Rudarski radovi br 4 2011 - Institut za rudarstvo i metalurgiju Bor

access the deposit optimization in the<br />
Whittle software package.<br />
Many variations of the open pit, in a<br />
contour of limit copper content 0.15%,<br />
specifically 86 variants, were analyzed to<br />
select the best contour of balance reserves.<br />
Then, the open pit was designed in the<br />
software Gemcom, and based on it, a calculation<br />
of balance reserves was made, for<br />
which Gemcom was also used, and it is its<br />
module Volumetrics.<br />
2. THE APPLIED METHODS OF<br />
RESERVE CALCULATIONS<br />
Mini-block method was used for calculation<br />
the ore reserves in the deposit<br />
South Mining District Majdanpek.<br />
Mini-block method is professionally<br />
verified present in a detail in the relevant<br />
technical literature, where it is isolated as a<br />
separate method in a group of topological<br />
methods for calculation the ore reserves.<br />
In selecting the mini-block method, as<br />
the base, it was in a mind that the copper<br />
deposit South Mining District Majdanpek<br />
was basically explored by rectangular grid<br />
of exploration drill holes 100 × 50 m, and<br />
the contours of mineralization were tested<br />
in several horizons by mining prospecting<br />
works. Also, the deposit has a form of<br />
elongated lenses of uniform mineralization<br />
thickness.<br />
The adopted mini-blocks are a cube<br />
with sides of 15 m due to the designed<br />
height of exploitation benches, also 15 m,<br />
and ore thickness in it.<br />
Kriging method was used for evaluation<br />
the calculation blocks.<br />
In large deposits, as it is the case with<br />
the copper deposit South Mining District<br />
Majdanpek, the advantage of reserve calculation<br />
using computer technology in<br />
relation to the calculation of other (“manual”)<br />
methods are the following:<br />
� it is possible in a short period of<br />
time to generate a large number of<br />
variants, carry out their analysis<br />
and find the best solution,<br />
� thus obtained results have satisfactory<br />
accuracy and they are accepted<br />
as the representative in the expert<br />
public,<br />
� potential creditors and concessionaires<br />
require to comply with described<br />
methodology and that the<br />
deposit is displayed in a digital<br />
form.<br />
3. TECHNO-ECONOMIC DATA FOR<br />
EVALUATION THE<br />
DEPOSIT VALUE<br />
The adopted initial techno-economic<br />
data needed to evaluate the deposit value,<br />
are shown in Table 1. They were adopted<br />
on the basis of many years production<br />
experience in this mine, mine planning<br />
documents, existing studies for exploitation<br />
of this deposit and assess the trends in<br />
market prices of metals in the world in<br />
next period.<br />
Total investments for open pit and flotation<br />
are estimated to 50 000 000 $. Possible<br />
production capacity was adopted<br />
according to the Plan of development the<br />
copper ore production in RTB and it is 8.5<br />
million tons of ore annually.<br />
The condition of open pit, geodetic recorded<br />
on 05.02.2011, was taken for<br />
analysis the possibility of mining.<br />
The basic parameters of exploitation<br />
were adopted on the basis of gained experience<br />
in excavation the deposit, that is:<br />
- bench height, 15 m,<br />
- angle of bench slope, 70°,<br />
- angle of final pit slope in the range<br />
of 35 - 38°, and<br />
- width of bench level in the range of<br />
13.0 to 18.5 m.<br />
Review of other techno-economic parameters<br />
for deposit optimization is systematized<br />
in Table 1.<br />
No 4, 2011. 88<br />
MINING ENGINEERING