Mineralization electrochemical properties

Zhuang, J. and Yu, G.-R. (2002) Effects of surface coatings on electrochemical properties and contaminant sorption of clay minerals. Chemosphere, 49(6), 619-28. 

Following Lavoisier, chemists had a set of rules and a provisional list of elements to work with. Later, using Dalton s atomic theory and his laws of combining proportions, chemists were able to determine atomic weights and to arrive at molecular formulas indicating the nature and number of the atoms in a molecule. Molecules, the smallest part of a compound that possessed the chemical properties of that compound, could then be classified. Berzelius s classification of mineral compounds rested upon his discoveries about the electrochemical properties of atoms, an explanatory notion grafted onto Dalton s simple atomic theory. Chemists were able to establish research programs based... 

The major mineral groups commonly found in soil include (1) aluminosilicates, (2) oxides, and (3) organic matter. Through their surface electrochemical properties, these soil minerals control adsorption, transformation, and release behavior of chemical constituents (e.g., nutrients and contaminants) to water or soil solution. Soil-surface electrochemical properties vary between soil types and depend on factors such as parent material, climate, and vegetation (Table 3.1). Generally, the overall makeup of soil is (Fig. 3.1)... 

Harsin, A. E. and V. P. Evangelou. 1989. The electrochemical properties of soil minerals. Influence on physico-chemical stability. In S. S. Augustithis, Ed. Weathering Its Products and Deposits. Theophrastus Publications, S.A., Athens, Greece, pp. 197-229. 

Leroy, P. and A. J. Revil. 2003. A triple-layer model of the surface electrochemical properties of clay minerals. J. Coll. Interface Sci. 270, 371-380. 

Braggs, B. et al.. The effect of surface modification by an organosilane on the electrochemical properties of kaolinite. Clays Clay Miner., 42, 123, 1994. 

The above clearly shows the predominant role played by the electrochemical properties of the minerals in determining surfactant adsorption on minerals and their flotation (Somasundaran and Agar, 1967). 

Ores—Part I Electrochemical Properties of Some Minerals of the Apatite Group Pan II Electrochemical Phenomeon at [be Caicite/Aquoons Interface, Trans. SME/AIME, 258, 168 (1975). 

Surfactant adsorption on saltlike minerals, such as calcite and dolomite, is a more complex process and is less understood than adsorption on oxide surfaces. These minerals are relatively soluble and when in contact with an aqueous medium develop an interfacial region of complex composition (41—43). In addition to the two mentioned mechanisms of adsorption, covalent bonding, salt formation between surfactant and lattice ions at the solid surface, ion exchange of surfactant with lattice ions, and surface precipitation have been suggested as adsorption mechanisms (36, 43—47). The dissolution products of sparingly soluble minerals may interact with the surfactant, precipitate or adsorb at the solid surface, or lead to mineral transformations that affect surface composition and electrochemical properties (46, 48—52). All these factors can be expected to influence surfactant adsorption. 

In mixed mineral systems, dissolution—precipitation equilibria may lead to mineral transformations that can influence surface electrochemical properties (48—50, 52). 

C.E. Marshall and C.A. Krinbill, The electrochemical properties of mineral membranes. 

The mobility of trace elements during weathering is determined, first by the stability of the host minerals, and second by their electrochemical properties. The association of trace elements with minerals in soils reflects often their origin, and this is an important factor in their distribution and behavior. Several chemical and physical processes are involved in weathering of both biotic (living organisms and their decomposition) and abiotic origins. Basic processes can be characterized as follows ... 

Elving et al. [132] were the first to investigate the electrochemical properties of sulfur dioxide. Unfortunately, their study was restricted to mineral electrolytes, which in this solvent have very limited solubility and, therefore, did not yield electrolytic solutions with sufficient conductivity for the usual electrochemistry. This problem was solved some time later by using the tetrabutylammonium cation instead of metal cations [133-135]. 

M.A Maguire and T.L. Yau. 1986. Electrochemical properties of zirconium in mineral acids. Corrosion 86, Paper No. 265, Houston, TX NACE International. 

Electrorefining of silicon from wastes is economically worthwhile, compared with the thermic extraction of Si from mineral ores, which requires far higher temperatures for treatment, and so, a higher cost. This article should open the way for an industrial application of the electrorefining process. Furthermore, worthy of note is that we used the electrochemical properties of Si compounds to measure the fluoroacidity of molten salts with good accuracy and the methodology can be extended to other systems to define the basic properties of a molten solvent, by its complexing effect on the stability of a volatile compound. 

The recovery of petroleum from sandstone and the release of kerogen from oil shale and tar sands both depend strongly on the microstmcture and surface properties of these porous media. The interfacial properties of complex liquid agents—mixtures of polymers and surfactants—are critical to viscosity control in tertiary oil recovery and to the comminution of minerals and coal. The corrosion and wear of mechanical parts are influenced by the composition and stmcture of metal surfaces, as well as by the interaction of lubricants with these surfaces. Microstmcture and surface properties are vitally important to both the performance of electrodes in electrochemical processes and the effectiveness of catalysts. Advances in synthetic chemistry are opening the door to the design of zeolites and layered compounds with tightly specified properties to provide the desired catalytic activity and separation selectivity. 

The first CNT-modified electrode was reported by Britto et al. in 1996 to study the oxidation of dopamine [16]. The CNT-composite electrode was constructed with bro-moform as the binder. The cyclic voltammetry showed a high degree of reversibility in the redox reaction of dopamine (see Fig. 15.3). Valentini and Rubianes have reported another type of CNT paste electrode by mixing CNTs with mineral oil. This kind of electrode shows excellent electrocatalytic activity toward many materials such as dopamine, ascorbic acid, uric acid, 3,4-dihydroxyphenylacetic acid [39], hydrogen peroxide, and NADH [7], Wang and Musameh have fabricated the CNT/Teflon composite electrodes with attractive electrochemical performance, based on the dispersion of CNTs within a Teflon binder. It has been demonstrated that the electrocatalytic properties of CNTs are not impaired by their association with the Teflon binder [15]. 

Abstract This chapter reviews the development of froth flotation achieved in the past one hundred years and accounts for the achievements of the theory of flotation of sulphide minerals in four aspects, which are the natural flotahility of sulphide minerals, the role of oxygen in the flotation of sulphide minerals, the interaction of collectors with sulphide minerals, the effect of the semi-conductor property of sulphide minerals and electrochemical behaviors in the grinding system. Furthermore, the purpose of this book is revealed in the end. 

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