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By H. Verakis, M. J. Sapko

The Pittsburgh Research Laboratory (PRL)1 of the National Institute for Occupational Safety and Health (NIOSH) in collaboration with the Mine Safety and Health Administration (MSHA) Technical Support Center has devised a prototype hand-held instrument which can provide a direct assessment of the potential explosibility of a coal and rock dust mixture. Current Federal regulations require that rock dust be applied in all underground areas of a coal mine to mitigate the propagation of a coal dust explosion. To determine compliance with the Federal regulation, mine inspectors collect dust samples from sections of underground coal mines for an MSHA laboratory analysis of incombustible content. However, the laboratory analysis may not be completed for more than a week or two, during which time the mine area from which samples are taken may be inadequately protected. The operation of the Coal Dust Explosibility Meter (CDEM) is based on the difference in optical reflectance between light rock dust and dark coal dust. For a given coal volatility, the optical reflectance of such mixtures is relatively constant at the limit of explosibility, independent of the coal dust particle size. The CDEM is not intended to replace the current MSHA laboratory analysis of coal mine dust samples for incombustible content, but to serve as a supplemental device for enhancing mine safety through improved rock dusting practices.

Jan 1, 2006

Fast Adsorption Phenomena at Air/Liquid Interfaces

Sep 13, 2010

By David Allen

Cable bolting is a relatively new strata reinforcement technique that has been used successfully in Australia and the United Kingdom. Jim Walter Resources, Inc. has examined the principles and can visualize its useful application in many areas, such as: a) Longwall pull-out areas, b) Roadway junctions, particularly those involving yield pillars, c) Rib reinforcement, and d) Possible replacement of cribbing in roadways, especially longwall tailgates. This paper describes the conditions which led to cable bolt testing, the results of tests conducted to date, and conclusions about the direction that Jim Walter Resources, Inc. is heading as far as testing and potential applications are concerned.

Jan 1, 1994

By Andrew P. Jarosz

The present computerized mine planning systems use CAD-like and Data Base Management System (DBMS) environments for the handling of numerical, textural, and graphical data. These two environments are usually integrated, that the data provided by the DBMS are linked to any graphical element rendered by the CAD system. The subsidence monitoring, analysis and prediction process should be integrated with the mine design process. It should allow for the assessment of impacts of mining on surface, surface utilities, and structures. It should also provide for the measures to control mining, that will create only acceptable levels of negative impacts on the surface. The common data base, and graphical capabilities of the CAD interface, may be used with great advantage for both systems. The findings of the subsidence engineering modulus should be directly incorporated into the mine design system, and vice versa. In this paper the author suggests guidelines for the development of the comprehensive computer system, able not only to predict the vertical and horizontal components of the ground movement, but also assess the induced surface damages, and costs related to subsidence prevention and compensation.

Jan 1, 1995

By William H. Snyer

A relatively inexpensive, very fast response photo-optic/fiberoptic system has been conceived, constructed and employed by Denver Research Institute (DRI) to measure charge breakout uniformity on the surface of a very large ANFO detonation. The new equipment and technique was coined OWL (observation without leads). Its unique design provides the ability to monitor or measure detonation velocities and/or detonation breakout characteristics without fiberoptic or any other direct contact with the explosive. This system has proven to be versatile and has been used to measure surface breakout simultaneity on large ANFO detonations, munition case breakout times and velocity of detonation (VOD).

Jan 1, 1990

By N H. Jansen, H L. Bridgwater

Field portable X-ray fluorescence (XRF) and near infrared (NIR) instruments are proven technologies in the minerals industry. The in-field results of these instruments can add value early in the project life, leading to cost-effective decision-making compared to their equivalent laboratory based techniques. However, in order to add value to a project, it is crucial that the instruments are employed correctly.Orientation studies should be carried out prior to initiating a sampling program to achieve the highest level of quality assurance and control for the results. Hence, an appropriate sampling workflow begins with considering what outcomes are required, including level of precision, accuracy, reliability for elements and minerals of interest, and sampling errors. The workflows proposed include soil sampling and reverse circulation and diamond drilling sampling techniques, and laboratory based techniques. They are practical and flexible workflows using available portable XRF and NIR technologies that can be applied to current sampling and drilling methods.The combined technologies have the ability to create large, integrated geochemical and mineralogical data sets that can provide cost savings for every stage of the mining chain from exploration to prefeasibility, mineral processing and environmental remediation.CITATION:Jansen, N H and Bridgwater, H L, 2017. Proposed workflows for portable X-ray fluorescence and near infrared instruments for soil and drill hole sampling, in Proceedings Eighth World Conference on Sampling and Blending , pp 219–228 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

LANDSAT imagery has renewed interest in linear features first recognised by E. S. Hills in a physiographic model of Australia. Certain of these lineaments are aligned with structures which control mineralisation.Lineament guidelines are potentially useful in many poorlyexposed areas if they can be recognised early enough in exploration and drilling programs leading to mine development.A case history based on the Charters Towers Gold Field indicates that lineament guidelines can be established early enough to guide development ofnew mines. The position of the Charters Towers Lineament was known as early as 1956. Subsequently, more detailed publications identified and classified associated lineaments which provide intersections correlated with gold occurrences. The discovery of a significant orebody at one of the most prominent lineament intersections came in 1975. Mine drilling has confirmed the influence ofintersecting structural trends indicated by lineaments but not by previous regional mapping.Recent gold discoveries south of Charters Towers lie in a grid of prominent lineaments. The development of mines about Charters Towers will provide additional understanding of relationships between centres of mineralisation and lineament intersections. This understanding may in future be sufficient to encourage exploration for a new generation of concealed gold deposits in northeastern Queensland.

