| Coal-bed methane is a clean,high-quality energy and chemical raw material that has risen in the international arena in the past 20 years.In order to accelerate the development and utilization of coal-bed methane resources,effectively curb coal mine gas accidents,and achieve industrialization and scale of coal-bed methane ground development,it is necessary to prepare a suitable ceramic fracturing proppant for coal-bed methane wells.At present,the use of solid waste,industrial waste preparation of ceramic proppant is one of the hot spots of ceramic proppant research,coal gangue is the process of coal mining and coal washing process discharge of solid waste,not only large emissions,serious pollution,and coal gangue comprehensive utilization of less,utilization rate is low,coal gangue preparation of ceramic proppant is an important way of coal gangue comprehensive utilization.Although,gangue raw material can be used directly to prepare ceramic proppant,but because of its poor performance,it is difficult to meet the buried in 2000m to shallow coal bed methane mining,in order to solve this problem,we carried out precalcined coal gangue preparation of coal bed methane well with ceramic proppant research,the main findings are as follows.(1)The physical and chemical changes of gangue in Yangquan area under different calcination temperatures were studied,and the results showed that:when the calcination temperature was increased from 25?to 1500?,the total weight loss of gangue was 20.19%,and there were obvious heat absorption phenomenon of gangue at 517?,1120?and 1333?,and obvious exothermic phenomenon appeared at 1319.5?.Combined with the XRD results of the gangue at different calcination temperatures,it can be seen that:the gangue in25??385?off adsorption water,400??1200?off structure water,1200??1500?within a large number of Al-Si spinel and mullite generation.From the microstructure analysis of the gangue,it is known that the structure of the gangue is more lax at 700?and 800?.(2)The ceramic pellet proppant was prepared using coal gangue and bauxite as the main raw materials and potassium feldspar as the sintering aid.The effects of the pre-calcination temperature of coal gangue and the addition of coal gangue active material on its performance were studied.The results show that:when the pre-calcination temperature of the gangue is 800?,the performance of the ceramic support agent is the best,52 MPa closed pressure crushing rate of 3.35%,42MPa closed pressure crushing rate of 7.19%,bulk density of 1.34g/cm~3,apparent density of 2.6g/cm~3,gangue in 800?after calcination produced a large number of lattice defects,strengthen the diffusion effect,and promotes sintering.When the addition of coal gangue active material is 20%wt.%,the best performance of ceramic proppant,its bulk density of1.36g/cm~3,apparent density of 2.6g/cm~3,crushing rate of 3.66%at 42MPa closed pressure and 7.97%at 52MPa closed pressure,at this ratio,the aluminum-silica ratio of ceramic proppant and the liquid phase content at high temperature are compatible The ratio of aluminium to silicon ratio and the liquid phase content at high temperature were compatible with the ratio,which promoted the formation of mullite bird's nest and improved the crushing resistance of the ceramic proppant.(3)The effect of sintering temperature on the performance of ceramic proppant was studied,and the difference in performance of three kinds of ceramic proppant was compared.The results show that:the ceramic proppant prepared by sintering 60wt.%bauxite,20wt.%potassium feldspar and 20wt.%coal gangue active material as raw materials not only has excellent performance,but also has lower sintering temperature,uncalcined coal gangue and bauxite,which has a larger lattice energy and a more stable structural state,is not conducive to sintering. |
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