LAUSR

Abstract The raw materials of this study were oilfield sludge and the tailings extracted from the oil sands of Yumen. The mineral composition and particle size distribution were characterized by X-ray diffraction and gradient screening. In this study, we put forward a new process of oil sludge and oil sand tailings blending extraction. Tailings mainly contained high crystallinity of quartz and calcium carbonate. Tailings with particle size greater than 75 μm accounted for more than 95%. Oil sludge mainly contained clay minerals. Through the co-extraction experiment of different proportions of oil sludge and tailings, we can get the best condition of blending extraction. The results showed that m (tailing oil sands): m (oil sludge) = 0.5, v (solvents): m (sample) = 2, temperature 60 °C and contact time 20 minutes were the optimum technological conditions. Under the optimum conditions, the yield of the first stage co-extraction was up to 81.8%. The total yield of secondary co-extraction oil was up to 89.4%. This study overcame the problem of low yield of oil extracted from oil sludge.