Claims:WE CLAIM:
1. A composition comprising iron ore fines, coal, limestone, bentonite and peridotite.
2. The composition as claimed in claim 1, wherein the iron ore fines are in an amount ranging from about 92 wt% to 95 wt%; and wherein about 55 wt% to 62 wt% of the iron ore fines has particle size of about -45 microns.
3. The composition as claimed in claim 1, wherein the coal is in an amount ranging from about 1 wt% to 1.5 wt%; and wherein about 55 wt% to 60 wt% of the coal has particle size of about -45 microns.
4. The composition as claimed in claim 1, wherein the limestone is in an amount ranging from about 2 wt% to 3.5 wt%; and wherein about 55 wt% to 65 wt% of the limestone has particle size of about -45 microns.
5. The composition as claimed in claim 1, wherein the bentonite is in an amount ranging from about 0.35 wt% to 0.6 wt%; and wherein about 65 wt% to 85 wt% of the bentonite has particle size of about -45 microns.
6. The composition as claimed in claim 1, wherein the peridotite is in an amount ranging from about 3.5 wt% to 4.8 wt% and wherein about 55 wt% to 65 wt% of the peridotite has particle size of about -45 microns.
7. The composition as claimed in claim 1, wherein the iron ore fines comprises about 60 wt% to 64 wt% of Fe(t), about 3 wt% to 4.8 wt% of SiO2, about 2 wt% to 4 wt% of Al2O3, about 0.02 wt% to 0.5 wt% of CaO and about 0.01 wt% to 0.3 wt% of MgO; and the iron ore fines has loss on ignition (LOI) ranging from about 1 to 5.
8. The composition as claimed in claim 1, wherein the coal comprises about 0.35 wt% to 0.85 wt% of Fe(t), about 3.5 wt% to 5 wt% of SiO2, about 1.8 wt% to 2.5 wt% of Al2O3, about 0.1 wt% to 0.8 wt% of CaO and about 0.05 wt% to 0.5 wt% of MgO and wherein the coal has fixed carbon ranging from about 75 wt% to 93 wt%.
9. The composition as claimed in claim 1, wherein the limestone 0.5 wt% to 2.5 wt% of SiO2, about 0.2 wt% to 0.5 wt% of Al2O3, about 45 wt% to 55 wt% of CaO and about 0.25 wt% to 0.6 wt% of MgO; and the limestone has loss on ignition (LOI) ranging from about 40 to 55.
10. The composition as claimed in claim 1, wherein the bentonite comprises about 7 wt% to 12 wt% of Fe(t), about 38 wt% to 47 wt% of SiO2, about 12 wt% to 17 wt% of Al2O3, about 1 wt% to 2.2 wt% of CaO and about 1.5 wt% to 3 wt% of MgO; and the bentonite has loss on ignition (LOI) ranging from about 5 to 20
11. The composition as claimed in claim 1, wherein the peridotite comprises about 4 wt% to 8 wt% of Fe(t), about 25 wt % to 35 wt% of SiO2, about 0.25 wt% to 6 wt% of Al2O3, about 0.5 wt% to 1.5 wt% of CaO and about 36 wt% to 44 wt% of MgO; and the peridotite has loss on ignition (LOI) ranging from about 7 to 15.
12. A method for preparing iron ore pellet, said method comprising-
- mixing the iron ore fine, the limestone, the bentonite, the coal and the peridotite to obtain the composition as claimed in claim 1; and
- adding solvent to the composition and preparing pellet, followed by heating to obtain the iron ore pellet.
13. The method as claimed in claim 12, wherein prior to the mixing, the iron ore fines, the limestone, the bentonite, the coal are subjected to grinding to obtain about 55 wt% to 62 wt% of the iron ore fines having particle size of about -45 microns, about 55 wt% to 65 wt% of the limestone having particle size of about -45 microns, about 65 wt% to 85 wt% of the bentonite having particle size of about -45 microns, about 55 wt% to 60 wt% of the coal having particle size of about -45 microns, about 55 wt% to 65 wt% of the peridotite having particle size of about -45 microns.
14. The method as claimed in claim 12, wherein the solvent is water and wherein the solvent is in an amount ranging from about 6 wt.% to 9 wt.%.
15. The method as claimed in claim 12, wherein preparing the pellet involves subjecting the composition to a pelletizer to obtain the pellets.
16. The method as claimed in claim 12, wherein the pellets are subjected to the heating at a temperature ranging from about 1250 °C to 1320 °C, for a duration ranging from about 2 minutes to 5 minutes.
17. An iron ore pellet prepared according to the method as claimed in claim 12.
18. The iron ore pellet as claimed in claim 17, wherein the iron ore pellet has cold compressive strength ranging from about 200 kg/pellet to 240 kg/pellet; the iron ore pellet has swelling index ranging from about 13% to 17%; the iron ore pellet has reducibility index ranging from about 65 to 75; the iron ore pellet has porosity ranging from about 23% to 28%; the iron ore pellet has HOSIM time ranging from about 140 minutes to 150 minutes; the iron ore pellet has size ranging from about 10 mm to 12.5 mm.
19. Use of the iron ore pellet as claimed in claim 17 for producing industrial metal and/or alloy.
, Description:TECHNICAL FIELD
The present disclosure relates to the field of metallurgy. The disclosure particularly relates to a composition comprising iron ore fines, coal, limestone, bentonite and peridotite. The disclosure further relates to a method of preparing iron ore pellet employing the composition, iron ore pellet having improved pellet properties and use of the iron ore pellet for manufacturing industrial metals.

