Research and Development of Deep Sea Mining Technology in China

Abstract

This paper discusses the state of the art of deep sea mining technology in China. The research and development of deep sea mining technology in China started from the polymetallic nodules mining. A pilot mining system, which consists of a self-propelled collector, hydraulic pipe lift and a surface vessel, has been developed. In 2001, a lake mining trial was conducted in the pilot system, through which artificial nodules lying on the floor of lake were collected by the collector and then transported up to the surface vessel by a flexible hose subsystem. The lake mining trial confirmed the maneuverability and controllability of the self-propelled collector, the efficiency of the hydraulic pick-up device, and the feasibility of lifting system with flexible hose. In addition, some research has been conducted on the cobalt-rich ferromanganese crusts mining techniques such as the methods of in situ fragmentation and separation of crusts from the substrate rock, and the technique of crust mining using the robotic seabed vehicles. During the past decade, China has enhanced the research on key techniques of deep sea mining system. Some new laboratories and facilities have been constructed, including a miner test laboratory with a 50 mx50 mx5 m basin, a lifting test setup which can carry out circular lifting test and one way transporting test, and a computer simulation research laboratory which can partially test some boundary conditions and demonstrate simulation results. China has further planned to investigate the techniques of deep sea mining for polymetallic sulphide, to develop the facilities for the application, and to assess the economic feasibility of the deep sea mining development. We will continue to explore the new deep sea mining methods and technologies.

Status and Prospects of the Development of Deep-Sea Polymetallic Nodule-Collecting Technology

“…In the experiment, the maximum operating water depth is 514 m, the collection capacity of polymetallic nodules is 10 t/h, the longest distance of a single drive is 2881 m, and the underwater positioning accuracy is 0.72 m, which realizes the ability of the predetermined path in the autonomous driving mode, and a pentagram with a unilateral length of 120 m emerges from the seafloor along a set path [43,44]. In 2021, under the organization of the China Oceanic Association, the Changsha Research Institute of Mining and Metallurgy, the Changsha Research Institute of Mines, Central South University, and other dozens of enterprises, research institutes, and universities jointly developed a 3500 m water depth, 1/10 commercial mining scale mining vehicle (as shown in Figure 8), and a more than 1000 m water depth test lifting pump and pipeline system ( which can be extended to 3500 m water depth ) [36,37]. In July of the same year, the joint test of the 1300 m water depth system was completed.…”

“…It is also the world's first mining linkage sea trial of tracked, self-propelled collectors and hydraulic pipeline-lifting. In 2021, under the organization of the China Oceanic Association, the Changsha Research Institute of Mining and Metallurgy, the Changsha Research Institute of Mines, Central South University, and other dozens of enterprises, research institutes, and universities jointly developed a 3500 m water depth, 1/10 commercial mining scale mining vehicle (as shown in Figure 8), and a more than 1000 m water depth test lifting pump and pipeline system ( which can be extended to 3500 m water depth ) [36,37]. In July of the same year, the joint test of the 1300 m water depth system was completed.…”

The Development History and Latest Progress of Deep-Sea Polymetallic Nodule Mining Technology

“…By integrating the above studies, a deep-sea nodule commercial mining system was essentially proposed. Figure 3 shows the system scheme suggested by COMRA [50]. In this system, the lifting pumps are multistage centrifugal pumps, and the nodule collector is self-propelled on the seabed using crawler tracks.…”

Study on Collection Performance of Hydraulic Polymetallic Nodule Collector Based on Solid–Liquid Two-Phase Flow Numerical Simulation

“…As a critical component of the miner, the front collector directly relates to the miner's working performance. The collection form of the front collector includes the mechanical type [10], the hydraulic type [11] and the compound mechanical-hydraulic type [5]. Currently, the hydraulic type collector has been widely applied due to its advantages of high efficiency, great environmental protection, and low cost [12].…”