Abstract:
The methods and apparatus separate fines from crushed rock and stone. A motorized conveyor belt system is activated that includes a conveyor belt moving in an upward direction. A spray system is activated to spray a fluid on an underneath surface of the conveyor belt. The mixture of rock and fines are directed to the conveyor belt. The rock tumbles or rolls down the conveyor belt and is collected at a first end of the conveyor belt. The fines stick or adhere to the conveyor belt, and the fines are scraped off of the conveyor belt at or near the second end of the conveyor belt. 
     The apparatus includes a conveyor belt system, including a moving belt, a motor to move the belt, the belt including a first end and a second end, wherein the second end is elevated relative to the first end. The apparatus includes a spray system, including a source of fluid, a sprayer in fluidic communication with the source of the fluid, and the sprayer positioned to spray a surface of the belt with the fluid. The apparatus includes a material feed system, including a hopper to discharge a material of fines and rock onto the belt proximate the second end of the belt, and the belt moving from the first end to the second end in an upward direction. The apparatus includes a fines discharge to receive fines from the belt and a rock discharge at the first end of the belt.

Description:
FIELD OF INVENTION 
     The present invention relates to methods and apparatus for separating fines and smaller particles from a rock mixture. 
     BACKGROUND OF INVENTION 
     Crushed rock is typically used for many construction applications. Crushed rock is often used as a lower layer for the construction of roads, pavement, and highways. The crushed rock may be spread over the ground, and asphalt or concrete may be applied over the top of the layer of crushed rock. 
     The crushed rock is often mined from rock quarries. Large rock is crushed and broken into smaller rock particles. During the processing of the larger rock into the crushed rock, dust, fines, and small particulate matter is inherently produced. Many road construction projects require that the crushed rock only contain a minimum level of this “fine” material. Crushed rock that contains too much of this fine material may be rejected as being out of specification. Typically, many road construction projects require that the crushed rock have a content of no more than approximately 5% fine material. The excess fine content in the crushed rock results in an increased amount of oil needed in the asphalt. If the crushed rock contains an excess amount of the fines, then the entire shipment of the crushed rock may be rejected. 
     Previous attempts to remove fines or lower the fine content of crushed rock have involved expensive and difficult to maintain equipment. Moreover, many of the prior art attempts and designs to remove the fines from the crushed rock results in excessive waste by-products. For example, one such prior art device to remove fines from the crushed rock includes an air separation device. The air separation device uses large fans and turbines to blow the fines from the crushed rock. The fines are collected in receptacles that allow the blown air to pass through. However, the blowing of the fines degradates the fans and turbines of such air separation devices. Constant maintenance and replacements of such fans and turbines is required. 
     Other attempts to remove the fines from the crushed rock involve the use of log washers. The crushed rock and fines are washed in the log washers with water in order to separate the fines from the crushed rock. The fines typically float, and the fine and are washed from the heavier crushed rock particles. However, the use of the log washers results in waste pools of water containing the fines. Also, the now wet fines removed by the log washer may require additional drying steps or processes before the fines can be used as a material for certain applications. 
     Also, conventional wet or dry vibrating screens with very fine openings are employed to remove the fines from the crushed rock. Unfortunately, the screens used in the dry screening process have very fine openings, which tend to plug with rock material. Force-drying the fines and crushed rock, prior to the dry screening, alleviates some of problems with the plugging of the openings of the screen, but this step requires additional equipment and labor. Wet screening results in some of the similar discharge water problems as encountered with log washing. As such, the wet and dry screening processes are problematic for various reasons. 
     SUMMARY OF THE INVENTION 
     The apparatus and methods described herein provide for fine and dust control and for fine and dust removal from rocks, stones, or other debris obtained from a quarry, wherein such rock, stone, other debris containing fines, dust, or particulate matter would be undesirable in a particular application. The methods and apparatus provide an efficient and effective manner to remove fines and dust from the rock and stones. The methods and apparatus provide less environmental problems as compared to prior art devices and processes. 
