Gold is by far the most expensive metal. The relevance of its production over the past 100 years has not changed, only the methods have changed. Previously, it was enthusiastic gold diggers with a tray in hand. Now they have been replaced by a dredge for gold mining - special industrial equipment.

What is a dredge

The dredge is a mechanism for separating gold from the ground. Nowadays, it occupies a leading position among both individual and industrial gold miners as a means for washing the precious metal. The reason for this lies in the simplicity of the design and at the same time the high performance of the dredge.

Dredge features

Not every deposit is suitable for gold mining by dredge. Gold miners should consider the following features:

• Recovery of gold is possible only in reservoirs: rivers, seas, and so on. The dredge device is to blame (which we will consider in more detail below). The fact is that in water, rock particles weigh several times lower than in air. Accordingly, much less energy is required to lift them from the depths of the rivers. When mining in open areas, it is necessary to significantly increase the power of the pump and electric motor, which is not advisable due to a significant increase in the size and weight of the dredge.
• The need to conduct a study by geological surveys of the area for the presence of gold ore. The dredge itself does not have sensors and mechanisms for finding gold. Its function is only the separation of metal from the ground. It is worth noting that today the deposit is considered financially profitable if there are 3 grams of gold per 1 ton of rock.
• Not all soil types are suitable for gold mining by dredge. Here, the size of the rock particles is more implied, rather than their chemical composition. The reason for this is the limitation of the size of the suction hoses through which the soil is pulled from the bottom of the reservoirs.

Dredge device

As mentioned earlier, the design of the dredge is nothing complicated.

A minimum of electrics, a maximum of parts from an ordinary technical store. So, the following components of the dredge are distinguished:

1. Suction tip. It looks like a tapering cone. It is made from thin sheet steel with a thickness of not more than 2 mm. The edges of the tip are fastened by manual arc welding. Different diameters of the bases of the cone are necessary to increase the suction area on the one hand, on the other hand, for faster transport of soil to the surface of the water.
2. Supply hose. As a rule, it is represented by a high-pressure hose with a diameter of at least 12 centimeters. This size is associated with the limitation of the dredge by weight. To increase the rigidity and strength of the hose, a metal frame is interspersed in its base.
3. pressure hose. The same sleeve, but with a diameter of 50 millimeters. The main purpose of this unit is to supply clean water for washing and transporting gold with soil.
4. Pump. Provides direct pressure for flushing water. Not every pump is suitable for this. Here, the most important parameter is the preservation of performance when large soil particles enter the working cavity. Diaphragm, vane and gear pumps have proven themselves in the best way.
5. Electric motor. Needed to transmit torque to the pump. Usually, asynchronous three-phase motors are used, as the most convenient in operation. Their power depends on the performance of the installation. For a small-sized dredge, 2 hp is enough.
6. Flushing sluice. It is a curved container. The lock serves as a place for screening out gold particles from rocks. It is made of thin-sheet materials: steel and aluminum, in the case of a lightweight design.
7. Gutter. A vessel where the deposited gold is directly collected.
8. Source of electricity. Required to supply electric current to the motor. It can be either a battery or a gasoline generator. In the case of large industrial scale production, a power line is connected to the dredge.
9. floating platform. Serves as a frame for the installation of all the above equipment. Another function of the platform is to keep the dredge buoyant on the surface of the reservoir. Stability afloat is maintained by large tanks filled with air. The platform is made from structural materials. Most often it is aluminum.

Principle of operation

Gold ore particles are cleaned from rock in several stages:

• The electric motor turns on and the pump directs water into the pressure hose, thereby discharging the space between the river water and the suction nozzle.
• Due to the created vacuum, the soil is drawn in by the suction nozzle and moves through the supply hose to the flushing sluice.
• Once there, the soil with water passes through a certain system of drops. The goal here is to separate the denser gold from the less heavy rock particles.
• Further, after a certain time, the gold settles in the gutter, and the remaining soil is removed into the river along with the washing water.

Before the direct start of the washing process, the dredge is adjusted for the accuracy of capturing the precious metal. This is done by adjusting the overflow differential, flow rate and pressure of the pump.

For greater reliability of the correct operation of the dredge, a preliminary check is carried out, which consists in passing pieces of lead marked with paint through it. If colored metal is observed in the chute after passing through the dam, then the dredge is working properly. If not, it is sent back for revision.

Drag classification

There are many types of gold mining dredges. They are divided according to the following parameters:

1. Power. This refers to the depth from which the dredge can take the soil. Usually, this value ranges from 5-50 meters.

2. Portability. There are stationary and floating dredges.

2.1. Stationary dredges are powerful industrial dredges weighing up to 1,500 kg. In terms of their dimensions, they are comparable to 4-storey modern houses. They have more electronics and more control over the gold mining process. The management staff of such dredges consists of at least 10 people.

2.2. Floating - more mobile drag models. They are significantly smaller in weight (40-150 kg) and power. This drag can be handled by 1 person.

