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By A. Lyndon

Vertical and lateral load tests were carried out on two 13 m deep bored cast-in-place instrumented piles, socketed into weathered sandstone. The first pile, 1200 mm in diameter, was loaded vertically to a maximum of 16000 kN and then loaded to failure under lateral load (1900 kN). The second pile, 1500 mm in diameter, was tested under lateral load up to a maximum of 2400 kN. It was found that the deflections of the 1200 mm pile were more than twice those of the 1500 mm pile under similar loads. The soils on the site are not easily tested in the laboratory, or by conventional insitu site investigation techniques, parameters needed in design can only be reliably obtained from pile test results. In this report shear moduli are back analysed from the vertical load test and the two lateral load tests. For these similarly installed piles very different design parameters were determined from the lateral load tests, the only known major difference between the piles being that the 1200 mm pile was loaded vertically before it was loaded laterally. Changes in G values needed to match performance under vertical load if applicable to lateral loading could have accounted for a significant amount of the difference.

Jan 1, 1989

By Shachar Magali

This article describes two new concepts regarding the CFA (Auger Cast) piles. The first one, MALI Effect, is an approach to control the casting phase, while the second one, NETA Shear, is a technique which converts the drilling rig into a geo-mechanical tool. We look upon the system of the auger and the ground as a piston inside a cylinder. When concrete (grout) is pumped into that system, an up lift force is generated (We call that force MALI Effect). That up lift force reduces the needed tension in the pull up cable. By analyzing the tension force in the cable we detect the up lift force of the concrete. That pushup force is the product of the real concrete pressure at the bottom of the auger by the area of that bottom. As the area is known, the real pressure is accurately calculated. A control loop which is based on MALI Effect is very sensitive, precise, objective, reliable and easy to be used. All the process is based on pure real physical measurements. The system has no assumptions, no comparisons, no parameters, no zeroing and no adjustments. When we penetrate into the ground like a theoretical screw, for about a meter in depth, and then brake the main cable while rotating the auger, a set of forces generates. As the auger tends to keep penetration, but the cable holds it - a tension force develops (We call that force NETA Shear). Analysis of that tension force shows that it relates to the ultimate shearing capacity of the ground.

Jan 1, 2000

By J. D. Vincent, Paul A. Weyler

Climax Molybdenum's plan for the Henderson 30,000 tpd molybdenite plant didn't just happen. It slowly evolved over a period of 3% years. Many plants cannot afford similar delays, but the Henderson project will take about 10 years to complete from the time the orebody was first discovered until production begins. Pilot plant testing results with both the single stage and two-stage semi-autogenous grinding circuits were highly favorable in terms of operating costs reduction-so much so, that the Amax subsidiary made the decision to go with semi-autogenous grinding for the Henderson mill.

Jan 5, 1972

By M Sparrow

The Victoria Park Tunnel project is an inner-city alliance project in central Auckland, New Zealand. The existing two-directional viaduct will be modified to single-direction flow, and a new northbound 440 m cut and cover tunnel will be constructed beneath Victoria Park. Three-dimensional (3D) visualisation media were used to communicate key design innovations to stakeholders and the general public. The 3D visual material has proven a useful tool for informing motorists of a new safety barrier method adopted for traffic management.This presentation will explain how 3D visualisation was incorporated in the project and will showcase the 3D visualisation media created for the project.

Mar 8, 2011

By F. T. Cawood

This research report was produced in response to the release of the Mineral and Petroleum Royalty Bill. It involved are view of the mineral investment environments of selected countries in order to form an opinion on the appropriateness and competitiveness of the proposed royalty structure for South Africa. Many emerging countries have recently attracted a significant share of foreign investment, as a direct result of changes in policy. These are, by implication, the least risky and most favourable destinations for the ?investment dollar?. The five most competitive countries, namely Chile, Argentina, Peru, Mexico and Brazil have been identified as succeeding with their policy visions of creating favourable domestic investment environments. The investment rules of these countries served as a basis for the compilation of a Competitive Investment Framework (CIF). This is a template of best practice against which other investment environments, such as that of South Africa, can be measured. The framework indicates that mineral royalties should ideally be no more than three per cent, demonstrating that the regime proposed in the Royalty Bill is out of step with international best practice. Mineral royalties can never be viewed in isolation and in the assessment of the rates proposed in the Royalty Bill, one must consider the total taxation package. Such assessment appears in Section 5 of this report, demonstrating that there is reason for concern if National Treasury were to impose the rates stipulated in the Royalty Bill. The alternatives, conclusion and recommendations of the review appear in Sections 9 and 10. These are the result of independent analysis and assessment of the fundamental principles. It is done through the application of a Competitive Investment Framework that avoids the highly subjective and emotional views that often accompany a process like this.

