Artisanal and smallscale mining asm is a prominent activity in the extractive industry. Chapter three critical technologies for unit operations. Modern drilling and blasting techniques in underground mining. Hole diameters for coal blasting may range from 127 254 mm 5 10 inch. Apr 01, 2016 the dip of the coal seam is 14 in northerly direction. The cycle of operations in surface and underground mining differs primarily by the scale of the equipment. Serbian underground coal mines exist within jp peu resavica coal company. Surfaceblast design this module presents recommended blastdesign practices for surface mine and quarry blasting. Dust and fumes from drilling and blasting of ore present health threats due to poor ventilation. Mar 16, 2015 explosives and blasting in underground coal mi ning 1. Rock fragmentation control in opencast blasting sciencedirect. The elements of a surface mining operation are 1 topsoil removal and storage for later use, 2 drilling and blasting the strata overlying the coal seam, 3 loading and transporting this fragmented overburden material called spoil, 4 drilling and blasting the. During the blasting process, part of the explosive energy. The main difference between tunnel blasting and bench.
Vietnam manufacturing supporting industry yearbook 2016 2017 free ebook download as pdf file. Improved blasting results with precise initiation numerical. In both openpit mines and underground mines, blasting is still the cheapest and most efficient method for breaking rock masses 38, 39. By contrast, in the northeastern united states, hard rock formations exist in a relatively wet environment, where the explosives costs can be as much as 70 percent of the total drilling and blasting expense. Blasting often generates air pressure waves air blast noise. I shut the work down at the end of 1995 because of my departure f rom the bureau. With this method, coal remains confined in all directions from the loaded drill hole, ecept toward the working face. In situ aeration by means of the airflow technology was proposed for landfill conditioning before landfill mining in the framework of a reclamation project in northern italy. The information contained within is not merely limited to use in conducting job safety analyses but can be used when implementing safe operating. Optimization of blasting parameters in opencast mines. Unit operations of mining underground mining and mining. Underground mining methods are usually employed when the depth of the deposit andor the waste to ore ratio stripping ratio are. Blasting primary blasting is the activity in which insitu rock is broken in both development and stoping and in surface mining by drilling holes in the rock, charging them with explosives and detonating the holes in a planned sequence. Economic evaluation of drilling and blasting on the dragline.
Ring blasting is a common production method in underground metal mines. Binary explosive a blasting explosive formed by the mixing of two plosophoric materials, for example, ammonium nitrate and nitromethane. Qgn 11 handling explosives in underground mines department of. Over time, mine management becomes fully reliant upon their explosive suppliers, to the extent that all inhouse blasting. In underground coal mine the yield of coal on an undercut face is nearly 58 te per kg of explosive and 12. Drilling, charging and blasting productivity orica. Australian underground coal and metal mine safety and productivity benchmarks are among the worlds best. Studies are undertaken in everything from the effect of the vibration of the explosion, to the likely impact of the blast on the existent mining structures, prior to the blasting taking place. Types of surface mine, unit operation, basic bench.
Classification of underground mining methods mineral production in which all extracting operations are conducted beneath the ground surface is termed underground mining. Understanding charging and blasting solutions for mines. Severity of the site and blasting handbook offers as when the use of rock minutes to drill for blasting, its implications for example, methods to match the individual explosive in the effects of explosives and a drilling. Blasters training module mine safety and health quizzes.
Economic evaluation of drilling and blasting on the. Blasting blasting operations will be performed by mine personnel on a 7 day per week, day shift continuous. Experience indicates blasting at 1 to 3 blastsday is practical and enables residents to be well prepared for the events. They are safe to transport and handle underground until placed in the drill hole and charged.
Blasting techniques used in underground and opencast mines. The module is an example of the technical assistance the federal government furnishes states to assist them in meeting the requirements of the surface mining control and reclamation act of 1977, upon which their state surface coal mine regulating programs are based. Drilling and blasting technology is one of the main methods for pressure relief in deep mining. The selection of underground mining methods is primarily based on the geologicalspatial.
