How to get gold from water. Extracting minerals from sea water How to get gold from sea water

Despite the fact that seawater contains gold in microscopic quantities (4 mg/ton), mining it will soon be profitable. In fact, if we look at how the amount of human waste is growing, it becomes obvious that their complete processing into finished products is difficult. At the same time, the use of waste disposal products for the extraction of gold and other metals appears to be beneficial.

American researcher Henry Ball more than 30 years ago established that seawater contains gold in the form of iodide. Gold iodide (AuI) is a lemon-yellow solid with a density of 8.25 g/cm3. Decomposes into elements when heated to 177°C or under the influence of water. Reduced by sulfur dioxide or carbon monoxide to gold. Adds ammonia. It is obtained directly from elements at 100°C, by the reduction of Au2Cl6 or H with a KI solution, and by the action of hydroiodic acid on gold (III) oxide.

As a result of his research, Ball proposed extracting gold from seawater using quicklime. According to his calculations, only 1 ton of lime is required for 4.5 thousand tons of water. The principle of operation of the Balla installation was simple. At high tide, sea water enters the pool, where it is mixed with lime milk. After a certain period of time, having already been “spent” , through a drain pipe it is discharged back into the sea. The remaining sediment at the bottom is pumped into a settling tank, from where it is transported to the processing site for gold extraction.

Kirov engineer Russian V.I. proposed an even cheaper and waste-free method of extracting gold. To extract gold, he suggests using ash from thermal power plants instead of quicklime. Fly ash from thermal power plants contains at least 10% quicklime, so processing 4.5 thousand tons of sea water will require approximately 10 tons of ash. Currently, ash dumps from thermal power plants amount to more than 10 billion tons. Fly ash is used very poorly.

To implement this method, multimillion-dollar investments are required in the construction of a concrete dam, as well as the laying of pipes to drain the treated water into the sea.
A simple calculation shows that using this method is a thousand times less expensive than other methods of extracting gold from water. In addition, already at present, this method will easily pay for itself within a year. Even assuming a 20% recovery of gold from sea water. In the case of incidental extraction of rare, noble and trace metals from sea water, the payback time will be reduced several times.

The most difficult thing about this method is choosing the location for constructing a flooded pool.
The ideal location should be located close to water currents, with regular ebbs and flows, the shore should be made of hard rock (for example, granite, limestone, etc.), away from populated areas, near railway tracks.

Compliance with these requirements will reduce the cost of constructing a swimming pool.

The total amount of gold in the waters of the World Ocean is estimated at 25-27 million tons. This is extremely high. Over the entire period of time, humanity has produced about 150 thousand tons.

http://au.ucoz.net

This technology can be attributed to the hydrometallurgy of precious metals, in particular to methods of extracting gold from highly mineralized sea water or waste solutions by cementation in metallic form onto the surface of adsorbents. This technology is based on a highly efficient cementation mechanism.

Gold in water is not a myth, but a reality that does not require confirmation. Ions of element 79 of D.I. Mendeleev’s table are present in the human body, they are part of plants and, of course, water. The usual liquid is rich in noble metal, it transports gold, carries its particles along the bottom of the river, forming deposits. This water quality is what interests prospectors around the world, who enthusiastically explore rivers and streams.

Finding gold in water

Where and how to look for Au?

Gold is mined from water both in winter and summer. This element can be found using several methods, and cold weather will not stop an experienced prospector. First, you should study the algorithm of actions that will help you extract precious metal from water.

So, what should those who want to find Au do:

• Explore the area, choose a place, chat a little with the locals. Additional information will never be superfluous, for this reason it is worth carefully studying the area, looking at maps and collecting as much information as possible. Conversations with local residents will help establish where Au was found and how long ago it was.
• The gold content in water can be pleasantly surprising and even delightful, but you shouldn’t scuba dive underwater to find it. You can simply examine the rocks, study large stones, take a water sample.
• Using a tray, you need to take a sand sample or examine the bank of a river or stream for the presence of quartz pebbles. Quartz is the main satellite of gold, but you can search not only for it; pyrite and silver can “accompany” Au.

