Study on mechanochemical effect of silica for short grinding period

Pozzolanic activity and filler effect of sugar cane bagasse ash in Portland cement and lime mortars

“…7 shows, however, that the widening of peaks, which would be characteristic of amorphization, is not observed in the present study, even after the longest grinding time studied (240 min). This contrasts with results from Kitamura et al [22] from grinding of Al(OH) 3 and from Palaniandy et al [16] from oscillating grinding of silica that show evidence of amorphization at grinding times that are comparable to the ones used in the present study. It is important to note that an increase in compressive strength of mortars generated by vibratory grinding of the silica powder was observed by Benezet and Benhassaine [23].…”

“…The distinction between these two populations start to disappear at longer grinding times, as they tend to overlap. This appearance of poly-modal distributions has already been observed by Palaniandy et al [16] in vibratory grinding of silica and has been attributed to the tendency of fine particles to agglomerate.…”

Performance of Portland cement pastes containing nano-silica and different types of silica

“…This confirms the increase in hydration promoted by the ultrafine quartz since this sample caused a significant delay of the acceleration period. It is worth noting that amorphous compounds were not observed in the quantitative X-ray diffraction analyses by Rietveld method of both QZ1 and QZ2, indicating that ultrafine grinding did not promote amorphization of quartz as was previously reported in some studies [17,43]. X-ray diffraction scan of QZ2 is shown in Fig.…”

“…Grinding can also be responsible for promoting partial amorphization and significant increase in specific surface area [5][6][13][14][15][16][17][18]. Indeed, mechanical size reduction has been widely used to render chemical reactivity to inert silica-based materials, especially in the application of high-energy milling, which breaks the particles and generates fine, ultrafine and nanometer-sized particles [17,[19][20][21][22][23].…”

Impact of mechanochemical effect on chalcopyrite leaching

“…The ground particles normally exhibit lower peak intensity and broader base which indicates the measured phase has transform to partially amorphous phase. The discussion on impact of high intensity grinding that resulting mechanochemical effect has been reported in many publications (Achimovicov et al, 2006;Arbain et al, 2011;Balaz, 2000;Balaz, 2008;Balaz and Dutkova, 2009;Jamil and Palaniandy, 2011;Palaniandy et al, 2007;Palaniandy et al, 2008b;Welham, 2001a;Welham, 2001c).This phenomenon is more pronounced when the particles were ground to below 10 µm. There are industrial stirred mills that produce product size below 10 µm.…”