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Brazil

Chapada Mine

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Overview

Mine TypeOpen Pit
StatusActive
Commodities
  • Copper
  • Gold
  • Silver
Mining Method
  • Truck & Shovel / Loader
Production Start2007
Mine Life2051
SnapshotChapada production is entirely from Chapada, with the Chapada Main and Corpo Sul pits in operation. These pits are planned to eventually join into a single pit and extraction of the Sucupira deposit is planned as an additional series of pushbacks.

The Suruca open pit mining area includes Suruca Oxide gold Mineral Reserves and Suruca Sulfide gold Mineral Resources. The Suruca deposit is located approximately 7 km northeast of the Chapada open pit.
Related AssetSuruca Project

Owners

SourceSource
CompanyInterestOwnership
Lundin Mining Corp. 100 % Indirect
Mineração Maracá Indústria e Comércio S.A. (operator) 100 % Direct
Mineração Maracá Indústria e Comércio S.A. is a wholly-owned indirect subsidiary of Lundin Mining that owns the Chapada Mine.

Contractors

ContractorContractDescriptionRef. DateSource
Enaex Blasting Eneax is the explosives supplier and carries out blasting operations. Oct 10, 2019
MTSUL Construções Mining Oct 10, 2019
unawarded or unknown Power supply The Chapada mine is connected to the National Electric Grid through a privately owned 85.4 km long 230 kV transmission line connected to the Energias de Portugal electric substation at the city of Itapaci, Goiás. The current power demand at Chapada is approximately 50.0 MW. Dec 31, 2023

Deposit type

  • Porphyry
  • Epithermal
  • Skarn

Summary:

Several genetic models have been suggested for Chapada, including: (i) a deformed and metamorphosed porphyry-type copper-gold deposit (Richardson et al., 1986; Oliveira et al., 2015), (ii) a deformed and metamorphosed volcanogenic disseminated sulphide deposit (Silva and Sá, 1986; Kuyumjian, 1989), and (iii) epithermal copper-gold deposit overprinted by metamorphic remobilization (Kuyumjian, 2000).

The most accepted metallogenetic model for Chapada is a metamorphosed porphyry model associated with skarn system. The magmatic hydrothermal system was generated in island arc stage setting (approximately 884 Ma to 879 Ma) and posteriorly overprinted by remobilization of orogenic fluids during Brasiliano events (ca. 630 Ma).

The porphyry, skarn, and epithermal system can be separated into three distinct mineralization styles, based on hydrothermal alteration and metal association:
- Copper-Gold Porphyry System (Chapada Corpo Principal, Corpo Sul, and Sucupira);
- Gold (Silver-Lead-Zinc) Distal Skarn (Suruca);
- Copper-Gold Proximal Skarn (Suruca SW).

The Chapada and Suruca deposits are located in the metavolcano-sedimentary sub-unit of Mara Rosa Sequence.

UPPER METAVOLCANO-SEDIMENTARY LAYER (A LAYER). The A layer is defined by interlayering of several lithotypes, such as garnet-biotite- quartz schist (same as in the metasedimentary layer), amphibole-quartz schist, biotite-quartz schist, biotitegneiss, amphibole-biotite gneiss, and metatuff.

The A layer hosts the mineralization at Baruzinho, Chapada SW, and Suruca.

METAVOLCANIC LAYER (B LAYER).
The B layer is defined by a 50 m to 200 m thick layer of biotite-quartz schist, biotite-gneiss, and amphibole-biotite gneiss (same as described in the metavolcano-sedimentary layer).

Three intrusive facies are observed: metaquartz diorite porphyry, metadiorite porphyry, and intermediate metaplutonic rock. The metaquartz diorite porphyry represents early- to inter- mineral porphyry stocks, which are related to coppergold mineralization at most orebodies of the Chapada deposit. The metadiorite is interpreted as inter- or late-mineral porphyry stocks and occur throughout the Chapada and Suruca deposits. Only at Suruca, however, are they the host rock of both copper-gold and gold only mineralization. The intermediate metaplutonic lithotype represents late-mineral porphyry stocks that crosscut the copper-gold mineralization at the Baru, Sucupira, Corpo Sul, and Santa Cruz orebodies.

