The most commonly used underground coal mining methods in Australia are longwall and room and pillar Currently almost 65 % of the coal in Australia is being produced by opencast mining methods Mining equipments such as draglines dredgers or bucket wheel excavators trucks and shovels and dozers are the main equipments employed for
A graphical representation of the bord and pillar and mechanized breast mining methods is shown in Figure 1 and Figure 2 It is important to note that the abovementioned methods of mechanization are currently being used only on the UG2 reef horizon Figure 1 Graphical representation of the bord and pillar mining method with 9 bords and
The following methods which are derivatives of the above principle systems have since acquire distinctive nomenclature i Room and pillar ii Level mining iii Horizon mining iv Slicing v Sublevel caving BORD AND PILLAR METHOD Describe the various application of Bord & Pillar method Drivage of Roadways development of mine
September 1967 Journal of the South African Institute of Mining and Metallurgy A method of designing bord and pillar workings — M O G Salomon 69 DESIGN PROCEDURE Basic concepts The statistical analysis has led to the derivation of a formula by which the strength of a pillar with square cross section can be defined in terms of its
Output Per Man Shift OMS of UG and OC mining methods under CIL Source Coal Directory of India FY1998 99 to 2016 17
The document discusses criteria and methods for using the board and pillar mining method in India Some key criteria for selecting this method are seams thicker than at moderate depths less than 60m with strong roof and floor and minimum partings and water A case study describes using this method at a mine with two seams XIII and XIV 8m thick
Continuous miners typically use one of three room and pillar methods to extract coal as follows 1 Pillar Splitting Operators must proceed carefully while transporting coal during room and pillar mining Generally companies use shuttle cars to carry the mined coal from the extraction point to the transfer point Machines then tip the
Applying Numerical Modelling to Pillar Design in South African Mines — An Initial Study K Naidoo University of Pretoria South Africa Handley University of Pretoria South Africa Leach Itasca Africa Pty Ltd South Africa Abstract The use of bord and pillar mining methods is a favoured approach to mining in many shallow tabular mines
In bord and pillar mining a valuable amount of coal is left behind in standing pillars as primary support According to van der Merwe and Mathey 2013 up to Gt of coal has been mined in South 1990s However opencast pillar mining is a complex method and entails multiple challenges compared to virgin coal mining which can adversely
Room and Pillar Method Room and pillar mining is arguably the most important underground mining method in practice today The majority of underground production comes from room and pillar mines and the majority of underground mines by number employs the room and pillar method Think about that
THE bord and pillar method is widely used for coal production in South Africa and has developed in efficiency and productivity in recent years Mining Consultancy Services managing director of Australia Chris Wilkinson says a review of underground mining practices could find bord and pillar conducive to Australian conditions
Room and pillar mining Miners create pillars of ore to support the ceiling as they dig out the rest of the desired material from the space This system may also use a continuous mining system for extracting material instead of personnel Retreat mining This type follows room and pillar mining until mining completes in the room This method removes the pillars for their
arises because no accurate method exists to compute the strength of coal pillars or any other rock pillars for that matter Pillar strength is estimated from empirical formulae which at best can be regarded only as approximate Even the tributary area method of pillar stress calculation is imprecise The ratio of the approximate pillar
A mining method for pillar extraction was introduced at the Pinoura Mine in the South Eastern Coalfields Limited of Bilaspur India in the year 2010 It is a valuable method for the winning of coal resulting in 75% final recovery compared to high capital costs methods longwall mining in a given geomining condition
Role of Bord and pillar Mining A recent study by King1 has shown that despite the increase in relative importance of open cast and long wall mining methods bord and pillar mining is likely to remain the most important method of coal extraction for many years to come Compared with the other methods of coal extraction
Continuous miners operate a room and pillar mining system A series of 18 to 20 foot wide rooms are driven in the coalbed with pillars or columns of coal left standing to help support the roof Roof bolts typically four to six feet long steel bolts are inserted into holes bored into the roof to bind the strata together support the roof
CHAPTER 4 PREVIOUS AND CURRENT MINING METHODS Introduction a Numerous coal winning methods have been used on the mine during its four years of existence The current methods must be judged on the economic factors and their advantages and disadvantages b During the history of the mine rapid variations in seam heights
materials/equipments and environmental considerations The method offering the most Of the unsupported methods room and pillar mining is employed for extraction of popular particularly in non coal mining Gravity can be utilized for ore transportation and broken ore stored within the stope may f unction as a working platform and
The following methods which are derivatives of the above principle systems have since acquire distinctive nomenclature i Room and pillar ii Level mining iii Horizon mining iv Slicing v Sublevel caving BORD AND PILLAR METHOD Describe the various application of Bord & Pillar method Drivage of Roadways development of mine
The bord and pillar mining method has two phases development and depillaring In development a network of roadways is formed separated by coal pillars Then in depillaring the pillars are extracted to remove all the coal This method provides a continuous coal output and supports surface structures but has higher extraction losses and issues with
The paper points out that bord and pillar mining is the most important method of coal extraction in South Af ican underground coal mines and advocates that pillar design procedures should be refined to make more rational allowance for the differences in strength properties between various coal seams and roof and floor strata However any deviations from well established design
