Patent Publication Number: US-2002003323-A1

Title: Volatilizing and recovery of precious metals using air/gas injection

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
     [0001] This application is entitled to the benefit of a Patent Pending Application (PPA) serial No. 60/207,429, filed May, 30, 2000. 
    
    
     
       BACKGROUND  
       [0002] 1. Field of the Invention  
       [0003] This invention relates to precious metal extraction, specifically to the volatilizing and recovery of precious, and other minerals using air/gas injection, from aqueous solution(s), slurries, including different type(s) of mineral ore bodies.  
       [0004] 2. Description of Prior Art  
       [0005] Early inventors weren&#39;t aware of volatile metals existing in any quantities, therefore this area of mineral separation was overlooked. This invention covers an area that hasn&#39;t been covered, and the invention deals with the volatile aspect of the minerals separation and recovery process in a non-polluting environmentally clean procedure.  
       [0006] We can find no prior art that covers the essence of this invention, we have submitted these examples of inventors dealing with non volatile precious metals. Inventors over the years have come up with many process, including the three ore dressing applications that have been submitted. U.S. Pat. No. 4,814,003, a coherent radiation process by Bergner. U.S. Pat. No. 4,436,617 a froth floatation process by Moore and, Tassoni and U.S. Pat. No. 3,701,421 by Maxwell also froth floatation. The latter two using froth floatation have a limited degree of success on concentrating pacific non-volatile minerals. However floatation is a very environmentally unsound practice. As the above floatation process using air injected into the ore pulp or slurry, and dispersed by agitation. This was used to accomplish froth mineral separation. With the addition of oils and acids and other chemicals to complex ore gangue minerals. That caused minerals to float to the surface to be skimmed off in the froth. It left behind ore gangue contaminated with chemicals, oils and acids, causing long term environmental disposal problems. The floatation patent U.S. Pat. No. 3,701,421 is a floatation process using low volume air, being disbursed by agitation in the slurry to collect ore minerals by froth floatation. And U.S. Pat. No. 4,436,617, gasification process address&#39;s injecting the slurry with gasses to recover coal, neither of these floatation patents could address the volatility and recovery of volatile precious metals. They could not be used to extract volatile precious metals even if the process&#39;s were combined. U.S. Pat. No. 4,814,003; uses a laser beam to volatilize precious metals from feed material using extreme heat The metals are either melted or volatilized, the metals are then collected and filtered off to be processed. Although laser beam technology can be utilized to volatilize and recover low valance precious metals, it is slow and expensive to operate. The cost is prohibitive as ore bodies get lower, and lower grade, and the cost of mining goes up and up. The mining operators have to run large tonnage to be cost effective. This process could not deal with high valance unstable precious metals liberated by the heat and could not be stabilized as a metallic salt using this process.  
       SUMMARY OF THE INVENTION  
       [0007] In accordance with the present invention, volatilizing and recovery of precious metals and other minerals using air/gas injection.  
       [0008] Objects and Advantages  
       [0009] Accordingly several objects and advantages of the invention are:  
       [0010] (A) To provide a easy, cheap volatile mineral extraction and a recovery process to the minerals industry.  
       [0011] (B) Using air or other gases to liberate volatile precious metals and other minerals.  
       [0012] (C) Provide a process to strip volatile precious metals and other minerals from aqueous solution(s), slurries, including ores in a matter of seconds.  
       [0013] (D) To capture the volatile precious metals in a air/gas stream and stabilize them as a stable metal ion in a aqueous solution.  
       [0014] (E) To provide extraction of volatile precious metals and other minerals from ores of predetermined size and moisture content using air injection.  
       [0015] (F) Provide a process that can extract precious metals without contaminating the ore, water sources, or other aqueous solution(s) or the processing site, recovering minerals in an environmentally sound and responsible manner.  