How to get gold and what devices can be used when mining precious metals:

• The water contains Au grains of sand, but they do not float with the flow, but crawl along the bottom. Over the years, grains of sand are compressed and can turn into nuggets and even deposits. A mini-dredge will help you find metal at the bottom. This is a device that works like a vacuum cleaner. The mini dredge sucks up sand and helps locate Au. The machine itself filters, washes and separates gold from impurities and dirt.
• A metal detector is another device that helps detect precious metals in a river or stream. The device is immersed in water, it can react to gold and detect a deposit at a shallow depth. They are also exploring the coastal area with the help of a metal detector.
• Our ancestors used an Au tray when washing. Initially, the devices were made from sheep skins, but later the technology changed. Modern flumes are used for working on mountain rivers and fast-flowing streams. But progress does not stand still and, despite the fact that modern trays are lighter and more convenient, they are used mainly for taking water samples.

The presence of instruments will help speed up the search and increase the chances of success. But this does not mean at all that expensive equipment is a 100% guarantee of detecting a nugget in the ground or water.

Gold in the sand

Obtaining Au from coastal sand begins with taking it for testing: simply washing it in a tray, studying whether there are grains of the yellow metal.

You can dig up more sand, immerse it in bags and pour water into them. The fact is that sand is much lighter than gold. The noble metal will immediately settle to the bottom and can be seen, but the grains of sand will continue to float in the bag.

Scheme of the possible location of gold in a reservoir

You should filter the water with sand; if there is nothing at hand that can be used as a filter, then the liquid is simply drained. It will go away along with the sand, and Au will remain at the bottom of the bag.

Precious metal is mined from sand exclusively in the summer; in winter, prospectors simply search the coastal zone, examine the stones, but do not wash the sand.

Most often, sand is simply taken for testing, it is lifted from the bottom of the river or dug near the shore. The sample helps determine whether there is Au in the selected location and how much of it there is in that location. If you manage to find more than one or two grains of gold, then you can continue your search. If the amount of yellow metal is negligible, the searchers go to another place.

At what depth can a nugget be found?

1. Gold weighing no more than one gram is most often found under a layer of sand of 10–13 cm, and it is not so difficult to get it.
2. If you lift the soil 15–30 cm, there is a chance to find a nugget weighing more than 1.5 grams.
3. If you dig down to the soil that comes immediately after the sand, you can find a whole piece of noble metal weighing more than 100 grams.

However, the extraction of Au is associated with certain difficulties and there are no guarantees that the “excavations” will end in success. For this reason, it is recommended to study the area and take samples of soil, sand and water before starting the search.

Finding gold in sea water

Extracting the precious metal from seawater has certain difficulties. They say that if you extract all the gold from the seas and oceans, its weight will be quite significant. But today there is not a single effective method that will help extract Au from the waters of the oceans and seas. But there is hope that scientists will soon succeed in this matter.

Bacteria will help extract gold from seawater. It was recently discovered that microorganisms are capable of detecting metal particles, even if there are only a few grains of Au per trillion cubic meters of water.

Bacteria precipitate metal ions and bind them together; this requires microorganisms some time.

Since this method of extraction is still in the process of research, despite all the prospects, it can hardly be called effective.

In principle, specialists in many countries have been puzzling over how to extract Au from sea water for a long time. There are several methods, but they are all considered too expensive and for this reason they are not used in the gold mining industry.

Profit and prospect

Regardless of where Au is mined, in water or on land, the gold mining industry today is assessed as promising.

Production volumes are constantly growing, geologists are searching for new deposits, and technological progress does not stand still. The invention of various types of equipment helps to restart the development of deposits that were previously abandoned and considered unpromising.

The precious metal is hidden from human eyes in the strata of the rock; a large amount of it is located deep in the bowels of the earth. Gold comes to the surface only in places of volcanic activity. For this reason, humanity has been thinking for many years not only about how to extract it from the bowels of the earth, but also how to extract the precious metal from sea water.

At the same time, over the years, people’s love for the yellow metal has not weakened. Gold attracts and fascinates, but it is not only external beauty that attracts miners and bankers.

Precious metal is a profitable investment. Quotes are constantly growing, and in times of economic crisis, the stability of gold attracts many.

Undoubtedly, the industry is developing, and Au mining is becoming a profitable business. Metal is sought out not only by employees of large companies, but also by travelers, prospectors and just ordinary people who want to solve financial problems or have a little fun.

But do not forget that metal searching at a professional level requires material investments. It is necessary to purchase equipment, gain access to information and find time to dedicate to discovering gold mines. On average, it takes at least a year to find and develop a deposit.

The amalgamation process and equipment for extracting gold in metallic form from seawater were proposed as early as 1903.

Pre-filtered seawater was pumped through a tube to the bottom of a conical funnel-shaped vessel containing mercury and divided into many sections by perforated sheets (Fig. 92). Once brought into contact with the mercury, the upward flow of water was passed through a screen to catch the fine pumice mercury, then through perforated contact sheets, and finally through an amalgamation sluice located at the top of the apparatus and designed to completely capture the amalgamated gold from the flow. The amalgam was processed using generally accepted methods (squeezing, stripping and melting).

Similar equipment was proposed by Ritter1 and differs in that the thin mercury and the gold it contains, having passed through the mesh, are captured in a corrugated device.

Ion flotation

As noted above (see Chapter IV), ion flotation is based on the ability of some heteropolar compounds to interact with ions of heavy metals, and in particular gold, to form a flotable insoluble compound. The most famous work in this direction is in relation to the sea water of Sebba (South Africa) 189 J.

Sorption

Carbon-containing materials were tested as one of the first sorbents for extracting gold from sea water. Thus, at the beginning of the 20th century, Parker established that viscous carbon-containing materials such as asphalt, bitumen, mineral resin and others have an affinity for free gold. On this basis, Parker proposed capturing finely dispersed (or so-called floating) gold from sea water by selectively fixing it on solid viscous carbon-containing beds deposited on bars and strips installed in the flow. Ensuring continuous contact of fresh water with the viscous material must be carried out by the action of the ebb and flow of the sea.

However, most researchers believe that among the carbon-containing sorbents, activated carbons are the most interesting for the sorption of gold from sea water.

The pioneers of this direction - German researchers Nagel and Baur (1912-1913), proposed using coke, charcoal and animal charcoal and some other adsorbents for the sorption of gold from sea water. In the experiments, seawater, after preliminary clarification using a sand filter (to remove suspended material and gelatinous microorganisms), was passed through a filter bed of coke, coal or other carbon-containing material using the method of free percolation or ascending filtration (Fig. 93). The enriched adsorbent was periodically removed and melted.

To reduce the cost of pumping seawater, it is proposed to use perforated containers with an adsorbent bed on board the ship, or coastal tanks with a false bottom and a layer of adsorbent covered with wire or fabric mesh, filled by the action of the tides.

In parallel with the use of a classic adsorbent (active carbons), studies were carried out with inorganic sorbents with a highly developed surface, such as freshly precipitated hydroxides (aluminum, iron, silica gel), coagulated hydrocellulose, etc. In this case, it was proposed to use coastal vats or special stands filled with inorganic sorbent and completely covered with a double layer of fibrous textile material. The stands are immersed in sea water for weeks, and often months, after which they are exposed to cyanide solutions to extract the adsorbed gold. Gold-plated stands are used repeatedly.

When investigating possible sorption methods, it was found that colloidal metallic gold is preferably recovered in this process. Therefore, it was natural to look for a sorbent that would simultaneously reduce halogen gold to a metallic state and create a freshly formed active surface. Having examined a wide range of such possible sorbents, Parker came to the conclusion that for the most complete extraction of gold from sea water, ferrous sulfate is preferable, the optimal consumption of which is 2 kg/t of water.

