In underhand cutandfill mining, work progresses from the top downward. The second section describes underground mining equipment, with particular focus on excavation machinery such as boomheaders, coal cutters, continuous miners and shearers. Highest percentage of ore recovery, large dimensions of openings to operate high capacity drilling and mucking equipment, safety and economics of huge orebodies exploitation, require establishment of a raining procedure assuring best complying with the above mentioned factors. Ore is high grade and dilution control is critical.
In this method, mining begins at the bottom of the ore body. Underhand cut and fill mining methods are used at the lucky friday, stillwater, and galena mines in the western us in an effort to safely mine in difficult ground conditions and as a primary mining method where access below the ore is limited. Underground mining methods engineering fundamentals and. Other articles where overhand cutandfill mining is discussed. Postpillar design for overhand cut and fill mining in.
For more than 40 years, we have successfully delivered complex, largescale civil engineering and construction projects for many of the bestknown companies in their fields, delivering costeffective results whilst maintaining quality and safety. Minedout stopes are hydraulically backfilled with tailings, and. Cemented backfill mix to be used in a cutfill mining method. The high labor intensity and cost associated with cutting stone makes quarrying the most expensive surface mining method.
Underhand cut and fill mining as practiced in three deep. In overhand cutandfill mining, the most common variation, mining starts at the lower level and works upward. Reliability analysis and design of backfill in a cutandfill mining method jian deng lakehead university, canada abstract in underground mining, hydraulic backfill materials, such as waste tailings, river sand, and cement, are often used to fill underground mined stopes. Cutandfill stoping is applicable to the mining of firm ore enclosed within walls, one or both of which are weak and heavy. The initial stope was mined using the underhand method from the 5,500 level downward on a 70 o dipping vein. Is relatively expensive and therefore is done only in high. Stoping, cut and fill and other underground methods 3d mine scale model of open stoping showing mining induced displacements on a horizontal cutting plane be specialises in application of advanced, multiscale, discontinuum modelling tools to simulate open stope overbreak, access conditions, filling and induced seismicity. Reflecting the international and diverse nature of the industry, a series of mining case studies is presented covering the commodity range from iron ore to diamonds extracted by operations located in all corners of the world. In cutandfill mining methods with blasthole stoping and delayed.
Pdf an overview on the use of paste backfill technology. The rock mass surrounding the ore deposit is also usually weak unable to support loads over an extended stoping height. This method of mining is generally necessary either due to a weak rock mass comprising the immediate back andor high induced back stresses. In earthmoving, cut and fill is the process of constructing a railway, road or canal whereby the amount of material from cuts roughly matches the amount of fill needed to make nearby embankments, so minimizing the amount of construction labor.
The method has evolved at each mine to meet the unique situations associated with their milling procedure. Generally, designers generate drawings called cut and fill diagrams, which illustrate the cut or fill present at any given site. Mining method, underground mining, roomandpillar mining, sublevel stoping, cutandfill, longwall mining, sublevel caving, block caving, backfill. Overhand cut and fill mining method is used in steeply dipping ore bodies in strata having a relatively weak strength and comparatively. Successful ucf mining is dependent on cemented backfill. In this latter case cement must be added to the fill to form a strong roof under which to. Cut and fill welcome to the narrowvein mining project. This book presents the latest mining principles and techniques in use today. The goal was to recover ore beneath the lowest level of the mine in an area where rockbursts had occurred and ground conditions were very poor. In underground mining, hydraulic backfill materials, such as waste tailings, river sand, and cement, are often used to fill underground mined stopes.
Its disadvantages, on the other hand, are as follows. Selective mining, such as post pillar cut and fill, is used in large, flat, irregularly shaped ore bodies where ground stability is to be maintained. Mining in minnesota cut and fill mining method 3d animation for more information and to request a free estimate, contact us today. This selective mining is used to open the stope to the full lateral extent of the ore body in order to minimize the dilution and maximise the recovery. Together with roomandpillar mining, it is the most flexible of underground methods. Mechanized cut and fill mining refers to cut and fill stopes that are accessible by rubber tired equipment from the regular mine access development. Development in the ore of the upper and lower drift. The cutandfill mining method at black mountain is a result of research and planning activities that included the use of modelling, laboratory tests, mathematical analyses, in situ tests, and experience gained from other mining operations. Highwall mining is a coal mining method for recovery of outcropped coal by mechanical excavation without removal of overburden.
