Evaluation of Flotation Collectors in Developing Zero Waste Technology for Processing Iron Ore Tailings

Abstract

Reverse cationic column flotation technology is gaining traction in iron ore processing industry for recovering iron values from iron ore slimes/tailings. Development and selection of appropriate collector suitable to the material to be processed plays vital role in the development of the process/technology. Three cationic collectors which are vegetable oil based, biodegradable and environmental friendly were tested for their efficacy in reducing alumina and silica and improve iron content in the tailings of an operating iron ore washing plant. Selectivity index as defined by Douglas was used as response parameter to measure the efficiency of separation while comparing the performance of these collectors during flotation tests. Sokem 522C proved to be better in comparison to Sokem 701 and Sokem 702 with the highest selectivity index of 20.87. The concentrate generated analyzed 63.30% Fe, 2.20% SiO2 and 2.52% Al2O3 with 69.00% weight recovery and 79.21% Fe recovery from the tailings containing 55.14% Fe, 17.34% SiO2 and 4.04% Al2O3. The concentrate generated is suitable for pellet making due to its attractive granulometry and acceptable levels of alumina content (≤ 2.50%) in it. The tailings generated in this process could be utilised for cement manufacturing and tiles or pavement blocks making.The process developed is ‘zero waste’ while mitigating the environmental issues related to managing tailings in iron ore processing plants.