Jan 1, 2003

By Larkin F, Farrer E, McGhie R. R

The Electrolytic Zinc Company of Australasia Limited commenced productive operations during February, 1936, at the- Rosebery and Hercules mines, which are situated near Rosebery, Tasmania. At this time it was decided that before re-organizing the steel sharpening shop a test should be made of the relative merits of conventional drill-steel and detachable bits. For this purpose Ingersoll-Rand type"I" thread centre hole.jackbits were selected and seventy-two of these were tested against conventional steel. Results indicated that, under the conditions pertaining at these mines, j ackbits should prove more economical than conventional drill-steel bits, and that a large-scale test, under working conditions, should be made. This was done by gradually replacing conventional drill-steel with jackbits at the Rosebery mine. Results were satisfactory and by the end of 1936 both mines were using only the jackbits.

Jan 1, 1939

By R H DAVIES

Peak Gold Mine is a new gold and base metal mining project being developed by Enterprise Metals (a 100 per cent subsidiary of CRA) at Cobar in the centre of New South Wales. The Cobar district has a long history of copper and gold mining operations stretching back to the 1870s. Extensive gold and base metal mineralisation was discovered at the Peak in 1981 below a series of gold mines which had been active around the turn of the century. Evaluation of the deposit through the 1980s led to CRA's decision to develop the project for production at a capacity of 450 000 tonnes per annum in late 1992. The project has been developed with a green fields approach despite the long history of mining in the local area. This approach has lead to several innovative ideas being trialed at the site which are expected to result in the operation being a low cost producer of gold and base metals.

Jan 1, 1992

By Takuya Tani, Tomoyuki Aoki, Kazuo Saskai

"The authors have proposed a unique methodology in the evaluation of rock mass stiffness for the range of five to twenty meters ahead of the tunnel face, with the use of small diameter inclinometers. The inclinometers are installed at the tunnel crown at a pre-determined constant interval, about one meter behind the face in order to obtain the slight change in inclination angles during tunnel excavation. This method was developed as a daily control measurement such that the geological condition and its possible change ahead of the face could be detected early by monitoring the trend of inclination angles. This paper describes the results of the ground stiffness ahead of the tunnel face evaluated at a mountain tunnel construction site. This stiffness is evaluated automatically and displayed visually by the current system equipped with a result display screen, together with a warning message against a weak zone when detected. 1. INTRODUCTION In a conventional planning of a mountain tunnel, according to the Japanese Standard (JSCE, 2006) seismic refraction surveys from the ground surface are performed and tunnel support patterns are then designed based on the seismic wave velocity. The resolution of the velocity profile estimated by this technique, however, is poor as the tunnel overburden becomes large. The tunnel face is therefore often encountered by unforeseeable fault zones or weak rocks. Such an unpredictable weak zone occasionally causes the collapse of the tunnel face. Clarifying the forward geological information during excavation is hence significant for safe and well-controlled construction. According to the geological conditions ahead of a face, auxiliary methods typified by forepiling and face bolting could be preliminarily prepared for prompt execution. For the purpose of acquiring forward geological information, pilot borehole drilling and seismic reflection methods represented by the TSP (Tunnel Seismic Prediction) or HSP (Horizontal Seismic Profiling) are often applied. Those exploration are carried out near the tunnel face for a couple of days. This often leads to the interruption of excavation procedure and has no small effect on the construction schedule. On the other hand, some forward ground prediction methods in the daily control measurement have been developed e.g. by Schubert et al. (1995). In this method, tunnel displacements in the direction of the tunnel axis are used together with the crown settlements. We have tested their method at a few of our tunnel projects and found difficulty in the evaluation of the forward ground condition due to insufficient resolution of the axial displacement measured by a total station theodolite that we usually use for the tunnel measurement. We have therefore developed a novel methodology of monitoring slight inclination at the tunnel crown near the face, so that the forward ground conditions can be predicted and evaluated as part of a routine measurement procedure."

