mining systems designed for heavy or precious metals, generally include many large-scale systems and subsystems used to classify and process various sediment types, thereby extracting the heavy or previous metals from sediment. Such mining systems generally require use of a substantial amount of water with which sediments are separated from heavy or previous metals. This water is generally retrieved from a nearby water source, such as a lake or river. Once used in the heavy metal extraction process, the now sediment-filled water is stored in settlement pools near the mining operation, which allow the sediments discarded as part of the mining process to separate from the water. Once the sediments and water separate, the water can then be returned to the water source. 
         [0002]    These existing mining systems have numerous drawbacks. First, such a system can be difficult to transport, particularly to a location which is not readily accessible by heavy machinery. Second, such a system generally requires a large environmental footprint. That is both because of the size of the equipment used as well as the size of the sediment pools required to allow for settlement of sediments out of the water. Furthermore, such systems require a large volume of water to perform the heavy metal extraction process. 
         [0003]    The above disadvantages of existing mining systems lead them to be unsuitable for use in many locations. For example, in particularly arid conditions, there may be only a limited water source, which is otherwise incapable of providing sufficient water for mining operations. Furthermore, in part due to the environmental impact of existing mining operations, many states, such as Nevada, California, and Arizona, as well as other international jurisdictions, restrict mining operations in particular areas (or overall). For example, many states are trying to mitigate potential environmental damage done by large mining equipment and potential groundwater contamination from large sediment pools and the protection of fish habitats due to suspended particulate in streams and rivers, and to conserve water. Accordingly, areas exist which may have substantial or economic heavy or precious metal deposits, but are unavailable for mining purposes due to difficulty in transporting mining equipment, lack of a convenient water source, or environmental regulations restricting the footprint of a mining operation. 
         [0004]    It is with respect to this general environment that the embodiments of the present application are directed. 
       SUMMARY 
       [0005]    In summary, the present disclosure relates to a mining apparatus with an integrated water reclamation system, as well as a process for its use. In some of the various embodiments discussed herein, the mining apparatus can be transported to and used in remote locations where transport, water supply, or environmental restrictions would otherwise prohibit mining operations, since many of the impacts of such typical mining operations are avoided. 
         [0006]    In a first aspect, a mining apparatus includes a heavy metals separating subsystem. The heavy metals separating subsystem includes a classifying screen positioned to receive raw mining material and sized to separate particles above a predetermined size from classified materials. The heavy metals separating subsystem also includes a slurry tank receiving water and the classified materials, forming a slurry, and a heavy metals concentrating assembly configured to receive the slurry and separate heavy metals from the slurry. The mining apparatus also includes a water recycling subsystem positioned to receive the tailings and separate the tailings into recyclable water and solid waste. In some cases, the water recycling system is also configured to provide a secondary heavy metals separation with a centrifugal filtration system. 
         [0007]    In a second aspect, a method of mining for heavy metals is disclosed. The method includes receiving raw mining materials at a mining apparatus, and classifying the raw mining materials to obtain classified materials below a predetermined size. The method further includes the fluidization of the material by mixing with water to form a slurry of the classified materials. This slurry is subsequently pumped through hydroclones to reduce the solids by weight and then into a gravimetric separator to separate the slurry into heavy metals and tailings. The method includes routing of the tailings through a hydrocyclone and one or more screens, to dewater to separate the solids from the tailings. The method further includes routing the tailings water to one or more mixing tanks to combine the tailings water with a clarifying agent, and into one or more clarification tanks to further separate suspended solids from the tailings water to produce clarified waste water and solid wastes. The method also includes the further filtering of the clarified waste water, and re-introducing the filtered waste water into the mining apparatus for reuse In some cases, the remaining suspended solids from the clarifiers are pumped through a filter press for the further extraction of water producing an almost dry filter cake. 
