Literature review on the use of natural products in the flotation of iron oxide ores

The use of natural products is essential in the processing of iron oxide ores by flotation. It is the purpose of this review to trace the historic development of the use of some natural products in the processing of iron oxide ores. The reagents used for floating either iron oxides or activated silica are usually derived from vegetable origin, frequently from wood products containing primarily unsaturated carboxylic acids. In the reverse flotation of iron ores, the iron oxides are often depressed using polysaccharides, with various starches being extensively used. Hematite depression is usually conducted at high values of pH, and cationic surfactants are generally used to float off the silica. It is through the previous research and development of natural products that global commercial processing of iron oxide ores by flotation is economically viable, and the only method for treating fine grained iron ores. There are also some reports of the use of bacteria to modify the surfaces of the hematite leading either to its flotation or depression, but this has not been adopted at industrial scale as yet.