AU629965B2

AU629965B2 - Method and apparatus for mineral matter separation

Info

Publication number: AU629965B2
Application number: AU59964/90A
Authority: AU
Inventors: Rabinder S. Datta
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-07-30
Filing date: 1990-07-30
Publication date: 1992-10-15
Anticipated expiration: 2010-07-30
Also published as: AU5996490A

Description

i IIIIW~~ COMMONWEALTH OF AUS I2 9 9 PATENTS ACT 1952-69 COMPLETE SPECIFICATION

(ORIGINAL)

Class Int.

Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority SRelated Art Form Class Name of Applicant L Address of Applicant Actual Inventor Address for Service RABINDER S. DATTA 617 Tampico of America Court, Pittsburgh, Pennsylvania 15239, United States RABINDER S. DATTA WATERMARK PATENT TRADEMARK ATTORNEYS.

LOCKED BAG NO. 5, HAWTHORN, VICTORIA 3122, AUSTRALIA Complete Specification for the invention entitled: METHOD AND APPARATUS FOR MINERAL MATTER SEPARATION The following statement is a full description of this invention, including the best method of performing it known to us 1.

q_ 12 level is maintained in the vessel 12. This is accomplished by operation of the variable flow slurry pump Thus the degree of grinding and removal of matpr-il f-rnm :1 METHOD AND APPARATUS FOR MINERAL MATTER SEPARATION BACKGROUND OF THE INVENTION 1. Field of the Invention: The present invention relates to method and apparatus for accomplishing size reduction, classification, and separation of carbonaceous and noncarbonaceous mineral matter, and more particularly to method and apparatus for reducing the size of the mineral matter and separating the valuable constituent from the gangue.

2. Background Information: Over the past years substantial research has been conducted on the subject of utilizing domestic coal to provide a reliable, low-cost source of clean fuel. As a result of the research it 8; has been found that the major drawback to the use of coal as a o fuel is the mineral matter impurities present in it. It is o recognized that the development of a low-cost, highly benefi- 4 ciated clean coal will provide an attractive alternative for the energy market.

Know beneficiation processes generally concentrate or improve the physical and chemical properties of the raw material by removing a large fraction of the impurities present in the mineral. Mineral and ores, oil shale, °o copper ore and iron ore have also been beneficiated in order to produce feedstock for recovering the shale oil or extracting too the copper and iron. However, there is a need to enhance the efficiency of the size reduction and separation devices so as to produce the minerals and clean fuels at a cost and in a form that is economically attractive.

In conventional ball mills, the material to be ground is introduced into the mill at one end and the ground fine product is removed at the other end. The grinding media in the mill is alternatively stirred, vibrated, or tumbled to provide the energy necessary to grind/fracture the material to finer sizes.

A ball mill grinding apparatus as disclosed in Soviet Patent 594,294 includes a ported mixer paddle whereby water is 13 the rate of size reduction of the material to liberation size and thus change the proportion of the floatable and nonfloatable material in the system available for separation.

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supplied to the mixing chamber. The movement of the metal balls through the injected slurry serves to reduce the size of the material particles. Other similar patents, namely U.S.

Patents 3,149,789; 3,450,356; 3,226,044; and 3,486,705 disclose method and apparatus using liquid and grinding balls in combination with stirring paddles to process the injected solid matter.

In a conventional agglomeration beneficiation scheme, the material, such as coal, is comminuted to a predetermined average size such that the majority of the particles are liberated for separation. The coal in a water slurry is then introduced into a series of tanks and subjected to high and low shear agitation in the presence of the agglomerant. The agglomerated coal is separated from the refuse in the aqueous phase. The clean coal agglomerates may be subjected to a second separation step to separate the mineral matter which tend to get entrapped in the agglomerates.

s A known separator is a froth flotation cell where the hydrophobic particles e.g. clean coal, are separated from the hydrophilic particles, e.g. pyrite and other ash forming minerals. However, if the separation is not efficient the o, refuse may contain a high organic content or the clean coal mLay contain a higher than required mineral matter (ash) content. Consequently, in order to correct the problem one o or more of the following operations must be additionally performed: reduce the average particles size of feed, (2) comminute and reprocess the middling, or change the density of separation. Variations in the feed coal quality, as a result of changes in the in-seam coal quality, may result in higher than normal losses in organic recoveries if product quality is maintained.

A conventional gravity separation circuit uses heavy liquids, organic or inorganic, f-r achieving the separation of the coal and associated mineral matter. In the circuit, coal is reducted to a predetermined size and separated in a cyclone, using heavy liquids of a known density. If the middlings contain a high organic content which would result in low coal

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14 lower capital costs, reduced operating costs, reduced maintenance costs, reduced water requirements, reduced space requirements, and reduced energy requirements. Thus 1; recoveries, then they are reduced to a finer size and subjected to two or more heavy liquid separation stages to obtain a final product which meets grade and recovery specifications.

In a froth flotation cell, air is diffused into the slurry in the form of fine bubbles. Sufficient mixing is provided so as to enhance the probability of the hydrophobic particles striking and attaching themselves to an air bubble.

A relatively quiescent zone is provided so that the froth is formed and removed. In general the two main objectives are: to achieve a high recovery of the hydrophobic species into the froth product and to retain the maximum amount of the hydrophilic species in the slurry. The beneficiation of fine and ultrafine particulates a device is provided for the generation of extremely fine or microbubbles, resulting in S greater selectivity in the process, *j (The figure below diagrammatically illustrates a beneficiation circuit, utilizing the froth flotation separation process, consisting of various unit operations for the production of low-ash coal. The cumulative effect of inefficiencies in controlling and operating each of the several unit operations results in designing a larger circuit with reduced recoveries and leads to higher operating and capital costs.

o, Chemical Froth I Low-Ash Feed-- Grinding Condi- Flotation Lowtioning Sulfur Coal iddling Regrinding Chemical Froth Re- Conditioning Flotation ject Many efforts have been made to improve the beneficiation of coal and other materials by means of improving the froth ball charge in the separation zone or froth flotation section 34. Consequently, the movement of the ball charge in the grinding zone 40 is greater than the movement of the ball i; r 1 i flotation process. For example, U.S. Patent, 4,326,855 teaches a beneficiation process whereby "clean slurry" is ground and cavitated by sonic energy removing any contaminants including iron pyrites and ash.

U.S. Patent, 3,746,265 teaches a gravity beneficiation process whereby the source comminuted potash ore is subjected to gravity separation and subsequently subjected to froth flotation.U.S. 4,593,859 also discloses a gravity separation beneficiation process.

U.S. Patent, 4,564,369 teaches an apparatus whereby coal is pulverized and its surface is treated by contact with chemical reactants for ultimate removal of hydrophilic impurities.

U.S. Patents 4,597,858; 4,564,369; 4,597,857; and 4,593,859 disclose processes or methods for improvements of the benefication and/or separation of valuable material from its impurities.

Overall the known processes, such as sink and float separation, froth flotation, emerging selective agglomeration, and selective flocculation techniques require that the steps of size reduction of the material and the separation of its constituents be performed in separate chambers. Therefore, thre is a need for S a process whereby all the operations of size reduction, mineral classification and separation take place simultaneously in a single vessel in order to achieve higher separation efficiencies and reduced energy, chemical and space requirements. By making the beneficiation process more efficient and cost effective Sit will enhance the competitive position of clean and ultra-clena coal in the energy marketplace.

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vessel 12 exerts vertical pressure as well as radial pressure against the sides of the vessel 12. The height of the medium and its weight at a point in the vessel 12 controls the SUMMARY OF THE INVENTION.