       [0016] (G) To provide a process that may use either, hot, cold or prevailing ambient air temperatures as a catalyst in the volatilizing and stripping of water(s) or ores of their precious metals and other minerals.  
       [0017] (H) Further objects and advantages are to provide small business an opportunity to operate their own company, from a small start-up cost.  
       [0018] (I) Further objects and advantages are that it opens up thousands of potential ore bodies, water sources, industrial wastes, sewage and numerous other possibilities that could potentially have precious metals or other valuable minerals that at the present time are being volatilized and not recovered.  
       [0019] (J) Another further object and advantage is that marginal ores, where minerals are recovered by a conventional recovery process, may turn into a higher grade of ore by utilizing the present invention to recover the volatile minerals from the process water. 
     
    
    
     DRAWING FIGURES  
     [0020] In the drawings FIG. 1, shows the cut away version of the aqueous or chemical solution and slurry process. It captures the essence of the invention.  
     [0021]FIG. 2, is relating to a different processes, that of processing precious metal bearing feed material.  
     REFERENCE NUMERALS IN DRAWINGS  
     [0022]FIG. 1 Cut Away  
     [0023] 206 —Feed Pump  
     [0024] 208 —Feed Line Discharge  
     [0025] 210 —Impeller Shaft  
     [0026] 212 —In-side of The Tank Wall  
     [0027] 214 —Feed Line  
     [0028] 216 —Line Valve  
     [0029] 219 —Top of Tank  
     [0030] 221 —Electric Motor  
     [0031] 223 —Air Line  
     [0032] 224 —Air Compressor  
     [0033] 225 —Void  
     [0034] 226 —Plumbing  
     [0035] 227 —P-Trap  
     [0036] 228 —Outlet  
     [0037] 229 —Aqueous or Chemical Solutions or Slurry  
     [0038] 232 —Impeller, Mechanical or Natural  
     [0039] 233 —Agitation Tank  
     [0040] 234 —Make-Up Tank Pump  
     [0041] 237 —Precipitate Valve  
     [0042] 240 —Precious Metal Precipitate  
     [0043] 244 —Make-up Tank  
     [0044] 246 —Make-up Tank Solution  
     [0045] 248 —Reservoir Solution  
     [0046] 250 —Precipitation Tank  
     [0047] 251 —Over Flow  
     [0048] 255 —Plumbing Apparatus  
     [0049] 256 —Gas Scrubbing Tower  
     [0050] 258 —Precious Metal Laden Air/Gases  
     [0051] 260 —Solution Spray  
     [0052] 262 —Spray Nozzle  
     [0053] 263 —Vent Hole  
     [0054]FIG. 2 
     [0055] 302 —Feed Material  
     [0056] 304 —Feeder Bunker  
     [0057] 305 —Inlet Auger  
     [0058] 306 —Feed Chute  
     [0059] 307 —Processing Tank or Container  
     [0060] 310 —Pre-sized Feed Material  
     [0061] 311 —Compressor  
     [0062] 312 —Heater or Refrigerated  
     [0063] 314 —Air Line  
     [0064] 316 —Air Currents  
     [0065] 318 —Outlet Auger  
     [0066] 320 —Stripped Feed Material  
     [0067] 255 —Plumbing Apparatus  
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0068] A preferred embodiment of the air injection process of the present invention is illustrated in FIG. 1  
     [0069] Referring now to FIG. 1, a feed pump  206  on inlet side of agitation tank  233 , pumps a aqueous or chemical solution or slurry  229  through feed line  214  to agitation tank  233 . The aqueous or chemical solutions or slurry  229 , rate of flow is controlled by line valve  216 . The feed line discharge  208 , discharges within a few inches of the bottom of the agitation tank  233 , near the inside of the tank wall  212 . The agitation tank electric motor  221  is connected to the impeller shaft  210 . The impeller shaft  210  drives the impeller  232  at the bottom of the agitation tank  233 . The air compressor  224  supplies air to the system. The compressor air line  223  brings the air to the impeller  232 . The impeller or by natural or mechanical means disburses, drives, and breaks down the air in the form of tiny bubbles throughout the agitation tank  233 . These small bubbles act as a catalyst, liberating volatile minerals, causing said air/gases to become laden with volatile minerals. The aqueous or chemical solution or slurry  229  exits at the outlet  228  on the opposite side of the agitation tank  233  from the inlet  214 . The exit solutions are P-trapped  227  at the outlet  228  causing a vapor barrier so as not to loose any of the precious metal laden gasses  258 . The precious metal