US2164052A - Disintegration of matrix, mud balls, etc. - Google Patents

Description

J1me 9 J. T. BULLWINKEL 2,164,052

DISINTEGRATION OF MATRIX, MUD BALLS. ETC

4 Filed Aug. 16, 1935 3 Sheets-Sheet 1 Fi .2.. /Z /0 INVIIINTOR ATTORNEYS June 27, 1939.

J. T. BULLWIN KEL Filed Aug. '16, 1935 11/076 tonfall i/l ig Pfiapbafe Mfr/LY Jqaorafor 4 screen n Ores/2e, l

DISINTEGRATION OF MATRIX, MUD BALLS, ETC

ISShoots-She-t 2 Je mfa Bedrock N 73M WNTOR ATTORN EYS June 27, 1939- J. T. BULLWINKEL Filed Adg. 16, 1935 DISINTEGRATION 0F MATRIX, MUD BALLS, arc- 3 Sheets-Sheei 3 ATTORN EYS go .the softer materials Patented June27, 1939 UNITED STATES PATENT OFIFICE;

nrsm'meaarron 1;

John 'rmiaweu Bullwinkel, Brooklyn, n. Y. Application August 16, 1935,-Serial No. 36,472

' 2 Claims. (01. 209-6) This invention relates to the treatment and disintegration of softer materials, such as agglomerated clay, so-called clay balls or mud balls, etc., admixed with; harder materials. More particularly the invention relates to the treatment or disintegration of phosphate matrix, containing pebble phosphate embedded in or intermixedwith sand and clay, so that the pebble phosphate can be readily separated and recovered. The inno vention includes both an improved method of treatment or disintegration and improved apparatus therefor. a

The invention, in its broader aspects, is applicable to the disintegration of various materials,

16 containing harder and softeringredients which,-

it is desired-to separate from each yother, and where so-called logs and scrubbers are now commonly usedior bringing about such disintegration of the "softer materials, and the washing of grated harder materials. The improved process and apparatus of the inention are, however, of particular value in coni nection with the disintegration of phosphate matrix and'similar materials, and will be more particularly described in connection therewith.

Phosphate matrix consists principally of phosphate in the form of pebbles ranging from minute sizes to pebbleslarger than one inch'in size. but

go for .the most part of pebbles less than one-half 40 matrix, a loosening or separating by water of the phosphate pebbiesirom the clay and sandso that v the'disintegrated material can be screened and washed and the pebble phosphate recovered therefrom.

The disintegration or phosphate matrix a an 7 imp rtant and necessary step preliminary-to the washing and screening treatment because it otherwise isquite impracticable impossible to recover a marketable product by washing and so screening.

- Phosphate variesconsiderably. A ma trixcontaining a high percentage of sand disintegratesm'ore easily than amatrix containinga high percentageoi clay. In some conditions ma- Ie'trix'isiound which stifljfiand diihcnlt away from the undisinteing and disintegrated by the use of to disintegrate. Such stifl matrix, diflieult to disintegrate, causes the greatest trouble in wash ing and screening, because the lumps 01' balls of matrix, frequently called mud balls, will remain in the washing proces's'to the end and thus contaminate and lower the quality of the'flnished phosphate product. To avoid this contamination of the product, the larger lumps 01' matrix containing phosphate, and also pebbles of phosphate of the same size or larger,- are usually thrown 10 away as debris. The smaller lumps or mud balls are usually subjected to'some sort of a scrubbing treatment. such as with legs or scrubbers, etc., to

eiIect the necessary disintegrating action. 'It is important to disintegrate all mud balls thori5 oughly and as quickly as possible because under some conditions they will pick up rock and other mud balls and then become more troublesome.

, One method of disintegration of phosphate ma- 'trix which has been practiced for manyyears is m the hydraulic process in which the disintegration is-accomplishe'cl during-the mining, of the matrix with hydraulic guns, using pressures of around 200 pounds. lftis common practice in'hydraulic mining oi matrix, tore'iect at the beginning 01' the washing process, the larger niudbails by the use of separators which are usually the first 'units of the washing process. This rejection of the larger mud balls, etc., to debris, causes a loss of the phosphate which the mud balls'contain.

Another method of disintegrating the phosphate matrix is that described in my prior Pat-- ent-No; 1,901,231, granted -March 14', 1933, in which the phosphate matrix is mined by dry min- 1 In such process, after the matrix been disin tegrated by soaking 'and'sou'ping in the soaking pit, the largerlumps or mud balls are rejected from the washing process, by the use-of separators, and returned againto thelsoakin'g' pit. This 0 requires a rehandling of this partoiv the matrix, with consequent additional costL-L'I'hese-larger mud balls are usually 01' the stiflest and most dimcultklnd oi matrix to disintegratend they.

