Claims:We Claim:

1. System for material beneficiation including :
size based classification aiding hydro-squeeze classifier comprising atleast one hydro squeeze chamber having an inlet for feeding variable sized ground product for desired classification ,atleast one movable squeezing piston carrying atleast a sieve member in said atleast one hydro squeeze chamber , said sieve member enabling separation of selective undersized size material fraction under squeezing action of the said piston in said hydro squeeze chamber.

2.System for material beneficiation as claimed in claim 1 wherein said hydro-squeeze classifier comprises plurality of said hydro squeeze chambers including respective movable pistons and selective sieve member apertures for classification of different sized fractions for desired end uses.

3.System for material beneficiation as claimed in anyone of claims 1 or 2 comprising

said size based classification aiding hydro-squeeze classifier having said plurality of hydro squeeze chamber in operative connection with grinding ball mill for aiding size based further separation of ground products with narrow size distribution ranges.

4.System for material beneficiation as claimed in anyone of claims 1 to 3 comprising a rotary drum grinding ball mill having an inlet trunnion and an outlet trunnion with said outlet trunnion operatively connected to said size based classification aiding hydro squeeze classifier including one or more said hydro squeeze chambers each said chamber having a movable piston assembly having a head including a disc with cooperative said sieve aperture such that motion of the movable piston assembly generate compression pressure leading to narrow size classification of ground materials entering from said rotary drum grinding ball mill.

5.System for material beneficiation as claimed in anyone of claims 1 to 4 wherein said grinding ball mill comprises said inlet trunnion for feeding material into a main cylindrical grinding body portion and an extended discharge end outlet trunnion which is operatively connected to said hydro squeezing classifier,

said hydro squeezing classifier comprising a movable slip in cap for opening and closing the operative connection of said discharge end outlet trunnion of said ball mill with said hydro squeezing classifier for selectively allowing the feeding variable sized ground product for desired classification , plurality of movable piston based classifier discs including selective sieve members based on the different size fractions to be separated /classified, said movable piston based classifier discs providing virtual said hydro squeeze chambers for collecting different sized materials from respective chambers.

6.System for material beneficiation as claimed in anyone of claims 1 to 5 wherein said hydro squeeze chambers include movable slip in cap on a support member for opening and closing the operative connection of said discharge end outlet trunnion of said ball mill with said hydro squeeze chambers and said plurality of pistons are operative connected to respective tubular supports for independent operation and said tubular supports arranged in telescopic manner coaxially, said movable slip in cap movement support member is independently operable while the telescopically disposed tubular supports of the pistons are also independently operable to provide virtual said hydro squeeze chambers for separation of different sized materials.

7. System for material beneficiation as claimed in anyone of claims 1 to 5 wherein said hydro squeezing classifier comprises:

Shell with matching diameter to that of the mill, slip in cap piston and cap rod assembly, plurality of cooperative movable for said squeezing action sieve disc carrying piston heads and corresponding threaded rod assembly depending upon size fractions to be separated/classified ,each said pistons including said classifier sieve providing virtual chambers for collecting different sized material;
means for facilitating rotation and positioning of the piston , the thread over the piston rod including trapezoidal metric thread with thread angle at 30 degree. as per ASTM/BIS standards.

7. System for material beneficiation as claimed in anyone of claims 1 to 6 wherein said grinding mill overflow discharge end trunionhave an extended outlet diameter preferably extended between 0.25D to 2D of the outlet diameter ( D), both said inlet and outlet trunnion, having tapered appearance, the inlet feed trunnionbeing steeped with higher angular position of 15 to 20 degree with respect to discharge end overflow trunnion, to restrict the backward flow and maintain better hindered settling and enhanced initial acceleration to material flow in pulp, a diaphragm spaced axially from said inlet trunnion to provide a pulp containment zone open at its radially outer edge for the ingress of pulp from the drum, the diaphragm having a plurality of lifter whose base angle can be varied from 30 to 45 degree and subsequently form ribs which divide the end zone into a plurality of adjacent zone segments, the outlet overflow discharge end trunnion of the pulp containment zone defining a pulp classifier wherein pulp is differentially separated in accordance with the relative fineness thereof and this section consist liner or lifter arrangement in pattern of reverse helical structure which restrict the forward movement of unground particle and media through the extended end.

8. System for material beneficiation as claimed in anyone of claims 1 to 7 wherein said rotary grinding mill include roller arrangement with cooperative PLC based drive for rotary motion to roller from 12 rpm to 28 rpm with retention time of minerals in the mill on said critical speed varying from 3 minute to 10 minutes depending on the nature of ore including soft to hard ore and pulp density or percentage solid (50 to 80% solid content) of feed material.

9. System for material beneficiation as claimed in anyone of claims 1 to 8 comprising slip-in cap and rod assembly adapted to control the inlet flow of ground material from the grinding mill to the hydrosqueezing classifier and also to block the material backflow into the ball mill during squeezing operations.

10. System for material beneficiation as claimed in anyone of claims 1 to 9 comprising said movable piston adapted to compress the material in the chamber during its forward motion and squeezing and separation of under size material through the sieve aperture to the next chamber, the compression pressure varying from 1.1 bar to 3 bar which enhances the separation proportional to the compressive pressure, preferably with the squeeze pistons having similar disc and screw rod assembly and function similar to a primary piston.

11. System for material beneficiation as claimed in anyone of claims 1 to 10 wherein sievesare fitted on the squeeze piston discs positioned initially in top section with arc angle preferably about 60 degree, and varying from 30 to 90 degree as per requirement of certainty in through put, the base clearance of sieve section from bottom section of disc varying from 10 mm to 30 mm whereas from centre section of disc is the same varying from 30 to 60 mm with inner and outer radial periphery of sieve area varying as per arc angle and clearance provided.

12. System for material beneficiation as claimed in anyone of claims 1 to 11 comprising of a top primary piston disc having coarser size aperture of about 150 micron to 125 micron,whereas the sieve fitted on other piston discs having finer aperture opening from about 100 micron to 45 micron .

13.System for material beneficiation as claimed in anyone of claims 1 to 12 which is free of hydro cyclones for size classification of ground product.

14. A method for raw material beneficiation involving the system as claimed in anyone of claims 1 to 13 comprising:

involving a cooperative size based classification aiding hydro-squeeze classifier in operative communication with a ball mill generating the variable sized ground material comprising atleast one hydro squeeze chamber having an inlet for feeding variable sized ground product for desired classification,atleast one movable squeezing piston carrying atleast a sieve aperture in said atleast one hydro squeeze chamber wherein

ground material to be size based classified is fed into said hydro-squeeze classifier from a discharge end outlet of said ball mill through a movable slip in cap on a support member for opening and closing the operative connection of said discharge end outlet trunnion of said ball mill and after entering the desired quantity of the variable sized product to be classified closing the said discharge end outlet to have the same in said hydro squeeze chamber ;
said hydro squeeze chambers having said plurality of pistons carrying respective sieve member wherein based on the desired size separation/classification the selective piston carrying sieve is independently operated to provide virtual said hydro squeeze chambers for separation of selective sized materials through respective sieve members to be collected in a subsequent undersize collector for desired end purposes.

