Mining Intelligence and News

Cerro Bayo Mine

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Mine TypeUnderground
StatusCare and Maintenance
  • Silver
  • Gold
Mining Method
  • Blast Hole Stoping
Production Start... Lock
SnapshotEquus completed its acquisition of the Cerro Bayo Project from Mandalay Resources Corporation.

The project includes an operational flotation processing plant which under Mandalay commenced processing of low-grade stockpiles in late February 2021, having been on care and maintenance since 2016.

Equus continued processing until suspension of stockpile processing on the 17 October 2022.

During the quarter ended June 2023, Equus continued the restructure of its Cerro Bayo project in Chile following the suspension of the stockpile processing announced on 17 October 2022, placing the processing infrastructure on care and maintenance whilst continuing exploration at the Cerro Bayo Project.


Compañia Minera Cerro Bayo Ltda. (operator) 100 % Direct
Equus Mining Ltd. 100 % Indirect
Following shareholder approval obtained on 27 November 2021, Equus completed its acquisition of the Cerro Bayo Project from Mandalay Resources effective 1 December 2021. The acquisition provided a near-zero cash outlay to acquire 100% of the Cerro Bayo Project including the Project´s mining properties, resources, and mine infrastructure, including the now fully operational plant.

Deposit type

  • Vein / narrow vein
  • Epithermal


Epithermal Au and Ag mineralization at Cerro Bayo is contained in veins, stockworks, and breccias. The deposits show multiple stages of mineralization and display open-space filling and banding, typical of lowsulfidation style epithermal mineralization. Mineralogy is complex and is associated with alteration assemblages that suggest at least three types or stages of precious depositional environments.

The principal epithermal gold-silver mineralization event with local bonanza grades is hosted mainly in NNW and N-S to NNE structural trends, such as the Cerro Bayo, Cascada and Coigues Este (in the Laguna Verde sector) veins.

This event was predated by a more likely mesothermal event with silver, gold and base metal mineralization hosted in arcuate N-S to NNE veins and tectonic breccias. This style of mineralization is only known to exist in the Laguna Verde sector and is interpreted to be a result of igneous intrusions, doming, and subsequent collapse. A third mineralizing event is interpreted to coincide with the emplacement of a porphyritic stock and related apophyses at Rodados Colorados, which is characterized by a porphyry-style alteration pattern. This includes moderately extensive propylitic alteration with chlorite, epidote, disseminated cubic pyrite, and specular hematite. Structures contain gangue dominated by calcite with locally abundant oxides and relict pyrite.

Epithermal mineralization is characterized by Au and Ag associated with minor copper, lead, and zinc. Over 90 major veins have been identified to date within the property. Vein mineralogy consists of predominantly quartz with a minor, but complex, sulfide mineral suite and accessory gangue minerals. The veins pinch and swell following pre-mineral faults and fractures. Exposed strike lengths vary from 300 to 2,200 m and widths vary from 0.5 to 5.0 m, with local pods up to 7 m wide. The control of mineralization is mostly structural. The mineralizing fluids were channeled along pre-mineral faults or fracture zones that were in-filled during successive hydrothermal pulses, locally punctuated by syn-mineral fault movement. Lithology also plays a role in mineral control. Brittleness and plasticity of the host units control the width of the veins, the degree of development of sheeted zones, and variations in the dip of the veins due to refraction. Mineralized shoots typically are sub-horizontal, extending up to 1 km or more in length, with a vertical extent of as much as 200 m.



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Mining Methods


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Crushers and Mills


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Silver Concentrate kt  ....  Subscribe2.96.17.3
Silver Payable metal koz  ....  Subscribe7951,7312,546
Silver Metal in concentrate koz  ....  Subscribe
Gold Payable metal oz  ....  Subscribe5,90913,79222,572
Gold Metal in concentrate oz  ....  Subscribe
Gold Equivalent Payable metal oz  ....  Subscribe17,02137,27856,965

Operational metrics

Daily processing capacity  ....  Subscribe1,650 t
Annual processing capacity  ....  Subscribe
Tonnes processed  ....  Subscribe156,727 t396,508 t456,128 t
Ore tonnes mined  ....  Subscribe154,542 t383,860 t447,481 t
Daily production capacity  ....  Subscribe31 t of silver concentrate

Production Costs

Cash costs Gold Equivalent USD  ....  Subscribe
Cash costs Silver USD 14.1 / oz **  
All-in costs Silver USD 27.1 / oz **  
** Net of By-Product.

Operating Costs

UG mining costs ($/t milled) USD 61.1  52.9  
Processing costs ($/t milled) USD  ....  Subscribe  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe  ....  Subscribe


Capital expenditures M USD  ....  Subscribe 2.7   9.6  
Revenue M USD 25.4  
Pre-tax Income M USD -40.5  
After-tax Income M USD -39.6  

Heavy Mobile Equipment


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Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Oct 31, 2023
....................... Subscription required ....................... Subscription required Subscription required Oct 31, 2023
....................... Subscription required ....................... Subscription required Subscription required Oct 31, 2023

EmployeesContractorsTotal WorkforceYear
...... Subscription required ...... Subscription required ...... Subscription required 2018
...... Subscription required ...... Subscription required ...... Subscription required 2016
...... Subscription required ...... Subscription required ...... Subscription required 2015

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