The Effect of Quartz Content on the Mechanochemical Activation of Kaolinite

Pozzolanic activity of mechanochemically and thermally activated kaolins in cement

“…Limited grinding (1 h) resulted in a shift to lower temperature of the dehydroxylation peak without significant intensity decrease or peak broadening. The shift to lower temperature was larger for K_IR, from 530 to 495°C, than for K_CZ, from 520 to 505°C, indicating stronger structural alteration due to co-grinding with quartz [32]. The shift to lower temperature can be explained by the breakage of H-bonds between adjacent kaolinite layers during delamination [34].…”

“…The observed differences in rates of comminution can be related to differences in composition of the two kaolins [19]. Specifically, the quartz content in the K_IR composition may assist in the grinding process [32] and allow K_IR to reach the maximum BET value at 1 h of grinding.…”

Structure and pozzolanic activity of calcined coal gangue during the process of mechanical activation

“…3.2.1 XRD analysis XRD patterns of SD1, SD2 and SD4 are shown in Fig.5. It suggests that the major phases of gangue are metakaolin and α-quartz [6][7][8][9] .Compared with SD1, there are two changes for SD3 and SD4 samples. Firstly, from Fig.5(a), the peak intensity of (020) and (002) of metakaolin gradually reduces, and the peaks width gradually broadens, which shows the mineral lattice distortion happened and the lattice tends to amorphous with increaing of specific surface area of the gangue.…”

“…FT-IR spectra of SD1, SD3 and SD4 are shown in Fig.6, which maintains the characteristic absorption bands for metakaolin and α-quartz [6,[9][10][11] . From SD1 to SD4, with decreasing the grain size, absorption band 1083 cm .…”

Simultaneous removal of Pb2+, Cu2+, Zn2+ and Cd2+ from highly acidic solutions using mechanochemically synthesized montmorillonite–kaolinite/TiO2 composite

“…Fragmentation, distortion, breakage of crystalline network and particle size reduction followed by an increase of the surface area, exfoliation of particles and amorphization, can lead to the increase of the removal efficiencies of the pollutants (Makó et al, 2001;Hrachová et al, 2007;Vdović et al, 2010). On the other hand, longer milling times lead to the agglomeration of finer particles that result in the decrease of the cation exchange capacity (CEC) (Nenadović et al, 2009;Vdović et al, 2010).…”