US1073644A - Separating-table and process of separation. - Google Patents

Description

H. M. SUTTON & W. L. & E. G. STEELE.

SEPARATING TABLE AND PROCESS OF SEPARATION.

APPLICATION FILED AUG.17,1911.

. 1,073,644. Patented Sept. 23, 1913.

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2 gym H. M. SUTTON & W. L. & E. G. STEELE. SEPARATING TABLE AND PROCESS OF SEPARATION.

APPLIUATION FILED AUG. 17, 1011.

Patented Sept. 23, 1913.

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Hal/5y (inflow, IN VEN Tom" .Edw W64: Jd'eele H. M. SUTTON & W. L. & E. G. STEELE.

SEPARATING TABLE AND PROCESS OF SEPARATION. APPLICATION FILED AUG. 11, 1011.

1,073,644, Patented Sept. 23, 1913.

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H. M. SUTTON & W. L. & E. G. STEELE. SEPARATING TABLE AND rnocrss 0F SEPARATION.

. APPLICATION FILED AUG.17, 1911.

1,073,644. Pa nted Sept. 23. 1913.

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WaQe/l. weeza fideuze WITNESSES CZNQM /AZ m INVENTORJ v UNITED STATES PATENT OFFICE,

HENRY M. SUTTON, WALTER L. STEELE, AND EDWIN G STEELE, OF DALLAS, TEXAS.

SEPABATING-TALBLE AND PROCESS OF SEPARATION Specification of Letters Patent.

Patented Sept. 23, 1913.

Application filed. August 17, 1911. Serial No, 644,492.

To all whom it may concern:

Be it known that we, HENRY M. SUTTON, WALTER L. STEELE, and EDWIN G. STEELE,

citizens of the United States, residing at Another object of the invention is to provide the banking bar with gates in order to allow a certain proportion of the heavy; components to be released in order to pass:

' into the'delivery chamber from which they are discharged; the main feature of this; invention being to retain a certain proportion of the heavier components in a zonei extending parallel with the banking bar to I form an obstruction until a back pressure of I the heavier particles is maintained against the entire bulk of the pulp, and to enable; concentration or separation to be efl ected without previous close classification of the;

particles to travel over its surface against a pulp or mixture.

Another object of the invention is to treat 1 pulp of larger size particles tha'nis possible on any other concentrating device of its a movement of the table required to produce class.

Any means which willobstruct the move ment of the heavier constituents of the mass or pulp transversely to the thrust or propelling movement of the table ream-be used, the object being to cause theulreavier particles to bank against the banking bar provided with gates or openings to permit their passage therethrou'gh. This banking bar is the main feature of our invention, as it collects against itself those particles, large and placed across the line or travel ofthe heavier constituents of the pulp, which are more responsive to the propelling action of the table than to the transverse movement of the lighter particles by gravity alone, is that the finer particles of the heavier constituents of the pulp or mixture are caused to bank against same together with the larger particles of the heavier constituents thus allowing the larger particles to protect the smaller ones and to hold same against the bar so that the fine particles of the heavier constituent are the first released through the openings in the bar into the delivery chamber.

It is well known to those skilled in the art of ore dressing, where the values are to be recovered from the ore by mechanical con centration depending on the difi'erenc'e in specific gravity of its various components, that hereinbefore a classification was required or what is more commonly termed sizing of the comminuted particles to a relatively equal size is essential before attempting concentration or separation of its values from each other or from the waste components thereof upon the usual form of concentrating apparatus. The reason for this is quite ap arent if one considers what would be the e ect if particles of comminuted ore of all sizes were delivered to the usual form of shaking concentrating table to cause the force of wash water which is either delivered at an angle to the travel of ore or directly against the same. The force of water and weight. The larger particles of ganguc remain in a stratum over the smaller and valuable components of the pulp, thus prevent ing the separate collection of the valuable pending for separation upon the difference in specific gravity in the particles by either wet or dry methods. This we overcome by our improved invention as we avoid the necessit'y of sizing or classifying the pulp within wide limits and it is possible with our method of separation to separate from the pulp the valuable mineral particles from the refuse or gangue where the range in size of the particles treated would not be per missible with the ordinary concentrating apparatus. As an example, particles of pulp varying in size from one-sixth of an inch to one-eighteenth of an inch can be successfully treated at one time where the specific grav ity between the valuable components of the pulp and gangue would be as close as one point'or one and one-half points, and where the difference in specific gravity is greater, it is, of course; understood that a greater range in the sizeof the particles. of the pulp can be treated. With our improved apparatus, the heavier particles and the lighter particles in the vicinity of the banking bar, instead of overlying each other as is the case with concentrating apparatuses now in use, arrange themselves in vertical walls to each other, the heaviest particles banking against the banking bar, the width ofthe zone 6f heavier particles against the banking bar being regulated by allowing alportion of the heavier particles to pass into the discharge chamber by. means of openings 'or gates provided in the banking bar. The object of the banking bar is to obstruct the travel of the entire pulp or mixture on the table in the direction of the thruster propelling action without obstructin its movement at an angle to the thrust 0% the table.

