Claims:We Claim:

1.Solid fuel composition for iron ore sintering for synergistically improved productivity comprising of a combination of partially replaced coke breeze as solid fuel by heat altered coal (Jhama Coal) alongwith the rest being coke breeze fines.
2.The solid fuel composition as claimed in claim 1 wherein with 5% increment in said heat altered coal (Jhama ) replacement ratio, specific productivity is increasing upto 20% replacement and providing flame front movement faster in 20% replacement ratio, facilitated by Jhama content having higher VM adapted for early ignition and at lower temperature than coke breeze.
3. The solid fuel composition as claimed in anyone of claims 1 or 2 comprising 20% Jharma replacement providing maximum 10-25 mm sinter.
4. The solid fuel composition as claimed in anyone of claims 1 to 3 wherein having Jhama replacement upto 20% with RDI data almost stable at ~18%,
5. The solid fuel composition as claimed in anyone of claims 1 to 4 comprises of 20-30% of the heat altered coal (Jhama coal) and remainder being the coke breeze fines.
6. The solid fuel composition as claimed in anyone of claims 1 to 5 wherein particle size of heat altered coal (Jhama coal) and the coke breeze fines ranges from 0.25 mm to 3.15 mm.
7. The solid fuel composition as claimed in anyone of claims 1 to 6 comprising upto 20% replacement ratio of heat altered coal (Jhama coal) providing increase selectively of (i) the RI value increased (ii) sinter porosity increase and (iii) sinter productivity increase.

8. A process for iron ore sintering involving the solid fuel composition as claimed in anyone of claims 1 to 7 comprising
carrying out said process of sintering involving solid fuel sourced from a solid fuel composition for improved synergistically productivity comprising of a combination of partially replaced coke breeze as solid fuel by heat altered coal (Jhama Coal) alongwith the rest coke breeze fines.

9.The process as claimed in claim 8 which is carried out with 5% increment in said heat altered coal (Jhama ) replacement ratio, whereby specific productivity is increased upto 20% replacement and providing flame front movement faster in 20% replacement ratio, facilitated by Jhama content having higher VM adapted for early ignition and at lower temperature than coke breeze and wherein involving 20% Jhama replacement for maximum 10-25 mm sinter with RDI data almost stable at ~18% and also providing increase selectively of (i) the RI value increased (ii) sinter porosity increase and (iii) sinter productivity increase.

10. The process as claimed in anyone of claims 8 or 9 wherein said solid fuel composition used comprises of 20-30% of the heat altered coal (Jhama coal) and remainder being the coke breeze fines and wherein particle size of heat altered coal (Jhama coal) and the coke breeze fines ranges from 0.25 mm to 3.15 mm.

Dated this the 23rd day of March, 2022
Anjan Sen
Of Anjan Sen & Associates
(Applicant’s Agent)
IN/PA-199
, Description:FORM 2
THE PATENT ACT 1970
(39 OF 1970)
&
The Patent Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

1 TITLE OF THE INVENTION :
A PROCESS OF UTILIZING HEAT ALTERED COAL AS SOLID FUEL IN IRON ORE SINTERING.



2 APPLICANT (S)

Name : STEEL AUTHORITY OF INDIA LIMITED.

Nationality : Indian.

Address : Research & Development Centre for Iron & Steel,
Doranda, Ranchi, Jharkhand, India. PIN-834002.






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 INVENTION:

The present invention relates to solid fuel composition comprising of a combination of partially replaced coke breeze as solid fuel by heat altered coal (Jhama Coal) alongwith the rest being coke breeze fines for iron ore sintering for synergistically improved productivity and a process thereof.

BACKGROUND OF INVENTION:

Around 80% of the heat required in sintering is supplied by the combustion of solid fuel. The solid fuels used in sintering are primarily coke and, in some cases, anthracite, with each having different thermal effects depending on the chemistry (carbon content) and the combustion efficiency. The main combustible constituent of coke, used as a solid fuel in sintering, is carbon. As coke accounts for only 4–5 wt.% of the sinter mix, a small change in its properties (reactivity, size, and ash content) can have a large effect on the combustion behavior, heat generation, and sintering performance The combustion behavior of solid fuel in the sintering bed along with the velocity of the descending gas (through the bed) determines the temperature, width, and speed of the transverse flame front, which in turn influences the quality of sinter, its yield, and productivity.

Coal affected by igneous intrusion is a common phenomenon and the heat altered coals are commonly known as Jhama coal in Indian context. The kind of coal alteration depends on the temperature of the intrusion, the duration of magmatic heating and the distance of coal from direct contact with the igneous rock. Thermo-contact transformation, as a result of the igneous intrusion, resulted in a significant change in physico-mechanical properties of a coal seam. It has been found that volatile matter and total hydrogen decrease towards the contact zone, while ash, total carbon and vitrinite reflectance all steadily increase. The volatile matter and ultimate analysis characteristics of the highly affected coals indicate that it is more like semi-coke, rather than a completely carbonized product. The occurrence of mosaic structure is one of the primary features which distinguish heat altered coal from natural char.

Jhama coal is available in plenty, in SAIL Ramnagore colliery. However, there is no process is gainful utilization of this natural resource in any steel plant. Presently this Jhama coal is sold to sponge iron manufacturers for DR process. On the contrary, Sinter plants of many SAIL plants suffer due to insufficient availability of coke breeze, the primary solid fuel for sintering.

Under the present invention RDCIS ,, R&D department of the applicant envisaged to use Jhama coal as partial replacement of coke breeze and to solve the coke breeze crisis as well as establishing a route for gainful utilization of this natural resource.

OBJECTIVE OF THE INVENTION:

The basic object of the present invention is directed to use of naturally occurring heat altered coal as solid fuel in iron ore sinter making to substitute some part of scarce coke breeze.

A further object of the present invention is directed to reduce consumption of costly coke breeze by partial replacement with low cost heat altered coal or Jhama coal available in plenty as solid fuel in iron ore sintering.

A still further object of the present invention is directed to utilize heat altered coal as solid fuel in sintering process along with coke breeze fine so as to synergistically improved sinter productivity.

SUMMARY OF THE INVENTION:

The basic aspect of the present invention is directed to solid fuel composition for iron ore sintering for synergistically improved productivity comprising of a combination of partially replaced coke breeze as solid fuel by heat altered coal (Jhama Coal) alongwith the rest being coke breeze fines.
A further aspect of the present invention is directed to said solid fuel composition wherein with 5% increment in said heat altered coal (Jhama) replacement ratio, specific productivity is increasing upto 20% replacement and providing flame front movement faster in 20% replacement ratio, facilitated by Jhama content having higher VM adapted for early ignition and at lower temperature than coke breeze.

A still further aspect of the present invention is directed to said solid fuel composition comprising 20% Jharma replacement providing maximum 10-25 mm sinter.

A still further aspect of the present invention is directed to said solid fuel composition wherein having Jhama replacement upto 20% with RDI data almost stable at ~18%,

A still further aspect of the present invention is directed to said solid fuel composition as claimed in anyone of claims 1 to 4 comprises of 20-30% of the heat altered coal (Jhama coal) and remainder being the coke breeze fines.

Another aspect of the present invention is directed to said solid fuel composition wherein particle size of heat altered coal (Jhama coal) and the coke breeze fines ranges from 0.25 mm to 3.15 mm.

Yet another aspect of the present invention is directed to said solid fuel composition comprising upto 20% replacement ratio of heat altered coal (Jhama coal) providing increase selectively of (i) the RI value increased (ii) sinter porosity increase and (iii) sinter productivity increase.
A further aspect of the present invention is directed to a process for iron ore sintering involving the solid fuel composition as described above comprising
carrying out said process of sintering involving solid fuel sourced from a solid fuel composition for improved synergistically productivity comprising of a combination of partially replaced coke breeze as solid fuel by heat altered coal (Jhama Coal) alongwith the rest coke breeze fines.
A still further aspect of the present invention is directed to said process which is carried out with 5% increment in said heat altered coal (Jhama ) replacement ratio, whereby specific productivity is increased upto 20% replacement and providing flame front movement faster in 20% replacement ratio, facilitated by Jhama content having higher VM adapted for early ignition and at lower temperature than coke breeze and wherein involving 20% Jhama replacement for maximum 10-25 mm sinter with RDI data almost stable at ~18% and also providing increase selectively of (i) the RI value increased (ii) sinter porosity increase and (iii) sinter productivity increase.
A still further aspect of the present invention is directed to said process wherein said solid fuel composition used comprises of 20-30% of the heat altered coal (Jhama coal) and remainder being the coke breeze fines and wherein particle size of heat altered coal (Jhama coal) and the coke breeze fines ranges from 0.25 mm to 3.15 mm.
The above and other aspects 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 DRAWING

Figure 1: shows a graphical plot to show the incresase in (a) specific productivity and (b) TI, (c) porosity, of sinter with increased proportion of Jhama by increment of 5% replacing coke breeze in iron ore sintering.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO ACCOMPANYING DRAWING:

The present invention is directed to use of naturally occurring heat altered coal or Jhama coal as solid fuel in iron ore sinter making to substitute some part of scarce coke breeze.

Jhama collected from all three faces namely Duburdih, Laikdih and Salanpur C of Ramnagore Colliery, SAIL and detailed characterization studies conducted. Volatile matter varies from 4.0 to 7.7, ash varies from 33.1 to 25.0, fixed carbon varies from 61.4 to 68.9. From ultimate analysis it is seen that, order of total carbon present is coke breeze>Laikdih>Duburdh>Salanpur C.

It is apparent from Figure 1(a-c) that highest specific productivity is achieved at 20% Jhama replacement. With 5% increment in Jhama replacement ratio, specific productivity is increasing upto 20% replacement, afterwards the curve starts decreasing. Flame front moves faster in 20% replacement ratio, as Jhama having higher VM ignites earlier and at lower temperature than coke breeze. With increased replacement of Jhama, yield is increased steadily till the critical point of 20% replacement. Afterwards, yield drops steeply. Specific VM load increase from 0.627 to 1.516 with increased replacement ratio from 0 to 35%. The slope of increase is very steep beyond 30% replacement ratio. Specific ash load increased from 9.868 to 12.438, with increasing replacement from 0% to 35%

Sinter produced with 20% Jhama replacement produced maximum 10-25 mm sinter. With increasing Jhama replacement, sinter return generation reduced gradually. Maximum T.I. is achieved with 20% replacement ratio, after which point more the replacement, lesser is the T.I. Total porosity gradually increased with increased replacement, as VM increased with increased replacement. For increased replacement from 20% to 25%, population of 200-500 micron pores increased substantially whereas that of -100 micron pores decreases drastically. For Jhama replacement upto 20% RDI data is almost stable at ~18%, for 25% replacement RDI is deteriorated to 25.1. RI data proves that, 25% replacement sinter produce most redouble sinter with RI of 62.1. this is shown in following Table 1.

Salient advantageous features of the present invention are as follows:
The lower availability of coke breeze for sintering has compelled many a researchers worldwide to search for various alternative fuels those can partially replace coke breeze in sintering. Besides, from environmental perspective too, alternative fuels have been researched for use in sinter making.

Alternate fuels e.g. charcoal, straw char, biomass etc. have been successfully tried as solid fuel in sintering. Specifically in Indian context, CPC, RPC, Anthracite coal have been tried as sintering solid fuel. However, present invention ensure following benefit attributes:

• Heat altered coal (Jhama coal) is for the first time used as solid fuel in iron ore sintering, replacing coke breeze partly.
• Complete characterization of Heat altered coal (Jhama coal) has been done for the first time.
• Process route for using Heat altered coal (Jhama coal) with conventional coke breeze developed.
• Jhama coal has higher porosity and VM value than coke breeze, which gives certain benefits in sintering process, upto a limited replacement ratio. The optimum replacement ratio is experimentally established.
• High VM increase emission load in exhauster outlet. The increased emission load has been experimentally established, and optimum ratio of replacement finalized.
• Sinter produced with Heat altered coal (Jhama coal) has been characterized completely. Various metallurgical, thermal physical and 3D characterization of sinter produced with Heat altered coal (Jhama coal) completed first time.

Industrial Applicability:
Presently all SAIL plants use only coke breeze, either produced in-plant or transported on IPT basis from sister units as solid fuel in sintering. Technologically, Jhama coal can only partially replace coke breeze for sinter making in every SAIL plant as well as non-SAIL plants. It is thus possible by way of the present invention that Jhama coal (upto 20%) can be used as part replacement of coke breeze in iron ore sintering process with significant advantages in productivity and quality.