摘要：In order to enhance bitumen recovery from carbonate asphalt rocks, acid-washed process (hydrochloric acid) w ith bio-surfactants-assisted enhanced was put forward. The acid-washed process for carbonate asphalt rocks was optimized by single factor experiment, and the optimal conditions were as fo llows: the hydrochloric acid concentration was 14.8%, the stirring rate was 600 rpm, the temperature was 60°C and the reaction time was 4 h. The metal ions concentrations decreased w ith the increase of pH. As the results, the bitumen recovery was 96.7% and the B/S was 2.52 at the optimal condition. SEM (Scanning Electron Microscope) analysis indicated that most carbonate mineral surfaces are covered w ith b itumen in carbonate asphalt rocks, so the B/S was low for carbonate asphalt rocks by using acid-washed process only. In order to solve the lim itation, the sophorolipid was used to enhance the acid-wash process. The bitumen recovery was increased from 96.7% to 98.7% and B/S was increased from 2.52 to 3.07 w ith the sophorolipid concentration increased from 0 to 1000 ppm. To study the effect of sophorolipid on enhancing acid-washed process, zeta potential and AFM (atomic force microscope) measurements were used. Zeta potential measurement showed that bitumen and CaCo3 have strong attractive force in deionized water, but they have strong repulsive force in sophorolipid solution. The AFM measurements showed that the adhesive force between bitumen and carbonate decreased w ith the increasing concentration of sophorolipid. The sophorolipid could reduce the interaction of oil-solid, and promote the hydrochloric acid react w ith minerals, leading to increased B/S significantly.
