A new approach for obtaining settling velocity in a thickener using statistical regression: A case study

In this research work, the parameters affecting the settling velocity within the thickeners were studied by introducing an equivalent shape factor. Several thickener feed samples of different densities including copper, lead and zinc, and coal were prepared. The settling tests were performed on the samples, and the corresponding settling curves were plotted. Using the linear regression analysis, the Cheinʹs equation was fitted to the experimental data in order to obtain the equivalent shape factors for the different minerals. Moreover, the relations between the equivalent shape factors and the settling parameters were investigated. The R-squared values for the fits proved the capability of the Chein’s equation to fit well on the experimental data (0.96?R2?0.99 for the copper sample, 0.96?R2?0.98 for the lead and zinc sample, and 0.93?R2?0.97 for the coal sample). The results obtained showed that the equivalent shape factor generally decreased with increase in the initial solid concentration. The equivalent shape factor for the coal sample in the samples with concentrations higher than 25% was negative but close to zero. This unusual behavior was explained by discussing the effects of the flocculants on the formation of the network structure in these samples. Determination of the equivalent shape factors would be an invaluable achievement in mineral processing. The researchers can simply put these factors into the Cheinʹs equation to calculate the settling velocity of the minerals instead of performing expensive and time-consuming experiments.