SYN-TECTONIC TO POST-TECTONIC INTRUSIONS.
The syn-tectonic and post-tectonic intrusions are represented by metadiorite, bimodal deformed dikes, and pegmatites.

The metadiorite is deformed medium grained diorite with salt-and-pepper texture, locally named as Chapada Diorite.

Bimodal syn- to post-tectonic dikes are observed throughout the Chapada and Suruca deposits with an average thickness of one metre to ten metres.

WEATHERING EVENT.
The mine area is covered by a 30 m thick lateritic profile composed of a coarse saprolite, mottled zone or argillic zone, lateritic duricrust, and pisolitic soils (products of alteration of duricrust) from bottom to top.

The Chapada deposit lithologies were grouped in “litho-structural domains” to assist mine operations. These domains are classified based on lithological relationships, intensity of hydrothermal alteration, and intensity of weathering.

MINERALIZATION.
CHAPADA.
Copper is principally present as chalcopyrite with minor amounts of bornite. Fine grained gold is closely associated with the sulphide mineralization and was likely to be contemporaneous with the copper.

The mineralization at the Chapada deposit is represented predominantly by sulphide disseminations along foliation plans (or axial surfaces of folds) and, to a lesser extent, in small massive concentrations in the hinges of folds. In general, the ore is formed predominantly by chalcopyrite, pyrite and magnetite, where chalcopyrite-magnetite (magnetite rich ore) and chalcopyrite-pyrite (pyrite rich ore) are the prevailing associations, in which pyrite is the most abundant mineral, magnetite (including hematite, ilmenite and rutile) is subordinate, and galena, bornite, sphalerite, and molybdenite are rarely reported.

The copper mineralization and grade are somewhat better in the central zone of the deposit along the anticline axis than in the surrounding anticlinal limbs, however, copper mineralization is pervasive over a broad area.

SURUCA.
The gold at Suruca is related to folded quartz veins/veinlets with sericitic and biotite alteration, rather than high sulphide concentrations. The second generation quartz veins/veinlets with sulphides (sphalerite + galena + pyrite), carbonates, and epidote also host gold which is related to zinc. The copper mineralization in the Suruca SW displays same features as Chapada, with sulphide disseminations and sulphides associated with stockwork quartz veinlets. In general, Suruca SW mineralization is formed predominantly by chalcopyrite and pyrite, with subordinate sphalerite and molybdenite.

Mineralization predominately pre-dates deformation so the gold (Suruca) and copper- gold (Suruca SW) zones are associated with skarn features, however, some structurally controlled features are also observed.

Reserves at December 31, 2023

Mineral Reserves are estimated using open pit discard NSR cut-off values of $5.80/t and $6.80/t for the Chapada open pit and Suruca gold oxides respectively.

The Chapada and Suruca copper-gold Mineral Resource estimates are reported within a conceptual pit shell at an open pit discard NSR cut-off value of $5.80/t. For the Suruca copper-gold, NSR cut-off value of $6.80/t was used for oxide (heap leach) and sulphide portion, and $11.42/t for oxide (carbon-in-leach). For the Suruca gold only Mineral Resource estimates, NSR cut-off values of $6.80/t for oxides and $11.42/t for mixed and sulphide were used.

Mineral Resources are reported inclusive of Mineral Reserves.
CategoryOre TypeTonnage CommodityGradeContained Metal
Probable Stockpiles 136,472 kt Copper 0.18 % 245 kt
Probable Stockpiles 136,472 kt Gold 0.11 g/t 477 koz
Proven & Probable In-Situ (OP) 472,314 kt Copper 0.24 % 1,150 kt
Proven & Probable In-Situ (OP) 493,329 kt Gold 0.14 g/t 2,241 koz
Indicated Stockpiles 136,472 kt Copper 0.18 % 245 kt
Indicated Stockpiles 136,472 kt Gold 0.11 g/t 477 koz
Measured & Indicated In-Situ (OP) 920,684 kt Copper 0.24 % 2,169 kt
Measured & Indicated In-Situ (OP) 1,079,007 kt Gold 0.16 g/t 5,704 koz
Inferred In-Situ (OP) 54,230 kt Copper 0.22 % 119 kt
Inferred In-Situ (OP) 59,227 kt Gold 0.14 g/t 268 koz

Mining Methods

  • Truck & Shovel / Loader

Summary:

Chapada is a traditional open pit truck and excavator operation that has been in continuous operation since 2007. Production is currently entirely from Chapada, with the Chapada Main and Corpo Sul pits in operation. These pits are planned to eventually join into a single pit and extraction of the Sucupira deposit is planned as an additional series of pushbacks.