BACKGROUND OF THE DISCLOSURE
Pelletization is an agglomeration process of iron ore fines of less than 150 microns along with some fluxes and binders into green pellets having pellet size of 10 to 12.5 mm followed by induration to get the desired characteristics of pellets.

Pellet quality plays a vital role in decreasing the reducing agent or fuel, such as coke consumption and increasing the productivity of blast furnace. Large capacity high rate blast furnaces demand very high quality pellets to achieve high productivity and low fuel rate (i.e., coke rate). The properties of iron ore pellets depend on the type of slag bonds formed, mainly depends on the type and composition of fluxes added and indurating conditions. However, it is noted that due to high amount of unwanted gangue materials like silica and alumina, it is challenging to obtain good quality pellets that meets the requirement of blast furnace.

Thus, there is a need to develop good quality pellets that meet the requirement of blast furnace, in a simple and economical manner.

STATEMENT OF THE DISCLOSURE
Accordingly, the present disclosure provides a composition for preparing high quality iron ore pellet having improved pellet properties, such as cold compressive strength, swelling index, reducibility index, HOSIM time and porosity. The said composition is simple, economical and environmentally friendly.

In an embodiment of the present disclosure, the composition comprises iron ore fines, coal fines, limestone, bentonite and peridotite.

The present disclosure further describes a method for preparing iron ore pellet, said method comprising- mixing the iron ore fine, the limestone, the bentonite, the coal and peridotite to obtain said composition; and adding solvent to the composition and preparing pellet, followed by heating to obtain desired properties.

The present disclosure further relates to iron ore pellet having improved pellet properties, such as cold compressive strength, swelling index, reducibility index, HOSIM time and porosity.

The present disclosure further relates to use of iron ore pellet for producing industrial metals.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURE
In order that the present disclosure may be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figure. The figure together with detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, where:

FIGURE 1 illustrates optical image of iron ore pellets of the present disclosure. The image clearly shows silicate bonds and Magnesio ferrite bonds.

DETAILED DESCRIPTION OF THE DISCLOSURE
Definitions:
Unless otherwise defined, all terms used in the disclosure, including technical and scientific terms, have meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included for better understanding of the present disclosure.

As used herein, the singular forms ‘a’, ‘an’ and ‘the’ include both singular and plural referents unless the context clearly dictates otherwise.

The term ‘comprising’, ‘comprises’ or ‘comprised of’ as used herein are synonymous with ‘including’, ‘includes’, ‘containing’ or ‘contains’ and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps.

The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within the respective ranges, as well as the recited endpoints.

The term ‘about’ as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of ±10% or less, preferably ±5% or less, more preferably ±1% or less and still more preferably ±0.1% or less of and from the specified value, insofar such variations are appropriate to perform the present disclosure. It is to be understood that the value to which the modifier ‘about’ refers is itself also specifically, and preferably disclosed.

The term ‘cold compressive strength (CCS)’ of the pellets indicate the ability of the pellets to withstand the load during their storage, handling and the load of the burden material in the reduction furnace. The pellets for use in the blast furnace should have CCS in the range of 200 kg/pellets to 300 kg/pellets.

