The Lavrinha Deposit which is closely linked to the Ernesto Deposit has been interpreted as gold-rich quartz veins and veinlets with coarse grained pyrite occurring along shallow-dipping structure. The main difference with Ernesto is the position of the mineralization in the metasedimentary sequence. Gold mineralization is located along quartz boudins in highly sericitized rock and plunges to the north.

The Ernesto-Lavrinha Deposits consists of gold- rich quartz veins and veinlets occurring along a relatively thick, shallow-dipping structure at the base of the metasedimentary sequence and within altered sulphidic horizons in overlying meta- arenite units. The basal structure is interpreted to be a low-angle detachment fault that has been folded and faulted together with the overlying stratigraphy. Gold mineralization is located along asymmetrical anticlines and synclines that plunge gently to the north and are cut by NW and NE- trending narrow faults. The gold mineralization occurs in three zones: Lower Trap, Middle Trap and Upper Trap.

The Upper Trap, which is widely developed in the Lavrinha Deposit, occurs in metapelitic rocks (hematite sericite schist) in dilation zones of the intensely deformed synclinal troughs. The Upper and Intermediate traps share similar alteration and mineralization suites.

The Ernesto-Lavrinha Deposits are described as detachment-style gold deposits, where typically gold mineralization is associated with lo ........

Lavrinha open-pit mine is a part of the Ernesto/Pau-a-Pique complex located in the southwest of Mato Grosso state, near Pontes e Lacerda in Brazil which consists of the following gold deposits: the Lavrinha open-pit mine (“Lavrinha”), the Ernesto open-pit mine (“Ernesto”), the Pau-a-Pique underground mine (“Pau-a-Pique” or “PPQ”), the Japones open-pit mine, the Nosde open-pit mine, and the near mine open-pit prospects of Bananal North and Banal South.

The Lavrinha Property is contiguous to Ernesto and does not contain any infrastructure.

The overall strip ratio for Lavrinha is 12.6:1 with mining conducted 365 days per year by a contractor. The contract is full service and includes providing all mining equipment, drilling, blasting, loading, hauling and maintenance. Total material movement rates for the LOM range from 15,000 to 25,000 tpd.

Conventional truck and hydraulic shovels will be utilized. Four excavators, supported by three front-end loaders, will load a fleet of ten 38- tonne trucks and five 25-tonne trucks. Ore will be transported to the primary crusher and run-of-mine (“ROM”) pad, and waste material will be hauled to a nearby waste rock storage facility.

Primary crushing:
The first step to obtain gold is crushing. The crusher used in the plant is a jaw crusher, which is fed through a vibrator feeder (220-FE-001) with the support of a wheel loader.

The vibratory feeder (220-FE-001), with opening in the 100 mm grille, removes the ore with solids mass flow with a rate of 280 t/h. The ore retained in the grille of this feeder is discharged into the jaw crusher (220-CR-001). Both the passing material in the vibrating feeder grid and the material in the crusher discharge are collected and transported to the crushed ore’s silo through the conveyor belts (220-CV-001/002), which are equipped with a metal detector (220-MD-001) and a metal extractor (220-EX-001).

Related to environmental compliance in the crushing stage, it has a dust reduction system, in all transfer. In the crushing stage only, physical processes are performed and so sodium cyanide is not used.

Grinding/ Milling and Gravimetric concentration:
The grinding/ milling circuit is intended to receive the crushed ore, with a top size of 101.6 mm and generate a product granulometrically compatible for the CIL step, with size 80% passerby in a mesh of 0.106 mm. To carry out the comminution process in the SAG mill, 5" steel balls are used.

The replacement of the SAG mill’s balls is done directly in the mill feed, through the hopper (330-BN-003). The balls are discharged, with the support of electric hoist (330-CN-003) in box (330-XM-001) and later in the hopper.

The resumption of crushed ore for grinding, in the solids mass flow with a rate of 205 t/h, is carried out by the feeders (260-FE-002/003/005) and by the conveyor belt (260-CV-003) equipped with a scale (260-SL-004).

The crushed ore (new feed) feeds the SAG mill (330-ML-001), which has dimensions of 19' x 19' (5.7 x 5.7 meters) and installed power of 2.5Mw (Megawatts). The trommel (opening 10 x 20 mm) removes the pebbles from the discharge, which return to the SAG mill through the conveyor belts, 330-CV-004 and 260-CV-003, equipped with a scale (330-SL-002), constituting the part of the circulating load. The passerby in the trommel is collected in the box (330-PB-001) where process water is added to adjust the percentage of solids in the pulp (up to 52% solids) to feed 5 hydro cyclones with 500 mm in diameter, this feeding is performed by pumps (330-PP001/001R). Hydro cyclones classify the pulp through centrifugal force into overflow and underflow.

The underflow of hydro cyclones is collected in the distribution box (330-DI-001), where half of the flow feeds by gravity the scalping sieve (360-SC-002), with opening in the 2 mm screen and the other half returns to the SAG mill, constituting another part of the circulating load. In the scalping sieve the retained material returns to the SAG mill, constituting one more part of the circulating load, while the passerby feeds the centrifugal concentration (360-CG-001). The centrifugal concentration aims at the recovery of free and relatively coarse gold, and it is predicted that 0.16 t/h (dry base) of heavy concentrate (approximately 0.14% of the feed’s plant) are transferred to the intensive leaching area. The light fraction of the centrifugal concentration returns to the SAG system, constituting another part of the circulating load. In short, the circulating load consists of the following flows: retained in the trommel, 50% of the underflow of the cyclones, retained in the scalping sieve and tailings of the centrifugal concentration.

The overflow of hydro cyclones feeds the thickening step.

The drainage of the area is carried out by the pumps (330-PS-002/003).

In the grinding stage, only physical processes are performed with a reduction from 101.6 mm to 0.106 mm and sodium cyanide is not used.

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