(Table 11-I, page 338) Metal contents (%) of a representative sampling of manganese nodules from the North Pacific high-grade region

Two types of deep-sea dredges are currently under development for the mining of the manganese nodules, a deep-sea hydraulic dredge and a mechanical cable-bucket system. Both systems offer some advantages with the hydraulic system appearing to be advantageous in themining of a specific deposit for which it is designed while the cable-bucket system appears to be somewhat more flexible in working in a variety of deposits, topographic environments, and water depths. Environmental studies conducted in conjunction with deep-sea tests of the two types of mining systems currently indicate that substantially no environmental damage will be done in the mining of the deep-sea nodules. Because of the nature of the deposits and the way in which they can be mined, the manganese nodules appear to be a relatively pollution free and energy-saving source of a number of industrially important metals.

当前，针对锰结核（manganese nodules）的深海开采，已有两款专用采矿挖泥系统处于研发阶段，分别为深海液压式挖泥系统与机械缆斗式开采系统。两款系统各有优劣：液压式系统在其适配的专属矿床开采中优势显著，而缆斗式系统则可在多种矿床、地形环境与水深条件下灵活作业，适应性更强。目前，针对两款采矿系统开展的深海试验同步配套的环境研究表明，深海锰结核开采过程中基本不会造成实质性环境破坏。鉴于此类矿床的赋存特性与可行的开采工艺，锰结核堪称一种相对低污染且节能的工业重要金属供给源。