15.A method as claimed in claim 14 wherein

the hydro squeeze classifier comprises a shell with matching diameter to that of the mill, the number of pistons with desired sieve member classifier is varied based on the size fractions to be separated/classified as per requirements and wherein the pistons provide virtual chambers for collecting different sized material, said hydro squeeze chambers having flush water and discharge valve provisions for each of the chamber for evacuation of sized material obtained in respective chambers.

16. A method as claimed in anyone of claims 14 or 15 wherein said
slip-in cap and rod assembly is used to control the inlet flow of ground material from the grinding mill to the hydro squeeze chamber and also to block the material backflow into the ball mill during squeezing operations.

17. A method as claimed in anyone of claims 14 to 16 wherein in involving plurality of said pistons carrying respective sieve member , the topmost primary piston head compresses the material in the chamber during its forward motion and helps squeezing and separation of under size material through the sieve aperture to the next chamber, the compression pressure varying from 1.1 bar to 3 bar which enhances the separation proportional to the compressive pressure and wherein all the squeeze pistons have similar disc and screw rod assembly and operated similarly to the primary piston.

18. A method as claimed in anyone of claims 14 to 17 wherein the sieve fitted on the squeeze piston discs is positioned initially in top with a preferred arc angle 60 degree, and it varies from 30 to 90 degree as per requirement of certainty in through put, the base clearance of sieve section from bottom section of disc is varied from 10 mm to 30 mm whereas from centre section of disc it is 30 to 60 mm, the inner and outer radial periphery of sieve area is selectively varied as per arc angle and clearance provided.

19. A method as claimed in anyone of claims 14 to 18 wherein the sieve fitted on the primary piston disc used is for coarser size aperture say 150 micron to 125 micronand whereas the sieve fitted on other piston discs used have fine aperture opening from 100 micron to 45 micron as required.

20. A method as claimed in anyone of claims 14 to 19 which can enable classification in the said cooperative hydro squeeze unit attachment for the ball mill free of any requirement of hydro cyclones for size classification of ground product.

Dated this the 15th day of December, 2018
Anjan Sen
Of Anjen Sen & Associates
(Applicants’ Agent)
IN/PA-199
, Description:FIELD OF THE INVENTION
The present invention broadly relates to a system for raw material beneficiation for liberation of minerals, separation of specific sized material by collecting in different chambers, reduction in ultrafine generation through over grinding, reduction in recirculation load and improve the crushing mill efficiency with respect to productivity and energy consumption such as in ball mills used in mineral beneficiation circuits. More specifically, the present invention relates to a hydro-squeeze classifier assisted grinding ball mill where a narrow particle size distribution of ground product or material can be achieved with constant mill output for various raw material feed.The equipment according to the present invention consist of two major sections, the first section addressed as ball mill is for grinding the ore feed to produce ground product and the second section addressed as hydro-squeeze classification as an attachment retrofitted at the discharge end of first section to classify the ground product and provide narrow size range particle size distribution in the final output. In particular the present advancement relates to a novel hydro-squeeze classifier as an attachment to rotary drum grinding ball mill that facilitate separation of specific size particles consisting of three chambers and squeezing pistons favoring separation of specific size material fraction by selective squeezing of the sized material by use of mesh and applying pressure cyclically. The invention is applicable to all types of wet ball mills used for mineral beneficiation installations, more specifically in relation to installations in the steel industry, namely in particular relation to iron ore beneficiation.

BACKGROUND OF THE INVENTION

The iron ore pellet feed is generated through commutation of ore /ore blends. Different ores have different grindability index which is a function of the ore mineralogy. Most commonly used commutation equipment for ore grinding are ball or rod mills which are configured in either close circuit or open circuit. In general, for generating ore fines product for agglomeration processes, closed circuits wet grinding mill is preferred. In the closed circuit ball mill the ground product from the mill is treated in a hydrocyclone to classify/separate fines material from coarse material in the form of over flow and under flow of the hydrocyclone. The underflow of hydrocyclone product being coarse material is recirculated to grinding mill and overflow hydrocyclone product being fine material is used in agglomeration process. The hydrocyclone cut points can be adjusted to separate defined size fraction of the material in the product. Generally, due to the basic operational constraints of the hydrocyclone, the size distribution of the hydrocyclone product has broad range. This results in over grinding and excess ultra fine generation from the recirculated portion and undesired over size fractions in the final over flow product. The recirculation of the underflow product increases the load on the mill and is a function of the ore type/ore blends resulting in requirements of change in media and mill operation set points reflecting on the mill throughput/efficiency.

Rotary drum grinding ball mills have a very large discharge opening or area and smaller area for incoming feed opening and discharge near the periphery of shell provide faster migration of the fines than the oversize particles. Daniel O- Burkes, HIbbmg, Mmn .U.S Patent Number 5,361,997 dated 8 Nov. 1994 discloses the discharge assembly of grinding mill. The discharge assembly includes a plurality of ring sections forming an assembly covering the mill shell at the discharge end. Each ring section has an outer surface supported on the mill shell and inner surfaces forming a radially extending discharge passageway. Each ring section connects to an adjacent section to form a lapped joint there between and additional radially extending discharge passageways. Each lapped joint seals the mill shell from discharge passageway to prevent the discharge material contained therein from wearing the mill shell.

Elliot B. Fitch et.al Patented Jan. 27, 1959 patent number 2870908 discloses hydro cyclone in closed circuit grinding operations. The grinding circuit in lined with hydro cyclone or classifier apparatus state as the closed circuit grinding mill, where the ground material from the grinding mill involves the regulation of the dilution of feed slurry to a hydro cyclone station, being based on the observation that the feed dilution may be varied over a reasonably wide range as required to adjust the mesh of separation obtainable in a hydro cyclone to that desired. In brief, this invention comprises introducing solids to be classified and liquid into a dilution tank, such as, for example, a pump sump or the like, whereby feed slurry is formed. Slurry is removed from the dilution tank while a desired liquid level in said tank is established and maintained by varying the rate of introduction of liquid into the tank in direct proportion to variations in the rate of removal of the feed slurry. Hydro cyclones will classify at some mesh of separation on almost any pulp or slurry that can be pumped through them. However, there are certain inherent factors involved, Such as size of inlet and outlet openings, energy losses, etc., which impose limitations on the range of classification. Incidentally, this inherent limited range of mesh of separation for a given hydro cyclone is one reason why a hydro cyclone station may comprise a battery of hydro cyclones rather than a single hydro cyclone. The capacity of a hydro cyclone at a given mesh of separation is largely a function of its major diameter and under a given set of conditions a given hydro cyclone, to make a desired mesh of separation, might not be able to handle the flow to a given installation to give the desired mesh of separation. The hydro cyclone have two product overflows which comprises the fine material and 1.5 to 3% of coarser fraction of ground material also, whereas the underflow product consist mostly coarser fraction but due to the cut size fraction some extent of finer material also report to underflow. The underflow fraction material of hydro cyclone recirculated to ball mill again for regrinding as the underflow product is not desirable in general.