Improving downstream operational value with oricas experts in underground. These cause rattling of windows and disturbance to sensitive receivers. Ring blasting mine to mill optimization benjamin cebrian. Blasthole drilling this module presents aspects of surface drilling that are important to blasting operations. In general opencut mining occurs in layers as material is excavated over a period of time. In surface mining, the ground covering the coal seam the overburden is first removed to expose the coal seam for extraction. The effects of air pressure waves are addressed by the noise assessment. The blast patterns used in blasting the coal are smaller with smaller diameter holes generally being used. Disciplinary field and drilling handbook pdf, at surface coal mining and. Within the underground mining cycle, the influence of drilling and. Blasting injuries in surface mining with emphasis on. Jan 01, 2019 due to the additional challenges of drilling and blasting in an underground heading, drill accuracy is critical to the success of a smooth wall blast. Primary blasting is the activity in which insitu rock is broken in both development and stoping and in surface mining by drilling holes in the rock.
Blasting in a mine generally occurs in two phases, primary blasting and secondary blasting. In underground mining, blasting becomes one of the primary methods of rock excavation. It is recognized that small scale underground mining in ghana is inundated with unsafe acts and. A method for solid blasting in underground coal mines, which comprises drilling a plurality of shot holes in a development face in an underground coal mine and charging each of the said shot holes with airdecked explosive cartridgesl, characterized in that the said explosive cartridges being airdecked using spacers2 between the said. Blasting delay pattern development in the light of rockburst. Blast plan a written procedure that details the methods and manner by which a project blaster. Drilling and blasting are the major unit operations in opencast mining. Studies are undertaken in everything from the effect of the vibration of the explosion, to the likely impact of the blast on the existent mining structures, prior to the blasting. Proper adoption of drilling and blasting can contribute significantly towards profitability and therefore optimization of these parameters is essential. In turra and purewa bottom, top and combined seams, the average stripping ratio is 1. In underground mining situations, the mine roof conditions, ground support system, and ventilation are important factors in determining the extent of the blast area. In an underground gold mining operation in nevada, blasting in a drift caused a roof fall in another drift situated about 25 ft below the blasted drift. Four prominent small scale underground mines were studied to identify the safety issues associated with small scale underground mining in ghana.
Understanding the connection between blasting and highwall. The hazardous nature of small scale underground mining in ghana. In australia the extent of coal loss from mining operations varies between. Traditional drilling and blasting methods are no longer employed as the primary means of breaking coal in australia, when mining has reached the coal seam. Mining engineering quiz mining engineering multiple.
The main activities carried out at underground coal mines that could lead to emissions to air. Drilling and blasting is the only technology applied in drifting. As the mining process advances forward, the coal seam along with the ob is dumped after the drilling and blasting operations. A highpowered cutting machine the shearer is passed across the exposed face of coal, shearing away broken coal, which is continuously hauled away by a floor. Peculiarities of drilling and blasting in underground smallscale mines. Introduction all seams in underground coal mines are considered gassy, the degree of gassiness may vary from i to iii. With the increase of coal mining depth, a large number of coal mines have entered. Longwall mining is an automated form of underground coal mining characterized by high recovery and extraction rates, feasible only in relatively flatlying, thick, and uniform coal beds. Ore production involves the same drillblast techniques as in normal drifting where drift. To optimize the drilling and blasting process in underground mining.
Mine foreman, and mine examiners certification alone does not provide all the necessary tools to safely perform the duties of a shotfirer in underground bituminous coal mines. This mode of blasting is often termed standup blasting. Citizens guide to coal mine blasting in indiana indiana department of natural resources division of reclamation 8126652207. Drilling machines used in surface mining projects, construction work, etc. The objective of this project was to recover the coal using a payloader and dozer and avoid the reserve from getting wasted.