The term ‘swelling index (SI)’ indicates the volume change of pellets during reduction. Higher SI of pellets reduces the strength of the pellets after their reduction and thereby causing irregularities in the blast furnace. The pellets for use in the blast furnace should have SI in the range of 14% to 16%.

The term ‘reducibility index (RI)’ indicates reducibility of the pellets., i.e., the ease with which the oxygen combined with the iron oxide can be removed. A higher reducibility indicates more indirect reduction in the blast furnace resulting in lower coke rate and high productivity.

The term ‘particle size of about -45 microns’ means that the particles of the iron ore fines, coal, limestone, bentonite and peridotite, respectively passes through sieve having size of about 45 microns, meaning that the particle of the iron ore fines, coal limestone, bentonite and peridotite, respectively have particle size of less than 45 microns. Less than 45 microns means, particle size of the iron ore fines, limestone, bentonite and peridotite are under 45 microns, respectively as the components passes through the 45 micron sieve.

Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment may be included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification may not necessarily all refer to the same embodiment. It is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

The present disclosure relates to a composition comprising iron ore fines, coal, limestone, bentonite and peridotite.

In an embodiment of the present disclosure, the said composition is a pellet composition.

In an embodiment of the present disclosure, the iron ore fines comprises about 60 wt% to 64 wt% of Fe(t), about 3 wt% to 4.8 wt% of SiO2, about 2 wt% to 4 wt% of Al2O3, about 0.02 wt% to 0.5 wt% of CaO and about 0.01 wt% to 0.3 wt% of MgO.

In another embodiment of the present disclosure, the iron ore fines comprises about 61.25 wt.% of Fe(t), about 4.33 wt.% of SiO2, about 3.91 wt.% of Al2O3, about 0.04 wt.% of CaO and about 0.01 wt.% of MgO.

In an embodiment of the present disclosure, the iron ore fines have loss on ignition (LOI) ranging from about 1 wt% to 5 wt%

In another embodiment of the present disclosure, the iron ore fines have loss on ignition (LOI) of about 1 wt%, about 2 wt %, about 3 wt%, about 4 wt% or about 5 wt%.

In another embodiment of the present disclosure, the iron ore fines have loss on ignition (LOI) of about 3.24 wt%.

In an embodiment of the present disclosure, the bentonite comprises about 7 wt% to 12 wt% of Fe(t), about 38 wt% to 47 wt% of SiO2, about 12 wt% to 17 wt% of Al2O3, about 1 wt% to 2.2 wt% of CaO and about 1.5 wt% to 3 wt% of MgO.

In another embodiment of the present disclosure, the bentonite comprises about 9.72 wt.% of Fe(t), about 45.97 wt.% of SiO2, about 14.49 wt.% of Al2O3, about 1.78 wt.% of CaO and about 2.24 wt.% of MgO.

In an embodiment of the present disclosure, the bentonite has loss on ignition (LOI) ranging from about 5 wt% to 20 wt%

In another embodiment of the present disclosure, the bentonite has loss on ignition (LOI) of about 5wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt% about 18 wt%, about 19 wt% or about 20 wt%.

In another embodiment of the present disclosure, the bentonite has loss on ignition (LOI) of about 17.6 wt%.

In an embodiment of the present disclosure, the limestone comprises about 0.5 to 2.5 of SiO2, about 0.2 wt% to 0.5 wt% of Al2O3, about 45 wt% to 55 wt% of CaO and about 0.25 wt% to 0.6 wt% of MgO.

In another embodiment of the present disclosure, the limestone comprises about 1.55 wt.% of SiO2, about 0.31wt.% of Al2O3, about 53.01 wt.% of CaO and about 0.43 wt.% of MgO.

In an embodiment of the present disclosure, the limestone has loss on ignition (LOI) ranging from about 40 wt% to 55 wt%.

In another embodiment of the present disclosure, the limestone has loss on ignition (LOI) ranging from about 40 wt%, about 41 wt%, about 42 wt%, about 43 wt%, about 44 wt%, about 45 wt%, about 46 wt%, about 47 wt%, about 48 wt%, about 49 wt%, about 50 wt%, about 51 wt%, about 52 wt%, about 53 wt%, about 54 wt% or about 55 wt%.

In another embodiment of the present disclosure, the limestone has loss on ignition (LOI) of about 43.56 wt%.

In an embodiment of the present disclosure, the peridotite comprises about 4 wt% to 8 wt% of Fe(t), about 25 wt% to 35 wt% of SiO2, about 0.25 wt% to 6 wt% of Al2O3, about 0.5 wt% to 1.5 wt% of CaO and about 36 wt% to 44 wt% of MgO.

