Claims:We Claim:
1. A process for sintering of iron ore blend comprising:
subjecting iron ore blend to a step of pre-processing to treat the porous iron ore to fill its pores and/or surface coat the iron ore blend with pore sealing additive/flux to provide the iron ore blend with additive/flux sealed pores and/or thus additive/flux surface coated to enhance the reaction kinetics of iron ores, inhibit absorption of water into the porous ores and espousal to early slag formation for sintering purposes.
2. A process as claimed in claim 1 wherein said pore sealing additive/flux used to fill pores and/or coat the iron ore blend is selected from including dolomite, limestone, calcined lime, calcined dolomite, dolochar, olivine, pyroxenite, dunite, iron ore fines preferably calcined lime which is subsequently involved for further agglomerating sinter raw mixing, granulation and sintering.
3. A process as claimed in anyone of claims 1or 2 wherein said pore sealing additive/flux is selected to fill the pores of the iron ores and inhibit absorption of water into the pores of the porous iron ore and also to act as a binder during granulation and/or during sintering.
4. A process as claimed in anyone of claims 1 to 3 wherein the pre-processing step involving select pore sealing additive/flux is carried out for improving the inter particle adhesion of iron ore with water during granulation step.
5. A process as claimed in anyone of claims 1 to 4 wherein the pre-processing step comprises altering the properties, such as the surface properties, of the iron ores.
6. A process as claimed in anyone of claims 1 to 5 wherein the size fractions are below 1 mm.
7. A process as claimed in anyone of claims 1 to 6 wherein the pre-processing step comprises of addition of said pore sealing additive/flux and / or pre-coating the iron ore particles with pore sealing additive/flux prior to use in further sinter raw mixing, granulation and sintering.
8. A process as claimed in anyone of claims 1 to 7 wherein the pre-processing step comprises adding the pore sealing additive/flux in solid or liquid forms to the ore blend at ore loading or discharge Ports or in stockpiles.
9. A process as claimed in anyone of claims 1 to 8 comprising step of sealing/coating the said porous iron ore with calcined lime whereby the CaO first reacts with hematite to form calcium ferrite which turns to silico ferrite of calcium and aluminium latter on through diffusion of silica and alumina at high temperature in the range of 1100°C to 1300°C to generate complex slag to impart more strength to the sinter with respect to usual diffusion bonding.
10. A process as claimed in anyone of claims 1 to 9 wherein said sealing/coating additive comprise CaO sourced from sinter flux materials including limestone and calcined/burnt lime.
11. A process as claimed in anyone of claims 1 to 10 wherein prior to dry mixing of all sinter raw mix in the drum mixer, firstly, the highly porous iron ores are charged along with the calcined lime into the drum mixer for required time to completely homogeneous mix of iron ore and calcined lime, micro voids filling with calcined lime and surface coating of iron ore, thereafter once the said pre processing of iron ore is completed, remaining sinter mix raw material constituents are subsequently added to the drum mixer and mix for given time to complete the homogenization of sinter raw materials, after the dry mixing, wet mixing is carried out in presence of water addition for granulation which is charged for sintering.
12. A process as claimed in anyone of claims 1 to 11 wherein said sinter mix include fluxes including lime stone, dolomite, coal/coke, return fines, calcined lime, mixture of limestone/dolomite/return fines, coal and coke.
13. Sinter obtained by the process as claimed in anyone of claims 1 to 12 involving pores of iron ore filled with reactive CaO preferably calcined lime alongwith other sinter mix and a complex slag based binding of agglomerates which is a reaction product of CaO reaction with hematite to form calcium ferrite which turns to silico ferrite of calcium and aluminium latter on through diffusion of silica and alumina at high temperature in the range of 1100°C to 1300°C.

Dated this the 29th day of November, 2017
Anjan Sen
Of Anjan Sen & Associates
(Applicants Agent)
, Description:FIELD OF THE INVENTION
The present invention relates to a method of sintering of iron ore blend comprising highly porous iron ore involving pre-processing of such porous iron ore to block the pores and prevent water absorption during granulation in mixing and nodulizing drum in presence of water to improve sinter quality and plant productivity. More particularly, the present invention is directed to provide a novel process to deal with high porous iron ore and to achieve better plant productivity and sinter quality by pre-processing with calcined lime (CaO) met by two flux sources, limestone and burnt lime, wherein limestone/burnt lime ratio is optimized to attain maximum production and quality with increased sinter strength, while inhibiting absorption of water into the porous ores. Here, highly porous iron ore from Carajas Mines, Brazil, a high grade iron ore (Fe: ~65%) is used and compared with local (Indian) dense iron ore. In this invention iron ore is pre-processed so that the negative influence of porous nature of iron ore can be neutralized.