         [0008]    In a third aspect, a portable mining apparatus includes a heavy metals separating subsystem mounted to a portable trailer. The heavy metals separating subsystem includes a hopper to receive the material to premix with water, a heavy metal pre-separation device, a rotating trommel for fluidization and pre-classification, and a classifying screen positioned to receive pre-classified mining material and sized to separate oversize particles from classified materials below a predetermined size, and a slurry tank receiving water and the classified materials, forming a slurry. The heavy metals separating subsystem also includes a heavy metals concentrating assembly configured to receive the slurry and separate heavy metals from the slurry and ejecting the remainder of material as waste tailings. The apparatus also includes one or more waste tanks positioned to receive the waste tailings. The apparatus further includes a water recycling subsystem mounted on a portable trailer to receive the contents of the one or more waste tailings tanks and separate the contents into recyclable water and solid waste. The water recycling subsystem includes one or more mixing tanks receiving the contents of the one or more waste tanks, and a clarifier positioned to add a clarifying agent to the one or more mixing tanks to assist in separating the contents of the one or more mixing tanks into clarified waste water and solid wastes. The water recycling subsystem also includes a filter press receiving settled waste water from one or more mixing tanks receiving settled waste water from the one or more waste tanks and separating the settled waste water into water and dry waste, and one or more balance tanks receiving the water from the filter press and the clarified waste water, the one or more balance tanks fluidically connected to a disk filter and cooperating with the disk filter to provide filtered water that is reintroduced into the heavy metals separating subsystem. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a general-purpose block diagram of a portable mining apparatus according to an example embodiment of the present disclosure; 
           [0010]      FIG. 2A  is a logical diagram illustrating a portable mining apparatus according to an example embodiment of the present disclosure; 
           [0011]      FIG. 2B  is a logical diagram illustrating a portable mining apparatus according to an example embodiment of the present disclosure; 
           [0012]      FIG. 3  is a block diagram illustrating a general progression of mining materials and water through a portable mining apparatus; 
           [0013]      FIG. 4  is a flowchart illustrating a method of mining for heavy metals, according to an example embodiment; and 
           [0014]      FIG. 5  is a perspective view of an example portable mining apparatus illustrating a possible layout of mining equipment on a vehicle-portable platform, according to one possible embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    As briefly described above, embodiments of the present invention are directed to a mining apparatus with an integrated water reclamation system, as well as a process for its use. In the various embodiments discussed herein, the portable mining apparatus can be transported to and used in remote locations where transport, water supply, or environmental restrictions would otherwise prohibit mining operations, since many of the impacts of such typical mining operations are avoided. 
         [0016]    In accordance with the present disclosure, a general block diagram of an example portable mining apparatus  100  is illustrated in  FIG. 1 . As illustrated, the portable mining apparatus  100  generally includes a heavy metals separating subsystem  102  and a water reclamation subsystem  104 . The heavy metals separating subsystem  102  generally receives raw mining materials as well as water from a water supply, and includes one or more components useable to separate heavy or precious metals from the raw mining materials, for example using systems including water. In particular, the heavy metals separating subsystem  102  can be configured to extract any of a variety of types of desirable heavy metals, including previous heavy metals such as gold or silver. In particular, in the embodiment shown, the heavy metals separating subsystem  102  outputs solid waste and heavy metals as well as a waste water and tailings mixture. Traditionally, such a mixture would be stored in settling ponds, allowing the sediment to precipitate out of the water prior to re-introducing the water back to the water source for the overall mining apparatus. 
         [0017]    The heavy metals separating subsystem  102  is, in some embodiments, configured to be mountable to a vehicle-portable platform, such as a flatbed trailer capable of being towed by a vehicle to a mining site. One example of such a subsystem is illustrated in  FIG. 2A , below, with a layout of components of such a subsystem illustrated in  FIG. 5 , below. 
         [0018]    The water reclamation subsystem  104  is configured to be integrated with the heavy metals separating subsystem  102 , and generally designed to receive tailings and waste water that would otherwise be placed into settling ponds to allow separation of sediments from water. The water reclamation subsystem  104  instead receives the tailings and waste water for treatment, and processes the tailings and waste water to allow for reuse of water within the heavy metals separating subsystem  102 . In example embodiments, the water reclamation subsystem  104  is also portable, and mountable to a vehicle-portable platform (the same platform or a different one from the heavy metals separating subsystem  102 ). Furthermore, the water reclamation subsystem  104  can include various components including separators, filters, and/or clarifying processes, for separating reclaimed water from solid waste removed from the tailings and waste water. One example of such a subsystem is illustrated in  FIG. 2B , below. 
         [0019]    Referring now to  FIGS. 2A-2B , a logical diagram illustrating a portable mining apparatus  200  is illustrated, according to a particular embodiment of the present disclosure. The portable mining apparatus  200  as shown can be, in some embodiments, a particular implementation of the apparatus  100  of  FIG. 1 .  FIG. 2A  illustrates a possible embodiment of a heavy metals separating subsystem  210 , which can represent a possible arrangement of the heavy metals separating subsystem  102  of  FIG. 1 , while  FIG. 2B  illustrates a possible embodiment of a water reclamation subsystem  250 , which can represent a possible arrangement of the water reclamation subsystem  104  of  FIG. 1 . 
