What happens to gold in the ocean

Manganese nodules

Much more than just manganese ...

Manganese nodules contain the metals manganese and iron, but also the economically interesting elements copper, nickel and cobalt. These metals are not very common in the earth's crust and are mainly used in steel processing and the electrical industry.

There are also traces of other important elements such as platinum or tellurium for the manufacture of computers and mobile phones.

Germany itself has no deposits of copper, nickel or cobalt. So far, they are 100 percent imported from countries such as Chile, Russia and the Democratic Republic of the Congo. Each ton of manganese nodules contains on average twice as much copper, nickel and cobalt as one ton of ore on land.

Manganese nodule fever among the states

The bottom of the deep sea is littered with manganese nodules. They lie at a depth of 5000 meters on the sea floor. The highest density of tubers is found off the west coast of Mexico, in the Peru Basin and in the Indian Ocean. Manganese nodules grow extremely slowly, just five millimeters to one centimeter in a million years.

So far there has been little interest in the minerals on the seabed, but as raw material prices rise, marine mining is becoming more and more interesting for industry. When world market prices for raw materials threatened to explode for the first time in the 1970s at the time of the oil crisis, a manganese nodule fever broke out worldwide. Special companies developed deep-sea robots and haulage vessels to collect the tubers from the deep.

First degradation test in the 1970s

In March 1978, manganese nodules were successfully pumped to the sea surface via a long hose for the first time - a great moment in deep-sea mining. The degradation is technically not a problem, but researchers are still unable to estimate the effects on the marine ecosystem.

The traces of the mining equipment from back then are still clearly visible on the sea floor, as if an excavator had just passed through there yesterday. It was just a small test.

A total of 800 tons of manganese nodules were pumped up at the time. However, the geologists had calculated that around 5000 tons per day would be necessary for deep-sea mining to be worthwhile. The amount of tubers promoted was not sufficient and the promotion was stopped for the time being.

Deep sea habitat in danger

Manganese nodules lie on hardly solidified sediments in the deep sea. As soon as something is removed from the tubers, the ground is stirred up.

Even if geologists and researchers were to use a kind of vacuum cleaner instead of a rake to break down the tuber fields: A huge amount of sediment, water and countless living beings would be extracted one way or another. The encroachment on the habitat would therefore be considerable.

It has not yet been clarified whether and how the harvested areas will be repopulated. So which technology is best suited for mining remains to be found out.

Germany's 17th state

Since 2001, the United Nations International Marine Agency has issued licenses to explore manganese nodule fields. It is not yet a question of mining, just a detailed examination of the potential mining areas.

Germany has also secured a deep-sea license in the Pacific. In addition to the German license area, there are those of South Korea, Russia, Cuba and France.

The exploitation of the deposits in the deep sea is very expensive. Therefore it will take a while before the mining of the manganese nodules could really be worthwhile for the industry. Raw material experts estimate that the comparatively easy to extract global cobalt and nickel deposits on land will last for around 60 years.