Note:
Although limits of size cannot be exactly defined, coke grains obtained by grinding belong to coarse particulate carbon for grain sizes above ca. $100\text{μ}\text{m}$, or to fine particulate carbon for grain sizes below ca. $100\text{μ}\text{m}$. Colloidal graphite obtained by grinding of natural graphite is a typical extra fine particulate carbon. Industrial carbon materials (such as electrodes) are made with fillers composed of coarse particulate carbon (coke grains) and fine particulate carbon (flour), and sometimes even colloidal carbon, carbon blacks or soot). They are therefore polygranular materials.