Improving Coke Strength Using Solvent Extracted Coal
(Room 209B)
09 May 17
4:30 PM
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5:00 PM
Tracks:
Alternate Cokemaking: Coal Compaction, Briquetting & Reverts
Coal is one of the important raw materials for steel industry. Indian coals contain high ash-yield. It is difficult to remove ash-yield from the coal by physical beneficiation. Coke acts as a fuel, reducing agent and support the burden in blast furnace. Therefore, coke should have sufficient strength along with suitable chemical and physical properties. A process of solvent extraction of high ash-yield coal was developed and demonstrated at 40 kg/batch bench scale plant. The clean coal yield was in the range of 30-40% with less than 10% ash. Free swelling index (FSI) was improved by 4 to 5 units. The extracted coal was used in coke making, replacing prime coking coal (5, 10, and 15%) from the blend. When 50% prime coking coal and 50% weakly coking coal was used, coke strength after reaction (CSR) value was 40.3%. The CSR value was increased to 49.7% and 53.9% when prime coking coal was replaced with 5% and 10% solvent extracted coal. This improved CSR is corresponding to more than 65% CSR in the plant. The CSR value further decreased to 51.5% when prime coking coal was replaced with 15% solvent extracted coal. Our study shows that 10% prime coking coal can be replaced in the blend with solvent extracted coal.