The 2011 technical report details metallurgical testwork completed on the COSE project, including gravity concentration and cyanide leaching studies.
Report context
This 20 August 2011 technical report was prepared for Patagonia Gold S.A. and documents the metallurgical testwork program completed by SGS Minerals Services in Santiago, Chile. The report included assays, cyanide leaching bottle tests, and gravity separation tests performed on samples from the COSE project.
Processing route
Sample Preparation and Composition
A total of 70 samples were received and composited into 25 samples at Patagonia Gold’s request. The 25 composite samples and metallurgical tests were summarized in Table 17-1 of the report. SGS in Santiago is ISO-9000 certified.
Screen Fire Assays
A total of 16 coarse residues (95 percent less than 10# ASTM) from composite, high, and mid-grade intervals were analyzed via the screen fire assay technique. This technique determined the size and distribution character of gold mineralization. The technique was designed to concentrate potentially larger gold particles in the coarse fraction sample, given the tendency for gold grains to flatten during grinding. The method enabled semi-quantitative analysis on the potential presence and effects of coarse gold on sample analysis reproducibility of relatively small (50 gram) sample sizes.
Sample preparation involved first milling the coarse reject to 95 percent less than 200# ASTM. The undersize was sieved, weighed, and split into three subsamples, each subsequently fire assayed. The oversize was weighed and subsequently fire assayed, with values over 10 g/t Au determined using a gravimetric finish.
Gravitational Concentration Testing
Three composites weighing between 3.5 to 5 kg were submitted for gravity concentration tests. The samples were milled in a roll crusher to 100 percent less than 10# ASTM (2mm). For each sample, two representative 500 gram sub-samples were obtained using a Knelson concentrator. One sample was retained as a reference sample, and the other was further pulverized to 100 percent below 150# ASTM and analyzed by fire assay to determine the head gold grade. Each sample that returned results over 5 g/t Au was to be re-analyzed by gravimetric finish.
Bottle Roll Tests
A total of 25 composites were submitted for cyanide leaching bottle roll tests. The samples were composited from 70 individual coarse rejects selected from 15 diamond holes taken throughout oxidized, partially oxidized, and non-oxidized portions of fault-hydrothermal breccia hosted and veinlet gold mineralization. The coarse reject composite samples were ground to 95 percent less than 100 microns (# ASTM 150), homogenized, and split into 800 gram pulps. Each composite was tested with a 45 element ICP scan after multi-acid digestion.
Key reported parameters
| Parameter | Design / Proposed | Testwork Data | Basis |
|---|---|---|---|
| Screen fire assay grind size | Not specified | 95% passing 200# ASTM | Proposed for coarse residues |
| Gravity concentration feed size | Not specified | 100% passing 10# ASTM (2mm) | Proposed for 3 composites |
| Bottle roll test grind size | Not specified | 95% passing 100 microns (# ASTM 150) | Proposed for 25 composites |
| Number of samples tested | Not specified | 70 samples composited into 25 | Testwork on diamond drill core |
| Bottle roll sample mass | Not specified | 800 gram pulps | Proposed per composite |
| Gravity sub-sample mass | Not specified | 500 grams per sub-sample | Proposed per composite |
Project website: https://patagoniagold.com/
Technical qualifications
The report presents only proposed metallurgical testwork methods and initial sample preparation procedures. No actual test results, gold recoveries, cyanide consumption data, or processing performance outcomes are reported in the report. The report does not specify a flowsheet, plant design, or final process route. The testwork was conducted on composited samples from 15 diamond holes, limited to the mineralized intervals selected for testing.
Source: Patagonia Gold: COSE Project (NI43-101), 20 August 2011, Section 17.0 Recovery Methods.
Consolidated report summaries
The following former standalone pages about this operation were consolidated here on October 25, 2026. They are retained for source traceability; dates and figures reflect each report’s own effective date and may be superseded by the current information above.
COSE Project — 2012 Technical Report
This report presents a preliminary economic assessment of the Cap Oeste Suroeste (COSE) Project in Santa Cruz Province, Argentina, effective 10 August 2012.
Report context
The COSE Project technical report was prepared for Patagonia Gold PLC with an effective date of 10 August 2012. The report documents a preliminary economic assessment covering mineral resources, mining methods, and recovery methods for the Cap Oeste Suroeste project located in Santa Cruz Province, Argentina. The document includes sections on property description, geology, mineralization, exploration, drilling, sampling, assaying, data verification, mineral resource estimates, mining methods, and recovery methods.
Processing route
Historical and testwork basis
The processing and metallurgical testing section of the report includes gravitational concentration testing and bottle roll tests. Screen fire assays were performed as part of the metallurgical testwork program. The report indicates that preliminary results from these tests informed the proposed process design, though specific numerical outcomes from individual tests are not presented in the available sections.
Proposed process
The proposed process is described in the report under Section 17.5, which outlines the conceptual processing flowsheet for the project. The report does not provide additional details on equipment selection, mass balances, or plant layout within the extract provided.
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Report effective date | 10 August 2012 | Design basis for PEA |
| Project location | Santa Cruz Province, Argentina | Property description |
| Mineral processing testing | Screen fire assays, gravitational concentration, bottle roll tests | Testwork |
| Proposed process | Described in Section 17.5 | Proposed design |
| Resource estimation | PGSA resource model and CAM resource estimation | Historical and review |
| Resource classification | CAM classification system | Resource statement |
Project website: https://patagoniagold.com/
Technical qualifications
The report contains several sections that are referenced in the table of contents but not reproduced in this summary, including mineral resource estimates (Section 14.0), mining methods (Section 16.0), and recovery methods (Section 17.0). Specific resource tonnages, grades, economic parameters, and detailed process design criteria are not available in the current extract. The proposed process design is preliminary in nature, consistent with a preliminary economic assessment, and does not constitute a feasibility study.
Source: NI 43-101 Technical Report Preliminary Economic Assessment Cap Oeste Suroeste (COSE) Project Santa Cruz Province, Argentina, effective 10 August 2012, Sections 1.0, 14.0, 16.0, and 17.0.
