Polymetallic nodules (hereinafter referred to as nodules) were called manganese nodules in many literatures in the past.

It is a polymetallic mineral resource distributed on the ocean seabed.

Nodules generally consist of a core and a shell surrounding it.

The shell material is formed by the alternate growth of manganese phase minerals, iron phase mineral microlayers and clay mineral microlayers.

The shell is rich in useful metal components such as Mn, Cu, Ni, Co, and Mo, Pb, V, and Ti.

In 1873, the British research ship Challenger discovered polymetallic nodules for the first time in the Atlantic Ocean.

However, due to limitations of testing and offshore survey technology, the composition of nodules and their resource value have not been recognized for a long time.

In the middle of this century, the rapid development of industrial technology and the application of high and new technologies provided technologies and means for the investigation, research and development of oceanic nodules.

In the mid-1960s, American scientist J.L. Mero estimated that the Pacific nodule reserves were approximately 170×104Mt, and pointed out that they had huge economic prospects.

At the same time, the nodules are still growing and their reserves are still increasing. Some people estimate that their growth rate is 6 to 10Mt/a.

Therefore, nodule resources are an “inexhaustible” mineral resource.

The publication of these research results has gradually recognized the potential importance of deep seabed minerals, and deep seabed mineral resources are mainly useful metal elements such as Cu, Co, and Ni that people are interested in.

Therefore, many countries have conducted surveys and studies on Pacific nodule resources.

In the 1970s, research on nodule investigation, exploration and development in the Pacific reached a climax.

Existing geological-geophysical surveys believe that the area between the Clarion and Kripparton fault zones (referred to as the CC area) is the best nodule-rich zone in the Pacific Ocean.

Therefore, the surveys and exploration activities of most countries and consortiums are concentrated in this area.

The tuberculosis exploration situation in several countries is briefly described below.

1.1.1 The United States The United States is the earliest and largest country to carry out nodule survey and exploration. Moreover, four multinational companies in the country have occupied the most favorable blocks in the nodule-rich zone of the CC area.

The characteristics of polymetallic nodule investigation work in the United States are: (1) In large-scale investigations and studies on nodules, participating units include government agencies, research institutes and universities, as well as large companies and enterprises.

Including the Geological Survey, the National Oceanic and Atmospheric Administration, Scripps Institution of Oceanography, the Lamont-Doherty Institute of Geology, and dozens of universities; since 1962, the Marine Minerals Corporation (DMCO), Ocean Management

Company (OMI), Ocean Mining Associates (OMA) and Kennecott Consortium (KCON) are engaged in nodule survey, exploration and mining tests.

(2) The Marine Mineral Resources Office was established in the National Oceanic and Atmospheric Administration to be responsible for planning, coordinating, and implementing the development of marine minerals.

Before the adoption of the United Nations Convention on the Law of the Sea, the U.S. government declared the Deep Seabed Mineral Development Act to take effect in 1980 and approved four U.S. companies to apply for exploration rights and development rights in nodule mining areas.

(3) Funded by the government and science funds, implement a series of investigation and research plans, including investigation and research on the causes of nodules, material composition and metal content, distribution patterns, deep-sea mining environment and topography, sediment types, etc.

(4) Four multinational companies, mainly American companies, focus on nodule mineral resource investigation, exploration, and deep-sea mining experiments.

In terms of nodule exploration, in addition to using conventional marine geological samplers to collect mineral samples and seismic and magnetic measurements for geophysical exploration, advanced instruments such as high speed exploration systems (HSES) and deep tow survey systems are also used.

equipment.

(5) The investigation and exploration of deep-sea nodules in the United States was basically ended in the late 1970s, and was turned to the investigation of other mineral resources.

1.1.2 Japan Japan is a country with poor mineral resources, and the government encourages the investigation, exploration and development of deep-sea nodule resources.

Nodule investigation and research in Japan began in the 1960s. Government agencies implemented a series of exploration plans, such as "Investigation and Research on the Basics of Deep-Sea Mineral Resources Development", "Basic Research on Deep-Sea Mineral Resources Exploration", "Research on the Development of Deep-Sea Mineral Resources" and "

"Geological Research on Deep Sea Mineral Resources", etc., and at the same time, the development of deep sea mining system and the mining test of "continuous chain bucket mining" system are carried out.

In 1974, Japan established the Deep Sea Mineral Resources Development Association, and in 1982 established the Manganese Nodule Mining System Research Institute, which is responsible for researching mining systems and investigating and selecting nodule mining areas.

Japan's method of conducting nodule surveys is the "asymptotic exploration method", which increasingly improves the accuracy of the survey as exploration and measurement progress.

The exploration stage can be divided into three major stages: general survey stage I, general survey stage II and general survey stage III (detailed exploration).

1. Overview Phase I The investigation task in this phase is to study the occurrence of tuberculosis.

This stage can be divided into 3 small stages.

Figure 1-1 Phase I2 project distribution map Figures 1-1 to 1-4 are all quoted from Svimitomo Corporation, 1988 (1) Overview Phase I1. The main task of this phase is to collect information and prepare various drawings, and pre-select possible

Tuberculosis survey area, prepare marine survey design report.