Environmental Assessment
Volume B-3.2
Mine
Geology and Geochemistry
Ambatovy Project
27
January 2006
•
west pit;
•
east pit; and
•
south pit.
In collaboration with technical staff from Dynatec, the major lithologies
represented in each of these facilities were identified during operation and
post closure. These lithologies include ferralite, ferricrete and low magnesium
saprolite (LMS). The various proportions of these lithologies are presented in
Table 3.2-2.
Table 3.2-2 Lithology Proportions in Mine Areas
Composition
Ambatovy
Operational
Post Closure
waste stockpile
100% ferralite
100% ferralite
west pit
90% ferralite/10% LMS
100% ferralite
south pit
90% ferralite/10% LMS
100% ferralite
southeast pit
90% ferralite/10% LMS
100% ferralite
ferricrete stockpile
100% ferricrete
not present
low grade stockpile
100% ferralite
not present
ore stockpile
100% LMS
not present
Analamay
waste stockpile
100% ferralite
100% ferralite
west pit
90% ferralite/10% LMS
100% ferralite
east pit
90% ferralite/10% LMS
100% ferralite
south pit
90% ferralite/10% LMS
100% ferralite
To assign water qualities to each of these facilities, results from short-term leach
testing were used. The leach test conducted was the Synthetic Precipitation
Leaching Procedure (SPLP), which simulates interaction between a solid material
and meteoric water. These results represented the only data available that could
be used to evaluate the environmental stability (i.e., leaching behavior) of the
various lithologies. For ferricrete and LMS, one SPLP result was available for
each lithology. For ferralite, SPLP testing had been conducted on shallow and
deep ferralite samples from Ambatovy and Analamay. It was assumed that the
ferralite in the mine facilities would consist of equal proportions of shallow and
deep ferralite.
Where necessary, SPLP solutions were “mixed” mathematically to represent the
relative proportions of lithologies present in mine facilities. The SPLP results
