Overview
The Mercedes Mine processing facility employs conventional milling with Merrill-Crowe precious metal recovery, capable of processing approximately 2,000 tonnes per day (tpd). The plant features a comprehensive circuit including three-stage crushing, grinding, cyanide leaching, CCD washing, and specialized recovery systems for gold and silver extraction.
Key Process Stages
- Three-Stage Crushing: Primary jaw crusher (89mm product), secondary cone crusher (19mm product), and tertiary cone crusher (9.5mm product) with screening between stages
- Grinding & Classification: Single 5.03m x 8.84m ball mill (3,430 kW) in closed circuit with 254mm hydrocyclones, achieving P80 of 45µm
- Leaching: Four 9.3m x 9.9m agitated tanks with 24-hour retention time at 50% solids
- CCD Circuit: Four 16.4m diameter thickeners for solution recovery
- Merrill-Crowe Recovery: Zinc dust cementation process handling 155,000 oz gold and 595,000 oz silver annually
- Tailings Treatment: INCO SO2-air cyanide detoxification in two 7.5m x 8.5m reactors
- Refining: Retort furnaces for mercury removal and diesel-fired smelting to produce doré bars
Critical Data
| Parameter | Value |
|---|---|
| Design Throughput | 2,000 tpd |
| Primary Crusher Power | 112 kW |
| Secondary/Tertiary Crusher Power | 224 kW each |
| Ball Mill Power | 3,430 kW |
| Fine Ore Bin Capacity | 3,500 tonnes live (5,275 total) |
| Leach Retention Time | 24 hours |
| Annual Gold Recovery Capacity | 155,000 oz |
| Annual Silver Recovery Capacity | 595,000 oz |
| Detoxification Retention Time | 1.5 hours per tank |
Recent Optimization
In 2021, plant modifications were implemented to recirculate cyanide-containing solution from the CCD circuit to the grinding circuit, reducing overall cyanide consumption while maintaining recovery efficiency.
Technical report and processing history
The following archived source profiles have been consolidated here to preserve the project’s processing history and study context.
Mercedes Gold – Silver Mine — 2024 Technical Report
Mercedes Gold – Silver Mine — 2024 Technical Report
| Company | Bear Creek Mining Corporation |
| Date | 2024 |
| Region | Sonora, Mexico |
| Commodities | Gold, Silver |
| Throughput | 2,000 tpd |
| Status | Operating |
Executive Summary
The Mercedes Mine is an operating underground gold-silver project located in the Cucurpe municipality of Sonora, Mexico, owned by Bear Creek Mining Corporation. Commercial production commenced in 2011, utilizing a 2,000 tpd processing plant equipped with crushing and milling facilities. The deposit is characterized by epithermal, low-sulfidation veins hosted in andesitic volcanic rocks, with significant oxidation extending to depths of 550 meters.
This NI 43-101 Technical Report, effective as of September 30, 2024, provides a comprehensive review of the project’s geology, exploration history, drilling programs, and metallurgical testing. It details the Mineral Resource Estimate, which includes measured, indicated, and inferred categories based on data up to August 2024. The report confirms the mine’s operational status and outlines ongoing exploration targets for resource extension.
Production statistics indicate consistent gold recovery averaging 95.0%, with silver recovery averaging 36.7%. The processing method involves multistage crushing, primary ball milling, and Carbon-in-Pulp (CIP) cyanidation. The QP opinion confirms the reliability of the data and the suitability of the resource estimate for economic extraction.
Website: https://bearcreekmining.com/projects/mercedes/highlights/
Report Date: 2024
Region: Sonora, Mexico
Project Status: Operating
Commodity: Gold, Silver
Throughput: 2,000 tpd
Mine Life:
Mine Type:
Ore type:
Technical report and processing history
The following archived source profiles have been consolidated here to preserve the project’s processing history and study context.
Mercedes Gold-Silver Mine — 2022 Technical Report
Mercedes Gold-Silver Mine — 2022 Technical Report
| Company | Bear Creek Mining Corporation |
| Mine | Mercedes Gold-Silver Mine |
| Date | April 2022 |
| Commodities | Gold, Silver |
Executive Summary
The Mercedes Gold-Silver Mine operates a conventional milling processing facility with a capacity of approximately 2,000 tonnes per day. The plant utilizes a three-stage crushing circuit followed by single-stage grinding and classification with cyclones. Gravity concentration is available but not normally required or used in the current operation.
Precious metal recovery is achieved through agitated cyanide leaching and a Merrill-Crowe recovery circuit. The process includes a Counter Current Decantation (CCD) thickener wash circuit and cyanide detoxification of tailings before the material is sent to the refinery.
In 2021, a minor modification was implemented to the mill flowsheet to optimize cyanide consumption by recirculating solution from the CCD circuit to the grinding circuit. The processing facilities were reviewed by Colin Hardie (QP), confirming the operational status and recovery methods employed at the site.
