Search Documents

By Mark Ioli, Debra Struhsacker

In September 2004, Gale Norton, U.S. Secretary of the Interior, presented the Manhattan Mine with a U.S. Bureau of Land Management’s 2004 Hardrock Mineral Environmental Award. The Manhattan Mine is a sustainable development showcase. The reclamation accomplishments at this Nevada gold mine demonstrate how modern reclamation techniques can restore an old mining district into an aesthetically pleasing landscape that can support multiple and sustainable uses. In a collaborative effort that relied on substantial community involvement, Round Mountain Gold Corp.(RMGC) has improved the environment and eliminated a number of public hazards associated with old, unsafe mining features. RMGC’s community collaboration, innovative engineering, creative reclamation design and corporate commitment to environmental excellence show what Secretary Norton’s 4 Cs Initiative looks like on the ground and inaction.

Jan 1, 2005

Early in 1940 the development and sampling programmes in hand on the North and British Sections of North Broken Hill Limited were such as to necessitate the drilling of a large number of drill holes ranging up to about thirty feet in length. On the British Section, one purpose was to test the existence, width, and value of narrow lodes believed, for geological reasons, to occur in the walls of the existing workings. Another object was to definitely disprove the existence of payable shoots of ore in certain largerhodonite and quartz-garnet ("garnet sandstone") pillars which had been formerly left as unpayable.On the North Section, the main purpose of the short holes was to delineate the ore-body boundaries by drilling laterally from drives in ore, and thus enable level layout to be planned in advance of sill stoping. It was also desired to test the walls of stopes in those portions of the mine where the economic limit of mining is not rendered obvious by a clear-cut wall, but should be determined by assay. In these latter cases it was hoped to eliminate "prospecting by stoping," a procedure by which any doubts as to the existence of further good ore behind the low-grade walls were settled by continuing to stope laterally until all chance of such an occurrence was removed.LONG HOLE ROCK DRILLINGFollowing an investigation of recorded instances of similar practice elsewhere it was decided to use the rock drill for a series of trial sample holes. A 3-in. drifter was used. This was selected from those in use underground, and was given a special overhaul; had a new machine been purchased, a 4-in. type would probably have been obtained as being more suited to the work. The rods were H in. hollow round steel with a type "1" Jackrod thread. Couplings were of chrome steel, and were H in. in diameter, and 2 in. long. Jackbits (type "1" thread) in sizes from 2 in. to 4 in., with 1-in. gauge changes, gave a range of nine bit sizes. They were resharpened by hot milling, and were not milled to a definite gauge size.After sharpening, bits were sent underground without sorting into sizes, the drillers selecting the next bit with callipers. In view of the small scale of operations, it was not considered worth while to adopt special measures, such as the cold grinding of bits, which might have given a better product. Later, however, new bits were used exclusively, the idea being to accumulate enough blunt Jackbits to warrant a thorough treatment of the sharpening...

Jan 1, 1941

By D. C. Andersen, G. L. Smith, J. Pearson-Taylor

Following a restructuring of Anglo Platinum Limited in 2004 the strategic long-term planning function has been centralized. This paper describes the revised strategic long-term planning process covering aspects of the planning cycle, systems and methodologies, categorization of capital expenditure, corporate governance and planning tools.

Jan 1, 2006

By Keith A. Heasley, Lee W. Saperstein

This paper investigates the use of backfill zones and yielding pillars for subsidence control. The investigation begins by choosing an appropriate subsidence predictive technique to simulate the proposed subsidence-control schemes. Two case studies are performed in order to delineate the accuracy and utlility of the chosen predictive technique and then the results of these case studies are used to establish appropriate sets of regional site parameters. Next, a detailed analysis of the major variables affecting the outcome of the subsidence-control simulations is conducted and graphical displays of the exact sensitivity of the surface subsidence to these variables are given. Finally, alterations to the surface subsidence that are expected from using two major subsidence-control techniques are presented. The first technique to be assessed is a backfilled pillar centered longitudinally in a panel. With this arrangement, a minimal amount of backfill material can produce substantial decreases in vertical displacements. The second technique to be assessed is the use of yielding gate pillars to reduce the sinuosity of the transverse subsidence over adjacent panels. With proper design, this technique can greatly curtail surface strains and help minimize remedial drainage control.