In the drawings-Figure 1 is a perspective view ofour improved separating .table showing the preferred form with three separating compartments; Fig. 2 is a perspective view of a portion of the table showing the line of travel of the material the heavier particles being shown by heav lines against the banking'bar and in the elivery cham-' ber; Fig. 3 is a transverse vertical section through the table; Fig. 4 is a top plan view of a portion of the table and banking bar showing the gate for controlling the passage of the heavier particles to the delivery chamber; Fig. 5 is a section taken on line 5-5 of Fig. 4; Fig. 6 is a section taken on line 64-6 of Fi 4; Fig. I is a top plan view of a portion'o the table showing rifles arranged thereon; Fig. dis a plan view of a modified form of table as disclosed in our former Patent No. 949,046, granted Decem- Lovaeaa ber 20,1910, showing the application of the banking bar Fig. 9 is a transverse enlarged section through a portion of the table shownism 5-through the medium of. a driving rod 6. The driving mechanism can be substantially as disclosed in our former Patent No. 898,020, granted September? 2, 1908, in order to obtain a slow advance and a quick return, or it can be any mechanism to impart a propelling movement to the material being treated.

The preferred form of table 4 comprises a rectangular frame and easing 8 in order to form an air chamber 9 whichis provided with connecting nipples 1 0 to which are connected flexible air inlet pipes 11 extending from a supply pipe 12 which may be connectedvto any source of supply in order to maintain a uniform air pressure within the chamber for the purpose later described. Arranged longitudinally within the frame are floor supporting ribs 13 on which is arranged'a pervious floor 14 of any suitable texture, and upon which the material is adapted to. be discharged and through which the airis adapted to pass in order 'is' provided with a rail 15 around three of its sides in order to maintain the material thereon and upon the open side an inclined delive shelf 16 is arranged having a retaining ar 17 under which are arrangedadjustable guide fingers 18 for guid' in the material from the table into suitab e receptacles.

Arranged'upon the floor of the table are partitions 21 and 22 dividingthe'table into three compartments, each partition being provided with an oblique portion 23, the outer rail being likewise provided with anoblique portion 24 which forms the outer wall of the end compartment. Extending diagonally across the table adjacent the partitions and end rail are banking bars 24' which form delivery chambers 25 between I the partitions and into Whichthe heavier particles are adaptedjzto passmdbe dischargedat the-,open end thereof on to the delivery. shelf in-thjeiusual manbizer. 1 :The

banlning bars 24 are formedsu a al y"- the same and a description of one will be sufiicient for all. The bar is arranged so as .to diverge from the oblique portion of the partition in order to form a discharge chamber with a discharge opening of greater size than the upper end thereof. The bar is provided with openings through which the heavier particles which have been collected against the bar pass into the delivery chamber, the discharge of the particles from the inner wall, or wall next to the separating chamber, of the banking bar to the delivery chamber being regulated by movable gates 26 which are provided'with stems 27 having springs 28 secured on their upper edges which engage bridgemembers 29 extending across the openings of the banking bar whereby the gate will be held .by frictional contact in its adjusted position in order to allow the desired amount of particles banking against the bar to pass through the openings. By the use of these gates, the zone of the heavier particles can be regulated on the inner side of the banking bar to suit the material to be separated.

