Hydrophobic mineral phase

In Fig. 30, a three-dimensional model is presented in which only the organic phases are shown. Hexagonal plates of MM alternate with pleated sheets of CP. The hydrophobic sides of MM are facing each other and encase the mineral phase. The relationship between hydrophobic bonding and accessible surface area in proteins, and the effect of polar and non-polar side groups on free energy values has recently been discussed246. For informations on hydrophobicity in protein systems see Refs.247-252. ... 

The zeolite-carbon adsorbents from mineral-carbon adsorbents group are novel and exhibit not quite well recognized properties with their unique, modified porous structure. The characteristic structures for zeolite, active carbon and intermediate structure exist in these materials. Such a structure results fi-om the modification of a surface of a mineral matrix by depositing carbon material. The efifectivity of enrichment of the structure of zeolite-carbon adsorbents (in relation to crystalline zeolite structure) in hydrophobic micropores (0.4 - 2 nm) and macropores (above 50 nm) is proportional to the fi action of carbon phase. Such combination of hydrophilic properties of mineral phase and hydrophobic properties of organic phase results in various sorptive properties of the material and the range of their application can be consequently extended. Additionally, the chemical resistance of these adsorbents for their exploitation in aggressive conditions takes place. 

Sorption of organophosphorus insecticides to soil particles depends primarily on compound hydrophobicity and the fraction of natural organic matter (NOM) in the soil (19, 20). Mineral phases appear to exert more influence on sorption processes for organophosphorus insecticides than for more extensively investigated hydrophobic organic compounds (e.g., DDT). The sorption of most hydrophobic organic compounds is dominated by NOM when the fraction of soil organic matter, exceeds 0.002 (21). For... 

Outside of foods, the presence of colloidal particles significantly influences many processes. For example, during bitumen extraction from oilsands, oil droplets in a continuous water phase are stabilized by hydrophobic mineral particles. Removal of oil droplets is important to increase oil yield and protect the environment, yet the capital and operating costs are high [6]. In pharmaceuticals, partially solid emulsions can used for topical delivery [7]. And, as will be discussed, colloidal particles substantially influence the formation and stability of many food emulsions. Although it describes generalities on how colloids can affect emulsion properties, this chapter is primarily concerned with the application of fat crystals and their effects on emulsion stability. 

The use of a water-immiscible Hquid to separate coal from impurities is based on the principle that the coal surface is hydrophobic and preferentially wetted by the nonaqueous medium whereas the minerals, being hydrophilic, remain suspended in water. Hence, separation of two phases produces a clean coal containing a small amount of a nonaqueous Hquid, eg, oil, and an aqueous suspension of the refuse. This process is generally referred to as selective agglomeration. 

The amphiphilic nature of dissolved humic substances (DHS) lends them the ability to associate with both hydrophobic organics and polar or ionic species [62-64]. Inorganic ions or mineral colloids in solution will interact with the electrically active surface of humic material in solution or in the solid phase according to the same bonding forces which lead to the association between SP0M and the solid mineral matrix. Humic matter in water is associated with... 

Hydrophobic pollutants such as PCBs often partition into lipid rather than into water. The K0w measures this partitioning. This coefficient provides an indication of the degree to which a pollutant accumulates into fatty tissues and any organic phase. This coefficient is especially useful for determining the release of PCBs from mineral oil transformer fluids, and Hawker and Connell [391] pro-... 

Environmental releases of PCBs often accompany releases of carriers from utility equipment. An example would be mineral oil released from oil filled transformers. When PCBs are present in a mineral oil-PCB mixture the aqueous solubility of the PCBs is reduced significantly. Two factors play a role in this reduction partitioning of the lipophilic (oil-loving) PCBs into the oil phase, and the reduced interaction of the PCBs with precipitation or groundwater caused by the hydrophobic nature of the oil matrix. Interpretation of aqueous PCB concentrations in the field must consider the presence of dissolved organic carbon (DOC) [382,386,397,403]. 

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. 

As is known to all, the flotation mechanism of sulphide minerals can be explained based on electrochemistry because sulphide minerals have the semiconductor character and a series of electrochemistry reaction occurring in solution. After these reactions, the surface of sulphide minerals changes and forms a new phase. We called it as self-corrosion of sulphide minerals. As before, the essence of the reaction between the collector and the minerals is the formation of the hydrophobic entity on the mineral surface, and then minerals can be floated. We can find that the reaction between the collector and the minerals is similar to the depression on mineral self-corrosion. In the corrosion, we called this effect as inhibition, and this kind of reagent is an inhibiting reagent. There are many studies on corrosion, especially its research method and theory. Thus, we can get some new information on the mechanism of sulphide flotation from corrosive electrochemistry. 

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