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vertical retreatment mining method

Vertical Retreat Mining (VRM) or Vertical Crater Retreat

2021-2-26  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 Canada, Australia, Europe, Central America, and the U.S.

Vertical Crater Retreat digistar.mb.ca

Mining retreats horizontally as successive vertical slices are blasted. Vertical block mining is the term most often used for this method. In VBM the workplace is divided into a series of vertical blocks and the blocks may be nined on a retreat basis working from the ends of the workplace.

Vertical crater retreat mining in the Sudbury Basin

Abstract. 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 utilizes large diameter holes and mines successive cuts remotely by

Vertical Crater Retreat Mining Method mode-design

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

Geotechnical aspects of vertical crater mining method in a

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.

A New Fast Vertical Method for Mining Frequent Patterns

Vertical mining methods are very effective for mining frequent patterns and usually outperform horizontal mining methods. However, the vertical methods become ineffective since the intersection time starts to be costly when the cardinality of tidset (tid-list or diffset) is very

Vertical Pit Mining-An Alternative to Open Pit Mining for

2020-6-11  11th International Kimberlite Conference Extended Abstract No. 11IKC- 4686, 2017.pdf Vertical Pit Mining-An Alternative to Open Pit Mining for Massive/Shallow Orebodies P. J. Terbrugge1, R. Armstrong1 1SRK Consulting (South Africa) Introduction The concept of vertical pit mining has developed as an alternative mining method for the exploitation

(PDF) Underground mining Methods ResearchGate

Stull st oping is a common method of to mine vertical or e bodies or steeply-dippin g ore bodies (becaus e the stopes become long narrow near- vertical spaces, whic h, if one

http请求 405错误 方法不被允许 (Method not allowed

2017-8-16  405 Method Not Allowed 请求方法不被允许 今天已上线的项目patch请求 突然报错,nginx没有日志,服务也没有日志。前端捕获到405错误。 历经种种排查 网上方法找了一大堆也没用。 最后发现是移动网络的问题 移动的代理服务器拒绝 patch请求 过了一段

Geotechnical aspects of vertical crater mining method in a

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.

A New Fast Vertical Method for Mining Frequent Patterns

Vertical mining methods are very effective for mining frequent patterns and usually outperform horizontal mining methods. However, the vertical methods become ineffective since the intersection time starts to be costly when the cardinality of tidset (tid-list or diffset) is very large or there are a very large number of transactions. In this paper,...

(PDF) Shrinkage stoping and Vertical Crater Retreat stoping

8. VCR V ertic al Cra ter R etr eat. V ert ical Crater Retreat (VCR) or V ertical Retreat Stoping: configuration method in stopes where drilling large diameter is used to. detonate horizontal

Vertical Pit Mining-An Alternative to Open Pit Mining for

2020-6-11  11th International Kimberlite Conference Extended Abstract No. 11IKC- 4686, 2017.pdf Vertical Pit Mining-An Alternative to Open Pit Mining for Massive/Shallow Orebodies P. J. Terbrugge1, R. Armstrong1 1SRK Consulting (South Africa) Introduction The concept of vertical pit mining has developed as an alternative mining method for the exploitation

Vertical opening safety practice in underground mines

2021-8-17  6 Vertical opening safety practice in underground mines — guideline Foreword This guideline is issued by Resources Safety under the Mines Safety and Inspection Act 1994, and has been endorsed by the Mining Industry Advisory Committee.

Root canal retreatment: a retrospective investigation

Root canal retreatment: a retrospective investigation using regression and data mining methods for the prediction of technical quality and periapical healing Objectives: This study aimed to investigate patterns and risk factors related to the feasibility of achieving technical quality and periapical healing

Sequential Pattern Mining

2016-5-15  • A vertical format sequential pattern mining method • A sequence database is mapped to a large set of Item: <SID, EID> • Sequential pattern mining is performed by growing the subsequences (patterns) one item at a time by Apriori candidate generation

12. Mining methods and method selection

2018-1-30  12.5 Mining method selection-The mining principles and methods have evolved to meet the geomechanical and operational problems of various cases.-Final choice of mining method will reflect both the engineering properties of the orebody and its setting, and the engineering attributes of the various methods such as mining scale, production rate

MINE DEVELOPMENT ACCESS TO DEPOSIT

2012-9-6  The Southern African Institute of Mining and Metallurgy Platinum 2012 101 S.M. Rupprecht MINE DEVELOPMENT ACCESS TO DEPOSIT S.M. Rupprecht University of Johannesburg Abstract A deposit to be mined by underground methods can be accessed by a number of methods: • Adit • Decline or ramp • Inclined shaft • Vertical shaft.

Estimation of the potential production rate

2019-6-28  Estimation of production rate is a problem that has been looked at by many scholars. The most well-known scholar to look at the problem was H. K. Taylor who developed the empirical Taylor’s Rule, which is a rule of thumb that is commonly taught to Mining Engineering students. While the most popular, Taylor’s Rule is not the only method that

A New Fast Vertical Method for Mining Frequent Patterns

Vertical mining methods are very effective for mining frequent patterns and usually outperform horizontal mining methods. However, the vertical methods become ineffective since the intersection time starts to be costly when the cardinality of tidset (tid-list or diffset) is very large or there are a very large number of transactions. In this paper,...

Underground Mining Methods UFRGS

2009-12-7  Underground Mining Methods and Applications FIGURE 1.3 Post room-and-pillar mining mined out Numbers indicate sequence of extraction FIGURE 1.4 Step-room mining of inclined orebody Deposits with large vertical heights are mined in slices. Mining starts

ECLAT: Mining by Exploring Vertical Data Format SlideWiki

ECLAT: Mining by Exploring Vertical Data Format. Vertical format: t (AB) = {T11, T25, } tid-list: list of trans.-ids containing an itemset. Deriving frequent patterns based on vertical intersections. t (X) = t (Y): X and Y always happen together. t (X) ⊂ t (Y): transaction having X always has Y. Using diffset to accelerate mining.

2.4. Mining Frequent Patterns by Exploring Vertical Data

Lesson 2 covers three major approaches for mining frequent patterns. We will learn the downward closure (or Apriori) property of frequent patterns and three major categories of methods for mining frequent patterns: the Apriori algorithm, the method that explores vertical data format, and the pattern-growth approach.

Sequential Pattern Mining

2016-5-15  • A vertical format sequential pattern mining method • A sequence database is mapped to a large set of Item: <SID, EID> • Sequential pattern mining is performed by growing the subsequences (patterns) one item at a time by Apriori candidate generation

LKAB develops a new mining method

The method currently applied in LKAB's underground mines, large-scale sublevel caving, has been very successful. This is an effective method that enables mining of large volumes at a relatively low cost. However, there is some question as to how appropriate this method is for mining at ever greater depth.

Underground Mining Methods and Equipment

2020-8-25  UNESCO EOLSS SAMPLE CHAPTERS CIVIL ENGINEERING Vol. II Underground Mining Methods and Equipment S. Okubo and J. Yamatomi ©Encyclopedia of Life Support Systems (EOLSS) 2. Strength of the hanging wall, footwall, and ore body. 3. Economic value of the ore and grade distribution within the deposit.

Key technologies of drilling process with raise boring

2015-8-1  The raise boring method is suitable for production of vertical or inclined shafts from bottom to top in underground mining operations. Generally, a small-diameter hole, called pilot hole, is first drilled, through which the cuttings fall to the lower level.

Mine surveying: The transition from surface to

2015-8-26  K01 MINING METHOD 07‐Aug‐18 13‐Aug‐22 983 3 324 8 577 8 321 2 085 23 290 K02 MINING METHOD 03‐Sep‐18 03‐Mar‐22 317 1 729 1 459 11 117 533 15 155 Total 04‐Mar‐14 13‐Aug‐22 750 2 595 2 872 4 044 7 802 11 106 16 372 20 443 2 618 68 601 Table 1: Shaft, decline and access development metres.

(PDF) Methods for measuring vertical tire stiffness

Abstract and Figures. Vertical stiffness was measured for a 260/80R20 radial ply agricultural drive tire using five methods; load- deflection, non-rolling vertical free vibration, non-rolling