In accordance with the present invention there is provided a process for combined size reduction, classification, and separation of' a desired constituent from an undesired constituent of mineral matter that includes the steps of introducing into a vessel a slurry of mineral matter particles of an initial size having a desired constituent physically connected to an undesired constituent. The slurry of mineral matter particles is directed in a first direction to a size reduction zone of the vessel.

A separation inducing fluid is injected under pressure into the vessel in a second direction opposite to the first direction into the size reduction zone. The fluid and the mineral matter particles are admixed in the size reduction zone. The particle size of the mineral matter is reduced from the initial size in the size redu-tion zone.The desired constituent in the mineral matter is liberated from physical connection with undesired constituent in the mineral matter. The desired constituent is entrained with the separation inducing fluid in a flow in the second direction from the size reduction zone to a separation t zone. The undesired constituent in the mineral matter is carried o rt in the first direction in the vessel away from the separation 0 zone to a refuse zone. The entrained desired constituent is 0,t discharged fiOc the separation zone of the vessel. The undesired constituent in the refuse zone is removed from the vessel.

Further in accordance with the present invention there is provided a beneficiation p:',cuss for combined size reduction, w, i- 6 classification and separation of minerals and other material that includes the steps of feeding for beneficiation into a vessel a slurry of mineral matter particles of an initial size having hydrophobic particles physically connected to hydrophilic particles.

The slurry of mineral matter particles is directed in a first direction to a size reduction zone of the vessel. Gas under pressure is injected into the vessel in a second direction opposite to the first direction to a size reduction zone.

The pressurized gas and mineral matter particles are admixed in the size reduction zone. The particle size of the mineral matter is reduced in the size reduction zone. Hydrophobic particles of the mineral matter are liberated from physical connection with the hydrophilic particles of the mineral matter.

Gas bubbles are generated as the pressurized gas passes through the size reduction zone. The hydrophobic and hydrophilic particles are admixed with the gas bubbles in the size reduction zone. The hydrophobic particles are attached to the gas bubbles to form a moving column of the hydrophobic particles entrained in a froth. The hydrophobic particles S entrained in the froth are discharged in the second direction from the vessel. The hydrophilic particles are retained in the slurry and settle in a refuse zone of the vessel. Thereafter the hydrophilic particles are removed from the refuse zone of

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~the vessel.

Additionally the present invention is directed to apparatus for producing a beneficiated mineral product that includes an tit( 1118

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C CC 18 the amount of material that needs to be reduced to a finer size. An increase in the height of the classifying zone would enhance the efficiency with which the liberated nartIr'1p i, -7 elongated vessel hving a first end portion with an opening and a second end portion with an opening. An inlet in the vessel is positioned intermediate the first and second end portions for introducing into the vessel a flow of a slurry of mineral product. Means is positioned in the vessel for agitating the mineral product to reduce the particle size of the mineral product into a valuable constituent and a ~efuse constituent. The valuable constituent is less dense than the refuse constituent. The valuable constituent is separated from the refuse constituent by flow of the valuable constituent in a first direction in the vessel with the fluid and flow of the refuse constituent in a second direction opposite to the first direction the vessel. An outlet in the opening of the vessel first end portion is provided for discharging the flow of the valuable constituent in the first direction from the vessel. An outlet in the opening of the vessel second end portion is provided for discharging the refuse constituent from the vessel.

Further in accordance with the present invention there is \1 provided a mill for the simultaneous size reduction of particulate i mineral product and separation of the valuable mineral constituent l from the gangue that includes an elongated vessel hving an inlet for receiving a slurry feed of particulate mineral product, a first outlet for discharging the valuable mineral tconstituent, and a second outlet for discharging the gangue.

Agitating means positioned in the vessel adjacent to the second outlet fractures the particulate mineral product into a valuable mineral constituent to form a froth.

The valuable mineral constituent is entrained in the froth 1 1 19 above described. The agitator 15 as shown in Figures 1 and 2 includes helical spirals 16 but it should also be understood that- the aittor mav include rotatino and flows in the vessel in a first direction for discharge through the first outlet. The gangue is entrained in the slurry feed and flows in a second direction opposite to the flow of the valuable mineral constituent in the first direction in the vessel for separation from the valuable mineral constituent and removal from the vessel through the second outlet.

Accordingly, the principal object of the present invention i3 to provide an improved size reduction and mineral separation method and apparatus for producing a cost competitive carbonaceous material as an energy source.

A further object of the presehnt invention is to provide a process for the beneficiation of carbonaceous and noncarbonaceous minerals, ferrous and nonferrous ores, and other materials that simultaneously performs the operations of size reduction of material and the separation of the refuse or undesirable constituentsd from the desirable constituents in one chamber or vessel.

An additional object of the present invention is to provide method and apparatus for energy efficient size reduction of mineral matter separation of valuable constituent from the gangue by froth flotation in a single vessel.

(P t Another object of the present invention is to provide 4 1 t a method for accomplishing combined size reduction, classification, 1 Figure 8 illustrates a further embodiment of the present invention of the mill 10 that includes a plurality of circumferentially spaced separation zone vessels 64, each similar in eee~ and separation of mineral material in a continuous mode that utilizes on-line analyzers to control solids and fluids flow and other operating variables to achieve a cost efficient upgrading of mineral material.

These and other objects of the present invention will be more completely disclosed and described in the following specification, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic elevational view of a mineral beneficiation vessel in accordance with the present invention.

Figure 2 is a view similar to Figure 1, illustrating another embodiment of a mineral beneficiation vessel in accordance with the present invention.

Figures 3-8 are schematic illustrations of further embodiments of a beneficiation vessel.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings and particularly Figures 1 and c tc it 5 4 4 4 S 4: 21 transmitted upwardly into the separation zone 34. Consequently a relatively quiescent condition of the separation zone 34 is n vrnir4 A A vFnv -Fr« rn4 4n .F 4r\1- U 8 2, there is illustrated a size reduction and separation mill generally designated by the numeral 10 that includes a vessel 12 in the shape of an elongated tubular column preferably positioned upright, but which may be reclined at an angle or having portions positioned horizontally as shown in Figures 4-6, filled with grinding balls 14. The balls 14 are agitated in one mode by an agitator or rotor 15 having double helical spirals or paddles 16. The agitator 15 is rotated by a power source, such as a motor 18, connected to the end of the rotor extending from the bottom of the vessel 12.

The mineral material, such as coal, to be ground is introduced as a slurry 23 near the middle or intermediate portion 20 of the vessel 12 by means of a raw feed pipe 22 and a slurry pump 25. The slurry 23 is forrmed by combining the raw material particles and water in a mixture slurry tank 24.

The slurry 23 may be continuously recycled by means of a recycle pipe 27.

Air or gas is introduced into the mill 10 near a lower portior or bottom of the vessel 12 and is gauged by means of an air or gas flow meter 28. Froth flotation or other separation inducing fluids and chemicals are introduced into the mill 10 with or separately from the slurry 23. Wash water 37 i is added near the top of the mill 10 by means of a water inlet and nozzle 30. The water flow is controlled and monitored by means of a flowmeter 31. The lever of the slurry in the column is monitored by suitable means.

The weight of the balls and the movement of the balls in the vessel 12 cause size reduction of the material by attrition and shear, as well as by compression and impact. The reduction process may be varied by changing a number of factor which permit changes to be made in the rate of size reduction of the material into a valuable constituent, such as organic material, and an undersized constituent, such as gangue. The proportion of valuable constituent to undersired constituent is also variable. The variable factors include adjustments to the height of the grinding medium in the vessel 12 and the charge size of particles comprising the grinding medium.

