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By Leroy G. Hagenbuch

"IntroductionAn integrated Truck Management Information System (Truck MIS) evolves as seemingly separate functions combined to yield a single homogeneous result / product. The concept of a computer integrated Truck MIS includes truck dispatch, truck maintenance management and truck weighing.A truck management system is only as good as the information / data bases input to it. The concept of an integrated system works best with automated data gathering. Automated data gathering provides timely and normally, the most accurate historical information/data bases. Data bases are, however, historical, which is a problem to be overcome in a computerized truck management information system, especially in regards to a truck dispatch system as loading sites / loading conditions and some dump site conditions continually change. As these changes occur, data base s must change as well, and thus the need for the continual update of data bases that the computer uses for a Truck MIS.For a truck dispatch system to achieve reliability / viability, dispatch decisions need to revolve around real time data gathered in an automated way. Integration of all truck management function s through automated data gathering lead s to the best over-all system.An integrated system is a combination of many different factors and is only as good as each factor / building block put in the system. With the proper building blocks, an integrated Truck MIS is very feasible - an MIS System that includes weighing, time and motion study, truck maintenance and maintenance management, as well as truck dispatch.Truck MISAn integrated Truck MIS provides for truck dispatch as the ultimate end result, a truly automated /integrated truck dispatch system (to function non-operator-dependent). The following comprises its central building blocks:-Time.- Haul Cycle Segments.Truck Status, i.e. Load on truck,- being loaded,- loaded,- unloaded,- in service,- out of service.- Vehicle Location.Loading Equipment Status.- in service,- out of service.Optional- distance travelled in each haul segment.With this data provided on a non-operator dependent basis, it is possible to build good data bases so a computer can make truck dispatch decisions. Knowing what information is needed as the central core to a good Truck MIS, how can this information be automatically gathered and fed into a central control computer?"

Jan 1, 1986

By M. S. Safarzadeh, V. Agarwal

"The solvent extraction of cerium(III) and samarium(III) from mixed solutions of all rare earth elements (REEs) except promethium using PC88A (2-ethyl hexyl phosphonic acid mono-2-ethyl hexyl ester), an acidic extractant, was investigated. The effects of aqueous equilibrium pH, various acids (sulfuric acid (H2 SO4 ), hydrochloric acid (HCl) and nitric acid (HNO3 )), initial metal ion concentration and extractant concentration on the solvent extraction of Ce(III) and Sm(III) were systematically studied. From the experimental results, HNO3 and HCl were found to be the preferred aqueous media for the solvent extraction of both Sm(III) and Ce(III). The most promising experimental conditions of pH, PC88A concentration and metal ion concentration were identified for the extraction of Ce(III) and Sm(III). Separation results showed that H2 SO4 at pH 2 provided the best separation between Sm(III) and Ce(III). IntroductionIn recent years, demand for rare earth elements (REEs) has increased significantly because of their many commercial applications. REEs have especially important high-tech applications owing to their unique physical and chemical properties, and they are used in a wide range of areas such as catalysts, ceramics, magnets, lasers, glass, neutron absorption and alloys. As REEs have very similar physicochemical properties, their separation and purification from each other is challenging and gaining significant interest. Samarium (Sm) and cerium (Ce) are found in different REE minerals, including bastnäsite ((Ce,La,Nd(CO3)F), xenotime (YPO4) and monazite ((Ce,La,Nd,Th)PO4) at major production sites in the United States and China, as listed in Table 1 (Bleiwas and Gambogi, 2013). The most common acidic organophosphorous extractants used for REEs extraction and separation are DEHPA (di-(2-ethylhexyl)phosphoric acid), PC88A (2-ethyl hexyl phosphonic acid mono-2-ethyl hexyl ester), Cyanex 272 (bis-2,4,4-trimethylpentyl phosphinic acid) and Cyanex 301 (bis(2,4,4-trimethylpentyl)dithiophosphinic acid) (Sarangi, Reddy and Das, 1999; Surampally et al., 2012; Tian, Jia and Liao, 2013). Out of these extractants, PC88A is known for providing higher separation factors (Acharya, Mishra and Misra, 2015). El-Hefny et al. (2010) investigated the kinetics of the solvent extraction of Sm from chloride media using sodium salt of Cyanex 272 and reported the extracted species to be Sm(OH)A2•2HA. Lee et al. (2005) investigated the solvent extraction of Sm(III) with PC88A and saponified PC88A from chloride solutions and found the stoichiometry of the extraction reactions to be 1.5 with PC88A and 3 with saponified PC88A."

