>

afecting mining-induced seismicity in a deep tabular mine

The ournal of the Southern African Institute of Mining and Metallurgy VOLM MARCH 2022 115 A case study of geotechnical conditions affecting mining-induced seismicity in a deep tabular mine by L. Scheepers1 and D.F. Malan1 Synopsis Seismic risk in the deep gold mines of South Africa has been studied for many decades. A clear

>

Optimization of blasting in narrow reef mines in South …

Anglogold Ashanti has interests in gold mining ac-tivities across the world as shown in Figure 2. Major gold mines in South Africa lie along an ar c from Jo--west of Johannesburg in a geological location known as the Witwatersrand Super Group. The South Afri-can region of Anglogold Ashanti operates gold mines in the Klerksdorp and Carletonville ...

>

A review of optimal planning of level T and raise spacing …

mining, and sequential grid mining (York, 1999; Ryder and Jager, 2002; Egerton, 2004). The primary demarcation of mining areas or stopes in conventional mining is by means of a grid pattern defined by level and raise spacing. Main levels in conventional mining on inclined tabular reefs have been cut at vertical intervals

>

(PDF) A review of optimal planning of level and raise spacing …

deep tabular gold-bearing reefs of the Witwatersrand Basin, South Africa, Underground Mining Methods: Engineering Fundamentals and International Case Studies, Hustrulid W.A. and Bullock R.L. (eds.),

>

Zondereinde Mine

The UG2 reef comprises three layers of chromitite that are separated by a 15cm thick pyroxenite. The primary member is approximately 80cm thick while the other leading members are on an average 20cm thick. Mining. Typical drill and blast narrow tabular reef mining techniques are used at Zondereinde underground mining.

>

Microsoft PowerPoint

Tabular deposits Flat - <350 dip Wide Reef – Bord and Pillar, Drift and fill Considerations: • Span between pillars • Fill material availability • Subsidence • Geological weaknesses particularly jointing, potholes, triplets, smectites, etc • Depth relatively shallow

>

A hard rock narrow reef mining machine—ARM 1100

based mining to that of continuous non-explosive mining methods has been the dream of many mining engineers. Much of the vast Bushveld Complex has favourable dipping orebodies, mostly in the range of 8 to 13°. This, when compared to the steeply dipping orebodies of the South African gold mines, the bushveld invites the potential

>

Conventional narrow tabular

The conventional narrow tabular mining methods mostly include conventional breast mining, up dip mining, downdip mining and several variations thereof. Access to the reefs and ore bodies …

>

Remnant Mining in South African Gold Mines

A simulated rockburst was conducted underground at Kopanang Mine, previously called Vaal Reefs No. 9 Shaft. The rockburst was simulated by means of a large blast detonated in solid rock close to a ...

>

Mining a Narrow Tabular Reef at Depth with Reference to …

The annual production of 76 tons of gold from 12 million tons of ore treated is obtained mainly from underground sources. Daily some 6.6 km of stope face is blasted and 41 …

>

Chapter 2. BASIC MINING IN.FORMATI·ON

At this point it is important to understand that, for mining purposes, the reef plane is defined in terms of true dip, width and position relative to a grid on the surface of the earth (and a specific …

>

Some rock engineering aspects of multi-reef pillar extraction …

Du Plessis and Talu (1997) described multi-reef pillar mining in a deep-level gold mine in the West Wits Line. The paper highlights the influence of rock type and middling. ... Numerical simulation of a multi-reef tabular mining layout in a South African platinum mine. Proceedings of the First Southern Hemisphere International Rock Mechanics ...

>

Presidential Address: The mechanisation of UG2 mining …

narrow tabular orebody mining method for which South Africa is famous. It is, and has been, widely practised throughout the industry in gold, Merensky reef, chrome reefs, and the UG2. The main advantage of conventional mining is that access to the orebody is in the footwall, so the development, waste can be hoisted separately from the reef.

>

Reef Boring Technology

To accurately drill and ream holes on reef in narrow tabular ore bodies typically found in the South African Gold and Platinum mines. ... By doing it this way there is no need for the blasting of rock with explosives which means that mining can take place 24/7. People are not exposed to high risk areas (on the face) and roof support and scraper ...

>

A Robot Miner for Low Grade Narrow Tabular Ore …

economic at mining heights of greater than 80 cm. The Middelvlei reef is used as an example. In Figure 2, it can be seen that any mining system capable of economically mining reefs at a stoping width of less than 0.5 m significantly increases the reserves from …

>

Loading and hauling of broken rock in a narrow tabular …

This report consists of 2 papers: Report summary & Main article Scraper winch cleaning is well known and widely used in the South African gold and platinum mines to clean the rock from underground ...

>

A Trade-Off Study Between Drill & Blast Operations and Reef …

With increasing depths of mining, difficult reef geologies, reduced overall mine productivity, as well as the increasing cost lines associated with mining in the narrow tabular property; the current blasting related mining methods prove to be less efficient. This is owing to low efficiency, higher effect on the surrounding rock, possible fly rock, dilution, personnel in …

>

Conventional narrow tabular

Conventional narrow tabular The conventional narrow tabular group of mining methods is labourintensive methods with a low level of in-stope mechanisation and are suited to reasonably flat dipping narrow tabular mineralised zones, covering large horizontal extents. Back to underground mining The mineralised zones targeted allow for a mining cut as low as 1.0m, and …

>

A Robot Miner for Low Grade Narrow Tabular Ore …

Initial investigations indicate a significant gold resource in the Witwatersrand that the Robot Miner could unlock with its capability of focusing on low grade narrow ore bodies that are currently un …

>

Mining by rock cutting in narrow reefs

equipment. The move to introduce room and pillar mining into the narrow UG2 reefs is at the expense of mining more waste with the reef; fortunately it appears that appropriate waste and reef separation processes are available. Room and pillar mining followed by long hole drilling and blasting of a narrow slot of reef out of the pillars currently

>

Rockburst support in shallow-dipping tabular stopes at …

date more than 50 000 tons of gold has been mined from this basin14. After more than 100 years of mining, most of the remaining orebody is located at great depth (3 - 4 km depths in some mines). The associated rockbursts and the difficulty of providing adequate ventilation are two of the key engineering challenges when mining at these great depths.

>

Technical operating flexibility in the analysis of mine …

Definition of operating flexibility The New Collins Dictionary and Thesaurus(1989, p. 382) ... different mining methods to (incl. cooling & refrigeration); geological features and allows for selective mining. mine ultra-deep tabular gold reefs. rock engineering stability; logistics; LOM. LSP not flexible for negotiating geological

>

Chapter 2. BASIC MINING IN.FORMATI·ON

CHAPTER 2 BASIC MINING INFORMATION Chapter 2. BASIC MINING IN.FORMATI·ON 2.1 Reef plane description 2 312 A reef plane (or part thereof) in space is described by the following: True dip: This is the steepest average angle at which the reef plane is inclined relative to the horizontal plane (normally at its origin closest to the earth's

>

Optimizing the cut-off grade for tabular gold deposits, …

South African gold mines exploiting narrow tabular reefs face high mining costs, making many of them marginal. The associated mineral resource royalty costs significantly influence the conversion of Mineral Resources to Mineral Reserves when applying an economic cut-off grade (Lomberg and Rupprecht, 2017). Mining

>

TWENTY FIVE YEARS OF MECHANISATION OF TABULAR …

The Background to the Start of Mechanised Mining of Tabular Reefs on the Gold Mines of Johannesburg Consolidated Investment Company. 21 . 2.1 Early Background 25 . 2.2 Arguments for Wide Reef Mechanisation at Cooke 2 Shaft, REGM. 27 . …

>

definition of flat tabular reef in gold mining

The unit "m 2 /month" is typically used as a measure of "volume" of mining as the mined reefs are flat dipping tabular orebodies. The typical mining height varies between 1 and m. The area …

>

GOOD LEDGING PRACTICE

Historically the mining of hard rock narrow tabular reef bodies has been carried out by employing conventional stoping methodologies which rely on ledging as one of the initial operations. The reef is accessed by way of shafts, inclined accesses or addits, and tunnels are then driven (mainly in the footwall) to access the reef.

>

The nature and origin of the Merensky Reef of the …

ally all platinum mining up to about the mid seventies took place on the Merensky Reef of the western Bushveld Com­ plex. The reef has been traced for over 145 km, with current underground stoping and shallow opencast extraction taking place over a strike distance of some 80 km, mainly in the western lobe (Figure 1).

>

Numerical Simulation of a Multi-Reef Tabular Mining …

Two reefs are currently of economic importance namely the upper Merensky reef (a pegmatiodal pyroxenite) and the lower UG2 reef (a chromitite layer). Both reefs are tabular in nature with a …

>

Basic principles for stable gullies in the gold and …

way in which tabular reefs were mined, and stope gullies with scrapers were in use across the industry. This access layout is less prone to stress and rockburst damage, while scrapers in smaller on-reef excavations improved mining efficiency. During the 1980s, some mines introduced trackless Load-haul-dump (LHD) cleaning equipment,