Claims:We Claim,

1. An iron ore sintering composition including iron ore fines suitable for blast furnace iron making favouring product/sintered ore yield of (+5mm ) comprising:
40-50% by wt. of iron ore, wherein the iron ore comprises 40-70% of iron ore having particles size <150 µm, remaining iron ore ranging from 60-30 % of total iron ore having particle size in the range of 150 µm to 8 mm; fluxes comprise 2.5-9.0% by wt limestone having particle size of <3.15 mm, 2.5-8.0% by wt. dolomite having particle size of <3 mm, and 1.4-4.2% by wt. calcined lime fines (<1 mm); solid fuel comprises 4-6% by wt. of coke breeze; and 15-45% by wt. sinter return fines having particle size of <5 mm.
2. The iron ore sintering composition as claimed in claim 1, favouring iron ore sinter characteristics including improvement in product/ sintered ore yield (+5mm) in the range of 0.5 to 2.5 % w.r.t the conventional sintering process, tumbler index (+6.3 mm) is >65% and reduction in return fines generation is in the range of 4-13%.

3. The iron ore sintering composition as claimed in anyone of claims 1 or 2, wherein the composition comprising:
Fe % SiO2 % Al2O3 % CaO % MgO % MnO, % LOI %
Iron Ore 62.01 3.01 2.71 0.04 0.04 0.37 3.08
Lime Stone 0.89 2.05 0.47 50.49 2.73 0.00 42.59
Dolomite 0.79 5.22 0.67 29.05 19.49 0.00 43.97
Calcined Lime 0.31 0.81 0.28 93.94 1.49 0.00 3.05
Sinter Return Fines 53.59 6.15 6.15 3.25 11.95 2.12 0.50
Micro Pellets 41.19 6.05 2.32 25.07 3.73 0.25 10.25
Coke breeze Fe, % SiO2, % Al2O3, % CaO, % MgO, % MnO C, %
0.63 7.72 4.43 0.67 0.16 0.00 86.62

4. A process for the manufacture of iron ore sinter including iron ore microfines involving the iron ore sintering composition as claimed in anyone of claims 1 to 3 comprising:
providing the selective iron ore sintering composition comprising 40-50% by wt. of iron ore, wherein the iron ore comprises 40-70% of iron ore having particles size <150 µm, remaining iron ore ranging from 60-30 % of total iron ore having particle size in the range of 150 µm to 8 mm; fluxes comprise 2.5-9.0% by wt limestone having particle size of <3.15 mm, 2.5-8.0% by wt. dolomite having particle size of <3 mm, and 1.4-4.2% by wt. calcined lime fines (<1 mm); solid fuel comprises 4-6% by wt; and 15-45% by wt. sinter return fines having particle size of <5 mm;
adding water to said selective iron ore sintering composition;;
mixing said water and iron ore sintering composition maintaining moisture content in the range of 7.5 to 10.5 % by wt.; and
finally subjecting the mix thus obtained to granulation to obtain the granules for desired production of iron ore sinter favouring desired product/sintered ore yield of (+5mm ).

Dated this the 16th day of June, 2021
Anjan Sen
Of Anjan Sen & Associates
(Applicants’ 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 METHOD OF MANUFACTURING IRON ORE SINTER WITH ENHANCED MICROFINES AND IMPROVED QUALITY AND PRODUCT YIELD.


2 APPLICANT (S)

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.




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 present invention relates to the development of an iron ore sintering process which utilizes increased amount of microfines (less than 150-micron iron ore particles) for producing desired quality of sinter suitable for feed to blast furnace iron making. More particularly, the invention relates to a method to improve the product yield and quality of the iron ore sinter using fines (i.e., less than 150 µm particles).

BACKGROUND OF THE INVENTION
Sinter is a prepared burden that constitutes the major proportion of feed to the blast furnace. Sinter is formed when a certain portion of iron ore is mixed in defined proportions with coke/coal fines and other additives, the mixture is subjected to high temperatures derived from the combustion of coke or coal fines, and it is agglomerated by incipient fusion of the particles of ore to form solid sinter particles having considerable porosity, sufficient strength for handling and transportation and mechanical resistance.

Extensive mechanized mining and rapid growing production of iron ores have resulted in the generation of a large amount of microfines, which pose a challenge to sinter makers for direct use in the sintering process due to adverse impact on sinter bed permeability. Moreover, looking at the stringent environmental norms the iron ore slurry transportation is being encouraged and practiced. During this transportation process, iron ores are crushed and ground at the mines site and transported as slurry having approximate 20% solid.

