白云石对焦宝石陶粒晶粒发育及性能的影响

以陶粒的新原料-焦宝石为主要原料,白云石为熔剂性辅料利用陶瓷烧结工艺成功制备了粒径425~850 μm满足35 MPa闭合压力下使用的支撑剂.重点研究了助熔剂白云石的不同添加量对焦宝石陶粒支撑剂晶粒发育及性能的影响.利用SEM和XRD分别对含有不同添加量的白云石的陶粒支撑剂进行了显微形貌和物相结构的分析,并多次测试了陶粒支撑剂的体密、视密和破碎率,结果揭示了白云石的添加有助于促进棒状莫来石晶粒的发育,同时在保证破碎率低于9%的前提下具有降低陶粒支撑剂体密/视密的作用.     

Effect of different dopants on the long lasting phosphorescence behavior of CaTiO_3：Pr~（3＋）

In order to improve the luminescence properties of CaTiO3:Pr3+, a series of CaTiO3:Pr3+, such as CaTi0.97Nb0.03O3:Pr3+, Ca0.8Zn0.2TiO3: Pr3+, Ca0.8Zn0.2Ti0.97Nb0.03O3:Pr3+ and B3+-doped Ca0.8Zn0.2Ti0.97Nb0.03O3: Pr3+ were prepared through conventional solid state reaction method. The results of the photoluminescence excitation and emission spectra showed that all the samples emitted red phosphorescence at 612 nm originating from 1D2 to 3H4 emission of Pr3+ under the 337 nm excitation. When examined by the X-ray diffraction (XRD), all the samples presented a predominant phase of CaTiO3 (JCPDS# 42-423) except Zn2+-doped samples which also revealed another phase of Zn2Ti3O8 (JCPDS# 73-579). The results of the afterglow decay curves showed that co-doping Zn2+ ions, Nb5+ ions or adding a small amount of B3+ into Ca0.8Zn0.2Ti0.97Nb0.03O3:Pr3+ were effective in improving the photoluminescence properties of CaTiO3:Pr3+ phosphor. Thermoluminescence results showed that the trap existing in all the samples was the same as in CaTiO3:Pr3+ and doping singly Nb5+ or Zn2+ hardly changed the trap depth but co-doping Nb5+ and Zn2+ could modify the trapping level from 0.63 to 1.26 eV distinctively. In addition, adding a certain amount of B3+ into CTO-PZN could also deepen the trap depth.     

基于煤层气井用陶粒支撑剂的制备

以煤矸石和铝矾土为主要原料,采用50∶50和60∶40质量配比,再添加2wt％长石添加剂,在不同温度烧结制备了煤层气井用的20/40目经济型陶粒支撑剂.通过X射线衍射(XRD)和扫描电子显微镜(SEM)对陶粒的物相组成和显微形貌进行表征.实验结果表明:所制备的陶粒的视密度均低于3.0 g,/cm3,体积密度低于1.5 g/cm3,属于低密度范畴;当煤矸石与铝矾土配比为50∶50时,烧结温度在1400 ～ 1500℃制备的支撑剂,在35 MPa闭合压力下的破碎率均低于9％的行业标准(SY/T 5108-2014).     

Enhancement of luminescence and afterglow in Ca0.8Zn0.2TiO3:Pr3+ by Nb5+ substitution for Ti4+

Nb5+ doped Ca0.8Zn0.2TiO3:Pr3+ red long afterglow phosphors were synthesized by solid-state reaction methods. X-ray diffraction, photoluminescence spectroscopy and thermally stimulated spectrometry were used to investigate the effects of Nb5+ content on the crystal characteristics and luminescent properties of Ca0.8Zn0.2Ti1-xNbxO3:Pr3+ phosphors. The results showed that the addition of a small quantity of Nb5+ had negligible effect on the crystal characteristics of Ca0.8Zn0.2Ti1-xNbxO3:Pr3+, but it could change the trapping parameters (the depth of trap, frequency factors and the concentration of trapped charges at t=0) of Ca0.8Zn0.2Ti1-xNbxO3:Pr3+ phosphors, and then led to the enhance-ment of red fluorescence and phosphorescence at 612 nm originating from 1D2→3H4 transition of Pr3+. Both of the red fluorescence intensity and afterglow time reached the largest values in the sample of Ca0.8Zn0.2Ti1-xNbxO3:Pr3+ with x=0.05. The afterglow time of Ca0.8Zn0.2Ti0.95Nb0.05O3:Pr3+ phosphors lasted for over 24 min (≥1 mcd/m2) when the excited source was cut off.     

煤矸石掺量对陶粒支撑剂性能的影响

以铝矾土和煤矸石为主要原料,通过调整二者质量比(1:1,2:3和3:7),经造粒成球、不同温度烧结制备得到陶粒支撑剂。结果表明:当煤矸石掺入量为60%(质量分数)、35 MPa闭合压力下,满足破碎率行业标准的烧结温度范围为1 250～1 450℃,在该温度区间内,随着烧结温度的升高,样品的结晶相转变为棒状莫来石相,形成一种致密的网状交联结构,进而提高了陶粒支撑剂的抗破碎能力;当烧结温度为1 450℃时,体积密度及视密度分别为1.49和2.76 g/cm~3,破碎率指标达到最低值3.0%,证实利用煤矸石替代铝矾土可以制备出用于煤层气井开采用的陶粒支撑剂。