Development of anisotropic texture in co-carbonization of low rank coal with pitch-evaluation from hydrogen donor and acceptor abilities of coal and pitch

Abstract

The extent of development of anisotropic texture in cokes prepared from various coals or blended coals in co-carbonization systems was assessed by using the ratio of hydrogen donor ability to acceptor ability. A parameter D/ A, corresponding to the amount of hydrogen transfer during carbonization in the system of blended coal and pitch additive has been proposed to give a measure of the aforesaid development of anisotropic texture in resultant cokes. In pitch A/non-caking coal systems, blending the pitch A with coal to a value of D/ A − 0.22, D/ A − 0.28 and D/ A − 0.40 gives mainly fine-granted mosaics, medium-grained mosaics and coarse-grained mosaics, respectively. The Gieseler plastometry and high-temperature 1H-NMR were also used to obtain informations about the mobility of the co-carbonization system. A good relation was found between D/ A, and the solidification temperature determined by the Gieseler plastometry. Such an approach based on the concept of D/ A parameter provides a guideline for selecting pitch as a modifier for low rank coal carbonization.