BACKGROUND OF THE INVENTION:

During Dwight-Lloyd iron ore sintering process, the agglomeration of iron ore takes place via incipient fusion of iron ore particles in presence of other raw material constituents like limestone, dolomite, calcined lime, sinter return fines and steel plant wastes in presence of thermal energy supplied through combustion of solid fuel includes coke breeze and coal also added as a raw mix constituent. During this process, the temperature at the sintering bed raise up to 1300°C resulting in the formation of slag in presence of flux which bonds the ore particles through diffusion and slag bond to lump particle called iron ore sinter. This sinter cake break and screened to the required size possessing optimum cold strength and reducibility property as desired by blast furnace. Worldwide, sinter is being used as major (60-70%) burden material for blast furnace iron making which puts working pressure on the sinter plant to produce sinter of consistent quality with high productivity.

Though several factors influence the sinter quality and sinter plant productivity, the nature and type of iron ore has major impact on it. It is reported in literature that the goethite, limonite, hematite and magnetite content impacts the agglomeration behavior differently. The physical nature of iron ore like porous/dense structure also influences the sinter quality and sinter plant productivity. During sintering, the reaction kinetics of porous iron ore slows down as compared to the denser iron ore owing to the large surface area available and increased melt volume reduces high temperature permeability. Consequently, the higher resistance to downdraft air flow and air filtration velocity increase the sintering time. So, the sinter plant productivity is adversely affected with the increased fractions of porous iron ore in iron ore blend. The significant reduction in sinter plant productivity is also reported in earlier studies [“Sintering iron ore blends containing Yandi pisolitic limonite using coarser fluxes”; 6th International Symposium on Agglomeration, 1993, pp. 267-272, and "Improving sintering performance of ore blends containing pisolite ore; Trans. Inst. Min. Metall. (Sec. C: Mineral Processing Extra. Metall) 103, May-August 1994]. They explained that the observed reduction in sinter plant productivity is due to soft/porous ores absorbing a significant proportion of the water added during the granulation process which would otherwise be available for inter-particle adhesion. Specifically, the increased water absorption causes a reduction in green bed permeability. In various different report, researchers have reported improvement in sinter plant productivity by blending the porous pisolite ore with the dense hematite ore. Japanese Patent 58-55221 entitled "Method of Pre-processing Sinter Raw Materials" in the name of Nippon Steel Corporation and Nisshin Steel Technical Report 1988, December, No. 59, 68-75 entitled "Increase of Sinter Productivity by Pre-granulation Process" proposed serpentine coating of the pisolite iron ore surface before granulation with other components to form a green mix. Further, Japanese patent 58-141341 entitled "Preliminary Treating of Ore containing limonite for Sintering" in the name of Nippon Steel Corp. proposed coating the surface of particles of pisolite ores with fine ores (greater than 80% of the fine ore particles less than 0.25 mm) prior to granulation with other components to form a green mix. The coated pisolite iron ore either with serpentine or fine ore is expected to alter the assimilation reaction of the ore particles during sintering and thereby improve sinter plant productivity.

Further, it was proposed to increase the water molecules during sintering so that the water requirement of the porous ore for granulation can be achieved with better granules. [“Plant sintering performance with high proportion of pisolitic limonite ore" 6th International Symposium on Agglomeration 1993 pgs. 255-260, and "Operation with high blending ratio of pisolite ore at Kobe Works" 1st Int. Congr. on Sci. and Tech. of Ironmaking 1994]. As pisolite iron ore is a goethitic type of ore already containing significant water, it may not be favorable to the sinter plant. In general, increased water content in the green mix causes a lowering of exhaust gas temperatures, increased fan load, and possibly, condensation in the wind legs and deterioration in electrostatic precipitator performance. Increased water addition may result in moisture condensation zone at the lower bed during sintering which could have an adverse effect on the bed-permeability and the airflow distribution through the bed during sintering.

