Overview of recent TAKRAF mining projects

During BAUMA fair 2007 in Munich TAKRAF presented a new mobile stacking and reclaiming system which has been developed for a new leaching project in the Chilean Atacama desert. In the early 90’s TAKRAF was the pioneer of this technology known as “race track leach pad”. Reclaimers, conveyors and spreaders were supplied to El Abra and  Radomiro Tomic and a bucket wheel reclaimer for the PTMS project of Codelco Norte. For the Gaby Project TAKRAF designed and supplied the entire material handling equipment operating on leaching piles and “spent ore” piles, including the mobile stacking and reclaiming bridges (See Fig. 1).

 

 

Fig. 1: Mobile stacking and reclaiming bridges supplied by TAKRAF

 

 

Building on the experiences gained on similar projects, TAKRAF focused in particular on a safe bridge design as well as on achieving the highest possible system availability, i.e. longer bridge segments reduced the number of crawlers and improved controls optimized the movement and alignment of the bridges during operation. The bridges have a total length of approx. 400 m each and can handle
8,300 tph of tertiary crushed oxide copper ore on the incoming (stacking) side, and 9300 tph of “spent ore” on the outgoing (reclaiming) side.

Another copper ore project has recently been completed by TAKRAF in Peru. It included the design and supply of a material handling system which places low grade material into a deep and irregular valley where it will be leached later on. Besides two smaller conveyors the system consists of: one overland conveyor with horizontal curves and a mobile  stacking system. Fig. 2 shows the spreader and the bridge; both are mobile and mounted on crawlers, operating together during the construction of the 12% slope access ramp.

 

 

Fig. 2: Ramp construction by means of mobile bridge and spreader mounted on crawlers

 

 

Once the machines have completed the access ramp,  the mobile bridge will be extended to the maximum  length of 150 m allowing the system to deposit the material and following the irregular contours of the valley.

In 2006 TAKRAF was awarded with a project for a copper mine located in the Region II of Chile which included the design and supply of the following: Extension of existing belt conveyors by approx. 400 m, two new belt conveyor systems with 7,000 and 8,800 tph respectively and 2,000 m length each, a semi-mobile discharge conveyor of 18,000 tph and a semi-mobile surge bin. Likewise the truck dump hoppers of the two existing semi-mobile crushing plant supplied by TAKRAF in 1995 and 2000 have been modified in order to accommodate larger trucks of CAT 797B type. Furthermore the two semi-mobile crushing plants will be relocated by approx. 800m from the current position using multi-wheel trailers.

 

TAKRAF has further been very active with regards to primary crushing plants. At the beginning of 2007 two new orders were received for such units. For the Los Pelambres copper mine located in Region IV of Chile TAKRAF will design and supply a semi-mobile crushing station incorporating a 60 x 113” gyratory crusher and a high volume discharge conveyor. This plant will be supplied on very short delivery and construction schedule and is basically derived from TAKRAF’s proven and existing modular designs.

 

The second award was received from Rio Tinto Coal Australia for the design and supply of equipment on their Greenfield coal mine at Clermont. TAKRAF is in the process of designing and supplying a fully mobile crushing plant on crawlers suitable to crush up to 12,000 tph of overburden. A crawler mounted tripper car and a compact spreader also form part of the works. The overall system includes the equipment mentioned before plus a belt conveyor system. The mobile crushing plant will be fed by a large P&H XPB 4100 rope shovel. The material is received from the shovel into a hopper and transported via an apron feeder to the sizer. The crushed material is then moved by the sizer discharge conveyor and fed via a slewable discharge boom conveyor to a conveyor system and finally to the tripper and spreader. Fig. 3 shows a 3D-model of the mobile unit.

It can also work on different benches using a belt wagon linking it to the face conveyor. In this configuration haul trucks are completely replaced.

 

 

Fig. 3: Mobile crushing plant on crawlers