Jan 1, 2017

By P. Linzer, L. M. Linzer

The gravity method is often applied in mining-related scenarios such as geological and mineral exploration, detecting subsurface cavities and voids (“receptacles”) that may become sinkholes, siting of surface structures, fault-mapping, and more. It is also widely applied in geotechnical engineering to map subsurface karst profiles and to detect subsurface cavities, such as can occur in open pit mines. While it is widely acknowledged that, compared with other available geophysical methods, this method is the most applicable to the karst profiling problem, survey geometries applied in the field are often far from optimal. The gravity surveying specifications prescribed in SANS 1936 omit some key requirements for optimal survey outcomes, and this paper is intended to fill those gaps. The authors have seen scopes of work that require only a few measurements over the footprint of a proposed structure, indicating a lack of understanding of the nature of the gravitational field. A single gravity measurement is subject to the camouflaging effects of several influences, many of which can be larger than the anomaly caused by the subsurface density variation itself. Papers in the body of literature show an awareness of the need to map the regional field so that it can be subtracted to unmask the residual gravity anomaly, but rarely do they examine how instrument sensitivity governs the size of detectable anomalies or discuss how a detailed terrain correction can be instrumental for isolating faint targets. This paper aims to explain how to apply the gravity method correctly to mining and geotechnical problems, specifically in the detection of subsurface cavities. It discusses various factors to assist with optimising the acquisition of gravity data and its processing so as to maximise the practical value of gravity surveys.

Sep 1, 2025

By Iain M. Mason

Linear meridional zones of bad roof conditions have been frequently encountered in producing collieries working the Permian age Lithgow seam in the western coalfield of New South Wales. The prediction of such zones ahead of mining is desirable for reasons of both safety and economics. In March, 1981, we carried out an experimental, three-component in-seam seismic survey at Invincible Colliery to discover whether such zones have any unambiguous seismic effect. The underground survey was the first of its kind to be attempted in an Australian mine. The data quality was excellent with the spectra broadband and clear. Polarisation analysis disclosed two modes: one compressional; the other shear horizontal. The SH model was clearly dispersive and well gound to the plane of the seam. Modal velocities decreased by up to 15% at the fracture-swarm site. There is a strong suggestion on the RLS maps obtained here that the distributed fault zone is acting as a composite scatterer of channel waves. The P-SV and SH wave tomograms obtained show, in a general way, the distribution of stress in the coal panel.

Jan 1, 1982

By J. B. Hedrick

Rare earths were not mined in the United States in 2008. However, processing of intermediate rare-earth concentrates continued throughout the year at the Mountain Pass Mine in California. Consumption of refined rare-earth products increased. U.S. rare earth imports were primarily from China, with lesser amounts, in decreasing order, from France, Hong Kong, Japan, Austria and Russia. The United States imported 100 percent of its supply of yttrium metal and compounds primarily from China. United States In 2008, lanthanide concentrates were processed by Chevron Mining Inc. (previously Molycorp Inc.) at its mine site at Mountain Pass, CA. Chevron Mining sold its entire holdings in the rare earths mine to Molycorp Minerals LLC in September and operations continued at the site through-out 2008. Major uses for these mineral commodities were in automotive catalytic converters, petroleum fl uid-cracking catalysts, permanent magnets, glass-polishing compounds, ceramics, metal-alloying additives, phosphors and recharge-able batteries. Three domestic companies produced and sold lanthanide intermediate concentrates and refined products. Chevron Mining sold its interests in the Mountain Pass Mine to Molycorp Minerals LLC on Sept. 30, 2008. Molycorp Minerals LLC is an investment company owned by Resource Capital Fund IV L.P., Pegasus Partners IV, LP, The Goldman Sachs Group Inc., Traxys North America LLC, Carint Group LLC and Mark Smith. The Molycorp operation previously mined the rare earth fluocarbonate mineral bastnäsite by hard-rock surface methods, and the mine remained on care and maintenance in 2008. Molycorp maintained significant stocks of bastnäsite concentrates, intermediate concentrates and high-purity rare earth compounds at its operations at Mountain Pass. In October 2007, Chevron Minerals completed phase one of its three-stage plan and restarted the rare earth separation plant at Mountain Pass. The company also processed intermediate rare earth concentrates from existing stocks during the first three quarters of 2008. Molycorp Minerals LLC maintained production in the last quarter of the year. The mine at Mountain Pass has been closed since 1998. Future plans are to restart processing of stockpiled bastnäsite concentrates followed by reopening of the mine.

