Study of froth behaviour in a controlled plant environment – Part 2: Effect of collector and frother concentration
Introduction
An investigation into froth zone recovery using a unique device is presented. The device has ability to collect the froth dropback particles and allow independent measurement of both froth and pulp phase recoveries. The effect of operating conditions (froth depth and air flow rate) on the froth performance was recently reported by the authors (Rahman et al., 2015). The work was carried out at the Northparkes concentrator (NSW, Australia) using a feed taken directly from the head of the cleaner scavenger bank.
This paper presents the results of a parallel investigation into the effect of the chemical parameters on the froth behaviour where the influence of collector and frother concentration on froth recovery was studied.
Section snippets
Experiments
The design of the froth dropback (FDB) device, a schematic diagram of the rig and the experimental procedure are given in Rahman et al. (2015). Feed to the cell was taken from the head of the cleaner–scavenger of Module 1 of Northparkes copper concentrator. The procedure followed for the treatment of raw data may also be found in the previous paper.
In Module 1 reagents were added at different stages of the flotation circuit. The cleaner–scavenger feed contained approximately PAX – 5 g/ton and
Effect of collector concentration: overall recovery
Two consecutive runs, donated as Runs 5 and 6, were completed at four different collector concentrations of 5 g/ton, 10 g/ton, 15 g/ton and 22 g/ton. The superficial air velocity (Jg) and froth depth were maintained at 1 cm/s and 240 mm, respectively. Collector (PAX) was added to the feed sump.
The average froth recovery Rf, collection zone recovery Rc and overall recovery R, at different collector concentrations are presented in Table 1. The table shows that the collector concentration has a distinct
Comparison with previous froth recovery results
The results from our previous work (Rahman et al., 2015) which forms the first part of the study and the present study show that froth recoveries can be very high, and it is of interest to compare the results obtained here with those found previously. The results can be summarised as follows, for each of the key variables.
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Air flow rate: The froth recovery varied from 71% to 91%.
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Particle size: The froth recovery is lowest for coarse 150 μm particles (35%) at low air rates, and highest for fine 10
Conclusions
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The collector concentration had a significant effect on the flotation of the Northparkes ore. Increasing the collector concentration significantly improved the capture of particles in the collection zone. However, at higher collector concentrations, the froth recovery decreased, presumably because of froth instability. A decrease in the grades of concentrate and dropback was found with increasing collector concentration, suggesting that higher collector additions are more likely to improve the
Acknowledgments
Financial support from the sponsors of the AMIRA (Australian Mineral Industry Research Association) Project P90 is greatly acknowledged. The authors wish to thank Kitty Tang, Cagri Emer and Ghislain Bournival for their contribution to the test work. The authors would also like to acknowledge the support from the Northparkes concentrator personnel during the testwork, especially Jaclyn McMaster, Tom Rivett and Heather Gault.
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Cited by (12)
Coarse particle flotation: A review
2024, Minerals EngineeringEffect of reagent interaction on froth stability of coal flotation
2022, FuelCitation Excerpt :Research on the role of non-frothing reagents on bubble size and bubble stability [16] strongly suggested that the role of PAX and the synergistic effect of PAX, NaHS and MIBC in modifying the air–liquid interface should be considered when using these reagent combinations. Rahman [17] has conducted similar research and suggested that despite the above studies being carried out in two-phase (air and water), it is nevertheless important in the flotation process to add particles. The hydrophobic particles in the systems could: firstly, change the surface stresses at the gas/liquid interface, and hydrophilic particles; and secondly, modify the rheology of the interstitial fluid (the Plateau borders) within the froth [18].
Flotation of coarse coal particles in a fluidized bed: The effect of clusters
2020, Minerals EngineeringCitation Excerpt :Thus some particles that have risen into the froth phase are thought to have become disengaged from the bubbles and have dropped back into the liquid. Drop back has been an elusive quantity to measure, and there have been a number of attempts (Falutsu and Dobby, 1989; Seaman et al., 2004; Ata and Jameson, 2013; Rahman, Ata and Jameson, 2012, 2013, 2015a, 2015b). The prevalence of bubble-particle clusters in the region beneath the froth may lead to a new interpretation of the phenomenon of ‘froth dropback’.
Effect of gas superficial velocity (Jg) and frother/collector (MIBC/X-343) reagent dosage on froth horizontal displacement and galena drainage
2017, Minerals EngineeringCitation Excerpt :This is in accordance with Rahman et al. (2015a), who reported a positive effect on the overall recovery as well as the recovery of froth and water. Rahman et al. (2015b) use higher values of Jg, but the same positive effect was observed. On the other hand, lower Jg and MIBC/X-343 promote both coalescence and bubble collapse.
On the detachment of hydrophobic particles from the froth phase
2016, Minerals EngineeringCitation Excerpt :It was also found that as the fraction of fine particles in the feed increases, the froth recovery of coarse particles increases proportionally, presumably due to the froth stabilizing effect imposed by the fine particles. High froth recovery values were also obtained in the plant size flotation cell (Rahman et al., 2015a,b). The froth recovery values reported in the literature vary significantly not only because of different ore systems used but also due to the different techniques employed in the calculation and estimation of Rf.