Jan 1, 2016

By V. Panayotov, M. Panayotova

"Wastewater from ores processing is often polluted by molybdate and sulfate (SO42-) ions. Sorption is one of suitable methods for removing those pollutants when presenting in low concentrations. This work reports results on adsorption of sulfate and molybdate ions on metal modified (with barium - Ba and lead - Pb) and organic reagent modified (with Hexadecyl-trimethyl-ammonium bromide - HDTMA) clinoptilolite. Zeolite’s modification with Pb, Ba and HDTMA increases its uptake capacity with respect to Mo(VI) at pH 3, with the uptake capacity decreasing in the order CL-Pb > CL-HDTMA > CL-Ba. Lead-modified clinoptilolite shows high uptake with respect to Mo(VI) in acidic, neutral and slightly alkaline conditions. The presence of SO42- in concentrations twice higher than the amount of Mo(VI) do not interfere with the Mo(VI) removal by CL-Pb. Zeolite’s modification with Ba and Pb renders it able to immobilize SO42- from water in the pH range 3-9. Kinetics of the uptake process is best described by the pseudo-first order kinetic equation. Increasing the initial concentrations of Mo(VI) and SO42- increases the removed amount of pollutants. INTRODUCTION Wastewater from copper-molybdenum ores processing is often polluted by molybdate and sulfate ions. Molybdenum (Mo) migrates easily in water and consequently the Mo polluted areas could extend for hundreds and thousands of meters (Ryzhenko, 2010). Molybdate anion is the only Mo(VI) species in natural water, i.e. at pH > 6.0. Its median freshwater hazardous concentration affecting 5% of the species (HC 5.50%) is 38.2 mg Mo/L (De-Schamphelaere et al., 2010). The marine water chronic toxicity (HC 5.50%) is assessed at 5.74 mg Mo/L (Heijerick et al., 2012). The predicted no-effect concentrations (PNEC) are 12.7 mg Mo/L and 1.92 mg Mo/L correspondingly for freshwater and marine water (Heijerick et al., 2012a). When sulfates present in drinking water in excess of 250 mg/L they cause a cathartic action (especially in children) in the presence of sodium and magnesium, and when the concentration exceeds 600 mg/L, diarrhea. When sulfate-rich effluents are discharged into the environment, they may increase the acidity of water bodies and soils (Guimarães and Leão, 2014). Because of the adverse effects to human health and the environment, limits are set for SO42- concentrations in waters and wastewaters in the range of 250 / 500 mg/L."

Jan 1, 2018

By Edward Holloway

The basis for the selection of the ultimate pit for an open pit mining operation is generally opaque. Some form of value-based analysis will generally guide the final decision; however, the value will often gradually plateau whilst the ultimate pit size continues to increase. There is no established framework to guide specialists in the selection of the ultimate pit, with such decisions regularly made on a somewhat arbitrary basis. The key component that is missing from the analyses typically used to select the size of the ultimate pit is risk. Once risk is quantified within the analysis framework, the decision-making range is significantly reduced, and the process for selecting the ultimate pit becomes more consistent, replicable, and defensible. This paper provides an approach to including risk in the process used to select the ultimate pit.

Feb 21, 2024

By M. B. Boyer, C. H. Herty, F. A. Hartgen, G. L. Frear

"DEFINITION OF VISCOSITYViscosity has been defined as the resistance experienced by one portion of a liquid moving over another portion, such as one molecular plane moving over an adjacent plane. A measure of viscosity is the force required to keep one plane in motion at Unit velocity, the other plane being considered stationary. Figure 1 illustrates the general idea that the surface friction between two adjacent areas will be greater the larger the molecules. Therefore it may be assumed that viscosity will be increased by molecular association or agglomeration, and likewise dissociation rill decrease viscosity. According to Maxwell (1)6 the unit of viscosity, the poise, is the tangential force per square centimeter of area of either of two horizontal planes 1 centimeter apart, one of which is fixed while the other moves with unit velocity, the space between being filled with viscous liquid of unit viscosity.The need for a satisfactory apparatus and experimental procedure for the determination of viscosity of high-melting materials at temperatures corresponding to those in pig-iron and steel making has been recognized during the past few decades. The condition of the slag during the smelting and refining periods in the iron- and steel-making processes exerts an important influence on the metal product obtained, this slag condition really meaning the state of viscosity or, vice versa, fluidity, which the slag attains under certain conditions."

Jun 1, 1934

By F. C. Noyes

DAME Nature was in a generous mood when she distributed widely over the face of the globe numerous deposits of phosphate rock from which man can make phosphatic festiIizer to replace the phosphate re- moved from the soil by crops. The principal deposits are readily accessible to the world's greatest consuming areas and most of them are such that mining operations can be carried on at relatively low cost. The world's known reserves shown in Table 1 are sufficient to last well over 2000 gears at the present rate of consumption. Before giving a brief outline of the phosphate rock industry of foreign countries let us try to get a picture of the movement of phosphate rock throughout the world in 1938, the last full normal calendar year where it came from and where it was consumed. Table 2 shows the origin and finial destination of world shipments in 1938 by grand divisions. Table 3 (p. 499) shows shipment9 of phosphte rock to each country in Europe. Europe is seen to be by far the world's greatest market and the French North African mines the world's most important producers outside of the U. S. A.

Jan 1, 1944

By G. T. Lapidus, A. Garcés, O. J. Restrepo

"Colombian nickel laterites have historically been processed by pyrometallurgy. However, due to the depletion in ore grades, alternative processes are required. Hydrometallurgical processes, such as pressure acid leaching, have been proposed as alternatives to extract nickel from deposits with suitable characteristics. Such a leaching process requires high concentrations of acid to achieve acceptable extractions, and is not selective. In this study, an alternative aqueous alkaline glycine system has been employed to evaluate the leaching behaviour of a Colombian nickel laterite which contains 1.15% Ni, 0.12% Co and 41.1% Fe. Additionally, the effect of the addition of chloride ions, the use of a reducing agent and the application of a pre-treatment to improve the extraction of nickel were evaluated. Extractions of 4.63% Ni, 42.16% Co and 0.33% Fe were obtained using a 1M solution of glycine at pH 9. In addition, an increase in nickel extraction from 4.63% to 25.68% was achieved by applying a pre-treatment to the sample. The results show that even though nickel dissolution was much slower than in acid leaching, it was selective over other metals such as iron, proving the proposed method to have potential as a process for the extraction of nickel from Colombian laterites.INTRODUCTION Before 2010, most of the industrial operations used pyrometallurgical processes for the extraction of nickel, mainly in saprolitic regions of deposits, with greater contents of the metal. Nevertheless, due to the gradual depletion of such deposits, different hydrometallurgical processes have been studied as alternatives to process those nickel laterites with low grade and those which present problems of refractoriness due to the presence of acid consuming materials (McDonald & Whittington, 2008; Oxley & Barcza, 2013; Wang et al., 2012). However, such leaching processes require high concentrations of acid to achieve acceptable extractions and they are not selective. Facing lateritic nickel ore deposits containing high levels of acid consuming materials, an alkaline leaching medium becomes an advantageous alternative over acidic media, due to the increase in selectivity and decreased corrosiveness and reagent consumption (Tanda, Eksteen, & Oraby, 2017). Unlike conventional acidic reagents used for metal recovery, alkaline reagents can selectively dissolve the desired metal, leaving in the solid residue other elements such as iron, magnesium and aluminum, which are problematic in subsequent stages of metals separation and recovery. Furthermore, there are no serious corrosion problems associated with alkaline leaching, even at higher reagent concentrations, or at elevated temperature and pressure (Ntumba Malenga, Mulaba-Bafubiandi, & Nheta, 2015)."

Jan 1, 2017

By J. Nielen van der Merwe

Rock engineering research and technology development in South Africa only received serious attention in reaction to the Coalbrook disaster in 1960. At the time, a number of gaps in knowledge of rock related matters were identified and in the ensuing years, these were progressively attended to. The paper describes the events that led up to the Coalbrook disaster and reviews the developments that took place afterwards. The effectiveness of the research outcomes are tested by referring back to the disaster. It is concluded that tremendous advances were made but that not all the unknowns were attended to at the same level. The strength of nominally square internal pillars is the one issue that received the most attention, but the strength of barrier pillars, overburden behaviour and loading systems are still largely unknown. Due to the complexity of the remaining unknowns, they can and should be addressed by the application of back calibrated numerical models. There are no readily available simple analytical solutions. The state of mining rock engineering research in South Africa borders on an emergency. More than a 1000 years of aggregate research experience has been lost in the last three years and funding is under severe pressure. There are disturbing parallels between the current positioning of the industry as a whole and the Coalbrook mine in the years preceding the disaster.