     The methods and apparatus remove fines from the crushed rock and stone by combining an elevated conveyor belt system, a spray system, a material feed hopper, a scraper, and a dust removal discharge chute. A motor operates a conveyor belt, which is angled at a substantial degree relative to the ground, so that the crushed rock material is not conveyed up and over the top of the conveyor belt. The conveyor belt moves in one direction (toward the top of the elevated conveyor) with the fines, while the crushed rock material moves down the conveyor belt in the direction opposite of the travel of the conveyor belt. 
     In operation, the crushed rock material is fed onto the conveyor belt from the material feed hopper or other material loading means. The conveyor belt and the coarse particles of the crushed rock material move in opposite directions, thereby creating a counter-flow between the conveyor belt and the coarse particles of the crushed rock material. The fines of the crushed rock material move with and are retained on the conveyor belt. The fines remain on the conveyor belt until removed by scraping or other removal means and methods. 
     The conveyor belt is sprayed with water or other wetting agents. The conveyor belt may be vibrated by cage idlers or other devices. The vibration aids in rolling and bouncing the coarse particles of the crushed rock material down the conveyor belt and providing many opportunities for the dust and fines, on and among the coarse particles, to contact the conveyor belt. The vibration of the conveyor belt tends to discharge the coarse particles from the conveyor belt surface leaving more “open space” on the conveyor belt to collect the fines. More or less vibration influences the gradation of the finished product, and, in some cases, less vibration may be desirable to achieve a certain specification of crushed rock particles. The dust and fines from the crushed rock material are attracted by the water or other wetting agents on the conveyor belt and collect on the conveyor belt. The fines mixed in with the crushed rock, or that are sticking to the crushed rock, are generally separated and collected on the conveyor belt. 
     A scraper located toward the top and at the underside of the conveyor belt scrapes away the collected fines and dust, which may be directed to the discharge chute and then collected for disposal or sale at the end of the discharge chute. The material being conveyed, moving in the opposite direction of the conveyor belt, moves down the conveyor belt by gravity and into a collection apparatus. 
     As described herein, the methods and apparatus remove fines from larger rock. As used herein, the term “fines” includes dust, small particles, and other particulate matter mixed in and/or adhered to larger coarse rock particles, crushed rock and stone. The fines are generally the same material as the larger rock, namely crushed limestone, although the methods and apparatus may be used with other rock and stone materials. The fines are typically the material that passes through a 200 mesh on a standard sieve. The term “200 mesh,” is well known to one of ordinary skill in the art and generally refers to a mesh sheet having approximately 200 openings per square inch. The fines that pass through the 200 mesh may be referred to as a −200 material. Typically, crushed rock particles with an excess amount of −200 content may be out of specification for a certain project. Many construction and road building applications require a −200 content of less than 5% by weight, however the exact level will vary depending on the individual specification. As used herein, the term “coarse particles” are the component of the crushed rock mixture separated from the fines. The coarse particles will generally not pass through the 200 mesh. 
     The methods and apparatus described herein work most efficiently when the mixture of material comprising the crushed rock and fines is in a relatively dry state. Water should not be added to the crushed rock material prior to processing with the methods and apparatus herein described. A wet crushed rock material will reduce the efficiency of the methods and apparatus. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front, perspective view of the apparatus for removing the fines from the mixture of rock and fines. 
         FIG. 2  is a right side view of the apparatus for removing the fines from the mixture of rock and fines. 
         FIG. 3  is a left side view of the apparatus for removing the fines from the mixture of rock and fines. 
         FIG. 4  is a front view of the apparatus for removing the fines from the mixture of rock and fines. 
         FIG. 5  is a rear view of the apparatus for removing the fines from the mixture of rock and fines. 
         FIG. 6  is a top view of the apparatus for removing the fines from the mixture of rock and fines. 
