Study On Effect Of Ash Component On Coke Thermal Performance

Coke thermal performance includes coke reactivity (CRI) and coke strength after reaction (CSR). It depends not only on coal performance for coking but also on coal ash composition. The alkaline oxides in the ash are positive catalyst for coke carbon-solution reaction, they can increase coke reactivity and decrease coke strength after reaction; and the acidic oxides in the ash are negative catalyst of coke carbon-solution reaction, they can reduce coke reactivity and enhance coke strength after reaction. The balance of the both represents the ash catalytic ability. It is often shown as mineral catalytic index MCI. In the paper, firstly, coal properties for coking in WISCO, ash composition and mineral catalytic index are researched and coking experimentation in laboratory coke-oven and CRI and CSR determination are carried out; then the ash composition and mineral catalytic index of coke from commercial coke-oven are studied, and the CRI and CSR of the coke are measured. Lastly, the correlation between G, Vdaf and MCI is analyzed. The experimental results show that, the ash alkali content (K2O+Na2O) of coals for coking is high, the ash alkali content of Xinwen, Tianzhuang, Hancheng and Huanglin is all more than 1%, the rest near 1%; the influence of ash MCI on CRI and CSR is obvious, CRI and MCI is positive correlative and CSR and MCI is negative correlative. MCI can show as both coal ash components and coke ash components, the both are almost the same. The mathematical models from multi-regression reveal the essence that all factors affect CRI and CSR. They can be used to predict CRI and CSR and to direct and optimize the coal blending and improve coke quality.