The aim of this study was to investigate the possibility of producing sinter/pellet grade concentrate from iron ore tails. Two different wet flow sheets were considered. The first consists of a teetered bed separator (TBS) followed by a gravity concentration resulting in a product quality with 65.54% Fe, 4.96% SiO₂ and 1.50% Al₂O₃ content ensuring 68.52% iron recovery. In the second option, the iron ore tail is treated in a similar approach, but the gravity concentration replaced by magnetic separation results in a product quality with 65.34% Fe, 3.70% SiO₂ and 1.00% Al₂O₃ with 70.91% of iron recovery.

In the present investigation, the effect of the most important process variables, which are teeter water velocity (TW) and pressure set point (SP), on the classification and beneficiation performance of a laboratory-scale teetered bed separator (TBS) was evaluated and discussed. Pure silica sand, magnetite concentrate and their artificial mixture were used to observe the effect of mineral density. Classification test results revealed that separation cut size linearly increases with increasing TW and SP. From the beneficiation studies and the size-by-size chemical analysis of artificial mixture, it can be concluded that significant removal of silica is possible by employing TBS.

In the present work, a conventional hydrocyclone and newly designed laboratory scale crossflow separator (CS) were evaluated and compared experimentally. Hydrocyclone and CS was compared at the very similar actual cut size values. In this condition, a finer overflow product was obtained by using CS. Imperfection value of CS was 0.22 and lower than the operating hydrocyclone. The imperfection coefficient for the classifier ranged between 0.2 and 0.5. CS was illustrated good classification efficiency as a classifier. The CS can be used as an alternative and more efficient classifier to further improve the classification efficiency of close circuit grinding operations.

The classification performance of a laboratory-scale teetered bed separator (TBS) was investigated through Whiten’s efficiency curve approach. Higher levels of teeter water rate (TW) and pressure set point (SP) enhance the sharpness parameter (α) but reduce the fish-hook parameter (β). The sharpness parameter (α) was found to be dependent on TW and SP. Apart from the process variables, density of the mineral has significant effect on the model parameters. It is established that the Whiten’s efficiency curve approach has a potential to predicting classification performance of TBS by using experimental results with considerable degree of accuracy.

A set of experiments was performed using single replication and a statistical design by using a pilot scale REFLUXTM Classifier (RC300) on three different streams of an operating plant. In the present work, fluidization water rate and pressure set point were considered. Other factors, including feed rate and feed solid content, were maintained constant and were not examined. Based on the mass balanced sampling and pilot scale test results RC can give a similar performance in rejecting gangue from chromite ore compared to the existing spiral circuit. In addition to this, different concentrates can be obtained with a wide recovery/grade range by adjusting the main operational parameters. RC can produce a pre concentrate which is a grade of 18.35 Cr2O3 with a 43.40% mass recovery and 87.50% chromite recovery which is very close to the performance of existing circuit. The chromite grades of sample C clearly show that the final concentrate can be upgraded by using a finishing RC. The chromite recovery comparison between the fine table and RC 300 (high grade) clearly shows that the separation mechanism and the existence of parallel inclined plates positively affect the fine particle recovery. According to the results, a new flowsheet can be designed by using the spirals and the RC. This would eliminate the need for both shaking tables and dragon tables and the required footprint. The test results revealed that RC could be suitable device as a pre-concentration and final concentration operations in chromite beneficiation plants.