· Rock mass is a heterogeneous material, and the heterogeneity of rock causes sizes distribution of fragmented rocks in blasting. Prediction of blasted rock mass fragmentation has a significant role in the overall economics of opencast mines. Blasting as primary fragmentation can significantly decrease the cost of loading, transport, crushing and ...
Contact usRock fragmented by blasting follows a different size distribution than the commonly used Rosin-Rammler distribution, especially in the fines range. Sieving data from many different blasting operations have led to a new distribution function, which can describe the fragmentation over the range 1 …
Contact usrock volumes, burdens, etc. 1.9 Miscellaneous Cautious Blasting can be used only for "Types of Blasts" or "Deck" 2. Fragmentation Distribution Following calculations are used when estimating the mean fragment size in the modules "Drilling and Char-ging" and "Fragmentation Distribution…
Contact us· The determination of the grain size distribution of blasted rock exceeds the capability of an analytical sieving machine which only gives reliable results within a range of 63 μm to 125 mm. Other sophisticated methods are often not available for particle size measurement in coarse-grained applications in medium scale mining. Therefore, an alternative low cost method to investigate the grain ...
Contact usThis is a review of the influence of blasting on the size distribution and properties of muckpile fragments. Strong emphasis is put on models that predict how the conditions; geology and rock properties, blasting pattern, charging etc influence the fragmentation in the muckpile.
Contact us· "Blast fragmentation measurement is usually depicted," he explains, "as a particle size distribution (PSD) curve relationship of percentage of rock passing verses rock size." "Quantifying blast fragmentation is useful for measuring blasting performance to determine if the blast has effectively broken the rock mass to enable it to be ...
Contact usblasted rock which weighs 2800 pounds/LCY. Dipper factor is 0.65. 3 93Min 55 2000 / 60min × = × = tonvehicle pounds ton Load Time zAnalyze individual swings of the shovel using 90° pass.. 922 / . 0.65d.f 2800 ./ Hour LCY Hr × × lbs LCY Analyze individual swings of the shovel using 90 • Digging Condition Shovel Loading Cycle: Easy Medium ...
Contact us· The fragment size distribution of blasted rock material is used in the mining industry as an index to estimate the effect of bench blasting. To investigate the influence of rock mass properties on fragmentation in bench blast, the degree and size distribution of fragments within a blasted rock …
Contact us· In this paper, the radial distribution laws of damage factors under decoupled charge blasting are studied for the optimization design of blasting parameters. Through defining the critical radial decoupling coefficient, the damage zone around the borehole is partitioned and the characteristics are described. Based on the damage factor defined by Taylor’s effective elastic modulus, the ...
Contact us· Drilling and Blasting. Drilling and blasting are all about putting the right amount of energy in the right place at the right time at minimum cost to achieve maximum control over the shot rock volume and the resulting particle size distribution in the muck pile
Contact usImpact of Burden and Spacing on Fragment Size Distribution and Total Cost in Quarry Mining ... Prediction of Rock Fragmentation in Open Pit Mines, using Neural Network Analysis. By Kazem Oraee. CSIR-CIMFR. By fazal elahi and Pratyay Saha. IJETR Paper2 February 2020. By Engineering Research Publication and IJEAS. Rock fragmentation control in ...
Contact usRock mass is a heterogeneous material, and the heterogeneity of rock causes sizes distribution of fragmented rocks in blasting. Prediction of blasted rock mass fragmentation has a significant role in the overall economics of opencast mines. Blasting as primary fragmentation can significantly decrease the cost of loading, transport, crushing and milling operations.
Contact usMeasurement of blast damage Introduction Although blasting remains the most inexpensive method of fragmen tation in hard-rock mining, the signifi cance of the costs of blast-induced rock-mass damage in terms of mining efficiency and safety is becoming in creasingly recognized. Blast-damage measurement must account for the
Contact usThe rock unit is the basic mapping unit for the rock material field classification (RMFC) system. It is de-fined as a body of rock that is identified in the field and mapped according to measurable or otherwise describable physical properties or features at a scale useful for project analysis. A rock unit is consistent in its mineralogical composi-
Contact us· In the context of the study, blasting performed in a previously mentioned limestone quarry was investigated, and laser scanning was performed on the blasted rock pile. The particle size distribution of the blasted rock mass was determined by the method presented in this study. An overview of the pile formed after blasting is given in Fig. 13 ...