3. Screening capacity. Depending on the type of pump, the diameter of the hoses and the type of flushing sluice, it can vary from 100 to 1000 kg of soil per hour.

Other mining methods

The extraction of gold from rocks is not only done by dredge. It is also worth noting such methods as:

• Manual. A gold miner extracts gold using a conventional tray, washing the soil in it with water. This method was simple, but had very low performance.
• Ore. Production is carried out in deposits on land, using special high-tech equipment: excavators, drills, and so on.
• Hydraulic. It also includes the dredge mining method we are considering. Getting gold is carried out by washing out rocks.

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From this metal mankind goes crazy

Before you start designing or purchasing equipment for gold mining, you need to consider that as of November 2014, individuals and individual entrepreneurs do not have the right to officially search for and mine precious metals.

Although a law allowing such actions was considered back in 2011, it has not yet been adopted. Despite the prohibitions, such activities are carried out extensively in the North of Russia and in Eastern Siberia, where people in the taiga extract gold from depleted mines. The illegal production volume is about 10 tons, which is a tenth of the all-Russian annual production.

You need more than just mining equipment

Gold mining can be carried out today by enterprises that have drawn up the appropriate package of documents and received all permits, primarily a license for the right to use subsoil. In addition, the gold mining enterprise must hire workers, provide development projects for the deposit, mining and land allotment and equipment, among which the dredge occupies the main place.

This mechanism is a mining machine, which includes dredging, concentrating and other elements that allow you to remove waste rocks, leaving precious metals. The dredges work mainly in watered deposits, with the exception of viscous clays, hard rocks and boulder soils. For the dredge to work, a large amount of technical water is required, so periodically the gold mining seasons in one or another part of the globe are disrupted due to drought.

Machine for mining precious and other metals can be marine or continental class. Marine options are built on the basis of keel ships that can move independently or in tow. They are engaged in development in deep lakes, in the oceans, in the coastal zone. Continental ones are used on the continents and are formed on the basis of a pontoon, a flat-bottomed vessel.

Dredges can run on electric power, a combination of electricity and diesel, diesel, and even steam. They can take soil from depths from 6 to 50 meters below the waterline, scoop soil both with one bucket and with a whole bucket chain. By the size of the buckets, combines are divided into small (up to 100 liters) and large-capacity - about 250 liters. If the dredge works on the high seas, then it moves on an anchor-cable device. Such equipment is extremely bulky and costs a lot of money.

Flushing device for do-it-yourself mining

This is what the device looks like

Therefore, among amateur techies, discussions do not cease about whether a mini-dredge can be made by hand. Masters believe that theoretically it can. For its manufacture, a frame is made of lightweight materials (often aluminum sheets from a landfill), to which tires from trucks are attached to ensure the buoyancy of the structure. If there is a desire for a more reliable design, then a plastic pontoon is taken as the basis, including collapsible structures. This option will be more expensive and much harder. In addition, the frame can be mounted on plastic drums with a volume of about 40 liters.

An engine, a water pump, an air compressor, hoses, and a flushing chute are mounted on the frame. The latter is made by some craftsmen in the West on their own, based on their own preferences in gold mining (many countries allow work for private individuals). Many gutters are based on the “Hungarian effect”, when water forms a waterfall after the next threshold and does not foam much (so as not to lose metal elements). They are made of steel, welded together into a lattice and mounted on a specially bent aluminum sheet, which is the gateway. All elements of the gutter must be laid with the so-called prospector's moss, which is a vinyl coating that resembles spaghetti in a pattern. It retains particles of precious metals.

Western prospectors engaged in individual mining call a diameter of about 10-12 cm the preferred size of the hose. It is convenient to operate such a hose alone during washing, while a diameter of 14 cm already gives more than a significant physical load that not everyone can withstand.

The flushing process assumes that the dredge socket will be installed in the head of the lock so that water flows with soil, which is washed, enter it, and the residues are discharged into the water behind the minidredge. Water must enter the pump through the suction valve, without sand, as the presence of grains of sand can lead to damage to the pump. Therefore, an amateur dredge cannot work without a valve. At the end of the hose, an elevator with a suction nozzle is equipped.

Gold mining today is a good source of income for some people. Therefore, businessmen and entrepreneurs are considering illegal mining with the help of home-made designs. One of them is a gold mining dredge. The device is used both in industry, where it has large dimensions and processes a lot of land, and in small mining by miners. In the latter case, the device is called a minidredge.

Working principle of industrial dredge

People of different professions are involved in the exploration of places and the extraction of precious metals. The more people involved in the activity, the faster the search will be crowned with success. The minidrag will not help during the preparation for gold mining, as it does not recognize the presence of metal particles in the water. But if there is gold, it can be safely extracted using this device.

Steps before using the dredge

To understand the profitability of a business, you should familiarize yourself with the statistics. Explored sources of gold will consistently generate income for 2-3 years, and illegally explored placers will bring profit in the next decade. Although it is forbidden by law to engage in such activities, and even more so to use minidredges.

