Overview
La Colorada is an open pit gold-silver mine in Sonora, Mexico featuring a 12,000 t/d heap leach operation with carbon adsorption recovery. The facility processes ore through three-stage crushing, heap leaching, and a carbon-in-column adsorption circuit to produce doré bars.
Key Process Stages
- Crushing Circuit: Three-stage crushing to P80 9.5 mm (3/8″)
- Primary: 44″ x 50″ jaw crusher reduces ROM to -250 mm
- Secondary: Two standard cone crushers at 25 mm CSS
- Tertiary: Four short head cone crushers in closed circuit
- Heap Leaching:
- 10m lifts leached for 90 days with 450 ppm NaCN solution
- 10 L/h/m² application rate via drip irrigation
- Lime addition (2-3 kg/t) maintains pH at 10.5
- Double-lined HDPE leach pad with leak detection
- Carbon Adsorption:
- 750 m³/hr cascade carbon-in-column circuit (5 columns)
- Carbon loads to ~5,000 g/t Au+Ag
- Metal Recovery:
- Pressure Zadra stripping at 135°C/450 kPa
- Electro-winning with two electrolytic cells
- Carbon regenerated every 3 cycles at 750°C
- Separate circuit processes carbon from El Castillo/San Agustin mines
Critical Data
| Parameter | Value |
|---|---|
| Throughput | 12,000 t/d |
| Crushing Product Size | P80 9.5 mm |
| Leach Cycle | 90 days |
| Gold Recovery | 67.6% (historical) |
| Silver Recovery | 10.6% (historical) |
| Carbon Loading | ~5,000 g/t Au+Ag |
| ADS Flowrate | 750 m³/hr |
| Cyanide Consumption | 0.5-0.6 kg/t |
| Lime Consumption | 2-3.4 kg/t |
Operational Notes
The facility maintains approximately 15,166 oz Au in inventory (heap, carbon, and solutions). Recent processing of high-grade El Crestón ore (>5 g/t Au) showed slower recovery rates potentially due to coarse gold and electrum presence. The operation includes a mercury retort system for processing San Agustin carbon.
Technical report and processing history
The following archived source profiles have been consolidated here to preserve the project’s processing history and study context.
La Colorada Operations — 2025 Technical Report
La Colorada Operations — 2025 Technical Report
| Company | Minera Pitalla |
| Date | November 2025 |
| Region | Sonora, Mexico |
| Commodities | Gold, Silver |
| Mine Type | Open Pit |
| Throughput | 12,000 t/d |
| Annual Production | 4,380,000 tonnes |
| Status | Operating |
Executive Summary
The La Colorada Operations in Sonora, Mexico, represent an open-pit mining and heap leach project operated by Minera Pitalla. Mining operations ceased in November 2023 but were restarted in January 2025 with the processing of ore from the Junkyard stockpile. The project focuses on the extraction of gold and silver using conventional heap leaching technology. Infrastructure is fully in place to support the Life of Mine (LOM) plan, including open pits, crushing circuits, heap leach pads, and a precious metals smelter.
The processing circuit involves crushing ore to a P80 size of 9.5 mm at a rate of 12,000 tonnes per day. The crushed ore is stacked on a single-use leach pad and leached for 90 days using dilute sodium cyanide solution. Gold and silver are recovered from the pregnant leach solution using a gravity-cascade carbon column train. The loaded carbon is stripped using a pressure-Zadra circuit, and the resulting sludge is smelted onsite into doré bars for shipment.
Environmental management is a key focus, with the mine operating as a zero-discharge facility using lined process water ponds and diversion ditches. All necessary environmental permits have been obtained, including recent approvals for leach pad expansions. The project maintains a strong relationship with the local community through social programs focused on health, education, and urban development, with stakeholder support for continued operations recognized as essential for the town’s wellbeing.
Website: https://miningdataonline.com/property/199/La-Colorada-Mine.aspx
Report Date: November 2025
Region: Sonora, Mexico
Project Status: Operating
Commodity: Gold, Silver
Throughput: 12,000 t/d
Mine Life:
Mine Type: Open Pit
Ore type:
La Colorada Gold/Silver Mine — 2022 Technical Report
La Colorada Gold/Silver Mine — 2022 Technical Report
| Company | Argonaut Resources |
| Mine | La Colorada |
| Date | January 2022 |
| Region | Sonora, Mexico |
| Commodities | Gold, Silver |
| Throughput | 12,000 t/d |
| Status | Operating |
Executive Summary
This technical report details the recovery methods and operational performance of the La Colorada Gold/Silver Mine in Sonora, Mexico. The operation is an open pit mine utilizing a heap leach process with a throughput of 12,000 tonnes per day. Ore is crushed to a P80 of 9.5 mm and stacked on a single-use leach pad where it is leached with dilute sodium cyanide solution for 90 days.
The pregnant leach solution is processed through a gravity-cascade carbon adsorption circuit consisting of five columns. Loaded carbon undergoes pressure-Zadra stripping and electro-winning to produce doré bars. Realized gold recovery stands at 67.6% against an assumed endpoint of 70.0%, while silver recovery is 10.6%. The operation has performed consistently within industry norms regarding recovery, reagent usage, and inventory estimates.
Processing Methods
- Crushing: Jaw crusher and Cone crushers
- Leaching: Heap Leach (Sodium Cyanide)
- Adsorption: Carbon-in-Column (CIC)
- Refining: Zadra Stripping, Electro-winning
Website: https://www.heliostarmetals.com/projects/operations/la-colorada/
Report Date: January 2022
Region: Sonora, Mexico
Project Status: Operating
Commodity: Gold, Silver
Throughput: 12,000 t/d
Mine Life:
Mine Type:
Ore type:
La Colorada Gold/Silver Mine — 2018 Technical Report
La Colorada Gold/Silver Mine — 2018 Technical Report
| Company | Argonaut Gold Inc. |
| Date | 2018 |
| Region | Durango, Mexico |
| Commodities | Gold, Silver |
Executive Summary
The La Colorada mine operates as an oxide ore processing facility utilizing a conventional heap leaching operation. The process involves three-stage crushing to 80% passing 3/8″, followed by stacking on a multi-lift heap leach pad. Irrigation is performed with cyanide solution, and gold recovery is achieved through a conventional ADR (adsorption-desorption-recovery) plant to produce a final doré product. The nominal crushing capacity is 12,000 t/d.
Operational performance data from 2014 to 2017 indicates an overall gold recovery of 62.4% and an overall silver recovery of 13.1%. The heap leach cycle is approximately 90 days, with 85% to 90% of recoverable gold extracted during the first 60 days. The ADR plant processes loaded carbon from La Colorada and is being upgraded to include carbon from Argonaut’s El Castillo and San Agustin mines.
Process operating costs for 2016 were US$3.03/t ore crushed and leached, with lime and cyanide representing over 60% of heap leach operating costs. The facility maintains a solution pH of approximately 10.5 and uses a Zadra pressure strip circuit for carbon regeneration.
Website: https://www.heliostarmetals.com/projects/operations/la-colorada/
Report Date: 2018
Region: Durango, Mexico
Project Status:
Commodity: Gold, Silver
Throughput:
Mine Life:
Mine Type:
Ore type:
