Manganese nodulesPolymetallic nodule, manganese ore balls, manganese ore clusters, manganese nodules, etc. It is a kind of iron and manganeseoxideThe color is usually black and brown black.Manganese nodules have various forms, including spherical, elliptical, potato, grape, flat, slag, etc.The size of manganese nodules also varies greatly, ranging from a few microns to tens of centimeters, and the largest one weighs tens of kilograms.
The ocean floor is rich in mineral resources,manganeseTuberculosis is one of them.Manganese nodule is a kind of ore deposited at the bottom of the ocean. Its surface is black or brown, and its shape is spherical or massive. It contains more than 30 kindsmetallic elementAmong them, manganese, copper, cobaltnickelEtc.
The content of various metal components in manganese nodules is about: manganese (27-30%), nickel (1.25-1.5%), copper (1-1.4%) and cobalt (0.2-0.25%) with economic value.Other components include iron (6%), silicon (5%) and aluminum (3%), as well as a small amount of calcium, sodium, magnesium, potassium, titanium and bariumhydrogenandoxygen。
76 metal elements such as copper, cobalt and nickel are scarce on landmineral resources, it is necessary to mineSubmarine manganese noduleGet these metals.The United States depends on imports of manganese ores, and is also interested in producing manganese from manganese nodules. Therefore, the United States attaches most importance to the development of manganese nodules.The United States is also a leader in the development of ocean manganese nodules.
Source of formation
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manganese nodule
Its material sources are roughly in four aspects:
One is from land, mainland or islandRock weatheringAfter that, iron, manganese and other elements will be released, and some of them will beocean currentTo the ocean.
Second, fromvolcanoWhen a large amount of gas generated by magma eruption interacts with seawaterLavaA certain amount of iron and manganese will be removed from the sea, so that more and more manganese and iron will be found in the sea water.
The third is from biology,planktonTrace metals are enriched in the body. When they die, the body decomposes and the metal elements enter the sea water.
Fourth, it comes from the universe. Relevant data show that the universe will drop 2000~5000 tons of cosmic dust to the earth every year. They are rich in metal elements and enter the ocean after decomposition.
reason
As for the formation reason of manganese nodules, it is generally believed that the oxides of various metals deposited on the sea floor are formed in the form of polar molecules, under the effect of electronic gravity, with the small particles of other objects as the core, and are constantly gathered.This theory can not justify itself.The content of manganese in seawater is not much, why does it take the lead in manganese nodules?The origin of manganese nodules needs further study.
There are also many mining methods for manganese nodules studied and tested.The more successful methods are chain bucket method, hydraulic lifting method and air lifting method.The chain bucket excavator is just like the old agricultural waterwheel, which uses the winch to drive the rope chain with many buckets to constantlySubmarine manganese noduleCollect them on the working boat.
Metal composition in manganese nodules
Hydraulic lifting typeundersea miningMachinery is to use water power to suck up manganese nodules from the seabed with mud and water through ore pipelines.The air lifting method is the same as the hydraulic lifting principle, but the manganese nodules are directly sucked onto the mining workboat with high-pressure air, mud and water.
In the 1980s, multinational companies formed by mineral enterprises in the United States, Japan, Germany and other countries used these machines to achieve a daily output of 300~500 tons of manganese nodules.In terms of smelting technology, the United States, France, Germany and other countries have also built pilot plants to treat more than 80 tons of manganese nodules per day.In a word, the mining and smelting of manganese nodules are technically no longer a problem. Once it is economically advantageous, it can form a new industry and enter into large-scale production.
Manganese nodules are widely distributed in the surface layer of the world's oceans at depths of 2000~6000 meters, and the quality generated at the depths of 4000~6000 meters is the best.The total reserves of manganese nodules are estimated to be more than 300 billion tons.Among themNorth Pacific It has the widest distribution area, with reserves accounting for more than half, about 1700 billion tons.In places where manganese nodules are concentrated, there are more than 100 kilograms per square meter, which is literally one by one covering the seabed.Its total reserves in the world's oceans are three times of ten to the 12th power.
More than 50% of manganese nodules areferric oxideAnd manganese oxide, as well as more than 20 elements such as nickel, copper, cobalt, molybdenum and titanium.As far as the reserves at the bottom of the Pacific Ocean are concerned, this manganese nodule contains 400 billion tons of manganese, 16.4 billion tons of nickel, 8.8 billion tons of copper and 9.8 billion tons of cobalt, and its metal resources are hundreds or even thousands of times of the total reserves on land.If calculated according to the world metal consumption level in 2006, copper can be supplied for 600 years, nickel for 15000 years, manganese for 24000 years, and cobalt for 130000 years. If they are fully mined, manganese can be supplied for 33300 years, nickel for 25300 years, cobalt for 340000 years, and copper for 980 years.What a great fortune this is!Moreover, this kind of nodule grows very fast, accumulating at the rate of 10 million tons every year. Therefore, manganese nodule will become an inexhaustible "autogenetic mineral" for human beings.How are manganese nodules formed?Scientists estimate that the earth has a history of 5 billion years, and in this process, it is constantly changing.Through the crustMagmaAnd hydrothermal activity, as well as surface denudation, transportation andSedimentation, forming a variety of mineral deposits.The erosion of rainwater caused some minerals dissolved on the ground to flow into the sea.In seawater, manganese and iron are originally saturated. Due to this river entrainment, the content of these two elements increases continuously, resulting in supersaturated precipitationColloidal stateThe hydrous oxide of is precipitated.In the process of sedimentation, copper, cobalt and other substances are adsorbed in many ways to form nodules with rock debris, marine biological remains, etc. After sinking to the sea bottom, they roll together with the bottom current, like a snowball, rolling bigger and bigger, rolling more and more, forming manganese nodules of different sizes.
It is estimated that the total amount of manganese nodules at the bottom of oceans in the world may be 3 trillion tons, and that of manganese nodules at the bottom of the Pacific Ocean alone is 1.7 trillion tons, including 400 billion tons of manganese, 16.4 billion tons of nickel, 8.8 billion tons of copper, and 5.8 billion tons of cobalt.
Utilization value
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Some manganese nodules contain 55% manganese. In addition to manganese, they also contain more than 20 kinds of metal elements, such as iron, nickel, copper, cobalt and titanium, all of which are very high.The metals rich in manganese nodules are widely used in various aspects of modern society.For example, manganese metal can be used for manufacturingmanganese steelIt is extremely hard and can resist impact and wear. It is widely used in making tanks, rails, crushers, etc.The iron contained in manganese nodules is the main raw material for steelmaking. The metal nickel contained in manganese nodules can be used to manufacture stainless steel, and the metal cobalt contained in manganese nodules can be used to manufacture special steel.It contains a large amount of metal copper which is used to make electric wires.Titanium contained in manganese nodules has low density, high strength and high hardness. It is widely used in aerospace industry and has the reputation of "space metal".Manganese nodules not only have huge reserves, but also grow continuously.The growth rate varies from time to place, with an average length of 1mm per thousand years.Based on this calculation, the global manganese nodules increase by 10 million tons every year.Manganese nodules can be called "inexhaustible" renewableMetallic mineralsresources.
Manganese nodules contain a variety of strategic materials, which will inevitably lead to competition for resources.In 1978, the Japanese mining ship used suction and pneumatic lifting to collect manganese nodules successfully.The United States has used 200000 tonnage mining ships to collect data with automatic control equipmentSouth Pacific Bottom manganese nodules.
Ore discovery
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From 1872 to 1876, a British three masted sailboat called "Challenger" made an investigation at sea for more than three years. The investigation yielded a lot. The team members brought back some dark things like tumors, which were fished from the seabed in different regions. At first, no one knew what they were, so they took them to the laboratory for analysis,It was found that the main component of this tumor like gadget was manganese, so some people called this black gadget "manganese ore tumor". Because it was also like the tuberculosis of tuberculosis patients, it was later called manganese nodules or metal nodules.
Later, AmericanOceanographerAfter hearing the harvest of the British expedition, they also sent people to look for this mineral in the Pacific Ocean seabed. Once, a 57 kg manganese nodule was found on the seabed near Hawaii.More coincidentally, it was an article of the Oceanographic SocietyUnderwater cableIn the process of repairing the cable, they found a larger manganese nodule, which weighed 136 kg.Unfortunately, these people thought it was too heavy. They only drew a picture of it, and then threw it into the sea. As a result, an excellent manganese nodule specimen failed to enter the Marine Museum.
