Claims:We Claim:

1. A beneficiation process for recovery of iron values from ultra fine size slime/wastes comprising:

subjecting the said ultra fine slime/waste to a sequential combination treatment involving classification, gravity separation and magnetic separation for recovery of iron values upto a concentration of 60 to 62% Fe preferably 61% Fe with weight recovery in the range of 20 to 30% preferably 25 %.
2. A beneficiation process for recovery of iron values from ultra fine size slime/wastes as claimed in claim 1 comprising subjecting to :
hydro cyclone as a classification for 1st stage to remove slimes cut point being 6 microns which is having very less iron bearing material and rich in gangue (silica & alumina) content;
Spiral concentrator as a gravity separator at 2nd stage to recover maximum iron bearing material (maximum size fraction); and finally,
High intensity magnetic separator (SLon) in 3rd stage for further recovery of iron bearing materials from the spiral rejects.

3. A beneficiation process for recovery of iron values from ultra fine size slime/wastes as claimed in anyone of claims 1 or 2 comprising following the three stage parameters as hereunder:
Parameter, specification Process Parameters
6 inchHydrocyclone Humprey fine Spiral concentrator SLon HGMS
Vortex Finder diameter 50 to 60 mm preferably 60 mm NA NA
Spigot diameter 20 to 25 mm preferably 25 mm NA NA
Feed rate 12 to 14 m3/hr preferably 13 m3/hr 70 to 80 m3/hr. preferably 75 m3/hr 80 to 90m3/hr preferably 85 m3/hr
Slurry feed density 1.10 to 1.15 gm/cc 1.30 to 1.35 gm/cc 1.25 to 1.3 gm/cc
Feed inlet pressure 1.10 to 1.13 bar NA NA
Wash water NA 55 to 65 m3/hr preferably 60 m3/hr NA
Magnetic Intensity NA NA 8000 to 9000 gauss
Rinse water NA NA 75 to 85 m3/hr preferably 80m3/hr

4. A beneficiation process for recovery of iron values from ultra fine size slime/wastes as claimed in anyone of claims 1 to 3 wherein in hydro cyclone ultra-fine (less than 6 micron size) particle having low iron bearing material were removed as overflow due to its fine nature and low specific gravity,concentrate product obtained from spiral concentrator having 70 to 80% of -10 micron size particles was used as final concentrator as having desired iron bearing minerals and contains more than 61% Fe and the tailings obtained from the spiral concentrator were treated through 3rd stage high gradient magnetic separator (HGMS).

5. A beneficiation process for recovery of iron values from ultra fine size slime/wastes as claimed in anyone of claims 1 to 4 wherein the Feed, Recovery and Product grade obtained
Description Wt,% Fe,% SiO2,% Al2O3,%
Feed 100 40 - 46 10 - 20 9 - 14
Total concentrate 20 - 25 60 – 62.5 5.5 – 7.5 2.5 – 3.5
Tailing 75 - 80 35 – 40 20 – 25 15 – 18

6. A beneficiation process for recovery of iron values from ultra fine size slime/wastes as claimed in anyone of claims 1 to 5 which is adapted to process ultra-fine particles of 70 to 80% of -10 µm size involving said combination of classification, gravity separation and magnetic separation.

7. A beneficiation process for recovery of iron values from ultra fine size slime/wastes as claimed in anyone of claims 1 to 6 wherein up to -6 µm ultra-fine size material are removed by using hydrocyclone as a classification and enables rejection of tails from with lower Fe with the range of 30 to 35% and size less than 10 microns (-10 micron size is 90%).

8. A beneficiation process for recovery of iron values from ultra fine size slime/wastes as claimed in anyone of claims 1 to 7 comprising involving three different tailings having 31 - 47% Fe, 9 - 12% alumina, 10 - 14% silica.

9. A beneficiation process for recovery of iron values from ultra fine size slime/wastes as claimed in anyone of claims 1 to 8 wherein :

said hydro-cyclone at first stage of process the particles less than 6 micron size of ultra-fine material were removed through 6 inch hydro-cyclone with parameters Vortex finder diameter 60mm, Spigot diameter 25mm, Feed rate 13 m3/hr, feed slurry density 1.10 to 1.15 gm/cc and feed inlet pressure 1.10 to 1.13 bar;
said spiral concentrator at second stage enables Fe recovery from ultra-fine tailings blend involving Humphrey 6 turns Spiral concentrator with parameters feed slurry density 1.30 to 1.35 gm/cc, wash water 60 m3/hr, feed rate 75 m3/hr; and

said HGMS at third stage comprise processing of ultra-fine iron ore tails and its blend through SLon (HGMS) with using fine matrix (1 mm) with parameters, feed density 1.25 to 1.30 m/cc, feed rate 85 m3/hr, rinse water 80m3/hr to recover iron bearing minerals.

10. A system for carrying out beneficiation process for recovery of iron values from ultra fine size slime/wastes following the method of claim 1 comprising:
a hydro-cyclone classifier for receiving feed material;
a spiral concentrator for enable gravity separation; and
a high gradient magnetic separator.

Dated this the 9th day of October, 2019
Anjan Sen
Of Anjan Sen & Associates
(Applicants’ Agent)
IN/PA-199

, Description:FIELD OF THE INVENTION

The present invention relates to beneficiation process for recovery of iron values from ultra-fine size slime containing low iron bearing minerals and high gangue minerals.More particularly, the present invention is directed to a process for beneficiation of ultra-fine particles of different process wastes such as slime pond materials, WWP tailing and TBP tailingcontaining42 to 47% Fe, 31 to 35% Fe and 37 to 42% Fe respectively.More specifically, the invention is related to beneficiation of ultra-low grade iron ore tailings of size below 75 microns(~ 70% particles are of less than 10 microns)having alumina and silica more than 12% each to produce enriched iron concentrate with reduced gangue content.In order to recover the maximum iron bearing minerals, a three stage beneficiation process i.e., classification, gravity concentration and magnetic separation has been developed. The upgraded recovered material can be used asfeed in pellet plant.

BACKGROUND OF THE INVENTION

At JSW Steel, 20 MTPA capacity ore beneficiation plant (OBP) processes the medium and low grade iron ores to meet the required quality for pellet and sinter making process. The iron ore of this region is although rich in iron content but suffers from two major disadvantages, i.e., fragileness (low tumbler index) and high silica and alumina which generates large quantity of fines during mining and tails during beneficiation. The discarded tailing contains 42 - 47% Fe, 9 - 12% alumina and 10 - 14% silica.

Recently, the two stage magnetic process has been installed at tailing beneficiation plant (TBP) to further recover the iron values from OBP tailing containing 44 - 48%Fe to enrich Fe more than 61%. Now, the final tailing generated from the TBP contains 37 to 42% Fe, 11 - 15% alumina and 13 - 20% silica which is partly processed in slime recovery plant (SRP) and partly dumped in slime pond. The particle size distributions of all these three samples are shown in Table 1.

Table 1:Particle size distribution of feed samples, wt%

Size, µm
Description -2 -10 -25 -32 -45 -63 -75 -150 +150
Slime pond material 19.58 37.29 48.22 51.39 64.29 69.24 73.15 82.46 17.54
TBP tailings 31.87 72.59 84.85 85.52 86.83 88.37 89.02 100 0
WWP tailing 17.85 56.45 71.13 74.72 80.91 88.08 91.75 99.94 0.06

TBP tailing sample contains higher percentage of ultra-fine particles, i.e., more than 70% of -10 micron size particles and entire sample is less than 75 micron in size. The tailing pond sample contains ~32% of -10 micron size particles which is relatively coarser and can respond to gravity concentration than that of TBP tailing sample. Detailed chemical composition of all three feed samples has been given in Table 2. The TBP tailing sample has low Fe (37 to 42%), high silica (13 to 20%) and high alumina (11 to 15%). Tailing pond sample contains 42 to 47% of Fe, 10 to 14% of silica and 9 to 12% of alumina which is dumped in tailing pond from the iron ore beneficiation plant as reject.

Table 2:Chemical analysis all four samples, wt%

Elements
Specification Fe (Total) SiO2 Al2O3 FeO Carbon
Tailing Pond material 44 - 48 10 - 14 9 - 12 4 - 6 1 - 2
TBP tailings 37 - 41 13 - 20 11 - 15 0 0
WWP tailing 35 - 38 8 -11 5 - 6 0 20 - 25

Earlier, tailing pond sample along with iron ore beneficiation tailings were processed through froth flotation process by using DEC (Dual extraction column). The yield obtained from froth floatation process was around 20 to 35% and iron content in the concentrate was in the range of 56 to 58% Fe which is not suitable for pellet feed. The yield and grade was low as the ultrafine particles do not respond to reagents added into the process as collector and frother. The process flow diagram (flotation process) of slime recovery plant is shown in accompanying Figure 1.

