Improved dewatering of iron ore fines by the use of surfactants

• Published in: Powder technology 2016-01, Vol.287, p.43-50
• Main Authors: Patra, A.S., Makhija, D., Mukherjee, A.K., Tiwari, R., Sahoo, C.R., Mohanty, B.D.
• Format: Article
• Language: English
• Subjects: Dewatering; Iron ore; Moisture; Surfactant; Zeta potential
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2015.09.030

The role of chemical reagents to reduce moisture in iron ore fines is explored in the present work which includes ionic and non-ionic surfactants. The washing of iron ore in mineral processing plants result in moisture of about 11–14% in the fines and about 4% in the sized ore. The moisture level goes up to 16% in the fines during the monsoon season. Dewatering of fines is a major problem in all mineral processing industries. As the ores deteriorate in their quality, generation of fines and ultra-fines is increased proportionally. The ultra-fines adsorb much moisture due to their extremely large surface area and these tend to adhere to the relatively coarser fines, thus increasing the percentage of moisture in the fines. This paper reports an experimental investigation on the effect of anionic, cationic and non-ionic surfactant on the dewatering behaviour of iron ore fines (−6mm) and also plant trials with the selected surfactant. The surfactants taken up for studies are sodium dodecyl sulphate (SDS), poly ethylene oxide 4000 (PEG), cetyl trimethyl ammonium bromide (CTAB). All the surfactants were found to give good results w.r.t. moisture reduction. From the laboratory experiments it was observed that there was reduction in gangue (mainly aluminosilicates) level as well by the application of the surfactant. The promising results of the laboratory scale tests led to plant trials with SDS which gave 2 to 4% (absolute) moisture reduction in the fines. [Display omitted] •High moisture content of iron ore fines leads to operational problems.•Dewatering equipment and screens have limitations for fine particle dewatering.•Dewatering aids are thus essential for effective dewatering.•Different surfactants taken and their role as dewatering aid explored•Plant trials conducted with the most effective surfactant