Jan 1, 1986

William Frederick McBryde Broun, a graduate of the Royal School of Mines, was employed on the staff of the Mount Morgan Gold Mining Company for some years prior to 1912, and will perhaps be remembered by some of those who attended the Mount Morgan meeting of the Institute in 1910, as an Associate Member present on that occasion. He severed his connection with the Mount Morgan Company in 1912, and was returning to England via the East Indies, when he contracted typhoid atSingapore and died at Colombo.Years later some old papers were being turned out in the office where he had worked, when a set of M.S. notes in his unmistakeable handwriting came to light. On examination these appeared to be the rough draft of a paper he must have beenpreparing for the local branch of the Institute, which he had not been able to complete. The notes were very rough. Apparently it was the author's intention to fill in numerous gaps with extracts from sundry published articles on Cornish mining; theextracts were missing and only the written portions linking them together were there. They give a sketch of Cornish mining practice which those who wish may supplement (as the author would have done) from Le Neve Foster and other well-knownsources. The fragmental notes which have been pieced together as carefully as possible by Mr B G Patterson, Hon Secretary Mount Morgan Branch; are as follows :-The first mine the author worked at was Carn Brea, in 1904."This is one of the largest tin mines in Cornwall, and belongs to the Carn Brea and Tincroft Mining Co, which also owns Cooks Kitchen. The mine was started in 1832, but had been in a bad way for several years previously, and had just begun to recover...

Jan 1, 1919

By P Fullagar

Automated multi-sensor core loggers (MSCL) measure petrophysical properties of diamond drill cores, including gamma density, P-wave velocity, electrical conductivity and magnetic susceptibility. A Geotek MSCL system has been used to record petrophysical data on archival drill core from Cadia East Au-Cu porphyry deposit, New South Wales, Australia, for correlation with metallurgical parameters. P-wave modulus, calculated from density and P-wave velocity, exhibits a correlation with small-scale crushability (A*b) test results, and hence offers a means for æcontinuousÆ characterisation of ore crushability at Cadia East. Magnetic susceptibility has proved to be a good indicator of alteration styles, and is a possible indicator of crushability.

Jan 1, 2009

In recent years it has been more and more recognised that applied geology can be of service to the mining industry, and many mining companies overseas now have permanent geological staff as part of the operating organisation.Most of these companies insist that the geological department must pay for itself by the savings it can make in operating cost, and the growing use of the geologist is proof that such savings are made.The geological problems in every district are different, and a description of the problems and method of attack in a specified district is a useful addition to the literature of mining geology. Very few contributions, from the standpoint of the mining company geologist, have appeared in the Australian literature so that, although the operations of Bendigo Mines Limited are still in the development stage, and its geological work newly established, a description of the routine geological work at Bendigo should beof interest.Although most Bendigo mining companies have not employed permanent geologists, they have utilised geological guidance wherever possible, and a great body of data has grown up. Acknowledgment is made here to the valuable work of the Geological Survey of Victoria, especially the writings of E. J. Dunn, H. Herman, and H. S. Whitelaw, and the maps of Caleb Thomas and H. S. Whitelaw; and also to the work of independent investigators, notably Chief Geologist, Bendigo Mines Ltd.

Jan 1, 1936

By Rosana Silva Xavier

Compósitos magneto-elétricos (ME) combinam fases magnetostrictivas e piezoelétricas e podem ser utilizados na geração de energia a partir de vibrações e campos magnéticos presentes no ambiente, sendo também aplicáveis em sensores de campo magnético e em redes de sensores sem fio. Neste trabalho, um compósito ME foi processado pelo método cerâmico com 15 vol% CoFe2O4 (ferrita de cobalto) como fase magnetostrictiva e 85 vol% BaTiO3 como fase piezoelétrica. É mostrada a relação entre os parâmetros de processamento/sinterização e a microestrutura do compósito ME, com três tipos diferentes de arranjo das fases: particulado (obtido por dois diferentes métodos) e em camadas. Foram compactadas pastilhas dos compósitos para sinterização nas temperaturas de 1.200ºC, 1.300ºC e 1.400ºC por 4h, sendo que ocorreu a fusão da pastilha sinterizada a 1.400ºC. As amostras sinterizadas foram observadas em microscópio eletrônico de varredura (MEV), onde foram analisadas as características de porosidade, tamanho de grão e a distribuição das fases na microestrutura. Foram realizadas também análises cristalográficas por difração de raios-X (DRX), de espectroscopia RAMAN e de espectroscopia de energia dispersiva (EDS). Foram relacionados os parâmetros de processamento utilizados com os resultados obtidos.

