Instrumental Characterization of Pretoria Clay Soil by XRF, XRD and SEM

Abstract

The products of refractory materials are used for lining furnace, incinerators and kilns among other uses and they have the potential of withstanding high temperature without deformation. The objective of the research was to characterize the clay soil sample collected from Tshwane University of Technology in Pretoria. The sample, collected from a location Latitude 25.0969˚S and Longitude 28.1624˚E, was oven-dried, pulverized and sieved in the laboratory. Mineralogical and elemental compositions of the sample were determined by using X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF) and Scanning Electron Microscopy (SEM) analytical methods. The XRF analysis revealed Fe 2 O 3 , Al 2 O 3 and SiO 2 as the major constituents, while the other elements occur in minor quantities. Mineralogically, the three samples contain Montmorillonite, Kaolinite and Bentonite, while Samples A contained Quartz in addition to earlier mentioned minerals, samples B and C contained Albite.

The use of basalt scoria as a geopolymer cement to increase soil bearing capacity

“…The results of the characterization of the oxide content of clay and basalt can be seen in Table 2. The results of this soil XRF are the same as those from Nigeria (Olaseinde et al, 2020). It is revealed that SiO2, Fe2O3, and Al2O3 are the main constituents in the soil.…”

The Kaolinite Crystallinity and Influence Factors of Coal-Measure Kaolinite Rock from Datong Coalfield, China

“…(2) ordered: HI = 1.1-1.3; (3) relatively disordered: HI = 0.8-1.1; (4) disordered: HI < 0.8. Additionally, in the X-ray diffraction pattern, with the decrease in crystallinity, the sharpness and intensity of the (001) and (002) basal surface reflection peaks decrease [35,36]. The HI result indicates that the kaolinite crystallinity in C3R, C2F and S4F kaolinite rocks was ordered, the crystallinity of C5F1 and C5G was slightly disordered, and it was disordered in C5F2 and C8F.…”

“…X-ray diffraction analysis is one of the most extensive and important clay mineral research methods, and it can be used to study the types and forms of kaolinite structural defects, complex interlaminar interaction, polytype identification and clay mixtures through quantitative or semi-quantitative analysis. X-ray diffraction can be used to study mineral crystallinity and obtain the chemical composition information of major clay mineral components in samples [35,36]. Here, XRD data were used to calculate the Hinkley index (HI) of kaolinite to judge its relative crystallinity (Table 1).…”

“…When using a Hinkley index analysis, comparisons can only be made if the experimental data are under the same experimental conditions. In addition, the HI index is more suitable for studying kaolinite, which is from clay deposits, but it has some limitations when there are multiple minerals in the samples due to many factors affecting the structural defects of kaolinite, such as the stacking of layers, ion space, grain size, crimping of crystal layers and the influence of experimental conditions [35,36].…”