You are the mine manager of a local fluorspar mine. You are currently operating 4 different
orebodies on your mine site as surface mining operations. Orebody A is the only high-grade
orebody and thus the ore coming from this orebody is required as a "sweetener" in order to
guarantee a continuous feed to the processing plant.
The surface mining operation on orebody A had to be stopped due to an extremely
unfavourable ore-to-waste-ratio. Now the company CEO asks you to investigate the
possibility to transform the surface mine on orebody A into an underground operation. Please
answer the following 10 Questions. More information is given at the attached papers, you can
use this papers to visualize your answer with sketches.
Given information about the deposit:
• Total ROM from all four orebodies is 120.000 t/a.
• Orebody A has to contribute 40.000 t/a from the future underground operation.
• For the future underground mine you have access to all existing mining services from
the ongoing surface mines (e.g. workshops, labs, electricians, mechanics, grade
controller, mine surveyor ...)
• Until now: extraction in surface mining.
• Surrounding rock Fenite (uniaxial strength 200 - 250 MPa}, host rock highly alterated
in a 2 m wide contact zone to the orebody
• Hydrothermal vein deposit, orebody A splits into three parallel ore veins (uniaxial
strength 20 - 50 M Pa)
• Thickness 1 - 20 m, dip 40 - 60 gon, CaF2-content 55 %
• Underground mine will be operated as one-shift operation with lOh/shift
• 250 Working days/ year
Question 1 [10 marks]
Describe your development plan for the underground mine, indicate the placement and
lineage of the surface openings in the attached drawings
Question 2 [10 marks]
Select an appropriate mining method und substantiate your decision
Question 3 [10 marks]
Name type and number of additionally required mobile mining equipment for the
underground operation Please give a payload range for your haulage machines
Question 4 [10 marks]
Compare diesel and battery driven mobile equipment. Substantiate your choice for the new
mine
Question 5 [10marks]
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