Introduction To Mining Engineering - Study Mode
[#226] Hydraulic ring main system is used to
Correct Answer
(A) get uniform pressure in powered support
[#227] Maximum supports are required within 10 m of freshly-exposed roof-why?
Correct Answer
(B) that portion generally remain unsupported due to violence of blasting & incumbent strata pressure is shifted towards pillar edge
[#228] Which of the following method was practiced in NECL for extraction of steep thick seam?
Correct Answer
(C) bhaska and tipong
[#229] A seam is worked at the depth of 120 m from surface and has a width galleries of 3.4 m. The percentage of extraction during development should be restricted to
Correct Answer
(C) 31.8%
[#230] In an underground mine output from the panel is 360 tpd, having 26 days of working in a month where incubation period of coal is 9 month. If recovery from the panel is 80% and pillar size is 30 m × 30 m, height 3 m, coal sp. gravity 1.8 then find out number of pillars in the panel.
Correct Answer
(B) 22