This article summarizes the process design and metallurgical testwork reported in the February 22, 2021 preliminary economic assessment for the Los Ricos South project in Jalisco, Mexico, distinguishing planned facilities from historical and laboratory data.
Report context
The February 22, 2021 technical report (effective January 20, 2021) presents a preliminary economic assessment for the Los Ricos South project located in Jalisco, Mexico, at latitude 21° 02’ 45” N and longitude 103° 56’ 08” W. The report was prepared for GoGold Resources Inc. and includes a proposed processing facility, associated infrastructure, and metallurgical testwork programs. This article focuses solely on the processing and recovery methods sections, with no coverage of economic analysis beyond stated report contents.
Processing route
Proposed plant design
The report describes a processing plant designed to treat open pit and underground feed, with the flowsheet presented in section 17.0 of the technical report. The design criteria and plant description are presented as the basis for the preliminary economic assessment, with no claim of construction or operational status.
Primary crushing
Ore is delivered to a primary crushing circuit, where run-of-mine material is reduced to a size suitable for conveying to a crushed feed stockpile. The design specifies a primary crusher followed by a crushed feed stockpile and reclaim system.
Grinding circuit
The grinding circuit comprises a semi-autogenous grinding mill, a ball mill, and associated classification equipment. The design criteria include a target grind size to achieve suitable liberation for downstream leaching, with the circuit configured to process the planned throughput.
Pre-leach thickening and filtration
Following grinding, the slurry reports to a pre-leach thickener and pre-leach filter to adjust pulp density and remove excess water prior to cyanidation. This step is designed to optimize leach performance by controlling cyanide and oxygen concentrations.
Leaching and recovery
The report specifies a carbon-in-leach or Merrill-Crowe recovery process, with the Merrill-Crowe circuit and refinery detailed for gold and silver recovery. A SART (Sulfidization, Acidification, Recycling and Thickening) circuit is included to recover cyanide and base metals, with the report noting the need to manage reactive sulfur and prevent cyanide losses.
Tailings dewatering
Tailings are processed through a dewatering circuit to recover water for recycle to the plant, reducing fresh water demand and minimizing environmental impact.
Ancillary facilities
The plant includes reagent handling and storage, an assay and metallurgical laboratory, water supply, and air supply systems. These are described as supporting infrastructure for continuous plant operation.
Historical processing data
The report references historical metallurgical treatment of Cinco Minas mineralization from 1910–1911, where the deposit was processed using conventional cyanidation and amalgamation methods of that era. No modern performance data is provided from these operations, and the historical records are noted as qualitative context rather than design basis.
Testwork program (2020)
A 2020 testwork program was completed by SGS and reported on November 27, 2020, covering grindability, leaching characteristics, and acid-base accounting. The testwork included:
- Head assays for multi-element analysis
- Grindability testing via SPI®, Bond rod mill, Bond ball mill, and Bond abrasion tests
- Unconfined compressive strength (UCS) tests
- Acid-base accounting (ABA/NAG) testing
The metallurgical testwork investigated cyanidation behavior and recovery, with results supporting the proposed process flow sheet. The report notes that additional testwork and optimization are recommended for the next phase of project evaluation.
Design vs. actual basis
The processing route is presented as a design basis for the PEA, with no actual operating data from a commercial plant at this project. The 2020 SGS testwork provides laboratory-scale evidence of grindability and leach response, while the historical 1910–1911 data is qualitative and not used for design purposes.
Key reported parameters
| Parameter | Value | Units | Basis |
|---|---|---|---|
| Primary crushing | Single-stage jaw crusher | – | Proposed design |
| Crushed feed stockpile | Covered, with reclaim | – | Proposed design |
| Grinding | SAG mill + ball mill, closed circuit | – | Proposed design |
| Target grind size | Not stated in extracted text | µm | Design |
| Pre-leach thickening | High-rate thickener | – | Proposed design |
| Pre-leach filtration | Pressure or vacuum filter | – | Proposed design |
| Leach | Carbon-in-leach or Merrill-Crowe | – | Proposed design |
| Recovery circuit | Merrill-Crowe + refinery | – | Proposed design |
| SART circuit | Included | – | Proposed design |
| Tailings dewatering | Thickening + filtration | – | Proposed design |
| Grindability – SPI® | Reported | kWh/t | 2020 SGS testwork |
| Bond rod mill work index | Reported | kWh/t | 2020 SGS testwork |
| Bond ball mill work index | Reported | kWh/t | 2020 SGS testwork |
| Bond abrasion index | Reported | – | 2020 SGS testwork |
| UCS | Reported | MPa | 2020 SGS testwork |
| Head grade (Au, Ag) | Reported | g/t | 2020 SGS testwork |
| Leach recovery | Reported | % | 2020 SGS testwork |
| Historical treatment (1910–1911) | Cyanidation + amalgamation | – | Historical records |
Project website: https://gogoldresources.com/properties/los-ricos/
Technical qualifications
The following limitations apply to the processing and metallurgical sections of the technical report:
- The process plant design is based on preliminary engineering at a PEA level of confidence; it is not a feasibility study and does not provide a basis for construction.
- The 2020 SGS testwork was performed on limited samples and may not be fully representative of the deposit’s variability.
- Grindability and leach test results are laboratory-scale; scale-up to commercial operation requires further testwork and engineering.
- The historical 1910–1911 metallurgical data is provided for context only and does not constitute a modern process design basis.
- The SART circuit design is based on conceptual considerations for cyanide management; no pilot-scale data is mentioned in the extracted text.
- ABA/NAG testing indicates acid-generating potential, but the report notes that additional geochemical testing is needed to confirm long-term water quality implications.
- The report recommends additional testwork and optimization for the Los Ricos South process, including variability testing, pilot plant runs, and trade-off studies for the SART circuit.
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Source: GoGold Resources Inc., *Preliminary Economic Assessment of the Los Ricos South Project, Jalisco, Mexico*, NI 43-101 Technical Report, Report No. 390, effective date January 20, 2021, report date February 22, 2021, Sections 13.0, 17.0.
