The Paragominas bauxite deposits are developed on a 10,000km2 plateau, situated 50 m to 150 m above the drainage-incised valley floors. The average altitude does not exceed 150 m in the plateaus. The Miltônia 3 (M3) and Miltônia 5 (M5) gibbsitic bauxite deposits have formed by deep tropical weathering of the Ipixuna Formation. The bauxite layer forms a nearly continuous tabular body, less than 5 m thick, but extending 20km north–south, and as much as 8km east–west, beneath the plateau surface. Prolonged weathering and oxidation of aluminum-rich sediments allowed the formation of gibbsite, an aluminum hydroxide, which can occur in a microcrystalline, porcelain-like form (amorphous bauxite), or as fine-grained euhedral crystals that occasionally reach 1 mm in size. Minerals within the deposit display either ‘detrital’ or ‘secondary’ character. Minerals that are ‘detrital’ were originally deposited as part of the host water-borne sediment (e.g., quartz and anastase); those that are ‘secondary’ are weathering products of kaolinite and feldspar. The geological profile of the Miltônia deposit has eight horizons, with lateral variation in thickness to characterize the following lenticular horizons: Clay Overburden (CAP), Nodular Bauxite (BN), Crystallized Nodular Bauxite (BNC), Ferruginous Laterite (LF), Crystallized Bauxite (BC), Crystallized/Amorphous Bauxite (BCBA), Amorphous Bauxite (BA), and Variegated Clay rocks of the District pertain to the Itapecuru Group (south and c ........

Bauxite from Paragominas is mined using strip mining technology. It is sorted and crushed for transportation as a slurry through a 240-kilometer-long pipeline, then refined into alumina at Alunorte.

Hydro’s only operated mine, the Paragominas bauxite mine, is located in the state of Pará in northern Brazil. It requires the removal of vegetation, topsoil and overburden to extract bauxite deposits from 8 to 12 meters underground and disturbs relatively large areas.

Hydro uses strip mining in Paragominas, a technique that avoids the formation of an overburden stockpile. Thus, all overburden moved for mining purpose is used to reconstruct the topography of the strip previously mined, prior to rehabilitation of the mined areas. Part of the overburden (laterite) is also used for paving roads and for raising the heights of existing tailing dams and constructing new ones.

The mining operation has two major conditions to consider: a high stripping ratio (7.6 in volume) and a high rainfall, thus it is necessary to have a mining system that minimizes the cost of waste stripping and aids selectivity.

The main objective to introduction of surface miner (SM2500 Wirtgen) in the Paragominas bauxite Mine is to reduce operating costs and investments, replacing the equipment of current mining system (CAT D11 dozers in scarification process and recovery the pit, CAT 365CL excavator in ore loading and CAT 160M in the square after scarifi cation) with a ........

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