The size range of the iron ore used in the sintering process is, however, limited in its lower range (below 8 mm). The adverse impact of the use of iron ore fines on sintering performance and sinter quality has been reported in literature. In particular iron ore having more than 40% of its particles with a size below 150 microns is unacceptable for this purpose because of the risk of attaining an economically unacceptable yield in the process of sintering. The sintering raw mixes with a high proportion of fines (<150 µm) deteriorate the operation of the Dwight-Lloyd sinter machine. The low yield is due to the obstruction by the fine ore particles of the passage of the gases necessary for the combustion of the coke or coal.

Hence, for effective and gainful utilization of iron ore microfines in sintering process without impacting the sinter quality and productivity, the feed (green mix) preparation and modification in sintering process is done to accommodate the increased use of microfines in sinter making.

US Patent No. 4,273,575 titled “Process for transforming fines of iron or manganese into raw-material for sintering” reported that iron ore more than 40% of particles below 150 microns is detrimental to sintering leading to low yield due to obstruction to the passage of gases necessary for coke combustion. The proposed preparation of a micro-pellet of < 6 mm in presence of lime and molasses which was cured in a closed environment filled with carbon dioxide. Those hardened pellets can be transferred for sintering into the mix or drum. In brief process description, ore particles of size below 150 microns and humidity below 15% are mixed with agglomerates like lime, cement, bentonite, calcium chloride, silicate, and fluorosilicate of sodium in proportions that vary in accordance with the characteristics of the ore in a conventional belt mixer and then mixed mixture are conveyed to pelletizer disc, cane molasses added to mixture through the sprinkler in a varied proportion to form micro-pellets of diameter less than 6 mm, they are discharged to silos where they are hardened by subjecting them to controlled humidity and temperatures below 300 ºC, for a period of several days. These hardened spheres or micro-pellets are transported to a sintering plant where they formed into sinter and used in steel-making furnaces.

In the above patent, a new pelletizing process needs to be included which is again a capital expenditure and requires huge space. Incorporating the pelletization process along with the conventional sintering process is again a challenge. The generation of fines of the green balls obtained from pelletizing disc further depends on various factors such as its curing time, the distance of transportation from pelletizing disc to drum (if fed directly without curing), no of falls, the strength of the green balls, binder quantity, and quality, additional gangue entrance to the mix through binder addition, etc.

European Patent Application EP 0 415 146 A1 entitled “Method for manufacturing agglomerates of sintered pellets” where iron ore containing 40 wt. % or more fine materials, flux, coarse coke and return fines are mixed along with 90% of the total water addition in a drum mixer for the stipulated time period. The mixture obtained from the drum is again sent to the disc pelletizer where a balance 10% water is added for improved granulation/pelletization. The granulated mix is surface coated with the powdery coke into the drum mixer. This process also requires a pelletizing disc and thus capital expenditure and associated challenges of incorporating green balls in the conventional sintering process.

In applicants’ previous Indian Patent, Application No: 201721042832 entitled “A new process for sintering of iron ore microfines” where the micro fines were micro pelletized prior to mixing in drum along with other raw materials for blend preparation. In this invention, we claim convertion of iron ore microfines having size fractions below 150 micron to a pellet feed of size <6 mm and drop number > 7 using disc pelletizer, wherein ingredients used for disc pelletization are iron ore fines, calcined lime, limestone, dolomite, and coke breeze in varying proportions with water sprayed during pelletization for micro-pelletization. This process requires an additional capital expenditure for installing and commissioning of pelletizing disc. However, it has its own challenges and limitations such as the space requirement for disc installation along with the complete supply chain for the availability of the necessary materials including iron ore fines, fluxes, solid fuel, water addition facility etc. in the existing set up. The said process can be useful if the space permits in the existing plant set up or in the green field project where a new set up is planned to utilize more fractions of micro fines. In the present invention, the miccrofines can be utilized up to 70% in the existing plant with the conventional sintering process which makes the novelty of the process.

There has been thus an unfulfilled need to develop a process for utilization of iron ore fines with particle size ranges below 150 microns in larger proportions in commercial sintering process without any additional capital budget requirement while also ensuring desired sinter quality, product yield and productivity.

OBJECTS OF THE INVENTION

The main object of the present invention is thus to optimize the inclusion of iron ore fines in sinter mixture to achieve a better sinter yield and quality suitable for use in blast furnace iron making unit.

It is an object of the invention to provide a process for sintering of iron ore fines by effective utilization of iron ore microfines (below 150 microns) in sinter making with sustained sinter quality, product yield, and plant productivity.