Patent publication No: WO 1996001333-A1 entitled “Sintering an iron ore blend containing porous ores” mentions the investigation with three different porous iron ores collected from different regions which include (a) pisolite ore, such as Yandi ore, which is composed predominantly of goethite (FeO.OH) with only minor amounts of hematite; (b) porous hematite ores, such as from certain parts of the Carajas mine in Brazil; and (c) hematite-goethite ores such as Marra Mamba ore. In this invention, inventors proposed a treatment step by adding additives to alter the surface behavior of ore and inhibit absorption of water into the porous ores.

In the present invention, a new and novel process is developed to deal with such type of high porous iron ore and to achieve better plant productivity and sinter quality without using the above mentioned additives. Here, highly porous iron ore from Carajas Mines, Brazil, a high grade iron ore (Fe: ~65%) is used and compared with local (Indian) dense iron ore. In this invention iron ore is pre-processed so that the negative influence of porous nature of iron ore can be neutralized.

Brief description of the conventional sintering process:
In conventional sintering process, the raw material mixture (iron ore fines, solid fuel (coke breeze/coal), limestone, dolomite, calcined/burnt lime, sinter return fines etc.) is mixed thoroughly in a drum in absence of water for stipulated period, called dry mixing. This dry mix is further mixed in presence of water in a rotary drum for specified period for the formation of green ball under granulation. During granulation, intermediate and fine particles get coated over the coarser particles through inter-particle adhesion via water bridges, whereby larger granules or quasi-particles form that are larger in size and closer in size range than the original feed. Water plays an important role during granulation in mixing and nodulizing drum forms an interface between the finer and coarser iron ore particles during granulation to form relatively bigger granules. It promotes the adhering characteristics of iron ore fines and fluxes so that the bigger granules improve the bed permeability at sinter strand which in turn enhance the productivity of process and properties of sinter. In addition to the above, the bigger granules subsequently results in homogeneous burning as well as uniform suction during sintering. It also reduces the loss of valuable fines during suction of sintering. The sinter mixes on the strand are burnt from the top. The suction of air through the bed helps sustaining the combustion of the fuel and provides the downward movement of the combustion zone through the bed up to the bottom layer to raise the temperature to 1250-1300 ºC. During the process of sintering the granulated materials undergo incipient fusion.
Sintering of Porous Iron ore through conventional route:
Sinter mix preparation for the porous iron ore were performed as per the methodology adopted in conventional sintering process described above. The water requirement for porous iron ore is higher as under capillary action it enters into micro-pores of porous iron ores causing less surface water availability and demands extra water for optimum granulation. During sintering, under drying zone of the sinter bed, water from the micro pores vaporize and travels through downdraft suction to the lower bed where it gets condensed which not only reduces the bed temperature but also disturbs the sinter bed permeability. As a consequence the sintering reaction kinetics deteriorates and increases the overall sintering time and reduces the sinter plant productivity. Water evaporation from micro-pores of iron ore during sintering causes crack generation and increases the availability of free surface area for the reaction. During sintering of this kind of ore, the low melting slag enters into the pores and cracks resulting in generation of thick melt volume which retards the air filtration velocity and consequently the plant productivity. The filling of the pores can be achieved through temporary closure of the pores of iron ore prior to granulation in presence of water. The pore filler should also have the adherence quality and reactive to form a low viscous primary slag.

A new method of pre-processing of iron ore has been designed which can overcome the disadvantages of blocking of micro-pores of iron ore with water molecules during conventional granulation method as well as ensuring rich formation of calcium ferrite phases during initial phase of sintering which is expected to give better strength to the sinter. Further, increased solid fuel demand arises for removal of excess water. All these factors can be taken care of by adopting the new granulation method.

OBJECTS OF THE INVENTION:

The basic object of the present invention is directed to a process for sintering of iron ore blend for effective utilization of highly porous iron ores in sinter making for improved sinter quality and plant productivity.

A further object of the present invention is directed to a process of sintering iron ore blend including highly porous iron ore involving a step of pre-processing of such porous iron ore to block the pores and prevent water absorption during granulation in mixing and nodulizing drum.