Reports
- entities/Mercedes_Mine
Website: https://bearcreekmining.com/projects/mercedes/highlights/
Report Date: April 2022
Region:
Project Status:
Commodity: Gold, Silver
Throughput:
Mine Life:
Mine Type:
Ore type:
NI 43-101 Technical Report — Mercedes Gold-Silver Mine
NI 43-101 Technical Report — Mercedes Gold-Silver Mine
| Company | Premier Gold Mines Limited |
| Date | 2021 |
| Region | Sonora State, Mexico |
| Commodities | Gold, Silver |
Executive Summary
The Mercedes Gold-Silver Mine, operated by Premier Gold Mines Limited, is located in Sonora State, Mexico. The facility utilizes conventional milling with Merrill-Crowe recovery for precious metals. The plant has a capacity of approximately 2,000 tpd and includes a three-stage crushing circuit, single-stage grinding with hydrocyclones, and gravity concentration. The ore is processed through agitated cyanide leaching followed by counter-current decantation to recover gold and silver.
The processing circuit features a primary jaw crusher, secondary and tertiary cone crushers, and a single ball mill operating in closed circuit. Gravity concentrate is processed through magnetic separation and shaking tables before smelting. The leach circuit consists of four agitated tanks providing 24 hours of retention time. Tailings undergo detoxification using a variant of the INCO SO2-air process before disposal or paste fill.
The Merrill-Crowe circuit recovers gold and silver via zinc dust cementation, with a capacity of approximately 155,000 ounces of gold and 595,000 ounces of silver annually. The recovered metals are smelted into doré bars off-site for further refining. The mine operates as an underground operation, utilizing tailings for backfill where applicable.
Reports
Website: https://www.juniorminingnetwork.com/junior-miner-news/press-releases/1309-tsx/pg/25180-premier-gold-mines-closes-purchase-of-mercedes-mine.html
Report Date: 2021
Region: Sonora State, Mexico
Project Status:
Commodity: Gold, Silver
Throughput:
Mine Life:
Mine Type:
Ore type:
Mercedes Gold-Silver Mine — 2021 Technical Report
Mercedes Gold-Silver Mine — 2021 Technical Report
| Company | Equinox Gold Corp. |
| Date | 2021 |
| Region | Sonora State, Mexico |
| Commodities | Gold, Silver |
| Throughput | 2,000 tpd |
| Status | Operating |
Executive Summary
This technical report details the recovery methods and processing facilities for the Mercedes Gold-Silver Mine operated by Equinox Gold Corp. The processing plant utilizes conventional milling with Merrill-Crowe recovery of precious metals. The facility is designed to process approximately 2,000 tonnes per day (tpd) of ore. The flowsheet includes a three-stage crushing circuit, single-stage grinding with hydrocyclones, gravity concentration, agitated cyanide leaching, and counter-current decantation (CCD) thickener wash circuits.
The report notes that the chapter is based on a previous technical report completed in April 2018, with minor modifications made in 2020 to allow bypassing the fine ore bin and feeding directly to the grinding mill. The plant includes a refinery for doré production and a tailings detoxification circuit using a variant of the INCO SO2-air process to reduce cyanide levels to environmentally acceptable standards. The Merrill-Crowe circuit has a capacity to process approximately 155,000 ounces of gold and 595,000 ounces of silver annually.
Operational Highlights
- Throughput: 2,000 tpd
- Mine Type: Underground
- Status: Operating
- Processing: Conventional milling, Merrill-Crowe, Cyanide Leaching
Reports
Website: https://www.equinoxgold.com/news/equinox-gold-announces-agreement-to-sell-its-mercedes-gold-mine/
Report Date: 2021
Region: Sonora State, Mexico
Project Status: Operating
Commodity: Gold, Silver
Throughput: 2,000 tpd
Mine Life:
Mine Type:
Ore type:
Mercedes Gold-Silver Mine — 2014 Technical Report
Mercedes Gold-Silver Mine — 2014 Technical Report
| Company | Yamana Gold Inc. |
| Mine | Mercedes Gold-Silver Mine |
| Date | 2014-05-31 |
| Commodities | Gold, Silver |
Executive Summary
The Mercedes Gold-Silver Mine, operated by Yamana Gold Inc., is detailed in this May 2014 NI 43-101 Technical Report. The processing facility utilizes conventional milling with Merrill Crowe recovery for precious metals. The plant design throughput is 1,500 tpd, with actual operations reaching 1,838 tpd in 2013. The mine commenced commercial production in November 2011 and is currently in the operating phase.
