Dredge - special equipment for gold mining

In the modern gold mining industry, two methods of obtaining precious metals are actively used. The first method is called hydraulic; it consists of washing gold out of the rock under the influence of a stream of water supplied under high pressure. However, the second method, based on the use of a special machine, is much more effective.

A dredge for gold mining is a huge device the size of a 4-story building and a weight that reaches 1,400 tons. The unit operates afloat, its design includes a whole complex of scoops that lift rock from the bottom of the reservoir, and from this rock by washing get gold ore.

The wide functionality of the dredge allows you to perform the entire range of tasks for the development of placer deposits, starting with the extraction of rock and its delivery to the washing site and ending with waste disposal.

To operate this colossus, the simultaneous efforts of 9 people are required, but the productivity of the device is simply amazing, it is equal to the efforts of 12 thousand miners, “armed” with primitive trays.

Types of dredges for gold mining and principles of their operation

The units that became the topic of our conversation come in two types: continental and marine. The design of both types is almost the same: a floating vessel, masts, equipment for scooping rock, a device for maneuvers, equipment for enrichment. The main difference lies perhaps in the absence of stalkers and piles in marine dredge models.

Continental dredge models are used to study and develop deposits on the mainland adjacent to a body of water. Such devices are based on pontoons. Marine models are used for gold mining, as well as for the extraction of all kinds of minerals and diamonds. Similar equipment is installed on ships, not only on towed ones, but also on self-propelled ones.

Important
Mini-dredges for gold mining have become very popular today.

In appearance, the device resembles a vacuum cleaner that sucks up sand mixed with ore and then separates it. The weight of such equipment varies from 24 to 90 kg, design features may be different, the following components and assemblies are the same:

system providing buoyancy;
a motor that drives a centrifugal pump;
a chute designed for washing and separating rock;
injector;
air supply system (only on some models).

Speaking about the principle of operation of a dredge for gold mining, it is necessary to mention the following: a stream of water under enormous pressure is supplied to the injector. Rock (pebbles, sand, etc.) is drawn into it along with water and directed to the grid of the rinsing chute. The motor drives a pump that helps sift the gold from sand and debris.

Operating principle of the dredge

Externally, the mini-dredge looks like a vacuum cleaner that sucks up sand and 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:

One type of mini dredge

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

Metal extraction using a mini-dredge is divided into 3 stages:

Mini dredge gold mining scheme

pumping water under high pressure into the injector chamber;
then water with sand and earth is sent to the washing trench to separate the noble metal from the slag;
the drive starts the pump to sift out the gold in the trough.

The performance indicator for all devices is different, but on average it ranges 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.

Mini-drag Afalina 1000

A miniature gold dredge is an effective and popular unit for gold mining. It is modernized over time and becomes more and more popular in prospecting circles. First, you need to seriously invest in the purchase or assembly of the device, but then this investment will bring considerable profit.

Before assembling homemade mini-dredges, you need to know that gold mining without a license is prohibited in the Russian Federation. Along with this, artisanal mining of this precious metal is close to crime.

How to pan or mine gold using a dredge

Before using a dredge for gold mining on rivers, a company or enterprise must collect a whole package of documentation and take care of obtaining the appropriate license. In this case, management must comply with a number of requirements:

first of all - to conduct geological exploration;
perform an analysis of the quality of the material, perform detailed calculations;
prepare detailed designs for the development of future fields;
take care of obtaining an allotment (land and/or mining).

If we are talking about using, for example, a mini-dredge on a private basis, it should be remembered that such activity is illegal and is prosecuted in accordance with the current regulatory framework.
True, this is not an obstacle for many of our compatriots - such a complex, full of adventurism, but, nevertheless, very profitable in some cases, the fishery enjoys considerable popularity in some regions of our state.

What is a dredge?

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 rock and sand. A large dredge can be controlled by a crew of up to 10 people, while a small special vehicle requires only one manager.

Dredge design diagram

The cost of dredging for gold mining is available only to large enterprises. Before installing this machine, you need to remember that this idea may be unprofitable if the content of precious metals in the soil is low.

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

How to mine gold sand by dredging

The process of washing sand with a dredge:

The soil, which potentially contains particles of precious metal, is placed in the receiving hole.
The installation washes the soil, removing excess fractions from it. The latest models of profile equipment are equipped with an automatic flushing function for coarse rock, which eliminates the risk of damage to the device.
The washed soil is fed into a drum, where it is wetted and crushed into smaller parts.
The next stage is that the soil is sent to the enrichment sluice, and then the remaining raw materials, which are guaranteed to contain nothing valuable, are thrown back.

