Changes in distribution and microstructure of bauxite residue aggregates following amendments addition
Changes in distribution and microstructure of bauxite residue aggregates following amendments addition
复制标题
添加修正后铝土矿残渣聚集体分布和微观结构的变化
DOI：
10.1016/j.jes.2018.10.010
复制
发表时间：
2019
影响因子：
6.9
通讯作者：
William Hartley
中科院分区：
文献类型：
--
作者：
Shengguo Xue;Yuzhen Ye;Feng Zhu;Qiongli Wang;Jun Jiang;William Hartley
溴化铵残渣是一种高碱性副产品，通常被丢弃在残渣处理区。改善土壤形成过程，对特殊退化土地进行重新植被，是炼油工业可持续管理的一项有前途的战略。通过室内培养试验，研究了石膏和蚯蚓粪对铝土矿废渣稳定集料形成的影响。集料粒度分布的分形理论进行了量化，而残留物的微观结构，通过扫描电子显微镜和同步辐射为基础的X射线显微计算机断层扫描。改性剂的加入增加了铝土矿残渣中大团聚体（> 250 μm）的含量，提高了团聚体的稳定性。石膏和蚯蚓粪添加后，分形维数从2.84下降到2.77，这表明骨料颗粒分布更均匀。从扫描电子显微镜和三维显微结构的图像表明，修正案刺激形成的残余物聚集体的结构改善。孔隙参数，包括孔隙度，孔喉表面积，路径长度和路径曲折度增加修正添加。结果表明，添加石膏和蚯蚓粪有利于改善铝土矿废渣的物理状态，提高铝土矿废渣的易生性。
Bauxite residue is a highly alkaline byproduct which is routinely discarded at residue disposal areas. Improving soil formation process to revegetate the special degraded lands is a promising strategy for sustainable management of the refining industry. A laboratory incubation experiment was used to evaluate the effects of gypsum and vermicompost on stable aggregate formation of bauxite residue. Aggregate size distribution was quantified by fractal theory, whilst residue microstructure was determined by scanning electron microscopy and synchrotron-based X-ray micro-computed tomography. Amendments addition increased the content of macro-aggregates (> 250 μm) and enhanced aggregate stability of bauxite residue. Following gypsum and vermicompost addition, fractal dimension decreased from 2.84 to 2.77, which indicated a more homogeneous distribution of aggregate particles. Images from scanning electron microscopy and three-dimensional microstructure demonstrated that amendments stimulate the formation of improved structure in residue aggregates. Pore parameters including porosity, pore throat surface area, path length, and path tortuosity increased under amendment additions. Changes in aggregate size distribution and microstructure of bauxite residue indicated that additions of gypsum and vermicompost were beneficial to physical condition of bauxite residue which may enhance the ease of vegetation.