Jan 1, 2009

By S. E. Daniel

"Due diligence reviews are an essential part of mineral property acquisitions. One of the primary reasons to complete an environmental review prior to exploration property acquisition is to assess the potential environmental liability. It is critical to identify the potential reclamation costs or existing environmental liability associated with the exploration property. A review of the existing condition of the property and its history can allow prioritization of exploration targets and ease future expenditures for historic damages. IntroductionIn Canada and some other jurisdictions, the purchaser of a property is assumed to know, and is (in the absence of deceit or fraud) financially responsible for, what is purchased. A plea of ignorance, at least from the perspective of environmental liability, is not an acceptable excuse to avoid responsibility (Nelson, 1994). Therefore, if an exploration company (for the purposes of this paper, any organization conducting exploration work) purchases a property that has environmental contamination, the new owner is liable for the cost to reclaim the site to an acceptable level. The cost to reclaim the site is the environmental liability. The new owner is responsible for existing environmental liability of the property, even if the exploration company’s personnel were not aware of the problem. In simplest terms, buyers beware. Therefore, in order to protect the exploration company’s interests, the exploration manager should determine the characteristics of the property of interest prior to purchase or other involvement, and exercise due diligence.The term “due diligence” is often used in the mining industry. To ensure clarity, in this paper’s context, the author has chosen to use the following meaning: “… due diligence is used to describe a detailed data review, generally in connection with the purchase or sale of a mineral property, the approval of a large capital expenditure, or the borrowing of a large sum of money” (Smith, 1997).Directors of the exploration company are held liable for the decisions made, unless they have relied in good faith on,“…a written report of the auditor, or a report of a lawyer, accountant, engineer, appraiser, or other person whose profession lends credibility to a statement made by any such person” (OBCA, 1994)."

Jan 1, 2003

By J Hutchings

An essential component to the management of any process is the measurement of key parameters, used to monitor, control, and provide the feedback necessary for improvement. This paper discusses how data collection and analysis can provide a better understanding of the blasting process, as well as additional control and improved outcomes.The drill and blast process involves the generation and use of information at a number of levels. Comparison of historical parameters and results provides a starting point for the development of ongoing blast designs and a baseline against which future results can be compared. The collection of data during implementation provides a quality assurance/quality control (QA/QC) function where potential defects (such as under-drilled or over-charged holes) can be rectified prior to firing. Actual quantities and production rates allow the development of realistic plans and schedules, rather than using inaccurate estimates and targets that lead to unscheduled changes to equipment paths. Over?the past several years there have been a number of technological advances in data collection technology. Drill monitoring instrumentation on blasthole drills provides location information and feedback on rock properties as drilling occurs. Hand held ‘data logger’ technology has also overcome the challenges of working on the bench, such that blasthole measurements can be collected and forwarded directly to the explosive truck. Mine sites are becoming wireless network-enabled allowing the seamless data transfer from the field back to the office, in near real time, as that information is collected. Great strides have also been made in the development of drill and blast software systems which are more user friendly, and yet provide far greater capability to manage the quantity of data generated. The blasting process is critical to the overall mining process and the delivery of a successful blast outcome requires that the blasting process be ‘in control’. The measurement of key parameters can provide the data with which to measure and maintain control of blasting, and allows the validation of performance improvement measures and identification of improvement opportunities.