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1 i 22 valuable constituent is discharged from the outlet 36 and the middling or undesirable constituent is discharged from the seDaration zone 34 tlhrniii,h ha c9 i ;I111~_ ii The grinding medium in the form of the balls 14 is under constant stress by the action of the vertical pressure load generated by the ball charge in the vessel 12 and the radial pressure exerted by the ball cL-rge against the walls of the vessel 12. Fracture of the mineral material can also be accomplished by an agitating device as shown in Figure 7 without use of a grinding medium in the form of balls. In addition the present invention includes fracture of the material by generating ultrasonic energy using conventional methors and apparatus in the vessel 12. The slurry feed is Sexposed to the ultrasonic energy. As a result the desired Sconstituent is liberated from the undesired constituent. In all operations of fracturing the mineral material to be ,,Ur beneficiated a multiplicity of loading and unloading cycles of multidirectional forces, both vertical and radial are applied Sto the mineral material.

The particles of the mineral material in the slurry feed Sare fractured as shown in Figures 1 and 2 by grinding balls 14 to liberate from the particles the valuable constituent and the undesired constituent. Fracture of the particles occurs when the forces acting on the particles exceeds the tensile Sstrength of the particles of mineral material. With this i:t arrangement the forces generated at the bottom of the ball charge are the greatest. Preferably forces are generated only to the magnitude required to liberate the locked particles Sfrom the unlocked particles.

A higher proportion of unliberated (locked) particles exist at the bottom of the vessel than at the top of the ball charge. The liberated particles when unlocked rise to the top of tha ball charge where the forces are less than the forces required to fracture the particles. At this point scrubbing of the liberated particles takes place to remove slimes and other detrimental materials from the surface of the particles.

The feed size of the slurry into the vessel 12 must be optimized with both the liberation and separation characteristics of the mineral material to be beneficiated. A finer feed size increases the capacity of the mill by increasing the 23 form the agglomerates which are separated from the nonagglomerated material; selective flocculation in which the flocculant rate of liberation of the valuable constituent from the undesirable constituent. Also an increase in the height of the ball charge will increase the rate at which the valuable constituent and gangue are liberated to further increase the production capacity of the mill The ball charge may be comprised in one method of operation a selected distribution of ball sizes where the Darticles size of the slurry feed is substantially uniform. The grinding medium is added to the vessel 12 in two forms. First, the coarest ball size is used at regular intervals and in predetermined amounts. Preferably the ball charge size ranges from a maximum size to a minimum size. The size distribution is also effected by the wear characteristics of the balls.

In a second mode of operation balls of two or more sizes are added in predetermined amounts at predetermined intervals based on wear characteristics of the balls. The ball charge g..t size distribution is controlled to provide the maximum effectiveness in the liberation of the valuable constituent from the Smineral material and separation from the gangue. Other factors which influence the reduction process include the diameter of the vessel 12, the pitch of the helical spirals 16 Sof the agitator 15, the clearance between the spirals 16 and the walls of the vessel 12, the rate of rotation of the S agitator 15, the packed bed porosity of the ball charge, the nature of the balls, and the rate of erosion of the balls.

As illustration in Figure 1 the vessel 12 is partially filled with the balls 14 to form a bed of balls interspersed with a large number of small flow passages 32 extending in a Icircuitous pattern between the upper and lower portions of the vessel 12. The balls 14 can be discharged from the vessel 12 through valved outlet 31. In one mode of operation as further illustrated in Figure 1 wash water is introduced into the upper portion of the vessel 12 and dispersed from the nozzle The slurry 23 is introduced into a classifying zone 33 located in the intermediate portion 20 of the vessel 12 flows downwardly through the passages 32.

Pressurized gas is introduced into the lower portion or 24 constituent. The heavy liquid with this material is carried downwardly, and the liquid phase into the grinding zone 40 of the vessel 12.

ii refuse zone 42 of the vessel 12 through the gas inlet 26 and is forced upwardly through a grate 43 that supports the bed of balls 14 in the vessel 12. The upward flow of pressurized gas is counter to the downward flow of water 30 and slurry 23 through the flow passages 32. When the agitator 15 in the size reduction or grinding zone 40 is rotating, the balls 14 are moving in the vessel 12 so that the configuration of the passages 32 is changing continuously.

As the gas passes through the flow passages 32 formed by the charge of balls 14, the gas is broken up into fine bubbles of relatively uniform size. These bubbles rise upwardly in the vessel and intimately contact the mineral particles of the slurry 23 in the flow passages 32 to produce a froth. The S froth consists primarily of hydrophobic particles along with a S minor amount of gangue/refuse material entrained in the froth.

o O Along with the completely liberated mineral particles, locked particles consisting of varying proportions of the valuable constituent and the gangue or undesirable constituent become attached to the fine bubbles and rise with the bubbles.

The air bubbles carry the clean concentrate product upwardly into a separation compartment or zone 34 in the upper portion of the vessel 12. From the separation compartment 34 S the product is discharged through a concentrate outlet 36 in S the direction indicated by the arrow 38. Wash water from the nozzle 30 descending through the passages 32 in the bed of balls 14 passes the mineral particles laden froth and induices the entrained mineral particles and the less hydrophobic particles to separate from the clean product 38 discharged from the outlet 36 and to be carried downwardly in the water phase into the grinding zone This slightly hydrophobic, nonliberated material is further ground in the grinding zone 40 with the feed material so that the valuable material is more completely liberated.

The tailings (gangue and refuse) fraction containing the non-floatable particles collect in the refuse zone 42 at the bottom of the vessel 12 and are discharged through an outlet conduit 45 controlled by a valve 44. A suitable fluid slurry occurs based on density, distribution and grade. The nonfloatable and slow-floating near gravity material is ground to the finer size in the size reduction compartment of the mill _i I P\1 12 level is maintained in the vessel 12. This is accomplished by operation of the variable flow slurry pump Thus the degree of grinding and removal of material from the mill 10 is dependent on the quality of the refuse and concentrate. The valuable mineral particles are removed from the size reduction zone 40 as soon as they are generated. The size reduction operation is also performed primarily on slightly "off-spec" hydrophobic nonliberated material with the feed slurry 23. In t!'is manner the valuable constituent is more completely liberated from the raw material. The tailings containing gangue and refuse contain the non-floatable particles which collect in the refuse zone 42 or tailing chamber 42 at the bottom of the vessel 12. The tailings are discharged 'j through the valued conduit 45 controlled by valve 44. The result is that the material is not ground to a size finer than *Irc is necessary to achieve the concentrate grade and recovery required. In this manner the grinding efficiency and energy required for the size reduction is kept to a minimum.

In the mill 10, the rising air bubbles carry the floatable particles upward, and the water phase carries the non-floatable particles downwardly. The net effect is that the most floatable particles reach the concentrate discharge outlet 36 first and S the most non-floatable move downward toward the tailings ;t discharge outlet 45 at the fastest rate. Feed material is continuously fed into the mill feed pipe 22. The incoming feed particles will continually redistribute and have a tendency to push each other from the feed point toward either of the two outlets 36 and Stratification of the material occurs at a steady-state operating condition and is based on floatability and grade of the material. The non-floatable and slow-floating material is reduced to a finer particle size in the lower size reduction section 40 of the mill 10 and is immediately separated and classified on the basis of grade. The grade gradient is controlled with an on-line analyzer by changing any of the flow parameters which change the mass balance and water balance, and the size reduction parameters which change 26 zone 40. The hydrophilic mineral particles settle out of the size reduction 40 and into the refuse zone 42 for removal from the mill 10. Agglomerates of locked particles remain in the IA~r u1 r I I 13 the rate of size reduction of the material to liberation size and thus change the proportion of the floatable and nonfloatable material in the system available for separation.

