Study On Upgrading Of Low-quality Oil Shale By Dense Gas-solid Fluidized High-density Separation

Energy is the cornerstone of social operation,development and human survival.The large-scale exploitation of coal and oil,which are conventional fossil energy sources,is about to be exhausted.Therefore,it is necessary to develop unconventional energy resources,among which oil shale has high application value,and its exploitation and utilization are also increasing gradually.Affected by factors such as the distribution of oil shale resources,water resources,and the environment in China,there are many problems in the industrial application of wet-separation oil shale technology,and research on efficient dry fluidized separation of oil shale has become an urgent need.In this paper,combining the research status of low-quality oil shale upgrading and the occurrence and structure characteristics of inorganic minerals in oil shale,a high density microbubble is formed uniformly under the driving of an updraft using a mixed dense medium of ferrosilicon powder and oil shale mineral powder.Based on the effect of the actual separation material deposition components on the separation effect,the effective quality enhancement mechanism of high-density separation under the dense fluidization of low-quality oil shale is realized.The particle size optimization of ferrosilicon powder,the physical properties parameters of oil shale powder and the grading rule of two kinds of mixed particles were studied.The dominant particle grade of the mixed weighting is determined,and the mixing mechanism of the weighting of ferrosilicon powder and oil shale powder is clarified.Combined with the theory of gas-solid two-phase,the expansion law of mixed dense medium in the fluidized bed was explored.The density distribution characteristics and bed stability of the mixed dense medium gas-solid high density separation fluidized bed were studied.The operating conditions of density range control of dense high density fluidized bed were defined.At the same time,the time-domain characteristics of the bed density of the high-density separation fluidized bed were studied.With the increase of the operating gas velocity,the fluctuation of the bed density intensifies,the bed density distribution was uneven,the fluctuation amplitude was large,and the fluctuation period was long.By studying the effect of the interaction of deposition components and gas kinetic energy on the bed characteristics under different operating conditions,the synergistic effect of deposition components on improving the fluidization state was clarified.The time-domain and frequency-domain characteristics of the pressure drop signal fluctuation in the bed under the sedimentary layer were analyzed,and the disturbance behavior of the bed pressure in the high-density separation fluidized bed was described.Based on the influence of deposition components on the bed density fluctuation,the disturbance behavior of operation parameters of deposition components on the bed stability of high-density separation fluidized bed was revealed by orthogonal test.The corresponding mathematical model between the stability of the bed and the characteristics of the sedimentary layer is established,and the optimal configuration scheme of the sediment components is determined.Based on the above research,the Box-Behnken response surface method was used to study the interaction and significance of oil shale sedimentary components on the separation effect of low-quality oil shale under different operating conditions,and the best operating range of dense high-density separation fluidized bed for improving the quality of low-quality oil shale was determined.In the experiment,the best separation effect was that concentrate yield was 34.44%,oil content was 9.34%,tailings yield was65.56%,oil content was 1.18%,separation density was 2.48g/cm~3,and separation deviation E was 0.053.This paper includes 47 figures,16 tables and 112 references.