Before using the devices, it is worth carrying out the following stages of preparation for extraction:

• Exploration of the boundaries of the deposit, marking them on the map.
• Calculations and analysis of the approximate content of gold in the ground or water.
• The acquisition or lease of land on which the mines are located is the stage that officially allows gold mining. Sometimes industrial companies sell licenses to private entrepreneurs and they can use the territory for their own search. This method is the easiest, because it is known for sure that there is gold on the ground.
• If exploration was carried out independently and the land has already been bought, before using the dredge it is worth building a mine, in some cases digging a quarry.

The extraction of precious metals in industry is carried out in several ways. One of them is called hydraulic. It is based on the extraction of metal and its separation from impurities using high water pressure. But now the priority is to use the second method using a dredge for washing gold.

What is a drag?

A dredge is a device that weighs about 1.5 tons. It is similar in size to a four-story building. The device has special equipment in the form of scoops that lift the soil from the bottom. Further, the rock passes through several stages of washing and the desired precious metal is deposited. The advantages of the apparatus lie in the fact that it carries out all stages of the extraction and purification of gold. Ten people can manage the structure, while the efficiency of work corresponds to the activities of 12,000 prospectors who would mine using trays.

The dredge is used in the development of continental and offshore deposits, its peculiarity lies in the fact that it cannot work without water. In all cases, mining is carried out either on the seashore or near a river or stream, where the dredge is on a pontoon.

But only large gold miners, state-owned companies can afford to purchase a full-fledged industrial machine. This gold washing and mining apparatus is difficult to transport and install. Therefore, it is important to evaluate the initial amount of the precious metal in the ground for the payback of production.

Minidrag for gold mining

If prospectors want to use the device, they acquire or make a mini-dredge - an analogue of a large machine - reduced in weight and volume. Of course, the performance of such a device falls, but still, the method is more profitable than hiring people and manually washing it.

The essence of the device

In simple terms, a mini-dredge for gold mining is like a vacuum cleaner that sucks up earth with impurities, including metal particles. The weight of such a device is from 25 to 100 kilograms. Performance depends on the weight and parts that the minidrag is filled with. Common parts are:

• a system that ensures the buoyancy of the apparatus;
• the motor that starts the pump;
• injector;
• a chute for washing and separating gold from pacifiers;
• air supply system for underwater operation.

Before choosing a minidredge, you need to decide and decide on the advisability of constructing a device with your own hands. This can save a certain amount and make a device that will be designed for your needs. In order to design the device, you should pay attention to the components. There are several drawings that detail the steps involved in making a dredge. But some components still have to be bought to ensure a long service life.

The items purchased are:

• Engine. Any home-made dredge will not do without an engine, which you still need to buy, and not make it yourself. None of the prospectors are engaged in the manufacture of parts on their own. To save money, you can purchase a used engine, the main thing is to make sure that it has a hole for mounting the pump. There are special engine options for minidrags.
• The water pump is another part of the minidrag that is not crafted by hand. Choose the power and size of the pump in accordance with the engine and power. You can buy copies in craft shops.

All other parts of the minidrag can be constructed, but if you want the device to last for a long time, it is better to purchase a ready-made version. Hand dredge requires constant improvement, repair and refinement. It can take about six months to make the device.

The most fragile parts of the device are the hoses. They wear out quickly with constant use, so pay attention to the strength of the materials. But the gateway is the part that you can do yourself, but it is important to ensure that it captures and does not discard particles of gold.

The work of the minidragi consists of the following stages:

• Water entering the injector under high pressure.
• A further effect of the Venturi is to suck water and sand into the ground. All this falls into the washing chute.
• The engine starts the pump and the gold is filtered from the chute.

The efficiency of each device is different, but on average, processing rates fluctuate between 100 and 1000 kilograms of material per hour. If there are large stones at the bottom of the reservoir, they must be removed, as they will clog the minidredge. Therefore, sometimes during the extraction process, preliminary loosening of the bottom will be required.

A device such as a dredge is the most popular and most effective in gold mining. It improves over time and continues to gain popularity among miners. At the initial stages, you will have to spend money on the purchase or design of equipment, but in the future the acquisition will bear fruit.

Minidrag video:

Today we will talk about how to wash or mine gold yourself using a minidrag. We will also learn how to make a minidrag yourself for extracting gold from rivers and streams with your own hands from improvised materials. Consider assembly techniques, diagrams, drawings and photos of homemade mini dredges for washing gold

A standard home-made simplest mini-drag with a lower ejector, a bunker, pontoons, a frame with a motor / pump of about 2.5 hp has in the kit:

1. Bunker with a screen;
2. Gateway 25x90 cm;
3. Inflatable pontoons;
4. Frame;
5. Lower jet pump ejector;
6. Adjustable supports and fasteners;
7. Water intake suction hose;
8. 2" working hose 5 or 6m.;
9.Soft hose-sleeve 8m. for irrigation of the bunker;
10. High pressure hose 1.25” diameter 1.5m long
Dimensions of such a dredge: 130x60x40 cm.
fuel consumption 0.7 l/h
Productivity: from 1 to 1.5 m3/h.