The Chapada open pit has current ultimate design dimensions of approximately 8 km along strike, up to 1.5 km wide, and 380 m deep.

Mine operations are carried out with a fleet of rigid frame haul trucks combined with a variety of diesel-powered hydraulic excavators and front-end loaders as the primary loading equipment. A fleet of large diesel-powered blast hole rigs are employed for production drilling. Blasting is required for all rock types except for unconsolidated material at surface.

The Suruca open pit mining area includes Suruca Oxide and Suruca Sulfide gold Mineral Reserves. The Suruca deposit is located approximately 7 km northeast of the Chapada open pit and final pit dimensions will be approximately 2 km along strike and approximately 1 km wide.

The Chapada LOM plan is based on the Mineral Reserves and a processing rate of up to 24.0 Mtpa with the ore stockpile to be processed intermittently throughout the mine life. The current mine life is 22 years plus an additional seven years at the end of the mine life for processing the remainder of the ore stockpile.

Comminution

Crushers and Mills

TypeModelSizePowerQuantity
Gyratory crusher 1
Jaw crusher Metso Nordberg C160 1
Pebble crusher Metso Nordberg HP800 600 kW 2
Sizer MMD 1000 1
SAG mill 10.4m x 5.8m 12500 kW 1
Ball mill 7.3m x 12.2m 12500 kW 1
Vertical mill / Tower Metso VTM-1000-WB 748 kW 1

Summary:

PRIMARY CRUSHING
Ore is delivered from the mine by haul truck to one of two parallel lines of primary crushers. The first line consists of a primary gyratory crusher located adjacent to the pit. Ore is dumped directly into the crusher feed bin. Oversized material is broken using a hydraulic rock breaker. The discharge of the gyratory crusher is then conveyed to the feed bin of an MMD 1000 Sizer (Sizer) for secondary crushing. The ore is transferred from the bin with an apron feeder and passed over a vibrating grizzly feeder which feeds the Sizer. Grizzly undersize bypasses to the Sizer product conveyor and, along with the Sizer product, is conveyed to the crushed ore stockpile. The Sizer limits the production rate as it has a lower capacity than the gyratory crusher. Consideration has been given to bypassing the Sizer to increase production.

The second system consists of a Metso C160 jaw crusher. Ore is dumped directly into the crusher feed bin. The ore is drawn from the bin with an apron feeder to a vibrating grizzly feeder which feeds the jaw crusher. Crusher product and grizzly undersized material are combined on the jaw crusher discharge conveyor and transferred the crushed ore stockpile.

CRUSHED ORE STOCKPILE AND RECLAIM
The crushed ore stockpile is a conical stockpile with three draw points using apron feeders. Ore is drawn from the stockpile by three apron feeders onto the SAG mill feed conveyor, which delivers the ore directly into the SAG mill feed chute.

PRIMARY AND SECONDARY GRINDING
The grinding circuit consists of a primary 10.4 m x 5.8 m long EGL SAG mill with a dual pinion 12,500 kW drive (2 x 6,250 kW) for primary grinding. The SAG mill discharges onto a horizontal double deck vibrating screen. The top deck has 12 mm openings and the bottom has six millimetres openings. The screen oversize pebble is conveyed to two HP800 pebble crushers with 600 kW drives. The pebble is reduced from the typical critical size of 38 mm x 75 mm, to approximately 12 mm and then returned by conveyor to the SAG mill feed conveyor. The screen undersize slurry reports to the primary cyclone feed pumpbox. The slurry is then pumped to a cyclopac consisting of six 813 mm diameter hydrocyclones (five operating). The cyclone underflow slurry flows by gravity to the 7.3 m x 12.2 m long EGL ball mill with a dual pinion 12,500 kW drive (2 x 6,250 kW) drive, while the cyclone overflow flows to the rougher flotation feed distribution tank. The primary cyclone underflow can be routed to either the ball mill or SAG mill, allowing the SAG mill to be operated in either open or closed circuit as required. The ball mill discharges into the secondary cyclone feed pumpbox from which it is pumped to the ball mill cyclopac consisting of nine 813 mm diameter cyclones (seven operating). The cyclone underflow reports to the ball mill feed chute and the cyclone overflow flows by gravity to the rougher flotation feed distribution tank.