The functionality of the dredge for sand extraction provides the ability to make individual settings, in particular:

intensity of rock cleaning;
fuel consumption;
drum rotation speed;
cleaning method (depending on soil type).

Dredge cost: current offers

We analyzed the proposals on thematic Internet resources and came to the conclusion that the cost of industrial installations is negotiated on an individual basis.

Important
On the website of manufacturers of such equipment, after a detailed description of the models available for purchase, there is a message that to clarify the price you need to contact the seller.

For example, one of the sites we studied presents a wide range of Julong industrial dredges. The seller offers consumers a wide variety of models - amphibious self-propelled crawlers, mine, bucket, jet suction dredges, portable and stationary installations - the choice is huge, however, in the “Price” column, “Negotiable” is indicated everywhere.

As for options for private use, the situation here is as follows:

Mini dredge Keene 4500 RN from a reputable American manufacturer, Engineering, costs 450 thousand rubles. The seller, according to the data presented on the website, is located in Krasnoyarsk.
The Russian-made mini-drag “Nugget-50” costs 139,400 rubles and is sold in the city of Bratsk. A less powerful model from the same manufacturer, “Nugget-40,” costs much less – 75 thousand rubles. All the models we mentioned, according to the seller, are new and are covered by a factory warranty.

Gold mining. Methods of gold mining. Mining gold by hand

Gold mining began in ancient times. Over the entire history of the earth's population, approximately 168.9 thousand tons of generous metal were mined, almost 50% of which is used for various jewelry. If all the mined gold were collected in one place, a cube would be formed the height of a 5-story building, with an edge of 20 meters.

"Golden Story"

Gold is a metal that the world's population became familiar with at least 6,500 years ago. The oldest treasure is considered to be found in the Varna necropolis, which is located in Bulgaria, and the items are dated back to 4600 BC.

Gold has played an important role throughout the history of the world's population, and it is still considered a reliable financial investment. Currencies have come and gone, but it has remained a universal and measured pattern for thousands of years.

Possessing this metal has always been prestigious. Not only wealth was assessed by the amount of gold, but position in society also depended on it. This is still the case today.

note

Specifically, gold was often a prerequisite for wars and atrocities, but it immediately played a gigantic role in the progress of the world's population in general.

On its basis, a monetary system began to take shape, cultural values and construction masterpieces were created, which are priceless and still amaze everyone to this day.

Thanks to the zeal to produce this metal, scientists obtained many chemical elements, and gold rushes helped to discover and develop new lands.

How gold is mined in Russia

In the upper crust of the earth, gold is contained in small quantities, but there are quite a lot of such deposits and areas. Our homeland is in 4th place in the ranking for its production and has 7% of the world share.

Gold began to be mined using the factory method in 1745. The first mine was discovered by the peasant Erofey Markov, who told about its location. Then they began to call him Berezovsky.

Today in Russia there are 16 companies that mine this precious metal. The favorite is , which has 1/5 of the entire production market. Diligent artels mainly mine metal in the Magadan, Irkutsk and Amur regions, Chukotka, Krasnoyarsk and Khabarovsk territories.

Gold mining is a difficult, labor-intensive and expensive process. Such costs are reduced by closing low-income and unprofitable mines. Reducing the volume of geological exploration and introducing new technologies that save capital are completely effective measures.

Gold mining process

As centuries passed, the process of mining this metal was constantly changing. At first, manual gold mining was popular. Miners obtained gold dust thanks to simple, simple devices.

They collected river sand into a tray, and then shook it in a stream of water, the sand was washed away, and the grains of metal remained on the bottom, because they were more languid. This method is often used today.

Important

But this is not the only extraction process. For example, previously gold nuggets could often be found along rivers. They were thrown onto land during the erosion of gold-bearing veins by a natural method. But by the 20th century there were no rich placers left, and they learned to extract gold from ore.

At the moment, manual gold mining is rarely practiced; the process is one hundred percent mechanized, but at the same time it is very difficult. A deposit that contains 3 g of gold per ton is considered profitable. At 10g it is considered rich.

