Journal of Applied Mathematics / 2014 / Article / Tab 1

Research Article

Evaluation of Underground Zinc Mine Investment Based on Fuzzy-Interval Grey System Theory and Geometric Brownian Motion

Table 1

Input parameters.

Mine ore production (t/year)100 000
Zinc grade (%) 4.2, 5.0 = 0.042, 0.050
Metal content of concentrate (%) 
47, 52 = 0.47, 0.52


39, 42 = 0.39, 0.42
Mill recovery (%) 75, 80 = 0.75, 0.80

Metal price ($/t)
20092010201120122013

January12032415237619892031
February11182159247320582129
March12232277234120361929
April13882368237120031856
May14921970216019281831
June15551747223418561839
July15831847239818481838
August18182047219918161896
September18792151207520101847
October20712374187119041885
November21972283193519121866
December23742287191120401975

Initial (capital) investment ($) 3000000, 4000000
Operating costs, geometric Brownian motion,
yearly time resolution ($/t), equation (39)
Number of simulations
Spot value 32; drift 0.020; 
cost volatility rate 0.10;  
Construction period (year)3 
Mine life (year)5 
Discount rate (%) 7, 10 = 0.07, 0.10