太平洋多金属结核中铁锰矿物分析及成因研究

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

铁锰矿物是大详多金属结核的重要组成，了解不同类型结核中主要铁锰矿物种类、形态、分布特点和结晶程度等，不仅有助于对锰矿物乃至多金属结核成因的研究，而且对选矿冶炼和资源的综合利用也具有现实意义．本文通过透射电子显微镜等多种手段综合分析与鉴定，指出多金属结核中主要铁锰矿物有钙锰矿、水羟锰矿、水钠锰矿、方锰矿、锰铁矿和针铁矿等．结晶程度普遍较差，钙锰矿结晶相对好于其他矿物，并在粗糙型结核中含量高，外层至核心含量稳定，变化小．水羟锰矿广为分布，但结晶差．铁矿物含量东区低于西区，结核外壳铁含量高于内核．锰矿物分布在叠层石柱体和纹层内，呈束状、纤维状和树枝状，与建造多金属结核的超微生物菌丝体形态一致．粗糙型结核是选冶的主要对象．

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 originationof the manganese minerals and manganese nodules, but also has real signihcance to ore dressing and smelting as well as synthesisutilization of resources. Through complex analysis and apraisal by many methods such as TEM, we considered that the major ferromanganese minerals of polymetallic nodules are todorokite, vernadite, birnessite, manganosite, jacobsite and needle ironstoneetc. 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 lamiae of stromatolites in nodules, they are mostly looking like bunches, fibries and dendrites, just have the same shape with hypha morphologyof ultra-microbes. The rough type manganese nodules are the targets for ore dreSSing.