PJSC Severalmaz is a subsidiary of ALROSA – the world leading producer of rough-diamonds. Severalmaz main activity is mining the largest in Europe primary diamond deposit named after M.V. Lomonosov. All operations are carried out under the project “The mining and processing plant of Lomonosov diamond field with annual capacity of 4 million tons of ore” drafted by the Project Institute “Yakutniproalmaz” in 2013.
Lomonosov diamond deposit is unique with no analogues in the world due to combination of geological and mining characteristics. It consists of 6 kimberlite pipes: Arkhangelskaya, Karpinsky-1, Karpinsky-2, Pionerskaya, Pomorskaya and Lomonosov, forming a chain of 9.5 km in length. Total reserves of the deposit are more than 280 million tons of ore (GKZ classification), total mineral resources are more than 285 million tons of ore (JORC classification).
Nowadays Severalmaz performs all mining operations on two southern kimberlite pipes – Arkhangelskaya and Karpinsky-1. The company uses classical way of excavating – open pit mining without blasting, with the use of hydraulic excavators with bucket capacity 7 and 15 m3. Ore is transported first to ore storages and then to the processing plant, waste rocks are transported to dumps. Annual mining capacity of the plant is 4 million tons of ore and about 13 million m3 of waste rocks. Severalmaz’s car park in 2017 consists of 5 excavators, 39 pit tracks and 8 bulldozers.
A complicated drainage system was constructed for safe mining on the Lomonosov diamond field. It consists of 75 dewatering wells around both pits and 2 in-pit dewatering stations. Total capacity of the drainage system is about 6000 m3 of ground water per hour. The drainage system meets all ecological requirements.
Ore processing plant comprises two technological lines, which were put into operation in 2005 and 2013. The main technology stages are self-crushing of ore in a mill, density separation, X-ray separation, diamond sieving by size classes and chemical cleaning of diamonds. Annual capacity of the processing plant is 4 million tons of ore. The processing technology, created by Russian specialists, is at the world standards level, and in some stages exceeds it.
At the final stage all diamonds are sent to the diamond sorting center, where diamonds are classified, sorted and graded according to all classification features shape, size, color and quality. Specialists also carry out certification of diamonds larger than 10.8 carats. After sorting rough diamonds are sent to the Sales organization – subsidiary of ALROSA.