Interactions reagent-mineral

Plaksin, I.N., Study of Superficial Layers of Flotation Reagents on Minerals and the Influence of the Structure of Minerals on their Interactions with Minerals, International Mineral Processing Congress, paper 13, London, 1960. 

Other Interaction Processes. The selectivity of flotation reagents in a pulp and their functions depend on their interactions with the mineral phases to be separated, but other physicochemical and hydrodynamic processes also play roles. AH adsorption—desorption phenomena occur at the sohd—hquid interfacial region. Surface processes that influence such adsorptions include activation and depression. Activators and depressants are auxiUary reagents. 

In chemical syntheses under the action of microwave irradiation the most successful applications are necessarily found to be the use of solvent-free systems [6], In these systems, microwaves interact directly with the reagents and can, therefore, drive chemical reactions more efficiently. The possible acceleration of such reactions might be optimum, because they are not moderated or impeded by solvents. Reactions on solid mineral supports and, in turn, the interaction of microwaves with the reagents on the solid phase boundary, which can substantially increase the rate of the reactions, are of particular interest [7]. 

Abstract The flotation mechanism is discussed in the terms of corrosive electrochemistry in this chapter. In corrosion the disolution of minerals is called self-corrosion. And the reaction between reagents and minerals is treated as inhibition of corrosion. The stronger the ability of inhibiting the corrosion of minerals, the stronger the reagents react with minerals. The two major tools implied in the research of electrochemical corrosion are polarization curves and EIS (electrochemistry impedance spectrum). With these tools, pyrite, galena and sphalerite are discussed under different conditions respectively, including interactions between collector with them and the difference of oxidation of minerals in NaOH solution and in lime. And the results obtained from this research are in accordance with those from other conventional research. With this research some new information can be obtained while it is impossible for other methods. 

Grinding is essential for the liberation of sulphide minerals in order to achieve effective flotation. The grinding process, however, may also have a various effects on the flotation separation because of the galvanic interactions among the grinding media and the different minerals due to the high redox activity of sulphide mineral and iron media as well as thio-reagents. 

Abstract In the light of quantum chemistry, sulphide minerals and the interaction of them with reagents are investigated in this chapter. With the density functional theory pyrite is first researched including its bulk properties about energy band and frontier orbitals and the property of FeS2 (100) surface. 

Microwave heating has proven to be of benefit particularly for reactions under dry media (e.g., solvent-free conditions) in open vessel systems (i.e., in the absence of a solvent, on solid support with or without catalysts) [4]. Reactions under dry conditions were originally developed in the late 1980 s [51], but solventless systems under microwave conditions offer several additional advantages. The absence of solvent reduces the risk of explosions when the reaction takes place in a closed vessel. Moreover, aprotic dipolar solvents with high boiling points are expensive and difficult to remove from the reaction mixtures. During microwave induction of reactions under dry conditions, the reactants adsorbed on the surface of alumina, silica gel, clay, and other mineral supports absorb microwaves whereas the support does not, and transmission of microwaves is not restricted. Moreover, microwaves can interact directly with reagents and, therefore, can more efficiently drive chemical reactions. The possible accelerations of such reactions are expected... 

Richardson, P. E. Edelstein, D. L., "The Physical Chemsitry of Mineral-Reagent-Interactions in Sulfide Flotation," USBM Information Circular 8819, 1978, p. 72. 

Metal concentrations are determined using molecular spectrophotometric, atomic spectrometric, and electrochemical techniques. All of these require samples to be homogenous, or at least to contain the smallest possible amounts of organic matter that could interfere with the metal determination by interacting with the metal ions and the analytical reagents. Traditionally, decomposition of the sample in elemental analysis requires it to be mineralized in order to remove the organic content.1 Sample decomposition for total element determination therefore appears to be the recommended procedure on every occasion. 

Acetals are readily hydrolyzed by dilute mineral acids however, the yields are not always satisfactory. These substances are not affected by alkaline reagents. The sensitive JZ-glyceraldehyde acetal is converted to its aldehyde in 80% yield by the action of dilute sulfuric acid under mild conditions. Other procedures are illustrated by the treatment of acetals which are formed by the interaction of Grignard reagents and orthoformic esters (method 165). 

P. K. Naik, P. S. R. Reddy, and V. N. Misra, Interpretation of interaction effects and optimization of reagent dosages for fine coal flotation. Internal. J. Mineral Processing 75(1-2) (2005). 

Borisov, V.M., Method of physicochemical assessment of interaction of reagents with the surface of mineral grains in flotation, Khim. Prom. 19, 336, 1954. 

In this procedure the synthesis mixture is reduced to three basic components silica (solid), surfactant (halide) and hydroxide as mineralizer (tetramcthylammonium hydroxide, TMA-OH), all supplied as the convenient reagents. The key parameter is the essentially stoichiometric 1 1 ratio of surfactant and hydroxide, which allows treatment of the product (MCM-41) as formally a surfactant silicate resulting from interaction between silica and surfactant hydroxide. The latter reagent is not a conveniently available or cost effective one to use. Consequently the most desirable surfactant source is its halide salt. The presented... 

Flotation of sparingly soluble minerals such as calcite has not been well understood. Recently, Somasundaran et al. (1985, 1991) and Hu et al. (1995) have done some systematic work on the dissolution equilibria of salt-type minerals in solutions and their effects on the selectivity in flotation. Thus they found that surface conversion of mineral surfaces and precipitation on surfaces of minerals due to interactions among dissolved mineral species and the reagents are the major mechanisms that should be considered in flotation systems of sparingly-soluble minerals. 

Mineral-surfactant equilibria. Mineral-surfactant equilibria determine adsorption of various surfactants on minerals, hemimicellization, interactions among dissolved mineral species and reagents and electrochemical interactions. The optimum conditions for mineral-surfactant interactions as well as flotation can be calculated from data for such parameters as the solubility product and complex formation constants and species distribution diagrams with the helps of plots of logC-pH, AG°-pH, log/3, iih-pH, etc. 

Reagents used in flotation, collectors, frothers, depressants, flocculants and inorganic modifiers can interact with each other in the flotation pulp and at the mineral-solution interface. The chemical equilibria involved in these interactions and the nature of the products will have a significant effect on their adsorption and the resultant flotation processes. 

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. 

Hydrophobic association energy, mineral surfaces. In turn, the proportion of hydrophilic and hydrophobic groups in the flotation reagents is relevant in the determination of 0 value. 

In this chapter, the interaction forces responsible for adsorption at solid-Uquid interfaces and the microstructure of the adsorbed layer that influences the flotation and flocculation processes are discussed. Surface and bulk inta actions between the flotation reagents and dissolved mineral species and their solution equilibria are described using multi-pronged experimental and diagrammatic schemes. Electrochemical equilibria of mineral-flotation agent are also discussed. 

Various types of flotation agents are used for selective hydrophobization of minerals in froth flotation. Oleic acid is the most common collector used commercially in the flotation processes of salt-type mineral because of its low cost and availability. In the case of complex ores containing similar constituent minerals such as calcium carbonate and calcium phosphate, the selectivity of flotation using oleate as a collector is usually poor and the reagent consumption is generally high (Lawver et al., 1982 Hanna and Somasundaran, 1976). In order to achieve improvements in the separation, it is helpful to identify various interactions between the dissolved mineral species and the oleate species. These interactions are discussed below. 

Geochemical classification of mineral elements and interaction with reagents ... 

The bonding characteristics determine the properties of the minerophilic and hydrophilic groups. The selectivity of the mineral-reagent interactions can be estimated using a bonding criterion. 

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