Characterisation and surface chemical studies on ultrafine iron ore

Abstract

During the wet processing of iron ores, a substantial amount of slimes are generated. The slime contains very fine iron bearing mineral particles which are difficult to remove and cause environmental pollution when discharged. In this paper, an attempt was made to study the settling and dispersion behaviour of the very fine iron ore mineral particles which is treated as waste in the presence of different reagents. The waste material contains of 52.56% Fe which is significant from iron content view point. Characterisation studies such as size analysis, mineralogical and XRD of the overflow sample of hydrocyclone was carried out and discussed. The sample was very fine in nature (90% below 17.32 µm) and the major minerals were seen as hematite and goethite while the major impurity was found to be quartz as confirmed by the mineralogical investigation. Surface chemical studies show that the isoelectric point (iep) was at pH 6.75. Tannic acid, starch show a good dispersant property with higher turbidity value upto a time period of 20 minutes, whereas CMC show a faster settling of the sample for the same time period with low turbidity value. Tannic acid shows low settling behaviour corroborating the supernatant turbidity value. There is good correlation between zeta potential and the supernatant turbidity value. Starch with 50 ppm gives a good recovery of 79.82% by weight with a Fe content 55.52%.