Coke strength estimation considering the micro- and macrosructure

Recent research topics on metallurgical coke strength are summarized in this paper. In order to minimize a energy consumption in a blast furnace ironmaking process, usage of higher strength coke is necessary. In a conventional approaches, drum and tumbler test are used as indices of coke strength and there are few approaches from mechanics of materials. Recently authors start trying to study the coke strength by new methods which are developed in research area on mechanics of materials. Micro-structural analysis of coke using the overlaying mesh finite element method can provide a fracture information of complex micro-structural geometry such as coke. Nano-indentation method gives us the coke matrix elastic modules experimentally. Homogenization method enables us to know a microscale stress distribution on coke matrix by macroscopic deformation. These experimental and numerical approaches will show us a coke mechanical behavior in the blast furnace. Further research should be required to understand coke fracture mechanisms such as adhesive strength among non- or slightly coking coals or between coal particle and inert texture. Reaction mechanisms of coke lump in the blast furnace should also be understood because coke degradation by chemical reactions influences coke microstructure which is strongly related with the coke fracture.