Deep-sea manganese nodule
Soon,Former Soviet UnionThe Vityaz expedition also found ferromanganese nodules containing iron and manganese at the bottom of the Indian Ocean.But, inthe Second World WarPreviously, people were not very interested in these things in the deep sea. First, manganese andironI don't feel lack of them. Second, it's very difficult to get these things at the bottom of the sea, and I don't think it's worthwhile.But after the Second World Warmanganese steelMore and more, manganese (as well as coppernickel, cobalt, etc.).So people think of these treasures at the bottom of the sea.In particular, the United States, France, Germany, the former Soviet Union, Japan, New Zealand, India and other countries have carried out a lot of exploration work on deep-sea manganese nodules, and all want to get these metal ores out of the seabed.You should know that some manganese nodules contain as much as 50% manganese and 27% iron.In some manganese nodulesmanganese dioxideThe content reaches 98%. It can even be directly used to produce aBattery。
Development and utilization
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abroad
In the early 20th century, the United StatesMarine survey vesselThe Albatross picked up manganese nodules in many places in the eastern Pacific Ocean, and made a preliminary estimate that the area of manganese nodules at the bottom of the Pacific Ocean is larger than that of the United States.However, people did not pay much attention to it at that time.
In 1959, John Merrow, an American scientist who has been engaged in the research of manganese nodules for a long time, published his research report on the feasibility of commercial development of manganese nodules, which attracted the attention of many governments and metallurgical enterprises.Since then, the investigation and exploration of manganese nodule resources have been carried out on a large scale.The research and test of mining and smelting technology are also advancing rapidly.Countries with large investment and remarkable achievements in this field include the United States, Britain, France, Germany, Japan, Russia, India and China.By the 1980s, there were more than 100 companies engaged in the exploration and development of manganese nodules around the world, and 8 multinational corporations had been established.
China
China began to investigate oceanic manganese nodules in the mid-1970s[1]。
Deep-sea manganese nodule
In 1978, "Xiangyanghong No.05"Marine survey vesselManganese nodules were first recovered from the seabed at a depth of 4000 meters in the Pacific Ocean.Since thenChinese oceanographic survey shipThere are also "Xiangyanghong 16", "Xiangyanghong 09", "Haiyang 04"“Dayang No.1”Etc.After years of investigation and exploration, a rich mineral area with recoverable reserves of 2 billion tons has been proved in the central Pacific sea area in the southwest of Hawaii, 7 to 13 degrees north latitude and 138 to 157 degrees west longitude.
July 28 and 30, 2011, 5000m in ChinaJiaolong manned submersibleSuccessfully completed the third and fourth launching missions of the 5000 meter sea trial. After successfully diving 5000 meters, Jiaolong brought us back 5000 metersSubmarine manganese noduleThis is also the first exposure of 5000m seabed manganese nodules.At the same time, the Jiaolong brought back 5000 meters of seabed manganese nodule samples, which was an important step for China to develop seabed manganese nodule ore sources.
Ferromanganese nodules on the seabed photographed by Jiaolong
On July 3, 2013, the Jiaolong manned submersible, which was on its first pilot application voyage, dived in the Jiaolong Seamount area of the South China Sea and found a large area of ferromanganese nodules on the seabed.The Jiaolong brought back eight ferromanganese nodules, five of which were slightly larger than eggs, and three of which were larger than adult fists, with black surface.
In the ferromanganese nodule sample, one piece was crushed by the submersible manipulator.Zhou Huaiyang, a professor of Tongji University, pointed to the sample and said to the reporter, "The inner core is volcanic lava, and the outer circle is ferromanganese oxide, which has been formed for tens of thousands of years. If you polish it, you can see that the outer circles are like tree rings, and the specific history of this nodule needs to be measured in the laboratory."
According to the plan, the Jiaolong will dive twice in this area to continue its scientific investigation of the Jiaolong Sea Mountain.
"It's a pity that no rock samples were collected this time, and we hope that the next two dives can make up for this shortcoming." Zhou Huaiyang said, "The formation time, formation mode and material source of the South China Sea are still in doubt, and seamounts are closely related to the formation of the South China Sea basement.The age determination, composition analysis and spatial-temporal change analysis of the rock samples from seamounts can help solve this major scientific problem. "