         FIG. 7  is a schematic view of the belt system, the rock discharge and the fines discharge for removing the fines from the mixture of rock and fines. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The methods and apparatus will now be described with respect to the Figures. An apparatus  10  for removing fines from crushed rock material is shown in  FIG. 1 . The apparatus  10  receives a supply of a crushed rock material  50 , which includes a mixture of fines  54 , coarse particles  58 , and other matter. The apparatus  10  separates at least some of the fines  54  from the coarse particles  58 . The apparatus  10  lowers the content of fines  54  in the crushed rock material  50 . 
     The crushed rock material  50  has been mined or collected from a rock quarry or other source. Typically, most of the large bulky rocks in the crushed rock material  50 , over for example, several inches in size, have already been reduced or crushed. 
     The apparatus  10  includes a frame  60  that supports a conveyor belt system  100 . The frame  60  is generally constructed of rigid material, such as steel, with sufficient strength to supports the components of the apparatus  10 . The frame  60  may rest on a trailer, the ground, or be integrally connected to further quarry and rock processing equipment. 
     The conveyor belt system  100  includes a conveyor belt  102  that is moved by a motor  150 . The conveyor belt  102  is positioned in a slanting or sloping manner in which a first end  106  of the conveyor belt  102  is lower than a higher, second end  107  of the conveyor belt  102 . The conveyor belt  102  further includes a top surface  104  and a bottom surface  105 . The material  50  is fed or dropped onto the top surface  104  adjacent or near the second end  107  of the conveyor belt  102 . By dropping the material  50  onto the top surface  104  adjacent or near the second end  107 , the material  50  is allowed to contact much of or a majority of the conveyor belt  102 . The material  50  may be dropped onto the top surface  104  anywhere in the upper third region of the length of the conveyor belt  102  adjacent the second end  107 . By dropping the material in this region of the conveyor bolt  103 , unwanted carryover of the coarse particles  58  with the fines  54  into a discharge chute  250  is reduced. 
     The motor  150  is in operational engagement with the conveyor belt  102 . The motor  150  actuates a head pulley  153  that causes the conveyor belt  102  to move in an upward or elevating direction, i.e., the conveyor belt  102  moves from the lower, first end  106  toward the higher, second end  107 . A tail pulley  156  provides rotating support to the moving conveyor belt  102  at the first end  106 . The conveyor belt  102  provides an endless belt moving between the head pulley  153  and the tail pulley  156 . 
     With reference to  FIGS. 2 and 3 , a plurality of optional cage idlers  159  may be positioned along the conveyor belt  102 . In the embodiment shown in the Figures, the cage idlers  159  are positioned between the head pulley  153  and the tail pulley  156 . The cage idlers  159  provide a vibrating force to the conveyor belt  102 . The vibration assists in causing the coarse particles  58  to discharge from the conveyor belt  102 , i.e., the coarse particles  58  bounce, tumble, and/or roll down the conveyor belt  102  toward the first end  106 . 
     The conveyor belt  102  is mounted onto a conveyor frame  180 . The conveyor frame  180  supports the head pulley  153 , the tail pulley  156 , and the cage idlers  159  in an operational engagement with the conveyor belt  102 . The conveyor belt system  100  further includes a pivoting belt adjusting system  190  and a belt angle adjuster  194  to vary the angle of the conveyor belt  102 . The conveyor belt system  100  further includes a tail-pulley belt tensioner. 
     Most or all of the length of the conveyor belt  102  is provided with a cover  170  to help contain the crushed rock material  50  on or about the conveyor belt  102 . The coarse particles  58  of the crushed rock material  50  may roll down and bounce with such speed and force that the cover  170  is necessary to maintain and collect the coarse particles  58  discharging at the first end  106  instead of the coarse particles  58  bouncing away from the apparatus  10 . 
     A material feed hopper system  400  feeds or directs the crushed rock material  50  to the conveyor belt  102 . In the embodiment shown, the material feed hopper system  400  includes a hopper  405  with an interior holding portion  410 . The interior holding portion  410  may be supplied with the crushed rock material  50  via a conveyor belt, a bucket lifter, chute, vibrating feeder, belt feeder, etc. or other means to provide the hopper  405  with an even or controlled flow of the crushed rock material  50 . The hopper  405  may be replaced with any device that provides an adjustable, controlled flow of the crushed rock material  50  to the conveyor belt  102 . An even, regulated feed of the crushed rock material  50  is important in obtaining uniform and predictable results from the apparatus  10 . 