One of the major advantages of the mill 10 of the present invention is the ability to perform a plurality of unit operations in one device such as: size-reduction, (2) classification, conditioning, scrubbing, froth flotation, regrinding or size reduction of middlings, and reflotation or beneficiation of middlings. These process steps are diagrammatically illustrated in the following example.

Feed G [Cassify Condition Froth Feed -Grindlj Classif Scrub Flotation Concentrate Cone.

Tails I 4 savings in capital and operating erosts. The above example tioner. The condition Froth grade Smiddling slurry is dewate crubb in Flound tat io Tails Use of the present invention will result in significant savings in capital and operating costs. The above example shows a typical froth flotation regrind circuit. Product from conducted in onerod mill or any other single vessel resultinze reduction device is ground in a(1) tumbling ball mill with a classifier. The product is scrubbed in a scrubber and then conditioned with chemicals in a conditioner. The conditioned slurry is then subjected to frothdly into flotation. The high grade concentrate is removed and the low grade middling slurry is dewatered and reground to liberation size. This reground material is subjected to further conditioning. In the present invention all of these operations are conducted in one mill or a single vessel resulting in (1) ii t- 27 component is leached into the fluid and rises upwardly into Ithe separation zone 34 where it is removed from the vessel 12.

The spent material is collected in the refuse zone at the :I .i lower capital costs, reduced operating costs, reduced maintenance costs, reduced water requirements, reduced space requirements, and reduced energy requirements. Thus the floatable particles can be more effectively separated from the non-floatable particles with a single stage flotation.

n the present invention, the size reduction of the particles results in the production of a new surface which instantaneously comes in contact with the added chemical and/or the fresh air/gas bubble and rises to the top. This is in sharp contrast to conventional systems in which there is a relatively large time elapse between the production of the new surface, the addition of any of the chemical and the attachment of the surface to the bubble, and, beneficiation separation of Sthe material.

The agitation of the media results in the break up and formation of air/gas bubbles to small relatively uniform sizes. This tends to eliminate the need for a special device S in the bottom of the column or vessel for generating the fine air bubble.

With the embodiment of the size reduction and separation mill 10 shown in Figure 2, where like numerals shown in Figure 2 correspond to like parts illustrated in Figure 1 and described S t tlri hereinabove, the vessel 12 includes the size reduction compart- S ment or grinding zone 40 and the separation compartmelit or zone 34 which in the embodiment shown in Figure 2 also fu-.ictions O as a froth flotation section. The vessel 12 receives a slurry feed 23 from the raw feed pipe 22 and slurry pump 25 and water 39 from an inlet controlled by valve 41 into the grinding zone The slurry feed and water are mixed with the ball charge S contained in the grinding zone 40. The mixture of slurry feed, water and grinding balls 14 are agitated or moved by rotation of the agitator 15 which includes a rotatably driven shaft 17 that is rotatably supported by braces 47 in vessel 12 and extends upwardly through the top of the vessel 12 where it is also rotatably supported.

The helical spirals 16 of the agiltator 15 are positioned in the grinding zone 40; thus, there is little movement of the

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-:1 i I~j I~ ball charge in the separation zone or froth flotation section 34. Consequently, the movement of the ball charge in the grinding zone 40 is greater than the movement of the ball charge in the separation zone 34. This creates in the upper portion of the vessel 12 a quiescent froth flotation region where quiescent flotation occurs.

A gas under pressure is directed form a source 26 through valves 28 into the refuse zone 42 of the vessel 12. The gas injected into the slurry bed generates bubbles flow upwardly and encounter a continuously varying tortous path and downwardly flowing water. In this manner the hydrophobic or only slightly hydrophilic particles are removed from the desired constituent to be extracted from the outlet 36 of the vessel 12. The o gangue and other refuse is removed from the refuse zone 42 through the valved outlet 44.

°o.9 With the embodiments of the mill shown in Figures 1 and oo: 2, if the ball charge weight and column height of the ball go charge and size distribution remain constant an increase in S the feed rate of the slurry 23 into the vessel 12 will reduce S the rate of production of the liberated particles and accordingly, the rate at which the valuable constituent and undesirable constituent are removed from the vessel 12. In this instance oothe reduction capacity of the mill 12 is decreased; accordingly, the feed size is optimized according to both the liberation and separation characteristics of the material. This requires controlling the rate at which the slurry feed 23 is pumped into the vessel 12. A finer slurry feed size increases the capacity of the mill by virtue of the fact that the rate of S liberation of valuable constituent from the material is increased where the undesired constituent is efficiently removed. In the event that increased efficiency of separation of valuable constituent from undesired constituent is desired attention must be given to the rate at which the mineral materials is fed into the vessel and under certain circumstances where there is a need to increase the separation efficiency, the feed rate into the mill is reduced.

The grinding medium in the form of the ball charge in the r .1 28 STHE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS 1i. A process for combined size reduction, classification, and separation of desired constituent from an undesired 16 vessel 12 exerts vertical pressure as well as radial pressure against the sides of the vessel 12. The height of the medium and its weight at a point in the vessel 12 controls the pressures that are generated in the various directions. If the pressures generated are greater than those required to fracture the mineral material, the size reduction takes place.

If the pressures are less than the forces required to fracture the mineral material, then only scrubbing of the surface of the particles takes place.

As the slurry feed 23 flows downwardly into the ball charge of the vessel 12'the particles of mineral material in the slurry feed are subjected to progressively greater pressures and are fractured. The movement of the finer and more hydrophobic particles upwardly in the mill 10 brings them into contact with progressively reducted pressures. At this point Sscrubbing takes place resulting in dispersions of the liberated particles and cleaning of the particles surfaces of slimes and other detrimental materials. Accordingly, an increase in the height of the ball charge increases the rate at which the valuable constituent and gangue are liberated from the mineral materials fed into the vessel 12 and in turn increases the output capacity of the mill o Another factor to be considered in the operating efficiency of the mill 10 is the relationship between the particle size of the grinding medium and the particle of the slurry feed.

S The slurry feed size is controlled according to the size of the particles comprising the grinding medium. For a constant particle size distribution in the slurry feed, a finer ball S charge generates a finer product size where the mineral material is ground to an extremely fine size. Another factor to be considered is inherent separation taking place without exposure to a grinding medium as a result of the slurry feed size being reduced prior to entering the vessel 12. Upon entrance separation begins without a particle size reduction required to take place.

In one embodiment the grinding medium includes the addition of the coarsest ball size used at regular intervals ii.

29 2. A process as set forth in claim 1 which includes, discharging as the desired constituent of the mineral 17 and in predetermined amounts. Preferably the ball charge would range from a maximum particle size to a minimum particle size. The size distribution is dependent on the wear characteristics of the balls. The ball medium in another embodiment comprises two or more sizes added in predetermined amounts at predetermined intervals where the ball charge size distribution is a factor of the wear characteristics of the balls. Overall, the ball charge size distribution is controlled so as to achieve the maximum effectiveness to attain a preferred particle size of liberated product from the slurry feed.

