sbm vertical crater retreat mining methodShrinkage and Vertical Crater Retreat Stoping Oct 23,2014
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A scheme of multiple deck blasting based on vertical crater retreat (VCR) drop-raising method was designed for an abandoned cavity with 30-m cover. The lower 12-m cover was first blasted to ...
Vertical Crater Retreat is compared to other open stoping methods. Various geotechnical factors have been considered including the effects of stress concentration, jointing, …
to improve the stability of Vertical Crater Retreat chambers and Ventilation drives. Among them are, mining the Ventilation drives at not less than 48 meters from the geological footwall contact, mining the Vertical crater retreat chambers at 25.25 meters strike length and supporting them with 6 meters cable bolts and fibre reinforced shotcrete.
Long-Hole Raising and Vertical Crater Retreat (VCR) or Vertical Retreat Mining (VRM) drop-raising are the established blast-hole raising techniques being …
Vertical Crater Retreat stoping. Prof. Dr. H.Z. Harraz Presentation. Shrinkage & VCR stoping. Outline of Topic 5: Shrinkage stoping. Ascending method of mining. Advantages and...
Vrm Vertical Crater Retreat anrexim in. 3 Oct 1983 mining technology A case in point is the most recent innovation in mining methods Vertical Retreat Mining VRM which has led to improved productivity at several of the mines in the Sudbury District Vertical Retreat Mining is a bulk mining method made possible by crater blasting and …
A scheme of multiple deck blasting based on vertical crater retreat (VCR) drop-raising method was designed for an abandoned cavity with 30-m cover. The lower …
This course refers to the generic mining method of sublevel stoping. The most commonly used sublevel stoping mining methods are sublevel open stoping, long-hole open stoping or blasthole stoping, and vertical crater retreat (VCR). Variations of this method include vein (Alimak) mining, transverse stoping, Avoca and longitudinal mining. …
VERTICAL CRATER RETREAT METHOD. The application of this new and revolutionary and mining method has been possible only after down-the–hole drills were introduced to …
Download scientific diagram | -Vertical crater retreat mining method (, 2007) from publication: Possibility of application of backfill methods with cementing fill in ore body Borska ...
This mining method is called Vertical Crater Retreat or VCR which is a blasting method based on spherical charge technology. The main premise is that a column of explosives, no longer than six times its diameter, behaves as a spherical charge on detonation. If the center of a spherical charge is located in a blasthole (drilled …
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 …
The structure, which consists of a series of rings, is on the order of 200–250 km in diameter and was formed about 1850 Ma. The mineralization zone, which formed as a result of impact melting of the upper and lower crust from the impact of a massive meteorite some 14 km in diameter, features in the centre of the complex along with several …
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). Restricted access and a central sandfilled plug in this pillar necessitated the use of angled blastholes and …
Geotechnical aspects of vertical crater mining method in a deep mine S. C. Goel Zambia Consolidated Copper Mines Ltd, Zambia SYNOPSIS 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
A scheme of multiple deck blasting based on vertical crater retreat (VCR) drop-raising method was designed for an abandoned cavity with 30-m cover. The lower 12-m cover was first blasted to investigate the practical blast performance. Charging and timing patterns were adjusted accordingly and the left 18-m cover was
Vertical Retreat Mining (VRM) or Vertical Crater . 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 …
It is better to use vertical stress. vertical retreat mining (VRM), mining methods where the vertical crater retreat blasting method is used. The method is usually used in smaller ore …
It is better to use vertical stress. vertical retreat mining (VRM), mining methods where the vertical crater retreat blasting. method is used. The method is usually used in smaller ore bodies in combination with sublevel shrinkage stoping.
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 …
Faced with rising costs and lower metal prices, several Ontario base metal sulphide mines have changed their method of mining to vertical crater retreat mining. This is a bulk mining method that utilises large diameter holes and mines successive cuts remotely by blasting and cratering the bottom of the drill holes. The orebody is mined from the bottom up. …
Question: Question 6 (15 marks total) An underground mine uses the Vertical Retreat Method (VRM or VCR). Design a blast with a borehole diameter of 160 mm and cratering information (scaled crater volume vs. scaled depth of charge) provided in the following Figure (Figure 1).
The U.S. Department of Energy's Office of Scientific and Technical Information
Synopsis. Vertical Crater Retreat is compared to other open stoping methods. Various geotechnical factors have been considered including the effects of …
Vertical Crater Retreat (VCR) or Vertical Retreat Stoping: configuration method in stopes where drilling large diameter is used to detonate horizontal slices of ore, leading them to …
Vertical crater retreat mining is being used at Zinc Corporation, Limited and New Broken Hill Consolidated, Limited for pillar recovery between previously mined and filled stopes. In order to increase productivity in the older lead lode areas of the mine, particularly in the lower grade sections around the keel of the orebody, score form of longhole stoping was …
Long-Hole Raising and Vertical Crater Retreat (VCR) or Vertical Retreat Mining (VRM) drop-raising are the established blast-hole raising techniques being practiced in various underground ...
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 ...
VERTICAL CRATER RETREAT METHOD The application of this new and revolutionary and mining method has been possible only after down-the–hole drills were introduced to underground mining operations. The method employs large diameter long holes of 152, 165 or 200 mm diameter and is based on the spherical charge technology (also known as …
Vertical Crater Retreat (VCR) or Vertical Retreat Stoping: configuration method in stopes where drilling large diameter is used to detonate horizontal slices of ore, leading them to the base of ...
On the other hand, several blasting technique innovations have also improved the raising safety. In Canada in 1975, mining company INCO developed a mining method based on Livingston's cratering theory. This method is called vertical crater retreat (VCR) or vertical retreat mining (VRM) method.
Vertical Crater Retreat. ... 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.
Long-Hole Raising and Vertical Crater Retreat (VCR) or Vertical Retreat Mining (VRM) drop-raising are the established blast-hole raising techniques being practiced in various underground metalliferous mines for excavating raises [10], [11].