Nov 8, 2011

By Madan M. Singh

Section 516 of Public Law (PL) 95-87, commonly known as the Surface Mining Control and Reclamation Act of 1977 (SMCRA), requires that underground coal mine operators must "adopt measures consistent with known technology in order to prevent subsidence causing material damage to the extent technologically and economically feasible, maximize mine stability, and maintain the value and reasonable foreseeable use of such surface lands, except in those instances where the mining technology used requires planned subsidence in a predictable and controlled manner..." Implied in the constraints of Section 516(b)(1) of SMCRA is a determination of what constitutes "material damage" to surface structures, renewable resource lands, and the capacity for sequential land use following underground mining. The authors have already briefly addressed the subject of damage criteria in relation to surface structures (Bhattacharya et al, 1984). In this paper, an attempt is made to provide quantitative guidelines to ascertain material damage to renewable resource lands, although the data available to establish these criteria are considerably more limited than is the case for surface structures. Besides, many more variables influence the severity of the impact at a given site, making the task of assigning stringent ground movement limits even more complex. This often necessitated use of professional judgement and occasional reverting to a qualitative approach. Hence the reader is cautioned at the very outset that the quantitative limits presented herein are approximate and are primarily intended to serve as rough guides for ascertaining the extent of damage to the renewable resource lands under consideration, and that depending on site-specific conditions the actual damage incurred may differ significantly from that predicted by the proposed criteria. The authors, however, feel that the criteria suggested are somewhat conservative, but realistic. The actual damage observed should generally be less severe than predicted by these criteria. It may also be clarified here that the term "subsidence", as used in this paper, implies the total phenomenon of surface and subsurface effects associated with the mining of minerals and not only the vertical displacement of the surface as is sometimes inferred in the literature.

Jan 1, 1984

By Charles D. Haynes

Outside air for ventilating coal mines in Alabama varies considerably in both temperature and moisture content during the year. Alternate condensation and evaporation of the moisture on mine roofs may result in stresses detrimental to the strength of mine roof. It is well known that the clays in shales absorb moisture, and many investigations have noted the weakening of shales by absorption of moisture. Parker (1970) concluded that there is an annual cycle of rock deterioration in mine roof rock caused by the annual temperature-humidity cycle at the surface. He further noted that moisture reduces the strength of dry rock by one-half, that moisture added to dry rock can cause failure in compression, and that drying of wet rock causes tensile stress buildups by shrinkage. His recommendations for alleviating the moisture-temperature problem was to seal the rock in critical areas and to control ventilation so that air temperature will be lower than rock temperature. The latter recommendation will avoid condensation on the rock surfaces. Hartmann and Greenwald (1941) published the results of a very comprehensive experimental project to determine the effect of temperature and humidity changes on the behavior of mine roof. Their general conclusions included statements that roof rocks were very sensitive to moisture changes, but had low coefficients of thermal expansion. The coefficients were twice in the direction normal to the bedding plane as compared to the parallel

Jan 1, 1975

By D Preedy, J K. Claflin, S R. J La Brooy

This paper summarises the lessons learned during a recent carbon reactivation kiln upgrade project at the Sukari Gold Mine in Egypt. The kiln is being replaced to ensure that the plant achieves full value from the current throughput expansion from 5 to 10 Mt/a.The suitability of the original engineering design criteria for kiln selection and the adequacy of the original kiln are reviewed in the light of the carbon chemistry, operating experience and a site inspection of the kiln. Particular aspects of the reactivation facility are discussed including: predrying, preheating, feeding, gas seals, kiln heat transfer, steam injection, counter-current sweep gas flow, carbon cooling, fines minimisation and removal.Design criteria for a carbon predryer, reactivation kiln and cooler combination for carbon heavily fouled by high molecular weight frothers and collectors are discussed and the abridged Ausenco datasheet for the combination is presented.Responses to a request for a budget price sent to most of the worldÆs suppliers of carbon regeneration kilns are summarised.CITATION:Claflin, J K, La Brooy, S R J and Preedy, D, 2013. Ausenco carbon reactivation design criteria, in Proceedings World Gold 2013 , pp 401-410 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By S. J. Gerdemann

