First deep-sea mining licence granted

Wired.co.UK: First deep-sea mining licence granted
Papua New Guinea's government has granted the world's first deep-sea mining licence to a Canadian company named Nautilus Minerals, who want to operate in the Bismarck Sea.

The company's Solwara 1 project sits at 1.6km below the surface of the sea, 50km north of the nearest port, the volcano-threatened Rabaul. Early surveys have found high-grade copper and gold deposits close to the sea floor, which Nautilus reckons will be lucrative enough to exploit on a commercial scale.

The technology behind the process is complex. It takes aspects from undersea oil and gas exploration, combines dredging processes and adds a smattering of the kind of principles that govern open pit mining.

A preparatory machine called an "auxiliary cutter" (AC) flattens out the sea floor to create a surface that a "bulk cutter" (BC) can operate on, ripping the ore apart. That ore is then left on the sea floor and collected by a "collecting machine" (CM), which sucks it up into a tube and pushes it through a pipe to the "riser-and-lifting system" (RALS), which sends it to a boat at the surface. On the deck of the boat, the slurry coming up from the sea bed is filtered, with the water then being sent back down the pipe to the seabed, where it's released. A transportation barge then hauls it to a stockpile in the port of Rabaul.

As it's a relatively new process, the environmental impacts of a full-scale deep sea mining operation aren't yet known. There's concern that sediment plumes and increased toxicity of the water column could result, as well as significant and permanent damage to ecosystems in the Benthic zone, and the deep-sea organisms that inhabit it. We know very little about such organisms, as almost all observation must be done by remote-controlled submarine. There's also concern about leakage, spills and corrosion from the equipment used to conduct the mining.

The lease has been granted for an initial term of 20 years, which Nautilus hopes will be sufficient time to get out enough of the 2.2 million tonnes of mineralised material thought to be in the area. It'll take a while to get up to speed, though -- about two and a half years for the project to become commercially viable. If it proves successful, Nautilus also has its eye on the territorial waters of Fiji, Tonga, the Solomon Islands and New Zealand, which may also harbour commercially exploitable minerals.