Another object of the present invention is to provide an iron ore sintering composition and a method for making sinter through iron oxide fines, which obviates the drawbacks as mentioned above.

In short, the purpose of the present invention is to propose a new method that can maintain the quality as iron ore sinter for a blast furnace and increase the quality and yield more than before even when a large amount of the fine iron ore is used.

SUMMARY OF THE INVENTION

The basic aspect of the present invention is directed to an iron ore sintering composition including iron ore fines suitable for blast furnace iron making favouring product/sintered ore yield of (+5mm ) comprising 40-50% by wt. of iron ore, wherein the iron ore comprises 40-70% of iron ore having particles size <150 µm, remaining iron ore ranging from 60-30 % of total iron ore having particle size in the range of 150 µm to 8 mm; fluxes, solid fuel and 15-45% sinter return fines having particle size of <5 mm. The iron ore comprises of 28-35% of -0.15 mm and remaining 12-15% of -8 to +0.15 mm. The fluxes comprise 2.5-9.0% by wt. limestone having particle size of <3.15 mm, 2.5-8.0% by wt. dolomite having particle size of <3 mm, and 1.4-4.2% by wt. calcined lime fines (<1 mm). The solid fuel comprises 4-6% by wt. of coke breeze.

A further aspect of the present invention is directed to the iron ore sintering composition favouring iron ore sinter characteristics including product/ sintered ore yield (+5mm) in the range of 0.5 to 2.5 %, tumbler index (+6.3 mm) >65% and reduction in return fines generation in the range of 4-13%.

A still further aspect of the present invention is directed to the iron ore sintering composition having chemical composition comprising:

Fe % SiO2 % Al2O3 % CaO % MgO % MnO, % LOI %
Iron Ore 62.01 3.01 2.71 0.04 0.04 0.37 3.08
Lime Stone 0.89 2.05 0.47 50.49 2.73 0.00 42.59
Dolomite 0.79 5.22 0.67 29.05 19.49 0.00 43.97
Calcined Lime 0.31 0.81 0.28 93.94 1.49 0.00 3.05
Sinter Return Fines 53.59 6.15 6.15 3.25 11.95 2.12 0.50
Micro Pellets 41.19 6.05 2.32 25.07 3.73 0.25 10.25
Coke breeze Fe, % SiO2, % Al2O3, % CaO, % MgO, % MnO, % C, %
0.63 7.72 4.43 0.67 0.16 0.00 86.62

A still further aspect of the present invention is directed to a process for the manufacture of iron ore sinter including iron ore microfines involving the iron ore sintering composition as described above comprising:
providing the selective iron ore sintering composition comprising 40-50% by wt. of iron ore, wherein the iron ore comprises 40-70% of iron ore having particles size <150 µm, remaining iron ore ranging from 60-30 % of total iron ore having particle size in the range of 150 µm to 8 mm; fluxes comprise 2.5-9.0% by wt limestone having particle size of <3.15 mm, 2.5-8.0% by wt. dolomite having particle size of <3 mm, and 1.4-4.2% by wt. calcined lime fines (<1 mm); solid fuel comprises 4-6% by wt; and 15-45% by wt. sinter return fines having particle size of <5 mm;
adding water to said selective iron ore sintering composition;;
mixing said water and iron ore sintering composition maintaining moisture content in the range of 7.5 to 10.5 % by wt.; and
finally subjecting the mix thus obtained to granulation to obtain the granules for desired production of iron ore sinter favouring desired product/sintered ore yield of (+5mm ).

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 ACCOMPANYING DRAWINGS

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

FIG. 1 illustrates the influence of iron ore fines (< 150 µm) in iron ore sintering composition on granulation index;

FIG. 2 illustrates the influence of iron ore fines (< 150 µm) in iron ore sintering composition on tumbler index (+6.3 mm);

FIG. 3 illustrates the influence of iron ore fines (< 150 µm) in iron ore sintering composition on productivity (+5mm);

FIG. 4 illustrates the influence of iron ore fines (< 150 µm) in iron ore sintering composition on sintered iron ore yield (+5mm);

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO 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 iron ore sintering composition including iron ore fines having particles size of 150 µm or less. In the present invention the finer fractions up to 70% below 150 µm size fractions of iron ore are incorporated in the conventional process itself without deterioration of quality and yield. The present invention is directed to a iron ore sintering composition involving mixing homogeneously the balance sinter mix ingredients which includes sinter return fines (<5 mm), iron ore sinter grade size fraction (<8 mm), iron ore fines (<150 µm), limestone (<3.15 mm), dolomite (<3 mm), solid fuel (< 3.15mm) and calcined lime fines (<1 mm). The iron ore sinter composition improves the granulation index and ensure minimum fines generation which otherwise hampers the bed permeability, sinter productivity and quality. The iron ore sinter composition ensures an optimum granulation and optimum carbon requirement and thereby better heat transfer and slag formation leading to improvement in sinter strengths. The iron ore sinter composition ensures an optimum flux and fuel addition which should facilitate effective heat utilization and melt formation with required melt viscosity.

