On June 25, Russia’s ALROSA celebrated a "both happy and a bit sad" but in any case historic event. Udachny, one of the oldest open-pit mines in Western Yakutia, is ceasing its operation. For the namesake diamond pipe this means transition to underground mining, while the company as a whole is facing the prospect of constructing open-pit mines on other, however more tricky diamond fields, as well as the need to continue exploration.
Soviet geologist Vladimir Shchukin discovered the Udachny diamond pipe when he was 26 years old. Today he is 86, and he had mixed feelings at the ceremony dedicated to the closure of the open-pit mine. Coincidentally, Udachny has completed operations at a level mark of 640 meters – this is exactly the depth to which Vladimir Shchukin explored the reserves of this diamond pipe back in the 1950-60s.
“In 1955, my exploration team had to trot around 1,000 kilometers of routes in search of diamonds,” Vladimir Shchukin said. “However, we discovered the Udachny Diamond Pipe in a matter of one day spending about one and a half hours. This is why we christened it that way, Udachny [Lucky in Russian], because with other diamond pipes everything was much more complicated”.
The team of geologist Shchukin retrieved two diamonds immediately in the first two pits, and one of the diamonds was a perfect octahedron having facets of about 4 mm. For comparison, during the search for the first Soviet diamond pipe, Zarnitsa geologists had to try about 200 pits before the first trove was found. “After the two first findings, we took a small-volume sample - one cubic meter of ground - and recovered another 43 diamonds from it. I knew at once that we had found a large deposit,” Vladimir Shchukin said.
The importance of Vladimir Shchukin’s discovery will become clear to its full extent only later. The Udachny Mine turned to be the largest open pit of ALROSA - both in size and in terms of diamond production. It has become the flagship of ALROSA’s diamond mining operations for many years ahead turning out more than half of diamonds produced in Western Yakutia over its entire mining life from 1967 to 2015. During the 48 years of operation at Udachny, the company took our more than 350 million tons of ore containing diamonds worth about $ 80 billion. At the peak of its career, Udachny yielded about 13 million tonnes of ore per year, annually producing tens of millions of diamond carats.
“Udachny is amazing,” Andrei Zharkov, President of ALROSA said at the ceremony. “This mine is a true example of engineering and mining art. And the diamond field lives up to its name. It is unique on a global scale by the volume of diamonds and ore mined, as well as by the size and structure of the ore body.”
Udachny reached its project depth of 640 meters in 2010, and since then it has not been developed in depth. From 2011 onwards, ALROSA is completing mining operations on the pit-wall ore pillars, which were not taken into account within the initial project and were prospected later. The developing of ore pillars involves operations on the pit walls having high slopes. The company bought articulated dump trucks specially for this project, which are able to work in such conditions, in contrast to the regular ‘heavyweights.’ There is also a possibility to operate remote control equipment in those areas where the pit walls may collapse.
ALROSA performed the final series of drilling and blasting works at Udachny this summer and took out all the ore accumulated on the bottom of the quarry. At the end of the year, as planned, the open pit mine will hear the last explosion, this time not for production purposes. The explosion will partially destroy the spiral road leading to the bottom and form an ore "cushion" reliably separating the pit from the underground mine, which will now take up the production baton.
Despite the end of operations at the open-pit mine, the Udachny Diamond Pipe has reached only the middle of its life cycle. Its reserves have been explored to a depth of about 1,400 meters. There are still 800 meters for underground mining - about 150 million tons of ore, which will last for the next 50 years.
The first phase of the Udachny underground mine was put into operation in June 2014. The mine will pass several development stages to reach its design capacity of 4 million tons of ore in 2019. After that it will be the largest diamond mine of ALROSA bringing the company more than 5 million carats of diamonds annually. In the meantime, the company’s miners are focused on construction and preparatory works planning to produce a total of about 480 thousand tonnes of ore (about 0.78 million carats) in 2015.
This underground mine is not the only production asset, which will remain at Udachny. The long-term program of ALROSA aimed at boosting diamond production to 41 million carats a year assigns an important role for the Udachny Mining Division. Next to the Udachny Diamond Pipe there are other diamond pipes, which will be developed by open-pit mining to provide a work load for the local concentrator and maintain stable production of diamonds in Western Yakutia.
The Zarnitsa Diamond Pipe is the very first primary diamond deposit discovered in the Soviet Union. However, its development has been long delayed, because Udachny was much larger and had a richer diamond grade. Mining operations at Zarnitsa began only in 1998, and until now yielded only small ‘cocurrent’ volumes of diamond ore - about 1 million tons per year. Now it is time for Zarnitsa to step in after the Udachny open-pit mine took its well-deserved rest: starting from the next year, mining operations at Zarnitsa will produce more than 3 million tons of ore. The workforce and equipment of Udachny are being currently transferred to Zarnitsa.
The Zarnitsa open pit is so far very small in comparison with its "big brother," reaching just 80 meters in diameter. In the long term, it can grow up to 800 meters in diameter and at least 200 meters in depth. Zarnitsa has confirmed reserves of more than 120 million tons of ore to the depth of up to 400 meters.
Another 3 million tonnes of ore per year will be added to the Udachny Mining Division production by an entirely new field, which is Verkhne-Munskoye discovered in 2007. ALROSA plans to start developing this diamond field in 2018.
It is worth noting that ALROSA is facing a difficult task. Zarnitsa and Verkhne-Munskoye are much more complicated projects compared with Udachny. These fields have much lower diamond grades than the ‘old’ pipes, from which the Russian diamond mining started. It will be the first time for ALROSA to work on diamond fields having such diamond grades. However, if all the company’s development plans will be implemented, the Udachny Mining Division will once again turn into the largest production unit of ALROSA in 2019.
Alexander Shaburkin, Rough&Polished, Mirny
