Effect of solid/ball ratio and grinding time on the mechanical activation of kaolin

Abstract

Kaolin is one of the most important clay minerals that attracts attention due to its various application areas such as the ceramic industry. In this study, the effects of solid/ball ratio and grinding time on the mechanical activation of kaolin were investigated. Samples with 10 mu m particle size were activated in The Fritsch Pulverisette 5 Ball Mill (Two Chamber Mill) at 400 rpm at different solid/ball ratios (1/10, 1/20, 1/30) and at different times (0, 15, 30, 45, 60 min.). The Planetary Ball Mill had 2 pieces of 80 ml tungsten carbide jar. Fritsch Pulverisette 5 was used in mechanical activation experiments and the planetary ball mill that can grind with the effect of impact/collision force. The X-ray diffraction (XRD) analysis results showed significant decrease in the intensity of the peaks after activation. The Fourier Transform Infrared Spectroscopy (FTIR) analysis spectra of the ground samples showed transformation to amorphous kaolinite. The results of the Scanning Electron Microscopy (SEM) with EDX analysis (SEM-EDS) analysis showed that in the unactivated kaolin, micro-size particles agglomerated among the larger particles. In the results of the particle size analysis and the Brunauer-Emmett-Teller (BET) analysis, it was observed that the specific surface area of kaolin increased as the grinding time increased. In the Thermogravimetric Analysis and Differential Scanning Calorimetry (TGA-DSC) analysis results, it was observed that the mass loss in mechanically activated samples occurred at lower temperatures. All the analysis results were examined and it was determined that the grinding time was more effective than the solid/ball ratio. It was concluded that the mechanical activation process of kaolin was more successful under the conditions 1/30 solid/ball ratio and 45 min. grinding time.