         [0020]    Referring to  FIG. 2A  specifically, the heavy metals separating subsystem  210  receives, in the embodiment shown, raw mining materials can first be classified using a grizzly (not shown) to arrive at mining particles below a first predetermined size, such as 1-3 inches in diameter. The mining materials below this size can be placed into a hopper  211 . At the hopper  211 , water is introduced to fluidize the mining materials. In an example embodiment, the mining materials can be routed to the hopper at a relatively high rate; for example, in a particular embodiment, the hopper can accept 20 tons per hour of raw mining materials, as well as 100 gallons of water per minute to fluidize the raw mining materials. From the hopper, materials larger than the predetermined size are discarded to a solid waste pile  212 . 
         [0021]    Materials from the hopper  211  are passed to a fluidizing trommel  214 , which receives water from either a water source (not shown), or from a water reclamation subsystem, such a subsystem  250  discussed below and shown in  FIG. 2B . The fluidizing trommel  214  receives additional water, for example a constant flow of about 80 gallons per minute, to assist in separating materials. The fluidizing trommel  214  separates the raw mining materials in a variety of ways. Solid waste, corresponding to materials greater than a second, smaller diameter (e.g., about 10-13 mm) is routed to a solid waste pile  212 . Oversized heavy metals, caught by an oversize heavy metal trap  215 , are caught and routed to a sorting table  213 , such as a “gold table”. Additionally, materials smaller than the second diameter are routed to a classifying screen  216 . 
         [0022]    At the classifying screen  216 , still further separation of materials according to size is performed. For example, the classifying screen can separate materials greater than about 2 mm in diameter to be routed to the solid waste pile  212 , while allowing smaller materials to pass into an ore slurry tank  218 . The classifying screen  216  receives additional water to assist in the classification, but generally requires less water than the fluidizing trommel  214 , for example about 10 gallons per minute, to form the slurry passing into the ore slurry tank  218 . 
         [0023]    From the ore slurry tank  218 , a pump  219  routes a slurry at a high rate of throughput to a hydrocyclone  220 , which increases the volume by weight of suspended particulate matter. The underflow from the hydrocyclone  220  is routed to a gravimetric separator  222 , while the overflow is passed to a tailings tank  224 . The gravimetric separator  222  receives the output of the hydrocyclone  220 , as well as additional water, and extracts heavy metals from the slurry, passing the extracted heavy metals to a heavy metals concentration tank  227 , and to the sorting table  213 . Tailings from the gravimetric separator  222  are passed into the tailings tank  224 . 
         [0024]    From the tailings tank  224 , a pump  225  routes tailings to a further hydrocyclone  226 , while additional or overflow tailings are routed to a waste tank  228 . Likewise, and referring back to the ore slurry tank  218 , overflow from that tank can be routed to a waste tank  230  as well. The waste tanks  228 ,  230  are emptied by pumps  229 ,  231 , respectively to one or more buffer tanks included in a water reclamation subsystem  250  of  FIG. 2B , discussed below. Meanwhile the hydrocyclone  226  is used to again increase volume by weight of suspended particulate, prior to passing the tailings through a parabolic screen  232 , and overflow to a dewatering tank  234 . The parabolic screen  232  may also receive tailings from additional hydrocyclones  236   a - b , and the tailings are pumped via pump  235  from the dewatering tank  234 . A further dewatering vibrating screen  238  receives the output of the parabolic screen  232 , and, when additional spray water is applied, separates tailings from solid waste, which is routed to the solid waste pile  212 . Additionally, the dewatering tank  234  receives the output of the dewatering vibrating screen  238 , thereby forming a cycle of water continuously screening and routing tailings to the dewatering tank  232 . A pump  233  routes the screened tailings to a water reclamation subsystem  250 . 