Self-made minidredges of the suction type (dredgers) are known, containing a pontoon, a superstructure and a power plant. To facilitate the enrichment of soils, the latter are supplied with water through a floating pipeline to the shore.

Known devices are very inefficient due to the need to create pressure transport pulp; acquisition and operation of a floating pipeline; high costs for the storage of tailings from a stationary concentration plant.

The closest in terms of essential features is a mini-dredge with a capacity of 50 liters of scoops, containing a pontoon, a superstructure, a power plant, a screen, fine filling locks and a pebble tray. However, with a relatively high productivity, the dredge has a significant size for the development of small deposits, high metal and energy consumption, requires significant costs for installation and dismantling, and is difficult to operate.
The main objective of the invention is to create a mini-dredge, which allows to reduce the metal consumption, energy consumption and the cost of its installation, as well as to increase the efficiency of classification and disintegration of clayey sands.

To solve the problem, the mini-dredge, consisting of a pontoon, a superstructure, a power plant, a screen, fine filling locks and a pebble tray, additionally contains a deep filling lock located above the nose of the dredge in front of the grate mounted on the superstructure with the possibility of oscillation and rigidly connected with power plant.

The screen is equipped with removable grates of the grate type, and the lower edge of the upper grates is installed on the upper edge of the lower ones.

In relation to the prototype, the claimed invention contains the following features: the mini-dredge is additionally equipped with a deep filling sluice located above the bow of the dredge, in front of the grate screen, mounted on the superstructure with the possibility of oscillation and rigidly connected to the power plant. The screen is equipped with removable grates of the grate type, and the lower edge of the upper grates is installed on the upper edge of the lower ones.

Additional installation of a deep filling lock on the dredge above its bow in front of the grate reduces the length of the dredge and, accordingly, its metal consumption.

The screen, mounted on a superstructure with the possibility of oscillation, allows to increase the efficiency of classification and disintegration of metal sands due to the oscillation of the screen box.

Removable grates of the grate-type screen make it possible to carry out their periodic cleaning by one person without the use of special devices such as a crane-beam, which reduces the size and weight of the dredge and, accordingly, its metal consumption and specific energy consumption.

The arrangement of grates of the grate type along the pulp flow in such a way that the lower edge of the upper grates is installed on the upper edge of the lower ones provides effective unloading of the grates from large soil particles, which makes it possible to increase the efficiency of classification and disintegration of clayey sands.

The essence of the invention is illustrated in the drawing, which shows a General view of the mini-dredge in section.

The mini-dredge includes a pontoon 1 with a power plant 2, a soil intake device 3, a soil pump 4, which is connected by means of a pipe 5 to a deep filling lock 6 rigidly mounted on the superstructure 7 in front of the screen 8 with removable grates 9 of the grate type. The screen 8 is mounted on the superstructure 7 with the possibility of oscillation of the springs 10 and a rigid connection 11 with the power plant 3.

Directly under the screen 8 there is a distribution device 12 and fine filling locks 13, and at the end there is a pebble tray 14 and a stacker 15.

The mini-dredge works as follows: soil deposits with useful components are loosened by an excavation device of a rotary or milling type and enter the soil intake device 3 due to the operation of a soil pump 4 driven by a power plant 2 (electric motor or diesel engine). Water with soil deposits (pulp) exits under pressure from the soil pump 4 and enters the deep filling lock 6 through the pressure pipe 5, where large grains of useful components are captured.

Next, the pulp enters the screen 8 on removable grates 9 of the grate type, where the classification of soil deposits by size occurs, and the screening efficiency is also ensured by vibrations of the screen box under the action of the vibration of the power plant 2 and the soil pump 4 due to the installation of the box on the superstructure 7 using the spring 10 and a rigid connection with the power plant 2. Then, with the content of soil particles, it enters the distribution device 12, after which it enters the fine filling locks 13 to trap fine grains of the useful component. Large soil particles from the screen enter the pebble tray 14 and are removed by the stacker 15 to the pebble dumps.

Thus, the proposed mini-dredge, in comparison with the prototype, allows to reduce its metal consumption by 2.5-3 times, specific energy consumption, as well as the costs and time for installation (dismantling) of the dredge from 250 to 2 days.

Many miners would like to have such a wonderful gold mining device as their own suction dredger, but the prices for this equipment are unfortunately high. However, do not forget that at the dawn of dredging, there were no factories producing dredges at all, and these small devices were assembled by hand in some garage. So if you do it yourself, you will save a lot of money, just like I did.

Of course, you will use all the cheapest, but do not count too much on the fact that you will get by with a symbolic amount. No one wants everything in their dredge to wobble, fall apart, or not work. The device must be functional, reliable and durable. You will not waste time thinking about your project and deciding what and how to do. Think about what exactly you want to get in the end and what you need, weigh everything together and decide what you can afford. Make charts and lists. Perhaps the best thing I can advise you in this case is to study the design of devices from such well-known brands as Keene and Pro-line. These companies have done extensive research on their equipment, tested various settings, and improved the components of their dredges so that they work perfectly.

