US1889989A - Method of separating borax - Google Patents

Description

Dec. 6, 1932. R. HUGHES METHOD OF SEPARATING BORAX 3 Sheets-Sheet l www 8x.

INVNTOR Dec. s, 1932.

JT R. HUGHES METHOD OF SEPARTING BORAX Filed May 9. 1930 3 Sheets-Sheet 2 INVENTO'R A? JoHN`R|LEY HUGHES Dec. 6, 1932. J, R; HUGHES 1,889,989-l METHOD OF SEPARATING BORAX Filed May 9. 1930 5 Sheets-Sheet 3 o n o .Tom a IIN Nw a a o a u a o o o o o n M u @be a D n Ir hwl.-

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Patented Dec. 6, 1932 UNITED STATES PATENT OFFICE JOHN lEdif-EY HUGHES, OFcLYNWOOD, CALIFORNIA, ASSIGNOB T0 VICTOR C. EMDEN,

0F LOS ANGELES, CALIFORNIA 'METHOD' OF SEPARATING BORAX Application led Hay 9, 1930. Serial No. 451,100.

Thisjnvention relates to the art of separatingffrom eachother relatively hard and soft components of a mass of comminuted material, and an object is to eect such separation in a thorough, simple, cheap and effective manner.

'Ifhere occur in nature, deposits made up of mixtures containing materials chemically differing from each other in their capabilities for use, and physically distinct from each other in structure and in their degrees of friability; and I have discovered andinvented noval provision for rapid and satisfactory separation between components of masses of such material according to structural form and relative hardness.

i yI have discovered-that with some materials found naturally together as ores in place, or in the form of loose mixtures, ready separation can be had by subjecting the mass made up of such mixtures to a reducing process by which the softer or more friable components of the nass will be brought to sizes smaller than the less friable components, andthe two substances delivered practically free from each other.

I shall describe the novel discovery as applied through the means of a novel concenf trator screen embodying myi invention.

This discovery and invention relates primarily to the separation of shale from sodium bor-ate in material found and now being mined near Kramer, California; and-in practice I first crush the ore or raw mineral taken from thel mine and calcine the same by passing thepulp in aywell known manner, through' a calciner, subjecting the mass of crushed shale and borax to such degree of heat that the borax loses its water of crystallization and becomes much softer than it was on entering the calciner as borax crystals, and the shale is `made harder than it was on entering the calciner, so that the differences between the two substances are accentuated.

The lumps or ,pieces of raw material charged into-the calciner are measurably disintegrated by the treatment in the calciner, and the shale appears in scales or flakes, while the borax somewhat resembles popped popcorn, both in appearance and hardness; and

I have discovered that it is possible to so op- I erate upon the mass that the dehydrated borax is worn down by the operation, while the shale remains practically in the same forms and sizes as when the charge was removed from the calciner; and that by subjecting the calcined mixture to successive grindings effccted in the presence of, and by attrition of soft yielding grinding mediums, the borax may be so reduced that it will pass through screening means as a ground product, while the shale passes such screening means and may he discharged as rejects or'waste while the borax is discharged as a valuable product. I have provided a screen barrel having a peripheral screen wall, the mesh of which is of different sizes so as to allow escape of the borax in different sizes at different stations; and I provide means whereby separations of the different sizes of borax may be made as the disintegrated material moves along inside the screen barrel, and I provide partitions inside such barrel to form separate compartments within which the material may be successively ground with an action that reduces the size of the brax without changing the sizes or shapes of the shale, provision being made by appropriate arrangements of screens to permit escape of borax as it is reduced to sizes less than the crushed shale.

The screen walls of the periphery of the barrel are of different meshes at different zones along the barrel; and the mesh 4sizes A for the successive pockets is made to correspond to the sizes to which the borax ground beforeentering the calciner, and to the fineness to which the shalehas been reduced before reaching the screen barrel.

An advantage gained by this invention and discovery resides in the cheapness, ease and certainty of obtainingpure sodium borate from the mixed product of said deposits.

I have provided baies that have holes through which the pieces of shale in the broken ore can pass from end to end of the inner screen so that while the screen rotates, the shale may pass on while the borax is worn down and falls .through screen meshes over which lthe shale scales or akes will slide 011 toward a place of waste discharge.

An object is to so construct the apcparatus that se aration of the soft and har materials o a given quantity of mixture can be the barrel.