An initial banking bar 30 is adjustably carried by a rod 31 and so arranged in respe'ct to the feed hopper that when the material is deposited upon the table, an initial banking is obtained in order to partially form a wall of the heavier particles by the thrust of the table. The table being on an incline, the natural course of the material fed upon the floor at the upper end of the table would be on transverse lines to the lower edge of the table. The natural travel of the material is overcome by the longitudinal reciprocation of the table to such an extent that the path taken by the ore, or pulp, is diagonal of the table in order to force the same against the diagonally arranged banking bar which retards the movement to such an extent that a wall of heavier particles is formed which has a tendency to retard or thrust back the lighter ones, the material at the same time traveling in the direction of the inclination of the table. In this manner, the heavier particles are formed in a separate and distinct zone from the lighter particles and as the zone of the heavier particles increases in size it forces back the lighter particles thereby completely obstructing the travel of the entire pulp at one place on the table in the direction of the thrust or propelling movement of the same, while at the same time allowmg the particles perfect freedom of movement at an angle to the thrust of the table, the pulp being subjected to the cushioning action of the air admitted through the pervious floor, retaining the heavy components on the floor, the next heaviest above that and the lightest u on the top so as to cushion the particles rom one another in order to allow them to slide from oil the other as they bank against the obstruction until the back pressure of the heavy particles is obtained against the entire bulk of the pulp on the table, the gates forming means for relieving the pressure at different points in the obstruction, and collecting the heavier particles.

In the majority of cases, the heavier particles of an orc pulp or mixture are the valuable components of the mass and in the heavier particles which bank against the banking bar are allowed to pass therethrough into the discharge chamber and are collected as a valuable concentrate. This would be the case when treating any ore or mixture in which the heavier particles of the mass constitute the values. When treating an ore or mixture in which the values lie in the lighter particles this operation is reversed, the heavier particles, in this case the waste, banks against the bar, passes into the discharge chamber and is discarded as waste, while the lighter particles of value are prevented from reaching the bar by the heavier particles, pass transversely across the table deck and are discharged as concentrates at its lower delivery ed e. The treatment of graphite, and simi ar pulps, belong to this latter class while most of the concentrating ores belong to the former.

In order to retard the natural course of the material fed upon the table when separating certain kinds of material, we have found that better results can be obtained by providing the floor with rifiles or other retarding means and in Figs. 7 and 9 We show a table constructed for obtaining this result. It was found that by, retarding the movement of the material in its natural course in order to allow the thrust of the table to have a greater effect upon the same, the heavier particles will be formed quicker into a zone along the banking bar in order to form a retarding wall against the entire bulk of the pulp on the table so' that the particles are only free to move at an angle to the thrust adjacent the obstruction formed by the heavier particles, thereby subjecting the heavier particles to the full action of the thrust of the table. To obtain this retarding of the movement of the ma; terial transversely across the deck, retarding means of three typesare used, each type having advantages over the others depending on the material being treated. One type is shown in detail in Fig. 9 where 35 is a riflle secured to deck su porting ribs 13 and 36 the pervious floor wit air retarding strips 37 ad'acent the riffies 35 and to the upper side t ereof. These air retarding strips are made of pervious material of less porosity than the pervious floor and form zones of ordinary operation of our invention the i reduced air pressure immediately above the rifiles. These zones of reduced pressure alholding and guiding the fine particles of the heavier constituent of the mass to the banking. bar. When treating material whose constituents have a wider difference in specific gravity this'reduce'd air pressure is not necessary and the air retarding strips are omitted, the ritlle above the table floor being sufficient'to form the desired obstruction to the transverse fiow or travelof the heavier particles of the mass.

When treating very fine pulp, .or when treating pulp whose. particles differ but slightly in specific gravity, the form of retarding means or air obstructing strip shown in our Patent No. 979,046, ranted December 20, 1910, can be used w ich consists of partially pervious strips under the table cover or floor in relatively the same position as the riflles- 35 to partially obstruct the passage of the air through the table floor, or of strips in the same position which totally obstruct. the air in order to form a series of dead zones on the'surface of the table floor. Referring to our Patent No. 979,04t3, page 3, lines 75 to 85, this type of retarding means is described as follows:

These air controlling strips may be of such' density as to totally obstruct the passage of air through them or modify its action as found desirable, and may be applied to the under surface of the floor as a strip or as a composition of such character as will not change the textile surface of the cloth upon the upper unobstructed surface of the table.

