According to preliminary estimates, Sukhoi Log is the largest gold-bearing ore deposit in Russia. However, large reserves are offset by the low average grade of gold in the ore (2.1 - 1.7 g / t), which was the main obstacle to its development. Technological research with the aim of enriching ore has been carried out since the 1960s by various institutes: TsNIGRI, Irgiredmet, VIMS, VNIIKhT, Gintsvetmet, MISiS, KazMehanobr, etc.
The accepted theory is that this original form or deposit of precious metals - gold found in gravel, sand or soil, lying, as it happens almost everywhere in river beds, dead or alive, or under mountain caves - was washed and paved with solid hills by the action of the elements over the years. Washing with water is a versatile way to obtain gold from these deposits. But the scale at which this work is done and the tools of application range from a simple hand-made dish and pick and shovel of an individual and original miner working along the banks of a small stream, to large combination enterprises to alter the entire course of a river, running shafts down hundreds of feet to get into the layers of old streams, and bring water through ditches and flumes and fine pipes for 10 or 20 miles to wash away the golden gravel hill and get to its precious particles.
The history of the discovery and development of the field
The Sukhoi Log gold deposit was discovered in 1961 and intensively explored in the 1970s.
Since June 1986, a complex of preparatory work has been carried out:
- Power transmission line 220 kV Taksimo - connected with the central Siberian power system,
- construction of the Telmamskaya HPP with a capacity of 450 MW has begun.,
- construction of a year-round road Taksimo-Bodaibo-Sukhoi Log,
- reconstruction of the airport runway in, - zero-cycle works for a gold recovery plant were started directly at the deposit.
In 2007-2008, the TsNIGRI Institute, with the involvement of contractors, carried out a reassessment of the deposit's reserves. As a result, a new ore processing scheme was proposed: the use of photometric separation at the head of the process and the subsequent gravity-flotation scheme.
Plain individual pucks are generally "pushed" for the richer sands of Idaho and Montana; that of this kind of gold prospecting in California remains in the hands of the patient and the cunning "John Chinaman", who is working on the forgotten sands of his predecessors and content to reap a dollar a day's harvest.
Other funds are used on a larger or smaller scale, in combination and capital. In fact, all forms of gold washing are intermingled; and companies of two or three people, sometimes from the Chinese, with capitals of hundreds of dollars, buy a gateway or grab a desert bed, and with a shovel and brush and a small stream of water, sands run through the gateway and at the end of the day, week or month collect deposits of gold at the bottoms or ends of their sluices. From this point onwards, operations rise to hundreds of thousands and are used by hundreds of men as partners or day laborers for managers.
Geographical position
The Sukhoi Log deposit is located in the central part of the Lensky gold ore region, 850 km from, 137 km from Bodaibo and 357 km from the nearest railway. Taksimo station ().
The deposit is located on the territory of the Lensky gold-bearing region. In addition to this giant, 5 more medium-sized deposits of a similar vein-disseminated gold-quartz-sulfide type with relatively low (by world standards) contents of 2.5-3.5 g / t were discovered there - Vysochaishye, Zapadnoye, Verninskoye, Chertovo Koryto, Nevskoye. The first three are already being developed, and for two, work is underway to master them.
Erecting gold sands and gravels from deeply covered layers of old streams running down mines and from tunnels into and through such layers, and then washing them, is called "Deep Digging" or "Fang Catwalk", and in their pursuit the days of ancient rivers will be pass through the country mile after mile and several feet below the present surface of the earth. Harder deposits of gold particles are themselves. Usually, in large operations of this kind, the main stream of water is divided into the outlet hose into two or more streams, which pour out towards the hill, as if from several fire engines, only with tremendous force.
