Abstract:In this study, manganese cutans were synthesized on the surface of quartz sand particles. Crystal structure characteristics of the minerals in the cutans were investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of mole ratio R of Mn2+:Mn7+ (1:1, 1:2, 1:3 and 1:4 respectively), synthetic temperature (30, 50, 70, 90 and 110℃ respectively), standing and churning time (48, 72 and 96 h respectively), and quartz sand amount (5, 10, 20, 30 and 40 g respectively) on the formation of manganese oxides in the cutans were discussed. The obtained results showed that, with the decrease of R (Mn2+:Mn7+), the minerals in the manganese cutans were transformed from cryptomelane to birnessite. Moreover, the crystallinity of minerals increased, the manganese content decreased, and the granular structure increased. With the rising of synthesis temperature, the crystallinity of the mineral in the cutans increased, and the manganese content in the cutans decreased, but there was no variation of the type of the mineral. The churning did not affect the mineral type of the cutans, but the longer the stirring time, the higher the mineral content in the cutans. As the quartz added amount increased, the crystallization of the minerals was declined, and the mineral content on the surface of the cutans was reduced first and then rose when the content of quartz sand was 10 g, but the mineral type did not change.