50,000 leagues under the sea: Deep sea mining and the world of tomorrow
71 percent of the Earth’s surface is covered in water, with the deepest known point in the oceans at 10,994 meters. With 96 percent of Earth’s water taken from the sea, what else can the ocean offer? is it time for us to take our mining operations under the sea? The CEO of Nautilus Minerals tells us what the future holds for terrestrial and deep sea mining.
“By 2040, our worldwide need for copper will have almost doubled,” says Mike Johnston, Helmsman, President and CEO of Nautilus Minerals, a deep sea mining company operating from Brisbane, Australia.
“There are still huge reserves under the sea. By 2040, I’d expect about 30% of copper to come from below the water. There’s huge potential.”
Nautilus, set up in 1997 and listed on the Toronto stock exchange in May 2006, specialises in mining metals at a depth of 1000 to 7000 metres below sea level. A 227-metre-long ship is currently being built for the company in China. It will be moved to around 30 km off Papua New Guinea to mine the Solwara 1 deposit which is already being explored by the company. It is the size of around 15 rugby fields and sits in the seafloor at 1600 metres. Mining operations are planned to start in early 2018. The company also has exploration licences for deposits off Tonga and in the Central Pacific – including a site which contains around 750 million tonnes of copper, cobalt, manganese and other minerals.
“Metals mined from the sea floor tend to be of a higher grade than those from traditional terrestrial mining,” Mike adds.
“The Solwara 1 deposit contains a copper grade of nearly 8% as opposed to land-based copper mines where the grade average around 0.6%.” Nautilus will also mine for other metals including gold and silver, zinc, lead, cobalt and manganese from the sea floor.
Deep sea mining vs terrestrial mining: what’s the difference?
While there are some similarities between terrestrial and deep sea mining, mainly around materials handling, Mike says that in many ways some of their techniques have more in common with drilling for oil or gas.
“At the depths we work, everything has to be done remotely using robots via computers on deck and managed by people in a control room – virtual technology is taken on very quickly and the chances of injury are much, much less.”
Rock is disaggregated using two large machines and then a third collecting machine sends the material as seawater slurry to the surface where it is sieved in a similar way to on land. After this, the filtered seawater is returned by two smaller pipes to the same place on the sea floor to minimise the ecological impact. The returned water also powers the hydraulic pumps.
A sea of sustainabilty
“Operating in an environmentally sound way is very important to us,” says Mike. “Mining companies are an easy target for people who don’t like mining or don’t want mining to happen – even on land.”
“Our focus is to get that first project up and running and show the world that this thing is virtually invisible. We work closely with the regulator – we go above what’s required and try to set a high bar for sea floor mining. The impacts are already less than on land, but we try to manage things to a high standard. We have a much lower carbon footprint than traditional mining as we are using less energy.” He adds.
“We’re also operating at depths well below where most of the marine life is. The hydraulic oils in our machines are all vegetable oils, so they’re biodegradable. Our noise monitoring is high and we sit well under natural levels. The metals occur on the seafloor, so unlike land mining you don’t have big waste dumps next to them. The ore is sent directly to China for processing and there are no tailings.”
Mike also adds that there is no need for the damming often associated with mining which can become a long-term liability, or for moving people away from a mine site and keeping them away. “We don’t impact on fresh water, we don’t impact on people, we don’t impact on pollination, we don’t have waste dumps, we don’t have long-term liabilities. It ticks a lot of boxes.”
As well as paying the appropriate royalties, Nautilus works closely with local government and employs local people where they can. “You try to start off with as many local employees as you can, but there can be a limited number of skillsets within the local country. They do allow you to bring in experts on the understanding that you’ll be training local people to eventually do those tasks – that’s the ultimate goal. When I started working in Papua New Guinea in 1995 I remember training up young guys – some of them are now mine managers all around the world. That’s been a really good process. We’ve actually just taken on two locals to be trained to drive two new machines we’ve just taken delivery of.” The government in Papua New Guinea has 15% ownership of the project and Nautilus works closely with them. The company has also equipped 15 out of 29 local schools with running water and toilets. “We work with aid agencies as well as the government and hope that these things we’ve helped to put in place will be able to be sustained even once we leave.”
Looking to the future
“We’re the leading company in deep sea mining, we’ve got all the technology and most of the patents,” Mike says.
“I look at it like oil and gas was in the 50s when the oil and gas industry was virtually non-existent. When it started going offshore in the 60s it slowly grew and now it accounts for about 30% of the world’s oil and gas production,” he adds.
“We know there are these huge resources of copper on the sea floor – the resources on land are of a much lower grade and much harder to get. It doesn’t take much imagination to see that a significant chunk of future copper production is going to come from these very large offshore resources.”