US2762574A - Apparatus for preparing finely divided material - Google Patents

Description

J. C. LINCOLN Sept. 11, 1956 APPARATUS FOR PREPARING FINELY DIVIDED MATERIAL Filed Sept. 18, 1953 INVENTOR. JOA/A/ c. A/A/caLA/ APPARATUS FOR PREP G FINELY DIVEDED John Lincoln, Phoenix, Application September 18, 1953, Serial No. 381,077 7 Claims. (Cl. 241-78) This invention relates as indicated to an apparatus for preparing finely divided minerals and pertains more particularly to an apparatus which is particularly suited for the production of finely divided ores which need to be reduced to a finely divided state at one step in the processing thereof.

The apparatus of this invention is designed primarily to take the place of much more cumbersome and expensive equipment heretofore used and to simplify the overall operation, thus effecting a two-fold saving in cost.

It is a further and more particular object of the invention to provide an apparatus which is extremely simple in operation; is capable of being operated at relatively low cost; and by which a continuous stream of finely divided mineral or ore is produced in which the particle sizes. are substantially the same.

More particular and specific objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the in vention may be employed.

In said annexed drawing:

Fig. l is a plan view of one form of apparatus embodying the principles of my invention and by which the process of my invention may be performed;

Fig. 2 is a vertical section through the apparatus illustrated in Fig. 1 taken on a plane substantially indicated by the line 22; and

Fig. 3 is a fragmentary sectional view of one portion of the apparatus as illustrated in Fig. 2, but illustrating an alternative form of construction.

Broadly stated, the apparatus of my invention may be described as comprising in combination A classifier cell, 7

Means for collecting and conveying to a point above the liquid level in such cell the material which settles in such cell,

A pair of grinding rolls mounted over said cell,

Means for projecting such collected material into said grinding rolls, and

Said rolls arranged so that the ground material delivered thereby is projected into that portion of said cell wherein classification occurs.

Broadly stated, the method or process of my invention by which a continuous stream of uniformly sized particles of mineral substances such as ore may be produced comprises Passing the work through crushing means,

Delivering the work from said crushing means to a classification cell,

Collecting that portion of the work which settles in such cell,

, 2,762,574 Patented Sept. 11, 1956 By having reference to the drawing and more especially to Figs. 1 and 2, it will be noted that the apparatus here illustrated comprises essentially a classification cell generally indicated at 1, means positioned over the cell generally indicated at 2 for the purpose of feeding to the cell the stream of material to be classified; a collecting conveyor 3 located in the bottom of the cell for the purpose of collecting the portion of the material which settles in the classification cell; means generally indicated at 4 by which the collected material carried upwardly by the conveyor 3 is projected into the feed side of a pair of regrinding rolls 5 which deliver the reground material into the classification area in the cell.

Referring now more particularly to the classification cell 1, it will be observed that it is an elongated cell having end walls 6 and 7', and side walls 8 and 9. The bottom 10 of the cell is inclined upwardly from the wall 6 which is provided with a discharge weir 7.

The depth of the liquid in the cell is of course deter? mined by the height of the weir 7. The incoming stream of material to be conditioned by the method and apparatus of my invention is subjected to a grinding operation which may be performed by a series of grinding rolls generally indicated at 11. 1 I

The grinding rolls 11 deliver the material downwardly to a trough 12 which extends across and is supported on the classification cell which trough is of such length and width as to intercept fully the stream of raw material issuing from the bottom grinding rolls 11.

Extending into the trough 12 are conduits 13 and 14 arranged to deliver to the trough streams of water in such quantity as to wash the ground material intercepted by the trough through conduits 15 and 16 which lead from the opposite ends of the trough 12 downwardly and into the sides 8 and 9 of the cell at a point well below the liquid level therein and at a point a substantial distance from the weir 7.

The material discharged into the classification cell through the conduits 15 and 16 divides into two parts. The first part which is of sulficient fineness to be carried upwardly by the water flowing out of the cell over the weir 7 is finished product and the other part which settles in the cell requires further processing. That portion of the material which settles in the classification cell falls onto the upper run 17 of the conveyor belt 3 which is trained about pulleys 18 and 19. The conveyor belt is driven in the direction indicated by the arrows so that the material which settlesthereon is carried out of the bath in the classification cell at the end remote from the weir 7.

Carried by a suitable support on the structure of the classification cell is a scraper blade 20 which rests on the conveyor belt 3 to scrape therefrom the settle material carried out of the bath.

Rotatably supported by means of suitable brackets likewise on the structure of the classification cell, is a cylindrical brush generally indicated at 21 which rotates in substantial contact with the scraper blade 20 and by which the material collected on the latter from the belt 17 is projected in a trajectory generally indicated at 22 into the bite of a pair of grinding rolls generally indicated at 23 which are preferably driven by means not shown at a peripheral speed substantially greater than the speed at which the material to be reground reaches the rolls.

