iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
High-grade gold or copper ore contains more of the target metal per tonne than lower-grade material, but that does not automatically make it more profitable. Mine economics depend on how much metal can be recovered and sold, what it costs to mine and process the material, and whether the estimate describes a resource or an economically mineable reserve.
What does ore grade measure?
Grade is the concentration of a target metal in mineralized material. Gold grade is generally reported in grams per metric tonne (g/t); copper grade is commonly reported as a percentage. These units describe different concentrations, so a gold grade and a copper grade cannot be compared by simply looking at their numeric values. The SEC-hosted reserves and resources glossary describes these conventions and the related concept of contained metal.
Contained metal is calculated by multiplying the material’s tonnage by its grade. It is not the same as metal recovered from the ore or ultimately sold: some metal may not be extracted, and the recovery rate depends on the deposit and the processing route.
Why “high-grade” is not a universal threshold
There is no single grade that makes every gold or copper deposit “high-grade” in an economic sense. A grade that can support processing at one operation might not do so at another, because the relevant costs, mineability, ore characteristics, available facilities, by-products and economic conditions differ. Newmont’s 2024 mineral-reserves disclosure explains that cut-off grades vary with such project-specific conditions, including whether the ore can be extracted and processed using the available facilities. Read Newmont’s disclosure.
For that reason, a reported “high-grade” label is most useful when read alongside the project assumptions behind it, rather than treated as a standalone measure or universal benchmark.
How cut-off grade affects mine economics
A cut-off grade is a concentration threshold used to decide how material is treated in the applicable mining plan—for example, whether it is sent for processing or treated as waste. It is an economic and operational decision, not a fixed geological constant. The SEC-hosted glossary describes the material-destination concept, while Newmont explains that cut-off grades can change with prevailing economics, mineability, by-products, processing amenability and available facilities.
Rank #2
- Crush Various Rocks: This jaw stone crusher is suitable for rock sizes under 4.7 inch, even for hard or sticky materials. It can handle calcite, talc, quartz, kaolin, diabase, gangue, shale, basalt, iron ore, quartz sand, calcium carbonate, and bentonite
- High-Efficiency Crushing: Our jaw crusher machine is powered by a 4KW pure copper motor, delivering a fast crushing speed at 1740 RPM. It achieves a strong crushing capacity of 500 to 3000 kg/h, producing fine and uniform particles
- Adjustable Particle Size: By adjusting the discharge setting, you can control the output size within 0.12 to 1 inch. From coarse fragments to fine sand, the rock stone crusher meets different application needs without requiring secondary screening
- Dust-Proof Design: This rock stone crush machine features a drawer-style discharge port with a dust lid to minimize dust and debris splashing during feeding or crushing. This reduces inhalation risks and prevents accidents caused by flying fragments
- Thoughtful Details: Our jaw crusher adopts a stone-crushing process by jaw plate extrusion. The ≥50HRC high-manganese steel jaw ensures long service life, while the steel body keeps the machine stable without shaking. The pure copper motor provides lasting power and efficient crushing
Raising or lowering the cut-off can change which material is included for processing and how much material is classified as ore for a particular plan. The threshold must be interpreted with the assumptions used to set it; a cut-off from one project cannot be transferred to another as a general rule.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
What determines whether grade translates into value?
More grade can mean more contained metal in each tonne, which may increase the potential value of that tonne. The economic result, however, depends on the metal that can be recovered and sold and the costs required to obtain it. Newmont notes that recovery varies by deposit and production process, and identifies grade, recovery, operating costs, waste-to-ore ratio and ore type among the factors affecting reserve sensitivity to price.
- Recovery and ore type: Mineralogy and the processing route affect how much contained metal can be extracted.
- Mining and processing costs: These costs determine how much value remains after material is mined and treated.
- Waste-to-ore ratio and mineability: The quantity of waste that must be moved and the practical ability to mine the deposit affect the economics of accessing ore.
- By-products and facilities: Additional saleable metals and the processing facilities available can affect the threshold for treating material as ore.
- Prevailing economic conditions: Project assumptions affect whether a given grade meets the applicable economic threshold.
Why resource and reserve labels matter
A Mineral Resource estimate and a Mineral Reserve are not interchangeable. A resource describes mineralization with stated geological confidence; it should not automatically be read as material that will be mined. A reserve is the economically mineable portion of qualifying resources after relevant modifying factors and mine planning are applied. The cited technical disclosures describe reserves as incorporating factors such as dilution and losses, and define an Ore Reserve as the economically mineable part of Measured and/or Indicated Mineral Resources. SEC-hosted technical disclosure · ASX technical report.
The SEC-hosted technical disclosure also states that, under its referenced framework, an Inferred Resource cannot be considered when assessing economic viability. That distinction matters when someone cites a high grade from a resource estimate: the grade alone does not establish that the material qualifies as an economically mineable reserve.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How to compare reported grades responsibly
When comparing projects or estimates, keep the context alongside the grade. Useful items to check include:
- Reported grade and units, including whether the figure is for gold, copper or another metal.
- Whether the figure applies to a Mineral Resource or Mineral Reserve, and the estimate’s effective date.
- The stated cut-off grade and the economic assumptions used to set it.
- Recovery assumptions and the processing route.
- Mining method, operating costs and waste-to-ore ratio.
- Ore type and any by-product credits included in the economics.
These details make it possible to assess what a grade implies within a particular project. Without them, “high-grade” describes concentration, not a reliable verdict on profitability.
Best Value
- European Style Large Mortar & Pestle
- 5" tall & 4-3/4" wide at the top. ID size is 3-1/2 at the top and 4-1/2" deep
- Cast Iron
A project-specific cut-off example is not a benchmark
An SEC-hosted technical disclosure for a particular project illustrates a cut-off approach that depends on cost and recovery assumptions. Those figures apply to that project and should not be generalized into a gold or copper grade threshold for other mines. See the project-specific disclosure.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
