Thermal behaviour and reactivity of green petroleum cokes used as additives in metallurgical cokemaking

Abstract

One calcined and five green petroleum cokes were subjected, in a thermobalance, to controlled thermal treatment up to 1000°C in an N 2 atmosphere and then reacted with CO 2 at this temperature. Based on the DTG curves, the volatile matter released during the pyrolysis stage was divided into five intervals (<150, 150–400, 400–500, 500–750 and 750–1000°C). Relevant information can be obtained from the amount of volatile matter released in these intervals. In particular, it was found that the amount of volatile matter released in the 400–500°C interval can be related to the modifications observed in the fluidity of coal/PC blends which in turn affects the properties of metallurgical cokes obtained from these blends. Petroleum coke reactivity parameters were also obtained. A good correlation was found between the reactivity at 20% of conversion ( R 20) and the optical texture index (OTI) calculated from the quantitative analysis of anisotropic components in the cokes. In contrast with the relevance of the information obtained from the volatile matter released during the thermal treatment of the petroleum cokes, the reactivity of petroleum cokes was found to have little influence on the reactivity of metallurgical cokes prepared from coal/PC blends.