Mining Technical Report Review Checklist

Summary box

• Read the report out of order. Start with the qualified person's conclusions and the sensitivities, then work backwards into the assumptions that produced them.
• Seven items carry nearly all the risk: sample security, data verification, metallurgy, resources, reserves, economics and the QP's own conclusions.
• Absent disclosure is the strongest signal in the document. The codes mandate specific items precisely because omitting them is how projects get oversold.
• Check the effective date before anything else. A three-year-old study on a producing mine describes a different orebody.
• Compare against the study it supersedes. The delta, and whether the company explains it, tells you more than either document alone.

How to read it

A technical report is written in the order the work was done. That is the wrong order to read it in.

Read in this sequence:

1. Effective date and study stage. How old, and PEA / initial assessment, pre-feasibility or feasibility?
2. Item 25 — Interpretation and Conclusions. The QP's own view, in their words, including risks. Short, candid, and almost never read first.
3. Item 22 — Economic Analysis, specifically the sensitivity tables, not the base case.
4. Item 14 and 15 — Resources and Reserves. Category split, cut-off, price.
5. Item 13 — Metallurgy. The largest hidden swing factor.
6. Items 11 and 12 — Sample security and data verification. Foundational integrity.
7. Everything else, as context.

Reading the summary first anchors you to the promotional framing. Reading the conclusions first anchors you to what the author actually believes.

Stage and vintage

• [ ] Effective date recorded, and depletion since if the mine is producing
• [ ] Study stage identified: PEA / initial assessment, PFS, FS
• [ ] Capex accuracy band appropriate to the stage (roughly ±30–50% PEA, ±20–30% PFS, ±10–15% FS)
• [ ] A more recent reserve or resource statement checked for in the latest AIF, 10-K, 20-F or annual report — companies restate more often than they refile
• [ ] Prior study located for comparison

Authorship and independence

• [ ] Qualified Person or Competent Person named for each section
• [ ] Their experience relevant to this deposit type, not just to mining generally
• [ ] Professional association named and in good standing
• [ ] Independence status stated where required
• [ ] Under S-K 1300, note whether the QP is an employee — permitted, but a reason to read Items 11–13 harder
• [ ] Consent on file (JORC public reports)

Under NI 43-101, a qualified person must, among other things, hold a relevant degree, have "at least five years of experience in mineral exploration, mine development or operation, or mineral project assessment," have experience relevant to the subject matter of the project, and be in good standing with a recognised professional association.

Item 11 — Sample preparation, analyses and security

• [ ] Certified reference materials, blanks and duplicates used
• [ ] Insertion rates stated
• [ ] Failures investigated and re-assayed, not just noted
• [ ] Laboratory named, with location and its relationship to the issuer
• [ ] Chain of custody described
• [ ] Historical (pre-acquisition) data treated separately from data the QP controls

Item 12 — Data verification

• [ ] QP states what they personally checked
• [ ] Limitations paragraph read in full
• [ ] Twinned holes or pulp re-assays where historical data is material
• [ ] Any inability to verify historical data disclosed and quantified

"The QP was unable to verify drilling completed prior to 1998" is a materially different report from one where the QP re-assayed pulps. Both are legitimate; only one supports confidence.

Item 13 — Metallurgy

• [ ] Number of samples tested
• [ ] Samples spatially representative of the deposit and of the mine plan
• [ ] Variability testwork present, not only composites
• [ ] Recovery used in the economic model supported by testwork, not extrapolated beyond it
• [ ] Deleterious elements assayed: arsenic, antimony, mercury, bismuth, fluorine, chlorine, magnesium
• [ ] Concentrate grade and penalty elements disclosed for base metals
• [ ] Grind size versus recovery relationship shown, and consistent with the modelled power cost
• [ ] Recovery reported by ore type or grade band, not a single blended figure for a variable orebody

Item 14 — Mineral resources

• [ ] Category split stated; share of Inferred noted
• [ ] Cut-off grade disclosed
• [ ] Metal price assumption behind the cut-off, compared to spot
• [ ] Capping or top-cutting of high assays described
• [ ] Block model parameters and search ellipse given
• [ ] Bulk density measured rather than assumed
• [ ] Statement of reasonable prospects for eventual economic extraction present
• [ ] Inclusive or exclusive of reserves — read the footnote before any arithmetic
• [ ] Grade-tonnage curve at multiple cut-offs, if provided

Item 15 — Mineral reserves

• [ ] Present at all — if absent, the project has no reserves regardless of its NPV
• [ ] Modifying Factors described
• [ ] Dilution and mining recovery assumptions stated and plausible (5% planned dilution on a narrow vein is optimistic)
• [ ] Pit shell or stope design parameters given
• [ ] Reserve price assumption stated, and compared with the resource price assumption

