Abstract
Froth flotation process has shown superiority in processing of many low-grade ores including iron ores. However, there is need to continue developing cheap, more selective and environmentally friendly reagents. Due to the shortage of high-grade iron ores, many companies in South Africa and other countries are currently working on the beneficiation of low-grade ores and retreatment of tailings. In this paper, the performance of Macadamia oil as a frother on the flotation of low-grade iron ore was investigated. The critical flotation parameters such as frother and collector dosage, pH, particle size distribution and air flowrate addition on the reverse flotation of low-grade iron ore was studied. The results revealed that the ore assayed 50.35, 3.45 and 4.41% of Fe, Si and F respectively. The major phases were hematite, quarts and fluorspar. The results of the reverse flotation of low-grade iron ore from a fluorspar flotation tailing indicated that the reagent combination of 400 g/t Dodecylamine collector, 5 g/t Macadamia oil at a pH of 8.5, 35 % solids and 2.5 L/minute air flowrate with a particle size distribution of 80% passing 75 microns produced a concentrate assaying 61.60 % Fe and 2.48 % Si at a recovery of 65.21 % Fe. Flotation pH was the most sensitive parameter. Macadamia oil has huge potential in the flotation of low-grade iron ores.