Geological characteristic
The deposit is located within the Marakano-Tunguska syncline in the central part of the Bodaibo synclinorium. Gold mineralization is represented by sheared carbonaceous meta-silty schists with thin layers of siltstones and phyllites containing scattered inclusions, veinlets, nests, lenses, lenticular and veinlet inclusions of carbonates and sulfides, with which gold is associated. 3]
In one of the streams, there would instantly be a person or an animal that had to pass before it, and often because of this, fatal or semi-phase accidents occur. Neighborhood citizens are confident that this will be a rich payoff for the investment, however, and say the main reason it is not going into effect is the lack of specific laws governing mining claims, as well as conflicts and doubts generated by government neglect. will establish the terms of ownership of mining land.
As it is now, squatter sovereignty is an essential law of mountain properties; prospectors and miners have installed several general rules to determine the rights of such another; and they can borrow and use properties that they discover or acquire to a certain extent. No person is allowed to occupy more than a certain step in feet or more than acres.
At the field, according to the conditions of occurrence, size, position in space and the degree of exploration of reserves, four areas have been identified: Sukholozhsky (88.6% of reserves), Central (0.9% of reserves), North-West (10.5%) and Zapadny (under development currently).
According to the geological and genetic type, this deposit belongs to the gold-sulfide disseminated-veinlet in black shale complexes.
Returns obtained in some cases of extensive deep excavation with hydraulic extraction are very high. However, these are extreme cases of luck; other businesses operate with a loss or with variable results; but flushing like common things pay good wages and a fair return on investment.
Of course, all of these operations create widespread waste wherever it occurs and that continues. A tornado, flood, earthquake and volcano together are unlikely to cause more devastation, spreading more ruin and ruin than can be seen everywhere along the path of large gold-washing operations. None of the inland streams of California, although naturally clear as crystal, avoid the change in thick yellow mud for this reason, early in their development or in the hills. Sacramento is worse than Missouri.
Orebody morphology
The ore body is represented by a bed-like deposit, the thickness of which varies from 15 m on the flanks of the deposit to 140 m in its central part and averages about 70 m. the ore body has no day surface and natural boundaries. Inside the ore body, there are areas of low-gold-bearing rocks with an average gold grade of less than 1 g / t, the selective mining of which is not possible. The host rocks are composed of thin-bedded black shales and siltstones.
Many streams end up from source channels, either directly for mining purposes, or as a result of the large masses of soil and gravel that descend from the gold leavings above. Thousands of acres of shallow land along their shores are forever destroyed by this character's sediments. There are no rights to be respected in California. This is one of the highest interest. A farmer can turn his entire farm into barren waste with a stream of sand and gravel from some hydraulic mine; more if beautiful garden or the garden stands in the way of the work of the rich hive or the shore, the garden and the garden must go away.
Technological type of deposit
The ores of the deposit are of the gold-sulfide-quartz technological type. Previous studies have shown that most of the gold is associated with sulfide minerals, mainly pyrite.
The gold content in the ore varies in the range from 0.5 to 10 g / t and averages 2.7 g / t. Against the background of uniform sulfide mineralization (0.4-1.0%), enriched areas are observed, where the sulfide content rises to 1.5-2.0% and more. The thickness of veinlets and other pyrite formations ranges from fractions of a millimeter to several centimeters. The gold content in pyrite ranges from the first grams per ton to several hundred. Chemical composition ores differ little from the composition of the host rocks.
Then torn apart, dug up, washed to pieces, and then washed over the side hills that were or are in the process of being mined by hydrometeorology, is indeed the chaos of the devil. The country is full of them along mountainous areas the Sierra Nevada mountains and they are truly stunning spots on the face of nature.
Gold-quartz mines are mainly found in the same areas with current or past gold leaching, in the hills and above rich streams and gravel banks. Nevada in the north and Mariposa in the south were the best known counties for this interest. The most successful and noteworthy operations to date are in and around the Grasse Valley town in Nevada County, which has always been a lucrative mining area. It appeared to be almost the only significant mining town in California that we visited that had no free shops or homes and showed signs of decay.
Characteristic of gold
In 2006-2007, large-scale laboratory studies were carried out using photometric separation in order to reassess the reserves of the field.
