S. R. Torabi; M. Ataei; M. Javanshir
Abstract
A literature review revealed that most of the empirical equations introduced for determination of the uniaxial
compressive strength (UCS) of rocks based on the Schmidt hammer rebound number (N) are not sufficiently
reliable mostly due to the relatively low coefficient of correlations. This is ...
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A literature review revealed that most of the empirical equations introduced for determination of the uniaxial
compressive strength (UCS) of rocks based on the Schmidt hammer rebound number (N) are not sufficiently
reliable mostly due to the relatively low coefficient of correlations. This is attributed to the fact that in most
cases one formula is used for all types of rocks, although the density of rocks is introduced to the formulae in
some cases. On the other hand, if one specific relationship between N and UCS is introduced for one rock
type, the equation will yield a much higher coefficient of correlation. During a research program supported
by the Shahrood University of Technology, Iran, a third type of approach was considered. The study aimed
to establish a relationship between N and UCS of a rock mass under particular geological circumstances. As
an example, in this study, the immediate roof rock of coal seams in North-Eastern coal fields of Iran was
selected. In order to determine the N and UCS, a significant number of samples were selected and tested,
both in-situ and in the laboratory, and a new equation was established. The equation can be used to predict
UCS of the roof rock in coal extracting areas in this zone by performing simple in-situ Schmidt hammer
tests. It is predicted that such a procedure will be feasible for other geological conditions.
A. R. Arab-Amiri; A. Moradzadeh; N. Fathianpour; B. Siemon
Abstract
Helicopter-borne frequency-domain electromagnetic (HEM) surveys are used extensively for mineral and groundwater
exploration and a number of environmental investigations. To have a meaningful interpretation of the measured multi-
frequency HEM data, in addition to the resistivity maps which are ...
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Helicopter-borne frequency-domain electromagnetic (HEM) surveys are used extensively for mineral and groundwater
exploration and a number of environmental investigations. To have a meaningful interpretation of the measured multi-
frequency HEM data, in addition to the resistivity maps which are provided in each frequency or for some particular
depth levels, it is a necessity to have a suitable modeling technique to produce resistivity cross-section along some
specific profiles. This paper aims to: (1) develop a new inversion method to handle HEM data; (2) compare its results
with the well known Amplitude, Niblett-Bostick (NB), and Siemon inversion methods. The basic formulation of this
new inversion routine was provided based on the Zonge spatial filtering procedure to cure static shift effect on the
magnetotelluric (MT) apparent resistivity curves. When the relevant formulas and the required algorithm for the inverse
modeling of HEM data were provided, they were then coded in Matlab software environment. This new inversion
program, named as SUTHEM, was used to invert some sets of one and two dimensional (1D and 2D) model synthetic
data which were contaminated by random noise. It was also applied to invert one set of real field data acquired in the
NW part of Iran by the DIGHEM system. The obtained results of this method and their comparison with those of the
aforementioned methods indicate that SUTHEM is able to produce the results like those produced by the commercial
Siemon routine. In addition, the new inversion method is superior to the Amplitude and the NB methods particularly in
inversion of the noisy data.
V. F. Navarro-Torres; R. N. Singh
Abstract
Water has an important role in creating pollution problems in the mining regimes influencing the surrounding surface
environment. The purpose of this study is to make an assessment of groundwater quality in an underground mine site in
Portugal with a view of determining the pollution potential ...
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Water has an important role in creating pollution problems in the mining regimes influencing the surrounding surface
environment. The purpose of this study is to make an assessment of groundwater quality in an underground mine site in
Portugal with a view of determining the pollution potential of groundwater. In the corresponding surface area of this
underground mine, intersections of four faults form rock blocks which delimit the surface subsidence influencing the
flow pattern of the surface streams and the groundwater table resulting in inflow of groundwater and rainwater into
mining excavations. When this water comes into contact with the virgin rock mass containing pyrites in presence of
atmospheric air, acid mine water is formed. This acidic water reacts with the broken rock material dissolving metallic
sulphides into solution and also carrying suspended solids. When discharged in the “Boldehão” River, these waters
produce diverse environmental impact levels such as pH low and Zn high levels risk cause for irrigation, pH, Cu, Fe and
Mn high level risk for consumption human, and pH, Cu and Zn cause high level for fishes.
