JOURNAL OF MINERAL RESOURCES ENGINEERING
Year:2018 | Volume:2 | Issue:4 |Papers Count:6

Exploration of mineral resources by using remote sensing techniques is done in different ways. One way is to use alteration mapping. In this study، Spectral angle mapper and Support vector machine algorithms were used to separate alterations of porphyry copper deposit. ASTER is an advanced multispectral imager that covers a wide spectral region from the visible to the thermal infrared with high spatial، spectral and radiometric resolution. In this study Aster data and spectral angle mapper and support vector machine algorithms were used to classify the alteration zones. The support vector machine (SVM) is a supervised classification increasingly used in geological mapping. It aims to assign the pixels of the image to classes through an optimal hyperplane and separating them، so that the margin between the two classes becomes maximal. Band ratio and principal component methods used to highlight the alteration zones. Th results of the band ratio method were used as training data and the result of principal component analysis were used as testing data. The similarities of support vector machine and spectral angle mapper algorithm with principal component analysis results are equal to 81% and 89%، respectively.

The studied area could be found in Tarq 1: 100000 Geochemicalmap. Initial geochemical investigation is done by Iran Geological Survey and Mineral Exploration (IGS) using stream sediments analysis method. This district mainly is covered by Precambrian to Quaternary Rocks. The geochemistry of the gold mineralization seems to be very important with regard to the sign of gold mineralization. Based on this aim، it is important to find the relationship of geochemical behavior of Au، As and Sb within the reported geochemical halo to determine both promising areas and gold estimated grade. To achieve this goal، K-means which is a powerful method has been applied. K-means is a clustering method based on minimizing sum of Euclidean distances of each sample from their own group centers. Here، the clustering quality function (S(i)) and the desirability of the cluster are used to find the optimized number of clusters. Finally، by taking into account the cluster centers and the results concerned، equations were presented for the prediction of the amount of the gold element in terms of four parameters: arsenic، antimony، X and Y associated to the sampling points. Also shown are the correlation coefficient of its validation equal to 72. The superiority of the results of the behavioral measurement of the elements related to this method were compared to the correl.

Annual increasing depth in Angouran Lead & Zinc open pit mine، along with the technical، topographic and geomechanical limitation causes an increase in transportation costs and a reduction in efficiency. The existence of underground excavations in the high grade sulfurous zone promotes a research on the identification and analysis of applicable technical solutions for reducing the transportation costs in the open pit mining using existing underground excavation. For this purpose، at first، the existing underground excavation network was modeled using Micromine software. Then، the modelling of open pit ultimate pit limit was performed by Datamine & NPV scheduler softwares to determine the depth and the range of expansion of the cavity. By adapting this model with underground network، seven scenarios have been specified to to connect open pit limit and underground network. At the next step، superior scenarios were presented based on excavation tonnage، operating cost and construction duration criteria، in which scenario 6 was offered as the preferred scenario. In this scenario، the connection of pit limit and underground space was performed with 3 excavations. The first excavation is the inclined shaft connecting the upper tunnel to elevation 2840 for open pit waste material handling. At the next step، excavation of a drift from bench 2804 to middle of this shaft was performed. In order to get access to the lower elevations، an underground zigzag ramp ramified from the main ramp will connect to elevation 2768. The operation of this scenario brings aboutan improvement to the supplying of filling materials to the underground operating spaces.

Characterisation of the deformation behavior of the brittle rocks during loading plays a significant role on rock damage growth. There are a variety approaches to monitor the damage development. Among which the method of Acoustic Emission، due to its accountability، has attracted many researchers’ attention in recent years. The paper describes fracture mechanism of pseudo-rock samples by using Brazilian Test results. Hence، evolution of crack growth and its effect on tensile strength is the prime objective of this research. The work has been performed numerically by using UDEC (Universal Distinct Element Method) and RFPA (Rock Failure Process Analysis) for DEM and FEM analyzes، respectively. The effect of size and position of the artificial voids in disc-type samples on their tensile strength have been investigated. On this basis، several numerical models were constructed and analyzed. Typically، tensile cracks were initiated at the bottom or at the top of the voids، and then propagated parallel to the loading axis and finally reached to the sample surface. The results obtained by numerical methods have been compared with those obtained by Brazilian laboratory tests. Crack initiation، propagation، and coalescence produced by the numerical models have proven very good conformity with the experimental tests’ results. Finally، it has been concluded that by increasing the porosity، the corresponding tensile strength، count، and energy required to brick the rock will decrease exponentially. However، due to plane strain analysis of numerical software، tensile strength is estimated less than that obtained experimentally.

Seismic facies analysis is a powerful technique used in extracting stratigraphic information and reservoir properties from seismic data. This technique can be implemented as a useful tool in different stages of exploration، production and development of hydrocarbon fields. In this paper، travel time samples (seismic traces) related to seismic reflections is grouped in similar classes. Using multiple seismic attributes within the target interval help us to construct a conceptual multi-attribute space in which each attribute is considered to be related to a property، or response of rock (and/or fluid). In this study، two unsupervised and supervised techniques are implemented for seismic facies analysis. In unsupervised approach، which is based entirely on the internal structure of data، and does not use any type of well and geological data as an auxiliary input to the predicting network، a self-organizing neural network (NN) is used. The results of both classifications in the study area are highly convergent and also show good consistency with petrophysical well data. In addition to estimating the petrophysical properties in interwell spaces، the use of index wells for supervision on classifications verifies the unsupervised classification in reservoir interval. This brings about a high confidence for the application of unsupervised classification. Consequently، generation of unsupervised facies maps in different time horizons facilitates the interpretation of property changes related to each seismic facies. Reservoir properties changes related to each facies in a facies map with three classes highly correspond with the petrophysical properties concerned.

The present work aims to study the feasibility of sulfur removal from Soork iron ore down to lower than 0. 1% using the flotation process. According to the characterization analysis، the ore consists of 50. 37% iron and 4. 12% Sulfur. The ore sample was divided into different size classes using screen size analyzing method. Then، wet magnetic separation experiments were conducted for three size classes in order to determine the degree of liberation. The d80=106 µ m size class was found as an appropriate degree of liberation. Wet magnetic separation experiments were performed at 800G intensity for 3 min feeding and water flowrate of 4 liters per min، drum rotational speed of 54 RPM with rotation parallel to the direction of feeding in which an iron grade of 63% along with a Sulfur content of 0. 52% with an iron recovery of 96% was obtained. To do further Sulfur reduction، the concentrate of the magnetic separation was reprocessed using reverse flotation to remove pyrite. Then، to reach an optimum operational condition in terms of flotation time and reagent usage، a few tests were performed and finally the flotation time of 5 min along with a collector dosage of 100 g/Mg in pH=9 was found to be the best possible condition to reach a Sulfur content of lower than 0. 1%. Also، a yield recovery of 95. 96% for iron concentrate with an overall iron recovery of 94. 9% was obtained.