As a result of the work, a preliminary enrichment technology based on photometric separation was proposed, which made it possible to remove up to 50% of dump coarse tailings with a gold content of less than 0.5 g / t. At the same time, the quality of the product entering deep enrichment is significantly increased.
Among the successful miners and capitalists here, Mr. She has brought an exciting life here, and the city is full of scandals regarding her. The intelligent gentlemen who met her confessed to her intelligence and impressive conversation, and to her captivating mannerisms. The Grass Valley also boasts an old horse that walks alone with the milk carriage, stopping in front of its customers' doors and nowhere else, and provides its daily allowances every day with unwavering fidelity.
But the really great thing about this story is that the Grasse Valley must have a population you can trust to help themselves milk and not accept any of them more than their allocated share. Hero-mines are now receiving increased attention, and extensive new investments are being made in Grands Valley and the neighboring city of Nevada.
Notes (edit)
- Sukhoi Log gold deposit. General information // Goldminer Herald: Prime Gold: site.
- Sukhoi Log is being pushed for trading // Kommersant Siberia. Irkutsk: newspaper.
- Wood B.L., Popov N.P. Sukhoi Log, a giant gold deposit (Siberia). Geology and Geophysics - 2006 - Volume 47 - No. 3, p. 315-341
- Buryak V.A., Khmelevskaya N.M. Sukhoi Log is one of the largest gold deposits in the world (genesis, patterns of mineralization, forecasting criteria). - Vladivostok: Dalnauka, 1997.156 s
- Karpenko I.A., Cheremisin A.A., Kulikov D.A. Morphology, conditions of occurrence and internal structure ore bodies at the Sukhoi Log deposit // Ores and metals - 2008 - № 2 - С.11-26
- Buryak V.A., Khmelevskaya N.M. Sukhoi Log is one of the largest gold deposits in the world (genesis, patterns of mineralization, forecasting criteria). - Vladivostok: Dalnauka, 1997 .-- 156 p.
The auction for the development of the Irkutsk gold and silver deposit, Sukhoi Log, held at the end of January 2017, without embellishment, can be called one of the most significant events in the mining industry, since we are talking about the start of work on a gold-bearing area, which is probably not only the largest in Russia but also possibly the largest in the world.
But here in Mariposa County the interest is different and things are desperate. There are all ten quartz mills, all or nearly all, on the Fremont estate, but now only two or three, and they have moderate results. Villages are decreasing in population; the best people leave; viciousness of all kinds seems to be on the rise, and the looting of motor vehicles is almost nocturnal. His most worthy overseer and manager, Mr. Sheriff, has conceived a six-mouth estate, and his local creditors operate one or two of their mills and mines on a close and economical scale - using the tips of accumulated materials, but not supplying new supplies - to obtain their claims.
History of the study and assessment of reserves of the field
According to official data released by the Russian government, the Sukhoi Log gold and silver deposit located in the Bodaibo region has an area of 7.94 square kilometers. As of January 2016, mineral balances were approved, according to which the gold reserves in the block were estimated at 183,929 tons in category B, 1,188,972 tons in category C1, 277,782 tons in category C2 and 236.608 tons of off-balance resources, subject to open-cast mining. method. In addition, for underground mining, the resource is determined within 285.908 tons of gold.
It's all creep, immense destruction - a gorgeous gentleman holding his head high but wearing his last year's clothes and dining with his friends - a kind of grand earth and my Micawber. value, perhaps great wealth, is still in it, but not of the type or degree that was created for it. But the end to him as a grand duchy, as an endless fountain for political and financial work, will surely come. Indeed, his most striking ability has always been enormous, magnificent debt.
As for silver reserves, for open pit mining they are estimated at 1313.8 tons, for underground - 219.5 tons in the C2 category. Sukhoi Log is the largest field in Russia. This block accounts for 28% of Russian gold reserves, however, until now, the small content of precious metal in the original ore has served as an obstacle to the development of the site.