These investigations and the resulting developed methods and designs are summarized in the paper. This drawing is quite standard, being no more than a graph with site location on the xaxis and fill being the positive range of the yaxis while cut is the negative range of the yaxis. Post pillar cut and fill stoping at the dolphin mine of. In steeplydipping ore bodies, such as lodes of tin, the stopes become long narrow. Underhand cut and fill is a versatile mining method. The uppermost sublevel underneath the cover is partly caved. It is used to fill underground voids where the ore has been extracted, either to provide a working platform from which the next slice of or can be extracted.
A schematic of the multislice cutandfill mining method is depicted in figure 5, with respect to this method. Mining in minnesota cut and fill mining method 3d animation. Mill mixed with cement forms weak concrete when poured into the mined out stope. Mechanized cut and fill stopes can be very productive with stope widths in excess of 40 m in good ground conditions and stope lift heights of 4. Mining in minnesota cut and fill mining method 3d animation duration. So, the cut and fill process is typically one of the first construction processes to take place on a site. Pillars are left inside the stope to support the roof. The value of the ore makes recovery of economically viable. Excavation and embankment cut and fill excavation the removal of soil or rock from its natural location.
Underhand cut and fill has been particularly successful in rockburstprone areas. Initially drilling and extraction drives are mined along the ore length and width. It is an expensive but selective mining method, with low ore loss and dilution. Cutandfill stoping is a preferred method for high grade ore bodies with a steep dip size or irregular shape or vein structure. The ore is mined in horizontal or slightly inclined slices, and then filled with waste rock, sand or tailings. Reliability analysis and design of backfill in a cutand. The mining rate includes the mining of both waste and ore. Pdf underhand cutandfill stoping is an efficient, sustainable mining method that is particularly applicable to complicated mining conditions.
The deposits may be tabular in form, dipping at angles steeper than the angle of repose of the broken ore or flatter, if scrapers are employed for moving the ore in the ore passes, or to wide, thick ore bodies or masses. Its characteristic feature is the use of sublevels. Drift and fill the high value, high recovery mining. The drift and fill method can be applied to a variety of underground mining situations and is a preferred method for some orebody geometries and where ore recovery is viewed as a key to project success.
Ni 43101 technical report for the nevescorvo mine, portugal june 2017 prepared by. In cut and fill mining method, as the mined voids are backfilled with waste rock or tailings, the surface subsidence due to mining operation can be controlled and. Decmil our founding construction and engineering business was established in the pilbara region of western australia in 1978. Cut and fill, drift and fill the rock quality designation is a further critical factor. In cutandfill mining, the ore is removed in a series of horizontal drifting slices. The need contacts between ore and waste are structurally critical but not readily visible. Galena mine with the introduction of mechanized underhand cut and fill mining. Sublevel stoping, vertical retreat stoping, sublevel caving, and cutandfill mining are methods that usually can be applied under similar conditions. Excavated rock is taken to the surface with gold ore taken to strathalbyn and rock without gold mullock is stored on the surface before being progressively returned to the mine to fill the excavated voids.
It is most useful in ore where the wall rock or vein is unconsolidated and cannot be safely mined using traditional cut and fill. Remove ore in horizontal slices, starting from a bottom undercut and advancing upward. Gold quartz veins in a hardrock gold mine, stoping and mucking mbmm duration. In cutandfill mining methods with blasthole stoping and delayed backfill, after extraction of adjacent pillars that contain economic minerals, the backfill is often subject to exposure of free standing on at least one side.
The volumes can be computed for respective sections and then summed together. Cut and fill mining is a method of shorthole mining used in steeply dipping or irregular ore zones, in particular where the hanging wall limits the use of longhole methods. As a mining method cut and fill is ideally suited to the extraction of ore from narrow steeply dipping orebodies, from orebodies with irregular contacts or outlines. The post pillar cut and fill stoping method has been adopted by king island scheelite for the extraction of the main dolphin orebody. This system can be adapted to many different ore body shapes and ground conditions. Ore zones are large, but their rock quality is weak.
With this method, ore is recovered in horizontal slices starting from the bottom and advancing upward. Cut slopes are rarely created greater than a slope of two to one horizontal to vertical dimensions. This paper examines some of the critical mine planning and backfill issues involved with the drift and fill mining method. Overhand cut and fill evolved from square set stull stoping to provide stronger support. A mining method involving overhand, underhand, and shrinkage stoping. Overhand cutandfill mining mining method britannica. It is a versatile method that provides high ore recovery and is suitable for deposits that require mining ore out of selected ore pockets.
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