This NI 43-101 technical report presents the feasibility study for the Pan Gold Project located in White Pine County, Nevada.
Report context
The report, with an effective date of November 15, 2011, and signature date of December 19, 2011, was prepared for Midway Gold Corp. The document constitutes a feasibility study-level technical report compliant with National Instrument 43-101 standards for the Pan Gold Project.
Processing route
Ore Sampling and Testwork
Metallurgical testing programs were conducted on ore samples from the Pan Gold Project to characterize the material and evaluate processing options. The testwork included multiple analytical and physical testing methods to support the feasibility-level process design.
Head Assays and Analytical Work
Head assays were performed on representative samples to establish gold grades and characterize the ore composition. XRF analyses provided multi-element geochemical data, while XRD analysis identified the mineralogical phases present in the ore. ICP analysis was conducted for additional trace element characterization.
Physical Testwork
Crushability work and abrasion index testing were performed to evaluate ore hardness and comminution characteristics relevant to crushing circuit design. These tests provided data for equipment sizing and power requirements.
Leach Testing
Static bucket leach tests were conducted on surface samples to provide initial indications of gold extraction behavior. Bottle roll leach tests were performed on finer material to evaluate leaching kinetics and recovery potential under controlled conditions. Column leach tests were conducted to simulate heap leaching conditions at a larger scale, including assay-by-size fraction analysis for gold distribution, test results documenting extraction rates and recovery, percent slump measurements to assess material consolidation, drain down and maximum percolation rate determinations for solution flow characteristics, tailing analysis for final residues, and pregnant solution analysis for gold tenor in process solutions.
Coarse Ore Testing
Coarse ore bottle roll leach tests were conducted specifically on North Pan samples to evaluate leaching behavior at particle sizes more representative of run-of-mine or crushed feed material.
Agglomeration Testing
Agglomeration tests were performed to determine the requirements for fines binding and agglomerate stability, which is critical for maintaining heap permeability and solution flow in heap leach operations.
Carbon Loading Tests
Carbon loading tests were conducted to evaluate the adsorption characteristics of gold from pregnant solution onto activated carbon, providing data for the design of the carbon-in-column or carbon-in-pulp recovery circuit.
Metallurgical Testing Conclusions
The metallurgical testing program provided sufficient data to support the feasibility study process design, confirming that conventional crushing, agglomeration, heap leaching, and carbon adsorption recovery methods are applicable for the Pan Gold Project ore.
Process Description
The proposed processing route for the Pan Gold Project consists of a conventional gold recovery flowsheet. The process begins with primary crushing, followed by secondary crushing to achieve the target particle size. Crushed ore is then agglomerated with cement or other binders to improve heap permeability. Agglomerated material is conveyed and stacked on the heap leach pad in lifts using a stacking system. The heap leach pad is designed with a lined base for solution containment. Dilute cyanide solution is applied to the heap to dissolve gold from the ore. Pregnant solution collected from the heap is processed through an ADR (Adsorption, Desorption, Recovery) gold recovery plant, which includes carbon adsorption, gold stripping, electrowinning, and refining to produce doré gold.
Production Rate and Products
The production rate and product specifications are based on the feasibility study design parameters derived from the metallurgical testwork and mine plan.
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Gold head grade | As reported in head assays | Testwork samples |
| Gold extraction | From column and bottle roll leach tests | Metallurgical testwork |
| Cyanide consumption | From leach testwork | Bottle roll and column tests |
| Crushability index | From crushability work | Physical testwork |
| Abrasion index | From abrasion index testing | Physical testwork |
| Percent slump | From column leach tests | Column testwork |
| Maximum percolation rate | From column leach tests | Column testwork |
| Carbon loading capacity | From carbon loading tests | Carbon adsorption testwork |
| Agglomeration parameters | From agglomeration tests | Agglomeration testwork |
Technical qualifications
The report presents data from metallurgical testing programs, but does not provide complete flowsheet design details beyond the general process description. Specific recovery percentages, final process flowsheet configurations, and detailed equipment specifications are not fully described in the available excerpted sections. The testwork program is described as ongoing at the time of reporting, which may indicate that certain testwork results were pending or incomplete at the effective date.
Source: NI 43-101 Technical Report Feasibility Study for the Pan Gold Project, White Pine County, Nevada, effective date November 15, 2011. Sections 13, 14, 15, 16, and 17.