A few people from her are rich here and in the East; but their wealth has more to do with the sale of stocks and bonds in New York than the profits from his mines in Mariposa. An illustration of all is the best, perhaps in sincere praise, attributed to her most gallant, but not frugal original owner. Why, said the general. There are no reliable statistics on the extent of California quartz mining interest or comparative results on the gold side. The estimate of the outstanding authoritative place in front of me is the number of quartz mills in the state is 600, their cost is twelve million dollars, and their average product is ten dollars per ton of ore at eighteen million dollars per year, But these figures are clearly different from the facts; there can hardly be more than 100 quartz mills, a so-called property, in the whole of California; and they do not share the product of the state with the gold washers equally.
The gold grade is estimated at an average level of 2.7 grams per tonne and ranges from 0.5 grams to 10 grams per tonne at different sites. In parallel with the discovery of Sukhoi Log, five more gold deposits were discovered nearby, the reserves of which are estimated as medium - Nevskoye, Chertovo Koryto, Verninskoye, Zapadnoye and Vysochaishye. The last three are already being mastered, the first two are going through the stage of preparatory work.
It also has rich quartz veins and has eight mills with 84 brands. South Boise is less rich in placer excavations, but has an even greater development of quartz interest. The ore here is the same as in Nevada, it contains more silver than gold. Now there are six mills in the area, one of which is 30 brands. The veins in the Boise and Smith Boise Basins are small, like those of the Reese in Nevada, sometimes going down four inches, but usually increasing four or five feet. The mammoth vein is three to twelve feet wide.
The ore is generally loose and simple and is crushed without roasting. It is incredible that the true value of the ore would be obtained with a real tool of work and the tailings saved. The country is very barren, with the same General characteristics as Eastern Oregon and Nevada. There are some good valleys and there is enough timber for the present, except for the Ovihe area. The population is made up of the majority of the floating, mining elements of California, Oregon and Nevada; people who are always moving towards the newest mines; prosperous today, poor tomorrow.
The block was discovered in 1961, its research was especially intensive in the seventies. Since 1986, preparatory work began in the region with the aim of organizing the start of production. In particular, a 220 kV power transmission line was laid, thanks to which the site was connected to the Siberian energy system, the construction of the Telmamskaya hydroelectric power station with a capacity of 450 MW began, and the road along the Taksimo-Bodaibo-Sukhoi Log route. In addition, in the eighties, work began within the zero cycle, aimed at preparing for the construction of a gold recovery plant. The study of the deposit did not stop.
Four areas have been identified at the deposit according to different criteria, including the conditions of ore occurrence. In particular, 88.6% of reserves are in the Sukholozhsky area, 10.5% - in the North-West, the rest is distributed between the Western and Central areas. Most of the fossil gold is associated with sulfide minerals, mainly pyrite.
As a result of research on Sukhoi Log reserves, which were carried out until the mid-nineties, it was concluded that the development of the site, although it will be associated with large investments, will in any case ensure good profitability of production processes, will make it possible to employ several thousand people and guarantee large tax payments to the budget. The license for the development of the block was originally issued to the Australian company Star Technology Systems, but in 1997, for a number of reasons, the permission was canceled.
By 2003, it became necessary to revalue the reserves of the site due to the increase in the value of gold. This work was entrusted to the Central Research Geological Prospecting Institute of Non-Ferrous and Precious Metals (TsNIGRI). The study was conducted from 2005 to 2008 based on geological and economic data. It was then, according to the results of processing the initial information, that the deposit can be considered the largest gold ore area not only in Russia, but throughout the world.
Experts from the Irkutsk region administration have calculated that mining makes sense in any case, even if the matter concerns the low content of precious metal in the ore. It is emphasized that in the reserves taken on the balance sheet, this figure reaches 3.6 grams per ton, in off-balance sheet - 2 grams per ton. In the world, gold is also mined in areas where the gold content is below a gram per ton.
