Reporters learned from the Ministry of Natural Resources that on 26 September 2018, two projects commissioned by the China Ocean Mineral Resources Research and Development Association (COMRA), which comes under the Ministry of Natural Resources, passed expert acceptance review: “development of a polymetallic nodule collector system oriented toward sea trials and integrated shallow-sea testing” and “500-metre-class sea trial of the polymetallic nodule collector system”.
As important components of the Jiaolong Tanhai (Jiaolong Explores the Sea) programme, the two projects were led by the Changsha Research Institute of Mining and Metallurgy of China Minmetals and completed jointly with the Changsha Institute of Mining Research, Central South University, Xiangtan University, Zhejiang University and other units, with support and logistics provided by enterprises and research institutions including Taihe Ocean Technology Group and Harbin Engineering University.
The Kunlong 500 seabed collector vehicle developed under the projects achieved breakthroughs in a number of key technologies, including driving on very soft seabed sediments, hydraulic collection of seabed minerals, and integrated seabed navigation and positioning. It completed test tasks including driving along planned paths on the seabed and terrain-adaptive nodule collection, and it carries independent intellectual property rights.
The sea trial ran from 1 May to 18 June, lasting 49 days, and was carried aboard the trial vessels Changhe Haiyang (Changhe Ocean) and Zhang Jian. Proceeding on the principle of moving from shallow water to deep, the sea trial team overcame the effects of complex sea conditions and completed the planned trial tasks safely and smoothly.
During the sea trial the Kunlong 500 seabed collector vehicle made 11 dives in total, of which 6 were in the 70-metre shallow-sea trial and 5 in the 500-metre sea trial. The maximum operating depth reached during the trial was 514 metres, with a polymetallic nodule collection capacity of 10 tonnes per hour, a longest single traverse of 2,881 metres and an underwater positioning accuracy of 0.72 metres. The vehicle demonstrated the ability to carry out seabed collection operations along preset paths in autonomous driving mode, and traced out a “China star” with sides 120 metres long in the designated area of the South China Sea.
This was China’s first trial of a seabed polymetallic nodule collector system at the 500-metre water depth class. The success of the sea trial marks the transition of China’s deep-sea mining system development from land-based testing fully into sea trials, and lays the foundation for the 1,000-metre-class integrated whole-system trial of China’s deep-sea polymetallic nodule mining test project.