Subsequently, Parker received a separate patent2 for the hardware design of the adsorption method using ferrous sulfite.

The combination of the processes of halide reduction and adsorption of colloidal gold is also observed in the proposals of other researchers. Thus, Bardt recommended treating seawater with sulfite liquor (a waste product from cellulose production) as a reducing agent, followed by mixing it with a mixture of finely ground coal and atomized metal (for example, copper, iron, etc.) 3. The sediment containing noble metals was first burned ( to remove carbon) and then smelted, collecting gold in the accompanying metal.

A similar goal (reduction of halide gold and complete capture of colloidal gold) was pursued by Glazunov and his co-workers (Paris, 1928), proposing the use of sulfides, and in particular pyrites, as an adsorbent for gold dissolved in sea water.

This idea was practically realized only in 1953 by Walters and Stillman, who went their own original way. According to their proposal, the sulphide ore was piled behind a concrete wall built near the lower tide line and curved towards the shore. At high tide the ore was submerged by water, and at low tide the water percolated through the ore. This cycle was repeated many times. After a certain time, the decomposed sulfide slurry containing adsorbed gold was removed at low tide and smelted. The inventors noted that the precipitation of gold by sulfides is facilitated when seawater is exposed to radioactive elements.

Stokes later showed that a variety of natural and artificial sulfide materials could be used to precipitate gold from seawater, with antimony sulfide being very effective.

To intensify the process of gold sorption by sulfides, while simultaneously eliminating the cost of pumping sea water, Gernik and Stokes proposed a special apparatus called in the literature “antimony-sulfide trap” (since it was conceived for use as an adsorbent, antimony sulfide) or "tidal energy system". This apparatus is made in the form of an inverted U-shaped pipe, in one elbow of which there is an expansion into which an adsorbent (activated carbon or sulfides) is placed between the grids. Sea water flows through this tube under the influence of a tidal current or during the movement of a vessel to which the described apparatus is attached.

Over the past 10-15 years, a number of patents have appeared that improve the sorption extraction of gold from sea water using metal sulfides 2. The most original idea and equipment in this direction were presented by the American researcher Norris 3.

His latest invention is based on the use of freshly precipitated metal sulfide colloids adsorbed on the surface of durable organic, synthetic or natural fibers. A typical example of synthesized organic fibers is polymerized acrylonitrile or vinyl cyanide fibers. Of the natural fibers, the most suitable is Ramie fiber (Chinese nettle). Such fibers, if immersed in a thin colloidal suspension (for example, freshly precipitated zinc sulfide prepared by mixing dilute solutions of zinc chloride and sodium sulfide at a pH value of approximately 6.0), will actively adsorb a significant portion of the colloidal sulfide particles and firmly retain them on their surface .

When sorption fibers prepared in this way come into contact with poor gold-containing solutions (for example, sea water), noble metal ions are adsorbed. They can be removed from the fibers by treating with heated dilute solutions of sodium cyanide with a small addition of hydrogen peroxide or sodium hypochlorite with a small addition of hydrochloric acid. Once the adsorbed ions have eluted, the fibers can be washed and reused repeatedly after pretreatment with a zinc sulfide slurry. In addition to zinc sulfide, iron, manganese, copper, nickel and lead sulfides can be used in this process.

Long-term research by Norris has established that certain oxidizing gases, which are often dissolved in most sea waters, can adversely affect the collectors and adsorption fibers used. These gases include oxygen, nitrogen and carbon dioxide. Therefore, to achieve the greatest effect, the proposed apparatus must have a means of continuously removing such gases from the flowing seawater before it comes into contact with the collecting structure of the fibers. Moreover, due to the relatively small number of metal ions that are collected in one normal operation, as well as the complexity of processing and handling the fiber mass, it is advisable to perform all operations continuously and automatically. All these factors were taken into account in the apparatus proposed by Norris (Fig. 94).