When the pulp, or mixture, is initially fed from the feed hopper 20 on to the table floor 14: the immediate effect of the air cushion is to stratify the pulp or mixture into horizontal strata, the heavier particles forming the lower zone of the massand the lighter ones on top according to their specific gravities. The propelling action of the table is exerted on the pulp in proportion to the weight of the particles, the heavier ones responding more to its action than the lighter ones or particles of less specific gravity. When the" heavier particles of the mass reach the banking bar their further travel in the direction of the table thrust is arrested and they bank against the bar and travel parallel therewith tdward the lower delivery edge of the table. At convenient points in the banking bar openings are provided to permit the passage of theheavier particles therethrough in order to regulate and control the width or zone of the heavier particles against the bar to form a wall of the heavier particles against .which the lighter particles may bank. Fig. 6 shows the arrangement of the particles against the banking bar 2a, 43* being the larger of the heavier particles and 44* the smaller particleslof same;- .45 shows the banking of the lighter particles against the heavier ones.-

The fine particles of the heavier constituent of the mass being treated, being of, the same specific gravity as the larger heavier particles, naturally travel therewith, and as they are less alfected by the cushioning action of the air passing through the pervious floor they travel below or under the larger particles and collect against the bar under the larger particles thus allowing the larger particles to protect the smaller ones, as stated. The action of the banking bar is to collect against itself those particles, large and small,'whosespecific gravity is greater than the lighter particles of the mass being treated. i

In Fig. 8, we show a modified form of table substantially as described in our Patent No. 979,046, granted December 20, 1910, which is circular in form and comprises a table 38 proper having a semi-circular banking vbar 39 provided with gate controlled openings 40 constructed in substantially the same manner as described in the preferred form of table, and we have found that by arranging a banking bar upon an oscillating table of this style, a zone of the heavy particles will be formedagainst the same in order to form an obstruction for the lighter particles in their line of travel.

In Fig. 10, we have shown a modified form of banking bar comprising a bar 42 which isarranged above the pervious floor of the table 43 so as to form an opening to allow the heavier particles to passinto the delivery chamber and this opening may extend the entire or a portion of the length of the banking bar and it will be seen that by using a bar of this construction we accommodate for discharging the larger portion ofthe-mass beingtreated and we have found that by allowing the heavier particles to pass under the bar the banking efiect will not be injured to any extent, the heavier particles forming a zone which will obstruct the lighter particles. If desired, suitable gates would be arranged at intervals on the banking bar to extend down to the pervious floor and partly close the opening therein in order to increase or decrease the zone of. the heavier particles adjacent thereto, or this apnoea type of bar can be adjustable vertically to regulate the width of the opening below same. The advantages of this t pe of bar is that when treating pulp, the arger proportion of which is composed of the heavier particles, the opening under the banking bar permits of more of the heavier particles passing the bar in a given time and to maintain the necessary zone of heavy particles against the bar. The main object is to maintain a certain proportion of the heavy components against the banking bar while releasing the greater proportion of the components into a delivery chamber, and various other means for accomplishing this result maybe employed without departing from the spirit of our invention.

In the above description, reference is made to the treatment of ores and minerals but we have found that our invention is not confined to the treatment of that class of material as our apparatus is equally adapted to the treatment of seeds and cereals, the treatment of coal, of drugs, or any pulp or mass of particles 'whose constituents differ in s eoific gravity.

e have described a preferred form of construct-ion showing three compartments but do not wish to limit ourselves to that type of apparatus as each compartment is a separate and distinct operating device with separat'efeeds but driven by one operating mechanism, and our invention can be constructed with one, or more, compartments, as may. be desired.

Throughout the specification and claims the terms completely obstructing and complete obstruction are used in order to differentiate the obstruction from the ordinary ritlle or dead'air space which only obstructs a certain portion of the mass allowing the other portion thereof to ride over the obstructed portion and form an overflow, while in our invention the sole novelty of the same is to provide an obstruction across the normal'movement of the material to prevent any overflow in order to obtain a back pressure upon the mass, whereby the partlcles will be separated into distinct zones.

Having described our invention and set forth its merits what we claim and desire to secure by Letters Patent is 1. A concentrating table having a pervious floor, means for reciprocating the table adapted to propel the material in a predetel-mined direction, an air chamber arranged under said floor, an obstruction arranged diagonally across the line of travel of the propelling moyement of the material forming an obstruction of concentrates free from direct passage in the line of imparted movement, and having passages at an angle to the 11118 of movement of t e material.

2. A concentrating table having a pervious floor, means for reciprocating the table adapted to propel the material in a predetermined direction, said table being inclined transversely to the imparted path of travel of the material, an obstruction arranged diagonally across the line of travel of the propelling movement of the material forming an obstruction of concentrates adjacent thereto free from direct passage in the line of imparted movement, and having passages at an angle to the line of imparted movement of the material.

3. The process of concentrating a mass of material, parts thereof having different characteristics, consisting in supporting the material upon an inclined support and in imparting to said material a positive movement across its path of travel by gravity, and forming an obstruction of concentrates beyond the strata of material containing tailings across the imparted movement of the material.

