Wettability contrast

A procedure is described for the beneficiation of Green River oil shale, based on the wettability contrast between the... 

If the wettability between the different kinds of particles does not sufficiently differ to allow such a separation, additives may be supplied that selectively adsorb to enhance the wettability contrast. Such additives are called collectors. Further improvement may be obtained by adding frothing agents that stabilize the froth layer containing the removed particles. 

The reagent can be used most advantageously on aluminium oxide, silica gel, kieselguhr. Si 50000, cellulose, diol and water-wettable RP 18 layers there is less contrast in color on strongly hydrophobic RP 18 phases. NH2 and polyamide layers are not suitable because the iodine is too strongly bound and the whole layer is colored green-yellow. 

The objective of this work is to determine the surface concentration of the hydroxyl groups of cellulose and PVA films utilizing their chemical modification. We chose these polymers mainly because the hydroxyl group is their sole functional group. Recently we have reported that a cellulose film is more excellent in wettability towards water than PVA, though cellulose is insoluble in water, in contrast to PVA(4). Since only the chemical composition of the surface must be responsible for water... 

The problem here consists in listing the material parameters because, in activated sludge, they fluctuate strongly (much in contrast to ore flotation). Surely, the degree of hydrophobicity (wettability) of the particle surface (contact angle, ) will be of importance. Furthermore, the pH value, the concentration of the flocculant (poly-electrolyte), cF, the portion of solids, [Pg.30]

Attempts to improve wetting by non-reactive pure metals such as Cu by the addition of ferrous metals such as Ni or Fe have been unsuccessful (Naidich 1981). In contrast, improvements in wetting have been achieved by adding carbide-forming elements such as Cr or Ti. Additions of Cr to Cu above a critical value of the molar fraction of Cr, XCr, produce a sharp wetting transition (Figure 8.10) owing to the formation of a continuous layer of wettable Cr carbides in accord with the reaction ... 

Many of the insecticides sold for garden use are in the form of wettable powders because there is very httle chance that this formulation will bum foliage, even at high concentrations. In contrast, the original carrier in emulsifi-able concentrates is usually an aromatic solvent, which in relatively moderate concentrations can cause fohage burning at temperatures above 32.5°C (90°F). 

Van den Mooter et al. prepared solid dispersions of tamazepam in PEG 6000 and polyvinylpyrrolidone K30 (PVP K30) by the fusion (melting) and cooling process. In contrast to the very slow dissolution rate of pure temazepam, the dispersion of the drug in the polymers enhanced the dissolution rate considerably. This can be attributed to improved wettability and dispersibility and a decrease of the crystalline fraction of the drug. 

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