Other objects, advantages and features of the discovery and invention may appear from the drawings, the subjoined detailed descrip- `tion and the appended claim.

The discovery and invention may be understood from the following description by reference to the accompanying drawings.

Figure 1 is an elevation mainly in longitudinal mid-section, of apparatus constructed in accordance with this invention and adapted for use in carrying out screening operationsl of the method involved in my discovery; the barrel and other parts are shown in section on line w1, Figs. 8 and 9, and the shaft and screw of one of the discharge conveyers is shown intact, diagrammatically.

Fig. 2 is a face view of an assembly of the four segments of the first or primary baiile, showing such segments in the positions they occupy relative to each other when on the shaft in the screen drum.

Fig. 3 is a face view of oneof the segments of the primary baille, separate from the other segments.

Fig. 4 is a view of the second baie correspending to the primary baiile except that it has smaller ports.

Fig.'5 is an outside edge view of a primary baie se ent with bolts in place.

Flg. 6 is a face .view of a primary baie segment with bolts in place.

Fig. 7 is an outside edge view of a seconday batlie segment detached, with bolts in place. Fig. 8 is a transverse section of the screening apparatus on line w8, Fig. 1, in a scale larger than that of Figs.'17. l

Fig. 9 is a transverse section on line m9, Fig. 1, inthe same scale as Fig. 8.

ig. 10 is a diagrammatic elevation of the housing viewed at the longitudinal vertical mid-plane thereof, indicated at line w10, Fig. 11, omitting the screening and conveying apparatus and showing one of the guideways on which the adjustable transverse partitions are slidably mounted.

Fig. 11 is a. cross-sectional elevation of the housing and one of the slidable partitions hung therein.

Fig. 12 is an elevation of the movable partition, a frame section and the slideways on which the frame section is mounted.

Fig. 13 is an edge view of the frame section shown in Fig. 12.

Fig. 10, 11, 12 and 13 are in the scale of Figs. 1-7 and 10.

wing to the small scale of the drawings no attempt has been made to show the various screens; but splotches of various mesh have been shown in Fig. 1 to indicate the change from liner to coarser and to also indicate the lines where two screens of different size mesh, meet.

The screening and soft grinding concentrating apparatus shown in the drawings is intended to operate upon material that has been crushed to sizes that will pass through a three-quarter inch round opening and such crushed material is calcined before entering the screen which is cylindrical and is made up of a barrel composed of screen sections and grinding compartments. tained in a housing 1 in which the barrel 2 revolves, and said housing is closed around Said barrel is conthe barrel, except at a feed opening 3 at the head, and outlets at the bottom for gravity` discharge of the separations into two parallel longitudinal conveyer troughs 4 and 4', in which there are separate conveyers shown as screws 5 and 5', by which the borax and shale are discharged separately at the tail of the machine. Y

The side walls 6 and 6- of the housing are inclined downwardly and inwardly to discharge the screened material into the conveyer troughs.

The proportions of the apparatus parts may be given as follows, it being understood that the apparatus may be made in various sizes and that appropriate dimensions according to size of apparatus may be determined by the constructor.

The inner screen drum 7 in the apparatus `shown, may be 48 inches in diameter, and such drum is shown provided with an annular dished head 8 into the intake 9 of which a spout 10 is led through the opening 3 of the housing to discharge the ground calcined material into the inner screen drum. Said inner screen drum is made up of screen sections as follows: The first or initial inner screen section 11 is 60 mesh and is three feet long. The second inner screen section 12 is ilo 50 -mesh and three feet long. The third inner screen section 13 is 40 mesh and three feet long. The fourth inner screen section 14 is 30 mesh and only thirty inches long. The fifth inner screen section 15 is 20 mesh and only 'thirty inches long. The sixth inner screen section 16 is' 10 mesh and thirty lnches long.

It is understood that the diameters and lengths of the screen sections may be varied without departing fromwthe spirit of the 1nvention, the principle of which in this respect is that material` passin along the -inner screen barrel will be disc arged from screen to screen in successively increasing larger and larger sizes from 50 mesh to 10 mesh.

The outer screen is made up of separate jackets 17, 18 and 19, which are respectively fixed to imperforate hoops 20, 20', 21, 21', 22, 22', and secured by bolts 23 and spacers 24 to four longitudinal ribs 25 formed of angle irons inside the inner screen of drum 7 said bolts 23 passing through the inner screen and the flanges of the ribs so as to unite the inner screens and the outer screens to each other to form a revolving unit which is mounted on a central shaft 26.

