ores and pellets heap building in heap leaching of gold depo
2020-08-18 17:01Introduction：ores and pelletsheapbuilding in heap leaching of gold deposits The operation of stacking ores and pelletson the heap table according to the geometric size required by design is called heap building. The operation of the heapbuilding direct
ores and pellets heap building in heap leaching of gold deposits
The operation of stacking ores and pellets on the heap table according to the geometric size required by design is called heap building. The operation of the heap building directly affects the permeability of the whole heap and the uniformity of the particle size distribution, thus affecting the success or failure of the heap leaching. As ore deposits are generally large, it is difficult to change once they are built, so attention must be paid to them at the outset.1、heap building equipment
The equipment for heap building may vary according to the size and environmental conditions of the heap site. For a large heap, dump trucks, loaders or belt conveyors can be used as transport equipment, and bulldozers as leveling equipment. For a small dump, this can be used as a front loader, a small tractor or a human wheel truck as a transport equipment, a bulldozer or an artificial leveling heap.
2、Operation of building a heap
The building of ore heap is different from that of pellet ore. The common method of ore building in China is stratified heap building, which uses the above ore transportation tools to transport ore to one corner of the heap leaching table and form a ramp that can be opened to traffic. The ore truck continues to unload the ore from the ramp to the front end of the heap, and then pushes the ore pile around with bulldozers or manpower, and the ore heap continues to stretch forward and left until it is covered with the whole heap. Formation of the first layer (its height is generally 1.5m). After stacking the first floor. Starting from the origin, the ramp is raised, such as building the second floor until the height of the mine meets the design requirements. Each layer must be mechanically or manually excavated from the surface compacted by the transport vehicle and then stacked in the second layer. After the final layer, the surface of the mine heap must be excavated and loosened before spraying in and out.
The second method of heap building is to transport ore to the heap table with belt conveyer, so as to form several connected small piles, the height of which is higher than the height required by the design, and then bulldozer is used to level the small ore heap. The formation of the design requirements of the ore heap. This method is easy to produce granularity segregation, resulting in even permeability of ore heap, which is disadvantageous to leaching. Therefore, the heap leaching of ore with relatively different raw material size is generally not used, but because the belt conveyer is more convenient to transport ore and save power, this method can be used in the heap leaching field where the particle size difference is relatively small. This method can also be used in the layering and stacking of ore, but when the ore is transported to the heap leaching table by belt conveyer, the ore must be continuously pushed around by bulldozer in time to overcome the phenomenon of grain segregation. This layer after layer heaps the ore to the height of the design requirements.
In the case of pellet heap building, it is best to use a belt conveyer (or loader) to transport a well-maintained mass ore to the heap leaching table to form a small conical ore heap. Then the cone ore pile is pushed forward by loader to the height of 3 meters , The digger is used to build the pile from 3 meters to 4 meters high.(the back type is used to build the pile), the whole pile is built up to the design height and the top of the mine pile needs manual raking.
Many foreign heap leaching sites use belt conveyors with unloading trolleys to transport broken ore or pellet ore to the heap leaching table and install it to a special crawler pile building machine to build the heap. This method can prevent the ore heap from being compacted.
At present, when building a heap, some of the steel pipes or plastic pipes that have been drilled around the heap are buried in the ore heap in the direction of the center around the heap, in order to pass air to the inside of the mine with the help of these pipes. In order to increase the oxygen supply inside the ore heap, the leaching of gold is advantageous.
The height of the heap will affect the leaching rate of gold. When the ore size is small, the heap height should be low, and when the ore size is large, the heap height can be higher. Some foreign unbroken raw ore heap leaching site, its pile up to 46 meters.
