Coal Concentrate Leaching for Reduction of Ash and Coke Reaction Index and Increasing Coke Strength after Reaction

Coal and coke ash play a significant role in the slag formation process within the blast furnace. As the ash content increases, so does the volume of slag, leading to a rise in energy consumption. A high proportion of ash contributes to an increase in the Coke Reaction Index (CRI), consequently reducing the Coke Strength after Reaction (CSR). CSR is a critical parameter determining the coal quality and influencing the blast furnace’s efficiency. The enhancement of CSR relies on reducing the alkalinity of coal ash. To achieve this, dilute acid leaching experiments were conducted using Design Expert software and the response surface method. The optimal outcome revealed a reduction in ash percentage from 7.73 to 4.56% and an increase in CSR index from 35.05 to 59.93%.