The material after passing through the regrinding rolls 23 is projected in a trajectory generally indicated at 24 so as to fall into the bath in the classification cell in the area at which the stream of water enters the cell through the conduits 1'5 and 16.

While ordinarily a rubber or similar type of endless conveyor belt 17 will beernployed a'nd thuswne'Cessitating ethe use of a scraper blade such :as -20finor.der to;prevent direct contact between the brushl-Zl -and-the belt 17 so as to prevent undue wear, nevertheless, for certain types of material from which the brush and 'belt'may be formed it may be possible 't'odisp'ens'e with "the scraper blade as indicatedin Fig. 3 and have the brush"21pick upthematerial directly "from 'thebelt and project itinto the rolls23.

From the "foregoing description, it 'will 'be' observed that I"have providedan extremelysimple form of apparatus by 'which a continuous stream of mineral material may be converted toa'continuousstream of finelydivided particles thereof, all of substantially the same "size 'and this 'is accomplished'without the use of expensive ball mills or allied types 'o'f'apparatus heretofore used for the same purpose. V j

Gth'er modesof applying the principle of the invention may be'employed, change=being made as regards'the-details described, provided the features stated in any ofthe following claims or theequivalentof such be-employed.

I therefore particularly point out and distinctly claim as "my invention:

'1. In apparatus of the character described, in combination: a classifier cell whereinsolid material is'classified-in a risingstreamofliquid, means for collecting-and conveyin'gto a point above the liquid level in -such=cell the material which settles in such cell a pair of grinding rolls mounted over said cell, means for projecting such collected material into said grinding rolls,'and said rolls arranged so that the ground material delivered "thereby is projected laterally into thatportion of'said 'cell wherein classification occurs.

2. In apparatus ofthecha'racter described, in combination: a classifier cell wherein-solid material is classified in arisingstrearn of liquid 'having a discharge weir at the top of one -end wallthereof, means for introducing in a stream of liquid the material ito be classified into such cell "below the normal liquid level therein, means for collectingand conveyingto a;point abovethe 'liquid level in such cell the material which settles in such cell,":a"pair -of grinding rolls mounted overisuch cell, and means for projecting such collected materialiintosaidgrinding rolls,

said rolls arranged sothatthe ground material delivered thereby .isrprojected laterally into that portion of'said cell wherein classification occurs.

3. In apparatus-of the charac'terdescribed, in combination: a classifier cell wherein solid material is classified in a rising stream of liquid, having a discharge weir at the top of one end wall 1there'o'f,:conduits leading into the opposite sides of said cell below thenormal liquid level therein, liquid supply means connected to such conduits, means for introducing'the material to be classified into such conduits, an endless web having a material intercepting and conveying section extending I-in an inclined path insaid cell from below the liquid level adjacent said weir to above the liquid levelat the opposite side of said cell, a set of grinding rolls above said cell, means for projecting the work material carried above the liquid level by said web into said grinding rolls, and said grinding rolls arranged so that the plane through the axes of said cells intersects the normalliquid surface in such cell at an oblique angle thereto.

4. In apparatus of the character described, in combination: a classifier cell wherein solid material is classified in a rising stream of liquid, having a discharge weir at the top of one wall thereof, grinding rolls mounted above said cell, a material collecting trough over said cell under said rolls, a conduit leading from said trough into said cell below the normal liquid level therein, water supply means forsaid trough whereby the material delivered thereto by said rolls is carried through said conduit into saidcell, an endless conveyor having a material collecting section extending in an inclined path from below the liquid leveladjacent said'weirto above the liquid level at the opposite side of said cell, a second set of grinding rolls above said cell, means for collecting the work material carried above the liquid level by said endless conveyor, means for ,projecting suchcollected mate rialinto said second set of grinding rolls, .andsaidsecond set of grinding rolls arranged to project the material ground thereby into the classification area of said cell.

5. Apparatus as described in claim 4 characterized furtherin that said grinding rolls are provided with means driving the same at a peripheral speed greater than the speed of travel of the material 'fed thereto.

'6. Apparatus as described in claim '4 characterized further in that said projecting means comprises a cylindrical brush mounted for rotation about an axis parallel to the axes of said grinding rolls.

7. In apparatus of the character described, in combination: a'classifier cell wherein solid material is classified in a rising stream of liquid, having a discharge weir at the top of one wall thereof, grinding rolls mounted above said cell, a material collecting trough over said cell undersaid rolls,conduitsleading from opposite sides of said trough into the opposite sides of said cell below the normal liquid level therein, water supply means for said trough whereby the material delivered thereto by said rolls is carriedthroughsaid conduits into said cell, an endless web having a material supporting section extending in an inclined path "from below the liquid level adjacent said weir to above'the -liquid level atthe opposite side of said cell, a second set of grinding rolls above said cell, means for collecting the work'matenal carried above the liquid level by said web, means for projecting such collected *materialinto saidsecond set of grinding rolls,

and said second set of grinding rollsarranged to project the material ground therebyinto theclassification area of saidcell.

References Cited in the file of thispatent

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