The 2013 Technical Report for the Union Reefs Gold Project sets out updated Mineral Resource and Reserve estimates, processing considerations, and recommendations for further exploration and development, drawing on historical mining data and recent technical studies.
Report context
The Union Reefs Gold Project Technical Report was prepared in July 2013 for Crocodile Gold Corp in compliance with Canadian Securities Administrators National Instrument 43-101 (Form 43-101F1). The report covers Mineral Resources and Reserves for the Union Reefs Gold Project, part of the Northern Territory Operations Group, and includes the Prospect, Crosscourse, Orinoco, Lady Alice, Esmeralda, Union North, Union South and Millars/Big Tree deposits. The report was compiled using historical exploration and mining data, internal technical memoranda, drill logs, assay reports, and input from Cube Consulting Pty Ltd, which reviewed and generated resource estimates for the Crosscourse, Prospect and Orinoco deposits.
Processing route
Historical processing context
The report does not present a new or modified processing flowsheet. Historical mining in the Union Reefs area produced gold from the Crosscourse deposit, which contributed over 80% of the gold from the Union Reefs area. The report states that a combination of mineralization from the Crosscourse and Prospect deposits could supply long-term mill feed to the Union Reefs mill, indicating that the existing milling infrastructure is considered available for future processing. However, no detailed process design, equipment specifications, or recovery data are provided in the report.
Proposed processing considerations
The report indicates that the Union Reefs mill is expected to process ore from the Crosscourse and Prospect deposits. The report recommends an exploration ramp into the Prospect deposit to better understand the mineralized structure and configuration, and to assist in determining an appropriate mining method, ore recovery, and expected dilution. This suggests that processing feed characteristics are contingent on further geological understanding and that no final processing route has been selected.
The report also notes that the Prospect deposit displays a relatively consistent high-grade set of parallel mineralized structures, which may have implications for feed grade variability and mill scheduling. The report does not provide mass pull, grade-recovery curves, or processing rates.
Testwork and metallurgical data
The report does not describe any metallurgical testwork, comminution testing, gravity recovery tests, cyanide leach tests, or other processing-related laboratory work. No reagent consumption, grind size, or recovery data are reported. The report does not specify whether the ore is free-milling or refractory, nor does it describe any historic plant performance in detail.
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Gold grade units | g/t | Reported throughout |
| Tonnage units | Metric tonnes | Reported throughout |
| Gold metal units | Troy ounces | Reported throughout |
| Coordinate system | UTM WGS-84, Zone 52L | Report-wide |
| Deposit depth extent (Prospect) | At least 400 m | Drilling-defined |
| Drill spacing (Prospect test section) | 25 m centers over 200 m | Historical drilling |
| Esmeralda deposit distance from Union Reefs | 7 km to the south | Reported |
| Monetary values | Australian Dollars ($A) | Unless otherwise stated |
Project website: https://www.northernminer.com/company/025049695/
Technical qualifications
The report notes that the Crosscourse deposit’s cross faulting is not well understood and requires further structural studies. The geophysical signature of the mineralized structures is not well defined, and no significant IP/resistivity surveying has been completed over the area. Cultural features may interfere with future surveys. The plunge direction and grade distribution of the Prospect deposit need further understanding, and it is felt that further drilling will not adequately address these issues. The down-plunge extension of the Crosscourse deposit is considered a potentially significant exploration target, but drilling from surface is not economically feasible, so ramp-based drilling is recommended. The report also states that Inferred Mineral Resources must be excluded from estimates forming the basis of feasibility or other economic studies, and that confidence in Inferred resources is insufficient for meaningful application of technical and economic parameters.
Source: Union Reefs Gold Project, Technical Report, July 2013, Crocodile Gold Corp.