     With reference to  FIGS. 5 and 6 , a lower portion of the hopper  405  includes a gate  420  and a movable door  430 . The gate  420  provides an opening for the material  50  to exit from the hopper  405 . The gate  420  opens to the interior holding portion  410  of the hopper  405 . The door  430  is in a movable engagement with the hopper  405  to close and open the gate  420  to permit, stop and regulate the flow of the crushed rock material  50  from the hopper  405  onto the conveyor belt  102 . One or more vibrators  450  may be positioned on or about the hopper  405  to vibrate the hopper  405  to assist in promoting the flow of the crushed rock material  50  from the hopper  405 , through the gate  420 , and onto the conveyor belt  102 . 
     The hopper  405  is generally positioned above the conveyor belt  102 . The gate  420  of the hopper  405  is positioned over the second end  107  of the conveyor belt  102  to drop or direct the crushed rock material  50  onto the second end  107  of the conveyor belt  102 . The hopper  405  may hold approximately 1 yard to approximately 100 yards of crushed rock material  50 , although the volume of the hopper  405  may be adjusted depending on the requirements of the apparatus  10 . Moreover, the volume of the hopper  405  may be adjusted to suit the specific application or eliminated entirely. Other systems and means may be employed to provide the regulated flow of the crushed rock material  50  to the conveyor belt  102 . The regulated flow of the crushed rock material  50  may come directly from the hopper  405 , a surge pile fed by a vibrating feeder, a cold-feed bin, a belt feeder, belt scales, or directly linked to an existing plant. 
     With reference to  FIGS. 2 and 3 , a spray system  500  is shown. The spray system  500  includes a tank  510  in fluid communication with a nozzle  520  via a fluid line  530 . A pump  540  pumps fluid from the tank  510  through the fluid line  530  and to the nozzle  520 , which sprays the fluid on a bottom, upper surface of the belt  102 . The nozzle  520  generally sprays most of or the entire width of the conveyor belt  102 . The fluid may include water, a wetting agent, or other solution that causes the fines  54  to stick or adhere to the conveyor belt  102 . The conveyor belt  102  should be sprayed with enough water to moisten the conveyor belt  102 . The amount of fluid sprayed onto the conveyor belt  102  is preferably adjustable in order to accommodate a light or heavy dampening of the conveyor belt  102  depending on the nature, e.g., the moisture, gradation, type of the feed material, and the specification of the desired end product. If too much fluid is sprayed on the conveyor belt  102 , then the discharging of the fines  54  may become sloppy and difficult to manage. 
     The fluid on the conveyor belt  102  provides for the extraction of the dust and fines from the crushed rock material  50 . The crushed rock material  50  directed or dropped onto the conveyor belt  102  includes the fines  54  that generally stick or adhere to the conveyor belt  102  and are moved upward on the conveyor belt  102  toward the second end  107 . 
     The coarse particles  58  of the crushed rock material  50  generally tumble or roll down the conveyor belt  102  toward the first end  106 . The fines  54  ride on the conveyor belt  102  up and over the head pulley  153 , where the scraper  200  scrapes the fines  54  from the conveyor belt  102 . 
     The conveyor belt  102  is generally flat and linear in shape. In other embodiments, the conveyor belt  102  may have a troughed shape on its top surface  104  to better retain the flow of the crushed rock material  50 . The conveyor belt  102  is generally continuous between the first end  106  and the second end  107 . The conveyor belt  102  has a generally smooth surface, i.e., the conveyor belt  102  is free from protrusions or other structures on its top surface  104 . 
     The conveyor belt  102  may have a width of approximately 1 foot to approximately 5 feet. The conveyor belt  102  may have a length of approximately 4 feet to approximately 30 feet. One of ordinary skill in the art will recognize that these dimensions may be varied (scaled up or down) to accommodate the quarry conditions, the loading and receiving equipment, the amount of the crushed rock material  50  requiring processing, and the processing rates required for the crushed rock material  50 . The conveyor belt  102  may be made from a rubber or an elastomeric material. The conveyor belt  102  may be reinforced with other materials to improve durability. A vulcanized or seamless conveyor belt  102  will often provide more efficient results without wearing on the scraper  200 . 
