A Modified Godbert Apparatus for Determining Optimum Level of Beneficiation for Indian Non-Coking Coal for Power Generation

Abstract

The characteristics of coal depends on different parameters like rank, moisture, mineral matter content, macerals composition, etc. The combined effect of these characteristics governs the combustion behavior of coal in the furnace. The Indian ROM coals contain higher inherent mineral matter and a majority of these coals are used for power generation without any beneficiation; even though the environmental gazette notification of the Govt. of India requires all coal suppliers to install coal washeries. Combustion behavior of coal is evaluated by one of the following techniques: i.e., TGA, drop tube furnace, fuel efficiency test rigs, etc.; however, all these following techniques are costly and time consuming. The Godbert apparatus, which is low-cost simple equipment, can be used to evaluate the combustion behavior of coals. The minimum ignition temperature (the lowest temperature at which an ignition/explosion is observed as a flame) was determined for the ROM coal and density separated/various ash-content fractions up to 700°C. The results indicated that the coal containing up to 58% ash showed good flame/burning behavior. This study should provide guidance to coal washery operators to determine at what ash level the coal should be washed so that it can give better combustion rather than taking the ash value of 34% set up by the Indian Government.