Injection of petroleum coke-oil slurry into blast furnace.

Abstract

For the utilization of petroleum coke-oil slurry as a substitute fuel for blast furnaces, the development of an injection technique of petroleum coke-oil slurry into a blast furnace was taken place. The petroleum cokes used in this study were delayed coke (DC) and fluid coke (FC).Laboratory tests and a pilot plant test were carried out for a study of rheological properties of slurries. It became clear that DC slurry has much higher viscosity than heavy oil and FC slurry has higher settling velocity than DC. Based on these results, a slurry injection system was designed and a demonstration plant test was performed at Kobe No. 1 BF with 4 tuyeres injection for over 4 months. The sampling of gas and dust was performed to evaluate the combustibility of slurry in the raceway.It was confirmed that it was possible to inject 50% slurry without additives as easily as heavy oil for a long period and the new injection system using a circulating loop provided a circumferentially uniform distribution of injected slurry. The combustibility of the substitute fuel decreased in the order of heavy oil, DC slurry and FC slurry. Moreover, the replacement ratio of slurry to coke was estimated to be about 1.0.Consequently, it is concluded that petroleum coke-oil slurry can be used as a substitute fuel for blast furnaces.