laden gasses  258  are trapped in a void  225  at the top of the tank  219 . The void  225  is between the top of the aqueous or chemical solution or slurry  229  and the top of the tank  219 . These precious metal laden gases  258  are sent through the plumbing apparatus  226  to the gas scrubbing tower  256 . All gasses entering the gas scrubbing tower  256  are scrubbed by combination of sodium chemical solutions and, or other chemicals, such as, but not limited too sodium sulfite or sodium thiosulphate. From a make-up tank pump  234 , pumping sodium solutions, but not limited to, the above mentioned other chemicals. It is conveyed through plumbing  255 , up to the gas scrubbing tower  256 . The spray nozzle  262  directs a solution spray  260  mist downward, scrubbing the upward flow of precious metal laden gasses  258 . Where the volatile precious metals and other minerals are now separated from the air/gases. The air/gases now stripped of minerals, travels out the top of the tower, through a vent hole  263  in the top of the scrubbing tower  256 . The spray picks up gaseous volatile metal and other minerals along the way, carrying them into the reservoir solution  248  and are either converted to a stable metal ion or are precipitated out and settle to the bottom of the precipitation tank  250 . Where, if the precipitation process is used, utilizing sodium sulfite, or other suitable chemicals, it will settle out as a precious metal precipitate  240 . At the bottom of the precipitation tank  250  is the precipitate valve  237 . Minerals and precious metal precipitate  240  can be drawn off or the reservoir solution  248  can be changed as needed. The reservoir solution  248  is returned through the return overflow line  251  back to the solution make-up tank  244 . Where the make up tank solution starts the process all over again. Sodium thiosulphate may be used instead of sodium sulfite. Instead of precipitating the precious metals with sodium sulfite, you may elect to electrowin the precious metals by using thiosulphate in conjunction with sodium hydroxide.  
     [0070]FIG. 2, Additional Embodiments  
     [0071] Certain volatile feed material minerals are susceptible to the air injection process. Referring now to FIG. 2. Certain feed materials(s)  302  of a predetermined size and moisture content are loaded into a feeder bunker  304 , where it is fed by a inlet auger  305  into the feed chute  306 . The feed material  302  falls into the processing tank or container  307 . The pre-sized feed material  310  lays in the angle of repose, while the outlet auger  318  slowly discharges the stripped feed material  320  off the bottom of the tank and out the end of the outlet auger  318 . Air is fed by compressor  311  along the bottom of the processing tank or container  307  by a air line  314  and is fed along the tank bottom and injected into the pre-sized feed material  310 , is exposed to circulating air/gases. Said air/gas currents  316  perk upward through the pre sized feed material  310 , wherein said feed material is stripped of volatile minerals. These minerals are drawn off as in FIG. 1, through the plumbing apparatus  226 , where it goes to the gas scrubbing tower  256 , where the minerals are processed as in the previous process in FIG. 1.  
     [0072]FIG. 2 Alternative Embodiments  
     [0073] There are also additional possibilities with regard to heating or cooling the air with a heater or refrigeration  312  or by other means. The heated air/gases increases the volatility of aqueous or chemical solutions, slurry or feed material. The heated air may increase the volume or the gallons per minute or tons per hour of aqueous or chemical, slurry or feed material being run. It also could increase the size of the feed material being stripped of volatile minerals. The volatility of minerals can be controlled by chilling or cooling the air being injected into aqueous or chemical solutions or slurry and feed material. Making selective mineral separation possible. The shortening the retention time of the feed material using warmer temperatures of air, also could lead to a coarser sizing of the feed material fed into the processing tank or container. Also the volatilizing other minerals that wouldn&#39;t be volatilized at ambient temperatures. Also cooling the air temperatures could lead to selective volatilization of volatile minerals.  