JoergBinner, Patent Pub. No.: US 2016/0288135 A1, Albert Süssegger Dated-1998-12-02 Patent No.EP0650763B1 disclosed closed-circuit grinding plant having a pre-classifier and a ball mill. This work relates to a closed-circuit grinding plant for grinding fresh material, having a first device for grinding the fresh material, wherein the first device for grinding the fresh material produces ground material for grinding, a static pre-classifier for pre-classifying the ground material for grinding, having an input opening for the ground material for grinding, having an output opening for a classified-out coarse grit fraction, and having a further output opening for the output of a fine-grain output material, a device for classifying out fine material, having an output opening for the output of a separated-out coarse grain fraction, with subsequent recirculation to the first device for grinding the fresh material, having an output opening for the classified-out fine material, and having at least one input opening, wherein one of the at least one input opening is connected to the output opening for the fine-grain output material of the static pre-classifier, a second device for grinding material for grinding, wherein the second device for grinding material for grinding produces a ground material for grinding. To obtain granular fine material from fresh material provided as coarse material, the fresh material is fed into a device for grinding material for grinding. To achieve a high degree of grinding fineness, it is known for the material for grinding to be circulated in the process of a closed-circuit grinding unit with hydrocyclone plant until, as a result of sufficient commutation, it is removed from the circuit by classification as the overflow product.
The disadvantages of the closest analogues are as follows:
As in U.S Patent Number 5,361,997, the discharge end consist plurality of ring section forming an assembly covering the shell to reduce the wear of the shell while in operation. This assembly at discharge end provide elimination of worn media majorly reported after discharge of ground material. But after the discharge end for fully elimination of worn media is still challenge for closed circuit ball mill, these worn media may disturb the operation of classification associated with closed circuit ball mill operation.

As from Patent number 2870908 the hydro cyclone is associated in line as closed circuit with ball mill grinding operation. But the underflow product which are recirculated consist coarser as well as finer fraction also and the variation of recirculation load are in range of 150% to 250% which reduces the throughput of ball mill and can generate more finer fraction in regrinding which are not desirable for downstream process.

The Patent Pub. No. US 2016/0288135 and Patent No.EP0650763B1 is a closest analogue to this invention on processing of ball mill operation, but using a pre-classifier before the grinding ball mill operation itself and is not a cost effective proposition. After the grinding the said patent design consists of a post classifier (hydro cyclone) and the underflow product is again recirculated to ball mill for grinding, hence regrinding of finer material takes place again as discussed in Patent number 2870908.
The prior arts containing with this invention provide a laser focus on best way to design the hydro-squeeze classifier phenomenon along with ball mill grinding unit, which restrict the recirculation of finer ground fraction material to ball mill for further grinding and provide narrow particle size distribution to ground product for downstream process.
The present invention thus targets to design and develop a hydro-squeeze classifier that helps in restricting the recirculation of very fine material to the grinding mill by efficient separation of different sized fine material by squeezing the material through sieves compared to the separation efficiency of hydrocyclone in maintaining narrow size range in the final product.

OBJECTS OF THE INVENTION
The basic object of the present invention is directed to provide a system for material beneficiation involving an equipment of grinding ball mill assisted with hydro-squeeze classifier wherein a narrow particle size distribution of ground product or material can be achieved with constant mill output for various raw material feed.
A further object of the present invention is directed to said equipment comprising a combination of rotary drum grinding ball mill and a hydro-squeeze classifier that helps in restricting the recirculation of very fine material to the grinding mill by efficient stage wise separation of different sized fine material by squeezing the material through sieves.

A still further object of the present invention is directed to said equipment comprising a hydro-squeeze classifier attachment to grinding ball mill which is operated in sync with the ball mill operation to separate particles with specific size ranges.

A still further object of the present invention is directed to said equipment comprising a hydro-squeeze classifier assisted grinding ball millto facilitate separation of specific size particles consisting of three chambers and squeezing pistons favoring separation of specific size material fraction by selective squeezing of the sized material by use of mesh and applying pressure cyclically.

A still further object of the present invention is directed to hydro-squeeze classifier assisted grinding ball mill favour raw material beneficiation for liberation of minerals, separation of specific sized material by collecting in different chambers, reduction in ultrafine generation through over grinding, reduction in recirculation load and improve the crushing mill efficiency with respect to productivity and energy consumption such as ball mills used in mineral beneficiation circuits.

A still further object of the present invention is directed to hydro-squeeze classifier assisted grinding ball mill wherein a unique trunion discharge overflow system of grinding ball mill and an efficient size separation apparatus ( Hydro squeeze classifier) as a sequential attachment to the mill is provided where theHydro squeeze unit is of stationary type and does not put any load on the rotary drum.

Another object of the present invention is directed to hydro-squeeze classifier assisted grinding ball mill suitable for improved grinding and beneficiation of ore material like iron ore, limestone, dolomite etc.

Yet another object of the present invention is directed to hydro-squeeze classifier assisted grinding ball mill wherein said hydro-squeeze classifier comprises hollow drum section where movable pistons and threaded rods assembly are provided to create variable chambers for separation and collection of different narrow sized fine particles.

A still further object of the present invention is directed tohydro-squeeze classifier assisted grinding ball mill whereinthe holding/retention time of the feed in the drum is manipulated by optimizing feed rate and critical speed of rotary drum ball mill anda blend of soft and hard ores can be adopted to maintain constant mill operation ( feed rate and speed) to enhance the throughput performance of the mill.
SUMMARY OF THE INVENTION

The basic aspect of the present invention is directed to provide a system for material beneficiation including :
size based classification aiding hydro-squeeze classifier comprising at least one hydro squeeze chamber having an inlet for feeding variable sized ground product for desired classification ,at least one movable squeezing piston carrying at least a sieve member in said at least one hydro squeeze chamber , said sieve member enabling separation of selective undersized size material fraction under squeezing action of the said piston in said hydro squeeze chamber.

A further aspect of the present invention is directed to saidsystem for material beneficiation wherein said hydro-squeeze classifier comprises plurality of said hydro squeeze chambers including respective movable pistons and selective sieve member apertures for classification of different sized fractions for desired end uses.

A still further aspect of the present invention is directed to saidsystem for material beneficiation comprising

said size based classification aiding hydro-squeeze classifier having said plurality of hydro squeeze chamber in operative connection with grinding ball mill for aiding size based further separation of ground products with narrow size distribution ranges.