R. Ghavami-Riabi; H.F.J. Theart
Abstract
The massive sulphide deposit at Kantienpan Cu-Zn mine is hosted by volcano sedimentary succession known as the
Areachap Group, in the eastern part of Namaqua Metamorphic Province, South Africa. The deposits were affected by a
complex deformation and metamorphic history and represent ...
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The massive sulphide deposit at Kantienpan Cu-Zn mine is hosted by volcano sedimentary succession known as the
Areachap Group, in the eastern part of Namaqua Metamorphic Province, South Africa. The deposits were affected by a
complex deformation and metamorphic history and represent examples of upper amphibolite to granulite grade
metamorphosed volcanic-hosted massive sulphide (VHMS) deposits. The principal purpose of this research is to
characterise the primary geochemical halo’s related to VHMS deposits in this mine. Lithogeochemical characterization
of the primary haloes is based on borehole samples of the footwall, ore zone and hanging wall successions.
Geochemically, the ore zone and alteration zones at Kantienpan VHMS ore deposit display a high peraluminous ratio
confirming the peraluminous nature of these zones as indicated mineralogically and lithologically. The intervals
identified in sampled borehole core with low CaO and Na2O and with high MgO and K2O contents represent the
alteration zone in the original footwall rocks of the deposit.
A. H. Ansari; K. Alamdar
Abstract
Potential field methods such as gravity and magnetic methods are among the most applied geophysical methods in
mineral exploration. A high-resolution technique is developed to image geologic boundaries such as contacts and faults.
Potential field derivatives are the basis of many ...
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Potential field methods such as gravity and magnetic methods are among the most applied geophysical methods in
mineral exploration. A high-resolution technique is developed to image geologic boundaries such as contacts and faults.
Potential field derivatives are the basis of many interpretation techniques. In boundary detection, the analytic signal
quantity is defined by combining the values of horizontal and vertical derivatives. The outlines of the geologic
boundaries can be determined by tracing the maximum amplitudes of analytic signal. However, due to superposition
effects, in some cases that a variety of sources are adjacent, the detected boundaries are blurred. To overcome this
problem, this study used enhanced analytic signal composed of the nth- order vertical derivative of analytic signal. The
locations of its maximum amplitudes are independent of magnetization direction and geomagnetic parameters. This
technique is particularly suitable when interference effects are considerable and when remanent magnetization is not
negligible. In this paper this technique has been applied to gravity data of southwest England. Using this method, five
granites outcrops and their separating faults are enhanced accurately.
J. Gholamnejad; A.R. Mojahedfar
Abstract
The determination of the Ultimate Pit Limit (UPL) is the first step in the open pit mine planning process. In this stage
that parts of the mineral deposit that are economic to mine are determined. There are several mathematical, heuristic
and meta-heuristic algorithms to determine UPL. The optimization ...
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The determination of the Ultimate Pit Limit (UPL) is the first step in the open pit mine planning process. In this stage
that parts of the mineral deposit that are economic to mine are determined. There are several mathematical, heuristic
and meta-heuristic algorithms to determine UPL. The optimization criterion in these algorithms is maximization of the
total profit whilst satisfying the operational requirement of safe wall slopes. In this paper the concept of largest pit with
non- negative value is suggested. A mathematical model based on integer programming is then developed to deal with
this objective. This model was applied on an iron ore deposit. Results showed that obtained pit with this objective is
larger than that of obtained by using net profit maximization and contains more ore, whilst the total net profit of
ultimate pit is not negative. This strategy can also increase the life of mine which is in accordance to the sustainable
development principals.