Jan 1, 2006

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who registered at Institute headquarters during the period April 1 to 15. William B. McKinley, New York, N. Y Collier Cobb, Chapel Hill, N. C. C. W. Goodale, Butte, Mont. E. P. Fleming, Guayacan, Chile. D. C. Brown, San Luis Potosi, Mex. Albert Sauveur, Cambridge, Mass. W. H. Rettie, Yonkers, N. Y. H. M. La Follette, La Follette, Tenn. Mark B. Kerr, San Francisco, Cal. E. Fleming L'Engle, New York, N. Y. H. W. Turner, San Francisco, Cal. H. Garlichs, St. Louis, Mo. Frank M. Leland, Mackay, Idaho. Henry Hay, London, England. Sir Robert Hadfield, London, Eng. Edward J. Way announces that his agreement as consulting engineer in South Africa for the Anglo-French Exploration Co., Ltd., having terminated, he will engage in professional consulting work with headquarters at 135 Cullinan Buildings, Simmonds St., Johannesburg, South Africa.

Jan 5, 1914

The use of controlled recirculation can be dated back to the early 1930s. Although this method has been applied in many mines since then, a generalized comprehensive network analysis is still lacking. This paper presents a unique approach in which the ventilation network with a controlled district recirculation is divided into two subsystems: a main subsystem and a recirculation subsystem. The subsystems are analyzed individually and the results and their relationships are then integrated into discussions of the total ventilation system. The analysis of the recirculation subsystem is facilitated by introducing a non-dimensional parameter A, which represents the ratio of the air quantity for the working face to that for the subsystem. As a result, fan and regulator pressures and air power for various recirculation arrangements can be effectively expressed as a function of A and the subsystem air quantity. Numerical examples are included.

Jan 1, 1995

By R. A. Williams

Electrical impedance tomographic methods have been applied to a variety of mineral and chemical processes in the laboratory and on plant. This review paper surveys technical developments in measurement methods to enable quantitative extraction of key process information in the form of mapping of concentration profiles, mixture homogeneity and suspension velocity. The methods for determining velocity are summarized, since this is of especial interest when applied to opaque systems where most conventional optically based measurements fail. A recent significant development is the use of ultra-high speed measurement that now allows velocity vectors to be extracted for fast moving mixtures and fluids (up to several metres per second). New data are reported pertinent to low and high solids concentration flow in pipelines. Use of the methods offer improvements to design of such systems but also points to the use of tomographic electrical sensor as online flow measurement and fault detection. This offers new opportunities for applications and benefits in the design and monitoring of mineral slurries and sludges.

Jan 1, 2008

By Meili Zhu, Qingpu Shi

High temperature, methane, dust and other disasters are getting more serious with mining depth getting deeper and the development of mechanization in underground mines. An application of a descensional ventilation to a coalface is one of the effective measures to solve the above problemes. The descensional ventilation is an venttilation that an airflow in a coalface wouuld downflow along an inclination of a coalface and the direction of the airflow is the same as coalflow. Since 1960's, the descensional ventilation has been applied to 171 coalfaces in 46 coal mines of 23 coal mine administrations in China, such as Pingdingshan , Zhongliangshan, Pubai, Huangshi coal mine administrations. Among the 171 coalfaces, there were 104 coalfaces taking 60.8% in gently inclined seam. The coalfaces in inclined seam and steep seam were individually taking 18.7 % and 20.5 %. There were 77 coalfaces taking 45 % of the total in low gassy coal mines and coal and methane outburst mine were individually taking 17% and 38%. There were 141 coalfaces taking 82.5% of the total in potential danger of dust explosion. There were 125 coalfaces taking 73.1% of the total in potential danger of spontaneous combustion. Therefore, the descensional ventilation can be used in coalfaces under different conditions in China. The practice at home and abroad shown that the application of the descensional ventilation to coalfaces has obvious results in dust control, temperature control, preventing methane accumulation at top corner angle and control of spontaneous combustion in goaf. To more safely and reliably apply the descensional ventilation to coalface and to provide a way for the development of mine ventilation technology in China, the paper will have discussions on the following problems: METHANE EMISSION AND DISTRIBUTION AT COALFACE WITH DESCENSIONAL VENTILATION Methane emission in a coalface with a descensional ventilation is an argued issue for many years. Base on the coal practice, special similar model tests and researches in China, the followings are our main comments. The Descensional Ventilation can Reduce the Methane, Accumulation at the Top Corner Angle. The measurements in six coalfaces with the downward airflow in Qinhemen Mine, Fuxin Coal Mine Administrations shown that the methane concentration at the top corner angle is often up to l% when the coalface has the upward, airflow. The max. methane concentration at the top corner angle is about 0.49 to 0.7% when the coalface has the descensional ventilation. Therefore, with the descensional ventilation, it basically solved the overlimited gas concentration at the top corner angle which is a potential danger to coal production. Because the direction of upfloating gas is opposite to the direction, of the descensional airflow, the descensional ventilation; could increase a turbulent flow mixing capacity of the methan gas and air, and reduce a possibility of methane; accumulation. Due to an air leakage in goat when the coalface with the descensional ventilation lower than an air leakage in goat when the coalface with the, ascensional ventilation, a less methane quantity will release from goat at the descensional ventialtion. It should be pointed out that due to a higher air leakage at ascensional ventilation and the direction of the air; leakage same to the direction of the natural upfloating methane in goaf, those will cause a large methane; accumulation at the top of the goaf and easy bring about, methane accumulation and overlimited methane concentration at the top corner angle with an ventilation vortexflow at the top corner angle. On the other hand, because the direction of the upfloation force function is upward, the descentional ventilation could minimize as possibility of methane accumulation at top corner angle in coal with the descensional ventiltion.