.may require,.theretore; rehandling a number of 4s times before they have been sum ciently'i'or'the washer tohandle.

With the mud balls whichhre' lost in the hydraulic. process. y lr i or debris, and with the oversize mud balls which are rehandled and recirculated in the dry mining process above referred to. there are some lumps of bed rock which, ii-permitted to enter into the phosphate product, will contaminate the product and lower its grade. ml! Q'ven with as airing pits. .35-

tionintofthewaste.

' or' the holes may be of other size and shape such satisfactory disintegration of the oversize mud balls, the phosphate product would be contaminated by such bed rock unless some means of eliminating the bed rock separately from the washing process is provided.

In the usual washing and screening operations, the logs and scrubbers used do not satisfactorily handle and disintegrate large mud balls or lumps of matrix, when the feed of mud balls or large lumps is a high percentage compared with the rock; and the logs and washers do not eliminate or reject the bed rock. I have found in some cases that when feeding mud balls to logs under certain conditions, the logs not only do not disintegrate the mud balls, but the clay gums up and chokes the logs. I have also found that sombbers, under some conditions, instead of disinte: grating the mud balls, merely reduce them somewhat in size. I have also found that both logs and scrubbers tend-to grind away the softer pebbles of phosphate while grinding away the clay balls, with resultant loss not only of tonnage of phosphate product recovered, but also a more serious loss'in grade and quality, since the softer phosphate pebbles, which are more easily ground away by mechanical handling, are usually the highest grade of phosphate.

The pebble phosphate rock, recovered from the phosphate matrix, as a result of the disintegrating, washing and screening treatments, etc., is

usually sold as 68% grade, 70% grade, 12% grade, grade, and 77% grade, and there are premiums in the selling price for each higher grade, and the highest qualities demand the highest premium. It will be noted from these grades that the matter ofone percent or two percent in quality is important and valuable, and therefore any loss in quality occasioned by unnecessary handling and treatment, or harsh treatment in the washing and screening of the pebble phosphate, is detrimental.

I have found that mud balls, which are difllcuit to treat by present methods, can be rapidly and effectively disintegrated by supplying them, to-

gether with water, to a distintegrator, hereinafter described, in which the mud balls or lumps oi matrix, while immersed in water, are subjected to the action of a submerged horizontal screen, which serves to support the material during its disintegration, and with rapid relative movement of the .material and screen during the disintegration.-

Thedisintegrator which I have found particularly effective is one with a rapidly rotatable horizontal screen carried by a vertical shaft and arranged within and/or near the bottom of a stationary cylinder which'is submerged in a tank or sump, and with the water level in the tank above the level of the screenand above the level of the material fed to the disintegrator, so that the material will be kept under water during its disintegration. Provision is made for feedingv the material to be disintegrated and also for feedin water to the cylinder-above the screen; and prothe screen.

'l'he rapidly rotatable perforated screenhas openings of suitable size for the particular material to be disintegrated. The holes may be circular holes of as much as one and one-quarter inches or one and one-half inches in diameter;

that the disintegrated material will pass therethrough'. The screen is arranged so that it can aromas be rapidly rotated, the rate of rotation varying somewhat with the diameter of the screen, and the quantity of material to be disintegrated.

I have found that the material can be disintegrated with the use of a stationary screen, instead of a rapidly rotatable soreen provided rapid relative movement of the material on the stationary screen is caused by rapidly rotating arms carried by suitable vertical shafts; but I have found the use of a rapidly rotatable screen mounted within and near the bottom of a stationary vertical cylinder, a particularly eifective arrangement of apparatus for accomplishing the desired disintegration of mud balls and phosphate matrix material.

The invention will be further described in connection with the accompanying drawings, but it will be understood that the invention is illustrated thereby but is not limited thereto.

In the accompanying drawings:

Fig. 1 shows one form of the disintegrator, in vertical section and with parts in elevation;

Fig. 2 is a top view of the apparatus of Fig. 1;

Fig. 3 is a flow sheet illustrating the treatment of phosphate matrix when hydraulic mining is used, with the disintegrating treatment of the present invention included in the flow sheet, and with the operations which are eliminated from the old process shown in dotted lines;

Fig. 4 is a flow sheet of the process in which dry mining of the phosphate matrix is employed, followed by the soaking of .the material, as described in my prior Patent No. 1,901,221, with the disintegrating treatment of the present invention included in the flow sheet; and with the portion of the flow sheet, when the present invention is not employed, shown in dotted lines; and

Fig. 5 is a flow sheet showing the application of the present invention to the disintegration of phosphate matrix mined by dry mining and without further preliminary disintegration before it is subjected to the present disintegrating process.