In support of its objective to improve mine safety, the Bureau of Mines has searched for better materials and systems to anchor roof bolts. TIlis report describes a study on the effects of mine waters upon accelerated gypsum, one of the materials under consideration. The accelerated gypsuw dissolved at an appreciable rate relative to an assumed 10-yr life span of a roof bolt. Surface orientation, initial ion concentration of a dissolving solution, and flow rate of the solu-tion had substantial effects on the dissolution rate. Factors such as water-cement ratio, accelerator content, wax capsule additions to the gypsum in cartridge-installed bolts, surface area, temperature, and curing duration had little effect. In an actual roof-bolt environment, dissolution will occur in static solutions to the solubility limit of gypsum (~2 giL) and cease, result-ing in minimal damage; but in flows of unsaturated solution as slow as 1 L per month, a loss of up to 10 pct will occur in 2 yr. Since miners cannot readily measure the flow or ion concentration of static-appearing water at every roof-bolt site, all such water must be assumed to be pure and flowing. It is recommended that gypsum-bonded roof bolts be confined to dry roofs only.

Jan 1, 1983

By P. Lussiez

Precipitates consisting of amorphous ferrihydrite and crystalline goethite have been prepared by aging hydrolyzed Fe (III) solutions at room temperature. The precipitates have been characterized by x-ray diffraction and differential thermal analysis. The amorphous ferrihydrite transforms to goethite with time. The ferrihydrite to goethite transformation is affected by the presence of small amounts of copper or nickel coprecipitated with the iron. .The addition of copper decreases the amount of goethite at a given aging time and increases the amount of coprecipitate which is initially dissolved in sulfuric acid, but it does not seem to affect the dissolution of the crystalline part'. It is proposed that adsorption of copper hydroxo species on goethite nuclei delays the ferrihydrite to goethite transformation. The effect of nickel is less dramatic than that of copper. Apparently a portion of the added nickel is adsorbed on the goethite crystallite surface rather than incorporated into the goethite lattice.

Jan 1, 1981

By T. I. Urbancic, C-I. Trifu

"ABSTRACTSeveral case studies are presented on the use of seismic techniques to map active structures, evaluate changes in stress levels, and identify the conditions leading to large magnitude seismic events and the generation of rock-bursts in Canadian mines. The results suggest that microseismicity can be used to identify the orientation of active fractures; define regions of relatively high and low stress, and those most likely to host a rockburst; determine the role of local stress on observed shear failures; and identify the path of stress transfer associated with the remote triggering of rockbursts. Additionally, the conditions leading to rock-bursts can be characterized by a significant increase in the clustering of microseismic events along the fault plane orientation of an impending event, and an increase in the effective stress levels. It is concluded that the analysis of microseismicity provides the means for remotely monitoring rock mass behaviour as a result of mining."

Jan 1, 1997

By K. Gao, R. Dry

"Carbon boil, which results in excessive spitting and even complete destruction of a metal drop, could significantly influence the efficiency of direct smelting processes. Carbon boil has been studied as a function of some key parameters such as melt sulfur content, oxygen partial pressure, and melt area/volume ratio. The time of carbon boil was determined using a CCO camera coupled with a time/date generator connected in parallel to a video recorder and a computer. The time of carbon boil was in the range ~5 - 15 seconds under the conditions in this study. A mechanism for carbon boil has been proposed.IntroductionThe occurrence of carbon boil in molten iron drops can result in excessive spitting and sometimes even complete destruction of a metal drop. In direct iron smelting processes, this could significantly influence the decarburisation of liquid metal and the post combustion and hence may influence the efficiency of smelting processes. The generation and consequent ejection of metal droplets into the gas phase occurs due to the intense turbulence in the bath which results from the injection of gases and coal. The aim of this investigation is to understand the fundamentals governing the carbon boil phenomenon under direct iron smelting conditions to assist control of process efficiency.Carbon boil phenomenon has been studied as a function of some key parameters such as melt sulfur content, oxygen partial pressure and melt area/volume ratio. The time for the occurrence of carbon boil has been determined in this study at 1440 °C using a novel approach which includes utilisation of a CCD camera coupled with a time/date generator connected in parallel to a video recorder and a computer. This arrangement permits the capture of the entire sequence of events leading up to carbon boil and therefore the determination of time of boil which is in the range -5 - 15 seconds under the conditions in this study."