Items 16–21 — Mining, processing, infrastructure, costs

• [ ] Mining method stated, with alternatives considered
• [ ] Strip ratio: LOM and by period; pre-stripping quantified and in initial capex
• [ ] Pit slope angles supported by geotechnical drilling
• [ ] Underground: development metres before first production, and the assumed advance rate
• [ ] Ventilation capacity as a throughput ceiling
• [ ] Power, water and access costed, with source and tenure
• [ ] Tailings storage facility design, and closure cost
• [ ] Contingency stated — below 10% at feasibility, or below 15% at PEA, is thin
• [ ] Owner's costs present and non-nominal
• [ ] Working capital funded in the initial capital estimate
• [ ] Costs escalated to a stated base date

Item 22 — Economic analysis

• [ ] Pre-tax and post-tax NPV both shown; note which the headline quotes
• [ ] Discount rate stated and appropriate to commodity and jurisdiction
• [ ] Metal price deck versus spot and consensus
• [ ] Sensitivity tables on price, capex, opex and grade — not price alone
• [ ] NPV at spot −20% and capex +25% calculated by you, from the sensitivities
• [ ] Payback period and its basis
• [ ] Tax and royalty regime modelled, with rates
• [ ] Closure and reclamation cost in the cash flow
• [ ] Whether the NPV margin survives the study's own accuracy band

That last check is the one most worth doing. If a 25% capex overrun — well inside a PEA's stated accuracy band — eliminates the NPV, the study has not demonstrated viability. It has demonstrated fragility.

Items 23–25 — Context and conclusions

• [ ] Adjacent-property disclosure does not imply the subject property hosts similar mineralisation
• [ ] Risks and uncertainties enumerated in Item 25
• [ ] Recommendations and their budget — a modest recommended programme after a bullish study is a mismatch worth noting

Versus the previous study

• [ ] Resource and reserve tonnes, grade and contained metal, both vintages
• [ ] Cut-off grade and price assumption, both vintages
• [ ] Recovery, both vintages
• [ ] Strip ratio or dilution, both vintages
• [ ] Capex and opex, both vintages, on a common base date
• [ ] NPV and IRR, both vintages, on a common price and discount rate
• [ ] Does the company publish a reconciliation explaining each change?

A developer that publishes a clean PFS-to-FS comparison table is unusual and worth trusting more. NI 43-101 requires a news release on filing a technical report that reconciles any material differences in mineral resources or mineral reserves against prior disclosure — so at minimum, that release exists. Read it alongside the report.

Disclosure gaps that predict disappointment

• Cut-off grade absent from a resource statement
• Recovery from composites only, at feasibility stage
• No sensitivity table, or price-only sensitivities
• Contingency under 10% at feasibility
• Strip ratio falling from PEA to FS without explanation
• QP experience not matched to deposit type
• Historical data unverified and material to the estimate
• Permitting schedule assuming no delay in a jurisdiction with a track record of them
• No comparison against the superseded study

How Mining Terminal handles technical reports

Mining Terminal ingests technical reports from SEDAR+, ASX, EDGAR, LSE and other exchange feeds and extracts the structured content — resource and reserve tables by category, cut-off grades, recovery assumptions, capital and operating costs, NPV and IRR by discount rate and price case, mine life, strip ratio, mining method and QP attribution — with each value traced to the document and page it came from.

Successive studies for the same project are retained rather than overwritten, which is what makes the vintage-versus-vintage comparison above possible without opening two PDFs side by side. Where a filing omits a parameter, or its scale or currency is ambiguous, the field stays empty. An empty cell is honest; an inferred one is indistinguishable from a fact.

To run this comparison across a project or peer set, get in touch or ask Nara.

Related reading

• How to Read an NI 43-101 Technical Report
• JORC Resource Estimates Explained
• S-K 1300 Explained
• PEA vs PFS vs Feasibility Study
• Metallurgical Recovery Explained

Sources

• National Instrument 43-101 and Form 43-101F1 — Ontario Securities Commission
• NI 43-101 unofficial consolidation, effective 9 June 2023 — OSC PDF
• CIM Definition Standards, 10 May 2014 — BCSC-hosted copy
• The JORC Code, 2012 Edition, including Table 1 — jorc.org
• Regulation S-K subpart 1300 compliance guide — U.S. SEC

This article is educational and is not investment advice. Mining Terminal is a data platform, not a broker, dealer or investment adviser.