They will likely use the existing port at Kribi as it handles...

They will likely use the existing port at Kribi as it handles Capesize Class vessels.

"With its 16-metre draught, this ports infrastructure is presented by experts as one of the most strategic on the entire West African coast. Second phase of construction involves the construction of a second container terminal, with 750 meters of docks, and two other mineral and hydrocarbon terminals." (so, they would be constructing that quickly as the space is there already).

As for the railway "an iron mine in Cameroon and another in Congo that is served by a railway network of 510 km crossing from east to west Cameroon to the deep water port (of Kribi) on Cameroon’s west coast as well as 71 km of rail connecting Nbeba to Mbalam."

So, "the exploitation phase of the deposit, including the construction of the first infrastructure" will include the "mine, Mbalam-Kribi railway, (and) mineral terminal in the port of Kribi."

Hopefully this all pulls together!