Analysis for ferromanganese minerals of the Pacific Oceanic polymetallic nodules and the study for its origination

The ferromanganese minerals are important composition of the oceanic polymetallic nodules.To understand its variety, morphology, distributive characteristic and crystal degree in all types of nodules, not only help to the study on the origination of the manganese minerals and manganese nodules, but also has real significance to ore dressing and smelting as well as synthesis utilization of resources.Through complex analysis and apraisal by many methods such as TEM, we considered that the major fer-romanganese minerals of polymetallic nodules are todorokite, vernadite, birnessite, manganosite.jacobsite and needle ironstone etc.All of these minerals are of bad crystallinity.but todorokites' crystallinity is better than others'.In the rough nodules.todorokite's content is rich and little change from out-layer to core.The vernadite distributes in almost all of manganese nodules.but its crystal degree is bad.Ferri-minerals contents of the manganese nodules in east area are less than that in west area.and inside a single nodule it is higher in out-layer than that in core.Manganese minerals are distributed at columns and laminae of stromatolites in nodules, they are mostly looking like bunches, fibries and dendrites, just have the same shape with hypha morphology of ultra-microbes.The rough type manganese nodules are the targets for ore dressing.