Três Estradas Phosphate Deposit is located between two hydrographic basins: the Santa Maria River Basin and the Camaquã River Basin. Elevation for the Três Estradas Phosphate Project area ranges from 249m to 367m with a mean elevation of 348m MASL for the deposit area.

The Três Estradas deposit consists of an elongated carbonatite intrusion (metacarbonatite and amphibolite) with a strike of 50° to 60°. The meta-carbonatite and amphibolite form a tightly folded sequence with limbs dipping steeply from 70° to vertical (90°). The surface expression of the intrusion is approximately 2.5 km along strike with a width of approximately 300m. The Late Archean to Early Proterozoic intrusion is intensely recrystallized and metamorphosed to amphibolite assemblages. The carbonatite intrusion is bound mostly by biotite gneiss along with meta-syenite along its northeast and southeast boundaries.

Phosphate mineralization, occurring as the mineral apatite (Ca5(PO4)3(F,Cl,OH)), is the primary mineralization of economic interest at Três Estradas. Apatite is the only phosphatebearing mineral occurring in the carbonatites. At Três Estradas phosphate mineralization occurs in both fresh and weathered meta-carbonatite and amphibolite. Phosphate also becomes highly enriched in the overlying saprolite.

The targeted area consists of an elongated carbonatite intrusion with a strike of 50° to 60° similar to that of the Cerro dos Cabritos Fault. Shear sense indicators sugg ........

Introduction The Três Estradas Project will be an open pit operation utilizing an own mining fleet with a hydraulic excavator 2.0m3 of capacity and 10m3 haul trucks, associated with correspondent ancillary equipment. The mine planning model adopted is a “diluted” model, adding approximately 5% dilution and 95% of recovery to the source model.

The disposal of waste rock will be executed on an area close to the pit. The site shall be adequately prepared to include drainage at its base and channels to direct the flow of water with the aim of aiding geotechnical stability and mitigating the erosion of the stockpiled material. The operation of this phase, in accordance with the ascending method, shall begin during the construction of the heap at the base of this area. Waste rock will be disposed by truck, which will then be uniformly distributed and levelled by an operator using a tractor. The procedure is then repeated, stacking another bank above the original one, while maintaining a ramp for the trucks to be able to access the area.

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