From Resource Recovery and Recycling from Metallurgical Wastes

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.

3.1 Material Preparation for Physical Separation

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).

3.1.1 Comminution

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...

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Screens consist of a surface with openings of specific sizes.  They may be made in many ways, including perforating a sheet, weaving metal wire or synthetic fibers or electroforming.  Among other uses, screens are commonly used to provide open but secure separation for a clean environment and flying objects, debris or insects. 
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Industrial process centrifuges are used to separate, extract, or wash products or materials in continuous, batch, industrial or environmental operations. As their name suggests, these centrifugal separators use centrifugal force to separate solid particles from a liquid solution.
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Topics of Interest

Recovery of metal values and other potentially useful products from metallurgical wastes often requires chemical treatment. While physical separation (Chapter 3) is still the most desirable route as...

Principles of Flotation Flotation is a physico-chemical separation process that utilises the difference in surface properties of the valuable minerals and the unwanted gangue minerals. The theory of...

Solid-liquid separation is concerned with mechanical processes for the separation of liquids and finely divided insoluble solids 11.1. PROCESSES AND EQUIPMENT Solid-liquid is not usually considered a...

Physical Methods of Wastewater Treatment Physical methods of wastewater treatment accomplish removal of substances by use of naturally occurring forces, such as gravity, electrical attraction, and...

10.1 INTRODUCTION Froth information is usually described as one of the most important aspects in flotation and also in other industrial fields. The investigation of frothing properties and its...