Jan 1, 1996

By E. Naesgaard, Brian E. Hall, A. Amini, Advanced Geosolutions, A. Azizian

"A 2 km section of the Evergreen Line Rapid Transit Project is supported on improved ground consisting of cement deep soil mix (CDSM) panels because of highly variable and challenging soil conditions, especially the potential for seismic liquefaction-induced lateral spreading. CDSM was used as an alternative approach in place of driven piles for reducing the seismic lateral spreading displacements. An additional significant aspect of obtaining owner acceptance for CDSM was demonstrating that both seismic and non-seismic performance would equal or exceed that of using driven piles. It was recognized that, to demonstrate adherence to the seismic performance requirements, seismic design should be based on dynamic analyses (using FLAC) to estimate likely displacements and stresses/strains in the CDSM panels. One focus of the analyses was investigating the potential for cracking of the CDSM panels and the resulting displacements. This was simulated using the Ubiquitous-Joint and UBCSAND constitutive models.INTRODUCTIONThe Evergreen Line Rapid Transit Project (ELRT) is an 11 km extension of the SkyTrain system through Burnaby, Coquitlam and Port Moody in the Lower Mainland of British Columbia, Canada (Figure 1). The ELRT project is being delivered through a Design/Build/Finance model by Evergreen Rapid Transit Construction (EGRT), an SNC-Lavalin Inc. company, to the Province of British Columbia (the Province).This paper discusses the ground improvement design for a 2 km section of the alignment through Port Moody, a historic city at the head of Burrard Inlet. The alignment is located in a right-of-way of restricted width with many pinch points close to residential and commercial properties, and directly adjacent to the Canadian Pacific Railway (CPR) mainline tracks. The ground slopes from south to north across the alignment towards Burrard Inlet at inclinations of up to about 6%. Design and construction of the Port Moody section was subcontracted to SNC-Lavalin Constructors (Western) Inc. (SLCW) and SNCLavalin/ Graham Construction Joint Venture (SGJV). Construction included single- and double-track slab guideways, pocket track (where up to four to six tracks were present), and Moody Centre Station."

Jan 1, 2015

By F. Bello, J. Engels

"During 2012 and 2013, Minera Esperanza conducted a series of thickening and deposition trials to identify design and operational parameters associated with increased thickening of its tailings. These trials focused on benchmarking the current solids concentration of tailings (62 - 64%) in anticipation of an increase to 67% solids once two new 45 m diameter deep-cone paste thickeners are commissioned in 2014. These trials studied the sedimentation and rheological characteristics of the existing tailings and performed deposition modelling to assist with developing short- and long-term designs for the tailings storage facility. To verify and optimise these models, Minera Esperanza considered a series of laboratory, pilot, and industrial-scale deposition trials. This paper provides a review of the trials conducted in the laboratory and at industrial-scale and considers the results and optimisations for the short- and long-term design of Minera Esperanza’s tailings storage facility."