A still further object of the present invention is directed to a process of sintering highly porous iron ore involving said step of pre-processing wherein the highly porous iron ores are charged along with the calcined lime into the drum mixer for required time to completely homogeneous mix of iron ore and calcined lime, micro voids filling with calcined lime and surface coating of iron ore, prior to mixing with other ingredients, to inhibit water absorption during subsequent wet mixing and granulation in presence of water.

A still further object of the present invention is directed to a process of sintering highly porous iron ore involving said step of pre-processing with calcined lime ensuring rich formation of calcium ferrite phases during initial phase of sintering which is expected to give better strength to the sinter with reduced sintering time.

A still further object of the present invention is directed to a process of sintering highly porous iron ore involving said step of pre-processing with calcined lime wherein optimized limestone/burnt lime ratio is used to attain maximum production and quality.

SUMMARY OF THE INVENTION

The basic aspect of the present invention is directed to a process for sintering of iron ore blend comprising:
subjecting iron ore blend to a step of pre-processing to treat the porous iron ore to fill its pores and/or surface coat the iron ore blend with pore sealing additive/flux to provide the iron ore blend with additive/flux sealed pores and/or thus additive/flux surface coated to enhance the reaction kinetics of iron ores, inhibit absorption of water into the porous ores and espousal to early slag formation for sintering purposes.
A further aspect of the present invention is directed to a process wherein said pore sealing additive/flux used to fill pores and/or coat the iron ore blend is selected from including dolomite, limestone, calcined lime, calcined dolomite, dolochar, olivine, pyroxenite, dunite, iron ore fines preferably calcined lime which is subsequently involved for further agglomerating sinter raw mixing, granulation and sintering.
A still further aspect of the present invention is directed to said process wherein said pore sealing additive/flux is selected to fill the pores of the iron ores and inhibit absorption of water into the pores of the porous iron ore and also to act as a binder during granulation and/or during sintering.
Another aspect of the present invention is directed to said process wherein the pre-processing step involving select pore sealing additive/flux is carried out for improving the inter particle adhesion of iron ore with water during granulation step.
Yet another aspect of the present invention is directed to said process wherein the pre-processing step comprises altering the properties, such as the surface properties, of the iron ores.
A further aspect of the present invention is directed to said process wherein the size fractions are below 1 mm.
A still further aspect of the present invention is directed to said process wherein the pre-processing step comprises of addition of said pore sealing additive/flux and / or pre-coating the iron ore particles with pore sealing additive/flux prior to use in further sinter raw mixing, granulation and sintering.
A still further aspect of the present invention is directed to said process wherein the pre-processing step comprises adding the pore sealing additive/flux in solid or liquid forms to the ore blend at ore loading or discharge Ports or in stockpiles.
A still further aspect of the present invention is directed to said process comprising step of sealing/coating the said porous iron ore with calcined lime whereby the CaO first reacts with hematite to form calcium ferrite which turns to silico ferrite of calcium and aluminium latter on through diffusion of silica and alumina at high temperature in the range of 1100°C to 1300°C to generate complex slag to impart more strength to the sinter with respect to usual diffusion bonding.
Another aspect of the present invention is directed to said process wherein said sealing/coating additive comprise CaO sourced from sinter flux materials including limestone and burnt lime.
Yet another aspect of the present invention is directed to said process wherein prior to dry mixing of all sinter raw mix in the drum mixer, firstly, the highly porous iron ores are charged along with the calcined lime into the drum mixer for required time to completely homogeneous mix of iron ore and calcined lime, micro voids filling with calcined lime and surface coating of iron ore, thereafter once the said pre processing of iron ore is completed, remaining sinter mix raw material constituents are subsequently added to the drum mixer and mix for given time to complete the homogenization of sinter raw materials, after the dry mixing, wet mixing is carried out in presence of water addition for granulation which is charged for sintering.
A further aspect of the present invention is directed to said process wherein said sinter mix includes fluxes including limestone, dolomite, coal/coke, return fines, calcined lime, mixture of limestone/dolomite/return fines, coal and coke.
A still further aspect of the present invention is directed to Sinter obtained by the process involving pores of iron ore filled with reactive CaO preferably calcined lime alongwith other sinter mix and a complex slag based binding of agglomerates which is a reaction product of CaO reaction with hematite to form calcium ferrite which turns to silico ferrite of calcium and aluminium latter on through diffusion of silica and alumina at high temperature in the range of 1100°C to 1300°C .