In another embodiment of the present disclosure, the peridotite comprises about 6.51wt.% of Fe(t), about 32.23 wt.% of SiO2, about 0.34 wt.% of Al2O3, about 0.98 wt.% of CaO and about 41.66 wt.% of MgO.

In an embodiment of the present disclosure, the peridotite has loss on ignition (LOI) ranging from about 7 wt% to 15 wt%.

In another embodiment of the present disclosure, the peridotite has loss on ignition (LOI) of about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt% or about 15 wt%.

In another embodiment of the present disclosure, the peridotite has loss on ignition (LOI) of about 14.23 wt%.

In an embodiment of the present disclosure, the coal comprises about 0.35 wt% to 0.85 wt% of Fe(t), about 3.5 wt% of to 5 wt% of SiO2, about 1.8 wt% to 2.5 wt% of Al2O3, about 0.1 wt% to 0.8 wt% of CaO and about 0.05 wt% to 0.5 wt% of MgO.

In another embodiment of the present disclosure, the coal comprises about 0.65 wt.% of Fe(t), about 5.2 wt.% of SiO2, about 2.21 wt.% of Al2O3, about 0.15 wt.% of CaO and about 0.14 wt.% of MgO.

In an embodiment of the present disclosure, the coal is selected from a group comprising anthracite coal, coke breeze, Coke dry quenching (CDQ) dust, flue dust and GCP sludge.

In an embodiment of the present disclosure, the iron ore fines are in an amount ranging from about 92 wt% to 95 wt%.

In another embodiment of the present disclosure, the iron ore fines are in an amount of about 92 wt%, about 92.5 wt%, about 93 wt%, about 93.5 wt%, about 94 wt%, about 94.5 wt% or about 95 wt%.

In an embodiment of the present disclosure, about 55 wt% to 62 wt% of the iron fines have particle size of about -45 microns.

In an embodiment of the present disclosure, the bentonite is in an amount ranging from about 0.35 wt% to 0.6 wt%.

In another embodiment of the present disclosure, the bentonite is in an amount of about 0.35 wt% about 0.36 wt%, about 0.37 wt%, about 0.38 wt%, about 0.39 wt%, about 0.40 wt%, about 0.41 wt%, about 0.42 wt%, about 0.43 wt%, about 0.44 wt%, about 0.45 wt%, about 0.46 wt%, about 0.47 wt%, about 0.48 wt%, about 0.49 wt%, about 0.50 wt%, about 0.51 wt%, about 0.52 wt%, about 0.53 wt%, about 0.54 wt%, about 0.55 wt%, about 0.56wt%, about 0.57wt%, about 0.58 wt%, about 0.59 wt% or about 0.6 wt%.

In an embodiment of the present disclosure, about 65 wt% to 85 wt% of the bentonite has particle size of about-45 microns.

In an embodiment of the present disclosure, the limestone is in an amount ranging from about 2 wt% to 3.5 wt%.

In another embodiment of the present disclosure, the limestone is in an amount of about 2.0 wt%, about 2.1wt%, about 2.2 wt%, about 2.3 wt%, about 2.4 wt%, about 2.5 wt%, about 2.6 wt%, about 2.7 wt%, about 2.8 wt%, about 2.9 wt%, about 3.0 wt%, about 3.1 wt%, about 3.2 wt%, about 3.3 wt%, about 3.4 wt% or about 3.5 wt%.

In an embodiment of the present disclosure, about 55 wt% to 65 wt% of the limestone has particle size of about -45 microns.

In an embodiment of the present disclosure, the peridotite is in an amount ranging from about 3.5wt% to 4.8 wt%.

In another embodiment of the present disclosure, the peridotite is in an amount of about 3.5 wt%, about 3.6 wt%, about 3.7 wt%, about 3.8 wt%, about 3.9 wt%, about 4.0 wt%, about 4.1 wt%, about 4.2 wt%, about 4.3 wt%, about 4.4 wt%, about 4.5 wt%, about 4.6 wt%, about 4.7 wt% or about 4.8 wt%.

In an embodiment of the present disclosure, about 55 wt% to 65 wt% of the peridotite has particle size of about -45 microns.