The recovery circuit includes crushing, grinding, gravity concentration, leaching, and Merrill Crowe precipitation. Ore is crushed via jaw and secondary/tertiary crushers, then ground in a ball mill. Gravity concentration recovers some gold and silver via bowl concentrators and shaking tables. The remaining slurry undergoes cyanide leaching in agitated tanks followed by carbon column circuits. Pregnant solution is processed through Merrill Crowe for zinc precipitation of gold and silver.
Production data from 2011 to 2014 shows consistent operation with gold recovery rates averaging around 94.4% and silver recovery rates around 32.7%. Reagent consumption includes cyanide, lime, and sodium metabisulphite for detoxification. The mine utilizes underground backfill for tailings management.
Processing Methods
- Crushing: Jaw, Secondary, Tertiary
- Milling: Ball Mill
- Gravity: Bowl Concentrator, Shaking Table
- Leaching: Agitated Tanks, Carbon Column
- Merrill Crowe: Zinc Precipitation
Reports
Website: https://en.wikipedia.org/wiki/Yamana_Gold
Report Date: 2014-05-31
Region:
Project Status:
Commodity: Gold, Silver
Throughput:
Mine Life:
Mine Type:
Ore type:
Mercedes Gold-Silver Mine — 2022 Technical Report
Mercedes Gold-Silver Mine — 2022 Technical Report
| Company | Bear Creek Mining Corporation |
| Mine | Mercedes Gold-Silver Mine |
| Date | April 2022 |
| Commodities | Gold, Silver |
Executive Summary
The Mercedes Gold-Silver Mine operates a conventional milling processing facility with a capacity of approximately 2,000 tonnes per day. The plant utilizes a three-stage crushing circuit followed by single-stage grinding and classification with cyclones. Gravity concentration is available but not normally required or used in the current operation.
Precious metal recovery is achieved through agitated cyanide leaching and a Merrill-Crowe recovery circuit. The process includes a Counter Current Decantation (CCD) thickener wash circuit and cyanide detoxification of tailings before the material is sent to the refinery.
In 2021, a minor modification was implemented to the mill flowsheet to optimize cyanide consumption by recirculating solution from the CCD circuit to the grinding circuit. The processing facilities were reviewed by Colin Hardie (QP), confirming the operational status and recovery methods employed at the site.
Reports
- entities/Mercedes_Mine
Website: https://bearcreekmining.com/projects/mercedes/highlights/
Report Date: April 2022
Region:
Project Status:
Commodity: Gold, Silver
Throughput:
Mine Life:
Mine Type:
Ore type:
NI 43-101 Technical Report — Mercedes Gold-Silver Mine
NI 43-101 Technical Report — Mercedes Gold-Silver Mine
| Company | Premier Gold Mines Limited |
| Date | 2021 |
| Region | Sonora State, Mexico |
| Commodities | Gold, Silver |
Executive Summary
The Mercedes Gold-Silver Mine, operated by Premier Gold Mines Limited, is located in Sonora State, Mexico. The facility utilizes conventional milling with Merrill-Crowe recovery for precious metals. The plant has a capacity of approximately 2,000 tpd and includes a three-stage crushing circuit, single-stage grinding with hydrocyclones, and gravity concentration. The ore is processed through agitated cyanide leaching followed by counter-current decantation to recover gold and silver.
The processing circuit features a primary jaw crusher, secondary and tertiary cone crushers, and a single ball mill operating in closed circuit. Gravity concentrate is processed through magnetic separation and shaking tables before smelting. The leach circuit consists of four agitated tanks providing 24 hours of retention time. Tailings undergo detoxification using a variant of the INCO SO2-air process before disposal or paste fill.
The Merrill-Crowe circuit recovers gold and silver via zinc dust cementation, with a capacity of approximately 155,000 ounces of gold and 595,000 ounces of silver annually. The recovered metals are smelted into doré bars off-site for further refining. The mine operates as an underground operation, utilizing tailings for backfill where applicable.
Reports
Website: https://www.juniorminingnetwork.com/junior-miner-news/press-releases/1309-tsx/pg/25180-premier-gold-mines-closes-purchase-of-mercedes-mine.html
Report Date: 2021
Region: Sonora State, Mexico
Project Status:
Commodity: Gold, Silver
Throughput:
Mine Life:
Mine Type:
Ore type:
Mercedes Gold-Silver Mine — 2021 Technical Report
Mercedes Gold-Silver Mine — 2021 Technical Report
| Company | Equinox Gold Corp. |
| Date | 2021 |
| Region | Sonora State, Mexico |
| Commodities | Gold, Silver |
| Throughput | 2,000 tpd |
| Status | Operating |
Executive Summary
This technical report details the recovery methods and processing facilities for the Mercedes Gold-Silver Mine operated by Equinox Gold Corp. The processing plant utilizes conventional milling with Merrill-Crowe recovery of precious metals. The facility is designed to process approximately 2,000 tonnes per day (tpd) of ore. The flowsheet includes a three-stage crushing circuit, single-stage grinding with hydrocyclones, gravity concentration, agitated cyanide leaching, and counter-current decantation (CCD) thickener wash circuits.