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 schematically the apparatus and method for the dry mixing of raw materials in conventional sintering process.
Figure 2: shows schematically the Granulation Process for Sintering of porous iron ore according to present invention involving a pre-processing step.
Figure 3: Pictorial representation of the conventional sintering process for porous iron ore.

Figure 4: Pictorial representation of the sintering process for porous iron ore according to present invention.

Figure 5: shows graphically the improvement in tumbler index of sinter obtained from porous iron ore (Carajas) produced by the process according to present invention as compared to conventional process.

Figure 6: shows graphically the reduction in sintering time for producing agglomerates from porous iron ore (Carajas) by the process according to present invention as compared to conventional process.

Figure 7: shows graphically the improvement in tumbler index of sinter obtained from Orissa iron ore (dense structure) produced by the process according to present invention as compared to conventional process.

Figure 8: shows graphically the reduction in sintering time for producing agglomerates from Orissa iron ore (dense structure) produced by the process according to present invention as compared to conventional process.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO ACCOMPANYING DRAWINGS
The present invention is directed to a process for sintering of iron ore blend comprising highly porous iron ore for effective utilization of highly porous iron ores in sinter making for improved sinter quality and plant productivity. The pre-processing step involves dry mixing of porous iron ore and calcined lime (CaO) wherein the highly porous iron ores are charged along with the calcined lime into the drum mixer for required time to achieve completely homogeneous mix of iron ore and calcined lime, micro voids filling with calcined lime and surface coating of iron ore, prior to mixing with other ingredients to inhibit water absorption during subsequent wet mixing and granulation in presence of water.
In the present invention, the micro-pores of highly porous iron ore are sealed with calcined lime (CaO), one of the raw sinter mix constituent generally added to fulfill the binder requirement and CaO content for basic and super fluxed sinter preparation. CaO helps in easy slag formation as well as reducing the dependency of direct limestone charging to blast furnace which in turn demands more fuel rate for its calcinations. Also in sinter making, the CaO helps to form more slag bonding i.e. CaO first reacts with hematite to form calcium ferrite which turns to silico ferrite of calcium and aluminium latter on through diffusion of silica and alumina at high temperature. This complex slag provides more strength to the sinter as compared to diffusion bonding and its proportion increases with increase in calcium ferrite formation in the early stage of sintering. This CaO required in sinter making is met by two flux sources; limestone and burnt lime. The limestone needs heat for its calcinations which is not in case of burnt lime. But the whole limestone cannot be replaced by burnt lime as burnt lime affects the sinter bed permeability which is a major factors affecting sinter productivity. Thus optimized limestone/burnt lime ratio is used to attain maximum production and quality.

In the present work, prior to dry mixing of whole sinter raw mix in the drum mixer, firstly, the highly porous iron ores are charged along with the calcined lime into the drum mixer for required time to completely homogeneous mix of iron ore and calcined lime, micro voids filling with calcined lime and surface coating of iron ore. Once the pre processing of iron ore is completed, remaining raw material constituents are subsequently added to the drum mixer and mix for given time to complete the homogenization of sinter raw materials. After the dry mixing, wet mixing is carried out in presence of water addition for granulation which is charged for sintering.

A pictorial comparison between conventional and new granulation method is given in accompanying figure 1 & 2.

Conventional granulation methods (Dry mixing)
Figure 1 shows the the dry mixing of raw materials in conventional sintering process. After dry mixing all the materials are mixed homegeneously where the nucleus iron ore particles are coated either with finer fractions of iron ore, limestone, dolomite, solid fuel etc as pictorially represented in Figure 1. Discrete particles of iron ore would also present alongwith the neighbour fluxes and solid fuel.

New granulation method (Dry mixing)
Figure 2 shows the new granulation method where iron ore is pre-processed with calcined lime in rotary drum. The lime coated iron ore particles are mixed with other ingredients where they form a layer on lime coated ore.

Sintering of Porous iron ore
(a) Conventional sintering process:
The pictorial representation explains the mechanism of sintering process of porous iron ore under conventional route. It is clear from Figure 1 that once the water is added to granulate the raw materials after dry mixing, it enters into the micro-pores of iron ore which vaporize during sintering and forms micro voids causing the delay in void filling results in formation of thick slag melt volume.

