Hundreds of years, humanity is covered by the Golden Fever. The precious metal of the Sun colors from ancient times is a symbol of wealth, power and power. In the modern world, a large gold reserve of the country guarantees and ensures the economic security, stability and independence of the state. In nature, gold reserves are not limitless, but in our days, large deposits of precious metal are opened and developed.
What kind of rocks contains?
The main gold supply of our planet is kept in the depths of the Earth. As a result of volcanic processes, gold with magma fell on the surface and froze in alloy with other substances in rocks. Processes occurred unevenly, therefore the precious metal is not everywhere. A large number of quartz, granite and sulfide ores - pyrite, marcatite, pyrrhotite, ammonite and others are indicated on the close location of gold.
Gold deposits are two species.
- Primary or Native If gold is in rocks. Most often, the precious metal in small enclosures is included in the ore from which it must be removed. If 5-7 grams of gold were obtained from a ton of stones in an industrial way, then this ore is considered gold, and if more, the deposit is called the Golden Residential.
- Rosser or secondary When, under the influence of natural phenomena, the stones are broken, grind, and the golden grains included in them are settled at the bottom of the mountain rivers and lakes.
What does it look like?
In nature, gold does not look familiar to us and happen different shades: from gray-green to red. Many rocks in placers are very similar to the precious metal. Especially often it is confused with a sulfur creek - pyrite. For this, pyrite nicknamed "dog gold." Identify precious metal is quite simple - It is necessary to spend a thin needle on the stone. If it is a pyrite or other mineral, it will turn around, and if real gold is not.
But not all stones like gold-containing, you can Check mechanical effect. In such cases, resort to Chemical verification method. For this, the studied stone is immersed in sulfuric acid: during the reaction, the sulphides will darken, and with gold will not happen. There is also such a miracle of nature as gold in pure form - nugget . They are obtained in the course of active leaching of gold-containing sulphides, while minerals dissolve, and the precious metal remains.
The largest Russian nugget weighing more than 36 kg was found in the South Urals in 1842.
How to get?
Many centuries Humanity worked on the problem of gold mining . In the Middle Ages, Alchemists tried to get a "philosopher's stone", allowing to turn the ore into a noble metal. But their experiments were not crowned with success. Nowadays, modern technologies allow you to extract the maximum amount of precious metal from the gold ore. At affinent factories, the material is carefully treated, cleaning from impurities, produce flotation with special reagents, pressed and dried in the furnace. In the future, on the hydrometallurgical plant, the resulting concentrate is integrated into gold bars.
Our land keeps a lot of mysteries and secrets. New deposits of precious metals are opened, Developed more advanced methods of affinage . Gold is still ruled by the world, so finding stones with cherished solar lodge or nuggets seeks an increasing number of people.
It is possible to extract gold from stone at home. When choosing a method, the main properties of precious metal are taken into account.
- Inertia does not give to collapse under the influence of most acids and alkalis.
- High density and severity ensure the maximum efficiency of the precious metal separation from others with the most ancient and simple production method - flushing.
- Softness and plasticity allow even with ultra-long thicknesses to maintain their properties.
- Under the influence of high temperatures, the noble metal melts and boils. Liquid gold when melting loses its density and evaporates long before boiling.
Knowledge of basic properties helps to highlight gold particles from stone in the home laboratory and not losing any grains.
There are several basic methods of affinage.
Dry
Gold stones immerse yourself in a special unit, A reminiscent mill, and thoroughly grind in fine powder. The resulting mixture treated with gaseous chlorom . The occurring chemical reaction allows separating the precious metal from minerals, since it converts all non-metallic elements into a gaseous state. The dry method of affinity requires strict adherence to all precautions.
Chemical
This method is often practiced by jewelers and amateur chemists that allocate gold elements not only from stones, but also from radio components, chips, contacts and transistors. You can make chemical affinity with the help of several reagents. The method is based on the peculiarities of metals and minerals in reactions with acids and alkalis.
First stage with Salo or Sulfuric acid All non-metallic elements are removed. At the second stage, a mixture of metals is dissolved in nitric acid at constant heating. The resulting composition is immersed in hydrochloric acid and added periodically dropwise nitrogen. Next, the mixture is evaporated to dry state and is poured with an aqueous solution of iron sulfate. The resulting sediment of brown is boiled in concentrated nitric acid, while the last remains of foreign impurities are removed, and gold remains.
With the help of electrolysis
In a transparent spacious capacity with a solution of hydrochloric acid, gold chloride is immersed and the electric current is connected. During the reaction there is a gradual drop in the current strength. This means that the oxidation process has ended and the precious metal is fully cleaned.
With the help of chlorine tin
In the vessel in equal proportions, water and hydrochloric acid are poured, a tin chloride powder is added. Grinding gold-containing stones are immersed in the resulting solution. After about a day, the precipitate formed is filtered and for complete purification from impurities boiled in hydrochloric acid.
Flushing
From a long time, one of the easiest and safest methods of gold mining is Flushing . In the shallow water of the mountain rivers, sand from the bottom is passed through a sieve, while the particles of the precious metal remain on the grid, and less severe impurities are removed by the flow of water.
In ancient Greece and in the Caucasus for gold mining, she used sheep skins . It was fixed in a special way at the bottom of the river. Under the onslaught of water, small sands easily penetrated through the skin, and the heavy grains of gold remained on wool. Gradually, the white fleece became completely gold. Argonauts from an ancient Greek myth are not in vain so many works put in search of a golden rune.
In those days, the noble metal was not only a symbol of wealth, but also the absolute power of the country.
Table Miller
It is possible to separate the gold from the stones and the sand by flushing at home. For this purpose buy or Make a table Miller - Special box with a width of 25 cm and a length of 50 cm. The hard rug is placed on the bottom. The material under study (sand, fine-finished stones) is loaded into the box and washed under constant flow of water. As a result, the lungs in the weight of the grains and particles of minerals are washed away, and heavier golden grains settled on the rug.
In Russia, prospectors are allowed to produce a precious metal on spent mines and small places. To do this, you must purchase the appropriate license.
Security measures
In working with acids and alkalis, you must follow safety rules. Finding into open areas of the skin, the reagents cause a chemical burn. It is important to remember that in evaporation they allocate poisonous gases dangerous to human health and can damage organs of vision and respiration.
All work should be carried out in a well-ventilated room with an exhaust and use individual means of protection - rubber gloves, mask, overalls.
The following video presents one of the most effective methods of obtaining gold from the breed.