TITLE;
A method of preparing iron-coal briquette or ferro coke from iron ore.
FIELD OF INVENTION
This invention relates to a method of preparing iron-coal briquette or ferro coke from iron ore.
BACKGROUND OF INVENTION
Nowadays the innovative energy saving technologies for reduction of global warming is necessary. Iron making process like sintering, coke making and blast furnace operation are highly energy sensitive process. As countermeasure for burden into a blast furnace recent development has been take place on iron-carbon composites. The composites have few advantages that it gives high ferrous content and enables less slag rate. The other advantage is that due to intimate contact between ore and solid reducing fines and lower porosity, high heat transfer take place. Still there is a scope of work left for forming iron coal briquettes efficiently.
OBJECTS OF THE INVENTION
An object of the present invention is to propose a method of preparing iron coal briquette from iron ore.
Another object of the invention is to propose a methodology for production of coal iron briquette from iron ore and low grade coal using solvent extracted coal.

SUMARRY OF THE INVENTION
In one aspect, the invention provides a method for preparing iron coal briquette using steps of
synthesing a binder from coal and organic solvent, the binder being processed by solvent extraction of coal with N-methyl pyrollidone and co-solvent ethylene di-amine in a ratio of 1:5:1 respectively between 80-90°C, mixing iron ore powder and coal powder in ratio of 2:3 to form a mixture, subjecting the said mixture to briquetting in briquetting press of 28-33 MPa and pyrolyzing the said briquette in an inert atmosphere at 600-700°C.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure X: shows probable structure of the extracted molecule
Figure 1: shows the scheme of production of ferro coke
Figure 2: shows the chemical structure of coal and fragmented molecules
Figure 3: shows probable structure of the extracted molecule
DETAILED DESCRIPTION OF INVENTION
This invention is to production of coal-iron briquette. In this methodology non-coking or low grade coal and hematite iron ore has been used as raw material. For binder solvent extract of non-coking coal has been used. Non-coking coal is first extracted with organic solvent to achieve

low ash. Due to solvent extraction the useful organic part extracted from the low grade coal. It is then mixed with iron ore and coal mixture in definite proportion and briquettes has been prepared by application of pressure. It is then finally cured in furnace and cold compressive strength has been measured.
Synthesis of Binder
The binder is the extraction product of coal and organic solvent. The parent coal ground to pass through 30 mesh size (-595 micron). NMP (N-Methyl Pyrollidone) used as solvent for extraction with small amount of EDA (Ethylene di-amine) as co-solvent. Coal, solvent and co-solvent ratio kept as 1:5:1. Coal is extracted with solvent at around 80-90 °C. After extraction it was taken out and filtered. Concentrated extract is then added in this water. As these solvents are soluble in water, solvents come to water phase. It results in precipitation of coal solids. Thus precipitated coal is then separated from solvent-water solution through filtration. It was washed with water repeatedly with water followed by drying at 100°C for 24 h.
Characterization of raw material
A hematite type of iron ore taken for experiments. Properties of the iron ore is presented in Table 1 in of the embodiment of the invention. A non-coking thermal coal has been used as the main raw material. This coal has been extracted with organic solvent. Organo-refining is the method in
which organic part of the coal extracted out with the organic solvent. The organo-reftning process can be used to upgrade the quality of low grade coal like thermal, washery rejects and middlings, run of mine coal etc. The properties of both parent and extracted coal are presented in Table 2 in of the embodiment of the invention.
Briquetting
After several experimentation the iron ore to coal ratio has been fixed to 2:3. The iron and coal extract was mixed and briquette has been prepared by hydraulic compression machine. The pressure is limited upto 28-33 MPa.
Pyrolysis
The briquette was then pyrolized in a tubular furnace under inert atmosphere up to 600-700°C. The total scheme of reaction was shown in figure 1. The inert atmosphere is of Nitrogen gas.
Measurement of cold compressive strength
Cold compressive strength is the products ability to resist failure under a compressive load. The presence of pores, cavities, etc. helps in local stress concentration. The failure of material leads to generation of fines (such fines are detrimental for BF operation). The amount of fragments depend on the extent of stress subjected and the nature of material. It is measured through an
UTM.
Results
Table 1 present the properties of iron ore used. The properties of parent and extract are presented in table 2.
The binder here is the extraction product of thermal coal. The extraction product mostly contain lower molecular aliphatic chains. Figure 2 present the probable chemical structure of the binder. A small fragmented portion has been separated for the main coal structure during extraction as shown in the figure. Figure 3 shows the micrograph of the binder. It is a clean vitrinite matrix in which small inertinite particles are embedded.
Table 3 present the different combination of additives and raw material used for making briquette and their subsequent cold compressive strength. The binder percentage tried from 5 to 15%. Series of experiments done by keeping binder from 8-12% and finally it is kept at 10%.
It was found that the CCS value of briquette is higher than the cold strength of pellet used in blast furnace.

WE CLAIM:
1. A method for preparing iron coal briquette, the method comprising steps of:
synthesing a binder from coal and organic solvent, the binder being processed by solvent extraction of coal with N-methyl pyrollidone and co-solvent ethylene di-amine in a ratio of 1:5:1 respectively between 80-90°C.
mixing iron ore powder and coal powder in ratio of 2:3 to form a mixture with the binder (9-11 % by wt.),
subjecting the said mixture to briquetting in briquetting press of 28-33 MPa, and pyrolyzing the said briquette in an inert atmosphere at 600-700°C.
2. The method as claimed in claim 1, wherein the said iron ore is hematite.
3. The method as claimed in claim 1, wherein the pressure for briquetting is preferably 30 MPa.
4. The method as claimed in claim 1, wherein the said inert atmosphere is of Nitrogen gas.