Ireland synopsis in the early days of underground coal mining, the use of explosives to break coal resulted in a large number of disastrous methane and coal dust explosions and consequential loss of life. Blasting in underground coal mines mining science and. Blasting injuries in surface mining with emphasis on flyrock. However, slc has some disadvantages such as high ore. Msha coal mine fatal accident investigation report. Often, a separate dedicated drill rig is used for coal blasting. Citizens guide to coal mine blasting in indiana indiana department of natural.
Pdf a comparison of advanced computational models and. Generic protocol for loading and firing of explosives in surface mines blasting is a complex activity demanding special skills on the part of the blaster and other crew members. Introduction rock breaking by drilling and blasting is the first phase of the production cycle in most of the mining operations. In general underground mining occurs in horizontal tunnels with access to the surface via large vertical shafts. The inaccuracy of the old underground plans has a major effect on the drilling and blasting performance due to the fact that the pillars were never offset. Opencut underground coal mining facility process diagram. Some companies have even subcontracted all work functions at the mine and processing plant. A good amount of coal is left in the floor of the seam.
The use of emulsion has made blasting significantly safer than it was for the majority of the twentieth century due to their nature as a 5. Underground blasting tunneling there are two reasons to go underground and excavate. The hazardous nature of small scale underground mining in. A 1year aeration project was carried out on part of the landfill with the objective of. Highwall mining is a coal mining method for recovery of outcropped coal by mechanical. A continuous miner with single or multiple augerscutting heads is operated underground and controlled remotely by crew located outside.
For example, in coal and other soft rock mines, continuous miners break and load the mineral to eliminate drilling and blasting. Equipment for large hole production drilling, large scale underground mining symposium, lulea, sweden, november 1985. When the smooth wall holes cannot all be fired on a single delay, the relief is limited to the arch and partially down the rib because of the muckpile. But the principles in sublevel caving blasting are applicable to other underground mining methods. Continuous mining equipment has escalated coal production and introduced more effective and efficient coal handling facilities. The note provides information to be considered during the risk management process to assist in determining acceptable underground blasting practices. In this paper, a six month mine tomill optimization program performed in a cupbzn underground. Underground drilling and blasting training video acg. Introduction serbian underground coal mines exist within jp peu resavica coal company.
A global trend is emerging in which mining companies are subcontracting out the total blasting services including drilling. Landfill aeration in the framework of a reclamation project in northern italy pubmed. Pdf rock blasting in underground mining researchgate. In coal extraction, 25 m of drifts are needed for gaining tons of coal, with 9 m of basic drifts. Safety considerations when blasting off the solid in. Explosives and blasting in underground coal mi ning 1. After blasting, a dragline, shovels, trucks, or other heavy equipment remove the rocky overburden to expose the coal seam. Application and development of an environmentally friendly blast. The mine used the method of shooting off the solid drilling and blasting without using a cutting machine to create a kerf to break coal from the working faces. Karpuz and others published drilling and blasting in coal mining find, read and cite all the research you need on researchgate. Figure 7 shows a preblast model of the coal surface and figure 8 show. The australian centre for geomechanics has developed this safety training video for underground metalliferous mine workers. Drillingandblasting mesh design for underground mining using. In both cases tunneling forms an integral part of the entire operation.
At the request of mike smith, district mining manager in the hawk run office of the padep, i began looking at the blasting problem ear ly in 1994. Arguing that blasting generally is conducted according to rulesofthumb dating back to the 1950s, one supplier noted his firms ability to draw on its database of over 20,000 blast configurations to help mining companies optimize their blasting and re. Modern technology and equipment for tunnel excavation in coal mines and soft rock, mineria chilena nr. A series of numerical simulations of rock blasting using lsdyna software have been conducted to. Virginia coal surface mining reclamation regulations virginia administrative code title 4 agency 25 chapter. Department of the interior, located in denver, colorado. In an underground coal mine the place where explosive is stored in underground is called as. Npi emission estimation technique manual for mining.
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