US1068162A - Pneumatic concentrating-table. - Google Patents

Description

G. Q. PAYNE. PNEUMATIG CONGENTRATING TABLE.

APPLICATION FILED AUG.14, 1912.

4W: :w51 .w y r ffl/@Mures *o (Lau/w? gli? cmnncn e. aYNE, on NEW Your., N. Y.

mamario concnnrnarmaraam Specilication of Letters Patent. applica/non mea august 14, 191e. semi no. 71am.

Patented july 22, 1913.

To all wlzbm may concern e it known that l, CLARENCE Q. PAYNE,

a citizen of the United States et America, residing in the boroufgh of Manhattan, city,

county, and State o New York, have invented certain new and useful Improvements in Pneumatic Concentrating-Tables,-

of which the following is a lull and true description.

My invention relates to improvements in that type ol concentrating table which sepaby' air" under pressure, While being' subjected to lmechanical agitation.

lt consists in the combination ol a novel' and improved form et table-top With improved means for separating minerals of didere'nt specilic gravities, alter they have been arranged in layers or strata by means' ol air pressure and mechanical agi-tation, upon the surface of said table-top.

ile the pneumatic or dry table is able to secure goodresults in separating minerals oit dierent specic gravities, especially alter vcareful sizing, .its usefulness has heretofore been much-y retarded by the diHiculty ol removing the separated products from the table in a clean condition after they have been arranged in distinct strata by the action of air currents and mechanical agitation, and also by the lack of durability of the pervious table-top 1 upon which the separation ot the ore-mixture takes place. v

ln an application led comcldent-ly,Wlthy this and bearing Serial No. 715,006, filed August 1l, 1912, I have described and claimed a novel medium for thepervious top of a pneumatic` concentrating table,-

whereby amore eicien't and satisfactmy separation is obtained than has heretofore been possible.

In the accompanying illustration Figures l and 2 show in plan and sectional elevation, respectively, a concentrating table in which cross section of the table top.l

In Figs. 1 and 2 the concentrating table is supported upon a foundation frame of channel-irons 10, by means of three levers and brackets 11,- 1l. Two of these are placed at the head or feed-endeo the table, and one at the discharge end, in ore der to secure a smooth reciprocatin motion fof the table Without disturbing vibrations due to unevenly loaded supports. The iframe ol the table may be constructed `of channel-irons 1Q. Below the frame of the f'tahle' is a' ll-'shaped sheet iron bottom 13, ,With square ends'. This is closely riveted 5to` the, channel-'iron frame so as to make air-'tight joints.

rlhe table-top lll as shown in Figs'. 2 and 3 is composed of porous silicd plates, 0r a? like minera-l septum, through' which air under pressure ismade to' pass'.v These plates @are cemented together a't their joints, and' are held by light T irons 33 to the channel- 1iron trame of the table Their upper surifaces thus formth top orl deck ofthe table upon which the. separation takes place'. This form of table-top isshown' somewhat imo're clearly in vieW. Air is admitte to the under side of the concentrating table by means of a pipe 15;', which is connected vvlth aV pressure fang," not shoWnv in the The table isgiven a 4suitaable inclination' Y ,direction ci its len"hl,` so as to canse the slnoot-hiy' lengthwise, While it is given ,a shaking mot1on. The inclination may be' varied@ by raising o r aweg embase of the vhimaged-lever which supports the lovverend of the table,but in general the inclination -Lwill not vary for the sameclass of material, and willy be merely suicient to permit'the different minerals composing yit to become `Well stratified as they travel down the table.

Any convenient t liead-'motionl mecha-l Fig. 3,- by a cross. sectional fmaterial fed upon t= e upper end to travel' 4my invention is embodied. Fig. 3 shows af nism may be employed, such as that shown nected tothe table by means of the connecting-rod 21. To absorb the shock of the `rapid reversal of the table, a spiral spring 32 is so placed between the angle-lever and a fixed abutment at the upper end of the headmotion frame' as to form an extension of the connect-ing lever.' The compression" of the spiral spring can be varied by means of a suitable bolt and nuts 22. The amount of motion imparted to the table may also be varied within certain limits by means of the screw adjustment 23, which permits the upper abutment of thef'toggle-lever 17 to be moved horizontally. In general, the amount of motion given to the table will vary with the degree of fneness of the materials to be treated, but will usually amount to one half inch or one inch in total throw. The speed of the table, or number of shakes per minute, will vary in general between 200 and 300.