The agitator 15 illustrated in the mills 10 shown in Figures 1 and 2 is rotated at a preselected rate. Accordingly, the greater rate of rotation, the greater the rate of grinding or size reduction of the mineral material to the desired e.G.

particle size of the liberated or desired constituent. The m o° greater the rate of rotation, the greater the grinding capacity o: and output of the mill 10. Preferably the agitator 15 is o rotated at a rate which produces a grinding capacity that S preferably liberates the valuable constituent from the mineral fImaterial by grinding to what is known as the liberation size to form the unlocked particles of valuable constituent in mixture with the gangue which is continuously being separated and removed from the valuable constituent. The grade of the Como Svaluable constituent and gangue also influence the amount of Smaterial present in the size reduction zone 40 of the mill S and also the slurry feed 23 into the mill Another factor to be considered in the operating efficiency of the mill 10 shown in Figures 1 and 2 is the relationship between the height of the classifying zone 33 and separation zone 34, the grade and recovery of the valuable product, and the amount of the nonfloating material entering in the size reduction zone 40. The rising column of gas bubbles and froth rising out of the grinding zone 40 meets the downwardly flowing slurry feed 23. This interaction allows the hydrophobic particles to be attached to the bubbles and froth and be carried into the separation zone 34. A portion of the feed material may never enter the size reduction zone, thus reducing instantaneously producing upon reducing the particle size new surfaces of desired constituent liberated from the the amount of material that needs to be reduced to a finer size. An increase in the height of the classifying zone would enhance the efficiency with which the liberated particles in the feed can be separated without further size reduction which would impact on the size distribution of the valuable product 38 that is collected.

As the bubbles and froth carry the hydrophobic particles through the classifying zone into separation zone, an opportunity is afforded for the less hydrophobic particles to be detached and settle downwardly back into the grinding zone. The particles that remain attached to the bubbles are collected at the top of the column in vessel 12. An increase in the height of the separation zone insures that only the most hydrophobic particles are recovered and thus enhance the grade or quality of the valuable constituent 38 collected.

The addition of the downwardly flowing wash water 37 Sthrough a sprayer 30 near the top of the separation zone 4:o detaches the more hydrophilic particles from the froth moving upwardly toward the outlet 36 and carries them downwardly "f t r-owards and into the grinding zone 40. By increasing the amount of wash water 37 and positioning of the sprayer in the separation zone, the more hydrophobic particles will remain attached to the bubbles and thus enhance the grade and quality 0o°° of the valuable constituent 38 collected. This step increases the amount of material that is carried back into the grinding O zone.

o4 Varying the heights of the classifying zone and separation zone, the rate of wash water, and the position of the wash S water influences the quality of the material 38 that is collected. This will also affect the quality of the gange, the rate at which the gange and valuable constituent are collected, the capacity of the mill, the amount of material present in the size reduction zone 40 of the mill, and the nature of the slurry feed 23 into the mill Now referring to Figures 3-8 there is illustrated further embodiments of the mill 10 in which like numerals shown in Figures 3-8 designate like parts as shown in Figures 1 and 2 31 A process as set forth in claim 1 which includes, injecting gas under pressure into the slurry of mineral 19 above described. The agitator 15 as shown in Figures 1 and 2 includes helical spirals 16 but it should also be understood that the agitator may include rotating pins or spokes 46 as shown in Figures 3-8. The pins are of varying length, cross section and shape and extend from the rotation shaft of the agitator 15. The pins generate force sufficient to fracture the mineral material without the need for the addition of grinding balls into the vessel.

As shown in Figure 1, as well as in Figures 3-8, the agitator 15 is rotated by a motor 18 from the bottom or from a drive connection at any point along the length of the agitator as for example, intermediate the agitator 15 as shown in Figure 6. In Figure 2 the agitator is driven by a suitable tote power means from the top of the vessel 12. As shown in Figure $Fit 7 size reduction is performed by means of two interacting discs 61 and 62, one stationary and the other rotating, or both rotating in opposite directions by operation of motor 18.

The discs have pins 63 of varying lengths, cross section and Sshape and extend from the rotating discs.

In Figures 1-3 the entire vessel 12 is vertically positioned but it may be positioned at any angle or have portions which are angled respect to each other such as shown in Figures 4 Sand 5 where the size reduction zone 40 is positioned horizontally relative to a vertically extending separation zone 34. In the a4 4" at a alternative the entire vessel 12 may be positioned horizontally S with the agitator 15 positioned within the vessel inclined S from the horizontal as shown in Figure 6.

While the respective compartments or zones of the mill 12 are aligned in one embodiment as shown in Figures 1-3, the compartments may be angularly oriented from one another to form discreetly separate zones. The mills 10 shown in Figures 4 and 5 have discreet separations between the reduction zone and the separation zone 34. In Figure 3 there is illustrated an arrangement where the mill 10 includes vertically aligned reduction and separation zones but a reduced area 48 in the diameter of the vessel 12 discreetly separates the two zones 34 and I carrying the desired constituent with the gas bubbles into the separation zone.

1 1 Figure 8 illustrates a further embodiment of the present invention of the mill 10 that includes a plurality of circumferentially spaced separation zone vessels 64, each similar in construction to separation zone 34 discussed above and illustrated Sin Figures 1 and 2. Like numerals of Figures 1 and 2 designate like parts shown in Figure 8 where each separation zone vessel 64 includes a reduced lower end portion 66 that communicates 8 with a distributor 68.

The size reduction zone 40 is formed by a vessel having a reduced upper end portion 72 connected axially with the distributor 68. A driven agitator 15, as shown in Figure 1, is positioned in the reduction zone vessel 70 which is also provided with a raw feed pipe 22 for the slurry input. A pipe 74 introduces a gas under pressure into the reduction zone A pipe 76 discharges the tailings from the vessel 70. In addition each separation zone vessel 64 includes conduits 78 (schematically shown in Figure 8) for recycling middlings from the vessel 64 back into vessel 70. Thus with the embodiment Qt 0 of the vessel 70 shown in Figure 8, the output of desired conituent from the plurality of outlets 36 from the multiplicity of vessels 64 is substantially increased.

Now referring to the embodiment shown in Figure 3, the •..wash water is introduced into the upper end portion of the vessel 12 through the nozzle 30 and the slurry feed is introduced through conduit 22 into the size reduction or grinding zone 0O0 40. In addition, gas is introduced from a source through valve 28 (shown in Figure 2) into the lower end portion of the vessel 12 and the size reduction zone 40. The desired constitst,0 uent is liberated from the mineral material and passes from oil.

the size reduction zone 40 through a plate knot shown in Figure 3) containing holes or a wire mesh located at a reduced diameter portion 48 of the vessel that separates the zones 34 and The presence of the plate at the reduced diameter portion 48 serves to isolate the separation zone 34 from the size reduction zone 40. This confines the agitation of the slurry feed to the size reduction zone 40 and the agitation is not admixing the gas and mineral matter particles in the size reduction zone, ii transmitted upwardly into the separation zone 34. Consequently a relatively quiescent condition of the separation zone 34 is provided for efficient separation of the concentrate which is discharged from the outlet 36 from the middling or gange. The middling which passes from the size reduction zone 40 into the lower end portion of the separation zone 34 is recycled from the separation zone segment of the vessel 12 back into the size reduction segment of the vessel for further grinding.