Of particular interest to researchers is the use of natural and artificial ion exchangers to extract gold and silver from seawater.

Priority in this direction belongs to Brook, who in 1953 proposed using iron and manganese zeolites to extract silver from sea water

Later, in 1964, Bayer and his colleagues (Germany) created so-called chelate ion exchange resins, capable of extracting up to 100% of valuable metals from sea water.

Of the most recent works devoted to the use of solid ion exchangers for the extraction of gold from sea water, the most interesting is the study of a group of experimenters from the Guff Research and Development Company (USA).

To collect precious metals, it is proposed to use a water-insoluble ethylene polymer containing pendant carboxylate or amide groups. One of the best ways to obtain this polymer is the saponification of an ethylene alkyl acrylate copolymer or the synthesis of a copolymer of ethylene and an ester of acidic groups, including maleic, fumaric and taconic acids. The production of such sorbents is described in detail in the patent.

Upon reaching a sufficient degree of loading of the polymer film, sorbed gold can be extracted by smelting from ash after burning the polymer or precipitated from solutions from dissolving polymers in caustic soda (caustic soda).

The ways of using natural and artificial ion exchangers are basically the same as the sorbents discussed above, namely: installation in a stream of sea water, filtration through a bed in a vat, loading of porous containers.

Merro proposed a completely new way of using artificial ion exchangers - applying them to the hull of a ship making its commercial voyage. Upon arrival at the destination port, the ion exchange resin can be stripped from the vessel and processed. Resin processing consists of washing with acids and special elements, followed by electrolysis of the eluate containing noble metals. Regenerated resins can be used repeatedly.

The most economical proposal is to use special devices located in the hold of the ship and filled with ion exchange resins. Here it is provided that the forward movement of the vessel causes sea water to continuously flow through the vessel with the ion exchanger. This vessel should have a cross-sectional area of ​​about 9.5-10 m2, a length of 3 m and contain about 28 m3 of resin. The maximum flow rate of seawater during sorption onto the resin should be -0.8 m3 through 1 m2 of surface per minute (0.8 m/min).

At this flow rate, -12,500 tons of seawater will pass through the sorption device per day. Even when kept in water

1 mg!t of gold per day will yield 12.5 g of gold. During a year of continuous voyage, about 4.5 kg of gold, worth about $5,000, can be adsorbed.

Cementation

One of the few information about the practical application of the method of cementing gold from sea water relates to the Parker method patented in the USA. Nickel dust has been proposed as a cementitious metal. By reduction, substitution and adsorption, gold, present in both halogen and elemental forms, can be isolated from seawater.

When carrying out cementation by mixing nickel powder with sea water, it is possible to achieve a gold loading of 15 to 20% by weight. The loaded nickel powder is removed from the vat and melted.

To precipitate gold from very poor sea waters, Sneeming proposed using the increased affinity of gold for tellurium. It has been established that it is most advisable to carry out deposition with amorphous tellurium with a highly developed reaction surface. Such a cementitious agent is obtained by treating soluble tellurium salt with sulfur dioxide. Seawater is filtered through a fixed layer of amorphous tellurium. To extract the deposited gold, the enriched mass is heated to sublimate tellurium (with its subsequent capture), and the remainder is melted into gold.

There are 10 10 tons of various substances dissolved in the World Ocean, all of which are known in the earth’s crust. The Gulf Stream alone transports 3 million tons of various salts per second. In the distant past, they received from the sea in approximately the same way as today - by evaporation. Using sophisticated technology, sodium, potassium, chlorine, magnesium, calcium, bromine, and lithium are extracted.

Getting gold

For a long time, man dreamed of extracting gold from sea water. And it seemed so real that Germany was going to pay for reparations for the First World War with “sea” gold. This was done by Nobel Prize laureate F. Haber. However, despite the fact that the ship was well equipped, and the expedition was well subsidized and prepared, nothing came of it: all the gold extracted from sea water was valued at $0.0001, that is, only 0.09 milligrams were obtained from 15 tons of water .

Soviet scientist A. Davankov on the ship "Mikhail Lomonosov" obtained a milligram of gold using an ion exchange column from 500 tons of water. This, of course, is not enough, but there are a lot of ships, so it’s a matter of installing replaceable traps. Natural sorbents - sludge - have already done a similar job. In the bottom sediments of the Red Sea, silt contains 5 grams of gold per ton of sediment. Apparently, over 10 million tons of gold are dissolved in the world's oceans. This is already significant. However, this is not all gold that came from the continents. Thus, the fresh waters of some rivers contain up to 16 clarke of gold. Where is it? In the silts of coastal sediments? If so, then such deposits can be discovered.

The gold content of ocean water is estimated differently: according to S. Arrenis (1902), gold contains 6 milligrams per ton, according to G. Putnam (1953) 0.03-44, and according to 1974 data 0.04-3.4 micrograms per liter The state of the metal has been established in: suspensions of microparticles, colloids, complex ions AuCI 2 and AuCI 4, organogold compounds.

How did they try to extract gold? There are many ways: bags of pyrite were towed behind the ship; seven grams of leaded zinc filings were washed with 550 liters of water and obtained 0.6 milligrams of gold and 1.1 milligrams of silver; used as an absorbent were zeolites, permutites, coke, slag, cement clinker, charcoal, peat, wood flour, sulfite cellulose, glass powder, lead sulfide, colloidal sulfur, metallic mercury, magnesium hydroxide (In 1925, 5 milligrams of gold from 2 tons of water), ion exchange resins (A. Davankov, 1956). However, gold continues to interest people. In sea water, for 11 main ions (CI -, SO 2\4, HCO 3 -, CO 2\3-, Br -, F -, H 2 BO 3-, Na +, Ca 2+, K +) there are 99 .99 percent. Naturally, this information is quite approximate. In fact, sea water is a complex complex of ionic and colloidal solutions, mineral suspensions, gases, organic residues, etc. In addition, the composition of seawater is affected by industrial waste. Thus, the lead content has increased 10 times over the past half century. Special areas appeared - “oases of metals”.

Mining of other metals

In 1948, the Swedish ship Albatross discovered bottom sources of hot metal-bearing brines in the Red Sea. Detailed work carried out on the Discovery vessel in 1966 identified three large depressions more than 2 kilometers deep, where brines with temperatures up to 56 ° C and a salt concentration of 26 percent were encountered.

In a 200-meter-thick layer in the Atlantis II, Chain and Discovery depressions, the contents of iron, manganese, zinc, lead, copper, gold, silver, indium, cobalt, cadmium, arsenic, and mercury are tens of thousands of times higher. High concentrations of sulfides were found in the sediments at the bottom of the depressions. These sediments are underlain by barren carbonate rocks, under which basalts occur. The deposition of ores began 13 thousand years ago. It has been established that since 1964, brine levels have been increasing. So, in 1973 it reached 62° C.

Ore-bearing silts have already been estimated in cubic meters, in tons and in dollars, but practical use of this unusual type of deposit is apparently far away. In an area of ​​over 2 million square kilometers, metal-bearing sediments associated with fault zones and underwater volcanoes have also been established. Their practical significance is still unclear.

According to the most optimistic estimates, uranium reserves on land are about 5 million tons (excluding CIS countries), and the World Ocean contains 4 billion tons of this element.

The search for sorbents for some metals yielded unexpected results: titanium hydroxide sorbs chromium (accumulation coefficient 1 million), vanadium (100 thousand), manganese, iron, copper, nickel (10-100 thousand). Copper is sorbed on ion exchangers, and in A. Davankov’s experiments, silver is sorbed (2.5 milligrams per 200 grams of sorbent). Sorbents of molybdenum, cesium, thorium, radium, and ruthenium have already been tested.