Processing

  • Crush & Screen plant
  • Flotation
  • Dewatering
  • Filter press

Summary:

The Chapada concentrator is designed to treat copper sulphide ore at a nominal rate of 65,000 tpd for a total of 24.0 Mtpa.

ROUGHER FLOTATION
The rougher flotation circuit consists of two lines of rougher-scavenger flotation cells. Each line has a bank of five 160 m3 Dorr-Oliver Eimco tank flotation cells that have been retrofitted with Outotec mechanisms (Outotec TankCell and FloatForce), consisting of two rougher cells, one middling cell and two scavenger cells in series.
- The concentrate from the rougher cells flows to the concentrate regrind feed pumpbox.
- The cyclone underflow feeds the vertical regrind ball mill.
- The concentrate from the middling cell can either report the concentrate regrind or to the primary cyclone feed pumpbox in the grinding circuit.
- The concentrate from the scavenger cells is pumped back to the primary cyclone feed sump in the grinding circuit.
- The scavenger tailings are pumped to the TSF.

CONCENTRATE REGRINDING
The concentrate regrind circuit consists of a Metso Vertimill, VTM-1000-WB, with a 748 kW drive in closed circuit with a bank of four 20 in. hydrocyclones (two operating).

CLEANER FLOTATION
- The cyclone overflow from the concentrate regrind circuit flows to the new SFR cleaner scalper cells.
- The concentrate from the SFR scalper cells is final concentrate grade and is pumped to the concentrate thickener.
- The cleaner scalper tailings are pumped to a bank of six 21.5 m3 conventional cleaner flotation cells.
- The cleaner tailings are pumped to a new bank of four Staged Flotation Reactor (SFR) cleaner scavenger flotation cells.
- There is an existing bank of two 160 m3 Wemco tank cells that currently operate as cleaner scavenger cells or pyrite cells in parallel with the new SFR cleaner scavengers.
- The concentrate from the cells is pumped to the feed of the cleaner flotation cells. The tailings from both banks of cells are pumped the final tailings pumpbox and then to the TSF.
- The cleaner concentrate is pumped to a final cleaner column flotation cell. The tailings from the column cell are pumped to the concentrate regrind circuit and the concentrate is pumped to the final concentrate thickener.

CONCENTRATE THICKENING, FILTRATION, AND STORAGE
The final concentrate is thickened to approximately 60% solids in a 13 m diameter x 3 m high Dorr Oliver Eimco thickener. The thickened concentrate is then pumped from the thickener underflow to an 11 m diameter x 11 m high concentrate storage tank. The concentrate is then pumped to a Larox PF60/72 M145 filter press, with a capacity of approximately 45 tph, located in the concentrate storage building above the concentrate stockpile. The pressure filter reduces the concentrate moisture to approximately 8% before discharging it onto the stockpile below. The concentrate is then loaded onto trucks and transported to the Port of Vitoria for shipping.

In 2018, a study and basic engineering report were commissioned, which combined the information gained from several studies regarding process plant upgrading, optimization and, ultimately, the expansion of the processing facilities from the current capacity to approximately 32.0 Mtpa. This expansion has not been advanced but options for mine and mill expansions are being evaluated in parallel with the significantly increased exploration efforts. These expansion options will include the need to relocate some elements of the processing plant and site infrastructure in order to mine the Sucupira mineralization. The Company completed a prefeasibility study for expansion of the Chapada operation in 2022, including the debottlenecking of the existing processing facilities to increase throughput from the current level to up to 25.2 Mtpa and the construction of a new processing line to duplicate production for a combined throughput of up to 50 Mtpa. The optimization study will advance to feasibility in 2023 seeking to achieve up to 26 Mtpa while the study for the new processing line will be put on hold pending further definition and update of the Mineral Resources and Mineral Reserves of Chapada.