In an embodiment of the present disclosure, the coal is in an amount ranging from about 1 wt% to 1.5 wt%

In another embodiment of the present disclosure, the coal is in an amount of about 1 wt%, about 1.1 wt%, about 1.2 wt%, about 1.3 wt%, about 1.4 wt% or about 1.5 wt%.

In an embodiment of the present disclosure, about 55 wt% to 60 wt% of the coal has particle size of about -45 microns.

The present disclosure further relates to method of preparing iron ore pellet.

In an embodiment of the present disclosure, the method of preparing iron ore pellet comprises-
- mixing the iron ore fine, the limestone, the bentonite, the coal and the peridotite to obtain the composition as described above; and
- adding solvent to the composition and preparing pellet, followed by heating the pellet to obtain the iron ore pellet.

In an embodiment of the present disclosure, prior to the mixing, the iron ore fines, the limestone, the bentonite, the coal and the peridotite is subjected to grinding respectively in order to obtain specific particle size of each of the said components, wherein about 55 wt% to 62 wt% of the iron ore fines have particle size of about -45 microns, about 55 wt% to 65 wt% of the limestone has particle size of about -45 microns, about 65 wt% to 85 wt% of the bentonite has particle size of about -45 microns, about 55 wt% to 60 wt% of the coal has particle size of about -45 microns, about 55 wt% to 65 wt% of the peridotite has particle size of about -45 microns.

In another embodiment of the present disclosure, the method of preparing iron ore pellet comprises-
- grinding the iron ore fines, the limestone, the bentonite, the coal and the peridotite, respectively;
- mixing the ground iron ore fines, the ground limestone, the ground bentonite, the ground coal and the ground peridotite to obtain homogenous mixture;
- adding solvent to the homogenous mixture, followed by mixing and preparing pellets; and
- heating the pellets to obtain the iron ore pellets.

In another embodiment of the present disclosure, the iron ore fines, the limestone, the bentonite, the coal and the peridotite, respectively is subjected to grinding to obtain about 55 wt% to 62 wt% of the iron ore fines having particle size of about -45 microns, about 55 wt% to 65 wt% of the limestone having particle size of about -45 microns, about 65 wt% to 85 wt% of the bentonite having particle size of about -45 microns, about 55 wt% to 60 wt% of the coal having particle size of about -45 microns, about 55 wt% to 65 wt% of the peridotite having particle size of about -45 microns.

In an embodiment of the present disclosure, the iron ore fines, the limestone, the bentonite, the coal and the peridotite are mixed in a mixer including but not limited to turbo mixer to obtain homogenous mixture. The mixing is carried out for a duration ranging from about 1 minute to 5 minutes.

In another embodiment of the present disclosure, the iron ore fines, the limestone, the bentonite, the coal and the peridotite are mixed in a mixer for a duration of about 1 minute, about 1.5 minutes, about 2 minutes, about 2.5 minutes about 3 minutes, about 3.5 minutes, about 4 minutes, about 4.5 minutes or about 5 minutes.

In an embodiment of the present disclosure, the solvent is water.

In an embodiment of the present disclosure, the solvent is added in an amount ranging from about 6 wt.% to 9 wt.%.

In another embodiment of the present disclosure, the solvent is added in an amount of about 6 wt.%, about 7 wt.%, about 8 wt.% or about 9 wt.%.

In an embodiment of the present disclosure, the pellet is prepared by subjecting the homogenous mixture of the composition to a pelletizer including but not limited to disc based pelletizer and drum based pelletizer.

In another embodiment of the present disclosure, the pellet is prepared by subjecting the homogenous mixture of the composition to a ball disc pelletizer having a diameter of about 600 mm, an edge height of about 200 mm and a tilting angel of about 45º, at a speed of about 27 rpm.

In an embodiment of the present disclosure, the pellets are heated at a temperature ranging from about 1250 °C to 1320 °C for a duration ranging from about 2 minutes to 5 minutes. The heating is carried out in a furnace including but not limited to induration furnace.

In another embodiment of the present disclosure, the pellets are heated in induration furnace at a temperature of about 1250 °C, about 1260 °C, about 1270 °C, about 1280 °C, about 1290 °C, about 1300 °C, about 1310 °C or about 1320 °C for a duration of about 2 minutes, about 3 minutes, about 4 minutes or about 5 minutes.

In another embodiment of the present disclosure, the heating is rapid heating at a temperature ranging from about 1250 °C to 1320 °C, for a duration ranging from about 5minutesto 10 minutes in a furnace including but not limited to nabertherm furnace and muffle furnace.

