WhatsApp)
Mining at Rajpura Dariba commenced in 1983 and is carried out using the vertical crater retreat method and blasting hole mining method with mined out stopes backfilled with cemented classified mill tailings. In certain areas the ground conditions adversely affect slope stability and dilution.
iii. Vertical Crater Retreat (VCR) Vertical or subvertical blastholes are drilled downward from the top level to the bottom level. A cuboid of orebody can be excavated from the lower level upward by a number of horizontal slices using the same blastholes (Figure 18). Spherical charges should be placed to obtain the maximum cratering effect.
vertical crater retreat mining method customer case. Vertical Crater Retreat Underground Mining Method. Vertical Crater Retreat (VCR) applies to ore bodies with steep dip and competent rock in both ore and host rock. Read more. Underground Mining Methods by sar smith on Prezi.
VRM is a contraction of Vertical Retreat Mining, however it is also known as Vertical Crater Retreat or VCR or sometimes simply called Inverted Crater Blasting. In 1983, it was called an achievement of the last decade and is practiced in mines in Canada, Australia, Europe, Central America, and the
Vertcial crater retreat is a comparatively new method of blasthole mining in which only large diamter ITH holes are used to blast down horizontal slices of ore into an opening below the block of ore being mined. The method on the ''cratering'' effect of an explosive charge being blasted close to the end of the hole.
The Vertical Crater Retreat (VCR) mining method was used to mine two rib pillars at New Broken Hill Consolidated Limited (NEHC) mine at Broken Hill. Experience gained in a trial VCR pillar stope was applied to the design of Panel 3CN pillar (P3CN).
ABHAYA MISHRA VCR MINING Vertical crater retreat (VCR) mining is a method originally developed by the Canadian mining company INCO. Today, VCR is an established mining method used by mines all over the world that have competent, steeply dipping ore and host rock.
CASE STUDY ON VERTICAL. CRATER RETREAT MINING. BY: SUJAN DALBEHERA DEVGAN SINGH 1. ABHAYA MISHRA VCR MINING Vertical crater retreat (VCR) mining is a method originally developed by the Canadian mining company INCO.. Today, VCR is an established mining method used by mines all over the world that have competent, steeply dipping ore and host rock.
#0183;#32;It is one of the main methods for mining coal. It recovers the mineral in slices along a straight line that are repeated to recover materials over a larger area.
Vertical Crater Retreat is compared to other open stoping methods. Various geotechnical factors have been considered including the effects of stress concentration, jointing, dynamic stresses superimposed by blasting vibrations, amount of development required and shrinkage draw. All these factors favour a VCR method in a deep mining environment.
Vertical crater retreat (VCR), both caving and postfill, have been the predominant mining method utilised within the Nkana mine, but is now being converted to a combination of sublevel caving (SLC) and open stoping techniques. Vertical shafts from the surface provide access to
Definition of vertical crater retreat. i. A blasting method employed in underground sublevel mining. Initially a vertical slot extending across the width of the stope is mined. The remaining portion of the stope is then blasted by section into the vertical slot following sublevel procedures. Ref: SME, 1. ii.
Underground mining method Vertical crater retreat (VCR) stopingApplied to the cases where conventional shrink stopingis feasible although narrow orebodywidth (lt; 3 m) may not be tractable, or to the cases where sublevel development is difficult or impossible.Use of long and subverticalblast holes eliminates the need for entry of
Vertical Crater | Mining | Economic Chapter 11. Vertical Crater Retreat: an Important New Mining Method LANG. INTRODUC''I''ION the standard uphole method was used to blast down the The introduction of 165mm (6% in.) holes to 18m (60ft) long section of waste from the bottom underground mining operations has made possible the of the ore into the undercut. application of
Vertical Crater Free download as PDF File (.pdf), Text File (.txt) or read online for free.
Definition of vertical crater retreat mining. A patented mining method in which large, parallel, vertical drillholes permit placement of nearly spherical explosive charges, such that horizontal slices of ore are then broken into an undercut; applicable to ore of only moderate strength.
Vertical crater retreat (VCR), also known as vertical retreat mining (VRM), reduces the cost of mining wide, steeply orebodies. The stope has a similar shape, but instead of small longholes drilled in fans, large blastholes are drilled vertically from a top sill to break through into a
WhatsApp)