For Suruca, run of mine ore, which consists of oxide and sulfide mineralization, will be processed separately. The oxide ore will be processed using conventional heap leaching technology; and the sulfide ore will not be processed.

Recoveries & Grades:

CommodityParameter202320222021202020192018201720162015
Copper Recovery Rate, % 80.278.680.486.282.782.479.877.280
Copper Head Grade, % 0.260.260.270.30.310.310.310.340.37
Copper Concentrate Grade, % 22.222.523.724.123.924.324.5
Gold Recovery Rate, % 55565659.759.463.35756.956.8
Gold Head Grade, g/t 0.150.160.180.240.240.260.280.30.33
Gold Concentrate Grade, g/t 8.9610.413.815.515.415.515.3

Water Supply

Summary:

Process water is pumped from a water pumping station located in the water reservoir adjacent to Dike II in the TSF area to the process water reservoir at the process plant. A booster pump station is located outside of the TSF in the reclaim water pipeline. Each station is equipped with a set of three submersible centrifugal pumps operating in parallel for a combined capacity of 7,600 m3 /h.

Fresh/make-up water is supplied from two sources, the Rio dos Bois pump station, and the Cava Central mine. The Rio dos Bois pump station consists of two parallel pipelines fed by six submersible pumps connected to the water lines by a valved header which allows each pump to supply either pipeline. A submersible pump is connected to each of the headers by a flexible hose.

The Cava mine pits are the primary source of fresh/process water and have been used exclusively for the past several years. Surface and ground water drains into and collects in the bottom of the pit. Water is pumped from the pit using submersible pumps and a booster pump station to transfer the water to the water reservoir in the tailings dam. From there it is pumped to the process water reservoir at the process plant.

The water storage capacity in the bottom of the mine pits is used to maintain the overall site water balance. Water can be pumped from one pit to the other and to the TSF and process plant, providing flexibility in controlling the site water balance.

Water Balance
• approximately 1,500 mm of rainfall per year;
• annual consumption is 3.4M m³/year and with contemplated expansions could increase to 7.0M m³/year, which is within the permitted level;
• recycled water constitutes roughly 86% of process requirements;
• the open pits are the primary source of make-up water. Storage capacity in the bottom of the mine pits is used to maintain the overall site water balance;
• process water is pumped from the water reservoir in the Tailings Storage Facility (TSF) area to the reservoir at the plant;
• permitted to withdrawal up to 10.3M m3 /yr from local Bois river though not typically required and have not done so in last two years.

Production

2019 operating results are presented for the period of Lundin Mining's ownership, from July 5th, 2019 to December 31st, 2019.
CommodityProductUnits2024202320222021202020192018201720162015
Copper Metal in concentrate t 43,000-48,000 ^45,719 45,739 52,019 50,038 30,529 58,604 57,742 52,390 59,421 
Gold Metal in concentrate oz 55,000-60,000 ^59,000 68,000 76,000 87,000 54,000 121,003 119,852 107,301 119,059 
Silver Metal in concentrate oz 258,000258,000257,000242,000144,000252,748259,444274,533
Copper Concentrate kt 243242216243
^ Guidance / Forecast.

Operational metrics

Metrics202320222021202020192018201720162015
Daily milling capacity 65,000 t65,000 t65,000 t65,000 t65,000 t
Plant annual capacity 24 Mt24 Mt24 Mt24 Mt24 Mt23.4 Mt22 Mt
Ore tonnes mined 29,508 kt26,319 kt37,294 kt29,386,000 t18,240,000 t33,787,816 t34,163,445 t17,223,764 t19,959,943 t
Tonnes milled 22,233 kt22,752 kt24,121 kt19,192,000 t11,911,000 t22,929,227 t23,000,557 t19,779,013 t19,896,894 t
Daily milling rate 62,820 t
Waste 31,305,991 t32,832,383 t27,751,926 t24,784,951 t

