where can i go gold mining

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Currently, gold is mined primarily from ores , not only gold, but also those in which the main mineral resources are other non-ferrous metals such as copper, zinc, silver and lead . In this case, considered as a fellow traveler . In all industrialized countries, for example , is widely practiced gold production from copper and lead – zinc ores . For example, in 1970 in the USA were produced in this way 26% of the total gold production. The same pattern is observed in many countries, where non-ferrous metals are extracted , which fully corresponds to the presently accepted in the world practice direction on the comprehensive utilization of mineral resources . The gold content of nonferrous metal ore is usually much lower than gold ores directly , but production cost of its production can thus be somewhat less. It should be noted that gold mining in this case will depend on the demand for other non-ferrous metals . So , in 80 years in the U.S. tailwind gold mining has decreased markedly due to lower copper prices.

Significant amount of gold mined from the development now silver deposits , as the demand for silver is great and has a tendency to further growth , the source of this precious metal is more reliable . This kind of deposits are often epithermal origin.
When passing gold mining mining essentially remain the same, but the processes of enrichment and metallurgical processing of ores become much more complicated , as you need to get is not one, but several metals.

Placer deposits are also source of gold, but in the last few decades in Western countries, their value has been steadily declining . Just a hundred years ago placer mined almost 90 % of the gold . In the 70s of the last century have they accounted for no more than 3-5 %. In recent years due to rising gold prices and the opening of new fields , primarily in Brazil , the value of placer usually precious metal suppliers western countries has increased to 14-15% . It may well be that in the future to continue the growth of some placer gold , but no doubt that the main thing today – the development of primary deposits .

There is another source of income gold – often known as the secondary metal. Of course, this source in its scale is still small , but with the expansion of the scope of the industrial use of gold will increase its value .

Called secondary gold derived from the processing of failed or end-of- century products , which include those ( in any quantity ) available gold.
Indigenous gold deposits made ​​mostly in quartz veins , thickness (power) which , as well as the angle and length of occurrence can be very different . Also different sizes of gold inclusions and their number. The thickness of the quartz veins may reach several tens of meters , or be less than 10 cm However, in the latter case is not about the core , but the veins. Veins may be single or whole families lie . There are cases where a lot of small veins and veinlets form a whole ore zone .

Most favorable conditions for underground mining occur when many small veins and veinlets form a powerful ore zone , which can develop with the use of the most efficient systems and mobile equipment . However, it is necessary to remove large volumes of waste rock that diluting the ore. In developing such zones the average gold grade is usually low .
Gold deposits are often unprofitable to develop open way. Thin ore veins usually go deep into the cool , which makes access to fossil fuel, with an open design, as with depth for each ton of ore falls more and more barren rocks . A number indicating how many times the overburden is removed than ore miners called stripping ratio .
Quarry mining is considered the most progressive , and its share has been steadily increasing in all countries , but in practice, gold mining is widely used underground work, as the stripping ratio during open- finely stranded deposits would be too great. Therefore, open pit mines in the gold mining industry is not so much – ” Cortez ” and ” Carlin ” in the U.S. , ” Grenayzl ” in Canada and others. One of the largest quarry ( open pit mines ) is located in the Dominican Republic . Its annual production – nearly 10 tons of gold .

The difficulty of developing gold deposits also connected with the great fortress of rocks , primarily quartz, from which often consist of the core. In some cases, the upper , the so-called ” oxidized ” deposits of quartz areas is severely damaged due to weathering , but with increasing depth development of its strength increases. Difficult to develop and variability of the angle of incidence of the ore veins , which requires additional exploration expenditures and often causes already in operation to revise many of the technological solutions .

Performance gold mines significantly inferior not only to iron ore and coal mines , but many mines , develop the field of non-ferrous metals. To produce 1 kg of gold with its contents in a ton of ore 4-5 grams ( such content is typical nowadays for many fields developed in Western countries ) need to repel , to give to the surface and processed 200 – 250 tons of ore to produce 1 ton of gold need to develop 200-250 thousand tons of ore.

Of this vast amount of ore must somehow allocate a small amount of gold contained in the Convention , and to make it so that in the process of selection ( enrichment ) not to lose precious metal.
If we talk about the substance of gold ore enrichment , it is not very different from that which was at the time Agatharchides , Pliny , Biruni and Agricola. Exhaustive characterization of the spirit gave Biruni : ” When gold is connected with the stone , it needs grinding and grind it on millstones , although the pounding it with a rather crowding and better ensure its quality … when gold ore istolchena or milled , it ( gold) separated washing the breed, and then collected by gold mercury , then it is pushed into the piece of skin. The remaining mercury is removed by evaporation . ”

Crushing, grinding , washing, amalgamation – all these operations exist in our time , but they are made with the help of much more advanced technology. In this respect, primitive throng , for example, funny compare with modern crushers and ball or rod mills and autogenous mills . But the essence of the process remains the same .

For crushing and grinding ore modern industry produces powerful and heavy installation occupying a lot of space , requiring bulky foundations which consume large amounts of electricity . Initially, ore crusher falls into which you can load chunks the size of 1.5-2 meters. Passing through a series of successive different device crusher , ore is crushed to 8 – 9 mm. If the inclusion of gold in the ore are small, then it goes further refinement , which resulted in the ore particles reach sizes equal to hundredths of a millimeter. This whole process is called ore preparation , it is very time-consuming and costly , especially for hard ores.

During crushing releases massive amounts of silica dust , very harmful to human health. The reduction or sequestration of this dust is worth a lot of resources . All this makes us actively seek a replacement bulky and heavy crushers . Currently, there are several proposals – fragmentation using ultrasound, discharge electric current , vibration , etc. . But while many gold extracting factory equipped with more mechanical crushers and any medieval miner , he found himself in the modern enterprise , immediately he would have found familiar mechanical preparation methods ore for enrichment.
Preparation processes are virtually identical for all ores , no matter what methods produce further mineral extraction .

In the simplest case, when the native gold in quartz is directly and sizes of gold particles are not too small, the extraction can be done by gravity methods. These methods are in full compliance with its name based on the extensive deposition of heavy gold particles in an aqueous medium in comparison with the much more light particles surrounding rocks. The main gravity method for gold extraction plants in the sediment is specially jigs. In addition, the enrichment process involves concentration on Shaking tables or other types of hubs, sometimes processing in spiral or centrifugal separators, etc. As a result of the enrichment obtained concentrate – material in which the gold content per unit mass is much higher than in the original ore. This concentrate has more than gold and other heavy minerals contained in the ore. The concentrate is processed again, but other methods, most often hydro metallurgical (eg dissolution in cyanide) or amalgamation (treating mercury).

After such processing of hubs get a “rough” gold. It is still largely littered with all sorts of impurities. Further purification process called refining it with all sorts of impurities. Further purification process called refining, he has made at other plants. Thus, the end product of a gold processing plant and a whole gold mine is often “rough” gold.

In some cases, the enrichment of gold ore can be much harder described above. This happens when the gold particles are not in quartz and sulfides (pyrite, chalcopyrite, etc.). The enrichment process greatly complicates arsenic, carbonaceous substances, many metals. Particularly difficult enriched ore with very small inclusions of gold. For release (disclosure, experts say) tiny gold particles requires very fine grinding. If besides gold particles coated with a film of iron oxides “jacket”, then sharply reduced and efficiency hydro metallurgical operations.

The more complex the ore, the process and enrichment. To apply the flotation of sulphide ores, in which the mineral grains useful (in our case – gold) pop up along with air bubbles and foam on the surface of chambers flotation machines, which is separated from the main mass of pulp. To pop the desired mineral, it is necessary to make a non-wetting. To this slurry was added to soda, lime, sulfuric acid and other reagents depending on the ore composition.

Amalgamation process is very simple, but it has a very serious problem – a very poisonous mercury. Poisonous cyanide and, besides cyanidation process is very complex wastewater gold processing plants. So, objectively speaking, the two processes would be desirable to replace the more harmless.

Treatment of industrial effluents gold processing plants today acquired great importance in connection with the protection of nature. The amount of harmful substances, which have to be dealt with on gold extraction plants, especially large, so that worldwide problem of wastewater treatment in the gold mining industry engaged seriously. Recycling of water used, including the lagoon system, where the water returns again to participate in the process, to neutralize harmful impurities using different reagents, etc.

Continuous improvement is the enrichment process in many ways. Many of the new logged in metallurgical processing. Concentrators equipped with special workshops now cyanidation, roasting, began to find wide application sorption technology, etc.

All this is quite a complicated process. However, it should be noted that it is too long the traditional circuit training ore to enriching developed yet our ancestors. And if mining has been some departure from traditional methods (eg, in situ leaching, hydraulic borehole, etc.), in the region of ore dressing until it quietly.
Hopefully, over time, the existing technology of crushing and grinding of ores will be all – still replaced by a more modern processes.

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