Physicochemical characterization by AXRF and XRD analysis of clays samples from Bulungu, Kwilu Province, Democratic Republic of Congo.

This study analysed four clay samples from Bulungu, Kwilu Province, DRC, using X-ray fluorescence (XRF), X-ray diffraction (XRD) and thermo gravimetric analysis (TGA). The results show that these clays are made up of oxides regarding their decreasing proportions: silica (over 50%), alumina (20%), iron oxide (10%) and potassium oxide (over 5%). Mineralogically, they mainly contain illite (over than 50%), kaolinite (19%), albite (5%) and microcline (10%), with a low percentage of quartz (less than 3%) which makes them suitable for use in cement industrys. Trace element analysis reveals the presence of Rb>Zn>Cr>Ni>Cu>Th>U in decreasing proportions. Thermo gravimetric analysis shows a weight loss of around 18% at 800°C.