Destruction of Rock Upon Blastingof Explosive Agent (original) (raw)
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An investigation into blasting design for mining excavations
Mining science & technology, 1988
Blastability of rock is defined utilizing Bieniawski's rock mass classification with Hoek and Brown m and s values. A new method is introduced to determine optimum blasthole diameter, burden, spacing, stemming length, ratio of maximum burden to the bench height and relationship between the blastability, rock strength factor and specific consumption of explosive. Moreover, sets of empirical equations are suggested to determine the amount of explosive per blasthole or chamber under various surface and underground mining conditions. This was done by the use of evaluated blasting coefficients for ranges of ground conditions.
Setting the drilling-blasting parameters depending on the geomechanics of rocks
2011
In order to improve the performance of mine workings development technologies is necessary to establish optimum process parameters for drilling-blasting operations, as a function of the geo-mechanical characteristics of rocks. The most important condition for successful drilling-blasting operations, with respect to the technical, economic and safety point of view, is a realistic projection of their choice, both in terms of explosive materials and concerning the operating parameters. The most important characteristics of rocks which give guidance on the excavation by drilling-blasting are: compressive strength and abrasiveness of rocks. The paper deals with the speed of drilling and explosive specific consumption for the two strength characteristics of rocks.
Optimization study of blasting operations in Roşia Poieni open pit mine, Romania
Mining of Mineral Deposits, 2021
Purpose. Drilling-blasting technology is one of the simplest and most often used techniques in open pit mining. This allows the excavation of a large volume of rock and useful mineral substance. The operation of blasting using the energy of explosives plays an important role in open pit exploitation, being also the key element of the blasting process through which a corresponding granulometry is obtained. This operation is a part of a series of interdependent operations, in the sense that each operation determines a certain result that will be an important element for the next operation that takes place in the working face. Consequently, the blasting operation with explosives should not be considered as an independent act. A global approach to the entire production technological process including blasting is required. Methods. In the optimization study, the basic method consisted in the analysis of the blasting operations performed at the drilling diameter of 250 mm (blasting techno...
A brief history of the development of blasting and the modern theory of rock breaking
Journal of Degraded and Mining Lands Management, 2016
The article is devoted to the task today to improve the effectiveness of blasting during construction of horizontal and inclined mine excavations. Construction of new and reconstruction of existing mines requires large volume of excavation works, which length can reach tens of kilometers for only one project. Drilling and blasting workings allow not only to break out rocks from a frontal part of an excavation, but also cause an internal effect, which can lead to undesired damage that, in turn, often lead to increased expenses for excavation operations and safety problems for personnel. Calculation methods for blasting and explosion operations is a topical issue in mining industry as they allow to improve characteristics of excavation works and safety of explosion operations. Dozens of scientists offer their design, which reflects the vision of the problem and its solution. There are many methods for calculating the parameters of drilling and blasting, but so far not developed a uniform methodology of calculation, which would encompass all the factors and explained the mechanism of formation of cracks around the explosive charge and the process of breaking rock. The paper presents a novel methodology for calculations for blasting and explosion operations. That methodology comprises various specifics of rock geology and mining engineering during works in horizontal and vertical excavations. In this paper given an algorithm for calculation two main areas of destruction: crushed zone and fracturing zone. In addition, article outlines main aspects of Mining Engineering Development from Antiquity until present days and presents the dynamic of mineral resources.
Determining the Performance of Explosives for Blasting Management
The Mining-Geological-Petroleum Engineering Bulletin, 2022
Experimental methods for determining a performance index of explosives are analysed: the methods of a ballistic pendulum, ballistic mortar, a lead block, and according to the volume of soil explosion funnel. It is defined that the determination of a performance index of emulsion explosives (EE) involves a set of significant features connected with a large critical diameter requiring the experiments with large-mass charges and resulting in refusal from the traditional methods of determining a performance index. Analytical methods for calculating an index of relative performance of explosives are analysed. Determination of the performance indices of explosives with the help of analytical methods helps identify considerable differences in the calculation results; in case of emulsion explosives the results are erroneously low at all. It is since analytical methods do not consider the brisant action of emulsion explosives. This paper represents the developed methodology of determining a performance index of explosives according to the degree of detonation velocity. The proposed methodology considers the key energy and detonation characteristics of explosives: heat and volume of the explosion products, density (thickness), and detonation velocity. The use of analytical methodology for calculating a performance index for all explosive types makes it possible to get correct results that are necessary for designing the parameters of drilling and blasting operations.
Precision Rock Excavation: Beyond Controlled Blasting and Line Drilling
The strictness of the result of an excavation, whether mechanical or by means of explosives, is naturally conditioned by the objective, and therefore by the type of technique applied to achieve it. To attain the best results in terms of rock breakage and respect of the final profile, it’s important to evaluate the excavation specific energy and its optimization. This research focuses on evaluating the effects of different techniques on the quality of final walls in open-pit and underground operations. Different geometries and configurations can be applied to both quarrying and tunnelling blasts. The research is aimed to push contour blasts to their limits, and the main aspects are discussed in order to improve the blast parameters in the daily practice.
A quantitative model for evaluation and classification of blastings in open-pit mines
Journal of Mining and Environment, 2018
By evaluation of the blasting results, a proper blast pattern can be presented. It is, therefore, essential to employ a reliable method to evaluate blastings for the effective control and optimization of the main cycle operations. This paper aims to propose a criterion for evaluating the blasting results such as the fragmentation, muckpile condition, back-break, and fly rock, and to make a possible comparison between the blast parameters including the blasting pattern, explosives used, hole depths, and volume of the blasted rocks in the lead and zinc mine in Angouran (Iran). Using the global criterion, making the decision matrix dimensionless, and defining the appropriate conditions for the results obtained, a scalar value is devoted for the blasts, whose larger values denote a larger deviation from the proper blasting conditions and express undesirable blasts regarding the blasting results. By taking into consideration the mining operation conditions and weights of the results obta...
Acta Montanistica Slovaca:, 2023
Mathematical modelling of rock mass breaking using blasting has been applied to obtain formulas for the calculation of crush zone radii, intensive fragmentation, and crack formation around the charging cavity in the structure, diameter of the charging cavity, diameter of the charge itself, detonation characteristics of an explosive, boundaries of the rock strength, rock mass jointing, and mineral compression under the effect of rock pressure. The methods have been developed to calculate parameters of drilling and blasting operations (DBOs) while driving the mine workings based upon the idea of the arrangement of blastholes in terms of areas they occupy in a fore-breast as well as upon their location relative to break-off outline. Stage one of the methods involves calculating and designing burn cuts where a distance between blastholes is determined with the help of a fragmentation zone radius. Stage two means calculation of both specific and total explosion consumption per borehole bottom, line of least resistance (LLR) for a borehole in terms of intensive fragmentation, areas of borehole groups, borehole number, analytical and actual distance between boreholes, actual charge amount per borehole, and actual specific and the total explosive (E) consumption per borehole bottom. The methods have been tested in the operating ore mine while driving a mine working. Emulsion explosive (EE) Ukrayinit-PP-2 (Україніт-ПП-2) has been applied. The developed methods have been used to calculate DBOs parameters for the explosive. Trial blasts demonstrated the good firing of a borehole bottom and uniform ore fragmentation; a high coefficient of borehole use has been supported. Keywords borehole, emulsion explosive, intensive fragmentation zone, line of least resistance, drilling and blasting operations
International Journal of Mining Engineering and Mineral Processing, 2022
The primary purpose of blasting is to fragment rock, and there are significant rewards for delivering a fragmentation size range that is not only well suited to the mining system it feeds, but also minimizes unsaleable fractions and enhances the value of what can be sold. The outcome of blasting operations is determined by a number of indices or parameters, which can be either controllable or uncontrollable. Methodologies employed in this paper includes mathematical calculation, literature survey, and direct field observations for obtaining specific parameters necessary for analyzing and estimating the size distribution of rock fragments based on Kuz-Ram and Modified Kuz-Ram fragmentation models. We take Direct measurement from Derba Midroc Cement factory which is in Ethiopia's Oromia region of spacing, such as burden, hole depth and stemming length of blastholes. The measurement has been done in the field by using tape measure and the results were recorded in a field note book. The type of explosives used per shot, charging techniques, stemming materials, and fragmentations were all observed directly from the field and photographed for illustrations.
Using seismic methods for defining optimal parameters for blasting
2013
Mining is basic in the process of exploitation of mineral raw materials, whether it is a surface or underground mines. Separate section is the special blasting which must ensure strict, advance superiors conditions. Success in performed blasting depends on the applied method, the rocky massif and quantity of explosives. To determine the method for blasting and the quantity of explosive in the blast holes, it is necessary to know the mechanical properties of the ground: direction of foliation, degree of cracking, Jung modulus of elasticity and other parameters which are used for mathematical modeling to define the position of the blast holes and the optimal quantity of explosive in them. As a proper geophysical method for defining the mechanical properties of the rock complex is seismic method which gave all relevant parameters for successful blasting. Seismic method could be useful applied in defining the explosion zones: zone of thermal influence, internal plastic zone and external...