Given that they cost lass energy to refine than their counterparts found on land, should we be mining the seabed for rare but useful minerals like tellurium?
By: Ringo Bones
The late eccentric billionaire Howard Hughes started an exploratory venture of deep sea seabed mining during the late 1960s and early 1970s but didn’t prove to be economically viable at the time because technology used for such an undertaking were still at its infancy. But given the advances of autonomous undersea craft in the 21st Century, should we be exploring the viability of deep sea seabed mining because minerals used in renewable energy production like rare earth magnets used in wind turbines and tellurium used in advanced photovoltaic solar panels costs less energy to process and extract in comparison to their land-mined counterparts? But first, here’s a brief primer on the relatively rare element called tellurium.
The element tellurium was first discovered by Müller von Reichenstein in 1782, by Martin Heinrich Klaproth in 1798 and by Jakob Berzelius in 1832. On land, it is usually found in sulfide ores of copper and silver at 0.0000002-percent abundance. With both metallic and nonmetallic traits, tellurium has several peculiarities. It is “out of step” in the periodic table having a lower atomic number but higher atomic weight than iodine. It wasn’t produced in industrial quantities until the 1920s because it has a very negative effect on the human physiology. As tellurium enters your body, either by inhalation, ingestion or via skin absorption, our physiology turns it into mercaptans for easier excretion from our bodies. Unfortunately, tellurium based mercaptans smell like human turds mixed in with rotting garlic and until it is completely excreted from your body, you would become a social outcast for about two weeks. Taking a shower only makes the tellurium mercaptan smell worse, which explains why tellurium and its compounds are only processed in an isolated and/or hermetically sealed space.
Recently, British scientists exploring an underwater mountain in the Atlantic Ocean have discovered a treasure trove of rare earth minerals in a Tenerife undersea mountain known as the Tropic Seamount located more than 500 kilometers (300 miles) away from the Canary Islands. Samples brought back to the surface contain not only a high concentration of rare earth elements but also a scarce element called tellurium used in newfangled super-efficient photovoltaic solar panels at concentrations 50,000 times higher than in deposits found on land. Given that rare earth metals are used in powerful magnets that made low carbon energy generation a reality, should we be mining the seabed despite of the largely unknown ecological consequences?
Dr. Bram Murton, the leader of the expedition, told the BBC that he had been expecting to find abundant minerals on the Tropic Seamount but not in such high concentrations. Dr. Murton calculated that the 2,670 metric tons of tellurium on this single seamount represents one-twelfth of the world’s total supply. And Dr. Murton has come up with a hypothetical estimate that if the entire deposit could be extracted and used to make solar panels, it could meet 65-percent of the UK’s electricity demand. One major concern is the effect of plumes of dust stirred up by the excavation of the ocean floor, spreading for long distances and smothering all life whenever it settles. To understand the implications, the expedition to Tropic Seamount conducted an experiment, the first of its kind, to mimic the effects of mining and to measure the resulting plume. The researchers hope that the environmental impact outweighs the resulting carbon dioxide reduction as we intensify the shift to more renewable energy generation.