Influence of inclined channel spacing on dense mineral partition in a REFLUX™ Classifier. Part 1: continuous steady state

The REFLUX™ Classifier, which consists of a lower fluidized bed system and upper system of parallel inclined channels, was fed continuously to beneficiate a dense mineral ore covering a nominal particle size range up to 300 μm. The purpose of the work was to (i) establish the partition surface of the REFLUX™ Classifier for dense minerals over the above size range, and (ii) quantify the improvement in the separation performance of the REFLUX™ Classifier for different inclined channel spaces of 6 mm and 3 mm. The narrower 3 mm channels consistently achieved higher grades and recoveries than the 6 mm channels. Standard sink-float analysis produced a composite D50 of 3902 kg/m³ and Ep of 426 kg/m³ for the broad size range of 38-300 μm. The interpolation and mass-balancing algorithm (Galvin et al., 2018), which links the feed, product, and reject density distributions to the partition function, was applied to fractionation data derived from the sink-float method, generating a composite D50 of 3949 kg/m³ and Ep of 442 kg/m³, in excellent agreement with the standard method. Analysis of the narrow size fractions showed the D50 decreased with increasing particle size to the power -0.22, while the Ep was reasonably constant at about 325 kg/m³ for each of the narrow size fractions.