Overburden Stripping Overburden powder factor (kg/m3) 0,46 0,50 0,53 0,59 ratio thickness (BCWROM ton) 2,19 2,45 (m) 33 10,4 70 45 1. Coal seams dipping on average 420. 2. Number of individually blasted benches within overburden. The Queensland and NSW coal mines appear to have the most difficult mining conditions
WhatsApp: +86 18838072829Overburden removal is a major activity of surface coal mining and accounts for over 6070% of the costs. Cast blasting is integral to overburden removal using draglines.
WhatsApp: +86 18838072829The 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.
WhatsApp: +86 18838072829Powder 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.
WhatsApp: +86 18838072829the powder factor, ... Dragline is an HEMM used in coal mining for removal of overburden and dumping it into decoaled area. Failure of dragline contributed to total downtime of 4955 h in 28month ...
WhatsApp: +86 18838072829• Trench depths of 12' to 20': powder factor = • Trench depths over 20': powder factor = Notes: 1 Trench depth does not include subdrilling; hole depth does. 2 In trenches where the overburden is not removed, the overburden is included in the cubic yard calculations.
WhatsApp: +86 18838072829Large surface coal mines in Wyoming's Powder River Basin ship millions of tons of coal per annum, moving millions of cubic yards of overburden to mine the coal. Much of this volume is blasted in the form of benches, a common mining technique. Increases in production and scale of equipment in the past thirtyfive years have created a paradigm
WhatsApp: +86 18838072829The Powder River Basin. The Powder River Basin is a geologic structural basin in southeast Montana and northeast Wyoming, about 120 miles (190 km) east to west and 200 miles (320 km) north to south, known for its extensive coal former hunting grounds of the Oglala Lakota, the area is very sparsely populated and is known for its rolling grasslands and semiarid climate.
WhatsApp: +86 18838072829Panel A coal mining block that generally comprises one operating unit. Panic bar A switch, in the shape of a bar, used to cut off power at the machine in case of an emergency. Parting (1) A small joint in coal or rock; (2) a layer of rock in a coal seam; (3) a side track or turnout in a haulage road.
WhatsApp: +86 18838072829Coal mining has a significant impact on the movement of the overburden, leading to potential safety hazards in the working face. In this paper, a similarity simulation experiment was conducted to investigate the migration of overburden during the mining process of a specific working face in the Liuzhuang Coal Mine located in southern China. Sand and gravel were used to simulate the geological ...
WhatsApp: +86 18838072829EMISSION FACTORS 7/98 Table (cont.). d Multiply the #15µm equation by this fraction to determine emissions, except as noted. e Multiply the TSP predictive equation by this fraction to determine emissions. f Blasting factor taken from a reexamination of field test data reported in Reference 1. See Reference 4. g To estimate emissions from traffic on unpaved surfaces by vehicles ...
WhatsApp: +86 18838072829In 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 ...
WhatsApp: +86 18838072829article{osti_, title = {AMAX draglines dig more overburden with blast casting}, author = {Chironis, N P}, abstractNote = {Two of AMAX Coal Co.'s bestknown surface mines in the Midwest are blast casting to improve dragline productivity even though neither mine has pit conditions that are ideal for casting. The Delta mine at Harrisburg, Ill., and the Chinook mine at Brizil, Ind., are ...
WhatsApp: +86 18838072829Coal shots also g/m3 for overburden and interburdens and 160 to have a lower attenuation due to the depth of the 280 g/m3 for coal. Coal shots use higher powder fac shots, besides attenuation of ground motions with tor to ensure good coal fragmentation and as the distance there is attenuation with depth as coal shots overburden material goes ...
WhatsApp: +86 18838072829Higher powder factor causes oversize and lower powder factor results in crushed rock. Mean fragment size was plotted against the powder factor for 91 blasts of coal overlying overburden benches, as presented in Fig. 22. The general trend shows that, with increase in powder factor, the mean fragment size decreases.
WhatsApp: +86 18838072829Higher powder factor causes oversize and lower powder factor results in crushed rock. Mean fragment Joint plane orientation and spacing size was plotted against the powder factor for 91 blasts of coal overlying overburden benches, as presented in Fig. 22.