Aug 8, 2018

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

NASA has received direction for lunar habitation beginning in 2024. Prior to then, it will be necessary to learn about how lunar soil can be used to promote civilization on the moon. Questions must be answered: ?Will it support plant life?,? ?Can it be used as a construction material?,? ?What is needed to maximize health and safety?,? and ?Will it affect equipment, tools, machinery, and clothes?? The only samples available for study came from the Apollo Missions. Because the expense of bringing more material back to Earth is prohibitive, there is not enough available to perform studies to answer the above questions. Hence, there is a great need for its synthesis. Most efforts to date have concentrated on making ?simulant? from single natural resources of volcanic rock. However, another possibility is to use resources here on Earth to extract the minerals of interest into concentrates or so-called ?separates? using traditional mineral processing techniques, and then mix the separates in appropriate ratios to simulate the lunar soil. In this paper, results from a study in which dry Road Norite outcrop and wet mill tailings from the Stillwater Mining Company?s Concentrator located near Nye, MT were examined. Of course, the in-side challenge is to make ?separates? from gangue minerals.

Jan 1, 2012

Triboelectric Charge and Separation Characteristics of Industrial Minerals The basic principles of triboelectric charge and separation of minerals and the factors affecting the entity of the charges developed on mineral surfaces are discussed and the surface pretreatment methods by which the electrophysical properties and thereby triboelectric charging and separation of minerals can be artificially altered/modified are reviewed. Furthermore, the triboelectricfication theory of materials is envisaged from the chemical concept of acid-base donor-acceptor and an attempt is made to correlate the physical concept of triboelectrification with the donor-acceptor properties. The triboelectric charge characteristics of the quartz, calcite and wollastonite mineral samples for different size classes were defined using different tribocharging medium. Based on the triboelectric charges acquired by mineral samples their energetic work function values are estimated. In addition, the main electrophysical properties, ie dielectric constant and electrical conductivity, of different size fractions of the mineral samples are measured and their donor-acceptor chemical properties were defined. A series of triboelectric separation tests were conducted to explore the possibilities for separation these mineral from each others. The results from the triboelectric charge and separation of the single mineral systems showed promising prospect in separating quartz, calcite, and wollastonite from each others. Finally, attempts were made to explore the possibilities to implement triboelectric charge and separation process to real ores. Promising results achieved when separation of calcite from silicate impurity was sought from a carbonate ore. A very high purity (99 per cent) calcite product was obtained at a recovery of 80 per cent. Interesting results were also achieved to concentrate wollastonite from a complex silicate ore containing quartz, different feldspars, wollastonite and other Mg-Fe silicates. In this case conditioning of the ore with salicylic acid at defined temperature and relative humidity was found to be essential to concentrate wollastonite. The outcomes indicate despite the fact that triboelectric charge and separation process has not been completely perceived, it pronounced to be an environmentally friendly and economically viable technique for minerals and wastes beneficiation. Being a dry beneficiation technique the process has special appeal, which must be explored further in particular for treating industrial minerals.

Sep 13, 2010

By Michael J. Sapko, William D. Monaghan, Michael A. Trevits

Mine seals are used extensively in underground coal mines to segregate mined-out areas and to isolate fire zones or underground areas that are susceptible to spontaneous combustion. Over the years, 30,000 mine seals have been erected in underground coal mines in the United States. Mine seals, along with rock dusting and ventilation, represent the fundamental means of preventing underground coal mine explosions. In this study the National Institute for Occupational Safety and Health (NIOSH) used ground penetrating radar (GPR) technology to determine if each of three test mine seals were uniformly constructed. Three mine seals representing different construction methods and materials (cast-in-place foamed cement; solid block, polyurethane foam and gravel; and wire mesh, rebar and gunite) were erected at the NIOSH Lake Lynn Laboratory’s underground mine as part of an on-going research program. The seals were imaged using GPR with 400-, 500-, 900-, and 1,000-MHz antennas. We found that variations in uniformity existed in the material for the cast-in-place foamed cement seal. Variations in uniformity also existed in the seal made from solid block, polyurethane foam and gravel. The post-processed radar records correlated closely with recovered core samples (areas of gravel and polyurethane foam, and areas containing only polyurethane foam). Finally, the radar records of the seal made of wire mesh, rebar and gunite showed the various components. The results of this work suggest that GPR could be used as a tool to evaluate mine seal characteristics and construction uniformity.

