PE Mining flashcards
PE Mining · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Cutoff grade
- Minimum ore grade at which revenue from recovered metal covers mining, processing, refining, and general costs; material below it is normally treated as waste.
- Stripping ratio
- Ratio of waste tonnes mined to ore tonnes mined; the break-even ratio compares waste mining cost with the net value of the ore.
- Room-and-pillar
- Underground method that leaves pillars of ore to support the roof; recovery depends on pillar size, panel layout, and ground conditions.
- Longwall mining
- High-extraction underground method using a moving coal or ore face supported by hydraulic shields; it produces controlled and predictable subsidence.
- Sublevel stoping
- Open-stoping method for steep, competent orebodies; ore is blasted from sublevels and drawn from below, requiring stable walls and back.
- RMR
- Rock Mass Rating sums UCS, RQD, joint spacing, joint condition, and groundwater scores; values range from 0 to 100, with higher values indicating better rock.
- Q-system
- Tunnelling quality index Q = (RQD/Jn)(Jr/Ja)(Jw/SRF); used to classify rock mass quality and estimate support requirements.
- GSI
- Geological Strength Index estimates rock mass strength from blockiness and joint surface conditions; it is used in Hoek-Brown failure criteria.
- Pillar factor of safety
- Ratio of pillar strength to pillar stress; stress is often estimated from the tributary area load divided by pillar area.
- Subsidence angle
- Angle from vertical that defines the surface influence zone above underground extraction; it depends on rock mass, depth, and extraction geometry.
- Rock bolting
- Rock reinforcement using tensioned or grouted bolts; bolt length and spacing are selected from span and rock mass classification.
- Powder factor
- Explosive mass divided by blasted rock volume or tonnes; it controls fragmentation, flyrock, and blasting cost.
- Burden
- Distance from a blast hole to the nearest free face; excessive burden causes poor fragmentation, toe, and high vibration.
- Stemming
- Inert material placed in the collar of a blast hole to confine explosive gases and reduce flyrock and airblast.
- Presplit blasting
- Closely spaced, lightly charged holes fired before the main blast to create a fracture plane that protects the final wall.
- Velocity of detonation
- Speed at which the detonation wave travels through an explosive, typically 2,000–6,000 m/s; it affects energy release and fragmentation.
- Misfire
- Charge that fails to detonate as planned; the area is marked, fumes cleared, and the charge removed under controlled procedures.
- Atkinson equation
- Ventilation pressure loss relationship ΔP = R Q²; resistance R depends on friction factor, airway length, perimeter, and area cubed.
- Fan laws
- For a fixed fan and system, airflow varies with speed, pressure with speed squared, and shaft power with speed cubed.
- Methane explosive range
- Methane-air mixtures are explosive at roughly 5% to 15% methane by volume; ignition sources and accumulation must be controlled.
- Parallel airways
- For parallel airways, equivalent resistance satisfies 1/√R_eq = Σ(1/√R_i); splitting airflow lowers total resistance.
- Acid mine drainage
- Acidic, metal-rich drainage formed when sulfide minerals oxidize; managed by preventing water contact, neutralizing, and collecting contaminated water.
- Bond work index
- Empirical ore-specific energy parameter for crushing and grinding; a higher work index means more energy is needed to reduce the ore.
- Bond equation
- Specific grinding energy W = 10 Wi (1/√P80 − 1/√F80) kWh/t, with P80 and F80 expressed in micrometres.
- Froth flotation
- Mineral separation using collectors that make valuable particles hydrophobic and frothers that stabilize bubbles; particles report to the froth.
- Conveyor capacity
- Mass capacity of a conveyor equals belt cross-sectional area times belt speed times bulk density.
- Truck cycle time
- Time for a truck to load, haul, dump, return, and queue; it determines truck productivity and fleet matching with loaders.
- NPV
- Net present value is the sum of discounted future cash flows minus initial capital; a positive NPV creates value at the discount rate.
- LTIFR
- Lost-time injury frequency rate = lost-time injuries × 1,000,000 divided by total hours worked over the reporting period.
- Hierarchy of controls
- Risk control order: eliminate, substitute, engineer, administrate, then PPE; higher-level controls are generally more reliable than PPE.
- AISC
- All-in sustaining cost includes cash costs, sustaining capital, royalties, and general administration; it is used to compare operating performance.
- Risk matrix
- Tool that ranks hazards by likelihood times consequence, producing a risk score used to prioritize controls and acceptance decisions.