Serbia: Kolubara mining basin, Coal production in the Field “D”, Mining
The July production was planned only when the dramatic consequences of the floods were perceived and when it became clear that the Field “D” would have to carry a great deal of burden of the difficult situation which affected Mining Basin “Kolubara” company. MB Kolubara produces more than 50% of Serbian coal which is delivered to Serbian power plants TENT producing more than 50% of Serbian electricity.
Open pit mine Field “D” in June and July was the backbone of the production Mining Basin “Kolubara”. According to Ranko Ristić, co-ordinator of the coal production and quality in the Field “D” more than 1,100,00 million tons of lignite was produced in July. In that way, the ambitious plan of 740,000 tons was significantly exceeded, which was made when they perceived the dramatic consequences of the floods and when it became clear that the Field “D” would have to bear a big part of the difficult situation burden which affected MB “Kolubara” . The production was kept at the optimal level despite the malfunction on the excavator, “Glodar 7”, due to which the excavator was out of service for five days in July.
Production level in June was also a big accomplishment of the employees of the Field “D”. The plan was exceeded by four and a half time, with the production of 998,500 tons of lignite compared to 220,000 tones which were planned. After the May floods and blockade of Tamnava OPMs, all eyes were set on Field “D”, as the only OPM which could achieve the optimal level of production fast. Due to this fact, the employees were fully aware of the importance of their role, not only for “Kolubara”, but for the entire Serbia. They managed to exceed the production plan in June and July by enormous efforts and not only they justified the trust, but they also overcame the most optimistic expectations.
As a reminder, in a huge flood wave, in the Field “D” the pumps, that were not able to extract huge amounts of water from the mine, were submerged. Thanks to the fast action of employees, excavators were drawn out to a safe place and four pumps were saved. Along the ESL and ESSc line the middle part of the belt was flooded in the length of 400meters. All the equipment was saved by around the clock operation. The only material damage was caused by the delays in the lignite production, which lasted 11 days.
– Although, excavators were not flooded during the May floods, submerged conveyor belts were a big problem, due to which it wasn’t possible to transport the coal to the thermal power plant “Nikola Tesla”. Water was quickly pumped out by utilizing a larger number of pumps, which were borrowed from Field” B “and OPM” Drmno “and mounting of pipelines. On 26th May, the bench conveyor belt for the ESSc system was put in operation and the production and coal transport from the mine started. A decision to bridge the second submerged bench belt on the ESL line was adopted, because , according to the calculation, the assembly of a new bench conveyor belt would take less time than recovery. The assembly lasted for 10 days and the ESL line was put in operation on 5th June. During the first days after starting the system, the production was lower due to a problem with the transport, because the floods had damaged the railway towards Obrenovac. When the coal transport from Vreoci to Obrenovac was regulated, the production increased – explained Mr. Ristić.
Mr. Ristić emphasises that for the achieved success they owe the gratitude to the management of “Kolubara”, and the management of the open pit mines, who put at their disposal the necessary equipment, as well as to the colleagues from Tamnava mines. Without their support and good coordination of all departments, this success would not be possible.
Overhauls before the floods
Overhauls in the Field “ D” were done before the floods. An investment overhaul of the “Glodar 8” started in April and finished on 10th May. The investment overhaul of the “Glodar 7” was planned for June, so that the stand- still of the system was used for the necessary overhauls.