Contribution of multivariate analysis to the correlation of some properties of kaolin with its mineralogical and chemical composition

Clay Minerals ◽  
1998 ◽  
Vol 33 (1) ◽  
pp. 65-75 ◽  
Author(s):  
E. Galan ◽  
P. Aparicio ◽  
I. Gonzalez ◽  
A. Miras

AbstractAccording to multivariate analysis, the following were established (a) kaolinite crystallinity index (KCI) values determined by XRD are highly correlated to one another and seemingly influenced by kaolin impurities; (b) kaolin minerals are concentrated mainly in the fractions <4 µm; (c) the kaolin surface area as determined by the BET (nitrogen adsorption) method is more markedly affected by kaolin impurities than by kaolin minerals themselves; (d) BET surfaces increase when kaolinite crystallinity decreases; (e) brightness is inversely correlated with kaolin impurities; (f) the more ordered the kaolinite and the greater the proportion in the <4 µm fraction of the kaolin, the greater the brightness; and (g) KCI values are particle size-distribution dependent for sedimentary-residual kaolins. The correlations obtained were better when kaolins were selected according to their origin because the kaolin minerals and their impurities, particle size-distribution and texture were more alike. The industrial properties of kaolin can not be predicted from other basic properties such as mineralogy, KCI, etc., because they are intricately related to one another.

2018 ◽  
Vol 156 ◽  
pp. 03046 ◽  
Author(s):  
Widyawanto Prastistho ◽  
Winarto Kurniawan ◽  
Hirofumi Hinode

The influences of mechanical milling on Indonesian Natural Bentonite (INB) characteristics and manganese (Mn) removal from acid mine drainage (AMD) were investigated. The INB characteristics were observed by scanning electron microscope (SEM), X-ray diffraction (XRD), nitrogen adsorption-desorption for specific surface area (SSA) and microporosity measurement, cation exchange capacity (CEC) and particle size distribution (PSD) analyzer. Four minutes milling with frequency 20 Hz on INB caused morphological change which showed more crumbled and destructed particle, lost the (001) peak but still retained the (100) peak that indicated delamination of montmorillonite mineral without breaking the tetrahedral-octahedral-tetrahedral (T-O-T) structure, rose the CEC from 28.49 meq/100g to 35.51 meq/100g, increase in the SSA from 60.63 m2/g to 104.88 m2/g, significant increase in microporosity which described in the t plots and decrease in the mean particle size distribution peak from 49.28 μm to 38.84 μm. The effect of contact time and effect of adsorbent dosage on Mn sorption was studied. Both unmilled and milled samples reached equilibrium at 24 hours and the pH rose from 4 to 7 in first 30 minutes. The Mn removal percentage increased significantly after milling. Using Langmuir isotherm, the maximum adsorbed metals (qmax) also increased from 0.570 to 4.219 mg/g.


2019 ◽  
Vol 2 (98) ◽  
pp. 81-84
Author(s):  
K. Szmajnta ◽  
M. Szindler

Purpose: The main purpose of this publication is to bring closer method of synthesis and examining basic properties of TiO2, ZnO and NiO nanoparticles (NPs), and investigate their possible biomedical application. Design/methodology/approach: Nanopowders were made with sol-gel method. Surface morphology studies of the obtained materials were made using Zeiss's Supra 35 scanning electron microscope and the structure using S/TEM TITAN 80-300 transmission electron microscope. In order to confirm the chemical composition of observed nanopowders, qualitative tests were performed by means of spectroscopy of scattered X -ray energy using the Energy Dispersive Spectrometer (EDS). The DLS (Dynamic Light Scattering) method was used to analyse the particle size distribution using the AntonPaar Litesizer 500 nanoparticle size analyser. Changes in particle size distribution at elevated temperatures were also observed. The TiO2, ZnO and NiO NPs with spherical shape were successfully produced by sol-gel method. Findings: The diameter of the as prepared nanoparticles does not exceed 25 nm which is confirmed by the TEM analysis. The highest proportion among the agglomerates of the nanoparticles has been shown to show those with a diameter of 80 to 125 nm. The qualitative analysis of EDS confirmed the chemical composition of the material. Practical implications: Nanoparticles (NPs) has been receiving an incrementally increasing interest within biomedical fields researchers. Nanoparticles properties (physical, chemical, mechanical, optical, electrical, magnetic, etc.) are different from the properties of their counterparts with a larger particle size. Originality/value: The nanoparticles were prepared using sol-gel method which allows the particle size to be controlled in a simple way.


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