One form of disintegrator is illustrated in Figs.

metal, of a strength adequate to support the material undergoing disintegration. The cylinder is shown as imperforate, but it may be perforated near its lower end, where submerged, to permit dischargepf disintegrated material through the holes in the cylinder as well as'through the holes in.the screen. The mud balls or matrix to be disintegrated are supplied to the space inside the cylinder 3 through the feed pipes or feed chutes 1. Water is supplied to the space inside the cylinder I through the water supply pipe 0. A discharge plpe I. leads from the space in the tank I below the perforated screen through the centrifugal pump II by means of which the disintegrated material is withdrawn and pumped through the pipe II to the usual washing and screening machinery. The pump II is shown as driven by the electric motor l2.

Near the bottom of the cylinder-3 is an opening with a gateor closure l3 adapted to be raised by the operating rod II and handle '5. When the gate I8 is opened, the space inside the cylinder is connected with the pipe I. for discharging the bedrock to the debris sump or tank 2.

Inthe operation "of the apparatus, the water level is kept sufliciently high-so that the rotating screen and the material supported thereby are.

submergedland so that the disintegrationtakes 6 place while the material is so submerged. v

The rotating screen cau be rotated at varying and diiierent rates of speed or rotation. rate may be around 100 to 150 revolutions per minute for a screen around 3 or 4 feet in diaml eter; but the rate of-rctatlon can be varied aecording to the quantity of material to be disintegrated. In carrying out the process, with the apparatus'illustrated, the so-called mud balls'or clay l5' balls or other lumps of the matrix material to supported thereby,-inasmuch as the stationary cylindrical casing 3 tends to retard rotation of the water enclosed therein while rapidly rotating screen-tends to. cause the material supported thereon to rotate therewith. The result is an offective relative movement of the screen and of the material supported thereby, andan eiiectivc disintegration of the material.

When the material has been disintegrated to sizes smaller than the openings in the perforated screen, the disintegrated material 'falls through 1 the screen into the space in the tank below the .screen, and from there it is then pumped through 5 the pipe 9 and by means of the centrifugal pump Ill to a higher; elevation where it is'efed to the usual washing and screening units. Water is added 'to the disintegrator continuously for the purpose of providingwater for suspension of the 1 '40 clay separated from-the mud balls by the disintegrating treatment,;and for use 4n pumping away the material after it has beendisintegrated.

In thecontinuous operation of the process. there will be a continuous or intermittent feed/of the ssmud balls or other material to be disintegrated and a continuous supply of water, together with a continuous .withdrawal of the. disintegrated material from the space below the screen. As are suit, thereis adownwardmovement of the water in the cylinder 3, and downwardly through the perforated screen, so thatrelatlvely fresh water is in contact with the material above the screen, and the clay and sand, as they are separated from the mud ball, are carried in suspen-, ,65 sion in the water downwardly through the screen, and are pumped by the centrifugal pump to the subsequent steps of theprocess.

- The-mu d"balls may be admixed with bed rock.

' This bed rock, if permitted to remain in the phos- I phate product, will cause a lowering of the quality of the product. The bed rock which is much harder than the mud balls does not disintegrate in' the disintegrator except to a very limited extent', and therefore remains on the top of the 05 perforated rotating screen. Soft bed rock may be disintegrated and pass of! with the slimes. when sufliclent bed rock has accumulatedin. the disintegrator, which is easily determined. by the noise as it tumbles around,it can be easily discharged from the disintegrator by opening the gate 13 which permits the revolving screen to throw the bed rock out-of the disintegrator by centrifugal force. Thebed rock thus rejected is collected in the sump 2 which is shown as having the same to, level of ,water' therein ,as. in :the I tank cli er; that The there will not be any objectionable loss of disin tegrated material when the bed rock is discharged.