By Silver EA

The Finisterre Range on the north coast of Papua New Guinea is the uplifted forearc riagio.n. of a modern arc-continent collision. The core of the range is composed of the P- nisterre Volcanics, an Oligocene''-arc terrane. The southern flank of the range consists of a clastic sedimentary sequence which is an uplifted accretionary wedge and collision complex. This clastic sequence can be subdivided into three distinct units. To the south of aiid structurally below the Finisterre Valcanics are the Mebu beds, an Oligocene- $arly Miocene sequence of volcanolithic turbidites. The Erap Structural Complex is south of, and structurally below the Mebu 43eds. , It consists of three subunits; the 3rly Pliocene micaceous turbidites of the Sukurum unit, contemporaneous pillow basalts AF{ the Basalt unit, and Late Pliocene to Pleistocene volcanolithic turbidites of the -Nariawang unit. The Quaternary Leron Formation, a fluvial to shallow marine 'clastic unit, is the southernmdst. and structurally lowest unit of the clastic -sequence The Finisterre Range is dominated by a fold-and-thrust belt with most thrusts "dipping steeply N. Melange fabric _ is developed in the vicinity of major thrusts. "ffle thrust belt strikes NW, oblique to the regional convergence direction, but no strike-slip motion is observed along NW striking faults.

Jan 1, 1991

Concentrations of bright green material in the "Golden Mile" of Kalgoorlie, which carry particularly high gold values, are known locally as "green leader".This assemblage consists largely of quartz, sericitic muscovite, carbonates, and pyrite. Some of the sericitic muscovite contains vanadium, giving the rock its green colour. Vanadium oxides, including nolanite, are also present. Tellurides identified in this study are calaverite, altaite, petzite, melonite, and coloradoite. Native gold was found in most of the samples; some of the gold, at least, has been formed from the decomposition of gold tellurides.It is suggested that mineralizing solutions carrying gold and tellurium leached vanadium from the host rocks and subsequently deposited gold tellurides and vanadium-bearing minerals in the "green leader".

Jan 1, 1977

Traditionally, capital costs of major resource development projects have been estimated as a single amount to which a percentage accuracy has been assigned based on the method of preparation of the estimate, that is, on the amount of information available to develop the estimate.However, there is a growing recognition of the importance of a probabilistic approach to capital cost estimates, and of a more rigorous calculation of estimate accuracies and of the presentation thereof. Accuracies can be expressed with more certainty as a percentage of the estimate amount where the percentage represents one standard distribution on the probability curve for the capital cost of that specific project. Thus confidence levels can be stated for various estimated amounts - for example, it can be stated that there is an 85% chance that a stated amount will not be exceeded, or a 90% certainty that a (higher) amount will not be exceeded. Moreover, the right skewness of the probability distribution curve for most projects can be readily recognised and reflected in the evaluations. This enables senior executives and board members to have a clearer understanding of investment uncertainties, and the possible magnitude of commitments.

Jan 1, 1990

Perhaps one of the most important conferences or symposia which our Institute has conducted, was the joint Aus. LM.M./AJ.M.E. meeting held in Canberra in May 1978, with the theme International Resource Management (Woodcock, 1978).We were privileged to witness active participation in the meeting by outstanding personalities from the mining and metallurgical industries of Australia and New Zealand, the United States of America, Canada and the United Kingdom and to hear addresses on subjects of international significance to the mining and metallurgical industries.Our Institute is one concerned with professionalism.The principal objects of The Institute as described by our founders include, "promoting the arts and sciences connected with the economical production of the useful minerals and metals, and the welfare of those in the industries, by meetings for social intercourse, and the reading and discussion of professional papers, and to circulate by means of publications amongst its members and associates, the information thus obtained".Sir Maurice Mawby (1968) said in his Presidential Address to the Institite, "the most important aspect of these objects was the promotion of the arts and sciences of the mining industry".Why is it then, that a large proportion of the papers given at the meeting in Canberra dealt with world wide social aspects of the mining and metallurgical industries, rather than the technology, the arts and sciences of mining and metallurgy as principal factors in international resource management?The answer is quite simple of course, and that is that the social and political factors are the principal factors which create the demand for basic raw materials and in the long term determine the costs and prices of the commodities which our professional abilities are drawn upon to produce.

