Beneficiation of lignites by heat treatment

The proven Turkish coal reserves, particularly of lignites, amount to 10 billion tons. The majority of these lignites are characterized by their high ash (14% to 42%), moisture (15% to 55%) and volatile matter (16% to 38%) contents. In addition, the lignites contain sulfur levels ranging from 1% to 5%. As most of these coals are consumed without any upgrading processes; high moistures, low calorific values and high sulfur contents become the main causes of coal based air pollution. However, the advanced coal cleaning technologies can achieve substantial reductions in coal-based emissions. In this paper, low carbonization tests were carried out on lignite samples from Istanbul-Yeniköy region. The results indicate that these low-rank coals can be upgraded to the desired quality both in terms of calorific value and sulfur content.