Methods for extracting gold from ore

A couple of years ago, a method such as amalgamation was often used, which is based on the special property of mercury to entwine gold. Mercury was placed at the bottom of the barrel, then the gold-bearing rock was shaken in it. As a result, even the smallest particles of gold simply stuck to it.

After that, the mercury was separated from the gangue rock, and with strong heating, the gold flaked off. But this method also has disadvantages, because mercury itself is very toxic.

With all this, it still does not produce 100% gold, because the very tiny particles of the precious metal are poorly wetted.

The second method is more modern - gold is leached with sodium cyanide, which can convert even the smallest particles into water-soluble cyanide compounds. And from them later, with the help of reagents, gold is extracted. With this method, it is possible to obtain precious metal even from already abandoned deposits, which makes them profitable again.

Getting gold at home

Manual gold mining is also possible at home. In order to extract it, you don’t have to go to the mines and shake trays for hours. There are more measured and civilized ways. There are a lot of objects around that contain gold. For example, old Russian watches in their yellowish cases contained real, pure precious metal without impurities.

In order to get it from there, you just need to buy such watches in very large quantities. Then you will need a plastic bucket and basin, an electric stove, razor blades, a heat-resistant glass pan, a brush and a cotton cloth for filtering, rubber gloves and a spray bottle. The required chemicals are nitric and hydrochloric acids.

Recycling begins when you already have 300 cases on hand. The process will take only 4 hours, and you will use 4 liters of acid. From this number of cases you can get 75 grams of untarnished gold.

Obtaining gold using the etching method

Who could think of it, but everyone, even kids, carries gold in their pockets and bags once a day. Everything is very simple - any SIM card for a mobile phone contains a certain amount of precious metal. It can be extracted from there too. This is done using 2 methods: electrolysis or etching. For the latter you need the chemical reagent “royal vodka”.

The most common method is specifically etching, in which gold is obtained due to the chemical inertness of the precious metal, and specifically, its ability to react with other elements. For etching you will need the oxidizing agent “royal vodka”, which is made from concentrated acids: hydrochloric and nitric. The liquid is orange-yellow in color.

Gold from water

Gold can also be mined from water. It is also contained in it, and in any kind: sewer, sea, water supply, but in very small quantities. For example, in the sea it exists in a proportion of 4 mg per ton. Despite this, it can still be extracted using quicklime, which will require only a ton per 4.5 thousand tons of water.

In order to obtain gold from sea water, you will need to mix it with milk of lime. After some time, the liquid must be released back into the sea, and the precious metal must be extracted from the sediment. Kirov engineers propose another waste-free method in which lime is replaced with ash from thermal power plants. This method is considered the least expensive of all the recognized ones.

Golden bacteria

In Canada, scientists actually found bacteria that are capable of releasing gold from different mixtures.

Mind-blowing, isn't it? For example, the amoeba Delftia acidovorans has a substance that releases precious metal from solution.

Advice

And the reason is ordinary - she simply defends herself, protecting herself from gold ions, which are toxic to her. The second amoeba, Cupriavidus metallidurans, on the contrary, accumulates it in itself.

Both were found in 2006 in “gold” mines. Canadian research has shown that microbes that accumulate gold manage to avoid poisoning due to their genetic nature.

Draghi

Gold mining is also done using dredges. They are called floating mining machines that have dredging, processing or other equipment that provides comprehensive mechanization of the mining process. They enrich minerals and remove waste rocks.

The purpose of dredges is to develop watered deposits of the necessary minerals and extract valuable components (gold, platinum, tin, etc.) They are used mainly in alluvial, deluvial, deep- and coastal-marine sedimentary and placer deposits. The only exceptions are bouldery, strong rocks and viscous clays.

Types of dredges

Dredges are divided into two classes.

Offshore, with the help of which deposits in the coastal zone and deep mines in lakes and oceans are developed. They are installed on towed or self-propelled keel vessels, which ensure operation in storms.
Continental, which are used to develop deposits on continents. Installed on a flat bottom boat.

Dredges are systematized by:

the type of energy that drive mechanisms use;
deep excavations of rocks in the section below the water level;
type of apparatus (many scoops with an interrupted chain, with a continuous chain, a rotary complex, a dragline bucket, a clamshell bucket);
scoop capacities (large, medium and small);
maneuvering method (rope-anchor and rope-pile).

In the Russian Federation, dredges are currently used to extract gold, mainly in the Far Eastern federal region. But mining in this way can have a bad impact on the ecosystem, damage river landscapes, and greatly pollute the area located downstream.