The hoops andthe ribs go to make up the frame of the inner screenA drum or barrel.

The irst or head outer screen jacket 17, surrounds the head portion of the inner screen and is made up of a section 27, of 65 mesh screen three feet long, and a section 28, of 60 mesh screen eighteen inches long, electrically welded to and forming a continuation of the first outer screen section; so that said rst jacket is fifty four inches long.

The second outer screen jacket 18 is made up of a 55 mesh screen section 29 that is three feet long and a 50 mesh screen section that is eighteen inches long and is electrically welded to andforms a continuation of the screen section 29, so that the second outer screen jacket is also fty four inches long.

The third outer screen jacket 19 is made up o a 45 mesh screen section 31, that is three :feet long, and a mesh screensection 32, that is twelve inches long, welded to the section 31.

The two outer screen jackets 17 and 18 are thus 54 inches long, respectively, and the third outer screen jacket 19 is 48 inches long. The jackets 17 and 18 are separated at their ends by a discard or rejects channel or space 33, and the jackets 18 and 19 are separated at their ends by a discharge channel or space 34`.

The jacket 17 discharges waste into the discard channel or space 33, the jacket 18 discharges waste into the space 34, and the jacket 19 discharges waste into a discard channel or space 35; each of said jackets being. open to discharge at its end that is op posite to the head of the screen drum. Pairs of baiiies 36 and 37, 38 and 39, 40 and 4l,A

form partitions inside the inner screen, and the members of each pair are spaced apart as at 42, 43, and 44, to form .grinding chambers which are provided with linings 45, 46, 47, extending across the chutes 33, 34, 35, that open down into the conveyer troughs through outlets 48, 48', 48".

The grinding chambers are formed of open ended cylindrical one-eighth inch steel shells having at their ends, one-eighth inch thick annular heads 46'.

Said linings may be made of any suitable material, preerably such as rubber-covered belting crimped inside the frame composed of the hoop and the longitudinal ribs 25 so that the linings form soft longitudinally corrugated or luted walls for the grinding chambers respectively. Inside of such grinding chambers there are provided soft grindingr balls 49 of material such for instance as hard rubber so that they are notof such weight land hardness as to crush the shale, but are of suflicient weight and hardness to grind the lumps of calcined borax. Such balls will remain operative so long as they are of suiicient size to be retained by the perforated baiiles.

The bailies 36 are provided with ports 50 of suflicient diameter to allow the passage therethrough loi all the coarser material deposited in the irst screen chamber 51 so that all that will escape from the irst screen chamber 51 through the 60 mesh inner screen section 12 to the 65 mesh outer screen section will be of 60 mesh or less ineness, and alll of the fines that'pass through the'first outer screen jacket 17 Will be of 65 mesh 0r less size; and whatever material delivered to the 65 mesh screen, is of greatersize than 65 mesh, will be discharged through the interjacket discard space 33.

Movable imperforate transverse partitions 52 and 53 respectively separate the housing y l space below the jacket sections 17 and 18 into two compartments 54 and 55 which are lopen through passages 56 and 57 respectively, into the conveyer troughs; and the openings are respectivelycontrolled by gates 58 and 59 that are shown as slides each having an opening 60 adapted to allow discharge into either of the troughs with whichthe opening 1s allowed to register. Each gate is connected ,by a link 61 with a hand lever 62 pivoted at 63 and operating in a segment 64 and held stationary in adjusted position by anyl suitable means as the pin 65 inserted through the lever and the segment at the appropriate ad,

justed positions; there being a hand lever and 'gate for each opening.

The partitions 52 are adjustably fastened to the housing by laterally extending bolts 52a that extend through slots 5212 in the walls of the housing; and when it is desired to shift any partition along the Ahousing to change the plane of separation between the fines and the coarse, the bolts may be loosened from outside the housing and the partitions shifted accordingly.

Other partitions as at 52', 53', are likewise provided where itmay be desirable to make separations at different cross planes of the housing, and it is understood that if the constructor so desires, he may apply or omit the adjustable feature of the partitions as may be determined to suit the conditions of the ore at any locality.

It is also understood that other features of' invention.