(b) New sintering process:
In the proposed pre-processing of iron ore methodology, calcined lime temporarily fills the pores and coat over the iron ore surface which helps in less water adsorption and early slag formation resulting in significant improvement in sinter quality and plant productivity.
The features of the sintering process according to present invention using highly porous iron ore vis-à-vis dense iron ore are described hereunder with reference to following illustrative example:

Example I:

? Approximately 90 kg of sinter mix blended using balling drum. Blending condition: mixing @ 20 rpm for 300 seconds.
? One kg of each blended sinter mix sample was dried and analyzed for particle size distribution.
? Agglomerated the sinter mix in presence of moisture using a drum mixer; Agglomerating condition: mixing @ 20 rpm for 480 seconds.
? Sintered the material in pot grate with ignition conditions as under:
Ignition conditions:
Suction air flow volume before ignition 2.0 m3/min
Ignition holding time 60 sec
Suction pressure after ignition -1200 mm H2O

• Raw materials were screened to obtain the desired size as given below.
Material Size
Base Mix As received
Calcined lime - 0.212 mm
Coke breeze - 3.15 mm

• Two types of green mix preparation i.e. granulation process
(i) Conventional granulation process: All the individual raw materials added simultaneously to the drum mixer. It is dry mixed and then wet mixed to obtained granules.
(ii) New granulation process: Drum mixer is first charged with iron ores and then calcined lime is added immediately above the iron ores and then dry mixed for a period of 60-120 seconds. After then remaining raw materials are added into the drum mixer. Then whole batch is first dry mixed and then wet mixed to obtained granules.

• Two types of sinter mix were prepared by both granulation process (i.e. conventional & new granulation process) at two different Basicity ((CaO/SiO2): 2.2 & 3.2)
(i) Sinter Mix (with highly porous Carajas iron ore)
(ii) Sinter Mix (with dense Orissa iron ore)
• Bed Height: 700 mm (constant), Hearth Layer: 60 mm

The high porous iron ore (Carajas iron ore) has the porosity value greater than 15%. Whereas, dense iron ore (Orissa iron ore) has the porosity value lesser than 7%.

Table-1:Sinter Mix Composition used for the experimental trials:

Table-2: Chemical Analysis of Raw Materials:

The comparative data of sinter strength to show the improvement by way of the process of the present invention over conventional process is presented in following Table 3.

Table-3: Comparative sinter strength data for sinter mix composition experiment 1-8 as in Table 1.
EXPERIMENT IRON ORE MIXED WITH C.LIME Normal mix
1 2 3 4 5 6 7 8
High Porous I/O Dense I/O High porous I/O Dense I/O
Tumbler Index (+6.3mm, %) 79.28 74 72.2 73.5 75.27 71.33 70 72
Sintering Time, min 25.2 23.4 22.1 23.3 26 25 23 25
Productivity (+5mm) (t/m2/h) 2.30 2.39 2.41 2.31 2.23 2.23 2.31 2.16

Exp. 1: Porous Iron ore having higher fraction of limestone (as mentioned in the Table) to achieve higher CaO in sinter and consequently the higher B2 (ratio of CaO/SiO2):3.2
Exp. 2: Porous Iron ore having lower fraction of limestone (as mentioned in the Table) than Exp 1 to achieve lower CaO in sinter and consequently the lower B2 (ratio of CaO/SiO2 of product sinter) of 2.2.
(Note: Both the B2 are of the higher side and considered as super fluxed sinter due to higher CaO content)
Exp. 3: Dense Iron ore having lower fraction of limestone (as mentioned in the Table) to achieve lower CaO in sinter and consequently the lower B2 (ratio of CaO/SiO2):2.2
Exp. 4: Dense Iron ore having higher fraction of limestone (as mentioned in the Table) than Exp 3 to achieve higher CaO in sinter and consequently the higher B2 (ratio of CaO/SiO2 of product sinter) of 3.2.
{Exp. 5-8: similar experiments as Exp. 1-4 in conventional route}

Results:
Pilot scale laboratory trials carried out using both conventional granulation process as well as new granulation process for both types of iron ore i.e. porous Carajas iron ore and dense Orissa iron ore and results have been depicted in the graphs in accompanying Figures 5-8 which are self-explanatory.