opencast pillar mining in previously mined underground bord and pillar workings by Ngwenyama1 and de Graaf1 Synopsis South Africa is one of the leading producers and exporters of coal globally A significant amount of the country s production is obtained from previously mined underground bord and pillar workings This
The case studies from the literature showed that bord and pillar mining will reduce the stress interactions in the MG2 mining horizons The 54 geological blocks that can be mined economically allow for bord and pillar mining with a superimposed pillar layout which does not influence the alternative mining horizons
This paper addresses the critical parameters that need to be considered when designing a mechanized bord and pillar mining layout for a narrow tabular steep dipping orebody These parameters are Reef dip Reef width Geological structures within the orebody Physical dimensions of the selection of machines Gradeability of the selection of machines
production rates in Figure 1 probably came about because one section was underperforming for some reason such as excessive ground loss and equipment was moved to supplement production at a section with all eight faces working In the above example the target production is to blast two 12 m rooms every shift Therefore target production is 12 m
Download scientific diagram Percentage extraction of coal at different depths by bord and pillar method from publication Algorithm developed by numerical approach for improving underground coal
In Indian underground mines by conventional mining the loss of coal is more and the safety also less so the many underground mines planning to introduction of the use of the Continuous miner in bord and pillar mining method The Continuous miner technology helps in achieving high production and faster rate of extraction with safety The continuous miners use
production Continuous Miner The continuous miner technology in board and pillar mining is the ideal decision for achieving mass production in underground mines which does not require virgin areas; it can also be applied where development has already been done Continuous miner technology helps in achieving high
2 Room Bord and Pillar mining or continuous mining method It is the most common supported pillar method designed and used primarily for mining flat lying seams or tabular orebodies or gently dipping bedded ore deposits of limited thickness like coal oil shale limestone phosphate salt trona potash and bedded uranium ores Room
Practical mining aspects should be considered when conducting pillar designs for bord and pillar layouts The current methodology for pillar design will result in increasing pillar sizes with depth This affects the extraction ratio and will result in onerous ventilation requirements when cutting large pillars A holistic approach including all mining engineering
2 Risk of overriding of pillars leading to premature collapse in case of bord and pillar workings 3 Low percentage extraction usually < 50% when extraction is done by bord and pillar method 4 Chances of high spontaneous heating because of considerable coal loss in goaf 5 Heavier support requirement in deep seams and longwall method of
2005 Coal production is mainly by bord and pillar mining which accounts for about half of the total production and 90 per cent of the total underground production A problem associated with bord and pillar mining of coal is roof instability One such cause of roof instability is roof guttering in which the roof rock fractures
ABSTRACT Indian coal mining industry is now adopting bulk production technology viz Longwall technology and Continuous Miner CM in Bord and Pillar development along with
Instrumentation and monitoring is undertaken aiming at evaluation of changing values of rock mechanic parameters namely dilation load convergence and stress during mining for a safe strata control It enables the mining practitioners to anticipate roof fall related dangers in advance and taking subsequent preventive measures while depillaring The coal
driven within the pillar for this purpose is termed a "split one split within the Centre of the pillar along the strike and another split of comparable width within the Centre of the pillar along the dip are driven so as that the pillar is split into 4 stooks The splitting may start from 4 middle points of the pillar simultaneously
The various types of coal losses affecting production volumes were investigated When bord and pillar mines reach their end of life coal pillars are inevitably left unmined A forecast can be made as to the feasibility of effective efficient and responsible utilization of the reserves remaining in previously mined out areas Schalekamp
pillars in bord and pillar layouts D Ile1 and Malan1 Synopsis This study explores the use of backfill in hard rock bord and pillar mines to increase the pillar strength and extraction ratio at depth The use of backfill will also minimize the requirement for tailings storage on surface and the risk of environmental damage
The success of mechanized bord and pillar mining in narrow tabular steep dipping orebodies will depend on the extent of the research and development efforts which need to create and innovate
The object of this study is to formulate a procedure for the determination of mining dimensions in bord and pillar workings This is achieved by using the recently reported pillar strength formula which was derived statistically from the results of a survey of mining dimensions carried out in the collieries of the Transvaal and Orange Free State In this study in order to arrive at an
The Bord and Pillar B & P mining method still continues to be popular where deployment of manual miners is more than that of other mining methods The study is conducted at haulage based mine of