66 indicates hubs slideable on the shaft 26 and provided with flanges 67 adapted to receive the threaded ends of the cap screws or bolts 68-that are rovided for the purpose of securing the per orated baffle plates to such flange hubs; and the peripheries of the baille plates are recessed to lit upon thelongitudinal angle ribs so that when the baille plates are lixed to the anged hubs, the bales with their hubs may be slipped along the angle yribs inside the inner screen, thus to chan e the spaces through which the lines may be discharged from the inner screens into the outer screen jackets without disturbing the relation of the outer screen jackets to the discard spaces 33, 34 and 35; and if in the practical working of the apparatus it is found that greater or less space may be given to dis'- charge from the inner screen to -the outer screen jacket, the grinding chamber or com' partment 42, 43 or 44 may be shifted accordingly. j

For convenience of construction, the baiiles are segmental andthe joining edges of the segments 69 are notched at the peripheries .of the se ments as at 70 and 71; and the joining e ges are notched with half holes 72 to accommodate the bolts 681.

The hubs 66 are provided with channeled spokes 73 in which are' fitted sp'oke'extensions 74 into which the bolts 68 are screwed to holdthe segments in position on the hubs.

The partitions as at 52, 53 and 53 are supported by longitudinal rails 75 which may be lengths ofpipe secured to the frame 76 of the housing. -Said partitions are preferably of sheet metal notched to accommodate the rails 75 and to allow the partitions to be shifted alonginside the housing. Said housing may be made of metal plates indicated at 7 7 and 78, secured by rivets as at 79 to each other and to frame pieces 80 that may be angle irons. The shaft 26 may be supported by any suitable form of bearings, not shown, in the ends 81 and 82 of the housing.

The lining for the grinding compartments vis preferably made of a good grade of heavy rubber conveyer belting or may be of any other soft resilient material that will with stand the wear; and the same is rolled inside the frame of the inner screen, is passed over the four longitudinal angles 25, and is held on the back by one-eighth inch blank steel plates 83, both of which are vof the same diameter as the inner'screen section, and placed between the ends of the first and second screen sections. Inside this compartment, and rollinto the third grinding The part of the housing below the revolving screen bars forms ore pockets 54, 55, a,

555, 550, 55d, 55e, 55 and 55g, into whichl will fall all the line y round or rounded material that asses t rough the outer screens, and the discards discharged from the ends of the outer screen sections 17, 18 and 19 are delivered to the discard chutes 33, 34, 35. The final discards from the inner'screen barrel reach the final discard chute 84.

The calcined and crushed ore enters the apparatus at the upper, or left hand endas viewed in Fig. 1; and is delivered through the annnular dished head, the opening of which is sufficiently large to accommodate the shaft and the spout for delivering the ore inside the inner screen. After enteringthe inner screen, mesh nes of values and of waste, may pass throughthe 60 mesh section of the inner screen and into the cylindrical mesh .outer screen or jacket, and the over size material inside the 60 mesh* screenof the inner screen section passes out of such inner screen through the holes in the baille plate and into the first grinding compartment 42`and becomes subject to the grinding operation of the soft grinding medium af.-

forded by fthe balls and the lining.

The soft grinding thus effected reduces the size of the calcined sodium borate lumps, and the ore containing the reduced lumps and the scales of shale, will gradually pass through the holes of the second baille plate and on to the 50 mesh inner screen section'. Here all material finer than 50 mesh, passesthrough the inner -50 mesh screen and on to the inner side of the outer screen or-jacket. All the material larger than 50 mesh and remaining' on the inner screen, passes through the holes.

in the next baille .plate and into the secondl grinding chamber. Here the operation described with respect to the first grinding chamber is v repeated and the ore passes throughthe next baie plate and on through the 40 mesh inner screen. Here all material l screen or jacket. All material larger than 40 mesh passes through the next baille plate and chamber. This -grinding chamber is made shorter than the preceding irst and second grinding cham-v bers because the amount of material remaining in the inner screen will be greatly reduced by the time it reaches the third grinding chamber. The grinding operation in the third grinding chamber will correspond to that described -for the preceding grinding chambers, and the o re passes through the next baffle plate on to the 30 mesh inner screen section, and all the material ner than 30 mesh will pass throu h the 30 mesh inner screen into the ore poc et beneath.