4. The process of concentrating a mass of material, parts thereof having different characteristics, consisting in moving said material in one path, imparting to said material a positive movement in a direction across said path, obstructing the material across the imparted movement thereof until a substantially vertical stratum of concentrates is established beyond the strata of the material containing tailings.

5. The process of concentrating a mass of material, parts thereof having different characteristics, consisting in supporting the material upon a surface by a gaseous cushioning medium, feeding said material in one path, simultaneously imparting to said material a positive movement in a direction across said path, and obstructing the material in the imparted movement thereof until a substantially vertical stratum of concentrates is established beyond the strata of material containing tailings.

6. The process of concentrating a mass of material, parts thereof having different characteristics, consisting in supporting the material upon an inclined surface by continuous air pressure to cause a gravital movement of the material upon said support, imparting to said material a propelling movementin a direction across the movement of the material by gravity, banking said material across the line of travel of the propelling movement until a substantially vertical stratum of concentrates is established beyond the strata of material contammg tailings.

7. The process of concentrating a mass of material, parts thereof having d fferent characteristics, consisting in supporting the material upon a surface by a gaseous cushioning medium, gravitally feeding said material in one path, imparting a propelling movement in a direction across the movement of the material by gravity,- and forming an obstruction of said material across the line of travel of the propelling movement of said material until a substantially vertical stratum of concentrates is established beyond the strata of the material containing tailings.

8. The process of concentrating material having components of different characteris tics, consisting in propelling the material in a predetermined direction, obstructing the travel of material in said direction until a substantially vertical stratum of concentrates is established beyond the portion of the material containing gangue and concentrates, and then causing a portion of said stratum to travel at an angle to the line of movement and then in line with such movement.

9. The process of concentrating material having components of different characteristics, consisting in supporting the material upon a surface by a gaseous cushioning me-' dium, propelling the material in a predeter mined direction, obstructing the travel of the material in said direction until a substantially vertical stratum of concentrates is es tablished beyond the portion of the material containing gangue and concentrates, and then causing a portion of said stratum to travel at an angle to the line of movement and then in line with such movement.

10. The process of concentrating material having components of difierent characteristics, consisting in propelling the material in a predetermined direction, obstructing the travel of the material in said direction until a substantially vertical stratum of concentrates is established beyond the portion of material containing gangue and concentrates, retaining the concentrates of said material collected adjacent the obstruction until a back pressure is maintained against the entire mass of material, and then causing a' portion of said stratum of concentrates to travel at an angle to the line of movement and their in line with such movement.

11. A concentrating table having an inclined pervious .floor, means for propelling the material in a predetermined direction, an obstruction arranged diagonally across the line of the propelling movement of said material at such an angle as to deeply bank the concentrates, presenting an obstructing surface free from direct passage in the line of imparted movement and having passages at an angle to said line.

12. A concentrating for propelling the material in a predetermined direction thereon, a deliverychamber arii-anged diagonally across the path oil the table having means propelling movement of the material forming an obstruction for deeply banking the concentrates and present-ing an obstruction surface free from direct passage in the line of imparted movement, and having passages at an angle to the line of imparted movement.

13. A dry concentrating table, means for imparting movement to the material in a predetermined direction, said table having a diagonally arranged delivery chamber forming an obstruction across the line of imparted movement ofthe material free from direct passage in the line of imparted movement, and having vertically extended passages and gates for controlling the flow of material through said passages.

14. A concentrating table, means for imparting a movement to the material in a predetermined direction, said table having a banking bar extending across the line of imparted movement at such an angle as to deeply bank the concentrates and presenting an obstructing surface free from direct passage in the line of imparted movement, and having passages at an imparted movement.

15. In a concentrating table, means for imparting movement to the material in a predetermined direction, a floor inclined transversely to the path of travel of the propelling movement of the material thereon, a banking bar arranged across the line of imparted movement at such. an angle as to deeply bank the concentrates free from direct passage in the line of imparted movement, and provided with vertically extended passages at an angle to the line of imparted movement.

16. In a reciprocating concentrating table, means for imparting movement to the material in a predetermined direction,v a pervious floor inclined transversely to the path of travel of the material thereon by the imparted movement thereof, in combination with an air chamber beneath said floor, means for supplying air thereto, and a banking bar arranged across the path of travel of the material by thepropelhng movement thereof, at such anangle'as to deeply bank the concentrates to form an obstructing surface free from direct passage in the line of imparted movement having passages at an angle to the line of imparted movement.