By visiting the websites of the above companies, you will find excellent photos of these devices, view information about the components from which they are made. If your nearest artisan shop sells ready-made dredges, study them carefully, perhaps even take some measurements and, if possible, photograph them. Another great opportunity is to join a mining club whose members are active in dredging. It won't hurt you if you watch them work. Members of such a club may even let you take care of the dredge yourself. The more general knowledge you have about dredging, the better your design will be.

If you find a junkyard or recycling plant, then there you can get some important parts at the lowest prices. I advise you to take a list of necessary components and materials and visit such a place with it. You can even find the right engine for your dredge there.

When you finally get your hands on your own dredge, the first question that comes up will probably be how big you want to build it. The larger the dredge, the more soil it can process, but the greater its weight and cost. Between these values, you must find a compromise, focusing on the amount of material being processed and the possible depth at which you will be dredging.
Another thing to think about is that you are better off building a dredge with a hose diameter of 10 - 12 centimeters, that is, it should be of such a size that you alone can handle it. Although, if you are a young tall strongman, you may be able to carry away a 14 cm device, but this will take a lot of time and effort. 10 centimeters is probably the best size for equipment operated by one person.

Do you need compressed air for diving? Then you will need an air compressor, an air intake tank, as well as diving equipment. Air is a really handy thing, but it's not necessary at all: you can always do it later if your project is good and you're planning on installing a compressor on your dredge.

To build your dredge, you will need an engine and a pump, as well as various tools, such as a hacksaw, riveting hammer, screwdrivers, wrenches, etc. The more experience you have in this kind of work, the better your dredge will come out. Knowing how to use a welding machine is also very important, as my little 120 volt welder helped me solve some pretty tricky problems during the assembly process. If you do not have such a device, then this is another reason to buy it! I strongly advise you to have a welding machine.

Pay close attention to the price of the parts and figure out what you can afford: you can certainly save a lot of money building your own dredge, but it still comes at a cost. I strongly recommend that you calculate the estimated costs before you start buying the necessary components. Make sure you have enough money for everything. As for me, I decided to buy some parts from Keene, because I don't think I can make them any better than Keene. On the other hand, I also bought some used components.

Everything I used to build my 10cm dredge cost about a third of what you would buy a new one for.

Almost impossible to make yourself (but you can buy used)

Engine

I've seen really good homemade dredges, but no one has also put homemade engines on them. You can buy a used motor and save some money, but no one makes this part themselves. Make sure your engine has the necessary holes to attach the pump to it. Select its size according to the size of the pump. Manufacturers use specific sizes for these components, as well as the size of the hose used. Focus on them.

Water pump

Like I said, I've seen really great homemade suction dredgers, but then again, no one has put homemade pumps on them. The centrifugal pump used by all dredge manufacturers is the best choice. I recommend that you purchase a pump from Keene. I bought mine already used in a local artisan shop. Do not use a slurry pump: the large volume of sand and gravel that will flow through it will quickly disable this part. They are also quite heavy and will require more power from the motor.

Air compressor

I have a compressed air pump but I didn't install it on my dredge. I have been dredging for many years, but have never used anything other than a snorkel, although of course this imposes its own limitations on the choice of reservoirs for work. In this case, if you have long arms, you are a real lucky one. If you do have a compressor, make sure it can be attached to the motor. Do not use pumps and hoses that are not designed to produce breathing air.

There are many options when choosing a hose, but be careful: the thin and fragile materials from which this part can be made will wear out quickly. The transparency of the hose is also important - you can see where it is clogged. The materials used by dredging manufacturers are excellent: they are reliable and will allow successful dredging.

Ore washing chute (lock)

The gateway is probably the biggest and most important thing you can do on your own. This is a key and crucial detail - if your gateway doesn't capture the gold, the whole project will go down the drain.

For many years I have used a homemade 4" dredge in various fields in California. In order for the device to suck in more rock, some time ago I replaced the old pump with a new, more powerful one. However, as I continued to work, I noticed a decrease in the proportion of mined fine gold. I knew that old-fashioned sluices weren't very good at capturing small metal particles, and increasing the amount of material fed further reduced the recovery percentage.

One day in 2002, while working on a dredge, I noticed a small nugget go too far down the lock, almost falling out of it. Its weight was 8 grains. Thus, I realized that I need to do something so that the gold is not lost in the process. I began to think about this problem. Driven mainly by high prices, I decided to build my own gateway. I didn't have a specific plan or blueprint, but as a mining engineer by training, I have access to the equipment I need, so my project didn't seem out of the question.
The device of almost all portable gateways is based on the so-called "Hungarian" stencil, which I wanted to install myself.

The idea of ​​the “Hungarian” (also called LazyL) stencil is as follows: water and rock flow along the stencil, and a small waterfall forms behind each of its thresholds. Light particles pass on, while heavy ones, such as gold, are deposited. There is nothing technically complicated here: the thresholds are made from a piece of steel. All this can be done on your own. Such steel thresholds are much more effective than any other. While contemplating my own gateway, I carefully examined similar equipment at a nearby artisanal store, and also visited the GPAA Gold Prospectors exhibition, where I paid special attention to Keene's gateways.