         [0025]    Referring to  FIG. 2A  overall, it is noted that the heavy metals separating subsystem  210  includes a number of components requiring a water source. In the context of the present disclosure, the heavy metals separating subsystem  210  can use a stand-alone water source in conjunction with a water reclamation subsystem, or can alternatively operate for at least some time using the water reclamation subsystem alone. As seen in  FIG. 2B , the water reclamation subsystem  250  receives waste water (including tailings, etc. from the waste tanks  228 ,  230  at buffer tanks  252   a - b , and also receives water from a dewatering tank  232  at a turbidity meter  254 . The turbidity meter  254  routes the water either to a centrifugal filter  256 , and self-cleaning disc filters or sends the waste water to a flocculent injector  258  via a three-way valve  259 . The flocculant injector  258  receives a flocculant from a clarifying system  260 , which transmits a flocculant (clarifying agent) via a flocculant metering pump  261  and a mixer  262 , which mixes the flocculant with cleaned water. In an example embodiment, the clarifying system is a flocculant application system made by Kemira Oyj of Helsinki, Finland. Other types of clarifying systems could be used as well. 
         [0026]    The water and flocculant is then passed to one or more mixer tanks  264   a - b , which can include, in some embodiments, a slow mixer tank and a fast mixer tank. The mixer tanks are then routed to holding (or clarification) tanks  266   a - b , which hold the mixed sediment filled water and flocculant, until separation of sediments and water can occur. The sediments are then passed to the buffer tanks  252   a - b , while the clarified water is passed via pump  268  to a pre-filtration tank  270 . In the embodiment shown, each of the buffer tanks are sized to hold at least about 350 gallons, while the mixer tanks hold at least about 250 gallons. The holding tanks  266   a - b  are substantially larger, at about 1625 gallons each, which is an adequate amount of water to allow for settling to occur. 
         [0027]    From the buffer tanks  252   a - b , a waste pump  272 , for example an air diaphragm pump powered by an air compressor  274 , routes the waste to a filter press  276 , which presses water out of settled solids, routing the solids to a solid waste collection  278 . In the embodiment shown, the filter press compresses the waste, thereby extracting remaining water and outputting almost dry, solid bricks of sediment. 
         [0028]    From the filter press  276 , water is passed to balance tanks,  280   a - b , which filter the extracted water, which is in turn pumped via pump  281  to the pre-filtration tank  270 . In the embodiment shown, the balance tanks  280   a - b  are configured to hold and filter up to  1600  gallons of water; however, other capacities could be used as well. A pump  271  routes the clarified and/or filtered water to a disk filter system  282 . The disk filter system  282  separates water from waste water, routing the waste water back to the buffer tanks  252   a - b , and providing the water to the heavy metals separating subsystem  210  of  FIG. 2A . In an example embodiment, the disk filter system  282  is a filter made by Arkal Filtration Systems of Jordan Valley, Israel. Other embodiments could use other types of filter systems as well. 
         [0029]    In the embodiment shown, a backflush tank  284  and backflush pump  285  can be used to clean the disk filter system  282  when it becomes clogged. In the example embodiment shown, the backflush tank  284  is sized to hold about 150 gallons, although in other embodiments other sizes of tanks could be used. Additionally, one or more balance pumps, such as pump  283 , can be included in the system to balance the throughput of the system. 
         [0030]    It is noted that, although particular components are discussed above in connection with  FIGS. 2A-2B , other components or configurations of a heavy metals separating subsystem  210  and a water reclamation subsystem  250  could be used. As such, the arrangement illustrated herein is intended as exemplary, rather than limiting. 
         [0031]    Referring now to  FIG. 3 , an example transformation  300  of raw materials and water in a portable mining apparatus according to the present disclosure is shown. The transformation  300  can occur, for example based on use of a portable mining apparatus, such as apparatus  100 ,  200  of FIGS.  1  and  2 A- 2 B. 
         [0032]    In the embodiment shown, raw materials  302  and water are provided to a portable mining apparatus, and large material  308  is separated from slurry source materials  306  which are raw materials below a predetermined size. This separation can occur using any of a variety of types of separating screens, trommels, or other categorization mechanisms. The water and slurry source materials are added to a slurry  310 , which is then processed via hydrocyclones and/or gravimetric separators or other equipment such that heavy metals  314  are separated  312 . The tailings are reintroduced into a slurry  316 . 
         [0033]    The heavy metals  314  are inspected and separated into precious metals  318  (e.g., gold, silver, or other heavy metals of value) and solid waste  320 . This can occur, for example, via use of a sorting table or similar arrangement. Similarly, the slurry can be separated into solid waste  320  and waste water  322 . The waste water can segmented, for example using additional sorting screens, into further solid waste  320  and waste water. The waste water is then passed to a water reclamation subsystem, which applies clarifying agents and filters to reclaim useable water. 
