A new imaging condition based on poynting vectors in RTM seismic imaging method
فرزاد
مرادپوری
دانشکده مهندسی معدن، نفت و ژئوفیزیک، دانشگاه صنعتی شاهرود
author
Ali
Moradzadeh
استاد دانشکده مهندسی معدن، پردیس دانشکدههای فنی، دانشگاه تهران؛ استاد همکار دانشکده مهندسی معدن، نفت و ژئوفیزیک، دانشگاه صنعتی شاهرود
author
مهرداد
سلیمانی منفرد
استادیار دانشکده مهندسی معدن، نفت و ژئوفیزیک، دانشگاه صنعتی شاهرود
author
Reynam
Cruz Pestana
استاد دانشکده فیزیک، گروه ژئوفیزیک و زمینشناسی، دانشگاه فدرال باهیا، سالوادور، برزیل
author
text
article
2017
per
The low frequency noises are the characteristic of reverse time migration (RTM) method. In this study, a high pass filter, Laplacian filter and an imaging condition based on the down-going components of the wave-field are used to suppress the low frequency noises. Then, a new imaging condition as the heart of RTM is presented to suppress these low frequency noises. In the above imaging condition, the wave-fields are separated to their down-going and up-going components by the information of the poynting vectors. The poynting vectors information are also used to calculate the reflection angles as a basis for the proposed weighted function. The results of implementation for the improved RTM method on a synthetic dataset (Marmousi) indicates the efficiency of the proposed method to suppress the low frequency noises in producing high quality, high illuminated depth migrated image. The improved method has the capability to identify all the subsurface geological structures properly.
Journal of Mining Engineering
Iranian Society of Mining Engineering (IRSME)
1735-7616
11
v.
33
no.
2017
1
9
https://ijme.iranjournals.ir/article_24410_0982804ff218fea9dfbaa4e247cc53d8.pdf
Investigation of liner shape effects on load movement in SAG mills by discrete element method (DEM)
زهرا
بی باک
کارشناسی ارشد مهندسی فرآوری مواد معدنی، دانشگاه شهید باهنر کرمان
author
الهام
نعمت اللهی
کارشناسی ارشد مهندسی فرآوری مواد معدنی، دانشگاه شهید باهنر کرمان
author
علیرضا
قاسمی
دانشجوی دکتری مهندسی فرآوری مواد معدنی، دانشگاه شهید باهنر کرمان
author
مصطفی
مالکیمقدم
دانشکده فنی دانشگاه ولیعصر رفسنجان
author
صمد
بنیسی
دانشگاه شهید باهنر کرمان
author
text
article
2017
per
One of the reasons of importance of liners in grinding is its role in providing an appropriate trajectory for the charge (ore and grinding media) movement. Since it is not possible to study the charge movement by directly in industrial mills, physical (laboratory) or mathematical (software) simulation are used. Physical simulation is expensive and slow, so mathematical simulations have received much more attention. The simulation of the effect of liner shape on charge movement has provided a means to select the proper liner shape based on operating conditions and objectives. Furthermore, the liner shape changes during operation due to wear and impact which in turn influences the charge trajectory. The change in liner shape could be determined through liner profile measurement during operation or simulation. In this research, KMPCDEM software was used to simulate the charge movement by geometrical method of implementing the shell liners of the Sarcheshmeh and Gole-E-Ghohar SAG mills in the software. Point by point implementation of the measurements of liner profiles facilitated to study the trend of change in charge movement as liners wear. Comparison of the simulation and laboratory (i.e., 1 m diameter mill) results showed that the simulation of liners using the impact point as the criterion with an accuracy of 95.6% has been achieved.
Journal of Mining Engineering
Iranian Society of Mining Engineering (IRSME)
1735-7616
11
v.
33
no.
2017
11
19
https://ijme.iranjournals.ir/article_24413_69df288295b9f28a41e8b14f0fbe2918.pdf
The effect of physical and chemical properties of diluent on copper solvent extraction by CP150
zahra
heidari mofrad
دانشگاه بیرجند
author
سپیده
جوانشیر
هیئت علمی دانشگاه بیرجند
author
text
article
2017
per
Effective parameters on diluent quality in copper solvent extraction circuit have been investigated. Several experiments were carried out with 10% CP150 as extractant in 90% diluent with different aromatic contents (5-35%). Performance parameters such as kinetics, selectivity, separation time and entrainment have showed that, by increasing the aromatic content in diluent, the copper extraction rate, separation time and losses of extractant by entrainment have been decreased; If aromatic content increased from 5 to 35 %, entrainment and separation time declined about 50 % while aromatic content appears to help suppress iron co-extraction. Batch experiments repeated by several composition prepared from various ratios of Kerosene, Reasol 8401 and Reasol 8411. Results indicated that aromatic content of diluent must be controlled as well as physical properties especially where a mixture of several solvents are used as diluent. Low diluent viscosity improve the kinetics because of high phase dispersion; if diluent viscosity increase from 2.09 to 2.29 cSt, extraction rate in 30 seconds is reduced by 30%. Higher density and surface tension result in organic phase entrainment and solvent loss; so that, by increasing in surface tension from 26 to 27/3 mN/m, entrainment enhanced by almost 100%. However, high interfacial tension, density and viscosity enhanced Cu/Fe separation; if diluent density rise up 35 Kg/m3, Cu/Fe transmission factor is declined tenfold.
Journal of Mining Engineering
Iranian Society of Mining Engineering (IRSME)
1735-7616
11
v.
33
no.
2017
21
31
https://ijme.iranjournals.ir/article_24412_14beff459c708e279f6721a0ffb7cdd9.pdf
An investigation into the failure criteria parameters of Ramamurthy for massive up to jointed limestone without infill materials and smooth planes
Hassan
Moomivand
Assist. Professor of Urmia University
author
سیده هدی
معدنی
دانشگاه ارومیه
author
فرنوش
حاجی زاده
عضو ةیأت علمی دانشگاه ارومیه
author
میرعلی
محمدی
عضو هیأت علمی دانشگاه ارومیه
author
text
article
2017
per
Rock specimens having one, two and three cross - sets of single discontinuities and three cross - sets of discontinuities with one set having four parallel discontinuities, in different groups of various orientations (angle between planes of discontinuities and horizontal direction) of 0, 30, 45, 60 and 90 degrees have been prepared. The axial strength of various groups of jointed rock specimens have been tested under different confining pressure of 0, 5, 7, 10, 14 and 20 MPa. Parameters of Ramamurthy's failure criterion including: ratio of uniaxial compressive strength of jointed rock specimens to the uniaxial compressive strength of intact rock specimens (scj/sci), power of aj and triaxial strength factor (Bj) of this research have considerably different from their obtained values using present relationships particularly for higher values of frequency and number of sets of discontinuities, and presence of a dominant joint with orientation angle of 60 degree in the combination of discontinuities. The value of s and triaxial strength factor (mb) in Heok et al. rock mass failure criterion decreases with an increase of number of set and frequency of discontinuities and its minimum value occurs when there is a dominant joint having orientation angle of 60 degree. A new relationship between triaxial strength factor (mb), s and a with scj/sci ratio have been obtained for limestone as ratio of scj/sci can be determined by joint factor (Jf).
Journal of Mining Engineering
Iranian Society of Mining Engineering (IRSME)
1735-7616
11
v.
33
no.
2017
33
48
https://ijme.iranjournals.ir/article_24411_211e8b617f3fe2ae20b0b3b7094b7314.pdf
Fracture mechanics analysis of rock cracked discs using the boundary element method
Mahmoud
Behnia
Isfahan University of Technology, Mining Engineering Department
author
Seyed Hossein
Mirzeinali Yazdi
Malek Ashtar University of Technology, passive Defense Department
author
text
article
2017
per
Fracturing of rock structures occurs usually under mixed mode I-II loading. The determination of the complete fracture toughness envelopes (KI-KII) for rocks is essential since it may serve as a fracture criterion for crack initiation under mixed mode I-II loadings. A number of methods have been developed to determine the fracture toughness of these modes using different specimen configuration. The Brazilian disk specimens with a central crack is proposed by many researchers for investigating modes I, II, and mixed fracture toughness in brittle materials. In this study, the numerical program (2DFPM) was developed based on the boundary element method (displacement discontinuity method) for studying the fracture propagation on Central Straight through Crack Brazilian Disk (CSCBD) specimens. In-order to enhance the capability and accuracy of the numerical program, special elements (crack tip, and quadratic element) were used. The validity of the program was verified by different analytical and numerical results. The results from numerical analysis show that the inclination angle of the crack with respect to the diametrical load and the crack length have the most important impact on the SIFs (Stress Intensity factor) and fracture propagation path.
Journal of Mining Engineering
Iranian Society of Mining Engineering (IRSME)
1735-7616
11
v.
33
no.
2017
49
63
https://ijme.iranjournals.ir/article_24448_c57512db3c5a0c56a25b5f2cb578a40a.pdf
Optimization the ventilation cross-cut dimensions in old railway tunnels based on ventilation and stability aspects, case study: Gadook railway tunnel
سیده گلاله
حسینی
دانشگاه صنعتی امیرکبیر
author
Hasan
madani
استادیار دانشگاه صنعتی امیرکبیر
author
Korosh
shahriar
استاددانشگاه صنعتی امیرکبیر
author
ali
mortazavi
دانشیار دانشگاه صنعتی امیرکبیر
author
text
article
2017
per
Gadook tunnel with a length of 2887m is located in the railway track of Firoozkooh to Ghaemshahr, north of Iran. The length of this section was considered 12m in order to get initial stress around the main tunnel. The optimization of the cross-cut section was investigated for diameters 2.5, 3, 3.5 and 4m considering a good type of rock material, the pressure drop for each one was calculated and then 3m diameter cross-cut was chosen based on the calculated pressure drop. In order to analyze the stability, first, the geometry of the main tunnel and the cross-cut with the length of 12m and a diameter of 3m in Rhino software was constructed, then, the stability analysis was performed using FLAC3D software. The intersection of the main tunnel and cross-cut was designed trumpet like to prevent the additional pressure drop. The numerical calculations obtained by FLAC3D software revealed the displacement in the intersection and inside cross-cut is as small as 2 mm, so the cross-cut can be considered as self-stable. Since the cross-cut is designed for ventilation needs, in order to avoid pressure drop inside the cross-cut, the walls should be flattened. For this reason, a support system was proposed consist of 15cm lining for the cross-cut and 20 cm lining for the 25m inside the main tunnel around the intersection. To verify the support system is only for the need of ventilation and pressure drop in the cross-cut, the shotcrete support system with a 5cm thickness inside the cross-cut was investigated and minimal displacements were obtained again. Regarding a good rock material and stability inside the cross-cut, the step progress of 2m determined in order to excavate the cross-cut in six stages.
Journal of Mining Engineering
Iranian Society of Mining Engineering (IRSME)
1735-7616
11
v.
33
no.
2017
65
79
https://ijme.iranjournals.ir/article_24446_897124ef83eb7a7c3170850d5763a3a1.pdf
Environmental Impact Assessment in Open pit Mines, Case Study: The Sangan Iron Ore Mine in Khaf
محمد
عطائی
دانشگاه صنعتی شاهرود
author
الیاس
ایلخانی
دانشگاه شاهرود
author
رضا
خالوکاکایی
دانشگاه شاهرود
author
text
article
2017
per
Sustainable development results in balance between development and environment and consists of three main aspects including environmental, social and economic factors. All these parameters are related to each other and imbalance in any of them causes imbalances in other sectors. Mining activities are one of the most important industries for economic growth and social welfare in many countries. On the other hand, due to the many environmental effects of mining such as water and air pollution, soil erosion, various social and economic problems have led to enter the sustainable development into mining sector. Paying attention to sustainable development in the mining activities can reduce environmental problems and have positive social and economic effects. In modern mining, special attention is paid to the sustainable development. Nowadays exploitation and processing minerals are carried out with regard to sustainable development. This led to have more welfare and wealth for industrialized countries. Therefore, with special attention to the sustainable development in the mining industries one can enjoy a healthy environment and dynamic economy with social welfare. This research demonstrates the assessment of sustainable development of Sangan iron ore mine in Khaf with the use of environmental effects of this mine. The result showed that the mine has a poor stability level and is necessary to predict and carry out required activities based on the extent of the damage of various components.
Journal of Mining Engineering
Iranian Society of Mining Engineering (IRSME)
1735-7616
11
v.
33
no.
2017
81
93
https://ijme.iranjournals.ir/article_24445_355a86e80ea1325f5480f48b9ee93194.pdf
Prediction of over break phenomenon in tunnel excavation using intelligent optimization methods, Case study: Tazare coalmine
adel
motahedi
دانشجوی کارشناسی ارشد استخراج معدن، دانشکده معدن، نفت و ژئوفیزیک، دانشگاه شاهرود؛
author
فرهنگ
سرشکی
استاد دانشگاه صنعتی شاهرود
author
mohamad
ataei
استاد دانشکده معدن، نفت و ژئوفیزیک، دانشگاه شاهرود؛
author
text
article
2017
per
Knowadays tunnel excavation is an evident need according to the human requirement such as mineral supplement, transportation, underground storage etc. Over break is one of the unfortunate phenomenon’s that could be encountered in tunneling, particularly in the drill and blast tunneling method. Over break phenomenon, reduce the safety of the working environment and increase the operational costs. Over break prediction is the first step to decrease the damaging effects of this phenomenon in the tunnel construction process. The causing factors of over break are classified into two groups of uncontrollable factors (geological parameters) and controllable factors (blasting parameters) and all of the factors are nonlinearly correlated. In this study, 52 sets of causing factors and over break data were applied to the multiple linear and nonlinear regression, Artificial Neural Network (ANN), Fuzzy logic and Adaptive Network-based Fuzzy Inference System (ANFIS) to predict over break as output parameter. The determination coefficient (R2) values of multiple linear and nonlinear regression, Artificial Neural Network, Fuzzy and Adaptive Network-based Fuzzy Inference System Models have been calculated as 0.71, 0.73, 0.80, 0.95 and 0.91, respectively. The results of the prediction models illustrate that the fuzzy and ANFIS models, have done more appropriate prediction than other prediction models. Also, sensitivity analysis showed that burden value is the most effective parameter on the over break. With awareness of the over break occurrence, we can use controlling and preventing methods to reduce the harmful effects of this phenomenon, and ultimately improve project performance.
Journal of Mining Engineering
Iranian Society of Mining Engineering (IRSME)
1735-7616
11
v.
33
no.
2017
95
111
https://ijme.iranjournals.ir/article_24447_142c698e47687cb0562a919e6c777dc0.pdf