This article describes the mineral processing and metallurgical testing program conducted for the Luanga PGM + Au + Ni Project as reported in the 2025 Preliminary Economic Assessment.
Report context
The mineral processing and metallurgical testing information presented in this article is derived from Section 13.0 (Mineral Processing and Metallurgical Testing) of the Mineral Resource Estimate Update for the Tonopah West Silver-Gold Project, dated October 22, 2025, with an effective date of August 25, 2025. The report was prepared for Blackrock Silver Corp. The processing sections describe testwork programs conducted in 2022, 2024, and 2025.
Processing route
2022 KCA Bottle-Roll Cyanide Leach Analyses
The 2022 test program involved bottle-roll cyanide leach analyses conducted by Kappes, Cassiday & Associates (KCA). The testwork evaluated the cyanide leaching characteristics of representative mineralized material from the project.
2024 KCA Bottle-Roll Test Work
A second phase of bottle-roll test work was completed by KCA in 2024. This program expanded on the earlier testwork to further evaluate metallurgical response.
2025 AMTEL Deportment Study
A mineral deportment study was completed in 2025 by AMTEL. The study examined the mineralogical distribution of precious metals and associated elements within the mineralization.
Analysis
Section 13.5 of the report provides analysis of the test results. Section 13.6 contains a summary of the metallurgical testing program findings.
Key reported parameters
| Parameter | Unit | Value | Basis |
|---|---|---|---|
| 2022 bottle-roll cyanide leach tests | , | Conducted | KCA testwork |
| 2024 bottle-roll test work | , | Conducted | KCA testwork |
| 2025 deportment study | , | Conducted | AMTEL study |
Project website: https://bravomining.com/luanga-project/luanga-project-highlights/
Technical qualifications
The report is a Mineral Resource Estimate Update and does not include sections on Mineral Reserve Estimates (Section 15.0), Mining Methods (Section 16.0), or Recovery Methods (Section 17.0), as these sections are noted as intentionally omitted from the report. The metallurgical testwork described represents investigative programs rather than definitive process design. No flowsheet details, performance data, economic analysis, or recovery methods are provided in the report.
Source: Mineral Resource Estimate Update – Tonopah West Silver-Gold Project, Nye and Esmeralda Counties, Nevada, USA, effective August 25, 2025, dated October 22, 2025, Section 13.0 Mineral Processing and Metallurgical Testing.
