The quality of incoming coal from the mines is ascertained by the analysis of Total Moisture, ash, proximate analysis, gross calorific value (GCV), fluidity, dilation, Crucible Swelling Number (CSN), and Sulphur. These tests are currently conducted offline in dedicated laboratories with appropriate instruments after sample extraction, sample preparation, and pulverization. This manual testing process takes approx. 4 hours to obtain the coal analysis results, which significantly delays the execution of any correction in the coal beneficiation process as well as in boiler operation.
Currently, there is no online system in place for monitoring the quality of coal coming from the mines or being fed to the boilers, which results in many operational challenges. Prompt gamma-ray neutron activation analysis (PGNAA) has been tried, which provides only ash content. However, this device is very expensive, and the results are not reliable due to its dependency on several operational parameters.
Thus, an online system for coal analysis is required which can provide a quick analysis (within 10 minutes) of the coal quality (as per the parameters listed above) with an allowable tolerance of ±0.1% with respect to the laboratory results.