煤矸石中富含高岭土资源,为解决目前煤矸石中高岭土资源纳米级制备工艺存在的工艺烦琐、成本过高、产出率低等问题,采用超重力法制备纳米级煤矸石煅烧高岭土,通过单因素实验探究了旋转床转速(A)、反应时间(B)、物料流量(C)对煅烧高岭土粒径分布的影响,在此基础上以煅烧高岭土的D90为指标,采用响应面法进一步优化了制备参数。结果表明:超重力法制备纳米级煅烧高岭土的的回归方程为:Y=90.60−48.50A+17.62B+3.87C−11.50AB−3.50AC+25.25BC+25.33A2+29.58B2+28.58C2。方差分析结果表明二次项A2,B2,C2的P值均小于0.0001,说明其对高岭土平均粒径影响极显著。影响煅烧高岭土D90的三个因素按影响程度由高到低排序为A,B,C;影响煅烧高岭土D90的各个交互项按影响程度由高到低排序为BC,AB,AC。最佳工艺参数为:旋转床转速为1900r/min,反应时间为16min,物料流量为1600mL/min,在此条件下得到的煅烧高岭土(N-K)的D90为78nm;由扫描电子显微镜、透射电子显微镜分析可知最优条件下制得的煅烧高岭土呈现分散状态且片层厚度范围为2nm~8nm,符合二维纳米材料所具有的特征。

Coal gangue is rich in kaolinite resources.  To address the challenges in the  nanoscale preparation processes of kaolinite from coal gangue, including complex procedures, high  costs, and low yield, this study employed the supergravity method to prepare nanoscale calcined  kaolinite from coal gangue.  The effects of rotational speed (A), reaction time (B), and material flow  (C) on the particle size distribution of the calcined kaolinite were investigated through single-factor  experiments.  Based on these experiments, the response surface methodology (RSM) was used to fur‐ ther optimize the preparation parameters, with the D  of calcined kaolinite as the response indicator.   The results indicate that the regression equation for the preparation of nanoscale calcined kaolinite via  the supergravity method is Y=90. 60 −48. 50A+17. 62B+3. 87C −11. 50AB −3. 50AC+ 25. 25BC+25. 33A² +29. 58B² +28. 58C².  Analysis of variance shows that the quadratic terms A²,  B², and C² have P-values less than 0. 000 1, indicating that these factors significantly influence the  average particle size of kaolinite.  The factors affecting the D  of calcined kaolinite are in the order  from large to small: A, B, C, with the interaction terms affecting D  in the order from large to  small: BC, AB, AC.  The optimal process parameters are determined to be a ratational speed of  1 900 r/min, a reaction time of 16 min, and a material flow of 1 600 mL/min.  Under these condi‐ tions, the D  of calcined kaolinite (N-K) is found to be 78 nm.  Scanning electron microscopy (SEM)  and transmission electron microscopy (TEM) analyses reveal that the calcined kaolinite prepared  under optimal conditions exhibits a dispersed state with layer thicknesses within 2 nm−8 nm, charac‐ teristic of two-dimensional nanomaterials.