It turned out that the polyethylene sorbent precipitates 9/10 of the initial amount of indium in 20 days, and chitosan (a component of the shell of crustaceans and the cover of arthropods) sorbs zinc, copper, cadmium, lead and other metals. It is interesting that nature itself suggests the method of technology: kelp concentrates iodine and aluminum; radiolarians – strontium; – nickel; lobsters and mussels – cobalt; octopuses – copper; jellyfish – zinc, tin and lead; holothurians – vanadium; some types of tunicates - tantalum and niobium. In ascidians (tunicate litter) the concentration of vanadium is 10 10 (the metal is part of the pigment). Japan refused to import vanadium as it began to obtain it from the sea, using sea squirts.

Experts from the Faculty of Chemistry of Moscow State University claim that in recent decades the volumes of mining and processing of minerals have become almost comparable to their reserves in the earth’s crust. Forecasts are especially pessimistic for metals such as silver, tin, cobalt, uranium, and mercury. Their reserves may be depleted in the next half century. One of the most acceptable options for solving the problem of raw material shortages today would be the development of the resources of the World Ocean. According to Doctor of Chemical Sciences, Professor Georgy Lisichkin, “modern science knows how to obtain a whole range of metals from sea water using traditional chemical methods.”

Seafood

The world's oceans cover almost 71 percent of our planet's surface. This vast territory contains all the minerals known on earth - either dissolved in water or resting on the bottom in the form of sediments. Scientists have calculated that every liter of sea water contains 35 grams of minerals. “At the same time, ocean resources are constantly increasing due to the fact that rivers and precipitation carry a huge amount of debris into the seas,” says Georgy Lisichkin. “As a result of the erosion of the earth’s surface alone, 3.3 billion tons of solid matter enter the ocean annually. Approximately more four million tons per year of sediments of cosmogenic origin. It is reliably estimated that the annual addition of minerals to sea water exceeds the amount of resources extracted from the earth's surface, and their use will help meet any reasonable resource needs of mankind for hundreds of years to come."

In addition, the undoubted advantage of exploiting the World Ocean is the constancy of the composition of sea water, which allows the use of the same resource extraction technology in different areas of the planet. A big plus is the availability of offshore “deposits”. Thanks to the enormous length of the coastline, there is no need for expensive and labor-intensive prospecting and geological exploration work. Finally, marine raw materials are already prepared for hydrometallurgical processing - no complex and environmentally hazardous operation of opening the ore is required.

Scientists have long been looking for ways to take advantage of such wealth, and some have already been achieved. For example, during the Soviet era, the military-industrial complex financed scientific developments for the extraction of uranium from sea water. Today it is already a well-established technology. Only if during the Cold War most of the uranium (not necessarily extracted from sea water) was used for the production of nuclear weapons, today its extraction is relevant for ensuring the operation of nuclear power plants.

Thanks to scientific developments, the oceans today generously provide humanity with magnesium. In total, about 200 thousand tons of this metal per year are extracted from sea water - almost half of the world's production.

It would not be an exaggeration to say that scientists from different countries are ready now to begin an attack on the riches of the World Ocean. For example, Russian chemists and geologists are confident that in addition to uranium and magnesium, it is quite possible in the near future to extract copper, chromium, vanadium, molybdenum, cobalt, silver and even gold from sea water. In Russia, simultaneously, specialists from several research institutions - Moscow State University, the Institute of Geochemistry and Analytical Chemistry named after. V.I. Vernadsky RAS, Kola Scientific Center RAS - are studying this possibility. And some of the projects they have developed seem very promising.

For example, the Institute of Geochemistry and Analytical Chemistry has created an automated demonstration installation for integrated waste-free processing of seawater. The main stages of the technology have passed pilot tests at installations installed in the Sea of ​​Okhotsk and the Sea of ​​Japan, at the Sakhalin State District Power Plant and one of the Vladivostok thermal power plants. The result of the tests was experimental confirmation of the possibility of extracting pure salts of magnesium, potassium, sodium, bromine, lithium and valuable microcomponents from sea water. The essence of the method is the processing of sea water with cheap, reagent-free sorbents - substances that can “pull out” useful minerals.