Jan 1, 2014

By E Beltran, S Ngunz, F Orrante, F van Zyl, M Westcott

"The primary control objective of the project is to achieve milling optimisation by ensuring that the energy available for rock breakage is used as efficiently as possible. This is achieved by increasing the level of mill filing until a process constraint is reached. Stable operation against this limiting constraint is then maintained to ensure long-term optimised operation.Semi-autogenous grinding (SAG) mill control optimisation presents a number of challenges. SAG mills have multiple inputs that are used to control multiple outputs (MIMO process). Secondly, the SAG mill loading process is a ‘high inertia’ process that can be approximated as an integrating process. This means that it is open-loop unstable. The hybrid control strategy presented implements an advanced ‘load stabiliser’, which transforms this integrator process into a more manageable first order process, which can be steered stably against the constraints. This SGS hybrid Expert control strategy implemented on both SAG mills at the Porgera concentrator therefore consists of two integrated parts responsible for:stabilising the mill load to a targetdriving the mill load target to the maximum determined by the process constraints (eg maximum power draw) to maximise efficiency and throughput. A comparative study is done between the operation of the plant for a period of a month before and a month after the implementation of this strategy. The results indicated a significant improvement in the SAG mills’ stability and operation as well as a reduction of overload situations leading to a loss of throughput.Citation:Ngunz, S, van Zyl, F, Orrante, F, Beltran, E, Westcott, M and Wilson, S, 2016. Simplified Hybrid Semi-autogenous Grinding Mill Control - Explanation and Practical Results at the Porgera Concentrator, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 313–320 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

The information age has arrived. In every aspect of life, at the end of the second millennium, computers and information technology have made significant inroads. In mining there has been huge growth in the use of digitally controlled systems. From resource evaluation to mine planning to daily operations, information is being acquired, analysed, modeled and presented, using state-of-the-art information technology. Explosives, too, have moved into the information age. Computer controlled trucks and manufacturing plants have been developed and are now a regular feature on many mine benches. The next challenge for the explosives industry as a whole is to integrate blast initiation with information technology. The benefits are there, both to the supplier and to the end-user. Much has been written in the past about the potential for blast improvement but there are other significant advantages to a digital initiation system. These include security from unauthorised use, stock control and minimisation, reliability through testability and ease of use to name a few. So why is it taking so long? Surely the complexity of an electronic initiation system is far less than that of mobile phones that have been around for a long time. The answer, it seems, lies in the level of new technologies that need to be developed. There are enormous technological hurdles to be overcome in order to put into the market a cost-effective, reliable, user-friendly electronic initiation system. The most significant of these are:Safely and reliably initiating an explosive from an electronic device powered by a small capacitor. Prior to the development of electronic detonators primary initiation of explosives was by shock tube spit or by passing large currents and voltages down a pair of wires. Electronic detonators do not have that luxury. For example the energy stored in a æBeethovenÆ exploder is more than 500 times greater than that available to an electronic detonator. Communicating to a multitude of devices over very long cables installed by miners in harsh conditions. The deployment of an electronic detonator system has been likened to building a large telephone exchange in the rain and getting it to work perfectly first time! New communications protocols needed to be developed and tested. Wiring and connection systems have to be designed to survive the mining environment. In spite of these technological hurdles most of the major explosives manufacturers have persisted with electronic initiation systems and we are now, in 1999, starting to see the results of these multi-million dollar efforts. At SMI we are often asked many questions about this technology. The remainder of this paper seeks to answer those most often asked. As with any business linked to information technology todayÆs breaking news is tomorrowÆs archive and we expect the rate of development and understanding to accelerate as these technologies become accepted by the global mining industry.

Jan 1, 1999

By Edward D. Thimons

Inflatable stoppings are currently marketed for production use, and numerous mining companies have become interested in using such stoppings in rescue and recovery operations. The Bureau of Mines therefore evaluated the concept of using inflatable stoppings in emergency situations. The stoppings tested by the Bureau were 12-foot-diameter spheres inflated with a blower operated by a small battery pack. Experiments were conducted with the stoppings in a full-scale wooden mine model to evaluate their ability to withstand sliding or slipping at various internal and differential pressures, puncture resistance, various inflation techniques; and internal leakage from the stoppings. The stoppings were then installed and tested in the Bureau's Safety Research Coal Mine at Bruceton, Pa., to determine their effectiveness as mine air barriers. Despite some encouraging results obtained with the model and in-mine studies, the stoppings did not perform well in two operating metal mines where they proved difficult to erect and inadequate as air barriers.

Jan 1, 1976

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