Abstract:
A pulse of over six kilovolts with a duration of 200 nanoseconds causes an explosion that fragments a mineral deposit with metals embedded therein. The fragmentation separates the metals from the mineral. A conditioning electromagnet temporarily magnetizes the metals. A sorting magnet attracts one of the magnetized metals.

Description:
FIELD OF INVENTION 
   This invention is in the field of precious metal recovery and, more particularly, causing an electrically generated explosive fragmentation that separates the metals from waste materials. 
   DESCRIPTION OF THE PRIOR ART 
   Present day extraction of precious metals from ore is done mainly with chemicals, high temperature furnaces or grinding machines. In a chemical extraction process, for example, a cyanide mixture is prepared from sodium cyanide crystals that are dissolved in a small volume of water and boiled with sodium peroxide. The cyanide mixture is usually placed in a tank with water wherein calcium oxide is added to form a solution that is alkaline. The gold ore is placed within the solution. 
   The recovery of the gold is accomplished by circulating the solution through charcoal filters that are then washed with hot alkalies, such as sodium hydroxide, that augment the solution. Zinc is used to reduce the gold from the augmented solution. 
   There is an unused waste product, called black sand, that is made up of different metals encased in silicate. Black sand cannot be refined through either the chemical, high temperature or grinding process. 
   From the description given hereinbefore, a conventional refining of gold ore that involves a use of caustic chemicals, is undesirably time consuming and is expensive. Additionally, there may be an undesired chemical alteration of some of the matter comprising the ore. 
   SUMMARY OF THE INVENTION 
   According to one aspect of the present invention, a mineral deposit has one or more types of metals embedded therein. While the deposit is under water, an electric pulse of over six kilovolts and a duration in a range of 200 nanoseconds to 500 nanoseconds is used to cause an explosive fragmentation of the deposit that separates the metals from minerals. 
   According to another aspect of the present invention, the fragmented deposit is placed within a magnetic field that causes a temporary magnetization of metals therein. During the magnetization, an attraction between one of the recovered metals and a collection electromagnet is used to separate the one recovered metal from other recovered metals. 
   When the invention is used to recover metals from black sand, for example, approximately two tons of the black sand per hour can be processed. 
   Other objects, features, and advantages of the invention should be apparent from the following description of the preferred embodiment thereof as illustrated in the accompanying drawing. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
       FIG. 1  is a plan view, with a portion broken away, of a tank prior to rock with that is embedded with precious metal being dumped therein; 
       FIG. 2  is a plan view of the tank of  FIG. 1  after the rock embedded with precious metal has been dumped therein. 
       FIG. 3  is a plan view of the tank of  FIG. 1  where an explosion has formed a mixture of fragmented rocks and metal that is loaded onto a drying and dust removal conveyor; 
       FIG. 4  is a perspective view of the mixture of  FIG. 3  being conveyed from the drying and dust removal conveyor to a sorting conveyer; and 
       FIG. 5  is a waveform of excitation applied to an electromagnet of the separation conveyor of  FIG. 4  and a waveform of excitation applied to a conditioning electromagnet. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   A first object of a recovery process described herein is to separate metals from rock wherein the metals are embedded. As shown in  FIG. 1 , a conveyor  10  carries silicon rocks  12  with the metals embedded therein. The conveyor  10  is proximal to a water filled tank  14  at an entrance port  16  thereof. The conveyer  10  is operable to transport rocks from a storage location to the port  16 . 
   An upper portion of the tank  14  includes a chute  18 . Although the chute  18  is generally horizontal, it has an end slopes downward to provide an exit port  22  from the tank  14 . 
   Within the tank  14  is a crib  24  of wire mesh construction. The crib  24  has an open top  26 . Additionally, tracks  28  extend from a location near a bottom  30  of the tank  14 , through the entrance port  20  to the exit port  22 . The crib  24  is moveable along the tracks  28 . 
   As shown in  FIG. 2 . the rocks  12  are dumped from the conveyor  10  through the top  26  into the crib  24 . Thereafter, a generator  30  generates a pulse of over six kilovolts with a duration of approximately 200 nanoseconds. The pulse is transmitted through the water in the tank  14  to the rocks  12  thereby causing the rocks  12  to explode and form a mixture of fragmented rocks and metals  13 . 
   The interior of the tank  14 , the crib  24  and the tracks  28  are coated with a plastic that has a high electrical resistance to prevent a transmission therethrough of the pulse. 
   The pulse may cause an accumulation of unwanted debris in the tank. The debris is eliminated by operation of a filtration system that includes a filter  32  that has an inlet  34  connected to the interior of the tank  14  through a pipe  36 . Hence, water from the tank  14  passes into the filter  32 . 
   An outlet port  38  of the filter  32  is connected through a pipe  40  to a pump  42  at an inlet  44  thereof. An outlet  46  of the pump  42  is connected through a pipe  48  to the tank  14 . In other words, water taken from the tank  14  is filtered and pumped back the tank  14 . 
   A second object of the recovery process is to separate different metals of the fragmented mixture  13  from each other and from non-metallic debris. As shown in  FIG. 3 , the crib  24  is moved along the tracks  28  to the port  22  where the fragmented mixture  13  is deposited upon a drying and dust removal conveyor belt  50 . 
   As shown in  FIG. 4 , the belt  50  conveys the fragmented mixture  13  onto a sorting belt  52 . A plurality of fans  54  are proximal to a path of conveyance of the belt  50 . The fans  54  blow warm air from a heater  55  thereby blowing away unwanted dust and debris and drying the fragmented mixture  13 . 