I decided that a lock equipped with such a stencil is the best choice for me and with such a device I will extract all the fine gold that is possible. This is the design Keene uses on their latest drag models. But first, I had to get a bell (a device for supplying rock to the lock). However, it is very difficult to make it, so I purchased a bell from Keene. They are made of molded plastic, and this is the main reason to buy rather than make it yourself. When I bought a bell for my project, I figured it would work on a 16" (40 cm) wide sluice.

My old airlock was 53 inches long and the new one had to fit into the existing frame (I didn't want to remake it). I spent a couple of days walking around the junkyards looking for something useful. My entire project was partly based on what I already knew about the operation of such equipment, partly on what I saw in commercial samples, and partly on what I could find in junkyards or what lay in my garage.

The more time you spend thinking about the design of your future homemade gateway, the better. Of course, I don’t really want to buy some extra parts, but at the same time, the device must be effective. A good work plan and understanding of the gold mining process itself is very important. Mining moss, which is not used on commercial equipment, is in my opinion a very important detail in the design of a lock. I routed it under all the thresholds of my device.

In a three-section lock, most of the gold is collected at the top. As the pebbles pass further, they hit the screen, with 5mm holes (on my sluice). Then, the remaining pebbles and the smallest gold passes to the bottom of the lock. There, the slower water velocity allows fine metal particles to settle. Material larger than the openings on the screen goes into an additional section of thresholds before finally exiting the lock. This is a common device of similar equipment.

I borrowed metal shears and a press brake from a friend of mine. I cut the steel into strips and bent them into thresholds. They looked like standard Keene airlock parts modified in the Hungarian way. To make the sills, I secured the edge of the strip of steel about a quarter of an inch, and bent the rest at a 45 degree angle. If you have a press brake, then doing all this is not at all a problem. Thresholds of the upper section are 18 mm high, the next section are 30 mm high and the lower section are 9 mm high. I used standard 1.5mm thick mild steel for all sections. The airlock itself is a large piece of bent aluminum. You can make it in two hours.

A project like mine requires special tools such as metal shears, a press brake, and welding equipment. It is impossible to do without it. Once you've cut and bent the steel the way you want it, the next step is to weld everything. In order to mount the thresholds, welding is also required. There is nothing difficult in this. I'm not the best welder, however, and I managed to make everything solid and reliable.

In order to secure the flat strips of steel in place, they are welded at the ends of the thresholds. The straight part of the threshold is welded at a right angle to the bottom of the gateway, and the bent part at an angle of 45 degrees.

For people with the right tools and some metalworking skills, making a lock like this is not the most difficult thing. I spent about 10 hours on all this. Much more time was spent on planning and designing the gateway.

floating frame modification

In order to use the frame I already had, I had to upgrade it a little, namely to raise the engine a couple of inches and adjust the bell running from below. My frame has tubes from truck tires.

The frame itself is quite wide, but there is no difficulty in trimming it if necessary.

Exploitation

At the first start, I noticed a big difference between the operation of my new gateway and the old one. The light water on it no longer foamed, but flowed very well and correctly. At the first cleaning, I found that fine gold is much better extracted. In general, the gateway did what was required of it. I've never had a problem with section overloading, although those who use Keene equipment do. I lengthened the section that had the 3/8" thresholds a bit and noticed that there was not enough slope and the water was carrying large pieces of pebbles. After I removed this detail, it seemed to me that the device still continued to work remarkably, although, perhaps, with the missing section, the recovery would have increased. Next year I'll shorten it a bit and try again.

Job Report

When I cleaned the lower sections of the rapids, I noticed that along with the "black" sand, there was only fine gold left. According to Keene's ad, 90 percent of the visible gold in their equipment is deposited on the first section, which means that my gateway works about the same. A small amount of gold ended up outside the thresholds of the upper section, so I placed a miner's moss there. The first cleanup showed a significant increase in gold recovery. Even more than I expected.

In my opinion, the main thing to do to improve recovery is to get rid of the junction box. The bell slows down the flow and spreads the material, thus increasing the extraction rate. Just compare all the clear water bubbling and foaming in the box of my old lock with the operation of the new version of this equipment.

The design of the airlock held up well, only once a piece of welding broke during operation, which, however, did not affect the functioning in any way.

For those who are interested in making their own gateway, I can say that with the skills of working with metal, it is quite easy to do. If you are making a gateway, the material into which must be fed with a shovel, then, in this case, the design of the device will be even simpler.

Building a homemade gold mining lock is, in my opinion, a great start for a beginner. It's just worth carefully studying commercial copies, and then developing your own project.

On the other hand, if you are making a dredge sluice, I recommend making it a two-level one. They install Keene and Proline on the latest models of their dredges. I don't have blueprints ready, but you can draw them yourself, it's not difficult, just look at your friend's gateway or the one they sell at the nearest artisanal shop. Be sure to use miner's moss, placing it under the rapids. This detail will significantly increase the ability to "catch" gold.

