COKING COAL : These coals, when heated in the absence of air, form coherent beads, free from volatiles, with strong and porous mass, called coke.
SEMI COKING COAL : These coals, when heated in the absence of air, form coherent beads not strong enough to be directly fed into the blast furnace. Such coals are blended with coking coal in adequate proportion to make coke.
NLW COKING COAL : These coals are having inferior coking properties to the medium coking coal but produce weak coke. They are, however, useful for production of metallurgical coke in blends with matching metallurgical coals.
NON-COKING COAL : These are coals without coking properties.
HARD COAL : Hard coke is formed from coking / semi-coking coal through the process of carbonisation.
WASHED AND BENEFICIATED COAL : These coals have undergone the process of coal washing or coal beneficiation, resulting in value addition of coal due to reduction in ash percentage.
MIDDLINGS : Middlings are by-products of the three stage coal washing / beneficiation process, as a fraction of feed raw coal.
REJECTS : Rejects are the products of coal beneficiation process after separation of cleans and / or middlings, as a fraction of feed raw coal.
CIL COKE / LTC COKE : CIL Coke / LTC Coke is a smokeless, environment friendly product of the Dankuni Coal Complex, obtained through low temperature carbonisation.
COAL FINES / COKE FINES : These are the screened fractions of feed raw coal and LTC coke / CIL Coke respectively, obtained from the Dankuni Coal Complex and other coke oven plants.
TAR / HEAVY OIL / LIGHT OIL / SOFT PITCH : These are products from Dankuni Coal Complex using low temperature carbonisation of non-coking coal in vertical retorts.
|A. COKING COAL|
|Steel I||Ash not exceeding 15%|
|Steel II||Ash exceeding 15% but not exceeding 18 %|
|Washery I||Ash exceeding 18% but not exceeding 21 %|
|Washery II||Ash exceeding 21% but not exceeding 24 %|
|Washery III||Ash exceeding 24% but not exceeding 28 %|
|Washery IV||Ash exceeding 28% but not exceeding 35 %|
|B. SEMI COKING COAL|
|Semi Coking I||Ash + moisture not exceeding 19 %|
|Semi Coking II||Ash + moisture exceeding 19 % but not exceeding 24 %|
|C. NON-COKING COAL|
|Grade||Gross Calorific Value bands for Non-Coking Coals
(In Kilo Calories/Kilogram)
|G2||6701 to 7000|
|G3||6401 to 6700|
|G4||6101 to 6400|
|G5||5801 to 6100|
|G6||5501 to 5800|
|G7||5201 to 5500|
|G8||4901 to 5200|
|G9||4601 to 4900|
|G10||4301 to 4600|
|G11||4001 to 4300|
|G12||3701 to 4000|
|G13||3401 to 3700|
|G14||3101 to 3400|
|G15||2801 to 3100|
|G16||2501 to 2800|
|G17||2201 to 2500|
|D. HARD COKE|
|By Product Premium||Not exceeding 25 %|
|By Product Ordinary||Exceeding 25 % but not exceeding 30 %|
|Beehive Premium||Not exceeding 27 %|
|Beehive Superior||Exceeding 27 % but not exceeding 31 %|
|Beehive Ordinary||Exceeding 31 % but not exceeding 36 %|
|SUITABILITY OF COAL|
|E. HARD COKE|
|Industry||Type of Coal Required|
|Steel making||Coking and semi-coking coal, direct feed and washed; blendable coal; low ash % Assam and Ranigunj coal|
|Steel making, sponge iron industry||Non-coking coal of high Initial Deformation Temperature (IDT) (>1200 degrees Celcius)|
|Cokeries / coke oven plants||Coking and semi-coking coal|
|Briquette making / domestic fuel making||Semi-coking and non-coking coal; middling & rejects of washeries|
|Special Smokeless Fuel (SSF)||Semi-coking coal of Coking Index 8 10|
|Power sector||Non-coking coal; middlings of coking coal washeries; washed coal of non-coking coal washeries|
|Cement sector||Non-coking coal; middlings of coking coal washeries|
|Glass and potteries||Long Flame non-coking coal|
|Cast iron castings||Hard coke|
|Steel castings||Non-coking coal|
|Bricks||Non-coking coal; middlings of coking coal washeries|
|Old boilers||Superior grades of non-coking coal|
|Halwais, domestic use, hotels, etc.||Non-coking coal; CIL Coke / LTC Coke ///|