WhatsApp: +86 18838072829Powder Factor (Coal) (Te/Kg) = Volume of Block geometry (m3) X Specific gravity (Coal) Quantity of Explosive used (Kg) Calculation of Volume of Block Geometry: Requirements: Surveyor, Measuring tape, Lime powder (Chuna,) 1. Collect the geological information of the patch where powder factor has to be determined. 2. Visit the patch alongwith ...
WhatsApp: +86 18838072829Powder Factor Powder factor (PF) dapat didefinisikan sebagai jumlah bahan peledak yang digunakan dibagi dengan volume hasil ledakan dalam satuan kg/ton atau kg/m3. Definisi lain dari powder factor adalah rasio volume ledakan dengan jumlah bahan peledak yang
WhatsApp: +86 18838072829Where B = breakeven stripping ratio (overburden per ton of coal) in meter 3, R = market price of coal per ton, P = production cost, including cost of mining and preparation but excludes stripping cost per ton of coal, and S = stripping cost per meter 3 of overburden. Coal mining in under Indian scenario, the above ratio is given as :1 at ...
WhatsApp: +86 18838072829thickness of overburden coal seam thickness ground control surface protection requirements • Entry and crosscut widths generally range from 15 to 25 feet • Pillar sizes will generally range from 30 to 100 feet and have a rectangular configuration • Extraction Ratio is the ratio of coal removed compared to estimated in ...
WhatsApp: +86 18838072829Powder 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 ...
WhatsApp: +86 18838072829Coal dumps are also an important factor in the environmental degradation because the potentially toxic elements are directly released to the environment through the leaching and oxidation of pyrite. ... and overburden samples (LOB15A, LOB15B) (dump sites) were collected from the Ledo colliery (India). The coal and overburden samples were ...
WhatsApp: +86 18838072829The correlation was found sufficiently reliable to enable the determination of an optimum powder factor for surface bench blast in different rock types, maintaining the required blasting...
WhatsApp: +86 18838072829Powder factor: Mass of explosives used per BCM rock blasted. Softs: Material that can be free dig or can be remove by mechanical means without the use of chemical energy. Hards: Material that requires chemical energy to break in order for it to be ... The costeffectiveness of removing overburden from the underlying coal seams ("overburden ...
WhatsApp: +86 18838072829The results showed that the optimum hole spacing was no more than m and the powder factor was no more than kg/m 3, and it proved that an effective casting percentage (ECP) of 34% could be realized. 1. Introduction Blastcasting practice in opencast coal mines is characterised by large blast hole diameter and large charges.
WhatsApp: +86 18838072829The Department of Energy's Office of Scientific and Technical Information
WhatsApp: +86 18838072829FACTORS CONTROLLING THE DUMP FAILURES BASIC CONCEPT OF DUMP SLOPE STABILITY STUDY AREA PRECAUTIONS TAKEN FOR DUMP FAILURES 4 5 5 6 9 11 ... The removal of overburden is the first step in a coal winning operation, so as to expose underlying coal for excavation. The overburden material being a waste and nonmarketable
WhatsApp: +86 18838072829The Cenozoicage Makum coal from northeastern India offers numerous research opportunities because of its diverse geochemical and geological characteristics. Due to its high sulfur content, the coal has been found to be less useful for industrial purposes. It can, however, serve as a hub for ongoing research on coalbased derivative products. The aim of this research work is to investigate the ...
WhatsApp: +86 18838072829A 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
WhatsApp: +86 18838072829On a long wall face, the shot holes are drilled at an angle of 45° to 60° to the face; a coal face m high requires 3 rows of shot holes and distance of holes in the same in the same row should be nearly m. Powder factor with solid blasting is to te of coal per kg of explosive and to te of coal per detonator.
WhatsApp: +86 18838072829Like other coalproducing areas, the Powder River Basin has seen mine closures and job losses mount in recent years. Production hit a 50year low in 2020, and 151 coal mines were idled or closed.
WhatsApp: +86 18838072829blasting process measures like the powder factor, the charge length, the amount of explosives used per charge (blast) will be considered and the overburden fragment size will be determined to improve productivity and cost. ... overburden removal. Coal mining processes (in sequence) Top soil removal
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