Fight for Sukhoi Log
In accordance with the decision of the authorities, the auction at which the license for the development of the field was put up was held on January 26, 2017. The start-up payment, according to government decree No. 2550-r of November 30, 2016, was set at 8.551 billion rubles ($ 147 million). It was also indicated that the step in raising rates should leave 855 million rubles. The Union of Gold Producers of Russia commented on the established cost, noting that in terms of the amount of the site's reserves, one ounce was estimated at $ 3, which is ten times less than the usual cost for such tenders. Even before the financial crisis of 2008, experts estimated the license for the field at $ 1 billion.
The competition was attended by two applicants - "SL Gold" and "Gold Bodaibo". The first company is a joint structure of the corporations Polyus and RT-Business Development (a Rostec enterprise), the shares of which are distributed at the level of 51% and 49%, respectively. SL Gold was specially established to participate in the competition. In this enterprise, Polyus received the right to appoint general director and two of the three board members.
In turn, Zoloto Bodaibo is the enterprise of Ibragim Palankoyev, who is associated with the parent structure of Polyus - Polyus Gold International, and VTB. Although the rivals at the auction were not formally connected, analysts are inclined to believe that the second company applied to hedge the first, since in the case of only one bidder, the tender would have been canceled. The possibility of participation in the auction and other structures - "Polymetal", Kinross Gold, Nordgold, was not excluded, but they did not take such a step.
Joint ventures were required for the bidders to meet the criteria set by the government. In particular, the terms of the auction provided that only those companies in which the state's share is at least 25%, both directly and through unitary enterprises or state corporations, could act as bidders. Thus, both applicants achieved compliance with this norm by attracting the state structure Rostec and VTB to the shareholders of the joint venture. According to the agency Prosperity Capital Management, the auction itself was largely due to the position of Rostec, whose management was able to convince the authorities that its alliance with Polyus would act as a structurally optimal shareholder and a reliable block operator.
So, on January 26 of this year, the deposit was played out in a closed tender after the site could not be sold for two decades. The auction lasted only 12 minutes. SL Gold took only one step, increasing the rate to 9.406 billion rubles and won the tender. As a reminder, the Minister announced this immediately after the competition. natural resources countries Sergey Donskoy. Polyus has already transferred a deposit of 8.5 billion rubles to the budget, it follows from the company's report. The results of the competition were confirmed by government decree No. 269-r dated February 15, 2017. The document states that the winner of the auction gets the right to explore and mine gold and silver at the said deposit.
In turn, representatives of "Zoloto Bodaibo" did not bargain and ceded leadership to a competitor. According to the data received from the company, it was counting on a certain price, and therefore did not raise rates. After the end of the competition, the possibility of participating in the Sukhoi Log development project at Bodaibo Gold is no longer considered. However, the results of the auction were quite predictable for analysts. In particular, Société Générale and BCS Global Markets prior to the auction noted that SL Gold has clear advantages over Bodaibo Gold.
For comparison, one of the largest gold deposits in Russia, which was put up for the competition, was Natalkinskoe (Magadan region). In the middle of the 2000s, it was sold in a tender in which four companies participated, and the starting price during the auction increased 13 times. The National Resource Governance Institute commented on the situation with Sukhoi Log, stressing that before such auctions, the state should conduct an active marketing plan campaign among potential applicants for the field, and only in this case the fruits of competition will be attractive.
Winner's plans and expert predictions
Long before the auction, Polymetal, which had shown interest in buying out this block, said that the deposit's peculiarity lies not only in its rich reserves, but also in the fact that this block has a strategic status. The corporation noted that the operator that will receive such a field will in fact become a mining monopoly in the region. American Appraisal Russia noted that the purchase of the field was carried out at a good time, since the period low prices it goes to gold and they will have time to recover by the start of mining. The block was not ready for development in the nineties and two thousand years, now its turn has come, the agency emphasized.
