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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Iranian Journal of Earth Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Pollution,CPT,Moisture content,Coal Spontaneous Combustion
- چکیده:
- چکیده انگلیسی: There are several phenomenons for polluting the environment, especially in coalfields; which coal spontaneous combustion is one of them. The moisture content is one of the intrinsic characteristics of coal, which has an important role in the occurrence of this phenomenon. Therefore, this research predicts the coal spontaneous combustion tendency based on moisture content. The percentage of moisture content is a very important parameter on the occurrence of this process; so far a conclusion about the effect of moisture content on coal spontaneous combustion, a comprehensive study was done. 55 coal samples with different percentage of moisture content for the training of overall underground coalfields in Iran were collected and the CPT test method for each coal sample was carried out. Then, the method of regression analysis was used for modeling and predicting the coal spontaneous combustion tendency. The results show, the coal sample undergoes oxidation most rapidly when the moisture content supply is about under 20%, and it can reduce coal spontaneous combustion in excessed of 20%, because when moisture is present in excessed of 20%, the heat released by oxidation is used to evaporate the moisture. For validation and testing, 15 coal samples of another coalfield were collected and the CPT test method for each coal sample was carried out, and the results of the test method were compared by the regression equation. The results obtained from the models show that a good appropriate prediction has been done for determining the coal spontaneous combustion tendency by regression analysis.
- انتشار مقاله: 18-07-1397
- نویسندگان: Amir Saffari,Farhang Sereshki,Mohammad Ataei
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Mining and Geo-Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Macerals Content,R70 Test Method,Spontaneous Combustion of Coal
- چکیده:
- چکیده انگلیسی: Spontaneous coal combustion (SCC) is one of the significant hazardous phenomena in underground coal mines. The tendency of spontaneous coal combustion is an intrinsic property, due to the presence of the maceral content. Unlike its importance, this matter has not been discussed in detail among the researchers. Therefore, it is necessary to investigate the effect of this parameter on SCC. Maceral content is defined by the original vegetation from which coal is formed. The present study examines the role of maceral content on SCC, based on 51 coal samples with different maceral contents. These samples were collected from several Iranian underground coal fields, and the R70 test was carried out on each coal sample. By examining the results and comparing the R70 values, it was found that with an increase in the vitrinite and liptinite contents and a decrease in the inertinite content, the coal samples showed to have more tendency of spontaneous combustion.
- انتشار مقاله: 23-08-1397
- نویسندگان: Amir Saffari,Farhang Sereshki,Mohammad Ataei
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Mining and Geo-Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Empirical Models,effective parameter,open pit mines,rock fragmentation
- چکیده:
- چکیده انگلیسی: The assessment of fragmentation through blasting and therefore subsequent crushing and grinding stages is important in order to control and optimize the mining operation. Prediction of the mean size of fragmented rock by the rock mass characteristics, the blasting geometry, the technical parameters and the explosive properties is an important challenge for the blasting engineers. Some of the effective parameters on rock fragmentation have been investigated in several empirical models. A model for fragmentation in bench blasting was developed using the effective parameters on the existing empirical models, so as to propose a simple applicable model to predict X50. The proposed model was calibrated by nonlinear fits to 35 bench blasts in different sites from Sungun copper mine, Akdaglar quarry and Mrica quarry. In order to validate the proposed model, its results were compared to data obtained from six blast sites in Chadormalu iron ore mine and one in Porgera gold mine. The results indicated a small variance in X50 which is calculated by the proposed model, through the image processing approach. The Comparison of the powers between the proposed and the Kuz-Ram models showed that the specific explosive energy and the powder factor are almost the same. The advantage of the proposed model rather than the Kuz-Ram model is specific explosive energy, since this parameter includes the powder factor and the weight strength of explosive. Also a sensitivity analysis was carried out based on artificial neural network. The results showed that the burden and the specific explosive energy were the most effective parameters in the proposed model.
- انتشار مقاله: 14-07-1395
- نویسندگان: Hossein Inanloo Arabi Shad,Farhang Sereshki,Mohammad Ataei,Mohammad Karamoozian
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Mining and Geo-Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Wear Rate,ampere consumption,Cutting performance,Metaheuristic algorithm
- چکیده:
- چکیده انگلیسی: Artificial Intelligence (AI) techniques are used for solving the intractable engineering problems. In this study, it is aimed to study the application of artificial bee colony algorithm for predicting the performance of circular diamond saw in sawing of hard rocks. For this purpose, varieties of fourteen types of hard rocks were cut in laboratory using a cutting rig at 5 mm depth of cut, 40 cm/min feed rate and 3000 rpm peripheral speed. Four major mechanical and physical properties of studied rocks such as uniaxial compressive strength (UCS), Schimazek abrasivity factor (SF-a), Mohs hardness (Mh), and Young’s modulus (Ym) were determined in rock mechanic laboratory. Artificial bee colony (ABC) was used to classify the performance of circular diamond saw based on mentioned mechanical properties of rocks. Ampere consumption and wear rate of diamond saw were selected as criteria to evaluate the result of ABC algorithm. Ampere consumption was determined during cutting process and the average wear rate of diamond saw was calculated from width, length and height loss. The results of comparison between ABC’s results and cutting performance (ampere consumption and wear rate of diamond saw) indicated the ability of metaheuristic algorithm such as ABC to evaluate the cutting performance.
- انتشار مقاله: 18-02-1396
- نویسندگان: Masoud Akhyani,Farhang Sereshki,Reza Mikaeil,Mohammad Taji
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Mining and Geo-Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: MATLAB Software,Auto delineation,Fragmentation Measurement,GoldSize,SplitDesktop
- چکیده:
- چکیده انگلیسی: In this research, first of all, the existing problems in fragmentation measurement are reviewed for the sake of its fast and reliable evaluation. Then, the available methods used for evaluation of blast results are mentioned. The produced errors especially in recognizing the rock fragments in computer-aided methods, and also, the importance of determination of their sizes in the image analysis methods are described. After reviewing the previous work done, an algorithm is proposed for the automated determination of rock particles’ boundary in the Matlab software. This method can determinate automatically the particles boundary in the minimum time. The results of proposed method are compared with those of Split Desktop and GoldSize software in two automated and manual states. Comparing the curves extracted from different methods reveals that the proposed approach is accurately applicable in measuring the size distribution of laboratory samples, while the manual determination of boundaries in the conventional software is very time-consuming, and the results of automated netting of fragments are very different with the real value due to the error in separation of the objects.
- انتشار مقاله: 05-01-1395
- نویسندگان: Farhang Sereshki,Morteza Hoseini,Mohammad Ataei
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Mining and Geo-Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Numerical modelling,Sensitivity analysis,Underground Structures,frame analysis,segmental tunnel lining
- چکیده:
- چکیده انگلیسی: There are several methods for analysing the behaviour of underground structures under different loading conditions. Most of these methods have many simplifications; therefore, in some cases, the results are too conservative and a very high safety factor, usually of more than 2 is needed. On the other hand, for stability analysis and the designing of support systems, these methods consider segmental lining and its joints as a uniform lining or a lining with pin connections. In this study, numerical modelling of the segmental lining of a tunnel was analysed using a sensitivity analysis of the static modelling. The numerical results were obtained by using a finite difference method (FLAC2D). Using this form of analysis, a new simple methodology was introduced so that more reliable results can be obtained. By comparing the frame analysis results obtained by the SAP2000 software with those obtained by the proposed method, it was concluded that the suggested method can be used as a simple and reasonable approach for the segmental lining of underground structures such as tunnels.
- انتشار مقاله: 28-05-1393
- نویسندگان: Akbar Salemi,Fathang Sereshki,Morteza Esmaeili
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Mining and Geo-Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: classification,Coal,Coal spontaneous combustion potential index (CSCPi),Rock engineering systems (RES),Eastern Alborz coal mines
- چکیده:
- چکیده انگلیسی: Subject analysis of the potential of spontaneous combustion in coal layers with analytical and numerical methods has been always considered as a difficult task because of the complexity of the coal behavior and the number of factors influencing it. Empirical methods, due to accounting for certain and specific factors, have not accuracy and efficiency for all positions. The Rock Engineering Systems (RES) approach as a systematic method for analyzing and classifying is proposed in engineering projects. The present study is concerned with employing the RES approach to categorize coal spontaneous combustion in coal regions. Using this approach, the interaction of parameters affecting each other in an equal scale on the coal spontaneous combustion was evaluated. The Intrinsic, geological and mining characteristics of coal seams were studied in order to identifying important parameters. Then, the main stages of implementation of the RES method i.e. interaction matrix formation, coding matrix and forming a list category were performed. Later, an index of Coal Spontaneous Combustion Potential (CSCPi) was determined to format the mathematical equation. Then, the obtained data related to the intrinsic, geological and mining, and special index were calculated for each layer in the case study (Pashkalat coal region, Iran). So, the study offers a perfect and comprehensive classification of the layers. Finally, by using the event of spontaneous combustion occurred in Pashkalat coal region, an initial validation for this systematic approach in the study area was conducted, which suggested relatively good concordance in Pashkalat coal region.
- انتشار مقاله: 20-10-1391
- نویسندگان: Amir Saffari,Farhang Sereshki,Mohammad Ataei,Keramat Ghanbari
- مشاهده