Comparative Studies on the Settling Behavior of Indian Noncoking Coal Fines by Standard Jar Test and Instrument

The settling rate of coal fine particles by interaction with proper coagulants and flocculants is important in the water treatment/dewatering process. The standard test for measuring sedimentation rates is the jar test; the method is simple and direct. However, this method suffers from a number of disadvantages, despite its widespread application, it runs the risk of introducing large error due to the possible misinterpretation of the interface and the error may vary from person to person. To overcome this problem, different methods have been used for measuring the settling characteristics. In the present article, a German-made DCAT-11 instrument having bottom load weighing facilities synchronized with a computer to record the data and having facilities to measure up to 0.01 mg accuracy was used for testing a coal fines sample collected from an operating coal washery. The results show that the data obtained by the jar test are replicated by the data obtained from the instrument.