   The belt  52  has a carrying part  56  and a return part  58 . The mixture  13  is carried on the carrying part  56 . A conditioning electromagnet  60  is positioned between the parts  56 ,  58 . Excitation wires of the conditioning electromagnet  60  are not shown. A separation conveyor belt  62  is positioned in a plane that is parallel to the planes of the parts  56 ,  58 . 
   The belt  62  has a carrying part  64  and a return part  66  that are driven by wheels  68 ,  70 . The parts  64 ,  66  are driven along paths that are perpendicular to the paths of the parts  56 ,  58 . An collection electromagnet  72  is positioned within the wheel  68 . Excitation wires of the collection electromagnet  72  are not shown. 
   As shown in  FIG. 5 , a voltage, V A , that is applied to the excitation wires of the collection electromagnet  72  is comprised of pulses of ½ second duration with ½ second therebetween. A voltage, V B , that is applied to the excitation wires of the conditioning electromagnet  60 , shown on the same time scale as the voltage, V A , is comprised of pulses similar to those of the voltage, V A . However, when the voltage, V A , has its zero value, the voltage, V B , has its non-zero value and vice versa. 
   It should be understood that all metals are magnetized when placed in a magnetic field. When the field is removed, a metal such as gold, for example, retains its magnetism for a time on the order of one second. Additionally, the strength of the magnetism retained by each metal is different. As explained hereinafter, this difference makes possible a reliable apparatus and process for separating metals of the fragmented mixture  13  from each other. 
   After metals of the fragmented mixture  13  have been magnetized by the conditioning magnet  60 , they are attracted to the belt  62  by the collection magnet  72 . However, the strength of the attraction of the collection magnet  72  is inversely related to a vertical distance, D 1 , between the belt  62  and the fragmented mixture  13 . 
   Iron acquires a first level of magnetization from the conditioning electromagnet  60 . The distance, D 1 , is selected to cause magnetism provided by the collection magnet  72  to be sufficient to move iron to the belt  62  but insufficient to move metals that acquire less than the first level of magnetization. Aluminum, gold, silver and platinum are examples of metals that acquire less than the first level of magnetization. 
   In other words, only iron is attracted to the belt  62 . Beneath an end  74  of the belt  62  is a collection tray  76 . Iron from the belt  62  falls into the tray  76 . 
   Aluminum acquires a second level of magnetization from the conditioning electromagnet  60 . Adjacent to the belt  62  is a conveyor belt  78  that is similar to the belt  62 . There is a vertical distance, D 2 , between the belt  78  and the part  56 . 
   The belt  78  has a collection electromagnet  79  that is similar to the collection electromagnet  72 . The distance, D 2 , is less that the distance, D 1 . The distance, D 2 , is selected to cause magnetism provided by the collection electromagnet  79  to be sufficient to move aluminum to the belt  78  but insufficient to move metals that acquire less than the second level of magnetization. Gold, silver and platinum are examples of metals that acquire less than the second level of magnetization. 
   In other words, only aluminum is attracted to the belt  78 . Beneath an end  80  of the belt  78  is a collection tray  82 . Aluminum from the belt  78  falls into the tray  82 . 
   Gold acquires a third level of magnetization from the conditioning electromagnet  60 . Adjacent to the belt  78  is a conveyor belt  84  that is similar to the belt  62 . There is a vertical distance, D 3 , between the belt  84  and the part  56 . 
   The belt  84  has a collection electromagnet  85  that is similar to the collection electromagnet  72 . The distance, D 3 , is less that the distance, D 2 . The distance, D 3 , is selected to cause magnetism provided by the collection electromagnet  85  to be sufficient to move gold to the belt  84  but insufficient to move metals that acquire less than third level of magnetization. Silver and platinum are examples of metals that acquire less than the third level of magnetization. 
   In other words, only gold is attracted to the belt  84 . Beneath an end  86  of the belt  84  is a collection tray  88 . Gold from the belt  84  falls into the tray  88 . 
   Silver acquires a fourth level of magnetization from the conditioning electromagnet  60 . Adjacent to the belt  84  is a conveyor belt  90  that is similar to the belt  62 . There is a vertical distance, D 4 , between the belt  84  and the part  56 . 
   The belt  90  has a collection electromagnet  91  that is similar to the conditioning electromagnet  72 . The distance, D 4 , is less that the distance, D 3 . The distance, D 4 , is selected to cause magnetism provided by the collection electromagnet  91  to be sufficient to move silver to the belt  84  but insufficient to move metals that acquire less than the fourth level of magnetization. Platinum is an example of a metal that acquires less than the fourth level of magnetization. 
   In other words, only silver is attracted to the belt  90 . Beneath an end  92  of the belt  90  is a collection tray  94 . Silver from the belt  90  falls into the tray  94 . 
   Platinum acquires a fifth level of magnetization from the conditioning electromagnet  60 . Adjacent to the belt  90  is a conveyor belt  96  that is similar to the belt  62 . There is a vertical distance, D 5 , between the belt  96  and the part  56 . 
   The belt  96  has a collection electromagnet  97  similar to the collection electromagnet  72 . The distance, D 5 , is less that the distance, D 4 . The distance, D 5 , is selected to cause magnetism provided by the collection electromagnet  97  to be sufficient to move platinum to the belt  96  but insufficient to move metals that acquire less than the fifth level of magnetization. 
   In other words, only platinum is attracted to the belt  96 . Beneath an end  98  of the belt  96  is a collection tray  100 . Platinum from the belt  96  falls into the tray  100 . 
   Non-metallic debris falls from the part  56  into a tray  102 .