The Udachnaya Kimberlite Pipe was discovered in 1955 in the Daldyn River basin by a team led by V.N. Shchukin. Preliminary exploration to a depth of 400 meters was completed in 1960. During the second stage of prospecting work (which lasted until 1972), detailed exploration of the field was conducted to a depth of 800 meters. At present, exploration of the western and eastern ore bodies to a depth of 1400 meters is finished, and extraction is being conducted at a depth of more than 500 meters.

The project of the industrial development of the Udachnaya Pipe specifies developing the field using the open-cut method to the minus-290-meter mark. Underground mining is subsequently planned. Preparations for building the Udachnaya underground mine, which will allow prolonging the term of development of this unique field for no less than for 50 years, started on November 7, 2001 when the Udachninsky prospecting party of the Amakinsky expedition started drilling test wellbores on the site of the future mine, 600 meters from the edge of the Udachnaya opencast mine. Research of the extracted samples has provided information on the properties of the massif with regard to stability of massive material, water inflow, use of possible types of fastening for mining equipment, etc.

In 2002, the management of the underground mine under construction was assembled at the Udachninsky mining and processing combine. Project institutes developed a feasibility report on investments in construction, and management prepared approval documentation on tunneling a trial underground site of the mine at the minus-170-meter horizon of the Udachny opencast mine and vertical shafts of the mine site located at the edge of the opencast mine.

The portals for the pilot production site were built by early 2004. Alrosa’s Yakutniproamlaz Institute developed the design documentation for tunneling at the pilot production site, the accelerated opening of a working horizon at minus 380 meters, advancing of a spiral ramp between horizons at 305 and 380 meters, advancing crossdrifts to an auxiliary ventilating shaft of mine. Filling operations and equipping are in progress for Alrosa’s largest mine site, the Udachnaya underground mine, the design capacity of which is four million tonnes of ore per year.

At present, tunneling of the auxiliary ventilating shaft is finished, the bolted area is tamped, and reinforcement of the shaft is in progress and is planned to be completed this year. The Alliance of Mining Companies has tunneled approximately 140 running meters of a vertical skip shaft, and work has been performed on a two-way intersection and a skip loading system at the 835-meter mark. Final tunneling of the skip shaft is planned to be completed in December 2009. More than 800 running meters of access ramp were tunneled in 2008.

For the last 25 years, the Udachninsky mining and processing combine has been leading company in Russia’s diamond-mining sector and the largest operating opencast mine in the world, with the company’s largest volume of diamond extraction.
       
The Udachnaya field is located in the northwest of Yakutia, 12 kilometers from the Arctic Circle in the permafrost zone. The climate in this region is severe and extremely continental. Winter lasts eight months and the temperature can fall down to -65°C. Summer is short and hot, with temperatures of up to +35°C. The average yearly temperature is -14°C.

The first development project of the primary deposit using the open-cut method was completed to a depth of 400 meters by VNIIPROzoloto and Yakutniproamlaz institutes in 1970. Mining work on the field started in 1971, and in May 1974, a plan for supplying ore from the opencast mine Udachnaya to Mill No.11 by motor transport was implemented. Development of the steep-grade ore body was carried out with the application of ring system of development, with development of mining works from the center to the periphery. In the working zone, horizons were opened with temporary crossovers.

In 1987, with a view of involving deep horizons in the diamond field in operations and maintaining the Udachninsky mining and processing combine’s production capacities, the Yakutniproamlaz institute developed a project to renovate the Udachny opencast mine. The gradients of slope of the benches were changed from 60 to 75 degrees depending on depth of their location. The height of working benches is 15 meters.

The design depth of the opencast mine is 600 meters. The project specifies the creation of three intermediate envelopes (at depths of 300, 400 and 500meters) with interconnected ramps in the open pit envelopes of the Udachny opencast mine at a depth of 600 meters.

A project for deepening of Udachny opencast mine by 30 meters – to the minus-320-meter mark – is currently being prepared. The Uralgiproruda Institute is leading the project. This will be the final stage in the opencast mine’s operations. Ore extraction using the open-cut method will be conducted until the first half of the 2011, and then there will be a systematic transition to underground development.

The combine is currently extracting ore at the Zarnitsa pipe, the first primary deposit of diamonds discovered in the Soviet Union, located 23 kilometers away from Udachny.

On August 22, 1967, Beneficiation Mill No. 11 was commissioned at the Udachnaya pipe’s field. In 1976, the first stage was commissioned, and in 1978, the second stage of Russia’s largest diamond-industry beneficiation mill started operations.

The design ore processing volume of Mill No. 12 is 11 million tonnes per year, making it Alrosa’s most productive mill. The mill is currently equipped with seven nine-meter autogenous grinders, five of which have been made in Japan and two by the Russian Syzran plant.

Owing to its geographical remoteness from industrial regions, the Udachninsky mining and processing combine is a compact company, the structure of which includes divisions providing for basic production – the Udachny opencast mine, beneficiation mill, tailing facility unit, utility vehicles motor pool and municipal and local utilities unit.

Specialized organizations perform the necessary repair and construction work. The industrial area’s power supply is provided by a double-chain LEP-110 kWt power line from the Viliuisky Hydroelectric Power Station, located 430 kilometers away from the settlement of Udachny.

Alrosa pays special attention to issues of neutralizing the impact of mining production on the environment of northern Yakutia. The Udachny open-cast mine’s highly mineralized waters pose a serious threat to flora and fauna of adjacent areas; therefore, dumping these brines in the river or on the topsoil is out of the question. Udachninsky mining and processing combine has successfully implemented a system of underground warehousing of brines in the fault lines of perpetually frozen rock refuse.