Bitumen envelopes

The first three methods involve water as the separating medium. These are based on the well known observation that the bulk of the sand, on the order of 99%, is not in direct contact with the bitumen but is "protected by an envelope of water. On adding further water, the sand is "liberated into the bulk water phase, and the bitumen, which was previously interspersed among the grains of sand, retracts into discrete flecks. These flecks are usually small, and having approximately the same density as water, remain dispersed in the water as an oil-in-water emulsion. 

In the process (Figure 8-10), the preheated feedstock (which may be whole crude, atmospheric residuum, vacuum residuum, or bitumen) is injected into a stream of fluidized, hot catalyst (trade name ArtCat). Complete mixing of the feedstock with the catalyst is achieved in the contactor, which is operated within a pressure-temperature envelope to ensure selective vaporization. The vapor and the contactor effluent are quickly and efficiently separated from each other and entrained hydrocarbons are stripped from the contaminant (containing spent... 

The virgin bitumen and fractions were characterized by 13C NMR. Results shown in Figure 1 show that the spectra of the maltenes and the virgin bitumen are virtually superimposable. The high resolution spectra reveal several resolved peaks in the saturates region attributable to n-alkyl species, some of which are of notably lower intensity in the maltenes spectrum, but in general, the vast majority of the saturates carbon (>80%) is found under the envelope and is probably due to complex alicyclic and/or isoparaffin structures. These results are consistent with an earlier observation (1) that saturated hydrocarbons from Uinta Basin bitumen are high in naphthenes and low in free paraffins. 

Tar sand is a mixture of sand, water, and bitumen with the sand component occurring predominantly as quartz. The arrangement of the sand, water, and bitumen has been assumed to be an arrangement whereby each particle of the sand is water-wet and a film of bitumen surrounds the water-wetted grains. The balance of the void volume is filled with bitumen, connate water, or gas fine material, such as clay, occurs within the water envelope. 

The erosion resistance of the soil may be increased by raising the cohesion of the soil aggregates this may be done by treating the soil with binding substances [507]. Such substances include cellulose and its derivatives (lignin, humic acid), bitumen, peat cement, and various structure-forming substances from plant residues. The adhesive substances envelop the soil particles. The layer so formed, a few microns thick, imparts the quality of tacki-... 

Two horizontal disks of bitumen, cast in shouldered brass rings, are heated at a controlled rate in a liquid bath while each supports a steel ball. The softening point is reported as the mean of the temperatures at which the two disks soften enough to allow each ball, enveloped in bitumen, to fall a distance of 25 mm (1.0 in.). 

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