Gold mining at the deposit will begin this year, said Irkutsk Governor Sergei Levchenko after the auction. It is assumed that the additional exploration of the site, as well as the preparation of the corresponding feasibility study, will take about three years. In Rosnedra, they stressed that the launch of production will take place in eight years.
The available reserves will be enough for the extraction of precious metals for half a century. According to the Ministry of Natural Resources, in the first 33 years the block will be developed by the open-cut method, the rest of the time - underground. As a result, approximately two thousand tons of gold and half a thousand tons of silver will be mined. The Central Research Geological Prospecting Institute of Non-Ferrous and Precious Metals calculated that the total development period of the site will be within forty years, ten of which will be spent on additional study of geology, as well as on the construction of the GOK.
Polyus reported that after the preparation of the feasibility study, various options for the infrastructure arrangement will be proposed. It is quite possible that, due to the similarity of the chemical and mineral composition of the Sukhoi Log ores, the methods already used in the development of the Verninskoye deposit, located only twenty kilometers away, will be used. According to the results of the studies carried out by TsNIGRI, it was proposed to apply the technology of preliminary enrichment based on photometric separation. This method removes up to half of the large tailings that contain less than half a gram of gold per tonne.
The company believes that the new asset provides enhanced synergy opportunities with existing blocks. The corporation sees the Irkutsk region as one of the key and stable ones in the field of gold mining. Polyus directly through SL Zoloto will be responsible for the overall project implementation and will act as the site operator. In the future, Polyus will increase its stake in SL Gold to 74.9%, or 23.9 percentage points. The purchase of additional assets will cost the company $ 141 million. After the deal is closed, Rostec will hold the remaining 25.1% of the joint venture. Funds will be paid out in installments over a five-year period with early remittance options.
Already now, Polyus is studying the option of a secondary placement of securities and the sale of a quarter of its shares. Obtaining a license for the development of Sukhoi Log will give the company additional advantages in negotiations with potential investors, since such an asset is a serious argument for the next ten years. Nevertheless, the new license is unlikely to have a positive effect on the value of shares during the public offering, since external factors play against Polyus - the trend towards cheaper metal and an increase in the ruble exchange rate.
Estimates of project implementation costs
According to the Union of Gold Producers of Russia, the costs associated with the development of the deposit are estimated at $ 4-5 billion. In turn, the Ministry of Natural Resources believes that the costs will be much more modest - up to $ 1.7 billion. that it should be remembered about the costs of creating the necessary infrastructure. The construction of the plant, designed to process 17 million tons of ore per year, will require $ 750 million.
According to TsNIGRI calculations, the expected volume of investments will be at the level of 49 billion rubles in 2008 prices ($ 1.8 billion at the exchange rate of that time), including 38.5 billion rubles to be invested in the construction of industrial facilities, and 4.7 billion rubles for the related infrastructure. rubles. In addition, expenses for one ton of ore will reach 4,226 thousand rubles. The payback period is expected within 12 years, and the development profitability - at around 30%.
According to the American Appraisal Russia consulting agency, at the first stage of work, the operator will have enough up to $ 2 billion. The Polymetal company said even before the tender that Sukhoi Log, taking into account the need to build infrastructure, as well as its complexity in terms of economic and technical questions can require a huge waste of money. Back in 2006, the company calculated that the development of the block would have to be financed in the amount of about $ 1.5 billion, with a payback period of at least a decade.
Industry analysts are of the opinion that the deposit is clearly interesting to investors, despite the fact that investments in the project are significant. First of all, it is noted that the costs will be offset due to the high cost of gold around the world. In addition, the clearly underestimated cost of the license is an important saving factor.
The company itself, as well as Rostec, refrained from making financial assessments. In any case, the expected costs of the project are colossal, however, according to experts, Polyus will cope with such a volume of costs. And if it is quite possible to make a mistake in calculating financial costs, then the global significance of the implementation of such a project as a whole is difficult to overestimate. Getting started on largest deposit, which has been idle for 56 years since its opening, can be safely regarded as a qualitative breakthrough in the development of modern Russian gold mining.
