保温时间对添加废陶粒砂制备支撑剂结构和性能的影响

为了缓解高品位铝矾土资源日益匮乏的现状,同时降低支撑剂的生产成本,本研究以二级铝矾土和固废陶粒砂为主要原料,通过添加锰矿粉和白云石作为烧结助剂,最终经1260℃烧结制备得到刚玉-莫来石基陶粒支撑剂。在烧结过程中,讨论了保温时间对支撑剂物相结构和性能的影响。结果表明:随着保温时间的延长,支撑剂物相开始析出针状莫来石,而且晶粒尺寸逐渐变大,随之转变为棒状莫来石并与颗粒状的刚玉相互交叉分布于支撑剂内部,从而形成致密的交联结构。当保温时间为2 h时,支撑剂的性能最佳:体积密度为1. 65 g/cm^3,52 MPa闭合压力下的破碎率达到8. 5%,符合石油天然气行业标准要求,说明固废陶粒砂可以被循环利用制备支撑剂。

Effects of Holding Time on Structure and the Properties of Proppants Synthesized by Adding Waste Ceramic Sands

In order to alleviate the shortage of high-grade bauxite resources and reduce the production cost of proppant, the corundum-mullite ceramic proppants were prepared using the second-rate bauxite as the main raw material by adding solid waste ceramic sands, while the manganese powder and dolomite are also used as the additives when the sintering temperature was 1260 ℃. In the sintering process, the effect of holding time on the structure and properties of proppants were systematically investigated. The result show that with the increasing of holding time, the needle-shaped mullite started to be formed. Meanwhile, it was turned from acicular to columnar with an increasing size. Finally, the crossing of the rod-shaped mullite and granular corundum were distributed in the ceramic proppants, which formed the compact cross-linked structure. When the holding time was kept 2 h, the proppants show outstanding mechanical properties with the breakage ratio of 8.5% under 52 MPa closure pressure and the bulk density of 1.65 g/cm 3, which accorded well with the requirements of petroleum and natural gas industry standards. Therefore, the above analysis shows that the solid waste ceramic sands can be recycled effectively to prepare proppants.