Show the no 5 3 concentrator the allis chalmers company of chicago ill III has perfected its new no 3 concentrator and this up to date and modernized ore dresser is now on the market and on exhibition at the companas comp anys salt lake office for the benefit of our readers we take pleasure in describing this table its operation and its points of ad vantage advantage in the manufacture of this concentrator all the good features in the original design of the table have been retained and the improvements adopted embody many distinctly new and important features of design table action and arrangement of riffles fiffles rif fles description the table is now constructed of structural steel and iron throughout with the ex this motion has more action on the particles of mineral as they are in closer proximity to the table surface than on the lighter gangue or silica which remains on top of the mineral the flow of the wash water transverse to the reciprocating motion produces a greater movement of the gangue or silica than of the mineral particles owing to the difference in specific gravity and washes the particles of the lighter gangue a farther distance in a given time As the gangue is on top of the mineral it is acted upon more freely by the wash water until final separation takes place of these three forces gravity acts in a vertical line the reciprocating motion and flow of wash water in nearly transverse hor k mv NEW pg A k NEW NO 3 concentrator COMPLETE caption of the table top this construction has given the table great rigidity of frame with a greatly increased smoothness of table action the no 3 table has a new motion the means employed for this end are rocking arms the table top rests on four long rollers extending the whole width of table and giving over twenty four feet of bearing surface also double tapered riffles fiffles are used in concentrating mineral particles on a table three forces are employed viz gravity reciprocating motion and flow of wash water v a t e r gravity acts on the mineral particles forcing them downwards the heavier particles occupying the lower stratum the reciprocating motion of the table tends to bring the particles of ore forward 1 in the direction of the line of I 1 lines the component of the two horizontally acting force is a line diagonal to both consequently the travel of the material both mineral particles and gangue is in a diagonal direction hence the table is built diagonally to the reciprocating force and to the flow of the wash water A corollary of the foregoing proposition is that nearly all of the available surface of a diagonal table is effective surface the large effective surface diagonal to the reciprocating ro motion and flow of the wash water results in a largely increased capacity and cleaner separation owing to the greater transverse distance the material travels on the table long feed box the advantages of a long feed box are many the feed box on the table I 1 measures six feet and is attached to fd and is a part of the table A short feed box of necessity deposits the feed on the table in a limited area creating a heavy and rapid flow of the water contained in the feed with a consequent loss of the finest of the pulp at the very beginning of the process on the other hand a long feed box attached to the table receives the reciprocating motion distributes the feed evenly over a large surface and also as a result of the shaking this box becomes an especially efficient effic c I 1 e nt sizer in itself the long feed box is placed on the side along which the mineral travels i 1 e the natural line the mineral takes when acted on by the reciprocating motion and the wash water the feed box is also constructed so as to give a partial concentration on a mixed feed it will collect the large round mineral which has a tendency to roll if let on to the table direct and discharge it through an opening in the forward end of box leaving lea ving this material high up out of danger an additional advantage of the lon long feed box is found in the utilization odthe of the water contained in the feed as wash water this makes a saving of clean wash water where water is scarce this is a v valuable consideration era tion I 1 the head motion the head motion of the no 3 table has been completely redesigned and has been proven to be the best motion for imparting quick movement to mineral particles on a table surface the adjustment on the head motion has been provided with stops so that it cannot be adjusted too far up or down or cause breakage by extreme angles of rocker at the lowest position of the adjusting block and screw the table has a stroke of 9 16 inches at the highest point of adjusting block and screw the stroke is 1516 15 16 inches A medium position of block and screw gives a stroke of three fourths of an inch the motion is imparted to the table by means of rocking arms at the head and tail end of the table the rocking arm at head end is connected with the head motion by means of a connecting rod and cast steel yoke the rocking arm at the concentrate discharge end of table engages the spring which is held in an adjustable spring seat both rocking arms have chilled surfaces where they press upon the table puller castings which are bolted to the under side of the table at both ends between the main longitudinal wooden members of the table top these table pullers bullers also have chilled surfaces the rocking arms are carried on steel shafts in boxes bolted to the lower flanges of the nine inch channels the table is always in tension by means of the spring at one end and head motion at the other acting against the table pullers bullers through the rocking arms which imparts the smoothest motion yet devised for a table top the movement is perfectly quiet smooth and noiseless the entire weight of the table resting on the rollers arrangement of the riffles fiffles Rif fles the riffles fiffles all end on a line at right angles with the line of reciprocation the riffles fiffles are made of either rubber or a light copper angle whichever style is preferred the special feature of the riffle used on the no 3 Over concentrator for handling fines and slimes is that they have a double taper the riffles fiffles at the head end of the table start at a height of 1 32 inch increasing in height with an even taper upwards until they reach the height of 3 16 inch at the end of the feed box or in a length of six feet from this point the rif fles diminish in height to a feather edge at about twenty inches from the concentrate discharge end of table this special shape and design of riffle has been adopted as best both in the practice and theory of concentrating fine mineral particles for the following reasons the practical reason in practice it is a well known fact that the fine mineral particles contained in the dirty water of feeds are more readily caught if the dirty water runs over a silica bed of somewhat larger size than if the dirty water containing slimes runs over empty riffles fiffles rif fles which have a tendency only to agitate the fine slimes and as they have no protecting bed of loose coarser silica or sand to protect them from the following water in the feed they are carried away and lost if however a wide and thin bed of silica can be maintained in the path of the dirty water containing the slimes then whatever portion of these slime particles settle down on and through this wide and open bed of silica is saved and brought forward the backward tapering raffles of the Over concentrator are used to provide this wide bed of silica or sand in the path of the feed water with slimes in practical operation the back of the tapering riffles fiffles distribute the sand or silica evenly over the table and cut down the area of discharge of the dirty water alone to fifteen inches on tailings discharge side of table as compared with an area of discharge of dirty water alone of eight feet in tables using rifles highest at back end of table tipping adjustment the tipping of the table is accomplished by means of iron wedges the wedges are connected by a rod under the table toa a screw and hand wheel or when this meth of adjustment is not convenient the rod carries a rack and the wedges are by a rod under the table to a screw and hand IvI wheel leel placed conveniently on the upper side of table the upper wedge raises the upper corner of the table and the opposite wedge at the same time lowers the lower corner of the table or vice versa the total range of adjustment is five inches the shipping weight of the table boxed and crated ready for shipment is 2 2750 pounds |