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PEC EPE Mining study materials
PEC EPE Mining study resources

PEC EPE Mining: Mining Engineering Practice

PEC EPE Mining · Work through your exam, one topic at a time.

All guide sections

Mining Engineering Practice

This section covers Mining Engineering Practice, the domain in which the PEC Engineering Practice Examination tests whether a candidate can turn theory into safe, economic, code-compliant mine decisions - method selection, blast and ground-control design, ventilation, statutory safety, and the economics behind a mining plan.

Core rules and concepts

  • Method selection follows geometry and rock mass first, economics second: shallow tabular orebodies suit open-pit or strip mining; strong, steeply dipping orebodies suit stoping; weak ground pushes you to caving or cut-and-fill with support.
  • Stripping ratio, SR = waste/ore, is tested against the break-even ratio (ore value − mining and processing cost per tonne of ore) ÷ waste mining cost per tonne of waste. Below break-even, stripping adds value; above it, it destroys value.
  • Blast design balances powder factor, fragmentation and vibration. Burden follows hole diameter and rock density; spacing is roughly 1.1–1.4 × burden; subdrill and stemming control toe and flyrock.
  • Ventilation must meet the statutory minimum quantity and velocity and must dilute methane and dust; coal mines need a second escape route and continuous methane monitoring.
  • Statutory compliance comes from provincial mining legislation and the rules framed under it (the Mines Act 1923 still applies in some jurisdictions).

Worked example

A bench blast uses 150 mm holes at a 3.5 m burden × 4.0 m spacing in a 12 m bench, loaded with 150 kg of ANFO per hole; in-situ rock density is 2.6 t/m³.

  1. Volume per hole = 3.5 × 4.0 × 12 = 168 m³.
  2. Tonnage per hole = 168 × 2.6 = 436.8 t.
  3. Powder factor = 150 ÷ 436.8 = 0.34 kg/t, equivalent to 150 ÷ 168 = 0.89 kg/m³.
  4. Sanity check: ANFO at 0.8 g/cm³ in a 0.15 m hole loads about 14.1 kg/m, so 150 kg fills roughly 10.6 m of a 13 m hole (12 m bench + 1 m subdrill), leaving about 2.4 m for stemming - workable.

Traps that cost marks

Mixing kg/t with kg/m³ without stating the basis; using loose density instead of in-situ density for tonnage; quoting ore tonnage without dilution and recovery; offering a rule-of-thumb air quantity where a regulation sets the minimum; and treating a memorised break-even stripping ratio as fixed when it moves with commodity price.