PE Mining case studies
PE Mining · Put your knowledge to work in context.
The Principles and Practice of Engineering (PE) exam in Mining and Mineral Processing is one of the more than 20 PE discipline exams offered by NCEES. It is a computer-based licensure exam that tests for a minimum level of competency in the discipline; NCEES describes the PE exam generally as designed for engineers who have gained a minimum of four years of post-college work experience in their chosen engineering field. The PE Mining case studies are 6 cases and about 4,390 words.
1Marginal Cut-off Grade With a Half-Empty Mill
You are the planning engineer at an underground gold mine. The 1.20 Mt/y mill is fed by a 0.90 Mt/y sublevel stoping operation, so 300 kt/y of mill capacity sits idle.
640 words, about 3 min2Load-Out Bay Widening in Weak, Jointed Ground
During widening of a 5.0 m x 5.5 m decline into a 9 m wide load-out bay, a 1.5 m thick slab of crown rock fell between existing bolts in altered andesite (UCS about 25 MPa). Two joint sets control the failure: one smooth, clay-coated set striking across the drive at 45 degrees, and a second set at 70 degrees with 0.3-0.6 m spacing.
564 words, about 3 min3Vibration Limit, Fragmentation and a Village at 100 m
A 100 mm hole open-pit blast (8 m bench, 3.5 m burden, 3.0 m spacing, 42 kg emulsion per hole, 25 ms pyrotechnic delays) is 100 m from a village. Your seismograph at the nearest house records 14 mm/s peak particle velocity, and the site-specific regression from 20 monitored events is PPV = 700 x SD^(-1.5), where SD = distance (m) / square root of charge weight per delay (kg).
803 words, about 4 min4Diesel Load Outruns the Auxiliary Ventilation
A single-heading decline at 350 m is ventilated by a 1.2 m diameter forcing column delivering 22 m3/s at the face; the fan is rated 30 m3/s at the collar. Working at the face: one 200 kW development jumbo and two 250 kW diesel loaders, all running during mucking.
769 words, about 4 min5Grind Finer, Feed Less: A Concentrator Trade-Off
A 2.4% Cu porphyry concentrator treats 900 t/h at P80 = 150 micrometres with 88% rougher-scavenger copper recovery. Locked-cycle pilot work shows that grinding to P80 = 106 micrometres lifts recovery to 91.0%, but Bond work index testing and the installed power indicate throughput would fall to about 780 t/h at the same draw.
767 words, about 4 min6Pedestrian-Vehicle Interaction, an Improvement Notice and a Tonnage Bonus
At a 480,000 t/y underground gold mine (2.6 g/t, 92% recovery), three lost-time injuries in 14 months have all involved pedestrians and load-haul-dump units on the 240 m level. Management proposes a 1.8 M proximity-detection and tagging system.
847 words, about 4 min