In this paper, a review of our works performed in Institute of Coal Chemistry Polish Academy of Sciences has been made. The recent ultrasonic investigations of natural (coal) and processed carbon materials: compressed expanded graphites, cokes and composites of epoxy resins with coal particles have been described. Many pieces of information about coal structure, considered as a system of two phases: macromolecular and molecular, were obtained using various independent ultrasonic methods. It was confirmed the polymeric character of coal structure. It was found that the ultrasonic velocity and density of coal can be used for an estimation of cross-linking degree of coal (averaged structural unit of macromolecular phase). The correlation between the absolute temperature coefficient of ultrasonic velocity and the mean molecular mass of coal extracts (molecular phase) was stated. Four new ultrasonic methods of study of coal structure were proposed.

 

Monolithic, high porous samples of compressed expanded graphites, suitable for adsorbent supports were studied. It was found that the ultrasonic measurements can provide an information not only on bulk porosity but also on pore shape and pore packing geometry. Contrary to usually used methods (mercury porosimetry, BET, etc.), these measurements take into account not only open but also closed pores. Impregnated and then heat-treated monolithic samples of compressed expanded graphites were also investigated.

 

Some physical properties of cokes produced in a coking plant (large scale) and the laboratory apparatus (small scale) were studied and compared with usually used technical parameters, i.e., M₄₀, CSR and CRI to elaborate new method of qualification of cokes. Studies are in progress.