Title of Invention	A PROCESS FOR PRODUCING MICRO-PELLETS OF ANTHRACITE COAL
Abstract	The present invention relates to a process for producing micro-pellets of anthracite coal comprising the steps of screening coal, mixing and binding coal fines with lime and water, pelletizing said mixture in a disc pelletizer having an inclined disc angle and sun drying the resultant, micro-pellets thereafter.

Full Text

FORM 2 THE PATENTS ACT 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See Section 10; rule 13) TITLE OF THE INVENTION A PROCESS FOR PRODUCING MICRO-PELLETS OF ANTHRACITE COAL APPLICANTS ESSAR STEEL LIMITED having its registered office at 27 km Surat Hazira Road, Hazira 394 270, Dist: Surat Gujarat, India, an Indian Company INVENTORS Mr Y Venkateswarlu, Dr A K Das, Mr G W Kamath, Mr Ch Khute and Mr Yogesh Singh all Indian Nationals of ESSAR STEEL LIMITED having its registered office at 27 km Surat Hazira Road, Hazira 394 270, Dist: Surat Gujarat, India, an Indian Company PREAMBLE TO THE DESCRIPTION The following complete specification particularly describes the nature of the invention and the manner in which it is to be performed. FIELD OF INVENTION This invention relates to a process for producing micro-pellets of anthracite coal. Micro-pellets of anthracite coal produced by this process are stable and injected into electric arc furnaces (EAF) for steel production. Clogging is prevented and early foaming in the steel making bath is observed. BACKGROUND OF THE INVENTION In DRI-HBI-EAF route of steel making, coal fines are injected into the EAF for various benefits. Anthracite coal fines when injected into electric arc furnace pose clogging and chocking problems due to residual moisture. Drying by conventional method i.e. kiln was not found successful due to excessive fines in the coal. OBJECT OF INVENTION An object of this invention is to produce micro-pellets of anthracite coal which are stable and useful in Electric Arc furnaces without clogging and chocking. Introduction of the micro-pellets according to this invention results in early foaming of slag, prevents radiation losses from the arc into the furnace atmosphere Desulphurization step in steel making is also found to be more effective. BRIEF DESCRIPTION OF INVENTION Two disc pelletizers with an inclined disc are manufactured and used in producing anthracite coal micro-pellets. Inclination, speed of the disc and residence time is determined by the degree of micro-pelletization required. Screened anthracite coal and lime are loaded on the pelletizer driven by electricity. The disc is rotated for a short while until homogeneous mix is produced. A fine spray of water is directed to the disc while the disc is rotating. Pellets are formed due to rolling. 2 1 3 JUL 2009 STATEMENT OF INVENTION This invention relates to a process for producing micro-pellets of anthracite coal comprising the steps of screening coal, mixing and binding coal fines with lime and water, pelletizing said mixture in a disc pelletizer having an inclined disc angle and sun drying the resultant, micro-pellets thereafter. DETAILED DESCRIPTION OF THE INVENTION Anthracite coal fines were screened (-1 mm), mixed with lime (-1 mm) and water. Pellets were formed with hand and dried under the sun. They were found to be strong enough for transportation. Later a cement mixer was used to pelletize a small quantity of coal fines. Water was added as the mixer rotated. The lime particles were found to nucleate first and attracted lime particles preferentially. The size of pellets was large, as the water droplets were large. This experiment concludes that the water droplets shall be tiny, lime needs to be hydrated partially, to prevent it from attracting lime particles. The anthracite (Russian) coal was found to have greater wetting properties and hence preferred for our study. Disc pelletizer was selected for greater surface area and versatility. A disc-pelletizer was manufactured of 50 kg/batch capacity first. It has a provision to adjust the angle of inclination. The angle of inclination plays an important role in a sense that greater angle would let particles fall quickly with reduced cascading action; too low angle results in sticking and sluggish fall. The driving shaft was fitted with a geared motor, whose speed can be varied with a VVVF drive. The speed of the disc is another vital factor that affects the pelletization action. Too low speed results in greater mixing, but stickiness if wet. The speed of the disc was optimized suiting our study and rate of production. The residence time was optimized; too much of dwell time results in growth and larger size pellets, unusable in our study. 3 1 3 JUL 2009 Initial experiments were conducted to optimize amount of lime and water to be added. Best results were obtained with 12% lime and 15% water. The +6 mm particles were eliminated from the coal. -1 mm lime was added and water was sprayed for initial cracking and assimilation. The coal and lime were taken in weighed proportion and charged into the disc. The disc was allowed to rotate at lower speed (8 rpm) for initial intimate mixing. Later the disc was rotated at 11 rpm, while the fine mist of water was being added by specially made nozzles, held over the disc. The disc was rotated up to 6.5 minutes, within which nucleation and desired growth of the pellets were achieved. The product had distinct luster with optimized variables. If the lime particles were not assimilated properly, the product had residual bigger particles. The product was discharged carefully and spread for sun-drying. The pellets gained strength in about 8 hours of drying. Another disc of 150 kg/batch capacity was manufactured with same features. This was to hasten the production process. About 35t of pellets were produced and tried in Electric Arc Furnace (EAF). The trials were successful. There was no choking problem, and it also yielded several other benefits. Accordingly this invention relates to a process for producing micro-pellets of anthracite coal comprising the steps of grading coal, mixing and binding coal fines with lime and water, pelletizing said mixture in a disc pelletizer having an inclined disc angle and sun drying the resultant micro-pellets thereafter. Obvious alterations and modifications known to persons skilled in the art are within the scope and ambit of the appended claims. 4 1 3 JUL 2009 WE CLAIM 1. A process for producing micro-pellets of anthracite coal comprising the steps of screening coal, mixing and binding coal fines with lime and water, pelletizing said mixture in a disc pelletizer having an inclined disc angle and sun drying the resultant, micro-pellets thereafter. 2. The process as claimed in claim L wherein pelletization is carried out under a spray of water and the disc of the pelletizer is rotated at 11 rpm for about 6.5 minutes. 3. The process as claimed in claims 1 and 2, wherein 12% of lime and 15% of water on the basis of coal fines are mixed together prior to micro- pelletization. 4. Micro-pelletized anthracite coal made by a process as claimed in claims 1 to 3. 5. An electric arc furnace process for steel making wherein micro-pelletized anthracite coal as claimed in claim 4 is injected into said steel making process. 6. A process for producing micro-pellets of anthracite coal substantially as herein described. ESSAR STEEL LIMITED By their Agent and Attorney (KARUNA GOLERIA) of DePENNING & DePENNING

Documents:

1633-mum-2009-abstract.doc

1633-mum-2009-abstract.pdf

1633-MUM-2009-CLAIMS(AMENDED)-(23-5-2013).pdf

1633-mum-2009-claims.doc

1633-mum-2009-claims.pdf

1633-MUM-2009-CORRESPONDENCE(11-6-2013).pdf

1633-MUM-2009-CORRESPONDENCE(3-3-2010).pdf

1633-mum-2009-correspondence.pdf

1633-mum-2009-description(complete).doc

1633-mum-2009-description(complete).pdf

1633-MUM-2009-FORM 1(11-6-2013).pdf

1633-MUM-2009-FORM 1(23-5-2013).pdf

1633-mum-2009-form 1.pdf

1633-MUM-2009-FORM 18(3-3-2010).pdf

1633-mum-2009-form 2(title page).pdf

1633-mum-2009-form 2.doc

1633-mum-2009-form 2.pdf

1633-mum-2009-form 3.pdf

1633-mum-2009-form 5.pdf

1633-mum-2009-general power of attorney.pdf

1633-MUM-2009-REPLY TO EXAMINATION REPORT(23-5-2013).pdf