The results proved that powder factor (or specific charge) ranked first in terms of its influence, followed by hole spacing, minimum resistance line, burden, and bench height. ... The coal seam in the second mining districts inclines from North to South with the dip angle increasing. As a result, the bench height for the blastcasting technique ...
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It is also refereed to as coal damage. Chilling is caused during a blast by a combination of explosive shock energy and movement of the more » adjacent rock. Chilling can be minimized by leaving a buffer zone between the bottom of the blastholes and the coal seam or by changing the blast design to decrease the powder factor or by a combination ...
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Powder Factor, q (lb/) Strain Energy Factor, E 15 Fig 1 Nomograph 1 70 50 30 20 10 8 6 4 3 2 3,500 2,500 2,000 1,500 1,000 800 600 500 400 300 90 80 ...
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DUBAI, United Arab Emirates (AP) — The United States committed Saturday to the idea of phasing out coal power plants, joining 56 other nations in kicking the coal habit that's a huge factor in ...
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Indiana Center for Coal Technology Research 1 Brian H. Bowen, Marty W. Irwin The Energy Center at Discovery Park Purdue University ... Indiana Center for Coal Technology Research 22 INDIANA POWDER RIVER BASIN COAL Indiana coal PRB coal Moisture 10 12% ~ 28% Volatile matter ~ 40% higher Heating value 11,386 Btu/lb Btu/lb 8,088
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The blasts covered a powder factor range between and kg/m ³, and were initiated with two significantly different delays, 4 and 23 ms between holes, to assess the influence of both ...
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In this light the present study was conducted in opencast coal mines to see the effect of Schmidt hammer rebound number or transformed compressive strength of rocks on powder factor. The correlation was found sufficiently reliable to enable the determination of optimum powder factor for surface bench blast in different rock types maintaining ...
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Powder factor is simply an economic tool to evaluate various blast designs, as numerous variables will dramatically change the powder factor of the blast to where it can fall anywhere between to pounds per cu. yd. No method exists to accurately calculate a suitable range of ± pounds per cu. yd. that could be applied to a design ...
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A term typically used in coal mining to refer to a separate process of overburden removal, prior to the main pass of the dragline or stripping fleet. Production Blasting. The type of blasting most commonly used in a mine, as distinct from development, trim, presplit, ramp or other special blasts. Powder Factor
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The flow factor ff, defined as f f = ... As one might expect, the most cohesive powder, the hard coal, resulted in the greatest f c,crit and hopper opening size. And the easyflow powder such as brown coal, can produce reliable flow even through the hopper opening size is small. Also, it may be surprising to find that sawdust, which has poorer ...
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Anthracite Coal Combustion General15 Coal is a complex combination of organic matter and inorganic ash formed over eons from ... In PCfired boilers, the fuel is pulverized to the consistency of powder and pneumatically injected through burners into the furnace. Injected coal particles burn in suspension within the furnace
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The powder factor, the maximum charge per delay, and distance from blasting face to monitoring point are the input variables. The peak particle velocity (PPV) is the targeted output variable.
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When the coal powder content reaches 3 wt.%, the surface tension and contact angle of the drilling fluid show more evident changes than other parameters. Based on the analysis of the stress intensity factor, the drilling fluid with coal powders exceeding 100 mesh can reduce the capillary force in microfractures, and in combination with other ...
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Dear students in this lecture we will learn to calculate powder factor, detonator factor and coal production in bord pillar,longwall mining. With basic c...
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Coal blasting is different as coal shots have higher powder factor and tighter burden and spacing to ensure coal fragmentation. For the new B3 Copelmi´s Mine Project, this situa tion could induce an environmental impact with the possibility of generation of higher vibration close to a large community. Attenuation equations were obtained for ...
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Generally, the powder factor value varies from as low as to as much as kg/m 3 with kg/m 3 being the most common, in the open pit mines [ 6 ]. According to the literature, [ 7] the powder factor is considered a fundamental parameter in the selection of explosives.
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The United States committed Saturday to the idea of phasing out coal power plants, joining 56 other nations in kicking the coal habit that's a huge factor in global warming. Special Envoy ...
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The complexities of defining blastability in terms of a powder factor without understanding the fragmentation outcomes are indicated by the very different suggested powder factors for the same compressive strength between data for surface coal mines in Turkey (Muftuoglu et al., 1991) and the powder factors predicted by Mohamed et al. (2015 ...
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According to the correlation analysis, powder factor, charge per delay, air humidity, and stemming have the highest correlation with the dust emission distance. In the dimensional analysis phase, the utmost influential factors in predicting the blastinduced dust emission distance were determined. ... coal mines, quarries, and rock crushing ...
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Forget Powder Factor for Blast Design. Apr 12, 2019 | Feature Articles. Design should be based on economics and blast performance, not an arbitrary range of weight of explosive per volume of rock. by anthony konya and dr. calvin j. konya. When explosives were first used in 1627, blasters and engineers began looking at methods to better design ...
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The coal fly ash concentration has a positive relationship with the acceleration factor. The permeability of crushed coal gangue follows a hierarchical distribution law and the permeability changes in the magnitude range of 1011 ~ 109 m2. ... Shanxi. Xray diffraction spectra of coal gangue powder and fly ash were measured by Xray powder ...
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The powder factor (specific charge) is the mass of explosives bei ng used (kg) to break a cubic meters volume of rock and is calculated using equation 3 below.
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Powder factor can be defined as the quantity of explosives (kg) required to break a unit volume or tonne (t) of rock. The prospect of excavating rocks by blasting is characterized by a specific...
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Powder Factor. Powder factor and the appropriate charging of drill holes is very important in underground mining as malfunctions are very common in the close proximity of loaded holes and the confining environment creating unfavorable breaking conditions. The above equations may be used to estimate parameters of a blast with other known values.
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In this light the present study was conducted in opencast coal mines to see the effect of Schmidt hammer rebound number or transformed compressive strength of rocks on powder factor. The correlation was found sufficiently reliable to enable the determination of optimum powder factor for surface bench blast in different rock types maintaining ...
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Where = mean particle size, cm; A = rock factor varying between and 22, depending on hardness and structure]; K = powder factor, kg explosive per cubic meter of rock; Q = mass of explosive in the hole, kg; and RWS = Relative Weight Strength, 115 is indicates that RWS of TNT but if we use another explosive, we use particular value of the ...
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A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
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