The chemical analysis of feed and product of slime recovery plant is shown in Table 3.

Table 3:Chemical analysis of SRP feed and product

Description Wt,% Fe,% SiO2,% Al2O3,%
Feed 100 45 to 48 12 to 14 10 to 12
Total concentrate 20 to 35 56 to 58 6 to 8 3 to 5
Tailing 65 to 80 42 to 43 14 to 16 12 to 14

The concentrate weight recovery of slime recovery plant with flotation process was at lower side.

Indian Patent Application No. 971/KOL/2014dated1stApril, 2016,disclosed about the beneficiation process of iron ore fines.In this patent he developed a beneficiation process for iron ore fines of size less than 1 mm having 56.16% Fe, 9.02% silica and 6.96% of alumina content. The process comprises dry screening of size 250 micron, two stage hydro cyclone, Fine Mineral Spiral Separator (FMSS) and High Gradient Spiral Separator (HGSS) resulting concentrate with having 61% Fe.

US patent No. 4,192,738, dated 11March’1980 by Colombo et.al. describes the process for scavenging iron from tailings producced by the flotation beneficiation of iron ore. This process includes the step of scavanging the flotation tailings using wet high intensity magnetic separation (WHIMS). There is also disclosed a process for increasing the recovery of iron ore in a flotation beneficiation process. This iron ore recovery process includes the steps of feeding the magnetic concentrate produced by the scavanging process to a flotation system and then carrying out an additional flotataion step.This is not relevant to applicant’s process. This prior patent processed flotation tailing in HGMS.

Chinese patent No. CN103495495B, dated 2nd March, 2016; claims an ultra-poor iron ore beneficiation method, for solving the problem that the existing mine selecting technique capable of ultra-poor iron ore screening. The invention comprises crushing, sieving, grinding treatment, GK screen, high frequency sieve, permanent magnetic separator with high gradient magnetic separator, reselection processing, a tail ore recycling machine screening process. The method can ultra-poor iron ore is screened to produce the qualified iron ore concentrate and screening the tailings to produce the qualified iron ore concentrate and improve the utilization rate of resource.

Indian Patent Application No. IN239834B dated 9thApril, 2009 disclosed that a process has been developed and applied successfully in the Barsua iron ore mines of Orissa to solve its industrial problem Iron ore tailings contain iron concentration around 45%. This research examines the feasibility of the recovery of resources from tailings and focuses on the reduction in tailings volume as part of environmental management strategy. Adopting the process and with the use of Wet High Intensity Magnetic Separator (WHIMS) and it couldbe possible to improve the Fe content in the recovered ore from 45% to 64% and Al2O3 as well as SiO2 can be reduced to 2.20% and 2.75% respectively which can be utilized as resource for iron and steel making with 50% recovery from tailings. Thus a substantial amount, can be recovered as resource, which can be used as a sinter feed for making iron and steel it also reduces the tailing volume as well by adding those additional units to beneficiation plant. Sintering test was done with the recovered ore fines, which are mixed with fresh iron ore sinter feed at different proportions, tested and the optimum proportion (up to 20%) has been evaluated in which there would be no adverse effect on the physical and metallurgical characteristics of the sinter.

Chinese patent/appliction No. CN101850295B, dated 16th Jan, 2013; discloses a beneficiation method for producing high-quality iron ore concentrate by low-grade magnetic iron ore, which comprises the following steps that a stage grinding-stage magnetic separation discarding tailing beneficiation process is adopted to produce magnetic separation ore concentrate with the iron ore concentrate grade TFe of 62-66%.Apositive ion collector reverse flotation process is adopted on the magnetic separation ore concentrate to obtain positive ion collector reverse flotation iron ore concentrate and middling, a negative ion collector reverse flotation process is adopted on the middling obtained by positive ion collector reverse flotation to obtain negative ion collector reverse flotation iron ore concentrate and positive ion collector reverse flotation iron ore concentrate and negative ion collector reverse flotation iron ore concentrate are combined to obtain the ultimate high-quality iron ore concentrate. The inventionprocess is ion reverse flotation followed by magnetic separation process.

There has been thus a need in the existing art to develop a more improved process of treating the tailings/wastes developed in iron ore beneficiation plants(OBP) containing ultra fine iron ore particles in low proportion and large amount of gangue, to recover iron value economically. To further minimise the tailing loss and improve the recovery of iron bearing minerals from OBP- tailings, iron ore tailing pond material and WWP tailing, new beneficiation process have been developed with combination of classification, gravity concentration and magnetic separation process. In present study de-sliming cyclone, Spiral concentrator and SLon (high gradient magnetic separator) was used as a three stage process.

OBJECTS OF THE INVENTION

The basic object of the present invention is directed to provide a process for recovery of iron values from ore beneficiation plant tailings having 31-47% Fe, 9 - 12% alumina and 10 - 14% silica, which is extremely fine in size(~70% particles are of less than 10 microns).

A further object of the present invention is directed to a process for recovery of iron values from ultra-fine size slime containing low iron bearing minerals and high gangue minerals.

Another object of the present invention is directed to provide a process for recovery of iron values from ore beneficiation plant tailings to produce enriched iron concentrate with reduced gangue content.

Yet another object of the present invention is directed to a process to recover the maximum iron bearing minerals from tailings of ore beneficiation plant, wherein a three stage beneficiation process i.e., classification, gravity concentration and magnetic separation has been applied.

A further object of the invention is directed to a process to recover iron bering materials from ore beneficiation plant ultra fine tailings to obtain a product having 60 to 62% Fe with 20 to 25% weight recovery.

A stillfurther object of the present invention is directed to a process for recovery of iron values from ultra-fine size slime wherein the upgraded recovered material can be used as feed in pellet plant.

SUMMARY OF THE INVENTION
The basic aspect of the present invention is directed to a beneficiation process for recovery of iron values from ultra fine size slime/wastes comprising:

subjecting the said ultra fine slime/waste to a sequential combination treatment involving classification, gravity separation and magnetic separation for recovery of iron values upto a concentration of 60 to 62% Fe preferably 61% Fe with weight recovery in the range of 20to 30% preferably 25 %.
A further aspect of the present invention is directed to a beneficiation process for recovery of iron values from ultra fine size slime/wastes comprising subjecting to:
hydro cyclone as a classification for 1st stage to remove slimes cut point being 6 microns which is having very less iron bearing material and rich in gangue (silica & alumina) content;
Spiral concentrator as a gravity separator at 2nd stage to recover maximum iron bearing material (maximum size fraction); and finally,
High intensity magnetic separator (SLon) in 3rd stage for further recovery of iron bearing materials from the spiral rejects.

A still further aspect of the present invention is directed to a beneficiation process for recovery of iron values from ultra fine size slime/wastes comprising following the three stage parameters as hereunder:
Parameter, specification Process Parameters
6 inchHydrocyclone Humprey fine Spiral concentrator SLon HGMS
Vortex Finder diameter 50 to 60 mm preferably 60 mm NA NA
Spigot diameter 20 to 25 mmpreferably 25 mm NA NA
Feed rate 12 to 14 m3/hr preferably 13 m3/hr 70 to 80m3/hr. preferably 75 m3/hr 80 to 90m3/hr preferably 85 m3/hr
Slurry feed density 1.10 to 1.15 gm/cc 1.30 to 1.35 gm/cc 1.25 to 1.3 gm/cc
Feed inlet pressure 1.10 to 1.13 bar NA NA
Wash water NA 55 to 65 m3/hr preferably 60 m3/hr NA
Magnetic Intensity NA NA 8000 to 9000 gauss
Rinse water NA NA 75 to 85 m3/hr preferably 80m3/hr

Another aspect of the present invention is directed to a beneficiation process for recovery of iron values from ultra fine size slime/wastes wherein in hydro cyclone ultra-fine (less than 6 micron size) particle having low iron bearing material were removed as overflow due to its fine nature and low specific gravity,concentrate product obtained from spiral concentrator having 70 to 80% of -10 micron size particles was used as final concentrator as having desired iron bearing minerals and contains more than 61% Fe and the tailings obtained from the spiral concentrator were treated through 3rd stage high gradient magnetic separator (HGMS).

Yet another aspect of the present invention is directed to a beneficiation process for recovery of iron values from ultra fine size slime/wastes wherein the Feed, Recovery and Product grade obtained
Description Wt,% Fe,% SiO2,% Al2O3,%
Feed 100 40 - 46 10 - 20 9 - 14
Total concentrate 20 - 25 60 – 62.5 5.5 – 7.5 2.5 – 3.5
Tailing 75 - 80 35 – 40 20 – 25 15 – 18

A further aspect of the present invention is directed to a beneficiation process for recovery of iron values from ultra fine size slime/wastes which is adapted to process ultra-fine particles of 70 to 80% of -10 µm size involving said combination of classification, gravity separation and magnetic separation.

A still further aspect of the present invention is directed to said beneficiation process for recovery of iron values from ultra fine size slime/wastes whereinup to -6 µm ultra-fine size material are removed by using hydrocyclone as a classification and enables rejection of tails from with lower Fe with the range of 30 to 35% and size less than 10 microns (-10 micron size is 90%).

A still further aspect of the present invention is directed to said beneficiation process for recovery of iron values from ultra fine size slime/wastes comprising involving three different tailings having 31 - 47% Fe, 9 - 12% alumina, 10 - 14% silica.

Another aspect of the present invention is directed to saidbeneficiation process for recovery of iron values from ultra fine size slime/wastes wherein :

said hydro-cyclone at first stage of process the particles less than 6 micron size of ultra-fine material were removed through 6 inch hydro-cyclone with parameters Vortex finder diameter 60mm, Spigot diameter 25mm, Feed rate 13 m3/hr, feed slurry density 1.10 to 1.15 gm/cc and feed inlet pressure 1.10 to 1.13 bar;
said spiral concentrator at second stage enables Fe recovery from ultra-fine tailings blend involving Humphrey 6 turns Spiral concentrator with parameters feed slurry density 1.30 to 1.35 gm/cc, wash water 60 m3/hr, feed rate 75 m3/hr; and

said HGMS at third stage comprise processing of ultra-fine iron ore tails and its blend through SLon (HGMS) with using fine matrix (1 mm) with parameters, feed density 1.25 to 1.30 m/cc, feed rate 85 m3/hr, rinse water 80m3/hr to recover iron bearing minerals.

Yet another aspect of the present invention is directed to a system for carrying out beneficiation process for recovery of iron values from ultra fine size slime/wastes following the method as described above comprising:
a hydro-cyclone classifier for receiving feed material;

a spiral concentrator for enable gravity separation; and

a high gradient magnetic separator.

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

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1: shows theprocess flow diagram for conventional Slime recovery plant using froth flotation process in Dual Extraction Column.
Figure 2: shows the three-stage beneficiation process flow sheet for treating slimes according to present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPNAYING DRAWINGS
The present invention is directed to provide a process for recovery of iron values from ore beneficiation plant tailings having 31-47% Fe, 9 - 12% alumina and 10 - 14% silica, which is extremely fine in size(~70% particles are of less than 10 microns).Three stage beneficiation process involving Hydro cyclone, Spiral concentrator and HGMS, is designed to process ultra-fine particles of 70 to 80% of -10 µm size using combination of classification, gravity separation and magnetic separation.

The iron ore tailing pond material contains 42 to 47% Fe with32 to 37% ultra-fines of -10 µm size. The TBP tails has 37 to 42% Fe content with 70 to 80% ultra-fines -10µm size.TBP tailing containsaround 45 - 50% of hematite, 13 - 18% of goethite and limonite and around 30% of quartz and kaolinite. Slime pond sample contains a little amount of FeO phase and major portions of Hematite and goethite phases. The concentration criterion of the gangue and iron bearing material is above 2.4, the material which is having above 1.8 concentration criterion can be separated through gravity separation technique. To recover the maximum iron bearing minerals from all these tails, a three stage beneficiation process have been developed by using classification, gravity separation and magnetic separation process based on the concentration criterion and characterization. Hydro cyclone was used as a classification for 1st stage to remove slimes (cut point is 6 microns) which is having very less iron bearing material and rich in gangue (silica & alumina) content. Spiral concentrator was used as a gravity separator at 2nd stage to recover maximum iron bearing material (maximum size fraction). High intensity magnetic separator (SLon)was used in 3rd stage for further recovery ofiron bearing materials from the spiral rejects.

A three-stage beneficiation process studies have been carried out using Hydro cyclone, Spiral concentrator and HGMS. Size analysis and chemical analysis of all samples which are used for the experiments are shown in Table 1 and Table 2 respectively. The flow diagram of the process flow is shown in Figure 2. Three samples those are slime pond material, TBP tailing, and WWP tailing was blended 40–60%, 30–50%, and 5– 20%proportionsrespectively and treated in first stage (classification) with using hydrocyclone (6 inch) by maintaining parameterswhich are shown in Table4. Over flow (O/F) material obtained from the first stage hydrocyclone was discarded as final tailing because it contains less iron bearing minerals and rich gangue materials with size range of below 6 microns. The hydrocyclone under flow (U/F) was fed to 2nd stage spiral concentrator by maintaining parameters as shown in Table4.
Table4: All three stage process parameters

Parameter, specification Process Parameters
6 inch Hydrocyclone Humprey fine Spiral concentrator SLon HGMS
Vortex Finder diameter 60 mm NA NA
Spigot diameter 25 mm NA NA
Feed rate 13 m3/hr 75 m3/hr 85 m3/hr
Slurry feed density 1.10 to 1.15 gm/cc 1.30 to 1.35 gm/cc 1.25 to 1.3 gm/cc
Feed inlet pressure 1.10 to 1.13 bar NA NA
Wash water NA 60 m3/hr NA
Magnetic Intensity NA NA 8000 to 9000 gauss
Rinse water NA NA 80m3/hr

Concentrate product obtained from spiral concentrator was considered as final concentrator due to having desired iron bearing minerals and contains more than 61% Fe. The tailings obtained from the spiral concentrator was treated through 3rd stage high gradient magnetic separator(HGMS) which is shown in Figure 2 and recovered maximum iron bearing minerals with maintain magnetic field intensity 9000 Gauss.

In hydro cyclone ultra-fine (less than 6 micron size) particle which is having low iron bearing material was removed as overflow due to its fine nature and low specific gravity. In the process of Humphrey fine Spiral concentrator, heavier iron bearing particles get affected by the centripetal forces due to its high specific gravity and get separated from the lighter particles. All fine lighter particle (alumina and silica) will get effected by the centrifugal force generated in the spiral process will throw the lighter particles into outside of the periphery and get it separated from the heavier. In high gradient magnetic separation process (HGMS) it is possible to capture the ultra-fine iron bearing particles to the maximum extent with using fine matrix (1mm size) due to the magnetic susceptibility of the iron bearing minerals which are present in the feed material. Finally, the product achieved by developed three stage beneficiation process is having 60 to 62.5% of Fe with 20 to 25% of weight recovery.The recovered mag concentration from the HGMS as considered as a final concentrate and non mag material was considered as a final tailing. The recovery and grade of product from the developed three stage beneficiation process is shown in Table 5.
Table 5:Feed, Recovery and Product grade of three-stage beneficiation process developed

Description Wt,% Fe,% SiO2,% Al2O3,%
Feed 100 40 - 46 10 - 20 9 - 14
Total concentrate 20 - 25 60 – 62.5 5.5 – 7.5 2.5 – 3.5
Tailing 75 - 80 35 – 40 20 – 25 15 – 18

It would be apparent from the above description of the new process comprising the following salient features:
i. Three stage beneficiation process is designed to process ultra-fine particles of 70 to 80% of -10 µm size using combination of classification, gravity separation and magnetic separation.
ii. The spiral concentrator is used to recover the iron bearing minerals from ultra-fine size material which is having 70 to 80% of -10 micron size particles.
iii. To recover maximum iron bearing minerals from high alumina and high silica content slimes (tailing), three-stage beneficiation process was developed with using Hydrocyclone, Spiral concentrator and High gradient magnetic separator (SLon).
iv. Up to -6 µm ultra-fine size material are removed by using hydrocyclone as a classification.
v. Through newly developed three stage beneficiation flow sheet, better concentrate grade and good recovery were obtained from the slimes.
vi. Optimized three stage beneficiation process circuit for ultra-fine size material which is having very low grade Fe has been developed.
vii. The rejection of tails from the developed process with lower Fe with the range of 30 to 35% and size less than 10 microns (-10 micron size is 90%)

It is thus possible by way of the present invention to provide a three stage beneficiation process using Spiral concentrator, Hydrocyclone and High gradient magnetic separator (SLon) to recover maximum ultra-fine iron bearing minerals from ultra-fine tailings including from high alumina and high silica content slimes (tailing), wherein the product achieved by said three stage beneficiation process is having 60 to 62.5% of Fe with 20 to 25% of weight recovery. The recovered mag concentration from the HGMS is considered as a final concentrate and non mag material was considered as a final tailing.