A still further aspect of the present invention is directed to saidsystem for material beneficiation comprising a rotary drum grinding ball mill having an inlet trunnion and an outlet trunnion with said outlet trunnion operatively connected to said size based classification aiding hydro squeeze classifier including one or more said hydro squeeze chambers each said chamber having a movable piston assembly having a head including a disc with cooperative said sieve aperture such that motion of the movable piston assembly generate compression pressure leading to narrow size classification of ground materials entering from said rotary drum grinding ball mill.

Another aspect of the present invention is directed to saidSystem for material beneficiation wherein said grinding ball mill comprises said inlet trunnion for feeding material into a main cylindrical grinding body portion and an extended discharge end outlet trunnion which is operatively connected to said hydrosqueezing classifier,

Said hydro squeezing classifier comprising a movable slip in cap for opening and closing the operative connection of said discharge end outlet trunnion of said ball mill with said hydro squeezing classifier for selectively allowing the feeding variable sized ground product for desired classification , plurality of movable piston based classifier discs including selective sieve members based on the different size fractions to be separated /classified, said movable piston based classifier discs providing virtual said hydro squeeze chambers for collecting different sized materials from respective chambers.

Yet another aspect of the present invention is directed to saidsystem for material beneficiation wherein said hydro squeeze chambers include movable slip in cap on a support member for opening and closing the operative connection of said discharge end outlet trunnion of said ball mill with said hydro squeeze chambers and said plurality of pistons are operative connected to respective tubular supports for independent operation and said tubular supports arranged in telescopic manner coaxially, said movable slip in cap movement support member is independently operable while the telescopically disposed tubular supports of the pistons are also independently operable to provide virtual said hydro squeeze chambers for separation of different sized materials.

A further aspect of the present invention is directed to saidsystem for material beneficiation wherein said hydro squeezing classifier comprises:

shell with matching diameter to that of the mill, slip in cap piston and cap rod assembly, plurality of cooperative movable for said squeezing action sieve disc carrying piston heads and corresponding threaded rod assembly depending upon size fractions to be separated/classified, each said pistons including said classifier sieve providing virtual chambers for collecting different sized material;means for facilitating rotation and positioning of the piston, the thread over the piston rod including trapezoidal metric thread with thread angle at 30 degree as per ASTM/BIS standards.

A still further aspect of the present invention is directed to saidsystem for material beneficiation wherein said grinding mill overflow discharge end trunion have an extended outlet diameter preferably extended between 0.25D to 2D of the outlet diameter ( D), both said inlet and outlet trunnion, having tapered appearance, the inlet feed trunnion being steeped with higher angular position of 15 to 20 degree with respect to discharge end overflow trunnion, to restrict the backward flow and maintain better hindered settling and enhanced initial acceleration to material flow in pulp, a diaphragm spaced axially from said inlet trunnion to provide a pulp containment zone open at its radially outer edge for the ingress of pulp from the drum, the diaphragm having a plurality of lifter whose base angle can be varied from 30 to 45 degree and subsequently form ribs which divide the end zone into a plurality of adjacent zone segments, the outlet overflow discharge end trunnion of the pulp containment zone defining a pulp classifier wherein pulp is differentially separated in accordance with the relative fineness thereof and this section consist liner or lifter arrangement in pattern of reverse helical structure which restrict the forward movement of unground particle and media through the extended end.

A still further aspect of the present invention is directed to saidsystem for material beneficiation wherein said rotary grinding mill include roller arrangement with cooperative PLC based drive for rotary motion to roller from 12 rpm to 28 rpm with retention time of minerals in the mill on said critical speed varying from 3 minute to 10 minutes depending on the nature of ore including soft to hard ore and pulp density or percentage solid (50 to 80% solid content) of feed material.

A still further aspect of the present invention is directed to saidsystem for material beneficiation comprisingslip-in cap and rod assembly adapted to control the inlet flow of ground material from the grinding mill to the hydrosqueezing classifier and also to block the material backflow into the ball mill during squeezing operations.

A still further aspect of the present invention is directed to saidsystem for material beneficiation comprising said movable piston adapted to compress the material in the chamber during its forward motion and squeezing and separation of under size material through the sieve aperture to the next chamber, the compression pressure varying from 1.1 bar to 3 bar which enhances the separation proportional to the compressive pressure, preferably with the squeeze pistons having similar disc and screw rod assembly and function similar to a primary piston.

A still further aspect of the present invention is directed to saidsystem for material beneficiation wherein sieves are fitted on the squeeze piston discs positioned initially in top section with arc angle preferably about 60 degree, and varying from 30 to 90 degree as per requirement of certainty in through put, the base clearance of sieve section from bottom section of disc varying from 10 mm to 30 mm whereas from centre section of disc is the same varying from 30 to 60 mm with inner and outer radial periphery of sieve area varying as per arc angle and clearance provided.

A still further aspect of the present invention is directed to saidsystem for material beneficiation comprising of a top primary piston disc having coarser size aperture of about 150 micron to 125 micron, whereas the sieve fitted on other piston discs having finer aperture opening from about 100 micron to 45 micron .

Yet another aspect of the present invention is directed to saidsystem for material beneficiation which is free ofhydrocyclones for size classification of ground product.

A further aspect of the present invention is directed to amethod for raw material beneficiation involving the system as described above comprising:

involving a cooperative size based classification aiding hydro-squeeze classifier in operative communication with a ball mill generating the variable sized ground material comprising atleast one hydro squeeze chamber having an inlet for feeding variable sized ground product for desired classification,atleast one movable squeezing piston carrying atleast a sieve aperture in said atleast one hydro squeeze chamber wherein

ground material to be size based classified is fed into said hydro-squeeze classifier from a discharge end outlet of said ball mill through a movable slip in cap on a support member for opening and closing the operative connection of said discharge end outlet trunnion of said ball mill and after entering the desired quantity of the variable sized product to be classified closing the said discharge end outlet to have the same in said hydro squeeze chamber ;
said hydro squeeze chambers having said plurality of pistons carrying respective sieve member wherein based on the desired size separation/classification the selective piston carrying sieve is independently operated to provide virtual said hydro squeeze chambers for separation of selective sized materials through respective sieve members to be collected in a subsequent undersize collector for desired end purposes.

A still further aspect of the present invention is directed to saidmethod wherein
the hydro squeeze classifier comprises a shell with matching diameter to that of the mill, the number of pistons with desired sieve member classifier is varied based on the size fractions to be separated/classified as per requirements and wherein the pistons provide virtual chambers for collecting different sized material, said hydro squeeze chambers having flush water and discharge valve provisions for each of the chamber for evacuation of sized material obtained in respective chambers.

A still further aspect of the present invention is directed to saidmethod wherein said
slip-in cap and rod assembly is used to control the inlet flow of ground material from the grinding mill to the hydro squeeze chamber and also to block the material backflow into the ball mill during squeezing operations.