17. A reciprocating concentrating table, means for im arting movement to the material in a pre etermined direction, said table having a banhng bar arranged thereon atsuch an'angle as to deeply bank the concentrates across the imparted movement of the material thereon, said bar being provided with gate-controlled o enings forming pasangle to the line of t sages at an angle to t e line of the propel ling movement of the material thereon.

1437 same 18. A reciprocating inclined concentrating table, means for imparting movement to the material in a predetermined direction, said table having a bankin bar arranged diagonally across the line of the propelling movement of the material for banking the concentrates adjacent thereto, to form an obstruction free from direct passage in the line of imparted movement and having pas sages at an angle to the imparted movement, and means for controlling the movement of said material through said passages.

19. The combination with an inclined concentrating table, means for imparting movement to the material in a predetermined direction, of a banking bar extending across the table forming a delivery chamber having passages at an angle to the imparted movement of the material upon said table, said banking bar forming an obstruction of the concentrates free from direct passage in the line of imparted movement, and means for controlling the passage of the concentrates from said table into said chamber through said passages.

20. The combination with a concentrating table, of a banking bar arranged diagonally thereon having openings, bridge members extending across said openings, gates provided with stems extending through said openings, and springs carried by said stems engaging said bridge members for holding said gates in their adjusted positions.

21. A concentrating table, means for imparting movement to the material in a predetermined direction, said table having a delivery chamber arranged diagonally across the line of the propelling movement of the material, one Wall thereof forming an obstruction for deeply banking the concentrates and presenting an obstructing surface free from direct passage in the line of imparted movement and having passages at an angle to the line of imparted movement, and means for controlling the passage of concentrates through said passages into said delivery chamber.

22. The process of concentrating a mass of material, parts thereof havin diflferent characteristics, consisting in gravitally feeding said material in one path, retarding the movement of the material by gravity,v imparting to said material a positive move- 7 ment transversely of the movement of the material by gravity, and obstructing the material in its imparted movement until a substantially vertical stratum of concentrates is established beyond the strata of material containing tailings.

23. The process of concentrating a mass of material, parts thereofhaving different characteristics, consisting in feeding said material in onepath, retarding the movement of said material in said path, imparting to said material a positive movement m a direction across said path, obstructing the material in the imparted movement until a substantially vertical stratum of concentrates is established across the line of imparted movement beyond the strata of material containing tailings. I

24. The process of concentrating a mass of material, parts thereof having ditl'erent characteristics, consisting in supportin meterial upon a surface by a gaseous cus ioning medium, feeding said material in one path, retarding the movement of said material in said path, simultaneously imparting to said material a positive movement in a direct-ion across said path, and obstructing the movement of said material in the direction of travel by the propelling movement until a substantially vertical stratum of concentrates is established across the line of imparted movement beyond the strata of material containing tailings.

25. The process of concentrating from a mass of material, parts thereof having different characteristics, consisting in supporting the material upon a surface by a gaseous cushioning medium, feedin'gsaid material by gravity in one path, retarding the movement of said materlal in said path, retarding the air pressure at the point of material retardation, imparting to said material a propelling movement in a direction across the movement of the material by gravity, and forming an obstruction of said material across the line of travel of the propelling movement of said material until a substantially vertical stratum of concentrates is established beyond the strata of material containing tailings.

26. A concentrating table having an inclined deck, retarding members arranged across the path of travel of the material by gravity, means for imparting movement to the material in a predetermined direction upon said deck, a banking bar arranged upon the deck of said table across the line of ropelling movement of the material, at suc an angle as to deeply bank the concen-' trates and presenting an obstructing surface free from direct passage in the line of imparted movement and having passages of vertical extent substantially equaling the depth of the concentrates banked against said bar and extending at an angle to the line of propulsion, and means for controlling the movement of said concentrates through said passages.

27. The process of concentrating a mass of material, parts thereof having different characteristics, consisting in feedingcgaid material by gravity in one path and supporting the material upon a gaseous cushioning medium, impartlng to said material a movement across the line of movement of the material by gravity, banking the material across the line of imparted movement until a substantially vertical stratum of concentrates is established beyond the strata In testimony whereofwe affix our signatures in presence of two Witnesses.

HENRY M. SUTTON. WALTER L. STEELE. EDWIN G. STEELE.

Witnesses:

H. R. PERKINS, G. M. ANpERsoN.

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