On 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.
2. u0007For hole firing instantaneously along a row, the KS should be equal to 2; 3. u0007For holes firing on a delay, the KS should be between and and typically between and This is because the blasting is fourdimensional, as timing is a crucial part of the design.
Powder factors Typical powder factors Rules of thumb used in mass blasts Rock type 3PF (kg/m) Hard Medium Soft Very Soft Typical powder factors used in presplit and smooth blasting Hole diameter PF (kg/m2) Hard
The 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.
Coal 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 ...
PT Pacific Global Utama is a company engaged in the coal mining industry. ... plane orientation adalah dip out of face dengan nilai powder factor 0,118 kg/m3. ... material overburden yaitu ...
Overburden at a coal mining site. In mining, overburden (also called waste or spoil) is the material that lies above an area that lends itself to economical exploitation, such as the rock, soil, and ecosystem that lies above a coal seam or ore body. Overburden is distinct from tailings, the material that remains after economically valuable components have been extracted from the generally ...
The Department of Energy's Office of Scientific and Technical Information
To overcome the difficulties of overburden failure and surface subsidence induced by the slicing mining of extrathick coal seams, slicing filler paste is typically utilized. In this paper, a continuous curved beam mechanical model of paste filling mining was established by theoretical analysis against the background of the 3305 working face of Yangcheng Coal Mine, the main controlling factors ...
Full size image. Draw the highwall at angle β, showing the cut width C, the overburden thickness D and the seam thickness T. Draw the two spoil heap faces at the angle of repose, θ, distance C apart. Draw the chain dotted line, xy, at distance = Dx, swell factor, above the base (pavement) of the seam.
the 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 ...
Coal density is among the important parameters for reservoir engineering purposes and is inserted as an input property in simulation studies. Coal density is typically less than that of conventional reservoirs and differs from seam to seam based on the given coal rank and purity [2].The bulk density of a coal consists of the matrix and the void space, with the latter being expectedly filled ...
The 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 ...
thickness 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 ...
Higher 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.
PT Bukit AsamTbk is one of the coal mining companies in Indonesia that uses an open pit mining system. Demolition of B2C overburden rocks at the location of electrification mining in Pit 2 Banko ...
changing the powder factor. The average burdentocharge diameter ratio of 25 to 30 is for average density rocks similar to the typical rocks listed in table 191. Denser rocks such as basalt require smaller ratios (higher powder factors). Lighter materials such as some sandstone or bituminous coal can be blasted with higher ratios (lower ...
The results are plotted graphically and are shown in : Uniaxial compressive strength (UCS) of rock vs Powder factor (PF) It is evident from the figure 7 that the powder factor is increases as the uniaxial compressive strength of rock is increases. Increase in UCS means rock mass is strong which requires more explosive energy to break.
Powder 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
Blasting in Overburden is mainly done either to fragment and shatter the rock or to displace the rock in the mine area by casting of Overburden. According to explosive rules the explosives and their accessories are classified into eight classes. ... (power gel B Navashakti ) 17 Powder factor(o/b coal) O/B2,6ccm, 18 Stemming ...
In this light the present study was conducted in opencast coal mines to see the effect of Schmidt ... Powder factor, Schmidt hammer, Rebound number, Rock mass, Overburden bench *** 1. INTRODUCTION Rock mass comprises several different rock types and is affected by different degrees of fracturing in varying stress ...
Please give me a detailed explanation answer. An overburden of shale will be removed using 200mm holes and 12m benches. Dry rock conditions are anticipated, and the decision is to use bulk ANFO with emulsion cartridges as a primer. The density of compacted ANFO is g/cm3, and the PF (powder factor) is expected to be not less than kg/m3.
holes may be loaded. Threedimensional drillandblast software can pro. vide the designer with tools to interactively categorize. the blastholes that control how the holes are charged and ...
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
Earlier studies also reported that 4 m 3 of overburden is generated per tonne of coal in open cast mining, and the expected amount of 250 Mt of coal will result in 1000 m 3 overburden. For this amount of mined coal, it is reported that, per year, 60 km 2 of land is degraded in mining activity, and about 75 km 2 is used for dumping external rock ...
removing the overburden from the surface of the earth for excavating a mineral resource through creates an opencast mine. An explosive is a solid or liquid substance or a mixture of substances which, in a short period of time after applying a flame, heat or shock (explosion), the mixture
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 ...
Open pit mining method is one of the surface mining methods that has a traditional coneshaped excavation and is usually employed to exploit a nearsurface, nonselective and lowgrade zones deposits. It often results in high productivity and requires large capital investments, low operating costs, and good safety conditions. The main topics that will be discussed in this chapter will include ...
powder factor causes oversize and lower powder factor results in cru shed . ... blasts of coal overly ing overburden benches, as presented in Fig. 22. The . general trend shows tha t, ...
total required drilling, powder factor, and delay times. ANFO and emulsions are the most common explosives agents used in WV surface coal mines, and they are considered in this study. The total drilling and blasting cost is determined. In module III, production rates for hydraulic shovels, electric (rope) shovels, and frontend wheel loaders are
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