The table is fed atl its upper end, and for its full width, in any convenient manner as shown in Fig. 2 by a feed-hopper 24, with a gate and feed roller. As the ore-mixture is caused to travel lengthwise of the table, the combined eect of the upward air-currents through the line pores or openings of the' table top, and the shaking mot-ion o-f the table, causes the minerals of the ore-mixture to separate and to form distinct strata, or layers, the heavy mineral forming the lower layer, while the light mineral forms the upper layer. Diagonal guides or banking strips 30, 30, and 31, '31, may be employed to narrow and thicken the ore-sheet at intervals lengthwise of t-he t-able, in order to assist in stratifying its minerals by increasing their agitation. These banking strips do not accomplish the same purpose as riiiies which are commonly used with wet tables, and whose function is to aid the separation by subdividing the ore-sheet. In my invention the separation is effected by mass action, and it is thus broadly distinguished from that accomplished by shaking tables which use water as a medium of separation. In the latter case the use of riiiies is of advantage.

At the lower end of the table diagonal guide- pieces 25, 25 may be so placed as to appreciably narrow the discharge line of the ore-sheet. These guides serve to thicken the ore-sheet gradually up to. the discharge point, and thus to permit the separation of the layers, or strata, of dierent minerals to be conveniently made along superposed levels, by means of the division plates 26, 26. The guides 25, 25, are extended in a parallel position a certain distance beyond the lower end of the table, and form, with a suitable bottoni, a trough which carries the separated ore well beyond the lower edge of the table. This discharge-spout or trough hasthe eX- tension pieces 27, 27 attached to its sides, and these carry the movable division-plates 26,` 26, which are superposed. The front edges o-f the plates 26, 26, may be raised and lowered by the screw bolts and nuts 28, 28, which are supported bv the brackets 29, 29.

For purposes of illustrat-ion,'F ig. 2 shows Ain sectional view a layer of ore upon the table-top which contains a heavy mineral and a light mineral, which have been'stratilied in layers by the air-currents passing through the table-top,'a.nd by mechanical agitation due to the shaking motionvof the table. The position ofthe light gangue mineral is shown by the shaded section at the upper part of the ore-sheet, and the heavy mineral by the unshaded portion below it. In order to remove clean concentrate and tailing from the table, the positions of the division-plates are so' adjusted that the dividing line between the two mineral strata falls between the upper and lower `division-plates. This space may be varied, and it pei/'mits compensation to be made for irregularities in the ore composition and in feeding. The product removed between the two division-plates constitutes a middling. That removed below the lower division-plate is the concentrate, or heavy mineral, while thatremoved above the upper division-plate is the tailing, or light mineral. The separat-ion of the various products is thus made along superposed levels. The

products of the separation are propelled forward by the shaking motion of the table, and are collected in separate chutes as indicated in Fig. 2. then returned to the same or a separate table for re-treat-ment. It thus becomes possible by means of superposed discharge openings, as described, to remove clean separated products from the table, and at the same time to maintain a large capacity of treatment.