Jan 1, 1991

By N. Ward

The Gualcamayo Mine is located in the Andes Mountains north of San Juan, Argentina (Fig. 1). A property of Yamana Gold Inc., it declared commercial production in July 2009 and has a total mineral reserve and resource base of approximately 88 t (3.1 million oz) of gold. Crushing operations for the openpit mine are located in a 13,500-m3 (477,000-cu ft) underground cavern with a ceiling height of 22 m (72 ft). More than 3,600 m (11,800 ft) of tunnels are used to access the cavern and convey the ore. The project as described in this paper relates to the design and construction of the main cavern, conveyor system exit tunnel, the mechanical system access tunnels and two 4.2-m- (13.7-ft-) diameter shafts (Ore Pass #1 and Ore Pass #2) (Fig. 2). Preliminary engineering for the project was performed by Hatch Chile. Rizzo Associates Argentina, S.A., a division of Paul C. Rizzo Associates, Inc. (Rizzo), was contracted to provide geomechanical and geotechnical support for the construction of the access tunnel system and geomechanical design and construction supervision for the cavern and shafts.

Jan 1, 2011

By M Rauer

With a worldwide growing population the demand for higher living standards, food and the development of new technology is rapidly rising. To allow for a continuous growth, larger quantities of minerals and raw materials are needed at a faster pace. Different methods have been developed to access or tap ore more quickly, such as improved drill and blast operations, mechanical mining methods using equipment such as roadheaders (RH), longwall miners and other technical equipment. Another possibility to access and develop mines faster is the use of a tunnel boring machine (TBM).The historical usage of TBMs is surprisingly long, but the opportunity for technology adoption by the majority of worldwide mining companies remains largely untapped. Dozens of full face TBMs have been used by mines around the world, including two that will begin operation soon in Australia. TBMs have been used to safely and rapidly gain access to the orebody, or to expand access to the orebody to increase output by running a TBM along the edge of the orebody for several kilometres. These machines have also been used for ventilation and for conveyor tunnels for ore removal. They have been used to quickly excavate long and winding declines giving access to an orebody at several levels in a short period of time.Tunnel boring technology can be used for mine declines, mine access tunnels and all sorts of different mine designs and set-ups. TBM technology simply needs to be adapted to the mine conditions and, if manufacturers are involved early on in the planning process for mine development, the operation can be very successful. In some cases, historically typical mine designs may need to be re-thought.One mine, the Stillwater Platinum mine in Nye, Montana, is currently employing its fourth TBM in 25 years. Two were used to create tunnels running alongside the orebody, rapidly expanding access to the orebody in many locations for increased output. Two were used to create parallel access tunnels to a mine expansion at the East Boulder orebody; one tunnel is for conveyor haulage and the other for vehicular access. TBMs have been employed successfully many times to rapidly drive vehicular decline tunnels to multiple mine levels, such as at the San Manuel – Magma Copper mine in the USA. While TBM technology may not seem to be optimal for every mine, these success stories show that the method can provide vast benefits for the right projects.Early use of TBMs in extremely hard rock metal mines, in the 1960s and 1970s, had limited success since performance was low. However there have been great improvements made over the years in the strength of rock which can be excavated by TBMs with high performance. Other important improvements involve the provision of a safe work environment, safely and rapidly supporting the rock and predicting geology ahead of the TBM.This paper will briefly note the more than 20 TBM mining projects and highlight some notable successes. It will then go on to give a status report on the two active TBM mining projects in Australia and the difference between a TBM operation versus other excavation methods such as drill and blast (D&B) or RH excavation.CITATION:Rauer, M, 2014. Tunnel boring machines in mines – a?brief review of past use with a status report on use today in Australia, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 663–670 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014