The basic aspect of the present invention is directed to an iron ore sintering composition comprising 40-50% of total iron ore, fluxes, solid fuel and 15-45% sinter return fines having particle size of <5 mm. The iron ore comprises 28-35% of iron ore having particles size of 150 µm, 12-15% of iron ore having particle size of <8 mm. The fluxes comprise 2.5-9.0% limestone having particle size of <3.15 mm, 2.5-8.0% dolomite having particle size of <3 mm, and 1.4-4.2% calcined lime fines (<1 mm). The solid fuel comprises 4-6% of coke breeze. The iron ore having particles size of 150 µm are also called PG fines or pellet grade fines. The terms are used interchangeably in the present invention.

The iron ore sintering composition favouring iron ore sinter characteristics includes enhanced product/ sintered ore yield (+5mm) in the range of 0.5 to 2.5 % w.r.t the conventional process), tumbler index (+6.3 mm) is >65% and reduction in return fines generation is in the range of 4-13%.

A still further aspect of the present invention is directed to the composition comprising:

Fe % SiO2 % Al2O3 % CaO % MgO % MnO, % LOI %
Iron Ore 62.01 3.01 2.71 0.04 0.04 0.37 3.08
Lime Stone 0.89 2.05 0.47 50.49 2.73 0.00 42.59
Dolomite 0.79 5.22 0.67 29.05 19.49 0.00 43.97
Calcined Lime 0.31 0.81 0.28 93.94 1.49 0.00 3.05
Sinter Return Fines 53.59 6.15 6.15 3.25 11.95 2.12 0.50
Micro Pellets 41.19 6.05 2.32 25.07 3.73 0.25 10.25
Coke breeze Fe, % SiO2, % Al2O3, % CaO, % MgO, % MnO C, %
0.63 7.72 4.43 0.67 0.16 0.00 86.62

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 contents, 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.

In addition, unless otherwise specified, % means weight%.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to 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.

The present invention is described further hereinafter by reference to a series of examples.

Experiments that were actually performed are now described by way of following examples.

Examples

Example I: Analysis of Sinter Plant Data
The statistical analysis of the sinter plant data was performed to understand an impact of microfines on sintering parameters and sinter qualities, as stated below.
The sintered iron ore productivity and corresponding physical properties are correlated with
-100# content and mean size of iron ore fines and following relation was established:

It is understood from the data analysis that the productivity, TI and Cum +10mm reduces with increase in -100mesh (#) [below 150 µm] size fraction of iron ore in sinter mix.

Effect of Calcined lime/Burnt Lime on sintered ore properties

Calcines lime improves binding of the sinter green mix which further improves the granulation index and thus the sintered iron ore productivity. The data analysis were used to identify the relationship between calcined lime and below 150 µm size fractions of iron ore with waste gas fan (WGF) speed and the obtained relation is as under:

[Calcined lime] = 0.464 * [-100# in IOF] + 0.107 * [WGF speed] - 170.67

While keeping the WGF speed and found the relationship between calcined lime and -100# IOF, the relationship turns to:

[Calcined lime] = 0.4175 * [IOF Conc % in total blend] +23.107

With increase in 1% of iron ore fines in total blend, the calcines lime requirement increases by ~0.42 kg/t of Sinter to sustain the same permeability and thereby productivity.

Based on the above relationship, calcined lime is varied with respect to the change in -100# size fractions IOF.

Example II: Iron ore sintering composition

Experiment No. 1 2 3 4 5
(%) of Iron ore fines (< 150 µm) of Total Iron Ore Fines 0 40 50 60 70
Iron ore fines (< 150 µm) / Pellet Grade fines (PG fines) 0.00 24.00 30.00 36.00 42.00
Iron Ore (I/O) (<8 mm) 59.96 36.00 30.00 24.00 18.00
Sinter Return Fines 17.00 17.00 17.00 17.00 17.00
Limestone 5.94 4.50 4.50 4.50 4.50
Dolomite 6.20 6.20 6.20 6.20 6.20
Coke Fines 4.20 4.20 4.20 4.20 4.20
Burnt Lime / Calcined Lime 1.70 3.10 3.10 3.10 3.10
Micro Pellet 5.00 5.00 5.00 5.00 5.00
Total 100 100 100 100 100
Moisture Addition, % 8.00 9.00 10.30 10.49 10.58
*Size fractions (< 150 µm) in total mix,% 36.19 51.50 55.33 59.16 62.99
#Size fractions (< 150 µm) in Total Iron ore, % 33.00 59.80 66.50 73.20 79.90
* Total size fractions (< 150 µm) in iron ore sintering composition having 0% iron ore fines (< 150 µm) is considered @ 36.19%
# Total size fractions (< 150 µm) in total iron ore is considered @ 33.00%

