Collector/water/mineral system

Electrochemical phase diagrams have been used to investigate the collector water mineral system in which the experimental potential for flotation is compared with thermodynamic equilibriums for reactions in mineral/oxygen/collector system to... 

Abstract In the beginning, the mixed potential model, which is generally used to explain the adsorption of collectors on the sulphide minerals, is illustrated. And the collector flotation of several kinds of minerals such as copper sulphide minerals, lead sulphide minerals, zinc sulphide minerals and iron sulphide minerals is discussed in the aspect of pulp potential and the nature of hydrophobic entity is concluded from the dependence of flotation on pulp potential. In the following section, the electrochemical phase diagrams for butyl xanthate/water system and chalcocite/oxygen/xanthate system are all demonstrated from which some useful information about the hydrophobic species are obtained. And some instrumental methods including UV analysis, FTIR analysis and XPS analysis can also be used to investigated sulphide mineral-thio-collector sytem. And some examples about that are listed in the last part of this chapter. 

Dixit and Biswas124 dealt with the relationship between H+ an OH- concentrations and adsorption of an anionic collector on a mineral surface and its flotability. They used the system zircon-Na oleate. If Na oleate is dissolved in water the following equilibrium sets up ... 

Most of the theories on interactions of surfactants with minerals are closely related to their solution chemistry. For example, the ion-exchange adsorption theory proposed by Gaudin (1932, 1934) and Wark (1938) and the molecular adsorption theory proposed by Cook and Nixon (1950) are based on the dissociation equilibria and states of the collectors in water. More recently, Somasundaran (1976) observed that ion-molecule complexes of long-chain surfactants in flotation systems can have high surface activity depending upon the association equilibria of the surfactants in solutions (Ananthapadmanabhan et al., 1979 Kulkarni and Somasundaran, 1980). Also the cationic flotation behavior of salt type minerals is closely related to the formation of alkyl amine salt (Hu and Wang, 1990). In this chapter, solution equilibria of reagents relevant to selected flotation systems are examined. 

In many flotation systems, the electrical nature of the mineral/water interface controls the adsorption of collectors. The flotation behavior of insoluble oxide minerals, for example, is best understood in terms of electrical double-layer phenomena. A very useful tool for the study of these phenomena in mineral/water systems is the measurement of electrokinetic potential, which results from the interrelation between mechanical fluid dynamic forces and interfacial potentials. Two methods most commonly used in flotation chemistry research for evaluation of the electrokinetic potential are electrophoresis and streaming potential. 

Then, water is pumped to a pool through a special well system. The main amount of water is pumped to the pool from collector and placed before the waterproof layer. At high concentrations of mineral salts in the water, it is diluted with water, pumped from a deep well, and placed under the waterproof layer. Next, water is enriched with oxygen in a special cascade-type aerator, then filtered, and undergoes ozonation. In so doing, the resistant organic substances such as pesticides are destroyed, and the rest of pathogenic bacteria and viruses are inactivated. Then, water is softened, if necessary, and its pH should be adjusted to the desired level. 

To create a nonzero contact angle in a gas-liquid-solid particle system where the liquid normedly wets the particle (e.g. water and most mineral matter), surface active species called collectors are dispersed in the liquid for adsorption on particle surfaces. In aqueous systems, addition of surfactants such as long-chain fatty acids, and their adsorption on particle surfaces, make the surface hydro-phobic enough, leading to a nonzero 0. Equation (3.3.40b) may be utilized here to study how the various interfacial tensions are changed by changes in the hulk concentrations of the added surfactants (Fuerstenau and Healy, 1972). 

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