In another embodiment of the present disclosure, the pellets are subjected to rapid heating in nabertherm furnace and/or muffle furnace at a temperature of about 1250 °C, about 1260 °C, about 1270 °C, about 1280 °C, about 1290 °C, about 1300 °C, about 1310 °C or about 1320 °C for a duration of about 5 minutes, about 6 minutes, about 7 minutes, about 8 minutes, 9 minutes or about 10 minutes.

In an embodiment of the present disclosure, the pellets have particle size ranging from about 10 mm to 12. 5 mm.

In another embodiment of the present disclosure, the pellets have particle size of about 10 mm, about 10.5 mm, about 11 mm, about 11.5 mm, about 12 mm or about 12.5 mm.

The porosity of the iron ore pellet is ranging from about 3 % to 5 % higher when compared to known iron ore pellet (prepared using Mgo source other than peridotite). The higher porosity of the iron ore pellet of the present disclosure provides improved permeability in the furnace bed.

In another embodiment of the present disclosure, the porosity of the iron ore pellet is about 3 %, about 4 % or about 5 % higher when compared to iron ore pellet prepared using MgO source other than peridotite.

In an embodiment of the present disclosure, the peridotite in the composition while preparing pellet results in formation of uniform magnesio ferrite and silicate bonds. The described bond in the pellet provides for improved pellet properties.

In an embodiment of the present disclosure, the method of preparing the iron ore pellet is simple and economical. The said method enables decrease in flux cost in pellet making.

The present disclosure further relates to iron ore pellets prepared according to the above described method.

In an embodiment of the present disclosure, said iron ore pellets have improved pellet properties, such as cold compressive strength, swelling index, reducibility index, HOSIM time and porosity.

In an embodiment of the present disclosure, the iron ore pellet has cold compressive strength ranging from about 200 kg/pellet to 240 kg/pellet.

In another embodiment of the present disclosure, the iron ore pellet has cold compressive strength of about 205 kg/pellet, about 210 kg/pellet, about 215 kg/pellet, about 220 kg/pellet, about 225 kg/pellet, about 230 kg/pellet, about 235 kg/pellet or about 240 kg/pellet.

In another embodiment of the present disclosure, the iron ore pellet has cold compressive strength of about 214 kg/pellet.

In another embodiment of the present disclosure, the improved cold compressive strength ranging from about 200 kg/pellet to 240kg/pellet demonstrated by the iron ore pellet indicates the ability of the pellets to withstand the load during their storage, handling and the load of burden material in reduction furnace.

In an embodiment of the present disclosure, the iron ore pellet has swelling index ranging from about 13 % to 17%.

In another embodiment of the present disclosure, the iron ore pellet has swelling index of about 13%, about 14%, about 15%, about 16% or about 17%.

In another embodiment of the present disclosure, the iron ore pellet has swelling index of about 15.32%

In another embodiment of the present disclosure, the swelling index ranging from about 13% to 17% of the iron ore pellets provides for increased productivity when used in blast furnace.

In an embodiment of the present disclosure, the iron ore pellet has reducibility index ranging from about 65 to 75.

In another embodiment of the present disclosure, the iron ore pellet has reducibility index of about 65, about 66, about 67, about 68, about 69, about 70, about 71, about 72, about 73, about 74 or about 75.

In another embodiment of the present disclosure, the iron ore pellet has reducibility index of about 73.41.

In another embodiment of the present disclosure, the reducibility index ranging from about 65 to 75 of the iron ore pellets leads to lower carbon rates when used in blast furnace.

In an embodiment of the present disclosure, the iron ore pellet has porosity ranging from about 23 % to 28%.

In another embodiment of the present disclosure, the iron ore pellet has porosity ranging from about 23%, about 24%, about 25%, about 26%, about 27% or about 28%.

In another embodiment of the present disclosure, the iron ore pellet has porosity of about 27.2%.

In another embodiment of the present disclosure, the porosity ranging from about 23% to 28% of the iron ore pellet provides higher reducibility.

In an embodiment of the present disclosure, the iron ore pellet has HOSIM time ranging from about 140 minutes to 150 minutes.

In another embodiment of the present disclosure, the iron ore pellet has HOSIM time of about 141 minutes, about 142 minutes, about 143 minutes, about 144 minutes, about 145 minutes, about 146 minutes, about 147 minutes, about 148 minutes, about 149 minutes or about 150 minutes.

