Abstract:

This is a mini-review paper about microscopic characteristics of manganates in ferromanganese nodules. The manganates in diagenetic nodules are mainly todorokite, buserite and birnessite. The manganates in hydrogenetic nodules are mainly vernadite.The crystal structure of todorokite is tunnel structure. The crystal structure of buserite, birnessite and vernadite is layered structure. Both transition metals (Co, Ni, Cu, V, Mo, W, and Pt) and rare earth elements (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y and Sc) are enriched in manganates. Mechanisms for enrichment of transition metals are the specialistic adsorption and the selective adsorption. Currently, it is generally believed that rare earth elements are adsorbed by manganates through electrostatic attraction.