All material larger than 30 mesh will pass on to the next 20 mesh inner screen section; and all material liner than 20 mesh will pass through the 20 mesh screen section into the ore pocket below; thence all material larger than 20 mesh will pass on to the last l0 mesh screen section and all material finer than l0 mesh will pass through the-10 mesh screen into the ore pocket below. All material larger than l0 mesh will pass over the end of the l0 mesh screen and into a waste pocket.

Meanwhile, the ore thathas passed from the 60 mesh inner screen to the 65 mesh outer screen is separated as follows. All material liner than 65 mesh passes through the outer screen jacket into the first ore pocket and thence to the ore discharging conveyer screw.

All material larger than the 65 mesh passes on into the continuation of the outer screen and is discharged into the lower pocket 58 below the 60 mesh screen and all material that is larger than 60 mesh passes over the end of the 60 mesh screen and into the waste pocket below.

It might be assumed that because all the material handled on the 65 and 60 mesh outer screens has passed through a 6() meshrinncr screen that all of such material that might be passed through the 60 mesh outer screen, would have passed through such screen, but experience has proved that this is not always the case.

By the time the material reaches the 60 mesh section of the outer screen, the borax has been greatly reduced and the small pieces of shale which are always ilat, or at least have one ilat side, have a tendency to slide over the mesh of the screen and olfv over the end into thewaste pocket or chute. While the material was on the 60 mesh screen there may have been suilicient material and Weight in the mass to force the small fine pieces of shale through the 60 mesh inner screen; and, by reason of the reduction of Weight such fiat pieces of shale so found may pam over the 60 mesh inner screen and be discharged at the end thereof as waste. For this reason,

frequent discharge of waste is provided so that as small an amount of shale as possible is carried along, and the separating. screens are set' in appropriate lengths to avoid the necessity of grinding all the borax to the fine size. By the time Vthe mass has passed the third grinding, the smaller pieces of shale will have been disposed of, and what is left will readily slide over the coarser mesh screens through which the rounded pieces of borax readily pass.

Therefore, the material on the last four sections of the outer. screen or packet is handled in the same way as that on the lirst two sections. Although the mesh of the screen sections is enlarged in each instance, the pieces of liat face shale, though being tine enough under a certain pressure \to pass through the larger mesh screen, will not pass through the coarser mesh screen under a like, or a less pressure, when the amount of material has been soy reduced, as indicated, that the pressure thereof is not suiiicient to force the fiat sided pieces through such coarser screen.

The operation as the material passes along in the last four sections of the outer screen or jacket is analogous to that just described.

1f, during operation, it is found that too much shale is passing through the second or 6() mesh outer screen up to or at any point of advance, the partition blank may be moved to such point as will cause such material to pass out `through the waste pocket next below such partition, and at an earlier stage of travel.

One of the two screw conveyers is for the soft ore and the other is for the waste; and the slides are so controlled bythe operator that the opening in the slide is either over the waste conveyer or over the ore conveyer as terial in any pocket is'too high in shale to be called ore, the hole in the slide or gate can be brought into position over the waste conveyer for immediate discharge.

lf any part of the material which passes through the second, fourth and sixth sections of the outer screens or jackets is ore or waste, whichever the case may be, then the partitions placed at the ends of these three screens or any of them, may be moved to the point or points Where the ore and waste will be properly separated.

The ,holes 50', in the baffles 36 are of less diameter than the holes 50 in the ballles 36, so that the soft lumps of material passing the first grinding chamber andinto the second grinding chamber will be retarded in such second chamber for finer grinding, and so on, passing out of the grinding chambers as the lumps of borax becomes so reduced that they will pass too freely through the holes in the later bullies, care being taken that the holes are always large enough to allow the largest sizes of shale scales to pass. v

The grinding compartments or chambers 42, 43, 44, will be supplied with the relatively light grinding balls 49, as of hard rubber, capable of grinding the borax, but incapable screens and all of the borax, both coarse and ne, passes through the screens and is discharged apart from the shale.

I claim The method of obtaining borax from comminuted mass of ore containing a mixture of sodium borate and shale; which consists in calcining such mass, thus dehydrating and softening the sodium borate and producing a more friable borax, and hardening and making less friable, the shale; soft grinding the mixture, thereby reducing the borax in size and shape without like reduction of the shale, and causing separation between the borax and ,shale according to the differences of the twom'aterials with respect to size and shape.

In testimony whereof, I have hereunto set my hand at J eerson City, Missouri, this 29th day of April 1930. f

JOHN RILEY HUGHES.

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