High float emulsions

Chem. Descrip. Tall oil fatly acid CAS 61790-12-3 EINECS/ELINCS 263-107-3 Uses Emulsifier for soap sol ns. for high float emulsions Properties Liq. sp.gr. 0.943 dens. 7.87 Ib/gal vise. 90 cps pour pt. 4 C flash pt. 191 C... 

Uses Asphalt emulsifier producing high float emulsion when used with Indulin 201 or 202 as emulsifier... 

Uses Emuisifler for anionic rapid and medium-setting asphalt emulsions including high-float emulsions... 

Emulsification. This is a water-in-oil process in which water is incorporated into the floating oil. Such emulsions, which may contain from 20 to 80% water, are often very viscous and referred to as mousse. Mousse formation is highly dependent on oil composition. High levels of asphalt-type compounds, as well as waxes, appear to promote the formation of these emulsions. Ocean turbulence also accelerates mousse formation, although a fully developed, stable emulsion may be formed from some oils under relatively quiescent open-water conditions. Early treatment of spilled oil with chemical dispersants is an excellent way to prevent emulsification. 

Emulsions are usually formed, for instance, due to over-agitation, interfacial tension, low-density difference, or the inherent nature of the compounds involved. In our case the extraction problems were supposed to stem from the high density of both substrate and product (<5 > 1) combined with their high concentrations in the reaction mixture, the emulsifying power of the enzyme, and loose solid fines that floated at the interface. In some very highly concentrated experiments (cf. Section 5.4.2) the organic phase had an even higher density than the aqueous phase. 

Draft tubes. The return flow to an impeller of any type approaches the impeller from all directions, because it is not under the control of solid surfaces. The flow to and from a propeller, for example, is essentially similar to the flow of air to and from a fan operating in a room. In most applications of impeller mixers this is not a limitation, but when the direction and velocity of flow to the suction of the impeller are to be controlled, draft tubes are used, as shown in Fig. 9.6. These devices may be useful when high shear at the impeller itself is desired, as in the manufacture of certain emulsions, or where solid particles that tend to float on the surface of the liquid in the tank are to be dispersed in the liquid. Draft tubes for propellers are mounted around the impeller, and those for turbines are... 

An original technological solution for phosphate separation has been proposed in [157]. The typical flow-sheet requires rather high consumptions of anionic collectors, e.g. fatty acid soaps. The authors have proposed a two-step flow-sheet in which fine particles are first floated with a minimum aminoacid consumption. The concentrate from prefloat is then floatated with a fatty acid/fuel oil emulsion. As a result, a phosphorite concentrate is produced which contains about 30 % P2O5, and the P2O5 recovety is over 93%. 

---