' When the bed rock is not present to an objectionable extent in the disintegratorQI have 5 found that it has a helpfulelfect upon the disintegration of themud balls. As the disintegrator can easily rejectthe bed rock, when it has accumulated to an objectionable extent, and as the bed rock is helpful in thedisintegration of 10 the mud balls, the bedrock'serves a useful function in promoting the disintegration, although its presence and action are not necessary to obtain the desired disintegration. F

The perforated rotatable screen may have strips .15 or bailles attached to its top to cause greater agitation of the material to .be disintegrated: but

' satisfactory disintegration can be obtained with a perforatedmetal plate. or screen without such added elements. r

The size of the .holes in the'screen will vary somewhat with the nature of the'material being treated. The holes should be large enough to 7 permit the pebbles of phosphate to pass there through. Ihave'found ascreen withone and g5 one-quarter inch circular holes'suitable for the treatment of mud balls; and screens with holes of oneand one-half inch diameter have also been used; as well as screens with holes rectanguin size.

I have found that the larger lumps of matrix,

mud balls and bed rock which are commonly dlscarded to waste in the hydraulic process of disintegration, can be treated in the apparatus and as in accordance with the process of the'present im vention with. consequent increase in recovery of phosphate and with elimination of .bed rock of.

larger than the openings used in the screen.

The flow sheet illustrated in Fig. 3 illustrates 40 the process, with the parts omitted in the 01d process shown in dotted lines. As illustrated in this flow sheet, thephosphate matrix in the mine is disintegrated with a hydraulic gun and the disintegrated material is pumped to a washerand. as then goes to a separator where the oversize and undersize materials are separated from each other. The undersize material goes in the usual washing and screening operation. The oversize materiaL'ofa size of'more than about one and so one-half inches, in the old process, is considered waste or debris and is discarded,- although it contains phosphate rock. a 3

According to the present invention this oversize material, made up of mud balls, bed rock, 156 'etc., and containing recoverable phosphate, is

subjected to the disintegrating treatment above described-and the separated phosphate,1etc.', is'

- then passed to theusual washing'and screening operations while the waste or bed rock, being so free from recoverable phosphate, forms the wasteor debris. 1

I have also found that in the dry mining process inwhich the matrix is disintegrated in water in soaking pits, as described in my prior Patent No. 95

1,901,221, the largeinud balls which are ordinarily separated out in the separators with four; inch openings, and returned to the soaking pit for resoaking and rehandling, can" be quickly, easily and more economically disintegrated by the dis-2,70;

integrator and disintegrating process of the present invention, thereby saving rehandling costs; and rejecting bed rock, and with a betterment of quality of the phosphate rock recovered. i ,1 The flow; sheetof Fig. 4 illustrates the applicalarin shape, one-quarter inch by one-half inch 30 tion of the present processand apparatus in connection with the dry mining of phosphate rock and the treatment of the material in the soaking pit; and, in this figure, the process is shown in dotted lines as it is carried out when the present When the present process is employed, this separation and return of mud balls for further soaking is eliminated, and the disintegrated mate- 'rial from the soaking pit is passed to a washer and then to a submerged screen separator of about three-eights inch size. The undersize goes to the usual washing and screening operations; while the oversize goes to the disintegrating treatment of the present invention and then to a separator where the remaining oversize, mostly coarse rock, goes to the debris pile, while the recovered phosphate goes to the usual washing and screening operations.

Ihave' also found that phosphate matrix which has been mined by the dry mining process, and which has not been disintegrated otherwise, can be satisfactorily and economically disintegrated by "feeding the dry matrix, together with water to the disintegrator oi the present invention, and by subjecting it to the disintegrating process of the present invention. Such dry mined matrix can be transported from the mines, and subjected to the present disintegrating process, without any preliminary treatment such as treatment in the soaking pit of my said prior Patent No. 1,901,221. when the matrix is thus directly treated, I have found that the side of the screen openings can be conveniently reduced to a size slightly larger than that of the largest pebbles to be required. Prodnets of diiferent sizes can be made with additional disintegrators, and by additional disintegrating treatments, according to the present invention, using appropriate sizes of openings of the screens.

The flow sheet of Fig. shows the small number of steps and operations involved in the preliminary handling and disintegration of the phosphate matrix. The matrix is mined by dry mining asby the use of a draglineor shovel, and is transferred by cars or otherwise, while in a dry undisintegrated state, and fed to the disintegrator; and subjected to the disintegrating treatment of the present invention. As a result, the matrix is thereby disintegrated to an extent such that it can pass advantageously through the usualwashing and screening operations; and these operations can be carried out in an advantageous manner with the material which is disintegrated 00 in this way.

The present process'and, apparatus are 'also,

applicable to the treatment of phosphate matrix, mud balls, etc., at various stages in the handling of the material, wherever mud balls are present, or wherever an effective and rapid disintegration of the matrix is desired. The use of the process enables practically the maximum recovery -of phosphate to be obtained, at low cost, and with high quality 'of products.

