Mathematical Methods for Estimating Washability Curves

The main purpose of the project was to assess the feasibility of developing a fast and cheap procedure for estimating coal density distribution curves without using float-sink testing. The new envisaged procedure was most suited to plants with primary and secondary density separation, and required the use of density tracers.

In the project there are two primary objectives. The first objective is to assess whether an automatic procedure could be developed for using density tracers without the need for counting. The second objective is to assess whether knowing the separator partition curve for particles in 2 streams, and the density of particles in other relevant streams, would provide sufficient information to estimate the coal density distribution.

As the project was only a feasibility project, experimental work was not carried out. Instead already available data primarily from the Warkworth coal mine was used as test data.

Using procedures explained in the main report, both objectives were tested. The results are promising. It appears that it is possible to develop a more automated procedure for using density tracers, and the density distribution curve can be well-estimated without the need for float-sink testing.