     With reference to  FIGS. 3 and 7 , the scraper  200  is in generally close contact with the conveyor belt  102  with little or no gap between the edge of the scraper  200  and the conveyor belt  102 . Preferably, the scraper  200  is positioned on the bottom surface  105  of the belt  102  at or near the second end  107 . By scraping the bottom surface  105 , gravity assists in causing the scraped fines  54  to fall away from the conveyor belt  102 . The scraper  200  physically scrapes the fines  54  from the bottom surface  105  of the conveyor belt  102 . The scraper  200  directs the fines  54  into the discharge chute  250  that directs the fines  54  away from the apparatus  10 . In the alternative, the scraper  200  may direct the fines onto a conveyor, vibrating feeder or other device that directs the fines  54  away from the apparatus  10 . The discharge chute  250  may also be in communication with a further conveyor system or other transport system to move the fines  54  away from the apparatus  10 . 
     The scraper  200  should have a width approximately the same width as the conveyor belt  102 . The scraper  200  may be one continuous length or in staggered, overlapping shorter lengths that clean or scrape most of or all of the entire width of the conveyor belt  102 . 
     The conveyor belt system  100  generally positions the conveyor belt  102  at an angle of approximately 25° to approximately 65° relative to the ground. This provides a sufficient angle such that the coarse particles  58  roll or fall down the conveyor belt  102  instead of being carried up and over the second end  107  of the conveyor belt  102 . Certain embodiments include the conveyor belt  102  at an angle of approximately 40° to approximately 50° relative to the ground. 
     The conveyor belt  102  is moving in an opposite direction of the flow of the coarse particles  58 . The motor  150 , via the head pulley  153 , moves the conveyor belt  102  at approximately 2 feet per second to approximately 20 feet per second. This rate of travel is sufficient to remove the fines  54  from the coarse particles  58  on the conveyor belt  102  of approximately 20 feet in length. One of ordinary skill in the art will be able to scale the apparatus  10  up to larger embodiments to process more crushed rock material  50  or vary the speed of the conveyor belt  102  to accommodate different materials. Preferably, the speed of the conveyor belt  102  is variable to accommodate different feed sizes, gradations, desired amount of fines removal, end-use specifications and output volume. 
     The belt adjusting system  190  and its belt angle adjuster  194  may be variably adjusted depending upon the crushed rock material  50  that is being processed by the apparatus  10 . Generally, the angle of the belt  102  may need to be increased for finer crushed rock material  50  in order to reduce unwanted carryover of coarse particles  58 . Further, the speed of the motor  150  may be increased or slowed down depending upon the nature of the crushed rock material  50 . Generally, the speed of the motor  150  may need to be increased for finer crushed rock material  50  in order to reduce unwanted carryover of coarse particles  58 . 
     The wetting of the belt  102  provides a wicking action to provide for the fines  54  to stick or adhere to the conveyor belt  102 . The action of the coarse particles  58  tumbling, rolling or flowing down the conveyor belt  102  provides many opportunities to separate the fines  54  from the coarse particles  58  and its surfaces, as the coarse particles  58  contacts the belt  102  multiple times. Some of the fines  54  may be adhered to the coarse particles  58 , and the wicking action of the wet conveyor belt  102  draws the fines  54  to stick to the wet conveyor belt  102 . 
     The apparatus  10  and methods described herein provide for the separation of materials that are generally of the same type. For example, the fines  54  and coarse particles  58  are both made from limestone. The methods and the apparatus described herein are generally used on a dry crushed rock material  50 . The methods and apparatus provide for loads of the crushed rock material  50  that may be out of specification for a particular construction application, by virtue of an excess fines content, to be processed and re-processed until the fines content is sufficiently reduced. For example, a load of the crushed rock material  50  with an excessive fines content may be repeatedly processed in the apparatus  10  until the fines content is sufficiently lowered. 
     The fines  54  removed from the coarse particles  58  may be used for many purposes, including, for example, as a fill material, a soil amendment, a mud-jacking medium, mineral filler in asphalt, or a landscaping material. Limestone dust may also act as a natural insecticide. 
     The following examples describe the use of the apparatus  10  and its ability to reduce the fines content of crushed rock. Table I shows the sieve sizes used to analyze the gradation of the crushed rock material. 
     