Therefore, this method can only be used with careful adherence to development projects. To implement them, it will be necessary to reclaim lands that have been disturbed by mining operations, as well as restore forests, land and vegetation of river valleys.

How to make a dredge for gold mining without the help of others

Many gold miners would like to have their own dredge, while at the same time saving significantly on costs, because the prices for this equipment are very high. In this case, the easiest way is to do it yourself. Despite the fact that the cheapest materials will be purchased, a certain amount will still be needed to create the dredge.

First, you need to make lists and assembly diagrams; for this you can take as an example the most famous dredges for gold mining today. Basically, the first step is research, the more you know about them, the better and better you will make yours.

Some important parts can be found in a regular landfill, and you can buy them cheaply, for example, an engine for a device. Next, you need to decide on the size of the dredge; the larger it is, the greater the amount of soil that can be processed, but its weight and price will also be higher than that of a small assembled product.

It must be built with a hose diameter of up to 12 cm, so that you can deal with the dredge without the help of others. The best size is 10 cm. If you need compressed air, you need to purchase an air compressor, diving equipment and an air intake tank. But this is not the first need; this can be done later.

In order to build the desired apparatus, you will need: an engine with a pump, various tools (a hacksaw, a hammer, wrenches, screwdrivers). It doesn't hurt to buy a welding machine. You can take used parts, but for some that are particularly important and problematic or difficult to replace, it is better to purchase new ones in the store.

It is often impossible to make some dredge parts yourself, so you still have to purchase them: an engine, a water pump, an air compressor, a hose, an ore-washing chute. It is the latter that is the most important detail; without it, gold simply is not captured, and accordingly, the entire constructed apparatus loses its meaning.

The dredge bell should be installed at the head of the sluice so that it directs flows of water and soil into it. The absorption valve confiscates water into the pump (this is also one of the important details). If sand is sucked in, the pump can quickly break down, so you can’t dredge without a valve.

note

The hydraulic elevator is located at the end of the hose, while water is supplied to the beginning and a vacuum is created. It is best to use a suction nozzle here. It is difficult to operate an elevator on huge dredges, so it is mainly used on small machines if the work takes place in shallow water.

The buoyancy of the apparatus is a separate step in the creation of the dredge. This can be achieved in several ways. At first, we used tires from trucks; they weigh little and are inexpensive. The only obstacle is that getting them is not as easy as it might seem. But it would be a balanced option.

At the moment, many dredge manufacturers use plastic pontoons. They are quite reliable, and also languid. Still, there are a huge number of options here. Some dredges that are assembled at home have different plastic pontoons.

One of the interesting methods is when they use plastic containers or barrels with a capacity of up to 40 liters. You can buy them quite cheaply.

If you don’t mind spending a huge amount, but purchasing something ready-made, then it’s easier to purchase from the manufacturer.

Another important detail that affects buoyancy is the frame. It is on this that the motor and the ore washing chute are attached. If you do it without the help of others, you can take ordinary pieces of aluminum, which can easily be found in any landfill. It will be cheap and require virtually no effort. If the frame turns out to be flat, then truck tires are simply attached to it.

You can check the operation of the dredge after it is completely assembled. To do this, take two dozen small pieces of lead, which are leveled and painted in a catchy color. Soil is collected in the reservoir and they are placed there. Oh, so you can try the dredge on it.

Look how many pieces of lead came back after washing the rock. During normal dredge operation, losses are likely to be only up to 2 pieces. If there is not enough lead, then the entire assembly should be checked again according to the diagram, and if necessary, additional improvements should be made.

Future gold mining plans

There are fewer gold deposits, they are currently being discovered mainly in South Africa, others are being significantly depleted, and deposits with low and medium contents of the precious metal are simply unprofitable to develop.

According to professional forecasts, the reserves of the necessary minerals, which contain gold, can be developed for another 50 years. Later they will be exhausted.

It’s simply because the world’s population has been very active in gold mining in recent decades. And it becomes less and less in nature.

Important

Now we have to find new ways of extracting this metal in the coming years. The most promising method is considered to be gold leaching technology.

In recent years, there has been a lot of talk about ocean mining as another method of extracting gold. There are a lot of sea placers and deposits, but the bottom has not yet been fully explored. It may be that most of the deposits of the precious metal are hidden in the ocean. Our descendants will have to find out.