Here is my cost estimate for building the gateway:

Pieces of aluminum $10

Pieces of iron $5

Paint $4

Prospector Moss $56

Welding rods $8

Total $83.

I think a new dredge lock of the same size would cost over $500. The funny thing is that I spent most of the money on miners' moss. I actually think it improves gold recovery. This is perhaps the second most important detail after the bell, which increases the extraction of fine gold.

The remaining elements of the dredge are described below.

Bell (water collector, junction box)

It is installed in the head of the lock and serves to direct the flow of water and soil into it. Here you need to decide. You can make it quite easily. Personally, I spent money and bought this part all in the same Keene company.

It is quite difficult to make it, but if you have welding skills, then it is possible. First you need to determine whether you will be using a suction nozzle or a suction nozzle on your dredge.

The suction tip (nozzle) has been used since the first jet dredges. Its essence lies in the fact that the suction device (hydraulic elevator) is placed at the end of the supply hose (Fig. 2). In this case, a jet of water from the pump is fed to its beginning through a nozzle and a vacuum is created here. The main disadvantage of this scheme is the need to have two long hoses, one from the pump to the nozzle, and the other to supply the rock. It is difficult to control the suction handpiece with two hoses attached to it, especially on large dredges. Therefore, the tip is used only on small dredges when working in shallow water. The suction tip works more reliably in shallow water than the nozzle.

The suction nozzle is distinguished by the fact that the device that creates a vacuum is adjacent directly to the receiving box of the flushing sluice. In addition to more convenient handling of the suction hose during excavation, this design has a number of other advantages. Given the proximity of the location of the power unit (engine and pump) from the nozzle, it becomes possible to install two, three or more pumps with separate nozzles, which significantly increases the productivity of the dredge with the same diameter of the suction hose.

In addition, the short length of the pump hose to the nozzle leads to significant pressure stabilization, and, consequently, to greater stability of the entire system as a whole. At the same time, when working in shallow water, air can enter the suction hose, and the rock supply stops until the hose is completely filled with water. Therefore, in shallow water, a nozzle is less effective and a suction nozzle is preferable.

Buoyancy

At this stage of creating a dredge, you can save very well. You can ensure the buoyancy of your apparatus in a variety of ways. At the very beginning of the history of the use of dredges, large tires from trucks were used for this purpose, which weigh a little and are inexpensive. This is the option I chose for my own model, but I quickly found that getting these tires was getting harder and harder.

Today, most drag manufacturers install plastic pontoons. They are more reliable, but at the same time, and heavier. There are many options here too. On some dredges assembled at home, I saw a variety of types of such plastic pontoons. An interesting way is to use plastic containers or barrels (with a capacity of 20 - 40 liters). They can be bought quite cheaply. Of course, you can also buy pontoons from a specialized drag manufacturer, but this will cost a pretty penny.

Another important part of the buoyancy system is the frame on which the trough and motor are mounted. I made it from pieces of aluminum found in a landfill. All this was very cheap and did not require much effort. Since the frame was flat, I easily attached truck tires to it.

Checking the operation of the dredge

After you have found all the necessary parts and assembled the dredge, it's time to check how it works. To do this, take a couple of dozen small pieces of lead, flatten them and paint them with a bright paint, such as red. In the nearest reservoir, collect soil and place lead there. Try your dredge on this soil, washing the rock, removing the concentrate from the lock and counting how many pieces of metal you have extracted. Losses should be no more than 1-2 pieces. If, unfortunately, it happens that the chute is missing more lead than stated above, you need to adjust the dredge, make the necessary improvements, until you are sure that it will work well.

Finally, you will need a specific type of diving suit, depending on where you will be using the dredge. Even in California in the middle of summer, after two hours in the water, it gets damn cold, so this protection is a must.

Most of the previously explored gold deposits along rivers and streams, especially in the pre-revolutionary period, are now abandoned and have not been developed for a long time, but in vain. In fact, their potential is far from exhausted.

In those distant times, however, compared with modern methods, the technique of gold mining was primitive and more than 50% of gold remained in dumps or simply was not found. If today you go through an old mine even with an ordinary metal detector or a mini-dredge, then on the first day you can collect a decent gold "harvest"

You just need to know where such an abandoned mine or gold deposit is located. Old pre-revolutionary maps of gold deposits, detailed geological and topographic maps of exploration of gold ores, veins and placers can help with this. As a rule, such cards are not freely available. They can be found in regional archives or major libraries.

Gold has been mined since ancient times. For the entire period while this activity is carried out in the world, the scale of production of this noble metal is equal, approximately 170 tons. Half of the mined gold goes to the production of jewelry, which has a fairly high cost. According to the calculations of scientists, if all the mined gold is collected in one place, then it is possible to form a solid cube with a height of a 9-story building with a 20-meter edge.

World gold mining

Nowadays, gold mining is not an exciting adventure that ruins some people and makes others rich. Now, this activity has become an actively developing type of income.