The report notes that the chapter is based on a previous technical report completed in April 2018, with minor modifications made in 2020 to allow bypassing the fine ore bin and feeding directly to the grinding mill. The plant includes a refinery for doré production and a tailings detoxification circuit using a variant of the INCO SO2-air process to reduce cyanide levels to environmentally acceptable standards. The Merrill-Crowe circuit has a capacity to process approximately 155,000 ounces of gold and 595,000 ounces of silver annually.
Operational Highlights
- Throughput: 2,000 tpd
- Mine Type: Underground
- Status: Operating
- Processing: Conventional milling, Merrill-Crowe, Cyanide Leaching
Reports
Website: https://www.equinoxgold.com/news/equinox-gold-announces-agreement-to-sell-its-mercedes-gold-mine/
Report Date: 2021
Region: Sonora State, Mexico
Project Status: Operating
Commodity: Gold, Silver
Throughput: 2,000 tpd
Mine Life:
Mine Type:
Ore type:
Mercedes Mine — 2018 Technical Report
Mercedes Mine — 2018 Technical Report
| Company | Premier Gold Mines Limited |
| Date | 2018-04-18 |
| Region | Nevada, USA |
| Commodities | Gold, Silver |
| Throughput | 2,000 tpd |
| Status | Operating |
Executive Summary
The Mercedes Mine processing facility utilizes conventional milling with Merrill-Crowe recovery for precious metals. The plant operates at a throughput of approximately 2,000 tpd and is designed to process 155,000 ounces of gold and 594,834 ounces of silver annually. The facility includes a three-stage crushing circuit, single-stage grinding with hydrocyclones, gravity concentration, and agitated cyanide leaching followed by counter-current decantation.
The recovery circuit employs a Merrill-Crowe process for gold and silver cementation using zinc dust. Tailings undergo cyanide detoxification via the sulphur dioxide-air process before disposal or backfill. The refinery section processes zinc precipitate and gravity concentrate in retort furnaces and crucible melting furnaces to produce doré bars for off-site refining.
Processing Overview
- Crushing: Three stage (Jaw, Secondary, Tertiary)
- Milling: Ball mill (5.03m x 8.84m)
- Gravity: Bowl concentrator, Shaking table
- Leaching: Agitated cyanide, CCD
- Recovery: Merrill-Crowe
Website: https://www.juniorminingnetwork.com/junior-miner-news/press-releases/1309-tsx/pg/25180-premier-gold-mines-closes-purchase-of-mercedes-mine.html
Report Date: 2018-04-18
Region: Nevada, USA
Project Status: Operating
Commodity: Gold, Silver
Throughput: 2,000 tpd
Mine Life:
Mine Type:
Ore type:
Mercedes Gold-Silver Mine — 2014 Technical Report
Mercedes Gold-Silver Mine — 2014 Technical Report
| Company | Yamana Gold Inc. |
| Mine | Mercedes Gold-Silver Mine |
| Date | 2014-05-31 |
| Commodities | Gold, Silver |
Executive Summary
The Mercedes Gold-Silver Mine, operated by Yamana Gold Inc., is detailed in this May 2014 NI 43-101 Technical Report. The processing facility utilizes conventional milling with Merrill Crowe recovery for precious metals. The plant design throughput is 1,500 tpd, with actual operations reaching 1,838 tpd in 2013. The mine commenced commercial production in November 2011 and is currently in the operating phase.
The recovery circuit includes crushing, grinding, gravity concentration, leaching, and Merrill Crowe precipitation. Ore is crushed via jaw and secondary/tertiary crushers, then ground in a ball mill. Gravity concentration recovers some gold and silver via bowl concentrators and shaking tables. The remaining slurry undergoes cyanide leaching in agitated tanks followed by carbon column circuits. Pregnant solution is processed through Merrill Crowe for zinc precipitation of gold and silver.
Production data from 2011 to 2014 shows consistent operation with gold recovery rates averaging around 94.4% and silver recovery rates around 32.7%. Reagent consumption includes cyanide, lime, and sodium metabisulphite for detoxification. The mine utilizes underground backfill for tailings management.
Processing Methods
- Crushing: Jaw, Secondary, Tertiary
- Milling: Ball Mill
- Gravity: Bowl Concentrator, Shaking Table
- Leaching: Agitated Tanks, Carbon Column
- Merrill Crowe: Zinc Precipitation
Reports
Website: https://en.wikipedia.org/wiki/Yamana_Gold
Report Date: 2014-05-31
Region:
Project Status:
Commodity: Gold, Silver
Throughput:
Mine Life:
Mine Type:
Ore type:
