Structural properties of carbonization products obtained from brown coals with different mineral matter contents

The structural properties of carbonization products obtained from different samples of initial and partially demineralized brown coals from the Borodino, Berezovo, and Kangalas deposits and the Yallourn deposit (Australia) were studied depending on the composition of the mineral matter of coal. Differences in the specific surface areas and the spatial structure characteristics of the organic matter of the test samples were found. It was shown that the carbonization products obtained from coals partially demineralized with the dilute solutions of acids, in comparison with the carbonization products of natural coals, were characterized by a lower concentration of an ordered graphite-like component (60–72% against 74–93%) but a higher degree of its graphitization (0.24–0.52 against 0.20–0.35). The dependence of these properties on the calcium content was revealed.