A still further aspect of the present invention is directed to saidmethod wherein in involving plurality of said pistons carrying respective sieve member , the topmost primary piston head compresses the material in the chamber during its forward motion and helps squeezing and separation of under size material through the sieve aperture to the next chamber, the compression pressure varying from 1.1 bar to 3 bar which enhances the separation proportional to the compressive pressure and wherein all the squeeze pistons have similar disc and screw rod assembly and operated similarly to the primary piston.
Another aspect of the present invention is directed to said method wherein the sieve fitted on the squeeze piston discs is positioned initially in top with a preferred arc angle 60 degree, and it varies from 30 to 90 degree as per requirement of certainty in through put, the base clearance of sieve section from bottom section of disc is varied from 10 mm to 30 mm whereas from centre section of disc it is 30 to 60 mm, the inner and outer radial periphery of sieve area is selectively varied as per arc angle and clearance provided.

Yet another aspect of the present invention is directed to said method wherein the sieve fitted on the primary piston disc used is for coarser size aperture say 150 micron to 125 micron and whereas the sieve fitted on other piston discs used have fine aperture opening from 100 micron to 45 micron as required

A still further aspect of the present invention is directed to said method which can enable classification in the said cooperative hydro squeeze unit attachment for the ball mill free of any requirement of hydro cyclones for size classification of ground product.

The above and other objects and advantages of the present invention are described hereunder in greater details with reference to the following accompanying non limiting illustrative drawings.

BRIEF DESCRIPTION OF THE ACCOMPNAYING DRAWINGS
Figure 1- Prototype rotary drum grinding ball mill assisted with hydro-squeeze classifier equipment.
Figure2- Different assembly parts design of rotary drum grinding ball mill assisted with hydro-squeeze classifier
Figure3- Lifter and liner assembly of Rotary drum grinding ball mill trunnion.
Figure4- Overflow extended discharge end trunnion
Figure5- flange arrangement for primary disc of primary piston threaded rod assembly.
Figure6- flange arrangement for secondary disc of secondary piston threaded rod assembly.
Figure 7- primary disc front and side view.
Figure 8- secondary disc of secondary piston rod assembly
Figure 9- screw rods for primary andsecondary piston threaded rod assembly

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS

The present invention is directed to providea system for material beneficiation involving hydro-squeeze classifier assisted rotary drum grinding ball mill having modified discharge of ball mill and hydro squeeze attachment to the grinding unit which can produce a final product with narrow particle size distribution. The new designed unit helps in recirculation of coarser size fraction material only and reduces the recirculation load on the mill.

This invention consist of two major sections, the first section addressed as ball mill is for grinding the ore feed to produce ground product and the second section addressed as hydro-squeeze classification as an attachment retrofitted at the discharge end of first section to classify the ground product and provide narrow size range particle size distribution in the final output. The design of first section “rotary drum grinding ball mill” involves modified designing of inlet and discharge outlet trunnions. The angle of tangential plane for both the inlet and discharge trunnion are designed to facilitate continuous flowability of ore material from inlet trunnion and ground material through outlet or discharge trunnion to avoid/suppress the hindered settling phenomena at any acceptable range of solid and water content (50 to 80% solid content) inside the mill. The modifications in the inlet and outlet trunnion helps to improve the unbalanced movement of the material even at high and low mill speed typically in a range of 10 to 40 revolutions per minute (rpm).

The second section which is the hydro-squeeze classification unit is cotter jointed with discharge trunnion, the joint is pined through split key and pin. The hydro-squeeze classification unit consists of multiple chambers to separate out different set size particulate material. While the present design depicts a 3 chamber system, it can have more number of chambers for any selected size classification requirements. The chambers in the hydro squeeze unit are virtual and variable in volume and are created by the movable squeeze pistons. The number of chambers can be increased or decreased by manipulating the squeeze piston assembly. The positional displacement of the squeeze pistons is variable. The positional displacement of the first squeeze piston is defined by the volume to be collected from the mill outlet to the first chamber. The subsequent displacement of the pistons is defined by the calculated material volumes of selected size to be collected and separated. The feeding of ground material to the hydro squeeze unit is controlled through a cap piston assembly operated in sync with Hydro squeeze unit operations.

Each of the squeeze pistons have two sections, one a solid portion and second portion fitted with sieve of selected size for material separation. The sieve to solid portion of the piston is 20:80 % of the piston area. Generally the sieve section of the piston is positioned towards the top facilitating collection and retention of the material in the chamber. The sieve section is positioned towards the bottom during the squeezing operations to facilitate passing of undersize material to the subsequent chambers. The positioning of the sieve section on the piston is achieved by rotating the piston by 180 deg. Each of the chamber section is provided with a drain valve at the bottom to evacuate the chamber and a water flush valve to flush and clean the chamber with water during evacuation.

Generally, the first squeeze piston (closest to discharge trunion) is fitted with defined coarser size sieve to facilitate the oversized material for recirculation to the grinding mill for further commutation. The undersize material from first chamber is squeezed and let into the second chamber. The subsequent pistons starting from second are fitted with sieves for separation of desired size range particles which facilitate separation of particles in different size fractions as selected. All the pistons in the hydro-squeeze classifier unit are movable with to and fro whitworth motion for which the piston assembly is fitted with threaded rod arrangement. The volume of each chamber is variable and is a function of relative axial piston position which can be adjusted in the range of 50 – 350 mm. At the minimum piston position of 50 mm maximum compression pressure upto 3 bar and at maximum piston position 1bar pressure can be achieved. The whitworth movement mechanism through piston and threaded rod arrangement provide high compression pressure on the material and facilitate good separation efficiency of ground material.

Initially all the pistons ( squeeze pistons and Cap piston ) are positioned in their respective parking points. The sieve portion/section of the squeeze pistons is positioned at the top to avoid leakage of water and material to the subsequent chambers. The rotational speed of grinding/ball mill is set according to the type of feed iron ore material and it’sgrindability index. The parking position of the cap piston being open and retracted from discharge end of the mill, the ground output from the mill fills into the first chamber. The flow of material from the mill continues till the level of material in the first chamber equals to the bottom of the discharge trunnion. At this position, the cap piston is moved forward to close the inflow of material to first chamber.

The fist squeeze piston is then moved forward towards the cap piston. The sieve section of the piston is positioned at the bottom of the piston by rotating the piston by 180 deg. The positioning of the sieve section can be achieved by rotating the piston first and move forward for squeezing or rotate during the forward motion. The first squeeze piston fitted with coarser sieve, say + 150 micron aperture size, separates the + 150 and -150 micron particles during the squeezing operation. The piston is moved slowly from it’s parking position to so as to gradually increase the squeeze pressure, maximum being 3bar pressure in the chamber. During the squeezing operation the – 150 micron particles pass to the second chamber while the + 150 micron particles are retained in the first chamber. During the squeezing operation the water in the first chamber is mostly drained to the second chamber and hence requires flushing of the material for drainage. Once the squeezing operation of the first chamber is completed, the bottom drain valve is opened, top water flush valve opened and the material is drained out of the chamber and is recirculated to the mill for further grinding.