Enterprises that are engaged in industrial gold mining, keep accounting records, calculate economic feasibility, conduct geological exploration using modern technologies. That is, it is the provision of a workplace for many people with different professions.

World gold mining is made up of dozens of countries, and the Russian Federation is no exception. Gold nuggets are rarely found here on the surface of the earth, however, at some depth underground, there are so many gold deposits that it has allowed the Russian Federation to take the fourth place in obtaining this noble metal in the world. Today, Russia holds 7% of the world's gold reserves.

The absolute leader in gold mining since the early eighties is the Republic of South Africa, which provides about 70% of all gold production. Although, in the early nineties, South Africa's income fell by 35% due to a decrease in exploration of new gold deposits. And some states, such as Australia, on the contrary, began to develop underground and surface gold placers located on its territory more.

Methods of gold mining in Russia

Over time, gold mining methods have been constantly improved and changed. Initially, manual gold mining by sifting sand in water was widely used.

Then people mastered the extraction of noble metal from ore. These days, manual gold mining is a rarity. Basically, this process is automated, but this does not make it easier. After all, in order to find a profitable field, you need to spend a lot of effort and money. A payback deposit is one in which 1 ton of soil accounts for 3 grams of pure gold.

More recently, in the gold mining industry, a method such as amalgamation has been popular. Its peculiarity lies in the use for, placed at the bottom of the container. The barrel was filled with gold-bearing ore and shaken. As a result, the gold particles remained in the mercury at the bottom of the barrel. The main negative quality of this method is the high toxicity of mercury.

Today, gold is separated from the ore using sodium cyanide. Thanks to the emergence of this method, it became possible to extract gold from previously abandoned deposits, which returns their profitability.

Gold is also mined with the help of dredges - floating mining machines equipped with everything necessary to extract metal from the ground. The dredge works only on terrain with a certain soil. This should be a watery area, so often such special vehicles are installed near river banks or other bodies of water.

What is a drag?

A dredge is a device that is directly related to gold mining. The weight of this device reaches several hundred tons. This is a mechanized unit equipped with buckets operating on the principle of a chain excavator. On board the floating platform there is everything you need to wash the rock and sand. A large dredge can be controlled by a crew of up to 10 people, while a small special vehicle needs only one manager.

At the cost of a dredge for gold mining, it is available only to large enterprises. Before installing this machine, you need to remember that this idea may not be profitable when the content of the precious metal in the soil is low.

Therefore, before using this special machine, it is necessary to carry out a number of reconnaissance activities, including geological research and chemical analysis of the composition of the soil to determine the concentration of the noble metal in it. Only in this case, the profitability of industrial gold mining will be justified. In addition, it takes a lot of effort and time to install a dredge, since the machine is quite heavy and overall.

Drag classification

Dredges are grouped:

• by the type of energy required for the operation of the apparatus: electricity, energy from the combustion of gasoline or diesel fuel vapors;
• by the depth of work with rocks below the water level: shallow, deep water;
• by bucket capacity: small, medium, large-capacity;
• according to the method of maneuvering: rope-pile, rope-anchor.

As a rule, two types of special vehicles are used for gold mining:

• marine;
• continental.

These types of drags differ in that the marine special vehicle is similar to a ship that can be moved along the coast, while the continental one requires more resources, as it is mounted on a pontoon.

Smaller special vehicles called mini-dredges are ideal for individual gold miners or prospectors. You can either buy them in specialty stores or make your own. The mini-dredge has been significantly reduced in size. Its weight characteristic ranges from 25 to 100 kg.

A positive feature of the use of mini-dredges is to reduce labor costs and speed up the process of gold mining. Therefore, the interest of miners in the construction of the unit with their own hands at home is justified.

The principle of operation of the dredge

Externally, the mini-dredge looks like a vacuum cleaner that sucks up sand with gold dust in order to separate one from the other. All possible models of these special vehicles differ in size and materials from which they are assembled, but their structural elements are similar:

• a system that provides buoyancy of the device;
• a drive responsible for the operation of a centrifugal pump;
• injector;
• washing trough for separating precious metal from slag;
• air supply system for breathing under water.

The extraction of metal by a mini-dredge is divided into 3 stages:

• injection under high pressure of water into the injector chamber;
• then water with sand and earth is sent to the washing trough to separate the precious metal from the slag;
• the drive starts the pump to weed out the gold in the chute.

The performance indicator for all devices is different, but on average it stays in the range from 100 to 1000 kilograms of processed rock per hour. Before you start working with a mini-dredge, you need to clear the bottom of the reservoir from stones, because they can clog the unit.

The miniature gold mining dredge is an efficient and popular gold mining machine. It has been modernized over time and is becoming more and more popular among miners. At first, you need to seriously invest in the purchase or assembly of the device, but then this investment will bring considerable profit.

Before collecting homemade mini-dredges, you need to know that gold mining is not prohibited on the territory of the Russian Federation. Along with this, artisanal mining of this noble metal is close to crime.

Video: Gold mining on a dredge