1. Minerals:
There are about 50 billion tons of various minerals stored in the ocean. If it is laid on the ground, it will be up to 200 meters thick; if it is loaded on a train, its length can be from the earth to the sun.
Magnesium metal plays an important role in industry and national defense. The main material for manufacturing aircraft and speedboats is aluminum-magnesium alloy. Magnesium is lighter than aluminum. A large part of the world's sources of metallic magnesium and compounds comes directly and indirectly from seawater.
Manganese nodules are a famous deep-sea mineral. They look like potatoes. When sliced, the layers look like onions. Such nodules often have shells, corals, fish teeth, and fish bones as the core, with other materials gathered around them. The growth rate is very slow, about 1 mm in 1000 years, and some only grow 4 mm in 1 million years. Manganese nodules contain more than 20 elements such as manganese, iron, nickel, and cobalt, and their economic value is very high. Around 1980, more than 500 manganese nodule mining areas with economic prospects were discovered at the bottom of the world's oceans, with total reserves ranging from 1.5 trillion tons to 3 trillion tons, with the Pacific Ocean having the highest taste. The content of some rare dispersed elements and radioactive elements in manganese nodules is also very high, such as beryllium, cerium, germanium, niobium, uranium, radium and thorium. The concentrations are thousands, tens of thousands or even millions higher than those in seawater. times.
The total iron ore reserves at the bottom of the world’s oceans may reach about 300 billion tons. Potassium ranks 6th in seawater, with a total of 600 trillion tons. Bromine 99 and above are all in the sea and are marine elements, with total reserves of 100 trillion tons. The total reserves of iodine in the oceans are around 93 billion tons, much more than those on land. Iodine has important uses in cutting-edge science and military industrial production.
There are dozens of rare elements in seawater, and many of them are elements with small reserves on land and scattered distribution but with great value. For example, ammonia and cesium are raw materials for manufacturing photoelectric tubes, which are important components of modern automation equipment. Both rubidium and cesium have very small reserves on land, but there are relatively large reserves in seawater. There are 190 billion tons of rubidium in seawater. Boron or lithium hydride can be used as high-energy fuel for rockets. The reserves of boron in seawater are more than 7 trillion tons.
When walking on the beach, there may be rich mineral deposits in the rustling sand. They include diamond, gold, platinum, cassiterite, rutile, ilmenite, chromite, magnetite, ruby, sapphire, amber, zircon, etc. Sand mines are either in shallows or in places with water depths less than 150 meters. Coastal sand mines have the advantages of wide distribution, many types of minerals, large reserves, low industrial grade requirements, convenient mining, simple mineral processing, and low investment. In the development of seabed mineral resources, their output value is second only to seabed oil.
The ocean is also rich in energy minerals such as coal, oil and natural gas. There are about 200 submarine coal fields discovered in the world, mainly distributed in Australia, the United Kingdom, Bulgaria, Greece, Ireland, Iceland, Canada, Turkey, Finland, France, Chile, Japan and the offshore waters of my country. In the 1980s, the average annual amount of seabed coal extracted in the world was about 70 million to 80 million tons, accounting for about 2% of the world's total coal.
Marine geology experts estimate that 250 billion tons of oil are stored under the sea, which is three times larger than the oil storage on land. In the 1990s, more than 600 million tons of oil were produced. Uranium reserves in seawater are approximately 4 billion tons, more than 4,000 times those on land. When 1 gram of tritium is fused into helium, it can produce 10 degrees of electricity. The total amount of tritium in the ocean is estimated to be about 2.5 billion tons, a huge potential source of energy.