Example III: Preparation of the Granules by Granulation and Granules Evaluation

Firstly, the iron ore sintering composition were prepared. Secondly, water was added into the iron ore sintering composition. Thirdly, the water and iron ore sintering composition were mixed to obtain a mixture. The moisture content in the mixture was in the range of 7.5-10.5% by mass. Fourthly, the mixture was granulated to obtain granules.

Granulation Index
(%) of iron ore fines (< 150 µm) 0 40 50 60 70
Wt. % of < 0.5 mm particle in dry mix 29.00 33.00 36.00 38.00 41.00
Wt. % of < 0.5 mm particle in wet mix 3.50 4.50 6.00 7.50 8.50
Granulation Index, 0.5 mm (GI) 87.93 86.36 83.33 80.26 79.27

The quality of the sinter mainly depends on the sinter granulometry. Sinter granulometry and depends on the particle size of the iron ore fines required for making sinter granules. The produced sinter for blast furnace iron making unit should have optimum physical and metallurgical properties. For making good quality of sinter optimum with percentage of the iron ore fines in the raw material with particles size of 150 µm or less in sinter mixture is essential.

Accompanying FIG. 1 illustrates the influence of iron ore fines (< 150 µm) in iron ore sintering composition on granulation index.

Example IV: Preparation of the iron ore sinter and evaluation of various properties of iron ore sinter
The granules were ignited. The ignition suction was in the range of 600-700 mmH2O and ignition temperature of 1150-1160oC. The granules were sintered. The sintering suction was in the range of 1200-1300 mmH2O. The mass percentage of coke breeze was in the range of 58-60 kg/t and carbon rate of the coke breeze is in the range of 48-49.5 kg/t.The basicity of the iron ore sinterwas in the range of 1.8-2.20%. The mass percentage of MgO in the iron ore sinter which is in the range of 2.0-2.40%.

The increase in iron ore fines (< 150 µm) in the iron ore sintering composition, increased the finer size fractions (< 0.5 mm) after dry mixing. The reduced granulation index (G.I 0.5mm) (around 10% with 70% iron ore fines (< 150 µm) fines usage). The increased sintering time this consequently reduces the productivity of sinter. The cold strength property (TI) of sinter increased significantly. There was a significant increase in product yield (+5 mm) and consequently reduced return fines. The productivity loss of the sinter increased by 2.59, 5.80, 9.30 and 9.23% respectively with increase in iron ore fines (< 150 µm) in blend from 40, 50, 60 and 70% of iron ore fines. The replacement of iron ore with iron ore fines (< 150 µm) by 40 to 50% of iron ore, increases the finer size fractions (< 150 µm) to ~60 and 66 % in iron ore respectively. The addition of iron ore fines (< 150 µm) to 40% of total iron ore in sinter mix has shown improvement in tumbler index by increasing solid fuel consumption from 4 to 4.2%.
Accompanying FIG. 2 illustrates the influence of iron ore fines (< 150 µm) in iron ore sintering composition on tumbler index (+6.3 mm).
Accompanying FIG. 3 illustrates the influence of iron ore fines (< 150 µm) in iron ore sintering composition on productivity (+5mm) and sintering time;

Accompanying FIG. 4 illustrates the influence of iron ore fines (< 150 µm) in iron ore sintering composition on sintered iron ore yield (+5mm);

There limestone consumptions reduced to 17kg/ton of sinter. The cold strength property and product yield (+5mm) enhanced. As a consequence, the plant return fines reduced and thus expected to reduce fines generation at blast furnace also, due to increase in TI. Accompanying FIG. 4 illustrates the influence of iron ore fines (< 150 µm) in iron ore sintering composition on reduction in plant Return Fines (-5 mm)[ Fig. 4].
The scope of procuring low cost I/O fines with high gangue and beneficiate it to upgrade. Theoretically, there is a 1% increase in Fe in total Iron ore blend, the hot Metal Production is expected to increase by 11tpd and the slag rate is expected to decrease by 0.325 kg/tHM.