London Mining has started production of iron ore from its Marampa operation in Sierra Leone.
The ore achieved validated plant design specifications of 65% Fe and 3.5% silica, and the first shipment is scheduled later this month.
The plant's first phase capacity is expected to increase by 11% to 4Mtpa based on further plant optimisation.
The company intends to spend a total of $234m on the prject, which is an 11% rise compared with the original $210m.
Bateman Engineering will undertake the bankable feasibility study programme for the phase 2A expansion, which is expected to be complete by next year.