Processing
A foundation in turning mineral-bearing material into a saleable product, including historic mine tailings.
Grade is only the starting point
Grade describes concentration in a defined material. Recovery measures how much of the valuable component reaches the chosen product. Product grade and recovery answer different questions; neither alone establishes profitability.
Match the process to mineralogy
| Stage | Purpose | Evidence needed |
|---|---|---|
| Characterisation | Identify where valuable and harmful components occur. | Representative sampling, assays, mineralogy and variability. |
| Liberation and separation | Use an appropriate combination of crushing, grinding and physical or chemical separation. | Testwork showing recovery, product quality and consumption. |
| Product finishing | Dewater, dry, refine or otherwise prepare the saleable form where needed. | Moisture, impurities, customer specification and qualification. |
| Residue and water management | Manage remaining solids, water and reagents. | Site-specific environmental, storage and operating requirements. |
Read the source: USGS · Recovery from mine waste ↗
Assess tailings as a project
Historic processing can leave valuable material behind, but old workings and stored tonnage are not proof of an economic project. Reprocessing needs representative data on geometry, grade, mineralogy, variability, access and ownership.
Progress from characterisation to bench testing and, where justified, pilot work. Evaluate product acceptance, recovery, energy and water demand, residues, rehabilitation, capital and operating costs together.
Understand the reporting language
A Mineral Resource and an Ore Reserve are different classifications. Converting a resource to a reserve requires consideration of relevant technical, economic and other modifying factors under the applicable reporting framework.
A historical estimate, a laboratory result and a compliant public resource statement are not interchangeable. Record the author, date, methodology, limitations and intended use of each piece of evidence.
Read the source: JORC · Reporting and classification ↗
Continue learning
Read the source: USGS · Recovery from mine waste ↗ · JORC · Reporting and classification ↗
Educational overview. Apply the current rules, contract and cargo-specific requirements to each shipment or project; this is not a substitute for specialist advice.