SThe refuse is discharged from the lower end portion of the vessel 12 out of the size reduction zone Now referring to Figure 4, there is illustrated an embodiment of the mill that corresponds to the embodiment shown in Figure 3 with the modification of orienting the portion of the vessel 12 that comprises the size reduction zone 40 horizontally relative to the vertically extending 4t portion which comprises the separation zone 34. With the embodiment shown in Figure 4, not only is middling from the separation zone 34 recycled back into the size j reduction zone 40, but is also admixed with the slurry feed which is introduced into the size reduction zone fThe mills 10 shown in Figure 5 includes a pair of vessels 12 corresponding to the single vessel 12 shown in Figure 4.

ft With the arrangement shown in Figure 5 a first vessel 12A Sreceives an input of slurry feed and gas into the size reduction zone 40 in the manner above described where the valuable constituent is liberated from the gangue and discharged from the outlet 36. The undesirable constituent, having been separated from the concentrate, is discharged from the separation zone 34 through outlet 50 and is introduced as input into the S size reduction zone 40 of the adjacently positioned vessel 12B *As with the vessel 12A, gas is introduced into the separation zone 40 of 12B. The mixture is agitated to produce further size reduction and separation of valuable constituent from the gangue. The mixture of valuable constituent and gangue advances from the size reduction zone 40 into the lower end portion of the separation zone 34 where the valuable constituent is separated from the gangue or middling. The II A 34 introducing wash water into the separation zone, and inducing the less hydrophobic particles and middling product in the froth to separate from the hydrophobic i u I r 22 valuable constituent is discharged from the outlet 36 and the middling or undesirable constituent is discharged from the separation zone 34 through the outlet 52.

And now referring to Figure 6, there is shown an embodiment of the mill in which the vessel 12 includes as the size reduction zone 40 a compartment 79 positioned at an angle inclined from the horizontal where the separation zone 34 extends upwardly from the size reduction compartment 79, With this arrangement, the slurry feed and gas are introduced through inlets 54 and 56 at one end of the size reduction compartment 79. The agitator 15 is driven intermediate its end portions in the compartment 79, At the opposite end of compartment 79 refuse is discharged through outlet 58.

The liberated valuable con.tituent rises upwardly in the manner as above described from the size reduction compartment °40 into the separation zone 34 and is discharged from an a outlet (not shown in Figure 6) from the upper end portion of the separation zone 34. The hydrophilic and only slightly oo hydrophobic particles are separated from the concentrate in the zone 34 and are removed from the vessel through outlet and may be recycled, as illustrated, back into the size reduction compartment 79 or completely removed from the vessel 12.

o Similarly with the arrangement shown in Figure 7 the S rotating discs 61 and 62 reduce the particle size of the o mineral material in the size reduction zone 40. Slurry feed 0 and gas are introduced through inlets 54 and 56 at one end of zone 40. Refuse is discharged from zone 40 through outlet 58.

,It should also be understood that the present method and S apparatus is particularly designed for providing an improved means for beneficiation of carbonaceous and noncarbonaceous mineral material, as well as in other embodiments such as; true heavy media separation when the heavy liquid is used instead of water so as to make separation based on differences in thO density of the constituents; selective agglomeration in which oil, other hydrocarbon, or an agglomerant is introduced into the mill to an inlet in said vessel positioned intermediate said first and second end portions for introducing into said vessel a flow of slurry of mineral product, form the agglomerates which are separated from the nonagglomerated material; selective flocculation in which the flocculant is added with the fluid so that certain components of the material cau be selectively flocculated and separated as soon as these components are liberated; leaching where the leaching fluid is used instead of water so as to selectively dissolve components in the material being treated; and homogenizer for comminuting and mixing of substances, especially of various solids, or solids, liquids and gasses, for producing a homogeneous mixture of the various substances which in conformity with the requirements are uniformly distributed and comminuted.

More specifically, with the heavy liquid separation method a mill as described above and illustrated in Figure 1-7 'ff1 is utilized where the material to be ground is introduced with I*Ot chemicals in the nature of heavy liquid having a predetermined density at approximately middle of the vessel 12 in slurry form. A suitable pulp lever is maintained in the vessel and additional heavy liquid is introduced into the vessel near the bottom thereof. The movement of the grinding balls 14 or other agitating means in the manner above described acts upon 0Oo the slurry to reduce the size of the particles in the slurry.

.0 O The size reduction takes place in the size reduction zone or 040 compartment 40 of the vessel 12. The size reduction is generated as a result of attrition, shear, and to a lesser degree, by compression and impact.

t, The heavy liquid flows downwardly through the flow passages that extend in a circuitrous pattern between the upper and lower portions of the vessel 12. The lower density desired constituent rises upward into the upper portion or separation zone of the vessel 12 and is discharged through the concentrate outlet 36. The heavy liquid descending through the small flow passages interspersed throughout the bed of ball charge induces the entrained mineral material and the higher density particle to separate from the unlocked desired

A'.

36 22. Apparatus as set forth in claim 21 which includes, means for directing a flow of wash water in the second direction in said vessel through said mineral nrodtint- -nc -4A i:

T

24 constituent. The heavy liquid with this material is carried downwardly, and the liquid phase into the grinding zone 40 of the vessel 12.

In this manner, as above described, the higher specific gravity ("off-spec"), non-liberated materials further reduced in size so that the valuable constituent is more completely liberated. The refuse, such as high ash particles, is collected in the refuse zone 42 and is discharged therefrom through the valued outlet 44.

In the heavy liquid method of separation and according to the present invention, the size reduction of the mineral material, such as coal, results in the production of particles which are organic-rich and mineral matter-rich. These particles instantaneously come in contact with the heavy liquid. The particles either rise toward the top and out of the size ,tI reduction zone or, sink to the bottom and finally out of o the size reduction zone, or remain substantially in the size reduction zone for further grinding and liberation. As a S result there is less tendency of refuse to attache, or agglomi erate, or be entrained in the clean coal. Moreover, since the particles that need to be reduced to liberate the coal remain in the size reduction zone, production of fines is kept to a minimum. This is in contrast to conventional systems in which rsnO o* there is a relatively large time lapse between the production of the new surface and the separation of the coal from the refuse. As a result, a sinxgle stage device is provided with is equivalent to a multiple stages in a conventional circuit.

In the heavy liquid method of separation, the heavy liquid carries the lower density particles upward, while the So particles move downward. The net effect is that the most floatable particles reach the concentrate discharge point and the most non-floatable move downwardly toward the tailings discharge point at the fastest rate. Material is fed contin- 3 uously'i:nto the mill near the middle of the vessel. The incoming feed particles will continually redistribute and have a tendency to push each other away from the feed point toward either of the two outlets. A stratification of the material 37 27. A mill when used according to the process of any one of claims 1 to 19, for the simultaneous size reduction of particulate mineral product and separation of the valuable mineral constituent from thp nnnnm nrmr%,- :i occurs based on density, distribution and grade. The nonfloatable and slow-floating near gravity material is ground to the finer size in the size reduction compartment of the mill and is immediately separated on the basis of grade. This is also in sharp contrast to conventionally grinding mills where the separation is based primarily on particle size.

In the beneficiation process that utilizes separation by selected agglomeration the ball mill 10 as above described is also utilized where the ball charge forms a large number of small flow passages that extend in a circuitous pattern between the upper and lower portions of the vessel 12. With this method a small amount of water is introduced into the lower portion of the vessel with the selected agglomerate, such a naptha, heptane and the like, and is forced upwardly o through the flow passages. As the agglomerate passes through kbo"* the flow passages in the grinding balls, it is broken up and be 9 dispersed evenly in the mill. The selected agglomerate intimately contacts the desired constituent that has been liberated from the mineral matter in the flow passages to produce agglomerates consisting primarily of the desired constituent. The liberated constituent and agglomerates mov,- upwardly into the upper portion or the separation zone 34 of the vessel 12 and are discharged through the concentrate A, outlet 36. The hydrophilic particles separate from the 00 0 desired constituent and are carried downwardly in the water phase into the size reduction zone 40 of the vessel 12.

The slightly "off-spec", non-liberated material is further reduced in size so that the desired constituent is more completely liberated from the mineral material. The a refuse settles downwardly through the size reduction zone to the refuse zone 42 where it is discharged through a valve outlet.

Size reduction of the mineral material as above described, generates new surfaces consisting of liberated desired constitueits, mineral particles, and locked particles. The valuable constituert particles instanteously come in contact with the added agglomerate and move upwardly out of the size reduction 1 38 said valuable mineral constituent being liberated from said particulate mineral product in said reducing compartment, and qn i 1d4 26 zone 40. The hydrophilic mineral particles settle out of the size reduction 40 and into the refuse zone 42 for removal from the mill 10. Agglomerates of locked particles remain in the size reduction zone 40 where the grinding action of the balls 14 liberate the mineral matter and separate it from the agglomerate. In this manner the possibility of refuse slimes remaining attached or being entrapped by the large surfaces is substantially reduced.

Further, in the selective flocculation method of beneficiation the mineral material is also introduced near the top or into the size reduction zone 40 of the mill 10 and moves downwardly toward the bottom of the vessel 12. The slurry feed interacts with the selected flocculant which is introduced 9000 near the bottom of the size reduction zone 40 and moves B. upwardly. In the size reduction 40 the selective flocculant is dispersed evenly throughout and comes into intimate contact with the liberated material to be flocculated.

0990 99 9" The flocculated material is removed from the size reduction o 09 °zone 34 by the upward flow of the fluid into the quiescent separation zone 34 where it is removed as above described from the 'ressel 12. The material which is not flocculated settles to the bottom of the vessel 12, for example, in the refuse zone 42 and is discharged in a controlled manner through the 0009 S valved outlet 44.

Leaching operations can also be performed in the beneficiation process of the present invention. Accordingly, various operations of size reduction of the mineral material, leaching of a component, separation of the leachate, and oa removal of the spent material from which the valuable component S has been removed are conducted in the single vessel ball mill of the present invention. The mineral material slurry feed is introduced into the upper portion of the size reduction zone 40 and moves downwardly toward the bottom. The slurry feed interacts with the fluid introduced near the bottom of the vessel 12 and moves upwardly through the size reduction zone 34. The size reduction takes place in the manner above described and as a result of the agitation generated, the I .3 39 said valuable mineral constituent being carried by said fluid under pressure from said reducing compartment to said separating compartment immediately upon liberation from said I: 27 component is leached into the fluid and rises upwardly into the separation zone 34 where it is removed from the vessel 12.

The spent material is collected in the refuse zone at the bottom of the vessel 12 and is discharged therefrom. By varying the operating parameters, such as feed rate, residence times, leaching fluid type and flow rate, the process can be selectively controlled.

Accordingly to the provision of the patent statutes, I have explained the principle, preferred construction and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiments.

However, it should be understood that, within the scope of the appended claims, the invention may be practiced, otherwise than as specifically illustrated and described.

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a separation zone spaced from said grinding zone for receiving the valuable mineral constituent liberated from said slurry feed in said grinding zone, and

Claims

2. A process as set forth in claim 1 which includes, discharging as the desired constituent of the mineral matter hydrophobic carbonaceous particles from the separation zone of the vessel, and removing as the undesired constituent of the mineral matter hydrophilic, non-floating noncarbonaceous particles from the re- fuse zone of the vessel.
3. A process as set forth in claim 1 which includes, partially filling the vessel with a bed of grinding balls in the size reduction zone, agitating the grinding balls to define a plurality of flow passages throughout the bed of grinding balls extending in a circuitous pattern in the size reduction zone, generating the gas bubbles by the flow of the pressurized gas through the flow passages, and breaking up the gas bubbles to produce gas bubbles of reduced size by agitation of grinding balls.
4. A process as set forth in claim 3 which includes, intimately admixing the gas bubbles with the desired constituent in the flow passages to produce a froth, and carrying the froth out of the size reduction zone for separation from the undesired constituent in the vessel.
5. A process as set forth in claim 1 which includes, reducing the particle size of mineral matter in the size reduction zone by compressing the matter between grinding S: balls and the interior wall of the vessel, and /0 3/rL I a instantaneously producing upon reducing the particle size new surfaces of desired constituent liberated from the undesired constituent of the mineral matter.
6. A process as set forth in claim 1 which includes, comminuting particles of the mineral matter by vibrating a bed of grinding balls in the size reduction zone to fracture the particles of mineral matter by contact with the vibrating grinding balls.
7. A process as set forth in claim 1 which includes, generating ultrasonic energy in the size reduction zone, exposing the slurry of mineral matter to the ultrasonic energy, and fracturing the particles of the mineral matter upon exposure to the ultrasonic energy to liberate the desired constituent from the undesired constituent.
8. A process as set forth in claim 1 which includes, reducing the particle size of mineral matter in the size reduction zone by compressing and shearing the matter by rotating grinding discs, and instantaneously producing upon reducing the particle size new surfaces of desired constituent liberated from the 1 undesired constituent of the mineral matter. t C,
9. A process as set forth in claim 1 which includes, comminuting particles of the mineral matter by impact with high speed impellers in the size reduction zone to fracture the particles of mirneral matter by contact with the impellers. r r C i WASH WATER WASH WATER 36 /2 /2 /0r '7 i 12 31 A process as set forth in claim 1 which includes, injecting gas under pressure into the slurry of mineral matter to form bubbles in the vessel, attaching hydrophobic particles forming the desired constituent to the bubbles to form a froth, moving the froth from the size reduction zone to the separation zone, retaining less hydrophobic particles forming the undesired constituent in the size reduction zone for further fracture and size reduction to liberate additional hydrophobic particles from the mineral matter, and carrying the additional hydrophobic particles by a stream of gas bubbles into the froth.
11. A process as set forth in claim 1 which includes, directing wash water downwardly through the separation and size reduction zones, and causing the undesired constituent and less hydrophobic particles to flow with the wash water and separate from the desired constituent and more hydrophobic particles. g 12. A process as set forth in claim 11 which includes, generating ultrasonic energy in the separation zone, and exposing the slurry of mineral matter to the ultrasonic energy.
13. A process as set forth in claim 1 which includes, admixing gas under pressure with water to generate bubbles in the size reduction zone, and ]i ;_i 32 carrying the desired constituent with the gas bubbles into the separation zone.
14. A process as set forth in claim 1 which includes, collecting middling and less hydrophobic particles from the separation zone, entraining the middling and less hydrophobic particles in a flow of wash water to the size reduction zone for separation from the desired constituent, and subjecting the middling and less hydrophobic particles to further size reduction in the size reduction zone. A process as set forth in claim 1 which includes, collecting refuse in the form of non-floatable particles in a refuse zone of the vessel, and discharging the refuse from the refuse zone through an outlet of the vessel.
16. A beneficiation process for combined size reduction, classification, and separation of minerals and other material comprising the steps of, feeding for beneficiation into a vessel a slurry of mineral matter particles of an initial size having hydrophobic par- tides physically connected to hydrophilic particles, i t directing the slurry of mineral matter particles in a first direction to a size reduction zone of the vessel, injecting gas under pressure into the vessel in a second direction opposite to the first direction into the size re- duction zone, S SS S rr*r r i admixing the gas and mineral matter particles in the size reduction zone, reducing the size of the mineral matter particles from the initial size introduced in the size reduction zone, liberating the hydrophobic particles of the mineral matter from physical connection with the hydrophilic particles of the mineral matter, generating gas bubbles as the pressurized gas passes through the size reduction zone, admixing the hydrophobic and hydrophilic particles with the gas bubbles in size reduction zone, attaching the hydrophobic particles to the gas bubbles forming a moving column of the hydrophobic particles entrained in a froth, discharging the hydrophobic particles entrained in the froth in the second direction from the vessel, retaining the hydrophilic particles in the slurry, settling the hydrophilic particles in a refuse zone of the vessel, and rus thereafter removing the hydrophilic particles in the refuse zone from the vessel. S. 17. A beneficiation process as set forth in claim 16 which includes, carrying the hydrophobic particles entrained in the ;froth upwardly in the vessel to a separation zone, t it t A 34 introducing wash water into the separation zone, and inducing the less hydrophobic particles and middling product in the froth to separate from the hydrophobic particles by flowing wash water into the size reduction zone. 1 8. A beneficiation process as set forth in claim 1 6 which includes, grinding the slurry of mineral matter in the size reduction zone to form more hydrophobic particles, instantaneously removing the hydrophobic particles upon reducing the particle size by flotation in the vessel to a separation zone, and returning the less hydrophobic particles to the size reduction zone for further grinding to release additional hydrophobic particles.
19. A beneficiation process as set forth in claim 16 which includes, agitating a bed of grinding balls in the vessel to fracture the minei'a matter in the slurry feed to release the hydrophobic particles, passing the pressurized gas through passages formed in the agitated bed of grinding balls, carrying the less hydrophobic particles in the vessel for separation from the froth. Apparatus for producing a baneficialed mineral product when used according to the process of any one of claims 1ito 19 comprising, an elongated vessel having a first end portion with an opening and a second end portion with an opening, -7 an inlet in said vessel positioned intermediate said first and second end portions for introducing into said vessel a flow of slurry of miineral product, means positioned in said vessel for agitating the mineral product to reduce the particle size of the mineral product into a Jaluable constituent and a refuse constituent, said valuable constituent being less dense than said refuse constituent, said valuable constituent being separated from said refuse constituent by flow of said valuable constituent in a first direction in the vessel with said fluid and flow of said refuse constituc. in a second direction opposite to the first direction in said vessel, an outlet in said opening of said vessel first end portion for discharging the flow of said valuable constituent in the first direction from said vessel, and an outlet in said opening of said vessel second end portion for discharging said refuse constituent from said "o vessel.
21. Apparatus as set forth in claim 20 which includes, a reducing zone in said vessel second end portion, :2 said agitating means including a grinding medium disbursed throughout said reducing' zone to form a plurality of flow passages extending in a circuitous pattern throughout said t) i grinding medium, and ri means for injecting said fluid under pressure in said reducing zone into contact with said grinding medium -o form a ,t plurality of bubbles passing in the first direction through 'Isaid circuitous flow passes. -0S I J 36
22. Apparatus as set forth in claim 21 which includes, means for directing a flow of wash water in the second direction in said vessel through said mineral product and said grinding medium.
23. Apparatus as set forth in claim 20 which includes, means for removing the refuse constituent from said vessel and recycling said refuse constituent into contact with said agitating means to further reduce the particle size of said refuse constituent to release therefrom said valuable constituent.
24. Apparatus as set forth in claim 20 which includes, means for adding chemicals to alter the surface characteristics of said valuable and refuse constituents as soon as said constituents are formed as a result of size reduction of said mineral product. Apparatus as set forth in claim 20 which includes, said vessel first end portion being maintained in a first position with said vessel second end portion being maintained in a second position at an angle with respect to said first end •:"portion.
26. Apparatus as set forth in claim 20 which includes, said vessel first end portion being vertically positioned and said vessel second end portion being horizontally posi- tioned with respect to said first end portion. €€1Q C C 37
27. A mill when used according to the process of any one of claims 1 to 19, for the simultaneous size reduction of particulate mineral product and separation of the valuable mineral constituent from the gangue comprising, an elongated vessel having an inlet for receiving a slurry feed of particulate mineral product, a first outlet for discharging the valuable mineral constituent, and a second outlet for discharging the gangue, agitating means positioned in said vssel adjacent to said second outlet for fracturing said particulate mineral product into a valuable mineral constituent and a gangue, an inlet for introducing fluid under pressure into said mixture with said valuable mineral constituent to form a froth, said valuable mineral constituent being entrained in said froth and flowing in said vessel in a first direction for discharge through said first outlet, and said gangue being entrained in said slurry feed and flowing in a second direction opposite to the flow of said valuable mineral constituent in the first direction in said vessel for separation from said valuable mineral constituent and removal from said vessel through said second outlet.
28. A mill as set forth in claim 27 which includes, a reducing compartment of said vessel for positioning said agitating means and receiving said slurry feed, a separating compartment spaced from said reducing compartment in said S• vessel, SC 4 IL C CL C i- 38 said valuable mineral constituent being liberated from said particulate mineral product in said reducing compartment, and said valuable mineral constituent being carried by said fluid under pressure from said reducing compartment to said separating compartment immediately upon liberation from said mineral product.
29. A mill as set forth in claim 27 in which, said agitating means includes a bed of grinding balls in said vessel, said fluid under pressure being injected in the first direction in said bed of grinding balls and said slurry feed being injected in the second direction in said bed of grinding balls to form a plurality of flow passages interspersed in a circuitous pattern throughout said bed of grinding balls to facilitate separation of the valuable mineral constitute from the slurry feed and forming a rising column of froth, and said valuable mineral constituent being entrained in said :froth to flow in the first direction in said vessel out of mixture with said gangue.
30. A mill as set forth in claim 27 which includes, a reducing compartment of said vessel for receiving said slurry feed, Ira separating compartment spaced from said reducing compart- C ment in said vessel, said valuable mineral constituent being liberated from C said particulate mineral product in said reducing compartment, and I r_ J 39 said valuable mineral constituent being carried by said fluid under pressure from said reducing compartment to said separating compartment immediately upon liberation from said mineral product.
31. A mill as set forth in claim 27 which includes, an inlet for introducing fluid into said mixture with said valuable mineral constituent to form agglomerates and flocculants, said valuable mineral constituents flowing in the first direction in said vessel for discharge through said first outlet, and said gangue flowing in the second direction in said vessel for subsequent removal through said second outlet.
32. A mill as set forth in claim 27 which includes, means for continuously injecting a feed of slurry into said vessel toward said agitating means, means for adding a surfactant for flow through said 0* 0* 0 I C *e a slurry, and means for injecting said vessel in a direction of flow slurry feed and surfactant in
33. A mill as set forth a grinding zone in said taining said agitating means fluid under pressure in said counter to the flow of said said vessel. in claim 27 which includes, vessel for receiving and main- including a grinding medium, 1 A V a separation zone spaced from said grinding zone for receiving the valuable mineral constituent liberated from said slurry feed in said grinding zone, and a refuse zone positioned adjacent to said grinding zone for receiving the gangue separated from said valuable con- stituent in said grinding zone.
34. A mill as set forth in claim 33 which includes, said grinding zone, said separation zone, and said refuse zone being vertically aligned in said vessel. A mill as set forth in claim 33 which includes, said grinding zone and said refuse zone being angularly i displaced from said separation zone in said vessel. DATED this 4th day of June, 1992. RABINDER S. DATTA WATERMARK PATENT TRADEMARK ATTORNEYS "THE ATRIUM" 290 BURWOOD ROAD HAWTHORN VIC 3122 AUSTRALIA t et 1