Strength evaluation of coke structure by hardness test

Abstract

Hardness of coke texture and elemental structure including coke matrix and pore was measured by micro Vickers test and Brinel test respectively. Vickers hardness of coke depends only on coke texture. Isotropic and Mosaic texture, which are derived from reactive of low rank coal, have largest hardness and Leaflet texture, which is derived from reactive of high rank coal, has lowest hardness. Average hardness of coke texture is therefore lower for the high rank coal. Brinel hardness was measured using an aluminum ball of 20 mm. The hardness was strongly influenced by porosity. Hardness of coke made from high rank coal tends to be lower than that made from low rank coal. Brinel hardness was well explained by porosity and coke texture hardness by micro Vickers test. Brinel hardness test was accompanied by the destruction of coke structure. The hardness was thought to stand for the resistance against destruction. Therefore strength of coke matrix is confirmed not to be weak even in case of coke made from low rank coal.