News from Tamnava Open pit Mines, “New” system put in operation

26. July 2013. / Mining

The system which began to operate on 10 June is located in the worst part of the coal deposit, where it plays a complex role of operating with both coal and overburden.

In the period of investment repairs at coal systems of Tamnava OPMs, the overburden system of OPM “Veliki Crljeni” was transferred to the mine “Tamnava West Field”to start with operation on 10 June. The 1,540 meters long system consists of a 750 meters long bench belt, two connecting belts of 160 and 430 meters in length and a 1,200 meters long discharge belt.

The Technical Director of the mine “Tamnava West Field”, Miroslav Krnetić, explained why it was important to complete these tasks during the annual overhaul. The overhaul on the second coal line lasted only 15 days. It started on 27 May because of the Excavator 900being taken over from the OPM “Velik iCrljeni”. The excavators were exchanged basically because the Excavator 4 was transferred to the new ECS system of “VelikiCrljeni” to function in combined operation with the Excavator 900 operating on overburden and coal, at which the coal is transferred onto a BC of “Tamnava West Field”. It is located in the western part of “Tamnava”, in the area with the least favorable part of the deposit, with the stripping ratioof60:40 in favor of overburden.The works completed in the past include the power supply and telecommunications. The overhaul in the first week was challenged with some issues hampering the system operation, but those difficulties had been anticipated.

This was one of the moves that, according to Mr. Krnetić, enabled the production of “Tamnava West Field” to achieve a higher level and become more efficient and more reliable.

By setting a new system,transport routes for entering the mine from the direction of the western border were cut off. According to Mr.Krnetić, as soon as the system began to operate, transport routes were displaced to enable smooth operation of all modes of transport in the long run.

– On the other two coal lines, the investment repair covering two bucket wheel excavators 630, a drag line, three mobile transfer conveyors and the “Spreader 3” lasted from 11 May to 4 June.Although the excavators did not undergo capital works, the scope of work was extensive – said Mr. Krnetić. All belt conveyors were displaced to the three coal lines. Additional machinery was borrowed from the other mines to be engaged. Five pipe layers and on average six backhoes were engaged each day.The company “Univerzal” also participated very actively in the repair and did a good job.The company “Univerzal” was increasing the number of engaged workers because it had to make 44 belt joints and to replace about 2.5 kilometers of the belt during the overhaul. On the top of it, nine joints were made at operating overburden systems. To understand the volume of job performed, it will be enough to say that vulcanization of a single joint takes 12 to 16 hours.

Along with the overhaul, numerous jobs were performed aimed at making this mine more efficient, safer and more secure for operation. Also, two dump sites were formed for the interdependence significantly should help in solving the problem of mine dump sites. The inter burden discharge belts were lowered to the projected boundaries, and lowering of the discharge belt O-2 by five meters in relation to the current position is yet to take place, which will help eliminate the problems with landslides at the dump sites of “Tamnava West Field.”

In the same period, investment repairs were performed at the coal system of the mine “Veliki Crljeni” and the Crushing plant. From Milosav Tišma, a mechanical engineer at Crushing plant, we found out that standard works performed this time were of a smaller scale than those performed last year. Out of the important tasks,he mentioned workshop repair of the extractor E-8 gearbox and replacement of the sprocket gear and the stacker transformation rope, coating of the preparation and loading bunkers with rubber and plastic liners. According to Mr. Tišma, the problems also included lack of parts and their receipt during the overhaul, while crusher spins have not arrived at all, so the old ones were put back. The construction company “Građevinar”played a significant role in the bunkers reparation, because without the scaffolding they erected, it would be hard to do this job.

On the BWE 2, Zoran Pavlović, Deputy Mechanical Manager, says that ultrasound control of the excavator critical areas has been conducted. The works performed include replacement of the both bucket wheel gearboxes, bucket wheel regeneration, and replacement of all the damaged lugs on the bucket wheel gear rim. In a workshop of “Metal”, regeneration of all buckets was performed, and the cracks that newly appeared in the area of small tub were repaired. At the belt conveyors of coal system the overhaul is done by the mine mechanical workshop. Seven power units and five pulleys were replaced, in addition to 26 belt joints made by the vulcanization staff.

Quality realized investment repair at both mines will contribute to achieving high operational readiness of equipment in the future.

Source; MBK

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