Characterization of two different sources of kaolin and local kaolin modification

Abstract

Kaolin imported from China and local kaolin with difference sieving process which is local kaolin A (bulk sample), local kaolin B (65 μm kaolin) and local kaolin C (45 μm kaolin) were characterized in this present research. Local kaolin B and local kaolin C were sieved using 65 μm sieve and 45 μm sieve respectively in wet condition. Then they were dried at 100 ºC for a hold day at heating rate 10º/min. The elemental analysis was investigated using X-ray Fluorescence, XRF. It was confirmed that bulk sample has higher amount of the main element which SiO2 and Al2O3 than kaolin imported from China which is 57% for SiO2 and 42.07% for Al2O3. Differential thermal and thermogravimetric analysis, DTA/TG shows thermal behavior for the kaolin sample. All kaolin samples occurred two stages which is exothermic reaction at the beginning of 200 ºC while endothermic reaction occurs around 500 ºC and all samples demonstrates mass loss by TG analysis. Morphological characteristic was investigated using Scanning electron microcopy, SEM and demonstrates bulk sample had been bigger size than the other sample. Particle size for all samples was investigated using Particle Size Distribution, PSA. PSA demonstrates that bulk sample has higher diameter amongst local kaolin which 14.607 μm for highest diameter. Phase transformation, phase content and crystal structure of kaolin imported from China and all local kaolin undergoes X-ray Diffraction (XRD). Kaolin imported from China demonstrated three phases (anorthic, monoclinic and orthorhombic) were obtained by using X-Pert High Score Plus software and undergo refinement by Rietveld method. In addition, bulk sample demonstrated the lowest mass loss by Thermogravimetric analysis (TGA). Finally, Scanning Electron microscope, SEM observed agglomerate particle for kaolin imported from China.