     [0074]FIG. 1 Other Additional Embodiments  
     [0075] Referring to FIG. 1 feed materials that have a finer grained texture, that&#39;s not suitable for the above process. This type of feed material may be processed using this method. Feed materials crushed and ground to a fine consistency in water forming a slurry and thinned with water to a gravy consistency. This aqueous solution or slurry may be then fed into the FIG. 1 apparatus. The air/gas injection process effectively strips the volatile precious metals and other minerals from the finely ground feed material.  
     [0076] Other Alternative Embodiments  
     [0077] The volatilizing and recovery of precious metals using air injection may also be used near the end of a conventional metal recovery or industrial or municipal processing plants running their waste solutions through the air/gas injection process before it goes to the settling, or containment ponds stripping the volatile precious metals and other minerals caught in the waste water. Or it could be used in the tailing pond, pumping the waste water through the air/gas injection process after letting the solids sink to the bottom of the settling pond and recovering said volatile precious metals and other minerals.  
     [0078] Further Additional Embodiments  
     [0079] The preheating of aqueous or chemical, slurry or feed material prior to air injection will selectively volatilize unwanted minerals before the air injection process. Slowing the process of saturating the stripping solution of unwanted minerals.  
     [0080] Advantages  
     [0081] From the description above, a number of advantages of my air/gas injection process becomes evident.  
     [0082] (A) Providing a low cost extraction process to the minerals industry.  
     [0083] (B) Providing a clean, environmentally sound process to extract minerals.  
     [0084] (C) Provide a process for municipalities to use the air injection process on municipal water intakes and sewage and storm water to extract minerals and metals. The extraction process could offset the cost of providing water and sewer to the municipality.  
     [0085] (D) It would also provide an opportunity for conventional mineral extraction operations to use the injection process on their waste water to increase their profitability.  
     [0086] (E) Provide small business entrepreneur with a low cost set up and operation.  
     [0087] (F) Open up thousands of ore bodies and waters sources to be utilized to produce precious metals or other minerals.  
     [0088] Operation—FIG. 1, 2  
     [0089] The manor of using this process, is to aerate the water sources, or other aqueous or chemical solution(s), slurries, including feed material(s). The inter action between air/gases and volatile minerals in a aqueous solutions  229 , or feed materials is unique. The air/gases injected into volatile minerals contained in these sources, acts as a catalyst and causes said volatile precious metals and minerals to volatilize. These air/gases percolating up through the aqueous solutions  229  and pre-sized feed materials  310 , pick up these volatile minerals and carry them to the surface of the aqueous solutions  229  or pre-sized feed materials  310 . The minerals trapped in the gases are transported to the gas scrubbing tower  256 , where the precious metal laden gases  258  are sprayed with a mild chemical solution spray  260  of sodium chemical solutions or other suitable chemicals. The feed material type, porosity and moisture content go into the type of volatile feed material extraction process to be used. The more porose of these feed materials may be processed as shown in FIG. 4. Now referring to FIG. 2, the feed material is pre sized and loaded into a Feeder Bunker  304 . It is feed through the inlet auger  305  into a feed chute  306  and falls into the processing tank or container  307 . There, air or other gases are fed from a compressor  311 , into the heater  312 , where the air/gas may be sent into the bottom of the ore processing tank or container  307 , at either ambient, heated or cool temperatures. The air/gas works its way up or through the feed material in the processing tank or container  307  where it is trapped at the top. The gas is drawn off through a plumbing apparatus  226  at the top of the tank to the gas scrubbing tower  256 . These gases are stripped of the volatile minerals as above in the aqueous solution process. Feed materials with a harder and tighter matrix may be processed as in FIG. 1. By pre-grinding the feed material with water to trap the volatile minerals in a aqueous solution. This aqueous solution or slurry is thinned out to a thin gravy consistency using water. This slurry may then be fed into the agitation tank  233  and agitated with air or other gases. The multitude of small bubbles strip the aqueous slurry of volatile minerals and carries the volatile minerals to the top of the agitation tank  233 . The air/gases are drawn off into the scrubber tower, where they are stripped of their volatile minerals. The volatile minerals are stabilized or precipitated in the solutions in the precipitation tank.  