       
         
               
               
             
           
               
                 TABLE I 
               
               
                   
               
               
                 SIEVE SIZE 
                 INCH OPENING 
               
               
                   
               
             
             
               
                 ⅜″ 
                 .3750 (⅜″) 
               
               
                 #4 
                  .187 (approx. 3/16″) 
               
               
                 #8 
                 .0937 (approx. 3/32″) 
               
               
                 #16 
                 .0469 (approx. 3/64″) 
               
               
                 #30 
                 .0232 
               
               
                 #50 
                 .0117 
               
               
                 #100 
                 .0059 
               
               
                 #200 
                 .0029 
               
               
                   
               
             
          
         
       
     
     Table II shows the results of a gradation analysis performed on a ¼ inch clean dry screened crushed limestone material. Samples of the crushed limestone were analyzed before processing with the apparatus  10  using the sieves identified in Table I, and the results shown are in the “input material” column of Table II. After processing with the apparatus  10 , the crushed limestone was again analyzed using the sieves identified in Table I with the results shown in the “output material” column of Table II. The output material is the “cleaned” finished product separated from the by-product material, i.e., the fines. 
     
       
         
               
             
               
               
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE II 
               
             
             
               
                   
               
               
                 ¼″ CLEAN DRY SCREENED CRUSHED LIMESTONE 
               
             
          
           
               
                   
                 PERCENT BY WEIGHT PASSING 
                   
               
             
          
           
               
                 SIEVE OPENING 
                 Input Material 
                 Output Material 
               
               
                   
               
             
          
           
               
                 ⅜″ 
                 100 
                 100 
               
               
                 #4 
                 81.1 
                 80.5 
               
               
                 #8 
                 25.0 
                 13.2 
               
               
                 #16 
                 10.6 
                 6.1 
               
               
                 #30 
                 9.1 
                 5.2 
               
               
                 #50 
                 8.5 
                 4.8 
               
               
                 #100 
                 8.1 
                 4.6 
               
               
                 #200 
                 7.3 
                 4.3 
               
               
                   
               
             
          
         
       
     
     As shown in Table II, the −200 content of the crushed limestone has been reduced from 7.3% by weight in the input material to 4.3% by weight of the output material. The crushed limestone could optionally be processed again with the apparatus  10  to further lower the −200 content. 
     Further tests were conducted on a ⅜ inch clean dry screened crushed limestone material and the results are shown in Table III. The results shown in Table II and III illustrate how the apparatus  10  may be used to remove additional fines from crushed rock that has already been dry screened. Often, dry screened rock falls “out-of-specification” because the dry screening process does not sufficiently remove the fines. 
     
       
         
               
             
               
               
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE III 
               
             
             
               
                   
               
               
                 ⅜″ CLEAN DRY SCREENED CRUSHED LIMESTONE 
               
             
          
           
               
                   
                 PERCENT BY WEIGHT PASSING 
                   
               
             
          
           
               
                 SIEVE OPENING 
                 Input Material 
                 Output Material 
               
               
                   
               
             
          
           
               
                 ⅜″ 
                 100 
                 100 
               
               
                 #4 
                 14.5 
                 13.3 
               
               
                 #8 
                 5.1 
                 3.3 
               
               
                 #16 
                 4.5 
                 2.8 
               
               
                 #30 
                 4.3 
                 2.7 
               
               
                 #50 
                 4.1 
                 2.7 
               
               
                 #100 
                 4.0 
                 2.7 
               
               
                 #200 
                 3.6 
                 2.4 
               
               
                   
               
             
          
         
       
     
     As shown in Table III, the −200 content of the crushed limestone has been reduced from 3.6% by weight of the input material to 2.4% by weight of the output material. The crushed limestone could optionally be processed again with the apparatus  10  to further lower the −200 content. 
     Table IV illustrates the use of the apparatus  10  on a material made of the end-product fines removed by conventional dry screening processes, generally a ⅛ inch minus dry screened crushed limestone. The end-product fines, after being processed to a consistent gradation, are saleable for manufactured sand. As shown in Table IV, the −200 content of the crushed limestone has been reduced from 31.6% by weight of the input material to 8.7% by weight of the output material, thus improving the consistency of the gradation of the material. 
     
       
         
               
             
               
               
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE IV 
               
             
             
               
                   
               
               
                  1/8 ″ MINUS DRY SCREENED CRUSHED LIMESTONE 
               
             
          
           
               
                   
                 PERCENT BY WEIGHT PASSING 
                   
               
             
          
           
               
                 SIEVE OPENING 
                 Input Material 
                 Output Material 
               
               
                   
               
             
          
           
               
                 ⅜″ 
                 100 
                 100 
               
               
                 #4 
                 100 
                 100 
               
               
                 #8 
                 96.6 
                 93.3 
               
               
                 #16 
                 72.3 
                 53.6 
               
               
                 #30 
                 57.1 
                 27.7 
               
               
                 #50 
                 38.9 
                 14.0 
               
               
                 #100 
                 38.9 
                 11.0 
               
               
                 #200 
                 31.6 
                 8.7 
               
               
                   
               
             
          
         
       
     
     For the processing described in Tables II, III, and IV, the conveyor belt  102  was set at 42 degrees elevation and the conveyor belt  102  was moving at a speed of 372 feet per minute. The conveyor belt  102  used was 24 inches wide (19 inches between edges of the flashing material) and 6½ feet long. As described above, the width and length of the conveyor belt  102  may be sized up for full-scale processing. 
     It should be understood from the foregoing that, while particular embodiments of the invention have been illustrated and described, various modifications can be made thereto without departing from the spirit and scope of the present invention. Therefore, it is not intended that the invention be limited by the specification; instead, the scope of the present invention is intended to be limited only by the appended claims.