In principle, scientists from many countries are working in this direction today, especially those that cannot boast of the wealth of their mineral resources. For example, the following project is being implemented in Japan. In the waters of the Sea of ​​Japan, “capsules” charged with sorbent granules are placed in the form of pipes, successfully drawing out metals. A similar technology is successfully used here - at the experimental Kola tidal power station.

To date, several dozen designs for seawater processing plants have been developed. Some of them amaze with their scale and originality. Swedish scientists, for example, have proposed a project for an underwater complex in the shelf zone, the basis of which is an underwater dam built at a depth of 200 meters, blocking the ocean current. In Italy, a project was put forward for underwater installations with working elements in the form of networks made of polymers that absorb microelements. If such networks are installed in straits with sufficiently intense currents, then, according to the authors of the project, the problem of metal extraction would be fundamentally solved.

It is clear that interest in the topic is high. However, today an objective assessment of the relevance of such projects is necessary.

Pure gold

At the beginning of the twentieth century, Nobel Prize laureate German Fritz Haber, who received an award for the synthesis of ammonia, attempted to extract gold from sea water. When Germany lost World War I, reparations were imposed. The scientist, having received government approval, organized an expedition to cover debts with gold extracted from ocean water. The mission was a fiasco. In the 1920s, scientists mistakenly assumed that the concentration of gold in seawater was ten times greater than it actually was. It was this figure that Haber started from when he began his research. As a result, he received several grams of metal after several months of expensive work. Then it was concluded that it was much more profitable to extract gold from rocks worked out in mines.

Modern studies show that the concentration of gold in the bottom sediments of the oceans (Atlantic, Arctic) in some places exceeds the so-called minimum industrial value (for continental placers), and they are therefore of interest in the future. And according to calculations made by specialists from Moscow State University, if the gold contained in sea water is completely extracted, then for each inhabitant of our planet there will be 1.2 kilograms of the “despicable metal”!

So can the ocean also supply humanity with gold along with other metals? “In the 90s, several research vessels carried out special sampling in the waters of the northwestern shelf of the Black Sea, which ensured the complete capture of gold particles, including dust-like ones,” says Vladislav Reznik, Doctor of Geological Sciences, employee of the Geological and Geographical Faculty of the Odessa National University - Gold was found in most samples, and in the paleoliman section of the Dnieper River there was an average of about 0.436 grams per ton of water. Thus, we can talk about the existence of the Azov-Black Sea gold province, covering the shelf and the adjacent land. reach 0.5 mm, and the shape is varied, and among them, apparently, there are both particles carried by rivers and native gold flakes.” Today, Russian and Ukrainian scientists would not be averse to resuscitating such research, but they are held back by an extremely meager expeditionary base.

However, it may not only be a matter of finances. Georgy Lisichkin, for example, believes that, despite all its attractiveness, the extraction of gold from sea water is not in the foreground among researchers today. Much more interesting, in his opinion, would be to look at the mysterious ferromanganese fields in the World Ocean, the reserves of which are estimated at hundreds of billions of tons. There are many difficulties in developing these fields. First of all, there is a great depth of occurrence. It is necessary to find new engineering solutions, since the modern technology of lifting raw materials to the surface of the ocean using winches and dredges is very labor-intensive and unproductive.

Russian research vessels may soon go to the Atlantic to study ferromanganese fields, and a number of domestic research institutes are starting to develop projects for surface mining complexes, as well as underwater robotic systems that could search, mine and transport metal to floating bases without human intervention.

Humanity is still taking only the first steps in the development of the ocean and its resources. Reflecting on the industrial invasion of the World Ocean, scientists recall that all oceanic processes, from the molecular level to planetary ones, such as currents and cyclones, are connected by a single hierarchical system. In accordance with the laws of ecology, any intervention in the natural system at the lowest molecular level can result in an environmental disaster. Alas, scientists cannot completely exclude the possibility of negative consequences.