TN175 : Blastability classification of rock masses of Gol-e-Gohar iron ore mine and proposing proper drilling and blasting pattern
Thesis > Central Library of Shahrood University > Mining, Petroleum & Geophysics Engineering > MSc > 2011
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Abstarct: One of the most important activities associated with mining excavation is drilling and blasting operations. In this regard, proper grinding and reducing the side effects of the explosion are of the great importance. Lack of detailed information on the design, drill-ing and blasting pattern can result in poor achievement in predefined purposes. In de-signing an optimum blast pattern, both of the controllable and uncontrollable factors (e.g. rockmass properties) should be taken into consideration simultaneously. Local geo-logical conditions, rock mass quality (e.g. strength, joints conditions), pattern geometry, loading and transportation of equipment, type of delivery system and explosion are of the most significant issues considered by the designers. Often, designing patterns are baxsed on the empirical methods. These methods are usually used with many simplifica-tion and assumptions resulted in reducing the efficiency of the system under study. In addition, there are other methods which are mainly baxsed on the rock mass properties. Intact rock and rock mass properties, especially joints conditions, are the basic features are considered when one uses these methods.
In this study, a comprehensive study has been done on the relevant contexts and the most effective parameters in designing the blasting pattern, mainly those methods relay on the mass rock properties, are reviewed. Afterward, after study on the various blasting results done on the Gol Gohar iron ore mine, existed problems were recognized and some recommendation have been offered to improve the current condition of the blast-ing operations. To collect the required data, a field study has been taken into account and rock mass engineering specifications required to determine the blastability index (BI) and rock fragmentation index (RFI) in more than sixty point of Gol Gohar Iron Ore Mine were studied. Rock samples were collected and transported to the laboratory from each of the sampling points. A uniaxial compressive strength, density and hardness tests have been carried out on the samples collected. The mechanical properties of intact rock, geo-mechanical characteristics of rock mass, blastability index and rock fragmentation index were determined for the rock masses located on those sixty points mentioned. Then, utilizing the parameters obtained, specification of blasting geometry was designed and specific charge was determined. At the end, the results of rock mass baxsed methods were compared with those designed by the mine workers and it was concluded that those points where characteristics of the implemented methods are close to the patterns of rock fragmentation index (RFI) are associated with a better results.
Keywords:
#Evaluation of the blasting #blastability index #rock fragmentation index Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
Visitor: