When evaluating the separation made by a coal cleaning device, particularly when examining new applications, it is important to have a procedure that is independent of the feed consist to the device and thus can show differences arising from various operating conditions. One such procedure is the generation of fractional recovery values, defined as the fraction of feed material in a given relative density interval for a given size interval which reports to the product, and the resulting curves. The methodology has been developed so that subjectivity on the part of the engineer is eliminated. This is achieved by first establishing a mass balance around the coal cleaning device, reconstituting the feed stream and then interpolating the feed and product streams into narrow size and narrow relative density intervals. Using these interpolated data, the fractional recovery values can be calculated and in turn fit to a mathematical function from which descriptive parameters, separation modulus, distribution modulus and material bypass parameters, can be obtained. Not only can the function parameters be estimated, but confidence limits can be placed on them. These parameters can be analyzed according to how they vary with operating conditions. An example comparing the results obtained from using this methodology to those obtained using a “standard” technique is presented in which published data for heavy media fine coal cleaning development is used.
All Science Journal Classification (ASJC) codes
- Fuel Technology
- Geotechnical Engineering and Engineering Geology