Once the first chamber is flushed and drained, the sieve section of the piston is positioned to the top and both the cap piston and the first piston are retreated to their parking positions to facilitate filling of fresh mill output material into the first chamber.

The retrieving motion of the first piston towards the parking position and the squeezing motion of the second piston (forward motion) are synchronized to achieve minimum operation time for classification of material. The sieve position on the second piston is rotated downwards during the squeezing operation. The end of the squeezing operation is defined by the pressure developed in the chamber ( upto 3 bar) to ensure complete separation of desired minus size fractions as per the selected sieve size. The finer size fractions of the material is filled in the third/subsequent chambers for further separation/ squeezing steps. After each of the squeezing operation steps, the chamber is flushed to collected the material and stored separately for blending as per downstream process requirements. The operational sequence of the pistons in subsequent chambers is synchronised with that of second chamber and is similar for all chambers.

The squeezing operation can be controlled through a logic controller to achieve maximum efficiency and optimization of through put.

The present invention overcomes the deficiencies of the prior art by providing solutions in the form of a unique trunnion discharge overflow system and an efficient size separation apparatus ( Hydro squeeze classifier) as a sequential attachment to the mill. The Hydro squeeze unit is of stationary type and does not put any load on the rotary drum.

It is a general aspect of the present invention to provide improved grinding apparatus for grinding ore material like iron ore, limestone, dolomite etc.

It is a also an aspect of the present invention to provide improved grinding apparatus having a special design of inlet feed and discharge end overflow type trunnion. Material flows through the trunnion as a result of the pulp gradient between the feed and discharge openings. The inlet feed trunion section is steeped with higher angular position of 15 to 20 degree with respect to discharge end overflow trunnion, this steeped restrict the backward flow and maintain better hindered settling and enhanced initial acceleration to material flow in pulp. Reverse double helixes in the discharge end trunnion liner retains balls (grinding media) in the mill majorly and discharge the pulp only to the hydro-squeeze classifier section through extended section of discharge end overflow trunnion. This modified discharge helps in retention of the worn grinding media in the mill only.

An additional object of the present invention is to provide improved classification/separation of finer material in the ball mill output through an attachment which is fitted with overflow extended discharge end trunnion termed as hydro-squeeze classification unit. The drum shell design of said hydro-squeeze classifier is similar to rotary drum grinding ball mill shell design, matching the overall volume of hydro-squeeze classifier unit to that of rotary ball mill to maintain a consistent feed rate and through put from grinding and classification operation.

The present invention is directed to provide improved or narrow particle size distribution of ground material through more efficient hydro-squeeze classifier. The said hydro-squeeze classifier consists of hollow drum section where movable pistons and threaded rods assembly and create variable chambers for separation and collection of different narrow sized fine particles. The pistons consist of a disc head fitted with sieve section over 20-25 % of it’s area and the balance is of solid portion. The piston disc on it’s diameter is fitted with flexible nylon ring to facilitate smooth to and fro motion of the piston while providing leak protection of material from one chamber to the other.

In said hydro-squeeze classifier is the design of threaded primary rod which is attached with piston and forms the assembly. The screw or thread over the rod consists of trapezoidal metric thread with thread angle 30 degree. The nominal diameter of said trapezoidal metric threaded piston rod can be varied from 14 mm to 90mm as per the weight of disc attached to the piston. The pitch of said thread also varies as per standard of trapezoidal metric thread from 4 to 12 mm and lead is same if single start mechanism is established. For double start or triple start trapezoidal metric thread lead will be in multiples of number of start and pitch length. This assembly helps to squeeze out material by compression through the sieve section by moving the piston axially in whitworth motion.

In the further aspects of this invention the secondary threaded rod is also attached to the piston. The screw or thread over the secondary rod also consist the trapezoidal metric thread form with thread angle 30 degree. The nominal metric diameter is of said trapezoidal metric thread can be varried from 14 mm to 44mm as per the weight of disc attached to the piston. The pitch of said thread also varies from 4 to 8 mm. This screwed or threaded secondary rod has a function to rotate the piston and piston disc radially. Initially the sieve section on the disc of piston is located at the top and is adjusted towards the bottom during squeezing operations. While movement of secondary rod helps in positioning of the sieve section to top or bottom, the movement of primary rod assembly in axial direction exerts compression load on the material slurry due to which the finer material is allowed to pass through the sieve and collect in the subsequent chamber area. When the compression and sieving of material is completed, the sieve section on the disc is rotated to the top and the solid section to the bottom. This positioning of the sieve and solid sections of the disc appropriately restricts the backflow of material during the subsequent squeezing operations in other chambers.

Each piston rod assembly in the hydro squeeze unit is fitted with a secondary rod assembly to facilitate rotation of the disc independent of the primary rod assembly.

The other important object of this invention is creation of variable compartments/chambers for separation and collection of fine product material with narrow particle size range by the pistons. The number of chambers/compartments that can be created can be manipulated by providing the number of pistons fitted with sieve sections of required size. The chamber volumes can also be varied by manipulation of the number of pistons to be fitted and the distance of whitworth motion as a function of mill output, size ranges to be separated /classified.

Yet another important object of the present invention in the hydro-squeeze classifier unit is the provision of slip-in cap piston system. The said slip-in cap piston system consists of a cap disc and rod assembly, the said slip-in cap disc system is positioned at inlet section of hydro-squeeze classifier. The slip in cap piston is useful in controlling the flow of ground material through overflow discharge of the ball mill to the hydro-squeeze classifier. Initially the cap piston is positioned in the parking position and allows the material collection in the first chamber. When the level of slurry in the first chamber equals to that of the mill the flow of further material from mill to hydro squeeze classifier ceases. At this point of time, the slip-in cap disc/piston is operated through it’s screw rod assembly to close the outlet of ball mill overflow discharge trunnion. The operational time between the opening and closing of the cap piston varies between 30 second to 2 minute depending on the feed rate and type of ore treated and the fineness desired. The said closing through slip-in cap system also serves an important function of restricting the material backflow towards the ball mill grinding section during squeezing operation of the first chamber and consequently helps in development of desired compression pressure.

Another important feature of present invention is provision of a flush valve and drainage valve in each chamber of the hydro squeeze unit. The flush valve and drain valve are positioned centrally for each chamber at the top and bottom of the hydro squeeze unit respectively. Subsequent to the squeezing operation of each chamber by the respective pistons for separation of material size fractions, the material is flushed with water and collected from bottom by operating these valves. The normal position of these valves shall be in closed position only. These valves also serve the purpose of retaining the material in the chamber and maintaining the cleanliness of the chambers.
Yet another important feature of the present invention is the design and provision of static hinged assembly at the connecting end of the discharge of rotary drum grinding ball mill and hydro-squeeze classifier unit. The said static hinged assembly fitted on the inlet portion of the hydro squeeze unit consists of rubber/nylon bottom edges resting on the discharge shell which help in restricting the material leakages from the first chamber of the hydro squeeze unit while maintaining the rotational motion of the ball mill.
The main aspect of present invention is the operation of newly designed hydro-squeeze assisted ball mill to efficiently separate/classify ground product with narrow particle size distribution as required for downstream processes. The first section in the invention consists of rotary ball mill and the second section consists of stationary hydrosqueeze unit. The feed material to the said rotary drum grinding ball mill has 8mm to 1mm particle sizes. In the first aspect of operation the pulp density of feed material should be in the range of 50-80% solid content and rest water. The motor drive provided for rotating the mill is operated at rotational speeds between 12- 28 rpm . The belt assembly provided helps in suppressing the vibrations and maintain smooth rotational operations. The media load (grinding ball) and working volume inside rotary drum is a major aspect in achieving grinding efficiencies and accordingly the ratio of media to feed material is maintained in the range of 1 : 1.5 to 1 : 4. The working volume of grinding mill is maintained in the range of 20% to 40% of total mill volume. The retention time of feed material in grinding drum plays a pivotal role in communition( proper size reduction) and generation of fines. The retention time of feed material depends on the nature of ore (i.e soft to hard ore) and in general the soft ores have retention time in the range of 3 to 6 minutes to provide desired size of ground product, whereas the hard ores have retention time 5 to 10 minutes for generating same. The holding/retention time of the feed in the drum is manipulated by optimizing feed rate and critical speed of rotary drum ball mill. A blend of soft and hard ores can be adopted to maintain constant mill operation (feed rate and speed) to enhance the throughput performance of the mill.
Another main aspect of present invention is operation of hydro-squeeze classifier. The hydro-squeeze classifier is further differentiated into different chambers as detailed in different objectives of invention. Initially, all the pistons including the cap piston are positioned in the parking point with the sieve section of the pistons rotated towards the top. The cap piston is in open position and allows the product from the ball mill directly into the first chamber. The inflow of material to the first section ceases when the volume of material in the first chamber equals to that of the mill (30 -40% of total volume). When the inflow of material from the mill drum stops, the slip-in cap disc is moved forward by operating the screw rod assembly to close the inlet opening to the hydro squeeze unit. The hydro squeeze operation on the material in the first chamber by positioning of sieve section to the bottom and forward motion of the first piston while retaining the positions of the remaining pistons. The compression pressure increases with forward motion of the piston facilitating the squeezing of minus size fractions to the second chamber. The forward motion of the first piston can be operated till a minimum distance of 50 mm is maintained between the cap piston and the first piston. The finer size material ( minus fractions for a defined sieve aperture) passes on to the second chamber and the over sized material is retained in the first chamber. On reaching the end piston position in forward direction, the drain valve and flush valve are opened and the chamber is flushed out to evacuate the chamber. The over sized flush material from chamber one is recirculated to the mill for further grinding. On complete evacuation, the cap piston and first squeeze piston are retracted to the parking position to allow filling of the chamber with fresh material from the mill. While retracting the first squeeze piston, the second squeeze piston is moved forward to squeeze out further size fractions into subsequent chambers. The operation of the squeeze pistons is synchronised to achieve operational efficiency and to maintain close size distribution in the product. The separated size fraction material from each of chambers from second onwards can be used directly in downstream process as per requirements. The operational efficiency of the hydrosqueeze unit can be optimized based on mapping of ball mill discharge rate and the ground material pulp density.
Present invention is thus directed to provide a rotary drum ball mill grinding unit assisted with hydro-squeeze classifier, which can generate the narrow particle size distribution with recirculation of relatively coarser size fraction material only. The design of first section “rotary drum grinding ball mill” put a pivotal attention of inlet design and discharge end design. In the similar way, the design of second section “hydro-squeeze classifier” put more attention on piston head and threaded rod assembly with whitworth motion pattern. The piston head contains disc where the sieve is fitted and the assembly motion create proper compression pressure which leads to narrow size classification of ground material of first section.

Accompanying Figure 1 shows schematic portrayal of the Hydro-squeeze classifier assisted grinding ball mill according to present invention. The dimension of each section is mentioned in portrayal itself, as the other dimension like length and diameter ratio, flange fitness, diameter of disc, piston head and threaded rod assembly, slip-in cap and cap rod etc. can be varied as per requirement of operation. As per the detail portrayal of figure 1, it mainly consists of two parts rotary drum ball mill grinding shell 01 and hydro-squeezing classifier shell 02. The grinding shell 01 has bed support 012 which is made of cast steel, whereas the roller 013 is supported over bed 012 which has connection with motor and rotate the ball mill as per their respective mill speed. In the similar way the hydro-squeeze classifier section 02 as accompanying in figure 1 has a bed support 021 which also made of cast steel product and the 022 is hinged support on shell of 02 to restrict offsetting while compression or squeezing process is carried out.

Accompanying Figure 2 shows the design of integrated part 01 and 02 of figure 1. The desired feed material is fed in to the grinding shell 01 through feeder 20, which has connected trapezoidal inlet section 21 addressed as inlet . The feed material flows through section 21 towards the main grinding body which has cylindrical appearance 19. Around 80% of grinding media is placed in the section 21 and most of grinding process like cascading and catracting action also took place in section 21 with volumetric load (grinding media and feed material) of 30 to 40% of total volume of 01. The section 33 represents the extended discharge end outlet of 01, which is riveted or bolted through 21. The section 33 provides the ground feed material to the hydro-squeezing classifier shell 02. The section 02 contains main focus line in design of slip-in cap rod 14, which is made from mild steel and can be made of other similar material which sustain the load 200 Mpa or more. The front end of 14 contains flange 9 made of mild steel material and have a provision for bolting to support the slip-in cap 8. The flange 9 with slip-in cap 8 is welded to one end of the rod 14. The rod 14 is inserted in to pipe 15 made of mild steel to with stand compressive force during squeezing. One end of the pipe 15 is welded to flange 11 and have a provision for bolting to support disc 10. The classifier disc 10 is made of Teflon material which is light weight. Teflon material will also have less friction during to and fro motion inside 2. The pipe 15 is inserted in to pipe 16 made of mild steel to with stand compressive force during squeezing. Also one end of the pipe 16 is welded to flange 13 and have a provision for bolting to support classifier disc 12. The rod 14, pipe15 and pipe 16 are arranged in telescopic manner; where each component can be individually moved. The movement of rod 14 can be controlled by hand only 35 which is used to close discharge end of rotating drum 33. The movement of classifier disc 10 with pipe 15 is controlled by screw rod mechanism. The screw rod mechanism consists of guide rod 23, screw rod 25, brass flange 28, brass bush 29, guide plate 30 and stopper plate 28. The purpose of guide rod 23 to guide or support guide plate 30 while screw rod 25 is to rotate. The one end of guide rod 23 is fitted in hydro-squeezing closing plate 36 and other end is fitted with stopper plate 28. The purpose of screw rod 25 to move the classifier disc one 10 in hydro-squeezing chamber 2. The one end of screw rod is connected in hydro-squeezing closing plate 36 by means of brass bush 29 which helps screw rod 25 free to rotate and the other end of screw rod is connected to brass flange 28. For free movement of screw rod 25, brass flange 28 was used and it is fitted in guide plate 30. The guide plate 30 consists of screw rod 25, brass flange 28 and guide rod 23. The one end of guide plate 30 is connected to pipe 15 which is opposite to classifier disc one 10 connected. The guide plate 30 will transfer rotating movement of screw rod 25 to liner movement of classifier disc one 10 in hydro-squeezing chamber 2. The stopper plate 28 is used to stop the guide plate 30 when it reach extreme end of screw rod 25. The length of pipe 15 is larger than the length of pipe 16. Since pipe 15 is having classifier disc one 10 which is placed in front of classifier disc two 11. The arrangement for liner movement of classifier disc two 12 is similar to classifier disc one 10. The classifier disc two 12 also uses separate screw rod mechanism 31. To prevent bending and for smooth moment of rod 14, pipe 15 and pipe 16 are inserted in to brass flange 7 which is fitted in hydro-squeezing closing plate 36. The one end of hydro-squeezing shell 2 connected to rotating drum 1 and other end is fitted with hydro-squeezing closing plate 36 by using clamp arrangement 18 and 17.