Jan 1, 1979

By P. H. Derbyshire

The use of continuous flight auger piles has increased significantly in the U.K. to such an extent that it is now the most widely used method of constructing small diameter bored piles. This paper describes the improvements in equipment, techniques and particularly monitoring that have led to this growth. A review of the equipment in use describes how purpose built self erecting machines have been generally adopted. Improvements in ancilliary equipment are described. Concrete has almost completely replaced grout and techniques have been developed to extend the length of reinforcement that can be placed. Leading specialist contractors have developed instrumentation to monitor the construction of the pile (in terms of time, depth, torque, concrete pressure and flow) and keep a record for checking. A further significant development of this monitoring by means of sensors at various levels in the auger stem is described. The results obtained from this monitoring are reviewed and future developments discussed.

Jan 1, 1989

By P González, J Videla, E Córdova, I Gottreux

Currently, underground mining of deeper massive deposits with lower grades, harder rock conditions in high strength environments, entails difficulties in caving, fragmentation and seismicity of the orebody.So far, the use of preconditioning (PC) with hydraulic fracturing (HF) has shown positive results in terms of seismic response and caving performance, while PC combined with explosives aims to weaken the rock mass, causing an additional effect on fragmentation.In particular, mines commonly referred to as ‘supercaves’, operated by caving methods, have the need to integrate mine to plant processes, where rock fragmentation appears as a key tool. In fact, it implies making mining and comminution processes more efficient to the plant and for mines, it justifies the search of innovative solutions in drilling and blasting techniques to precondition the rock mass. The following paper aims to show the feasibility of numerical blast modelling to weaken the rock mass using explosives, mainly through sensitivity analysis applied to designs to minimise bias and uncertainty in the results. It is shown how the presence of structures, their geometry and in situ stresses influence or interfere with the PC method being used.From the work, it is concluded that better knowledge on the application of explosives weakening allows specialists to strengthen numerical models associated with every design and therefore previously validate their applicability, helping to understand complex phenomena such as the propagation of mechanical waves in non-elastic heterogeneous media. In this sense, it is understood that while there are studies (Sanchidrián, Segarra and López, 2006) showing that the transfer of energy in the rock mass could be even greater in a confined environment, the more competent rock mass and higher in situ stresses interfere mostly on the effectiveness of a technique using explosives.CITATION:Gottreux, I, Córdova, E, González, P and Videla, J, 2016. Preconditioning modelling and explosives effectiveness in block caving, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 683–688 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By H. F. Coward, G. W. Jones

"IntroductionIn the course of an investigation on the influence of black damp (a mix of nitrogen and carbon dioxide) on the limits of inflammability of fire damp (methane) in air, some new information was obtained concerning the factors that determine whether or not a gas mixture is capable of self-propagation of flame. Volume for volume, carbon dioxide exceeds nitrogen in its extinctive action on flame, an effect which is generally attributed to the higher molecular heat capacity of the former. Argon, a as of lesser heat capacity than either, proved to Lave less extinctive notion. If, as seemed likely, the extinctive action of a chemically inert gas could be attributed entirely to its heat capacity, then helium should behave like argon; equal volumes of these two oases should exhibit equal extinctive action, for their molecular heat capacities are nearly identical at laboratory temperatures and, in all probability, remain constant up to and beyond flame temperatures. The experiments reported here show, however, that helium has proved to be more extinctive of methane flames than argon.Method Used in ExperimentsThe limits of inflammability of methane, in various ""atmospheres"" composed of mixture of air with one or other of the diluent were determined in a vertical glass tube, 6 feet long and 2 inches in diameter. The lower end of the tube was opened by sliding away a ground-glass joint and the flame of a small spirit lamp was immediately passed across the aperture. The tube was sufficiently long to enable observers to judge whether a flame was self-propagation for if a mixture were incapable of continued self-propagation pf flame, the lamp of flame formel above the source of ignition was extinguished within feet of its passage up the tube."

Jun 1, 1926

Laboratory electrical resistivity measurements of rocks are reviewed. Inductive and galvanic methods are discussed together with the ten important experimental factors which should be considered in an investigation.These experimental factors are electrodes, sample preparation, measurement errors, temporal current variations, current density, frequency, electrolyte composition, electrolyte saturation, pressure, and temperature.

Jan 1, 1969