A prognosis methodology for underground infrastructure. For sublevel stoping the ore body and walls should be strong enough to support open stoping. Introduction sublevel caving shields into coal mining was a great advance in. Block caving is an extreme case of sublevel caving in which instead of a back of ore 5 to 10 ft. A stoping method in which relatively thin blocks of ore are caused to cave by successively undermining small panels. Numerical simulation of independent advance of ore. The pebble limited partnership has proposed to mine pebble east using the underground block caving method, which is the cheapest way to mine underground figure 2. In this method, the ore is excavated in open stopes, retreating from one end of the stope toward the other. Underground mining methods are usually employed when the depth of the deposit andor the waste to ore ratio stripping ratio are. Utilization of these roof supports was advantageous. The process of identifying and optimizing a method to mine the block 5 orebody started in 1991, and in 2006 incline caving was identified as being technically feasible. Historical mine data withheld for proprietary reasons for the period 19902000 indicate that buffer mineral reserves have traditionally been maintained at about 4 years with the lor in excess of years. Mar 30, 2018 in sublevel caving slc, the caving of the hangingwall due to ore extraction emphasises placement of the mining infrastructure in the footwall. The randomness in the method of fairfield and leymarie 1991 is not appealing.
The selection of a suitable mining method for an ore deposit requires the consideration of a numerous criteria, such as mininggeological factors, economic factors and miningtechnical factors. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Combining pdfs with a zipper method is useful in a variety of. The ore is then drilled and blasted using longholes between levels, often in a circular or fan pattern, on retreat. A prognosis methodology for underground infrastructure damage. Cavingisthelowestcost underground mining method provided thatthe drawpoint sizeandhandling facilities are tailored tosuitthecavedmaterial andthatthe extraction horizon canbemaintained forthelife ofthedraw. While the footwall in general is less affected by ground settlement compared to the hangingwall, the changes in stress field from mining are significant. Numerical simulation of independent advance of ore breaking. Sublevel caving slc is a mass mining method based upon the utilisation of gravity. Weak rock mass and poor flow of material can cause excessive ore loss and dilution in sublevel caving. By combined use of dimensional analysis and similitude studies in physical modelling coupled with numerical simulation, this paper reports results of a study of gravity flow of muck in.
Maakt het mogelijk om pdfbestanden samen te voegen met een simpele drag anddrop interface. In any discussion of methods of underground mining comparison, one is repeatedly confronted with the difficulty of dealing with so many variable conditions. In order to solve the problem of low production capacity and poor safety conditions of sublevel caving mining at the yingfangzi. Evolution of sublevel caving safety improvement through. This means that continuous excavation works can be ongoing at one sub level without interfering with another. In the settings dialog box, choose a pdf version from the archive format selection box. This article discusses the system details and the impact this system can have on the slc method that is used in many underground mines throughout the world. This method is normally used in massive, steeplydipping orebodies with considerable strike length, and usually has a high amount of dilution and low recoveries. The footwall infrastructure must thus be positioned sufficiently far into the footwall to avoid. A study of gravity flow principles of sublevel caving method. It allows ore economically valuable rock to collapse under its own weight in a controlled fashion. Introduction sublevel caving shields into coal mining was a great advance in mechanized extraction of thick coal seams. Shrinkage mining was a common stoping method prior to mechanised mining and the introduction of hydraulic fill. The simplest method is to use filenew document, and choose the option to combine files into a single pdf.
Block caving is the logical stepup of sublevel caving. Parameters influencing full scale sublevel caving material. This method is usually considered as an alternate to sublevel caving when a lower dilution method is needed and where the rock is fairly competent. About copper mining and mining photo from copper mines in india by n g nair manager mines malanjkhand copper project. Sublevel stoping, cut and fill mining and sublevel caving have generally replaced shrinkage mining in australia, europe and canada. Different failure models are investigated as a function of the orientation of the jointing pattern relative to the location and progressive development of the block cave.
Section 10 shrinkage methods mike turner australian mining. We use cookies to offer you a better experience, personalize content, tailor advertising, provide social media features, and better understand the use of our services. The official publication of the newcastle and hunter valley speleological society. The method is still used in a handful of nonmechanised mines in south america, africa, asia and canada. Glossary in british caving 2 nd edition 1962 an introduction to speleology. This method owes the first part of its name to the fact that work is carried out on many intermediate levels that is, sublevels between the main levels. Mining method selection by integrated ahp and promethee. However, sublevel caving leads to greater dilution and is therefore used for lower ore bodies. Section 10 shrinkage methods mike turner australian. Caving underground mining methods longwall, sublevel caving.
Strength of the hanging wall, footwall, and ore body. Yamatomi encyclopedia of life support systems eolss 2. Sub level caving method block caving mining engineer. Mining method selection by integrated ahp and promethee method. Unesco eolss sample chapters civil engineering vol. Select merge mails into one pdf file under archive method. Caving mines by means of a large 3d physical model.
As compared to other mining methods, sublevel caving allows for a quicker and less expensive mining process. Kvhpm department of mining and mine surveying, royal institute of technology, stockholm, sweden received 1 november 1965 atraetthe following article contains a summary of the results obtained by theoretical calculations, model experiments and largescale. Caving models simulate cave flow for the lifeofmine of a caving operation for several outcomes such as recovery, dilution and production scheduling. International journal of rock mechanics and mining sciences, vol 44, issue 6, pp. The following method uses adobe acrobat pro dc, the best pdf editor you can download. However the general decline in development rates ahead of mining. The ba5 and bb1e blocks figure 2 below the sill on elevations 630 mbs and 732 mbs respectively were changed from postundercut panel retreat caves to advance undercut block caves to reduce the tunnel deformation and failures caused by high abutment stresses on the production level infrastructure, which was developed and. During drawing the shearer is out of operation and is staying at the tail end of the longwall enabling maximum cross section of coal stream in the conveyor pans. In sublevel caving slc, the caving of the hangingwall due to ore extraction emphasises placement of the mining infrastructure in the footwall. Upslope and specific catchment areas are deterministic quantities that we should be able to compute in a repeatable way.
This method of estimating has the added advantage of being unaffected by inflation or deflation since current monetary val. Sublevel caving and block caving underground mining methods presentation pdf available february 2014 with 6,829 reads how we measure reads. After the bottom of the block, or panel, is cut up into pillars by drifts and cross drifts, the pillars are robbed, and then the remaining stumps are. What is the difference between sublevel stopping and.
The mining rate is greater than 20,000 tonnes per day tpd but is usually much greater. Classification of underground mining methods mineral production in which all extracting operations are conducted beneath the ground surface is termed underground mining. This report is advocated towards a layman in block caving in view of getting an impression about the block cave mining method. A study of gravity flow principles of sublevel caving.
Oct 25, 2017 the loss and dilution of ore by sublevel caving mining method is influenced by gravity flow principles of caved granular materials rocks. Gravity flow of broken rock muck in dipping narrow veins is complex. Oct 22, 2014 sublevel stopingunderground mining methods 1. The ore deposit is developed by a series of sublevels spaced at vertical intervals of 18 to 25 ft or 30 ft 5. An underground mining method used in large, steeply dipping orebodies where the wall rock is of an incompetent nature. Pwc open pit mining mining methods 5 open pit mines are used to exploit low grade, shallow ore bodies. It is not an exact science and in the choice of a method each varying factor has a certain weight, which, in many cases, experience alone can determine. A 2d discontinuum modelling approach is utilised based on the distinctelement method. Sublevel caving shields and their utilization in mining out disturbed thick.
Caving underground mining methods longwall, sublevel. Optimum sublevel height and drift spacing in sublevel cave. The second half of the name derives from the caving of the hanging wall and. Block caving is an underground mining method applicable to the extraction of lowgrade, massive ore bodies with the following characteristics. Sublevel caving can be used in orebodies with very different properties and is an easy method to mechanize. Methods of mining include stoping, caving, and various methods of working large deposits which, in addition to the method of actually breaking the ore, require elaborate and definite plans of, development of the orebody. Justintime development model for a sublevel caving. Mechanized under ground mines, mechanized open pit mines.
The loss and dilution of ore by sublevel caving mining method is influenced by gravity flow principles of caved granular materials rocks. Thus sublevel caving is usually used to mine lowgrade, lowvalue orebodies. What is the difference between sublevel stopping and sublevel. The d8 method does well on points 1, 4 and 5, but resolves flow directions too coarsely point 3 introducing grid bias point 2. The second section describes underground mining equipment, with particular focus on excavation machinery such as boomheaders, coal cutters, continuous miners and shearers. Mining method selection is the most important decision made in a mine project. This paper proposes a method to establish design parameters for an inclined deposit within a weak rock mass and evaluates its effectiveness through a case study. This material is intended for use in lectures, presentations and as handouts to students, and is provided in power point format so as to allow customization for the individual needs of course instructors. Jun 25, 2010 sublevel caving technique published on jun 25, 2010 sublevel caving is usually carried out when mining of the orebody through an open pit method is no longer economically feasible. Sublevel caving technique by partha d sharma issuu.
The block model is discretized to blocks of a userdefined size. Thedailyproduction fromcavemining operations throughout theworldisapproximately. Safety issues in sublevel caving the brow, the edge of the intact rock and the broken rock mass, is the area where many safety hazards are present and is the area where hookup operations. The current state of knowledge of subsidence permits a more detailed discussion of longwallinduced subsidence than of the other forms. Shabanie mine is a sublevel caving underground mining operation in zimbabwe. Parallel drives are developed in the ore on equally spaced levels. In this section, the pdfmerger class method is presented. Project sublevel caving was carried out during the years 2009 and 2011, with a budget on 450 million nok. Jun 01, 2010 an underground mining method used in large, steeply dipping orebodies where the wall rock is of an incompetent nature. Apr 21, 20 a new mine planning tool for sub level caving mines gemcom. The append method can be thought of as a merge where the insertion point is the end of the file. Use the mergepdfs method to merge the specified pdf files into a single output file.