Stripping Ratio Calculator: Surface Mining Overburden-to-Ore Economics

How It Works

1. Enter Overburden Data

   Input the thickness of overburden and its in-place density. Treat these as averaged screening prompts until reconciled with drilling, geology, and material data.

2. Enter Ore Body Data

   Input ore-body thickness and density. Grade, dilution, recovery, and resource classification remain outside this screen.

3. Enter Cost Prompts

   Enter commodity price and cost prompts only when they are supported by the project basis. The app does not validate short-ton versus metric-tonne consistency.

4. Review Source Gaps

   Use the stripping ratio, break-even prompt, swell volume, and sensitivity grid as preliminary review flags before block modeling, mine planning, feasibility, or investment reliance.

Built For

• Mining engineers checking transparent stripping-ratio arithmetic before detailed modeling
• Geologists preparing early-stage screening notes while keeping resource/reserve gaps visible
• Mine planners separating simple ratio arithmetic from pit optimization and phase design
• Financial reviewers stress-testing price and cost prompts before qualified feasibility work
• Environmental teams estimating preliminary waste-rock scale before reclamation and permit review
• Operators comparing local cost prompts while preserving source and qualified-review warnings

Features & Capabilities

Volumetric Stripping Ratio

Screens waste volume divided by ore volume using the entered average geometry and consistent volume units.

Weight-Based Ratio

Converts volumes to tonnage using entered density prompts. Contract and reporting bases still need project review.

Break-Even Prompt

Uses the classic textbook break-even stripping-ratio form from entered price and cost prompts; it is not a pit-depth decision.

Sensitivity Grid

Shows how the break-even prompt moves with +/-20 percent price and cost changes.

Swell Factor Prompt

Converts bank volumes to loose-volume prompts using local screening swell rows that require project verification.

PDF Export

Exports inputs, outputs, source warnings, and source pointers for review packets, not feasibility reports or investor materials.

Assumptions

• Waste and ore volumes are estimated from geological cross-sections or block model data.
• Material densities (bank and loose) are uniform within each material type.
• Overburden removal cost and ore mining cost are expressed as cost per unit volume or weight.
• Ore value is based on a single commodity price and assumed recovery rate.
• Pit slope angles are stable and do not require additional waste removal for buttressing.

Limitations

• Does not model pit optimization (Lerchs-Grossmann or floating cone) or select pit limits.
• Ignores haul distance, road grade, and truck cycle time variations with pit depth.
• Does not account for selective mining losses or dilution at the ore/waste contact.
• Commodity price volatility over the mine life is not modeled - uses a single price scenario.
• Does not include reclamation costs, royalties, taxes, sustaining capital, or discounting in the break-even prompt.

References

• SME Mining Engineering Handbook, 3rd Edition - surface mining economics.
• Hustrulid, Kuchta, and Martin, Open Pit Mine Planning and Design.
• CIM/SME guidelines for economic evaluation of mineral projects.
• Whittle Consulting - pit optimization and strategic mine planning references.

Frequently Asked Questions