In an embodiment of the present disclosure, the iron ore pellet comprises about 92 wt% to 95 wt% of iron ore fines, about 0.3 wt% to 0.6 wt% of bentonite, about 1wt% to 1.5 wt% of coal, about 2 wt% to 3.5 wt% of limestone and about 3.5 wt% to 4.8 wt% of peridotite.

In an embodiment of the present disclosure, the iron ore fines in the iron ore pellet is about 92 wt%, about 92.5 wt%, about 93 wt%, about 93.5 wt%, about 94 wt%, about 94.5 wt% or about 95 wt%.

In an embodiment of the present disclosure, the bentonite in the iron ore pellet is about 0.35 wt% about 0.36 wt%, about 0.37 wt%, about 0.38 wt%, about 0.39 wt%, about 0.40 wt%, about 0.41 wt%, about 0.42 wt%, about 0.43 wt%, about 0.44 wt%, about 0.45 wt%, about 0.46 wt%, about 0.47 wt%, about 0.48 wt%, about 0.49 wt%, about 0.50 wt%, about 0.51 wt%, about 0.52 wt%, about 0.53 wt%, about 0.54 wt%, about 0.55 wt%, about 0.56wt%, about 0.57wt%, about 0.58 wt%, about 0.59 wt% or about 0.6 wt%.

In an embodiment of the present disclosure, the limestone in the iron ore pellet is in an amount of about 2.0 wt%, about 2.1wt%, about 2.2 wt%, about 2.3 wt%, about 2.4 wt%, about 2.5 wt%, about 2.6 wt%, about 2.7 wt%, about 2.8 wt%, about 2.9 wt%, about 3.0 wt%, about 3.1 wt%, about 3.2 wt%, about 3.3 wt%, about 3.4 wt% or about 3.5 wt%.

In an embodiment of the present disclosure, the peridotite in the iron ore pellet is in amount of about 3.5 wt%, about 3.6 wt%, about 3.7 wt%, about 3.8 wt%, about 3.9 wt%, about 4.0 wt%, about 4.1 wt%, about 4.2 wt%, about 4.3 wt%, about 4.4 wt%, about 4.5 wt%, about 4.6 wt%, about 4.7 wt% or about 4.8 wt%.

In another embodiment of the present disclosure, the iron ore pellet comprises about 92.4 wt% of iron ore fine, about 0.46 wt% of bentonite, about 1.02 wt% of coal, about 2.1 wt% of limestone and about 4.02 wt% of peridotite.

The present disclosure further relates to use of the iron ore pellets.

In an embodiment of the present disclosure, the iron ore pellets are used for manufacturing industrial metal.

In an embodiment of the present disclosure, the iron ore pellets are used for manufacturing alloy.

It is to be understood that the foregoing description is illustrative not a limitation. While considerable emphasis has been placed herein on particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. Those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein. Similarly, additional embodiments and features of the present disclosure will be apparent to one of ordinary skill in art based upon description provided herein.

Descriptions of well-known/conventional methods/steps and techniques are omitted so as to not unnecessarily obscure the embodiments herein. Further, the disclosure herein provides for examples illustrating the above-described embodiments, and in order to illustrate the embodiments of the present disclosure, certain aspects have been employed. The examples used herein for such illustration are intended merely to facilitate an understanding of ways in which the embodiments may be practiced and to further enable those of skill in the art to practice the embodiments. Accordingly, following examples should not be construed as limiting the scope of the embodiments herein.

EXAMPLE

Example 1: Preparation of iron ore pellet.
Iron ore fines having particle size ranging from about 1 mm to 15 mm, limestone fines having particle size ranging from about 10 mm to 20mm, bentonite having particle size ranging from about 1 mm to 10mm, anthracite coal having particle size of about 30mm and peridotite having particle size of about 30mm were ground separately in a ball mill to achieve desired size. The overall size was maintained at about -45micron for 55wt.% to 85 wt% of the said components. The ground iron ore fines, bentonite, anthracite coal, limestone and peridotite were mixed in a turbo mixer for a duration of about 30 minutes to obtain a homogenous mixture. About 6% to 9% of water was added to the homogenous mixture (composition). Pellets were prepared by using balling disc (pelletizer) During pelletizing, the green pellets were screened with about 10mm and about 12.5 mm sieve to obtain pellet size ranging from about 10 mm to 12.5 mm. The obtained pellets were subjected to heating in induration furnace at a temperature of about 1300 ºC for a duration of about 3 minutes to obtain iron ore pellets.