     [0090] The main embodiment of the present invention, shown in FIG. 1 has several advantages. For example, heavy metals are stripped from aqueous solutions and ores in a environmentally clean manor. Leaving the aqueous solutions and ores cleaner, devoid of volatile minerals. It also opens up possibilities of cleaning up volatile heavy metals out of sewage, runoff or irrigation waters, municipal water supplies or possibly from super fund sites, or from other similar applications.  
     [0091] The effectiveness of the present technique for the extraction and recovery of precious metals and other volatile minerals, is further enhanced by the short retention time of the aqueous solutions, slurries and feed materials to the air/gas injection process. Letting the operator run larger volumes of aqueous solution, slurries or feed materials through the process in a short time. The process is further enhanced by the cost of setting up the processing plant and processing the aqueous solutions or feed materials at a fraction of the cost of conventional processing.  
     CONCLUSION, RAMIFICATIONS, AND SCOPE OF INVENTION  
     [0092] Thus the reader will see that air/gas injection as pertaining to recovery of volatile precious metals is a major mile stone in the mining industry&#39;s recovery of precious metals. The environmental ramifications of this invention will be an asset to the industry and the country. Not only is it a environmentally clean process, it is cheap and cost effective in the recovery of precious metals. Furthermore, the air injection process has the additional advantages in that:  
     [0093] The invention not only works for water but also works for waste, run off, or sewage water, and dry or wet feed materials as well.  
     [0094] While I believe, but will not be bound by, that even conventional ore bodies contain appreciable amounts of volatile metals. These metals are now being, and have been lost in the processing of these ores by conventional means, that can now be recovered.  
     [0095] It also may be utilized by municipalities to be used as stripping process in industrial applications. Many sewage lagoons or other containment ponds may find the above application a viable part of their process, offsetting their cost of running their operation by recovering precious metals.  
     [0096] This invention will open the door to many small miners, showing them the way to mine and recover minerals in an environmentally sound manner.  
     [0097] Accordingly, the scope of the invention should be determined not by the embodiment(s) illustrated, but by the appended claims and their legal equivalents.  
     [0098] While my above description contains many specifications, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible. For example the above process may be:  
     [0099] Changed in size.  
     [0100] Made of different material.  
     [0101] Connected or associated with its adjacent elements in a different manner.  
     [0102] Given a different mode or function of operation.  
     [0103] Made integrally or separately.  
     [0104] Use different combination of chemicals.  
     [0105] Not limited to just one type of scrubber or washer.  
     [0106] Not limited to just one type of air injection or disbursing.  
     [0107] Nor limited to just one type of precious metal precipitation or recovery system.  
     [0108] Nor limited to air as the only gas.  
     [0109] Nor limited to the temperature of air or gasses.  
     U.S. PATENT DOCUMENTS  
     References Cited  
     [0110] U.S. Pat. No. 4,814,003 Mar. 21, 1989 Richard M. Bergner  
     [0111] U.S. Pat. No. 4,436,617 Mar. 13, 1984 Wiley I. Moore, Ronald I. Tassoni  
     [0112] U.S. Pat. No. 3,701,421 Oct. 31, 1972 John Russell Maxwell