Contact usThe energy factor describes the energy distribution within a given unit of rock. Energy distribution within a shot is measured by the energy factor, which compares the explosive energy to a quantity of rock broken. The explosive energy distribution within the entire blast is then evaluated along with its resulting fragmentation and
Contact usBlasting generally has two purposes: rock fragmentation, and displacement of the broken rock. The movement of the blasted rock (also known as muckpile) depends on the shot-design ... distribution of the explosive energy, geomechanical strength of rock mass, and confinement
Contact us· Rock from tunnelling and other types of development work has a fine fragmentation. Cut-and-fill mining is a method that normally results in blasted rock with an advantageous size distribution. Block caving on the other hand often results in large amounts of boulders, since blasting of the rock is normally not used.
Contact usdistribution of rock fragmentation by blasting. Rosin-Rammler''s function (1933) was one of the first functions proposed for predicting the fragmentation distribution of fine grain rocks in coal mines [25]. This relation was the basis of many calculations in estimating the size * Trinitrotoluene
Contact usSoil or rock from the borrow expands when dropped on the lorry or the landfill - or stockpiled. One cubic from the borrow does not translate to one cubic dump. Bulking or swell factors for some materials: Material. Density at the Borrow. 103. (kg/m3) Bulking (Swell) Factor.
Contact us· An early experience with the Swebrec distribution (Ouchterlony, 2009a) was that for blasted and crushed rock, R 2 is larger than 0.995 in 95% of the cases, often substantially better. An extension of the Swebrec distribution to achieve a good fit also for the very fine material has been found ( Ouchterlony, 2003b, Ouchterlony, 2005a ).
Contact usOptimization Of Blasting Design Parameters On Open Pit Bench A Case Study Of Nchanga Open Pits Victor Mwango Bowa Abstract: In hard rock mining, blasting is the most productive excavation technique applied to fragment insitu rock to the required size for efficient loading and crushing.
Contact usBlast furnace Slips a Cast house a Sintering Windbox a Sinter discharge a Basic oxygen furnace a Electric arc furnace a 12.6 Primary lead smelting a * Data for numbered categories are given Table B.2-2. Particle size data on "a" categories are found in the AP-42 text; for "b" categories, in Appendix B.1; and for "c" categories, in AP-42Volume II:
Contact usof a piece of particle size distribution of blasted rock mass can be determined by the relation 〈 〉= ∫ r 0 r x B Rdr, where 2 1 2 2 0 B =2π2S (r −r )−. For the destruction zone rr 0 ≤, . by substitution V =πr2, we finally obtain, (5) where К – is the numerical coefficient, which depends on the properties of …
Contact usfor these intact rock pieces, and value of the Geological Strength Index GSI for the rock mass. Intact rock properties For the intact rock pieces that make up the rock mass, equation (1) simplifies to: 0.5 '' '' 3 1 3 1 ci ci m i (5) The relationship between the principal stresses at failure for a given rock is defined by
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Contact us· Meanwhile, it is also commonly observed that joints in natural rock mass are also a kind of fractal distribution. 44 –46 At present, it is a major difficulty to study the particle size distribution of rock mass containing joints after blasting. In this article, the fractal dimension range of two kinds of blasting granular materials, rockfill ...
Contact usall blasting-related injuries in surface and underground mines. Figure 1 also shows the distribution of blasting-related injuries during 1994-2003. Injuries due to inadequate blast area security continue to be a major safety concern. Mitigating techniques for preventing injuries due to inadequate blast area security are discussed in this paper.
Contact usExplosive action of cylindrical charge was studied in an anisotropic rock massif which contain cracks or system of parallel fissures. Sound wave theory was used for qualitative pattern of seismic wave distribution around blasting. Results show changing of seismic waves from round to elliptical shape during distribution through rock massif with cracks.
Contact usA blast fragmentation model is developed based on the gamma function to describe the run-of-mine fragmentation distribution. The model presented is aimed to benefit from simplicity in application and also to be efficient in description of the fine to coarse part of the blast rock fragments. In fact, the gamma based model (KC-KUM), gives a unit distribution curve, which is made up of two ...
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