Summary
Project Description
An analysis of alternatives was conducted to compare potential plant site
locations at the mine site, Brickaville and Toamasina. A number of
factors favoured Toamasina as the preferred location. The site was
already disturbed and zoned industrial; good logistics were nearby,
including the port; and it was close to a large source of potential labour.
An offshore refinery was chosen for final metal processing.
The process plant is to be situated on an 80 ha site on the southern
outskirts of Toamasina, about 10 km from the port. The process plant
has an annual capacity of 60,000 tonnes of nickel and 5,600 tonnes of
cobalt over a period of 27 years. The plant includes a leach plant and
associated utility plants. The utility plants include: power, steam and
water plants, a hydrogen plant, a hydrogen sulphide plant, a sulphuric
acid plant, and a limestone and lime plant.
Ore will arrive at the processing plant via the slurry pipeline. The ore
slurry will be treated in autoclaves to extract the nickel and cobalt.
Processing includes first the addition of acid at high temperature to
dissolve the nickel and cobalt. The solid tailings are then separated from
the solution, which contains the nickel and cobalt. This solution will be
neutralized with limestone and then treated with hydrogen sulphide to
precipitate a concentrate of nickel and cobalt. This mixed metal sulphide
is approximately 54% nickel and 5% cobalt. It will be exported for
refining to pure metal products.
Water for the process plant will come from the water used as the
transport medium in the ore slurry pipeline, with makeup as required
from the Ivondro River, delivered to the plant by a buried water pipeline.
The process plant would use about 60 megawatts of electricity and a
large quantity of steam, both to be produced in a coal burning plant.
Additional steam is produced in two sulphur burning sulphuric acid
plants.
The process will require the import of large quantities of sulphur,
limestone and coal. The plant will produce sulphuric acid from the
imported sulphur, which will be consumed at the plant site. The plant will
also produce hydrogen, hydrogen sulphide and lime for use in
processing the ore to the mixed metal sulphide.
Construction of the process plant is expected to take about three years.
There will be a large construction labour force of about 2,800, with the
intent of hiring over 1,100 from the Malagasy population. There will also
be a large operations phase workforce of about 1,150, of which 1,100
will be from the Malagasy population, following extensive training
programs.
January 2006
Ambatovy Project — 27
