Sub 38 µm Wet Sizing with Sieves

Abstract

The development of methods to accurately wet-sieve at sub 38 micron size fractions have allowed important information to be gathered on a range of materials in the coal and minerals processing industries. Methods have been developed to sieve at 2, 5, 10 and 20 micron. Using sub 38 μm sieves gives the ability to actually study (on a bulk scale) the material within these size fractions. For example, the actual material in the 0 to 10 µm or 10 to 20 µm size range can be studied. As well as producing the particle size distribution, sufficient quantities of each size range can be collected to allow further test work and laboratory analysis to be performed. Other techniques do not allow for this. Laser sizing gives only a size distribution. Cyclosizers operate on a very small sample size (20 g total) and have numerous other problems that are discussed in this paper. A range of data from samples that have been gathered and processed at the sub 38 µm sieve sizes is presented as well as direct comparisons of the various sizing techniques. Materials so far studied are: magnetite, coal flotation feed, product and reject, coal thickener underflow and mineral sulfides.