Evaluation of Indian non-coking and semi-coking coals for metallurgical application

India has a huge reserve of coal belonging to Permian Period. 85% of these coals fall under non-coking category and are being used for power generation. Looking at the depletion of coking coals, there is a huge challenge for the Indian steel industry to manufacture coke using domestic coals. Utilizing Indian non-coking or inferior coals for coking purpose is a challenging task because of its higher ash content and poor rheological properties. These coals are less matured than coking coals and contain higher amount of organic and inorganic inerts. To study the effect of blending Indian thermal coals on coke CSR, eight different coals of varying characteristics have been used for experimentation. To improvise their coking ability and resulting coke strength on carbonization, phenol formaldehyde-based polymer addition has also been tried and tested. In most of the cases, it has been found that CSR got improved because polymer acts as a catalyst and improves the binding behavior and rheological property of the coal blend. Present work suggests that Indian thermal coals can be used up to 10% as one of the component coals in the blend for coke making with polymer addition.