The Yellow Giant property forms part of the Banks Island Mineral Property, for which a November 2011 technical report describes historical and recent metallurgical testwork and a proposed gravity separation processing route.
Report context
This technical report, dated November 23, 2011, addresses the Banks Island Mineral Property located on Banks Island, British Columbia. The report includes a preliminary economic assessment and covers the Yellow Giant property, which comprises the Tel, Discovery, and Bob zones. The mineral processing section (Section 17.0) presents a proposed gravity separation plant design based on historical metallurgical test programs conducted between 1973 and 1988, supplemented by 2011 heavy liquid separation and pressure oxidation testwork.
Processing route
Proposed gravity separation plant
Section 17.0 of the report describes a mineral processing flowsheet based on gravity separation. The proposed plant design relies on evidence from 2011 heavy liquid separation testing and 1988 flotation testing. The plant is intended to produce a gravity concentrate, with assumptions for gravity concentrate grade and recovery derived from the testwork.
Heavy liquid separation evidence (2011)
The 2011 metallurgical test program included heavy liquid separation testing on samples from the Tel Central and Tel Main zones. These tests were conducted to evaluate the potential for gravity pre-concentration of gold-bearing material prior to further processing.
Flotation testing evidence (1988)
A 1988 metallurgical test program examined flotation of a bulk sulphide concentrate, whole ore cyanidation, and cyanidation of the bulk flotation concentrate. The report also notes that a Bond mill grindability index test and solid/liquid separation tests were completed during this program.
Gravity concentrate assumptions
The report states that gravity concentrate assumptions were developed from the combined evidence of the 2011 heavy liquid separation tests and the 1988 flotation testing program. Specific concentrate grade and recovery values are not detailed in the processing section summary.
Additional testwork (1973, 1986, 1987)
Historical test programs include a 1973 cyanidation test, a 1986 gravity concentration test, and a 1987 gravity scalping test. Results from these programs are presented in Section 13.0 of the report but are not directly incorporated into the proposed gravity separation plant design described in Section 17.0.
Pressure oxidation and cyanidation testing (2011)
The 2011 test program also included pressure oxidation and cyanidation testing. Sample preparation and results for this work are documented in Section 13.9 of the report.
Key reported parameters
| Parameter | Units | Basis | Value |
|---|---|---|---|
| Plant type | , | Proposed design | Gravity separation plant |
| Metallurgical testwork period | , | Historical | 1973–1988 |
| Metallurgical testwork period | , | Current | 2011 |
| Heavy liquid separation tests | , | 2011 testwork | Tel Central and Tel Main samples |
| Flotation test | , | 1988 testwork | Bulk sulphide concentrate |
| Cyanidation test | , | 1973 testwork | Whole ore |
| Gravity concentration test | , | 1986 testwork | Gravity separation |
| Gravity scalping test | , | 1987 testwork | Gravity scalping |
| Bond mill grindability index | , | 1988 testwork | Completed |
| Pressure oxidation test | , | 2011 testwork | Completed |
| Cyanidation test | , | 2011 testwork | Completed |
Project website: https://www.cbc.ca/news/canada/british-columbia/banks-island-gold-benjamin-mossman-trial-1.7147971
Technical qualifications
The mineral processing section (Section 17.0) presents a proposed plant design that is based on historical testwork data and 2011 heavy liquid separation testing. No operating data from a commercial-scale gravity separation plant at the Yellow Giant property is presented in this report. The report does not include results from a pilot plant or continuous operation. Metallurgical testwork was conducted on limited samples from specific zones (Tel Central, Tel Main) and may not be representative of the entire deposit. The report does not provide detailed flowsheet diagrams, equipment specifications, or mass balance data for the proposed gravity separation plant.
Source: Technical Report & Preliminary Economic Assessment on the Banks Island Mineral Property, November 23, 2011, Sections 13.0 and 17.0.
