The Goliath Gold Complex NI 43-101 Technical Report and Prefeasibility Study, effective February 22, 2023, describes a proposed processing plant designed to treat material from the Goliath, Goldlund, and Miller deposits in the Kenora District of Ontario.
Report context
This technical report and prefeasibility study, with an effective date of February 22, 2023, was prepared for Treasury Metals Inc. The report covers the Goliath Gold Complex located in the Kenora District, Ontario, Canada, and includes mineral processing and metallurgical testing, recovery methods, and process design for the proposed operation.
Processing route
Overall Process Design
The proposed processing plant is designed to treat ore from three deposits: Goliath, Goldlund, and Miller. The overall process design incorporates a conventional gold recovery flowsheet consisting of crushing, grinding, gravity recovery, intensive cyanidation, leach and adsorption, cyanide destruction, and tailings thickening.
Crushing and Ore Stockpiling
The proposed crushing circuit includes primary crushing followed by ore stockpiling ahead of the grinding circuit. The design provides for surge capacity between the crushing and grinding stages.
Grinding Circuit
The grinding circuit is designed to reduce the ore to a target grind size for gold liberation. The report indicates that recovery models were developed based on the grind size, with specific recovery models for Goliath and Miller, and separate models for Goldlund.
Gravity Recovery Circuit
The proposed gravity recovery circuit includes centrifugal concentrators designed to recover coarse gold prior to leaching. This circuit is integrated with an intensive cyanidation reactor for processing gravity concentrate.
Intensive Cyanidation Reactor
Gravity concentrate is directed to an intensive cyanidation reactor for high-concentration leaching of the gravity gold concentrate.
Leach and Adsorption Circuit
Following gravity recovery, the ore slurry is directed to a leach and adsorption circuit. This circuit employs cyanidation leaching with carbon-in-pulp or carbon-in-leach adsorption for gold recovery from solution.
Cyanide Destruction
The proposed flowsheet includes a cyanide destruction circuit using sodium metabisulphite (SMBS) and copper sulphate to treat the leach tailings prior to thickening and deposition.
Tailings Thickening
Tailings from the cyanide destruction circuit are thickened in a tailings thickener to recover process water and produce a thickened tailings stream for disposal.
Carbon Acid Wash, Elution and Regeneration Circuit
Loaded carbon from the adsorption circuit is processed through an acid wash, elution, and regeneration circuit. Gold is stripped from the carbon in the elution circuit, and the regenerated carbon is returned to the adsorption circuit. Gold-bearing solution from elution is directed to the gold room for recovery.
Gold Room
The gold room receives gold-bearing solution from the elution circuit. Gold is recovered through electrowinning or precipitation, and the resulting gold sludge is smelted into doré bars using fluxes.
Reagent Handling and Storage
The proposed plant includes reagent handling and storage facilities for hydrated lime, sodium cyanide (NaCN), copper sulphate, sodium metabisulphite (SMBS), sodium hydroxide (NaOH), hydrochloric acid (HCl), flocculant, activated carbon, oxygen, and gold room smelting fluxes.
Services and Utilities
Plant and instrument air systems are included in the design. Electrical power supply is specified for the process plant and associated infrastructure.
Water Supply
The design includes fresh water and process water supply systems, as well as gland water supply for pump seals.
Key reported parameters
| Parameter | Units | Basis |
|---|---|---|
| Plant throughput | Not specified | Proposed design |
| Grind size | Not specified | Testwork basis |
| Gold recovery – Goliath and Miller | % | Recovery model from testwork |
| Gold recovery – Goldlund | % | Recovery model from testwork |
| Gravity recovery | Not specified | Proposed design |
| Leach residence time | Not specified | Proposed design |
| Cyanide detoxification | mg/L | Testwork basis |
| Tailings thickener underflow density | % solids | Proposed design |
| Reagent consumptions | kg/t | Proposed design |
Technical qualifications
The report contains specific limitations identified by the qualified persons. Metallurgical testwork was conducted on samples from the Goliath, Goldlund, and Miller deposits, and the results were used to develop recovery models. The report notes that the testwork included comminution testing, extended gravity recovery gold (E-GRG) testing, leaching testing, oxygen uptake testing, and cyanide detoxification testing. Thickening tests including flocculant scoping, static settling tests, dynamic thickening, and rheology testing were performed. Deleterious elements were evaluated as part of the testwork program. The recovery models are differentiated for Goliath and Miller versus Goldlund, and for Goldlund Zone 1 versus other Goldlund zones. The report indicates that historical testwork was conducted prior to the prefeasibility study testwork program.
Source: Goliath Gold Complex NI 43-101 Technical Report and Prefeasibility Study, effective February 22, 2023, Sections 13 and 17.
