TABLE OF CONTENTS Physical processes, which usually do not require chemical agents are often sought after for materials separation. They are based on exploiting the differences in specific physical properties like specific gravity, magnetic properties, and electrical conductivity. Physico-chemical processes are based on the surface chemical characteristics of the components to be separated. Such processes, including froth flotation, ion flotation, precipitate flotation require the application of surface active agents, but the quantities required for a process are usually small, often in mg/L range. The success of the physical and physico-chemical methods is determined by variations in such properties between individual components to be separated and recovered. This will be discussed in this chapter, with examples of separation processes.
Separation of chemical species by physical separation has to be often preceded by material preparation to ensure desired separation by the technique used. In the physical techniques of processing the chemical composition of the components is unchanged; no chemical treatment occurs. The separation is based entirely on using the differences in physical properties between the chemical components. They include, as will be explained in the Chapter, specific gravity, magnetic properties, thermal and electrical conductivity and properties related to surface chemistry of the compounds. (Surface chemical treatment does not alter the bulk chemical composition of the compound thus treated).
A principal requirement for the success of any physical separation process is that the individual components to be separated should be satisfactorily liberated from each other; that is, the...
