Nickel and copper accumplation as essential elements in 10-Å manganite of deep-sea manganese nodules

Abstract

MANY ferromanganese minerals have been found in marine manganese deposits. There have been terminological and intrinsic problems in accurately defining the constituents of manganese nodules(1), but 10-A manganite and delta-MnO(2) which are often compared with todorokite and birnessite seem to be the only major constituents of marine manganese nodules and crusts. [Note that birnessite is a natural species of delta-MnO(2) of four-line form, whereas marine delta-MnO(2) is two-line form, so marine and terrestrial delta-MnO(2) should not be compared directly with each other.] However, there have been few experimental studies of the mechanism of accumulation and the crystallochemistry of these elements in 10-A manganite of manganese nodules, although many experimental studies of adsorption of metals to natural and synthetic manganese and iron oxides have been made(7,8). I have now investigated the mechanism of accumulation of nickel and copper in manganese nodules by synthesising 10-A manganite and comparing the composition with that shown by microscopic and electron microprobe analyses of marine 10-A manganite.