This method is used when host rock is reasonably competent and orebody is steeply dipping. Broken ore is left in place to support the walls of the stope until all of the broken ore is removed. An important varient of this method is known as vertical crater retreat (VCR) mining. Commodities mined by this method include iron and palladium.

These acronyms stand for vertical retreat mining, which also refers to vertical crater retreat (VCR). This mining method divides the mines into vertical zones having a depth of 50 meters using a bottom-up mining technique. After ore blasting occurs, retrieval will take place at the bottom of the developed section.

3.3. Vertical crater retreat mining method - VCR Vertical Crater Retreat method applies to orebodies with steep dip and competent rock in both ore and host rock. Part of the blasted ore will remain in the stope over the production cycle, serving as temporary support. This mechanized method can be regarded as a considerably safer form of ...

A true vertical crater retreat (VCR) method was used at the Homestake Mine, while a vertical bench mining method (VBM) was used at the Carr Fork Mine. Since there are no personnel in a VCR or VBM stope, all ground control including dimensioning of stopes and pillars and the layout of cable bolt assays or other artificial support must be done in ...

The Pilar UG Mine has previously employed the following mining methods: Sublevel Stoping, VRM and Vertical Crater Retreat ("VCR"). VRM is the method currently employed, whereby ore is removed from the stope after it is blasted and cemented paste backfill is pumped into the mined stopes to ensure geotechnical stability prior to advancing to ...

Crater retreat stoping. ... a system of underground mining using large rooms for extracting multiple levels simultaneously of a vertical or steeply inclined ore vein. Strip mining (Open cast mining) ... a method of stope mining that allows extraction of vertical deposits that are surrounded by competent rock mass (rock that can support itself) ...

By way of an example, using a ring pattern for sublevel cave mining with a toe spacing of 2.7 m (8.9 ft), with a 2.4 m (7.9 ft) burden between rings - with the longest hole in the ring having a length of 30.5 m (100 ft), and using the rectilinear figure, the volume would be 198 m 3. With this volume as common to the other figures, the radial ...

Background. 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 …

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Vertical Crater Retreat. Blasthole mining is a general term applied to mining methods that employ long hole drilling for the production of ore. In most Blasthole methods the ore is blasted into a vertical opening. The blastholes may be small diameter long hole carbide drill holes or larger diameter holes drilled with in-the-hole (IT! drills" or they may be a combination of both.

VCR Method 2018 . MINE 411 Underground Mining Methods Equipment Course Instructor Prof Raymond S Suglo Students UMaT BSc III 1 VERTICAL CRATER RETREAT VCR MINING METHOD The Vertical Crater Retreat VCR method is basically an open stoping method which resembles shrinkage stoping It was developed in Canada Area of Application The VCR method is ...

6) Vertical Crater Retreat (VCR) stoping 8 9. VCR - Vertical Crater Retreat 10. 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 the block being mined.

The name of this method derives from this drawing off or shrinkage of the stope. A modern and important variant of this method is known as vertical crater retreat (VCR) mining. A few examples of commodities mined by this method include iron and palladium. Watch this video (3:01) created by demonstrating sublevel stoping mining method.

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.

H.Z. Harraz Presentation Mining Methods 29 30. 7) Vertical Crater Retreat (VCR) Stoping Vertical longholes are drilled from drives developed in the ore between two levels. Ore is then blasted using a charge that occupies a relatively short length of the hole, some distance from the bottom face. The method has a low explosive consumption. The ...

Mining methods at Mufulira mine The current mining methods used at Mufulira mine are variants of Mechanized continuous retreat (2015). These mining methods (figures 2.1and 2.2) are essentially variants of sublevel open stoping method with delayed hanging wall cave referred to as Mechanized continuous retreat 1 (MCR1)

Vertical Crater Retreat Mining In The Sudbury Basi. 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

Background. 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 …

VRM/ VCR: Vertical retreat mining (VRM) also known as Vertical crater retreat (VCR) is a method where mine is divided in vertical zones [clarification needed] with depth of about 50 meters using open stoping, bottom-up mining.

CASE STUDY ON VERTICAL CRATER RETREAT MINING BY: SUJAN DALBEHERA DEVGAN SINGH ABHAYA MISHRA 1 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. VCR is based on …

MINE 411 Underground Mining Methods & Equipment Course Instructor: Prof. Raymond S. Suglo Students: UMaT BSc. III 1 VERTICAL CRATER RETREAT (VCR) MINING METHOD The Vertical Crater Retreat (VCR) method is basically an open stoping method which resembles shrinkage stoping. It was developed in Canada. Area of Application The VCR method is used in mining steeply dipping …

The vertical crater retreat mining method is also known as VCR mining. This mining method precipitously dips strata for mineralization. This method blasts rocks with total and heavy charges with a large diameter of 165 mm. VCR's blasting creates a cone-shaped opening in the targeted rock mass to let the materials be mined quickly.

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 …

Lecture 51 : Resuing Method of Stoping: PDF unavailable: 52: Lecture 52 : Square Set Stoping: PDF unavailable: 53: Lecture 53 : Vertical Crater Retreat Method â€" I: PDF unavailable: 54: Lecture 54 : Vertical Crater Retreat Method â€" II: PDF unavailable: 55: Lecture 55 : Sublevel Caving â€" I: PDF unavailable: 56: Lecture 56 ...

The blasting test on the vertical crater retreat mining method and the blasting vibration were analyzed. It is estimated if the vibration damage possibly the surface buildings and related facilities of mine. Introduction. The initial design scheme of the Luohe iron mine was sub-level caving mining. In the collapse area, the requisition of lands ...

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 mining (VCR), strip mining and novel extraction methods such as hydraulic mining and borehole mining. Moreover, underground methods such as longwall may be performed in the retreat or advance mode and the ground control may be performed by caving or filling. Therefore choices in the mining method selection process are

There are several methods for bulk underground mining, the most common being block caving, long hole open stoping, sublevel open stoping, sublevel caving and vertical-crater-retreat. 2.2.1 Block Caving Block caving is a large-scale production technique applicable to homogeneous ore bodies of large dimensions and most commonly steep to vertical ...

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. VCR method has been an established mining method …

This presentation will compare various methods of developing these Slot Raises and introduce two new ones. The author begins with a short discussion on the mining method, and its variations, where Slot Raises are used. This mining method is called Vertical Crater Retreat or VCR which is a blasting method based on spherical charge technology.

Vertical Crater Retreat Blasthole mining is a general term applied to mining methods that employ long hole drilling for the production of ore. In most Blasthole methods the ore is …

Crater Blasting. Crater blasting is a method of blasting used in an underground mining method called Vertical Crater Retreat (VCR). Explosive charges are placed in large diameter holes and fired. The concentrated, "spherical" charge is positioned at a specified distance from the horizontal free surface underneath and the detonation creates ...

The thickness varies from 8 to 14 m. The vertical crater retreat method of mining was first introduced at Mindola mine in the late-1980s following several trials that helped define the design criteria for its application. Over the last ten years the method has been continually modified to improve safety and maximise ore production.

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 …