Introduction

Adsorption of surfactants on minerals is the basic process governing flotation. It is controlled by various physicochemical processes in the pulp involving interactions among the mineral particles, surfactants, dissolved inorganics, solvent species and other additives such as polymers. Adsorption can be considered as selective partitioning of the surfactant adsorbate into the interfacial region, resulting from the more energetically favourable interactions between the adsorbate and the solid than those between the former and the species in the bulk solution. The interactions leading to adsorption include chemical bonding, electrostatic interaction, desolvation of the surfactant polar group and the mineral surface species, hydrogen bonding, van der Waals interactions, etc.

Water chemistry plays an important role in the adsorption process by affecting the surfactant-solution equilibria, the mineral-solution equilibria

Young FR (1989) Cavitation. London: McGraw-Hill.

Zhou ZA, Xu Z and Finch JA (1994) On the role of cavitation in particle collection during flotation - a critical review. Minerals Engineering 7 (9): 10731084.

Zhou ZA, Xu Z and Finch JA (1995) The minimum recovery zone height in flotation columns from particle-bubble collision analysis. Transactions of the Institution of Mining and Metallurgy 104: C102-C106.

Zhou ZA, Xu Z and Finch JA (1995) Fundamental study of cavitation in flotation. In XIX International Mineral Processing Congress, vol. 3, pp. 93-97. San Francisco, USA: SME.

Zhou ZA, Xu Z and Finch JA (1996) Effect of gas nuclei on hydrophobic coagulation. Journal of Colloid Interface Science 179: 311-314.

Zhou ZA, Xu Z, Finch JA and Liu Q (1966) Effect of gas nuclei on the filtration of fine particles with different surface properties. Colloids & Surfaces 113: 67-77.

Zhou ZA, Hu H, Xu Z et al. (1997) Role of hydrodynamic cavitation in fine particle flotation. International Journal of Mineral Processing 51: 139-149.

Zhou ZA, Langlois R, Xu Z etal. (1997) In-plant testing of a hydrodynamic reactor in flotation. In: Finch JA, Rao SR and Holubec I (eds) Processing of Complex Ores, pp. 185-193. Sudbury, Canada: CIM.

and subsequently the interactions between the surfactants and the mineral particles. The interactions in mineral-solution system include dissociation, micell-ization and precipitation of the surfactant, dissolution of a small amount of solids followed by hydrolysis, complexation and precipitation of the dissolved species, and the interactions between dissolved mineral species with surfactant in the bulk in various forms. The dissolved species, including those introduced due to dissolution from all the minerals present in the ore and those from the water source, fresh and recycled, are the major elements that affect the water chemistry. While impurities introduced from water can be controlled to some extent, the chemical species released into the system due to dissolution from the minerals cannot be avoided. In systems containing soluble or sparingly soluble minerals where the extent of dissolution is markedly higher than that in most oxide/silicate systems, the effect of dissolved mineral species can be drastic. Understanding the mineral-solution-surfactant chemical equilibrium under different physicochemical conditions is critical for developing reagent and processing schemes for separation.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

Get My Free Ebook


Post a comment