OPERATION FOCUS stacker reclaimer dumping boom. After unloading, the belt runs back onto the stockyard conveyor idlers through deflecting drums. The CCT Ruda KC-3500 stacker has a capacity of 3,500 t / h. From this stockpile, railcars are directly loaded with ore using an EKG-10 shovel.
As stated following its initial use, the mine realised the HAC had further potential and so made adjustments to allow it to also handle waste as well as ore. The HAC was also significantly lengthened from 933 m to 2.2 m and finally to its present length of over 3,000 m.
BELAZ has 60 large mining trucks operating in Muruntau and the satellite Mutinbay pit in addition to a fleet of smaller trucks
the steeply inclined conveyor has allowed NMMC to remove 16 mining trucks from use, reduce dust levels, cut diesel costs, and long term will allow the mine to increase the depth of the Muruntau mine up to 1,000 m and beyond if needed. It has also increased the productivity of existing trucks by 30 % due to the decrease of transportation distance by 3.6 km. The original design saw rock lifted 277 m but this has increased to over 400 m. The conveyor moves at 3.15 m / sec.
The HAC works on the sandwich conveyor design. The operating principle of the high angle conveyor is based on formation of a closed trough composed of a pair of conveyor belts, one being the load-carrying belt ST 5400 from Phoenix CBS( transporting the rock above the ground level) and another being the hold-down belt Phoenix ST 3500( forming the top trough portion and holding the material to be transported by means of clamping devices).
The receiving bin hopper with a capacity of 180 m 3 receives the mined rock from the BELAZ dump trucks. The bin features welded metalwork on the internal surfaces which are also equipped with ribs to protect them against wear. This feeds a 7 ° angle feeder, which uses a speciallydesigned wear-resistant rubber belt instead of a steel apron one, which was more cost effective and prevents fines build up.
A screen for separating the fine fractions from the rock mass is located between the belt feeder and crusher. Application of the screen upstream of the crusher enables output to be raised and the active crushing parts wear to be reduced. The sizer can handle rock up to 1,300 mm diameter and 150 MPa and crushes to 300 mm diameter, with a hydraulic mounted rock breaker for oversize.
The drive station of the high angle conveyor load-carrying belt features a double-drum drive installed on the discharge hopper steel structure. Driving and deflecting drums have linings coated with REMA TIP TOP supplied rubber compounds. A drive station of the high angle hold-down belt
( 2 x 630 kW) is made up of a single-drum drive installed on the steel structure which is an anchor section of the conveyor sloping portion.
Overrunning clutches provided on input shafts of the drive station gearboxes are used to prevent the belts from making any backward motion. A repair truck rides on rails mounted on the top chord of the high angle conveyor steel structure. It is used to carry out the conveyor maintenance and repairs and to deliver the required spare parts. The truck is fitted with a pair of 1,000 kg load capacity and 20 m lift height electric hoists. To inspect the conveyor sloping portion and bring operators to their working places, a pendulum aerial tramway was also provided.
The sloping portion of the high angle conveyer features the steel structure supported with the posts from the concrete basement. The posts are installed, in their turn, on the open pit benches. Thanks to articulated joints between steel structure sections, the conveyor equipment can withstand the seismic effect of drilling and blasting operations. The high angle conveyor section lengths range from 17 m to 51 m with the total length of the sloping portion in the initial installation being 450 m. To provide failure-free operation, the conveyor has all the required safety and control facilities, ie conveyor belt runoff, slip or integrity sensors, prestart audible warning, emergency pull rope, and push-button switches.
To hold down the belt with a load upon breakage of the load-carrying belt or during a conveyor shutdown in emergency, a hold-down belt catcher, one-way rotational rollers and overrunning clutches built into the drive gearboxes are installed.
Upon lifting the rock mass above the open pit edge, it may be loaded onto the stockyard conveyor, then transferred to the stacker reclaimer and finally, loaded in any desired vehicle or stacked. The load-carrying belt of the stockyard conveyor lifts the load along a specially adapted sloping ramp to the transfer point for loading onto the conveyor of the
BELAZ in Uzbekistan
BELAZ has been present in the Uzbekistan market since the 1960s. In the region of 1,000 units of different payload classes and various models have been delivered to the country since independence in 1991. Historically the three major customers of BELAZ in Uzbekistan have been NMMC; Almalyk MMC( also known as AGMK); and UzbekCoal( also known as UzbekUgol).
Uzbekistan customers were the first BELAZ customers globally to use its AC-AC technologies on 136 t trucks in the 2000s – an important milestone for BELAZ in its development to meet the challenging requirements of the mining industry. BELAZ says it“ always regarded Uzbekistan as an important strategic customer in the Central Asia region over the years and this continues today.”
Since 2009, BELAZ has been represented in the country by dealer Diezel Komplekt. In that time more than 200 units of BELAZ trucks have been supplied to Uzbekistan and about 40 % of this fleet has been electric drive trucks of 130 and 220 t capacity. Among other BELAZ endusers in Uzbekistan in addition to the mines mentioned are the limestone quarries of various cement plants: Qizilqum Sement, AkhangaranCement and KuvasayCement; the phosphate miner and producer of fertilisers Ammofos-MAXAM; gypsum and limestone producer Knauf Gips Bukhara; and the iron ore miner and metallurgical works operator UzbekSteel. Machines were also suppled for the construction of the Tupalang hydropower plant.
Diezel Komplekt is involved in the delivery of equipment and original spare parts and is responsible for guaranteeing service in the country. Post warranty service is done mainly by the end-users themselves who with the help of the dealer by then have gained sufficient experience and built up the necessary support network to do it professionally and up to BELAZ OEM standards.
The dealer told IM:“ Our Uzbekistan customers remain loyal to the BELAZ brand which ensures a highly competitive cost of production, but with technology that is dependable and unsophisticated for
12 International Mining | NOVEMBER 2016