         [0034]    Referring now to  FIG. 4 , a flowchart illustrating a method  400  of mining for heavy metals is shown, according to an example embodiment. The method  400  generally corresponds to the steps performed to transform the materials as illustrated in  FIG. 3 , and can be performed, for example, using any of the apparatus described above in  FIGS. 1-2 , or analogous systems. The method  400  can be performed at least in part by a user of such apparatus, or by control systems incorporated with such apparatus. The method  400  includes receiving raw materials at operation  402 , and classifying those materials at operation  404 . The classifying can occur based on any predetermine size, for example using one or more screening processes to remove large scale particles. A slurry is formed at operation  406 , and overflow of the slurry is routed to a holding tank at operation  408 . Heavy metals are then separated from the tailings at operation  410 , for example using a gravimetric separator and/or a sorting table. The tailings are then passed through screens as part of a dewatering operation  412 . 
         [0035]    The water used during operations  402 - 412  is next reclaimed for reuse, for example by routing the tailings through a series of screens and hydrocyclones and then a clarification process. The tailings generally are then separated and solid wastes are extracted. One or more filters can be used to filter the clarified water separated from the solid wastes at operation  418 , and the clarified and filtered water is then re-introduced into the slurry for use in processing of subsequent raw mining materials. 
         [0036]    It is noted that, although the general operational steps are depicted in  FIG. 4 , additional steps could be included in alternative processes, and that alternative equipment could be used to that discussed herein, in a manner consistent with the present disclosure. 
         [0037]    Referring now to  FIG. 5 . a perspective view of an example portable mining apparatus  500  is shown. The portable mining apparatus  500  can, in some embodiments, correspond to the apparatus  200  of  FIGS. 2A-2B , when that apparatus is used in a portable arrangement. 
         [0038]    In the embodiment shown, the portable mining apparatus  500  generally includes a heavy metal extraction subsystem  502  mounted at least in part to a vehicle-transportable surface, such as a flatbed trailer  504  or shipping container. The portable mining apparatus  500  also includes a water reclamation subsystem  506  mounted at least in part to one or more vehicle-transportable surface, such as a flatbed trailers  508   a - b . In example embodiments, one or more components of the heavy metal extraction subsystem  502  and the water reclamation subsystem  506  can be located on the same or different trailers or surfaces. Furthermore, although in the embodiment shown three flatbed trailers are shown, more or fewer could be used, or could be stacked in shipping containers or other transportation methods could be used. 
         [0039]    In the specific example embodiment shown, select aspects of a portable mining apparatus such as are shown in  FIGS. 2A-2B  are included in the portable mining apparatus  500 . In particular, flatbed trailer  508   b  includes a disk filter system  282  as well as balance tanks  280   a - b . Flatbed trailer  508   a  includes the buffer tanks  252   a - b , as well as holding tanks  266   a - b . Mixer tanks  264   a - b  are shown as located to receive water from the heavy metal extraction subsystem  502  on flatbed trailer  504 , which can include component analogous to those illustrated in  FIG. 2A . A raw materials elevator  510  can also be included for ease of delivery of materials to the heavy metal extraction subsystem  502 . 
         [0040]    Referring to the portable mining apparatus  500  generally, it is noted that various other arrangements of the components of  FIGS. 2A-2B , or other components in different embodiments, could be placed in different configurations on one or more portable surfaces to allow for convenient transport of the mining apparatus to a mining site. Furthermore, and referring to  FIGS. 1-5  generally, it is noted that one example benefit of the disclosed methods and systems over conventional mining operations is the ability to effectively extract heavy metals from the earth without harming the surrounding environment with any dangerous chemicals or solvents, and diminishing the surface disturbance and ground water contamination with the elimination or reduction of tailings containment areas or settling ponds. 
         [0041]    The description and illustration of one or more embodiments provided in this application are not intended to limit or restrict the scope of the invention as claimed in any way. The embodiments, examples, and details provided in this application are considered sufficient to convey possession and enable others to make and use the best mode of claimed invention. The claimed invention should not be construed as being limited to any embodiment, example, or detail provided in this application. Regardless of whether shown and described in combination or separately, the various features (both structural and methodological) are intended to be selectively included or omitted to produce an embodiment with a particular set of features. Having been provided with the description and illustration of the present application, one skilled in the art may envision variations, modifications, and alternate embodiments falling within the spirit of the broader aspects of the claimed invention and the general inventive concept embodied in this application that do not depart from the broader scope.