Nautilus edges closer to production

THE world’s first deep-sea copper/gold project is edging closer to production in the Bismarck Sea off Papua New Guinea, promising to create a new industry to benefit the people of New Ireland, East New Britain and PNG.
After several years of careful research, planning and preparation, Nautilus Minerals Inc, the company developing the Solwara 1 project, aims to commence production in the last quarter of 2013.
Nautilus had started construction of three sophisticated remote-controlled machines that will be used on the seafloor, at depths of about 1,600m, to mine ultra-high grade deposits of gold and copper at Solwara 1.
The mined material will be pumped as slurry to a ship above and then transported to treatment facilities, probably elsewhere in Asia.
Solwara 1 had a total resource of about 2.1 million tonnes, which was a modest number compared with many land based mines.
However, the material is high grade, running at an average of about 7% copper, which is more than 10 times richer than typical land based copper mines.
The gold grade is also high, averaging about 7g/t, which is more than three times the grade of many land based mines.
Besides the high grade of minerals found at Solwara 1, the project was 30km offshore from Rabaul and far away from residential communities.
It will create employment and business opportunities for the region, and its impact on the environment will be minimal, and carefully managed.
Nautilus aimed to produce around 1.3 million tonnes of ore per year, and the initial size of the area affected by the operations is small, at only 0.11sqkm.
The company will not be creating a large pit as typically seen at most land-based mines, which are shifting more than 50 million tonnes of material per year, and often cover more than 10-20sqkm.
The Solwara 1 deposit sit virtually exposed on the seafloor, having been formed by the precipitation of minerals from superheated hydrothermal fluids which gush up from deep within the earth, through cracks and fissures in the seafloor.
These types of deposits tend to be relatively small, forming in mounds on the seafloor which can be broken up and collected by the seafloor mining machines without any use of blasting or explosives.
Because the material sits close to the surface of the seafloor, there is virtually no waste material created.
And as there was no processing of the ore at the mine site, there are no tailings released into the Bismarck Sea.
Nautilus had extensive exploration programmes aimed at identifying further deposits in the Bismarck Sea and elsewhere in the Western Pacific, including in Tonga.
The company had already identified many potential deposits and numerous hydrothermal fields, but  the full extent of these has not yet been quantified.
There are estimated to be potentially thousands of these hydrothermal vent sites on the bottom of the oceans around the world but many of them will be too small to develop.
Nautilus had been granted all the necessary permits by the PNG government to begin production at Solwara 1.
In March of this year, the government decided to take a 30% stake in the project, ensuring that the people of Papua New Guinea participated in the economic benefits of this landmark project.
The government’s pioneering decision ushers in a new frontier as countries around the globe look to the ocean for mineral resource development.
Nautilus had relied heavily on proven deepwater technologies in the design of its production system.
It  comprised three main
components: the seafloor production tools, the riser and lifting system and the production support vessel. Using remotely operated seafloor production tools, ore is broken and then gathered by a large robotic machine.
The Auxiliary Cutter (AC) was a preparatory machine that deals with rough terrain and creates benches for the other machines to work.
The second machine, the Bulk Cutter (BC), has higher cutting capacity to work benches created by the AC.
Both machines leave cut material on the seafloor for the Collecting Machine (CM) which will collect the material by drawing it in as seawater slurry and transferring it to the “riser and lifting system” (RALS).