AMC is proposing a Contract Mining Operation, contracting the key functions of mining, road haulage, port operation and transhipping to experienced contractors with the capability of operating large-scale mining operations in West Africa. Several smaller service contracts will also be let for laboratory services and draft surveying, security, camp village management and medical services.
AMC mining operations will be undertaken by an experienced mining contractor using surface miners as opposed to conventional drill and blast operations.
Surface miners are machines that mill the in-situ material in thin slices. The mined material is broken as it is extracted and depending on the machine type selected, can either be windrowed beside the machine, loaded directly onto trucks using on-board conveyors, or milled in-situ on the pit floor. Surface miner technology is a progression of established technologies, and notably, have an extensive operating history in Guinean bauxite operations.
The mining contractor will use the surface miners to mine the ore and waste, which once milled will then be delineated by grade controllers. Ore that is on-grade will be designated for direct haulage by road haul truck to the port, waste will be hauled by pit trucks to waste stockpiles and off-specification material will be hauled by pit-trucks to in-pit ROM pads, where blending will be performed to build stockpiles until they are at the required grade.
Two of the most common surface miners engaged in other Guinean operations are shown below, both of which are suitable in application on the AMC Project.
AMC will construct a dedicated haul road to transport ore from its mine to its port location. The haul road will traverse the north-western part of Guinea, parallel to the existing national N23 highway, which will include the construction of a 240m bridge over the Kogon River. The haul road from the Koumbia mine to the river port will be unsealed and over 110km in length.
Ore will be loaded onto haul trucks at the mine ‘on grade’ for transport to the river port facility on the Nuñez River. The haulage operations will be carried out by a reputable haulage contractor, with AMC holding a preference for large payload trucks in its operation due to the length of haulage involved. The truck haulage strategy has production contingency in the form of stockpiles at the river port. The stockpiles will be loaded over the dry season to provide a buffer of saleable product over the wet season, where haulage truck productivity is expected to decrease.
An example of the larger payload haul truck options that AMC is pursuing is shown in the image below.
AMC propose to export bauxite using a river port facility along the Nuñez River. The river port will be suitable for the unloading of large payload haul truck deliveries, the stockpiling of bauxite ore and then the loading barges of ~c.7,500t.
The port operations will be contracted out to a reputable and experienced contractor.
Loaded trucks will arrive at the port ‘on grade’ and will be weighed on a dedicated truck weighbridge before unloading ore at the port storage area. Ore will be stockpiled in a logistical fashion, with no requirements for blending of the AMC product at the port. Barges will be loaded in accordance with shipping plans for transhipping.
The barging and transhipping operations will be contracted out to a reputable and experienced contractor. Self-propelled barges will be loaded at the port in dredged berths that allow loading across the full tide cycle of the Nuñez River. Once loaded, the self-propelled barges will travel approximately 100km from the river port to the anchorage location, which lies off the coast of Guinea.
At steady-state production of 11Mtpa, AMC proposes to utilise up to 7 self-propelled barges with a nominal 7,500t cargo capacity.
AMC has a dedicated offshore anchorage location, suitable for the loading of capsize vessels.
A typical self-propelled barge is indicated in the photographs below – the barges in the images are examples of the FAZEL barging technology that could be applied by AMC on the Koumbia Project. These barges are supplied by Luis Dreyfus for another project in Guinea.
At the anchorage location, the self-propelled barges will be unloaded by a transhipment vessel onto ocean-going vessels. Ocean-going vessels will range from 50kt-210kt in size.
Each barge is expected to have a return cycle of around 30 hrs or 1.25 days, including an average travel time of 10 hours (one-way) for transit from port to the anchorage point.