The Effect Of Lithology And Asphalt Properties On The Efficiency Of Hot Alkaline Water-based Separation For Oil Sand Bitumen

Oil sand is an important unconventional oil and gas resources,it is very important for the alleviation of energy supply crisis in China to explore oil sand resources and achieve the large-scale industrial production of oil sand.The recovery of asphalt is the key issue in the use of oil sands resources.There are many methods for the recovery of oil asphalt.At present,the most commonly used method for the separation of water-borne oil sand is hot alkaline water-based separation.The recovery efficiency of such separation method is controlled by many factors,including temperature,pH value,ventilation,adding additives external factors and lithological factors,asphalt properties and other internal factors.There are many researches on the external factors of hot alkaline water-based separation for oil sand.However,the research on the internal factors is rarely reported.The status of oil sand resource in China and Canada was compared,and the geochemical characteristics of oil sand in different regions of China were analyzed in this paper.It was found that the distribution,grade,mineral composition of oil sand in China is very different from that of Canada.The composition of oil minerals in different regions of China is relatively complex,the content of clay minerals is high,and the composition of asphalt oil in different areas is also different,especially asphaltene content.Based on the study of the mechanism between asphalt and minerals in oil sand and the factors that restrict the separation process,the influences of lithological factors and asphalt properties on the efficiency of hot alkaline water-based separation for oil sand bitumen were further studied in this paper.Meanwhile,laboratory orthogonal experiments were conducted to study the effects of the types of minerals,the size of the minerals,the composition of minerals and the property of asphalt on the separation of oil sand.The data of aging experiment were analyzed,it was found that the optimal timeof bitumen aging of simulation experiment in laboratory was about 20 days and the wettability had an influence on the recovery efficiency of bitumen Compared to lubricated oil sands,hydrated oil sands were more suitable to use hot alkaline water-based separation.The results laid a theoretical foundation for further research on investigating the influence of lithology and the bitumen properties on the recovery efficiency of bitumen through hot alkaline water-based separation.The results of this paper was showed that the separation efficiency of the hydrated oil sand was effected by the lithological characteristics.The efficiency of oil sand hot water extraction were all affected by the differences in the size of mineral particles,the composition of mineral and the content of mineral.The smaller the particle size of solid mineral particles,the poorer the asphalt flotation effect,the oil sand asphalt mining industry value was also decreased.The recovery of bitumen is poor when there are large quantities of mineral particles in the oil sand that are less than 44?m.The recovery of the asphalt was also affected by the type change of the clay minerals in oil sand,the difference in clay mineral composition will influence the efficiency of oil sand separation.In addition,the higher the content of clay minerals,the lower the recovery rate of oil asphalt;When the content of the clay minerals was greater than 15%,the efficiency of the oil sands was obviously reduced.The effect of montmorillonite content on the separation efficiency of hot alkaline water-based separation for oil sand bitumen is the most significant,among the three clay minerals,montmorillonite,illite and chlorite.Meanwhile,the recovery of flotation asphalt was also influenced by the asphaltene content in asphalt oil,the higher the content of asphaltene,the lower the content of flotation asphalt.Based on the study of the lithological characteristics and asphalt properties of typical oil sands in China,the study in this paper may provide some theoretical and technological supports for the oil sand exploitation in China in the future.