Depletion of high-grade resources has necessitated the use of low-grade fines, which contain good amount of mineral values and also liberate in finer sizes. Froth flotation, a physico-chemical surface-based process, is the most established solution, both technologically and economically, compared to other alternatives for fines beneficiation. For a successful and effective flotation performance, an understanding of the mineral surface and proper selection of the surfactant/reagent regimes along with their molecular chemistry and their specific adsorption mechanism are mandated. This chapter focuses on the complexity of the flotation process along with adsorption and interaction mechanism of different surfactants in accordance to mineral surface characteristics and their dependency on many microevents. To further strengthen mineral flotation chemistry and advancement of mineral engineering, research gears at investigating new surfactants, specific for particular mineral surface. The selection of reagents/surfactants with appropriate chemical composition and their administration are of critical importance in view of varied mineralogy, chemical complexity and size consist of feed material. Cost- effective and lower cost flotation reagents can be synthesized through insertion of new functional groups, molecular modelling of reagents for more environment-friendly nature, modifying the structure of other chelating agents and novel green chemicals from renewable resources, adding aliphatic alcohol and carboxylic acid to bio-based collectors and adding chaotropic anions to alkyl and aryl surfactants and organic and inorganic salts having strong orientation with more proton donor and acceptor; addition of another cationic group to known cationic surfactants can be tried for enhanced flotation performance. The study also provides an idea on the effect of other parameters like pH, composition of pulp, zeta potential, electrostatic potential, etc. For envisagement of a successful flotation performance, proper selection of the reagent system according to the specific surface and understanding of the mineral surface-specific adsorption mechanism are mandated.
Part of the book: Surfactants and Detergents
Mineral engineering is an interdisciplinary branch which includes many branches like physics, chemistry, math and sub branches like instrumentation, chemical engineering, mechanical engineering, geology etc. Amongst the various separation/beneficiation techniques of mineral processing, froth flotation is one of the most important fines beneficiation technique, which depends upon the surface and colloid chemical phenomena as the basis of selectivity. The method of separation relies on the surface state and colloidal chemistry of the ore particles and chemical reagents. Adsorption at the mineral solution interface is of major importance for the behaviour of mineral particles in the solution and for successful flotation performance. Adsorption of simple ions determine the change of the particle surface and electrochemical properties of the pulp/slurry phase and therefore affect the colloidal stability and the adsorption behaviour of reagent on the mineral surface. This chapter describes in detail about the role, importance and application of colloidal chemistry in mineral processing especially froth flotation. Froth flotation will remain a key unit operation for the treatment of low-grade ore fines for the decades to come with the overarching challenge as the need of the hour is to modify and improve existing process conditions so as to maintain an acceptable grade and recovery response for the feed whose liberation is more finer, more complex association of minerals and of lower grade.
Part of the book: Colloids