The operation of my table is as follows: Air from a pressure fan is conveyed through the pipe 15 to the air boX 13 below the table, and is then allowed to pass through the pervious table-top under a regulated pressure. t the same time, the table is given a rapid reciprocating motion by-means of `the headmotion mechanism, driven by a belt from an outside source of power. rThe material to be separated is fed in a dry state in a regulated stream from the hopper 24 across the full widthl of the table-top la. Where the porous The middling product may beV `the particles to a predetermined ratio. This ratio will depend upon the diference in speciiic gravity between the heavy and light minerals in the ore-mixture Which'is to be separated. The greater the diierence in specilic gravity between minerals, the less. closely need the material be sized before separation, and vice versa. While traveling down the inclined surface of the table, the combined action of the upward air currents and the mechanical agitation of the particles, due to the shaking motion of the table, causes the heavier particles to settle through the agitated mass, and torni the bottom layer of the ore-sheet resting `on the table-top. 'lhe lighter particles, on the other hand, work their way upward and form the top layer of the ore-sheet, as indicated approximately in cross section in Fig 2. As fthe stratified minerals reach the lower end of the table, they encounter the guide pieces 25, 25, which narrow, and correspondingly thicken, the ore-sheet at its discharge end. this way the dividing line between the concentrate and tailing is made comparatively short, and by removing a small amountot middling product at the junction las between the strata, a large amount of clean concentrate and clean tailing can be removed by means of the superposed division plates, whose positions can be accurately adjusted. 'lhe middling product may be retreated upon the same or a separate table after a preliminary crushing, which is necessary, in case the product contains a large amount of true middling, z". e., attached particles which require further crushing to unlock them. In case the ore-mixture contains more `than two minerals to be Separated, it is tpossible to employ three or more ,division plates, or preferably to collect two of the minerals in a single group as a first step, and then reseprate the group upon :i separate table.

y invention is clearly distinguished from that type of pneumatic concentrating table inwhich thediiferent minerals are separated after being stratified, by spreading them outin thin bands upon the surface of a transversely .inclined table', and which are discharged at d/ierentpositions along the end and lower side of the table.

`-It is also distinguished from that type of 'tion of the ore-mixture.

'separate the stratit careful adjustment in order to obtain good results in separation, for the reason that the division plane between the concentrate and tai-ling occupies -a wide'space on the table, and its position may be easily shifted owing to slightirregularities inoperation. By my i invention, on the contrary, 'the length of the division plane between the concentrate and tailing can be Vmade extremely short, and its position can be maintained undisturbed with only a slight amount of vertical shifting duc to variations in the composilt is possible in this way to remove the separated products from a pneumatic concentrating table in a cleaner condition after they have been stratified than has heretofore been possible.

Having thus described my invention, Iy

claim:

lnIn a pneumatic concentrating table, a table-top porous to air under pressure, consisting of a plate of accreted mineral particles forming a mineral septum, in combination with means for feeding the material to be separated upon said table-top, means for passing air through said mineral scptum, means forreciprocating said table-top= and means for separating the stratified minerals contained the material along superposed levels, substantially as described.

2. In a pneumatic concentrating table, a table-top porous to air under pressure, con- .sisting of a plate of accreted mineral particles forming a mineral septum, in combiv nation with means for feeding the material to be separated upon said table-top, means for passing air through said mineral scptum, means for reciprocating said table-top, guides placed diagonally to the line of travel of the feed-sheet along the table-top to thicken said sheet at its discharge point, and division plates alon superposed levels to minerals contained in the material, substantially vas described.

3. In a pneumatic concentrating table, a table-top consisting of a mineral septum porous to air under preure, in-combination with means for reciprocating said table-top whilein an inclined positlon, means for feeding the material to bevseparatcd upon said table-top, means for passing air through ,along the table-top, and division plates alongr superposed levels at the/ dischargev vedge of the table-top to remove the separated minerals contained in the crude material, substantially as described.`

4. In a pneumatic concentrating table, a

A table4top porous to air under pressure, consisting of plates ofaocretcd mineralY particles forming the-top of an inclosed box, in

'combination with means' for passing airy from said boxthrough the porous mineral the stratified minerals contained in the Ina,-

tab'le-top, meanls o reci'nocacingrl said1 bo terial, substantially as described.

W 11 e 1n an inc lne posi lon, u1 es p ace diagonally to the line of travegl of the feed CLARENCE Q' PAYNE' 5 sheet along the table-top to thicken said Witnesses:

sheet at its ldischarge point, and division WALTER S. JONES,

plates along superposedk levels to separate OLIVER M. PENNINGTON.

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