(Table 3, page 8) Chemical composition and physical cahracteristics of manganese nodules from the Pacific Ocean

This paper reviews the state of the art in processing and extraction of ocean floor manganese nodules. It briefly reviews the mining sites where the abundant rich nodules occur and also discusses the metal distribution in nodules in view of economical processing and extraction of these metal values. The paper discloses in a detailed manner the physical and chemical characteristics of nodules, including porosity, surface area, water content and the effect of temperature on crystal structure of major constituents of nodules. In the extraction aspect of nodules, the paper reviews two different extraction schemes revealed in the literature, namely hydrometallurgical treatment and pyrometallurgical treatment. The hydrometallurgical treatments include acid leaching, ammonia leaching, leaching with reducing agents and leaching after high temperature pre-treatments such as in sulfating rousting, while the pyrometallurgical processes include smelting, chlorination-vaporization and segregation. The paper also covers metal recovery processes from leach liquor. An economic survey of processing nodules has been made in terms of problems associated with metal-marketing, and impact of metal production from nodules on mineral industries.本文综述了海底锰结核处理与提取领域的前沿研究现状。本文简要概述了富锰结核广泛赋存的矿区分布，并结合金属有价组分的经济化处理与提取需求，探讨了锰结核内部的金属分布特征。本文还详细阐明了锰结核的物理化学特性，包括孔隙率、比表面积、含水率，以及温度对结核主要组分晶体结构的影响。在锰结核提取方面，本文综述了文献报道的两类提取工艺，即湿法冶金处理（hydrometallurgical treatment）与火法冶金处理（pyrometallurgical treatment）。其中湿法冶金处理涵盖酸浸、氨浸、还原剂浸出，以及硫酸化焙烧等高温预处理后的浸出工艺；火法冶金工艺则包括熔炼、氯化汽化与偏析法。本文还涉及了从浸出液中回收金属的相关工艺。此外，本文针对锰结核处理开展了经济性调研，涵盖金属市场销售相关的各类问题，以及利用锰结核生产金属对矿物工业的影响。