The disintegrating operation of the present invention should be distinguished from grinding operations of grinding rnachlnes, since the-action is accomplished by the rolling around of the materialon the. rotating screen, while submerged in water. As the material is retained on top of,

the screen until it has been suillciently disintegrated grator controls the necessary time element required for disintegration of clay, etc. in water.

Some matrix and some clays require longer time than others for disintegration, and the rotating to pass through the screen, the disinte-' screen holds back the material until it has had the necessary time required for its eflective disintegration.

The process and apparatus of the present invention present many advantages in the treat ment and handling of phosphate matrix, mud balls, etc., among them the following: A greater recovery of phosphate pebbles can be obtained from the phosphate matrix disintegrated by hydraulic mining by treatment of the mud balls which are normally rejected as debris or waste in such mining operations; a recovery of higher quality of pebble phosphate is obtainable by reducing the quantity of phosphate matrix in the form of mud balls that ordinarily would require treatment in logs or scrubbers; mud balls can be disintegrated in a more convenient and less costly way by eliminating the necessity of rehandling and recirculating mud balls one or more times; the bed rock contained in .or admixed with the mud balls can be separated and rejected while recovering the phosphate from the mud balls and balls of matrix with which the lumps of bed rock are associated; the disintegration by the present process is accomplished at reduced cost because the horse power required to operate the disintegrator of the present invention is very much less than the horse power required to operate either logs or scrubbers of equal capacity; the disintegrating action. ls less harsh than that of scrubbers and enables the recovery of greater quantities ,mined oversize product; or the rejection or recovery of a determined undersize product; or the rejection or recovery of both a determined undersize and a determined oversize product.

- The present invention makes possible the simpliflcation of the treatment of phosphate debris which is mined by dry mining operations. Where asoaking'pit treatment is used to disintegrate the matrix, the use of the present process enables the initial separators to be eliminated, as well as the cost of operating such separators. The present process moreover makes possible the elimination of the soaking pit treatment, by supplying the distintegrated dry matrix directly to the disintegrating process and apparatus of the present invention.

The process and apparatus of the present invention have the further advantage that, while the operation is a continuous one, the time element can nevertheless be controlled as required by diflerent materials, such as phosphate matrix and clay, for disintegration in water to a determined size. The-more easily disintegrated materials will be more readily disintegrated and removed while the more refractory and more difflcultly disiritegratable material will be given the necessary timeof contact to insure efiective dis- The invention has been more particularly dein connection with the treatment of now used. In general, the present invention makes possible the disintegrationof softer ma- .terials, such as clay, mud balls, clay balls, etc., in. aggregated form, from harder materials, by subjecting the aggregated clay or softer material, to combined mechanical action and the action of water under conditions which promote the dissipation of the aggregated soft knaterial into a flnely divided state such that it can be washed away from the harder and undisintegrated material. v I claim: 1. The method of disintegrating phosphate aggregates consisting of pebble phosphate having a covering of a softer material which comprises maintaining a relatively stationary mass of the aggregates at a substantial depth in a chamber having a surrounding stationary 'wall and enclosed withinan outer chamber, rotating against the bottom of said relatively stationary mass of aggregates a substantially flat horizontal screen having openings of a size to retain at least some of the aggregates but to pass at least some of the pebble phosphate after removal of the softer covering material, rotating said screen at a rate sumciently rapid to remove softer material from the retainet aamtes by attrition until they are of a size to'passthrough the screen. substantially continuously supplying aggregates and water above the screenfimaintaining said mass of aggregatw substantially submerged in water, and withdrawing from beneath the screen a water and material which passes through the screen.

2. The method of disintegrating phosphate aggregates consisting of pebble phosphate having' a covering of a softer material which comprises maintaining a relatively stationary mass of the aggregates at a substantial depth in a chamber having a surrounding'stationary wall and enclosed within an outer chambenrotating,

against the bottom of said relatively stationary mass of aggregates a substantially flat horizontal screen having openings of a size to retain at least some 01' the aggregates but to pass at least some of the pebble phosphate after removal of the softer covering material, rotating said screen at a rate sumcie'ntiy rapid to remove softer material'fromthe retained aggregates by attrition until they are of a size to pass through the screen,

I substantially continuously supplying aggregates and water "above the screen, maintaining said -mass of aggregates substantially submerged in water, withdrawing from beneath the screen water and material which through the screen, and withdrawing from the inner chamber above the screen material which is too large to pass through the JOHN msnwnr.

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