Production Costs

CommodityUnits20242023202220212020201920182017
Credits (by-product) Copper USD -1.15 / lb   -1.2 / lb   -1.17 / lb   -1.46 / lb   -1.26 / lb  
Cash costs (sold) Copper USD 3.42 / lb   3.28 / lb   2.22 / lb   1.75 / lb   1.84 / lb  
Cash costs Copper USD 1.51 / lb   1.54 / lb  
Cash costs Gold USD 334 / oz   334 / oz  
Cash costs Silver USD 3.38 / oz  
Cash costs (sold) Copper USD 2.05 / lb ^ **   2.27 / lb **   2.08 / lb **   1.05 / lb **   0.29 / lb **   0.58 / lb **  
All-in sustaining costs (AISC) Copper USD 1.76 / lb   1.74 / lb  
All-in sustaining costs (AISC) Gold USD 399 / oz   385 / oz  
All-in sustaining costs (AISC) Silver USD 3.88 / oz  
All-in sustaining costs (sold) Copper USD 3.24 / lb **   3.36 / lb **   1.75 / lb **   0.84 / lb **   0.97 / lb **  
^ Guidance / Forecast.
** Net of By-Product.

Financials

Units2024202320222021202020182017
Capital expenditures (planned) M USD 110  
Capital expenditures M USD 72.3  104.7  52.3  38.6   44.1   46.7  
Sustaining costs M USD 72.3  104.7  52.3  38.6   35.2   27.9  
Revenue M USD 461.2  477.9  567.4  445.4   475.4   425.4  
Gross profit M USD 80.4  41.4  229.4  228.5  
Operating Income M USD 206.2   172  
After-tax Income M USD 55  25.3  135.8  102.6  

Heavy Mobile Equipment

Ref. Date: October 10, 2019

SourceSource
HME TypeModelSizeQuantityLeased or
Contractor
Crane Terex AC 250-1 1
Crane Sany STC800 80 t 1
Crane Mercedes Benz Madal MD-300 1
Dozer Caterpillar D6M 2
Dozer Caterpillar D9 3
Dozer Caterpillar 834 1
Dozer Caterpillar D6T 2 Leased
Dozer Caterpillar D9T 3 Leased
Dozer Caterpillar D10 3 Leased
Drill Epiroc D65 1 Leased
Drill Sandvik D45 2
Drill Atlas Copco ROC L8 RC 1
Excavator Liebherr R 9250 3
Excavator Caterpillar 320D 1
Excavator Liebherr 964 1
Excavator Volvo EC950 2 Leased
Excavator Hyundai 220 2 Leased
Excavator Caterpillar 374 1 Leased
Excavator Hitachi EX5500 3 Leased
Excavator Hitachi EX2500 2 Leased
Excavator Volvo EC220 1 Leased
Grader Caterpillar 16H 3 Leased
Grader John Deere 1 Leased
Grader Caterpillar 16M 3
Loader Caterpillar 950 2 Leased
Loader Caterpillar 944 2
Loader Caterpillar 993 2
Truck (dump) Caterpillar 785C 13
Truck (dump) Caterpillar 777G 6
Truck (dump) Volvo A60H 4 Leased
Truck (dump) Caterpillar 740 15 Leased
Truck (dump) Mercedes Benz Atego 1725-42 2 Leased
Truck (dump) Mercedes Benz 2726 K 6x4 2 Leased
Truck (dump) Komatsu 730 5 Leased
Truck (haul) Komatsu 930 12 Leased
Truck (service) Mercedes Benz 2729 4 Leased
Truck (service) Scania P420 6X4 1 Leased
Truck (service) Mercedes Benz 1
Truck (service) Mercedes Benz 1
Truck (water) Mercedes Benz AXOR 3344 2 Leased
Truck (water) Mercedes Benz 2 Leased
Truck (water) Mercedes Benz 2729 3 Leased
Truck (water) Caterpillar 777 1 Leased
Truck (water) 4 Leased

Personnel

Mine Management

Job TitleNameProfileRef. Date
Director of Environment & Sustainability Marcos Lewin LinkedIn May 30, 2024
Director of Operations Paulo Godoy LinkedIn Mar 5, 2024
Maintenance Manager Alfredo Boggi Duarte LinkedIn Mar 5, 2024
Plant Operations Manager Alderney Moreira LinkedIn Mar 5, 2024
Supply Chain Manager Alex Marques Sousa LinkedIn Mar 5, 2024

EmployeesContractorsTotal WorkforceYear
923 2022
924 2021
798 2020
752 1,340 2,092 2019
510 1,076 1,586 2018

Aerial view: