Claims:We Claim:

1.A system[100] for mineral seperation comprising of :

froth flotation unit [102] having feedinlet for feeding slurry including the mineral for separation and means for air bubbling ;
gravity separation unit [104] having means for water circulation thereunder said froth floatation unit;
collecting unit[106] thereunder said gravity separation unit;and
centralized control unit[108] operably connected to said froth floatation unit and said gravity separation unit for sequentially operating said means for air bubbling and said means for water circulation whereby initially separating out from top of said froth floatation minerals which attach to air bubbles in said froth floatation unit followed by further mineral separation involving cross current water circulation in said gravity separation unit for buoyancy force driven separation of minerals with lighter densities from top through said froth floatation unit and drip down of heavier density minerals downwards through said gravity separation unit and down under in said collection unit;

density sensor[134] in said collection unit[106] for controlled discharge of desired heavy density minerals through a bottom discharge outlet[136].

2 . The system[100] for mineral separation as claimed in claim 1 wherein

Said froth flotation unit [102] includes a froth flotation column[110], a feed inlet[112], an air inlet [114], an air compressor [116] and an air circulation tubular ring [118] with a plurality of holes [120], wherein thefeed inlet [112] is provided on the wall towards the top end of the forth flotation column [110], the air inlet [114]is provided on the wall towards the bottom end of the froth flotation column [110] which isconnected with the air circulation tubular ring [118], the air compressor [116] is provided outside the wall of the froth flotation column[110], the air circulation tubular ring [118]is provided in the cavity toward the bottom end of the froth flotation column [110];

said gravity separation unit[104] includes a gravity separation column[122], a water inlet[124], a water pump [126] and a plurality of water circulation pipes [128] with a plurality of holes [130], wherein the bottom end of the froth flotation column [110] is embedded in the top end of the gravity separation column[124], the water inlet [126] is provided on the wall towards the bottom end of the gravity separation column [124] which is connected with the plurality of water circulation pipes [128], the water pump [126] is provided outside the wall of the gravity separation column [124], the plurality of water circulation pipes [128] is provided in the cavity towards the bottom end of the gravity separation column [122];

said collecting unit[106] includes a collecting conical column[132], a density sensor[134], a discharge hole[136] and a discharge valve[138], wherein the bottom end of the gravity separation column [122] is embedded in the top end of the collecting conical column [132], the density sensor [134] is provided on the inner wall of the collecting conical column [132], the discharge valve is provided on the discharge hole [136], the density sensor [134] controls the opening and closing of the discharge valve [138], the discharge hole [136] is provided at the bottom end of the collecting conical column [132]; and

saidcentralized control unit [108] includes a power source [140] and motor [142], the centralized control unit being operatively connected to the froth flotation unit [102], the gravity separation unit [104] and the collecting unit [106].

3. The system[100] for mineral separation as claimed in claim 1 or 2, wherein a collecting tank [144] is arranged at the top on the periphery of the froth flotation column [110].

4. The system[100] for mineral separation as claimed in anyone of the claims 1 to 3, wherein a plurality of water circulation pipes [128] are arranged in the cavity of the gravity separation column [122] either in circular or parallel manner.

5. The system[100] for mineral separation as claimed in anyone of the claims 1 to 4, wherein the mineral separation system operates in continuous mode.

6. A process for mineral separation carried out involving the system as claimed in anyone of claims 1 to 5 comprising:

carrying out combination of froth flotation and gravity separationby sequentially subjecting (i) feed slurry including the mineral for separation in froth floatation unit[102] to air bubblingwhereby initially separating out from top of said froth floatation unit minerals which attach to air bubbles in said froth floatation unit followed by (ii) further mineral separation involving cross current water circulation in a gravity separation unit[104]disposed thereunder said froth floatation unit for buoyancy force driven separation of minerals with lighter densities from top through said froth floatation unit and drip down of heavier density minerals downwards through said gravity separation unit and down under in a collection unit[106];

(iii) controlled discharge of desired heavy density minerals based on measures density involving density sensor[134] in said collection unit[106]through a bottom discharge outlet[136] from said collection unit.

7. The process as claimed in claim 6 wherein a centralized control unit[108] operatively connected to said froth flotation unit[102] air bubbling means and gravity separation unit[104] water circulating means is used for stagewise controlled air bubbling in said froth floatation unit and followed by water circulation in said gravity separation unit for said sequentially carrying out the combination mineral separation.

8. The process for mineral separation combining froth flotation and gravity separation, as claimed in anyone of claims 6 or 7 comprising

starting the centralized control unit [108];

feeding a slurry including minerals and flotation reagent in the cavity of the froth flotation column [110] through the feed inlet [112], wherein the minerals have different densities and surface properties;

bubbling the air in the cavity of the flotation column [110] through the plurality of holes [120] of the air circulation tubular ring [118], wherein the minerals with lighter densities attach to the air bubbles which are carriedto the top end of the froth flotation column [110]where the minerals with lighter densities are removed as froth and the slurry of mineralswith higher densities drips down from the froth flotation column [110] to the gravity separation column [122];

circulating the water in the cavity of the gravity separation column [122]through the plurality of holes [130] of the plurality of water circulation pipes [128]; wherein the crosscurrent of the water creates the buoyancy force on the mineral with lighter densities and push them to the froth flotation column [110] and the slurry of mineral with heavy densities drips down from the gravity separation column [122] to the collecting conical column[132];

sensing the density of the slurry of the heavy minerals by the density sensor[134]; and

opening of the discharge valve[138]for obtaining the slurry of the heavy minerals with required density.

9. The process of mineral separation as claimed in anyone of claims 6 to 8, wherein the minerals with light densities overflows from the top end of the froth flotation column 110 and collects in the collecting tank [144].

Dated this the 28th day of January, 2021
Anjan Sen
Of Anjan Sen & Associates
(Applicant’s Agent)
IN/PA-199
, Description:FORM 2
THE PATENT ACT 1970
(39 OF 1970)
&
The Patent Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

1 TITLE OF THE INVENTION :
A SYSTEM FOR MINERAL SEPARATION AND A PROCESS THEREOF COMBINING FROTH FLOTATION AND GRAVITY SEPARATION.



2 APPLICANT (S)

(i) Name : JSW STEEL LIMITED.

Nationality : An Indian Company incorporated under the Companies Act, 1956.

Address : JSW CENTRE, BANDRA KURLA COMPLEX,
BANDRA(EAST),MUMBAI-400051, MAHARASHTRA,INDIA.


(ii) Name : NATIONAL INSTITUTE OF TECHNOLOGY KARNATAKA,
SURATHKAL.

Nationality : A Central Institution incorporated under the National Institute of Technology Act, 2007;

Address : NH 66, SRINIVAS NAGAR, SURATHKAL, MANGALORE-575025, KARNATAKA, INDIA




3 PREAMBLE TO THE DESCRIPTION

COMPLETE



The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION

The invention belongs to the technical field of mineral processing and beneficiation, and in particular to a system and process of mineral separation by combined froth floating and gravity separation with increased efficiency of separation and selectively sorting minerals with small density diference in separate groups.

BACKGROUND OF THE INVENTION

The process of “froth flotation” and “density separation” is widely applicable in the mineral and coal industries for the beneficiation of minerals. The froth flotation process separates minerals in a liquid pulp based on differences in particle surface properties using flotation reagents. The froth flotation causes the gangue material or valuable minerals to float after separating from the mineral slurry. The density separation causes the separation of light and heavy minerals from the mineral slurry based on density difference.

Conventional flotation device as described in Patent No. US4938865A and US 5,397,001 typically includes a column flotation cell and aeration system for froth generation. The aeration introduced bottom of the cell and selected minerals will be collected as froth product and non-selected particles collected as sink product. A fraction containing the floatable particles overflow from the top of the column and a fraction containing the non-floatable particles is discharged from the bottom of the column by gravity or a pump.

Conventional gravity separation device or hindered settling classifier as described in Patent No. US 6,425,485 typically includes a column cell, feed inlet, and counter-current water system. The mineral slurry fed into the column through a feed inlet in the centre of the column. Due to gravity difference, the heavy density particles settle down to the bottom and lighter density particles float to the top of the column. The lighter density particles collected as overflow and heavy density particles collected as underflow.

The problem associated with the froth flotation of iron ore is that separates silica minerals effectively, but alumina is not separated effectively due to the low zeta potential of alumina minerals. Another issue associated with the froth flotation and density separation is that they suffer from low separation efficiency while handling very fine particles. Due to the limitation of the available system, the present invention thus targets to design and develop a hydro-aero separator that helps in the removal of very fine gangue material from the ore material by efficient separation.

OBJECTS OF THE INVENTION

The basic object of the present invention is directed to provide a system for mineral separation and a process for separation of mineral containing gangue material by using the system which combines both froth flotation and gravity separation techniques.

A still further object of the present invention is directed to system and process for raw material beneficiation for the liberation of minerals such as iron ore, gold, and coal, separation of specific low mass gangue material by a combination of froth flotation and gravity separation where the high mass material is collected in the bottom.

A still further object of the present invention is directed to designing system and process that facilitates the removal of gangue materials such as silica and alumina for separation of the high purity iron.

Another objective of the proposed system and process of the present invention is to increase the efficiency of the froth flotation and gravity separation system by increasing the selectivity of the separation of minerals.

Another object of the invention is to provide improved system and process for sorting minerals even with small density differences into several groups utilizing a combination of froth flotation and gravity separation.

Still another object of the present invention is to provide system and method for separating minerals with small density differences into several groups which is versatile and simple to use and which permits adjustment of the system and the corresponding method which is implemented to intensify the degree of separation of minerals by adjustment of any of several parameters, including the fluid velocity of the froth flotation, by adjusting the depth at which the minerals are introduced into the flotation stream or air velocity of the gravity separation.

A still further object of the present invention is to increase the extraction of minerals by combining froth flotation and gravity separation.

SUMMARY OF THE INVENTION

The basic aspect of the present invention is directed to a system for mineral seperation comprising of :

froth flotation unit having feed inlet for feeding slurry including the mineral for separation and means for air bubbling ;
gravity separation unit having means for water circulation thereunder said froth floatation unit;
collecting unit thereunder said gravity separation unit; and
centralized control unit operably connected to said froth floatation unit and said gravity separation unit for sequentially operating said means for air bubbling and said means for water circulation whereby initially separating out from top of said froth floatation minerals which attach to air bubbles in said froth floatation unit followed by further mineral separation involving cross current water circulation in said gravity separation unit for buoyancy force driven separation of minerals with lighter densities from top through said froth floatation unit and drip down of heavier density minerals downwards through said gravity separation unit and down under in said collection unit;

density sensor in said collection unit for controlled discharge of desired heavy density minerals through a bottom discharge outlet.

A further aspect of the present invention is directed to said system for mineral separation systemcomprising a froth flotation unit , a gravity separation unit , a collecting unit 106, and a centralized control unit, wherein said froth flotation unit includes a froth flotation column , a feed inlet, an air inlet, an air compressor, and an air circulation tubular ring with a plurality of holes. The feed inlet is provided on the wall towards the top end of the forth flotation column . The air inlet is provided on the wall towards the bottom end of the froth flotation column which is connected with the air circulation tubular ring. The air compressor is provided outside the wall of the froth flotation column. The air circulation tubular ring is provided in the cavity toward the bottom end of the froth flotation column. The gravity separation unit includes a gravity separation column, a water inlet, a water pump, and a plurality of water circulation pipes with a plurality of holes. The bottom end of the froth flotation column is embedded in the top end of the gravity separation column. The water inlet is provided on the wall towards the bottom end of the gravity separation column which is connected with the plurality of water circulation pipes. The water pump is provided outside the wall of the gravity separation column. The plurality of water circulation pipes is provided in the cavity towards the bottom end of the gravity separation column . The collecting unit includes a collecting conical column, a density sensor, a discharge hole, and a discharge valve. The bottom end of the gravity separation column is embedded in the top end of the collecting conical column. The density sensor is provided on the inner wall of the collecting conical column . The discharge valve is provided on the discharge hole . The density sensor controls the opening and closing of the discharge valve . The discharge hole is provided at the bottom end of the collecting conical column. The centralized control unit includes a power source and motor , the centralized control unit is connected to the froth flotation unit, the gravity separation unit, and the collecting unit.

There is further provided said system for mineral separation wherein the collecting tank is arranged at the top on the periphery of the froth flotation column .

There is further provided said system for mineral separationwherein the plurality of water circulation pipes are arranged in the cavity of the gravity separation column either a cicular or parallel manner.

There is further provided herein that the system for mineral separation system operates in continuous mode.

A further aspect of the present invention is directed to a process for mineral separation carried out involving the system as described above comprising:

carrying out combination of froth flotation and gravity separation by sequentially subjecting (i) feed slurry including the mineral for separation in froth floatation unit to air bubbling whereby initially separating out from top of said froth floatation unit minerals which attach to air bubbles in said froth floatation unit followed by (ii) further mineral separation involving cross current water circulation in a gravity separation unit disposed thereunder said froth floatation unit for buoyancy force driven separation of minerals with lighter densities from top through said froth floatation unit and drip down of heavier density minerals downwards through said gravity separation unit and down under in a collection unit;

(iii) controlled discharge of desired heavy density minerals based on measures density involving density sensor in said collection unit through a bottom discharge outlet from said collection unit.

A further aspect of the present invention is directed to said process wherein a centralized control unit operatively connected to said froth flotation unit air bubbling means and gravity separation unit water circulating means is used for stagewise controlled air bubbling in said froth floatation unit and followed by water circulation in said gravity separation unit for said sequentially carrying out the combination mineral separation.

In accordance with a further aspect of the present invention, said process of mineral separation combining froth flotation and gravity separation comprises the following steps. Firsly, the centralized control unit is started. Secondly, a slurry including minerals and flotation reagent is fed in the cavity of the froth flotation column through the feed inlet . The minerals have different densities and surface properties. Thirdly, the air is bubbled in the cavity of the flotation column through the plurality of holes of the air circulation tubular ring . The minerals with lighter densities attach to the air bubbles which are carried to the top end of the froth flotation column and are removed as froth. The slurry of minerals with higher densities drips down from the froth flotation column to the gravity separation column . Fourthly, the water is circulated in the cavity of the gravity separation column through the plurality of holes of the plurality of water circulation pipes . The crosscurrent of the water creates the buoyancy force on the minerals with lighter densities and pushes them to the froth flotation column and the slurry of minerals with heavy densities drips down from the gravity separation column to the collecting conical column . Fifthly, the density of the slurry of the heavy minerals is measured by the density sensor. Lastly, discharge valve is opened for obtaining the slurry of the heavy minerals with the required density.

In accordance with the process for mineral separation as per present invention, the minerals with light densities overflow from the top end of the froth flotation column and collect in the collecting tank .

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

BRIEF DESCRIPTION OF THE ACCOMPNAYING DRAWINGS

FIG. 1 illustrates a schematic diagram of mineral separation system combining froth flotation and gravity separation according to the present invention;

FIG. 2 illustrates a process of mineral separation combining froth flotation and gravity separation according to the present invention.

Skilled artisans would appreciate that elements in the figures are illustrated for simplicity and clarity to help to improve understanding of embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS

The accompanying figure together with the detailed description below forms part of the specification and serves to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.

The present invention is now discussed in more detail referring to the drawings that accompany the present application. In the accompanying drawings, like and/or corresponding elements are referred to by like reference numbers.

Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or the like parts.

Before describing in detail embodiments that are in accordance with the invention, it should be observed that the embodiments reside primarily to a mineral separation system and method combining froth flotation and gravity separation, which are used to solve the technical problems of complex structure and low separation efficiency of the existing mineral separation system.

FIG. 1 illustrates a schematic diagram of a system(100) for mineral separation combining froth flotation and gravity separation. The mineral separation system 100 combining froth flotation and gravity separation comprising a froth flotation unit 102, a gravity separation unit 104, a collecting unit 106, and a centralized control unit 108.

The froth flotation unit 102 includes a froth flotation column 110, a feed inlet 112, an air inlet 114, an air compressor 116, and an air circulation tubular ring 118 with a plurality of holes 120. The feed inlet 112 is provided on the wall towards the top end of the forth flotation column 110. The air inlet 114 is provided on the wall towards the bottom end of the froth flotation column 110 which is connected with the air circulation tubular ring 118. The air compressor 116 is provided outside the wall of the froth flotation column 110. The air circulation tubular ring 118 is provided in the cavity toward the bottom end of the froth flotation column 110. A slurry including mineral and flotation reagent is fed in the cavity of the froth flotation column 110 through the feed inlet 112. The minerals have different densities and surface properties. The air is bubbled in the cavity of the flotation column 110 through the plurality of holes 120 of the air circulation tubular ring 118. The minerals with lighter densities attach to the air bubbles which are carried to the top end of the froth flotation column 110 and are removed as froth.

The gravity separation unit 104 includes a gravity separation column 122, a water inlet 124, a water pump 126, and a plurality of water circulation pipes 128 with the plurality of holes 130. The bottom end of the froth flotation column 110 is embedded in the top end of the gravity separation column 124. The water inlet 126 is provided on the wall towards the bottom end of the gravity separation column 124 which is connected with the plurality of water circulation pipes 128. The water pump 126 is provided outside the wall of the gravity separation column 124. The plurality of water circulation pipes 128 is provided in the cavity towards the bottom end of the gravity separation column 122. The plurality of water circulation pipes 128 is arranged in the cavity of the gravity separation column 122 either cicular or parallel manner. The slurry of minerals with higher densities drips down from the froth flotation column 110 to the gravity separation column 122. The water is circulated in the cavity of the gravity separation column 122 through the plurality of holes 130 of the plurality of water circulation pipes 128. The crosscurrent of the water creates the buoyancy force on the mineral with lighter densities and pushes them to the froth flotation column 110 and the slurry of mineral with heavy densities drips down from the gravity separation column 122 to the collecting conical column 132.

The collecting unit 106 includes a collecting conical column 132, a density sensor 134, a discharge hole 136, and a discharge valve 138. The bottom end of the gravity separation column 122 is embedded in the top end of the collecting conical column 132. The density sensor 134 is provided on the inner wall of the collecting conical column 132. The discharge valve is provided on the discharge hole 136. The density sensor 134 controls the opening and closing of the discharge valve 138. The discharge hole 136 is provided at the bottom end of the collecting conical column 132. The density of the slurry of the heavy minerals is measured by the density sensor 134. The discharge valve 138 is opened for obtaining the slurry of the heavy minerals with the required density.

The centralized control unit 108 includes a power source 140 and motor 142, the centralized control unit is connected to the froth flotation unit 102, the gravity separation unit 104, and the collecting unit 106. The centralized control unit 108 is started to circulate air and water in the mineral separation system 100.

The collecting tank 144 is arranged at the top on the periphery of the froth flotation column 110.

The mineral separation system 100 operates in continuous mode.

Fig. 2 illustrates a flow chart of a process 200 of mineral separation combining froth flotation and gravity separation using the mineral separation system 100. The process for mineral separation comprises the following steps. In step 202, the centralized control unit 108 is started.

In step 204, a slurry including mineral and flotation reagent is fed in the cavity of the froth flotation column 110 through the feed inlet 112. The minerals have different densities and surface properties.

In step 206, the air is bubbled in the cavity of the flotation column 110 through the plurality of holes 120 of the air circulation tubular ring 118. The minerals with lighter densities attach to the air bubbles which are carried to the top end of the froth flotation column 110 and are removed as froth. The slurry of minerals with higher densities drips down from the froth flotation column 110 to the gravity separation column 122.

In step 208, the water is circulated in the cavity of the gravity separation column 122 through the plurality of holes 130 of the plurality of water circulation pipes 128. The crosscurrent of the water creates the buoyancy force on the mineral with lighter densities and pushes them to the froth flotation column 110 and the slurry of mineral with heavy densities drips down from the gravity separation column 122 to the collecting conical column 132.

In step 210, the density of the slurry of the heavy minerals is measured by the density sensor 134.

Lastly in step 212, the discharge valve 138 is opened for obtaining the slurry of the heavy minerals with the required density.

The minerals with light densities overflow from the top end of the froth flotation column 110 and collects in the collecting tank 144.

The froth flotation column 110 consisting of an external thread connected to the internal thread of the gravity separation column 122. The external thread of the gravity separation column 122 is connected to the internal thread of the collecting conical column 132. The froth flotation column 110, gravity separation column 122, and the collecting conical column 132 can be attached and detached with ease. This provides the flexibility in attaching the different size columns as required for the separation of different materials such as iron, coal, and gold.

Application

Use of Mineral Separation system 100 for iron ore separation:

A process for iron ore separation combining froth flotation and gravity separation using the mineral separation system100 is disclosed. The iron ore comprises iron, silica, and alumina. These have different densities and surface properties. The process for iron ore separation comprises the following steps.

Firstly, the centralized control unit 108 is started.

Secondly, slurry including iron ore and flotation reagents such as depressant, collector and frother is fed in the cavity of the froth flotation column 110 through the feed inlet 112.

Thirdly, the air is bubbled in the cavity of the flotation column 110 through the plurality of holes 120 of the air circulation tubular ring 118. Silica has a lighter density as compared to iron. Hence, the silica attaches to the air bubbles which are carried to the top end of the froth flotation column 110 and are removed as froth. The slurry of iron and alumina with higher densities drips down from the froth flotation column 110 to the gravity separation column 122.

Fourthly, the water is circulated in the cavity of the gravity separation column 122 through the plurality of holes 130 of the plurality of water circulation pipes 128. The cross current of the water creates the buoyancy force on the alumina which has a lighter density than iron. The buoyancy force pushes the alumina to the froth flotation column 110 and the slurry of iron with heavy densities drips down from the gravity separation column 122 to the collecting conical column 132.

Fifthly, the density of the slurry of the iron is measured by the density sensor 134.

Sixthly, discharge valve 138 is opened for obtaining the slurry of the iron with required density.

The silica and alumina with light densities overflow from top end of the froth flotation column 110 and collects in the collecting tank 144.

In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or composition that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article or composition. An element proceeded by "comprises...a" does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or composition that comprises the element.

In the present specification, when a part “includes” a certain component, it means that the component may further include other components, not to exclude other components, unless specifically stated otherwise.

Although not defined differently, all terms including technical terms and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present invention pertains. Commonly used dictionary-defined terms are additionally interpreted as having meanings consistent with related technical documents and currently disclosed content and are not interpreted as ideal or very formal meanings unless defined.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art to which the present invention pertains can easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

The advantages and features of the present invention and methods for achieving them will be clarified with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms, and only the embodiments allow the disclosure of the present invention to be complete, and are conventional in the art to which the present invention pertains. It is provided to fully inform the knowledgeable person of the scope of the invention, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same components throughout the specification.

Thus, in some embodiments, well-known techniques are not specifically described to avoid obscuring the present invention. Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used as meanings commonly understood by those skilled in the art to which the present invention pertains.