Research On Preparation Of Ceramisite Proppant Mainly On Purple Sand

The ceramisite proppant material was prepared by purple sand from Xiananru Purple Sand Mine at Yangquan District in Shanxi Province as main raw materials, and the third-rate bauxite from Changqing Proppant Co.,Ltd as auxiliary material. First, I analysed the properties of raw materials, such as chemical components, phase components, microstructure and particle size distribution, by chemical means and testing equipment. Secondly, combined with production experience and pre-explore, I found out the sintering temperature of ceramisite proppant made by pure purple sand and studied the impact of sintering temperature had on phase composition, microstructure, bulk density, apparent density and crushing ratio. I also adjusted the experimental formulations to explore the ceramisite proppant that meet the standard requirements, which need the minimum bauxite addition, and its corresponding sintering temperature. I studied the addition of bauxite impact on phase composition, microstructure and physical properties of the ceramisite proppant.Finally, I researched the impact of sintering temperature had on phase composition, microstructure and physical properties of the ceramisite proppant that made by purple sand added in bauxite.The main results are as follows:(1)The chemical components of purple sand from Xiananru Purple Sand Mine were SiO2(51.12wt%)、Al2O3(29.26wt%)、Fe2O3、Ca O、Na2O and TiO2,Al/Si=2:3, main phases were quartz, kaolinite, mica and albite, its average particle size was 10.43 ?m(D50=10.43 ?m), and its particle size distribution was centralized; The chemical ingredient of bauxite that used in production was Al2O3(59.9wt%)and SiO2(13.8wt%), the main phase was boemite and quartz phase, its average particle size was 10.39 ?m(D50=10.39 ?m), and its particle size distribution was also concentrated relatively, so the particle size of purple sand and bauxite were very close and their size distribution were consistent.(2)The sintering temperature of ceramisite proppant made by pure purple sand is 1170℃, its main phase was quartz and second phase is mullite, bulkdensity was 1.30g/cm3, apparent density was 2.464g/cm3, crushing ratio(35MPa closed pressure) was 13.32%. Therefore, the crushing ratio of proppant couldn’t meet the Chinese Oil and Gas Industry Standards SY/T5108-2014 requirements,that demand crushing ratio must less than 10%.(3)The crushing ratio of ceramisite proppant decreased with the addition of the bauxite increasing, when the addition of bauxite increased to 30wt%, and sintered in 1420℃, the crushing ratio(35MPa closed pressure) of ceramisite proppant was 8.12%, that meet the requirements of industry SY/T5108-2014 well.(4)Supposing that the firing temperature is constant, the increased of bauxite addition improved the Al/Si, and promoted the mullite and corundum phase generated. When the addition of bauxite increases to 20wt%, the corundum start to generate, and form composite ceramic material, the performance of proppant has been significantly improved.(5)When the addition of bauxite reached 30wt% and the sintering temperature was 1420℃, neither we had raised nor lowered the sintering temperature, the crushing ratio of ceramisite proppant would on the rise. A lower sintering temperature would bring a low activation energy, slow diffusion and inadequate reaction, so the proppant would have a low performance. If the sintering temperature turned to be high, the proppant would be over sintered,and its performance degradation with expanded molten.