Table 1 describes the chemical analysis of the iron ore fines, limestone, bentonite, anthracite coal and peridotite.

Constituents, wt.% Iron ore Bentonite Limestone Peridotite Anthracite Coal
Fe(t) 61.25 9.72 - 6.51 0.65
SiO2 4.33 45.97 1.55 32.23 5.2
Al2O3 3.91 14.49 0.31 0.34 2.21
CaO 0.04 1.78 53.01 0.98 0.15
MgO 0.01 2.24 0.43 41.66 0.14
LOI 3.24 17.6 43.56 14.23 -
Fixed carbon - - - 86.37
Table 1:

Table 2 describes the particle size distribution of the iron ore fines, bentonite, peridotite, limestone and anthracite coal.
Size range (µm) Iron ore Bentonite Peridotite Limestone Coal
+150 7.4 19.8 8.6 19.0 18.1
-150+74 4.8 7.7 7.0 5.0 8.4
-74+63 5.7 7.7 6.4 2.9 7.2
-63+45 10.9 17.9 7.6 2.9 7.8
-45+37 3.8 9.3 7.3 2.1 6.8
-37 67.4 37.7 63.1 68.1 51.7

Table 2:
Table 3 describes comparison between the iron ore pellet of the present disclosure (comprising peridotite as MgO source) and the conventional iron ore pellet (comprising olivine as MgO source)
Pellets with Olivine as MgO source (conventional) Pellets with peridotite as MgO source (present disclosure)
Fe, % 61.23 61.52
CaO, % 1.28 1.31
SiO2, % 4.38 4.56
MgO, % 1.8 1.8
Al2O3, % 2.9 2.56
Mean size, mm 11.62 12.23
CCS Avg. (Kg/pellet) 216 214
RI(%) 72.12 73.41
SI (%) 15.58 15.32
HOSIM time (min) 156 141
Porosity (%) 23.4 27.2
Table 3:
Following are the inference from the data of Table 3-
- The iron ore pellet of the present disclosure has higher CaO percentage when compared to conventional iron ore pellet. Higher CaO content provides improved slag bonds such as calcium silicate bonds and provides improved strength and decreases swelling index.
- The iron ore pellet of the present disclosure has higher SiO2 percentage when compared to conventional iron ore pellet. Higher SiO2 content provides improved slag bonds that arrests swelling index and provides improved strength.
- The iron ore pellet of the present disclosure has lower alumina content when compared to conventional iron ore pellet. Lower alumina content of the ore pellet leads to lower slag rate and higher productivity when used in blast furnace.
- The iron ore pellet of the present disclosure has higher Fe (T) content when compared to conventional iron ore pellet. Higher Fe (T) content in iron ore pellet increases the productivity in blast furnace.
- The iron ore pellet of the present disclosure has higher reducibility index when compared to conventional iron ore pellet. Higher reducibility index leads to higher reductivity and lower carbon rates during application in blast furnace, as a result increases productivity.
- The iron ore pellet of the present disclosure has lower swelling index when compared to conventional iron ore pellet. Lower swelling index is attributed to higher Cao and higher SiO2 contents in the pellet. Lower swelling index improves the productivity upon application of the iron ore pellet in blast furnace.
- The iron ore pellet of the present disclosure has lower HOSIM time when compared to conventional iron ore pellet. Lower the HOSIM time means higher reducibility and takes lesser time to reduce the pellets when used in blast furnace.
- The iron ore pellet of the present disclosure has higher porosity when compared to conventional iron ore pellet. Higher porosity leads to higher reducibility.
- The iron ore pellet of the present disclosure has higher mean size when compared to conventional iron ore pellet. Higher mean size provides for improved permeability when used in blast furnace.

Figure 1 illustrates the optical image of iron ore pellets of the present disclosure. The image clearly shows side silicate bonds and Magnesio ferrite bonds.

The advantage of using peridotite (as a source of MgO and SiO2) in preparing the iron ore pellet of the present disclosure is that during heating (induration), it forms Magnesio ferrite and silicate bonds thereby providing improved pellet properties, suitable for use in blast furnace. The Magnesio ferrite bonds are evenly distributed in between iron ore particles (illustrated in Figure 1).
Further, the use of peridotite enables decrease in flux cost for pellet making when compared to the cost involved in making conventional iron ore pellet.