Accompanying Figure 3 shows the lifter and liner assembly of rotary drum grinding ball mill for the section 01 as shown in figure 1. The lifter and liner assembly designed in reverse double helixes shape 216 and 215. The primary helix 215 has bend angle 30 degree whereas the secondary helix 216 has bend angle 35 degree and this structure is supported on 214.The material used for 214,215 and 216 are rubber and it can be made of other material also like PVC, steel plate etc.

Accompanying Figure 4 shows the overflow extended discharge end . The extended end 212 has spiral appearance and fitted to the 02 section of figure 1 and provides static hinged assembly 213 with 01 of figure 1. The section 211 has also hinged connection with double helix pattern 216 to restrict the media flow towards the section 02 of figure 1.

Accompanying Figure 5 shows the flange arrangement for primary disc of primary piston threaded rod assembly. The discharge product from rotating drum 1 will acts as feed to hydro-squeezing shell 2. The feed collected in hydro-squeezing shell 2 consist of different particle size fraction. For separation of selective narrow size fraction particles from hydro-squeezing shell 2 squeezing of collected feed samples is done by classifier discs 10 and 12. The squeezing process is done sequentially first classifier disc one 10 with larger mesh size is moved to separate coarse particles from chamber one 37 to chamber two 38 inside hydro-squeezing shell 2. During this squeezing process more amount of pressure will be acting on disc one 10. Since disc one 10 is made of teflon material during squeezing process there is a chance of bending of disc one 10, to overcome this flange 11 is fitted to classifier disc one 10. This flange 11 will give structural support to classifier disc one 10. The material used for flange 11 is mild steel. The diameter 101 and thickness 111 of the flange 11 is selected based on the dimension of classifier disc one 10. At the centre of the flange 11 a hole 103 is provided for fitting pipe 15.

Accompanying Figure 6 shows the flange arrangement for secondary disc of secondary piston threaded rod assembly. The squeezed particles in second chamber 38 consist of smaller size fraction which is less than mess size of classifier disc 10. The collected particles in chamber 38 further separated by squeezing classifier disc 12 from chamber 38 to chamber 39. The squeezing process is done sequentially after first classifier disc 10 with larger mesh size completes squeezing, later classifier disc two 12 with small mesh size is squeezed to separate coarse particles from fine particles. During this squeezing process more amount of pressure will be acting on disc 12. Since disc 12 is made of Teflon material during squeezing process there is a chance of bending of disc two 12, to overcome this flange 13 is fitted to classifier disc two 12. This flange 13 will give structural support to classifier disc 12. The material used for flange 13 is mild steel. The diameter 121 and thickness 131 of the flange 13 is selected based on the dimension of classifier disc two 12. At the centre of the flange 13 a hole 123 is provided for fitting pipe 16.

Accompanying Figure 7 shows the primary disc front and side view. The selection of suitable material for classifier discs 10 and 12 is very important. To avoid excess weight and apply less amount of force for disc movement 10 and 12 Teflon material is used. The diameter of primary classifier piston head disc 10 selected based on internal diameter of hydro-squeezing shell 2. At the centre periphery of the 10 a groove 119 is provided for rubber sealing. This rubber sealing will avoid transfer for particles from first chamber 37 to second chamber 38. One third of classifier disc one 10 is provided with opening 106 to fit the screen.

Accompanying Figure 8 shows secondary disc of secondary piston rod assembly. The diameter of classifier disc 12 selected based on internal diameter of hydro-squeezing shell 2. At the centre periphery of the classifier disc 12 a grove 122 is provided for rubber sealing. This rubber sealing will avoid transfer for particles from second chamber 38 to third chamber 39. One third of classifier disc 12 is provided with opening 123 to fit the screen. The classifier disc 12 is fitted to flange 13 through nut and bolt arrangement 121. At the centre of disc one end of the pipe 16 is welded to flange 13 and other end of the pipe 16 welded to flat plate 26. The flat plate 26 is placed in between guide plate 30 which is free to rotate inside the guide plate 30. The flat plate 26 also consists a small rod 124 projection on periphery of flat plate which is used to rotate the classifier disc 12 in squeezing shell 2.

Accompanying Figure 9 shows screw rods for primary andsecondary piston threaded rod assembly. For movement of classifier disc 10 and disc 12 inside squeezing shell 2 screw rods of primary 40 and secondary 25 piston threaded rod are used. The length of screw rods 40 and 25 are selected based on stroke length required inside the squeezing shell 2. Also pitch of screw rods are selected based on the disc 10 and 12 distance to move in one revelation of screw rod. The one end 401 of screw rod 40 is connected in hydro-squeezing plate 36 and other end 402 is connected to stopper plate 28. Similarly, one end 251 of screw rod 25 is connected in hydro-squeezing plate 36 and other end 252 is connected to stopper plate 28.

It is thus possible by way of the present invention to provide a system for material beneficiation involving hydrosqueez classifier assisted grinding ball mill wherein plurality of virtual chambers disposed in said hydro squeeze classifier with variable volume defined by movable squeezing pistons having selectively disposed sieve therein and in operative connection with grinding ball mill adapted for aiding size based further separation of ground products with narrow size distribution ranges into finer size fractions as final product for use/application in downstream processes directly without requiring any hydrocyclone.The composite designed unit helps in recirculation of coarser size fraction material only and reduces the recirculation load on the mill.