Jan 1, 1986

By José A. Rios, José A. Vidalôn

The case study of a highland area in the Central Andes of Peru, where many abandoned polymetallic mines are found, is presented. Some of these mines generate metal leaching and acid rock drainage (ML/ARD) or have potentially ARD generating (PAG) tailings/waste rock storage. Effluents are discharged into the first of two lakes in line, which act as reservoirs for irrigating an important valley in the desert coastal region. Drainage fees, their relationship with the deposit and the solid-wastes mineralogy are discussed, as well as variations in water and sediments composition, the benthos, and the aquatic/riparian flora/fauna in these lakes.

Jan 1, 2000

By J S-L Chan, J C. T Chu

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. In its industrial days, Hong Kong’s mining industry was thriving, benefitting from the mineral occurrences that are related to the regional Mesozoic igneous and hydrothermal activities.Hong Kong was unique in the mining sector as it was so small in landmass but with such a rich variety of commodities discovered. There are records of commercial exploitation of tungsten, iron, lead, silver, beryl, graphite, quartz, feldspar and kaolin in Hong Kong before 1981. Of these, most of them are located in the New Territories.The Lin Ma Hang lead mine was operated in the 19th century by the Portuguese and was abandoned in 1958. The Needle Hill tungsten deposit was discovered in 1935 during construction of the Jubilee Reservoir. The Ma On Shan iron mine, which operated for 70 years between 1906 and 1976, was the largest mine in the history of Hong Kong. The Mui Wo lead-silver mine on Lantau Island can be traced back to the Ming Dynasty 400 years ago. West Brother Island, which extracted graphite from 1952 to 1973, was levelled in the 1990s to make way for the development of the airport at Chek Lap Kok.Nowadays, these mines are disused and abandoned, but this extended abstract reviews the legacy of the mining industry in Hong Kong to understand the impact that it had on techniques, the economy and culture.CITATION:Chu, J C T and Chan, J S-L, 2015. The history of mining in Hong Kong , in Proceedings PACRIM 2015 Congress, pp 109–114 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By S. L. Windes

"INTRODUCTION For a number of years, the Bureau of Mines conducted tests on various types of structures to ascertain the effect of seismic vibrations emanating from quarry blasting in an effort to determine an index of damage. Associat¬ed with these tests, occasional records were made of the characteristics of the air blast or concussion from the explosions. Although the importance of the air-blast problem was recognized, the equipment was not designed for airblast measurements, nor was the early research program concerned with the problem. After the ground-vibration tests had been completed, attention was turned to study of the air blast and its effect. The program was modified, however, in certain aspects by the imminence of war and the final entry of the United States into the conflict. These modifications were made to supply information pertaining to military and civilian defense problems.Detailed discussion of these problems is beyond the scope of this report, which attempts to present preliminary results of factual and fundamental character. However, it may be noted that airblast data are urgently needed for intelligent design of both Government and non-Government buildings, which must withstand the air blast from bombs and afford maximum protection for the occupants. The safety of vital equipment above and below ground necessitates consideration of damage from air blast. Protection against use of dynamite by saboteurs, moreover, hinges largely on the effect of air blast. Identification of a planned ""accident"" involving dynamite often entails knowledge of the characteristics and power of the airblast.The peacetime problem of damage from air blast resulting from quarry and mining blasting activities is of course exaggerated by the wartime requirements of increased production accelerated operation, and enlarged development."

Jun 1, 1943

By G J. Lyman

In sampling a process stream, conventional sampling theory deals only with the variation of the analyte content and neglects the impact of the variation in the mass flow on the sampling variance, whether the sampling regime is time-based or mass-based. This is an obvious simplification of the real state of affairs and it is worthwhile to study this impact via simulation.With a facility to simulate large (long) random functions having some thousands of points in the function and the ability to impose covariance functions on the mass flow and analyte variations, such a study is possible. It is also possible to evaluate the impact of correlation between analyte content and mass flows.This paper describes a limited study of the variance increase due to mass flow fluctuations over the usual sampling variance due to analyte variation during the sampling period. The bias in the sampling result is determined for specific modes of correlation. Simulation methods are used as they are the only means by which a sampling result can be compared to the true assay for the lot; in the physical circumstances of mineral process analysis, it is never possible to determine the true process stream assay.CITATION:Lyman, G J, 2017. The impact of the weighting error, in Proceedings Eighth World Conference on Sampling and Blending , pp 311–318 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By P. J. Remington

Field measurements utilizing a seat pad accelerometer were made on 25 underground coal mining machines in order to quantify the vibration levels experienced by the operators. Those data were combined with information on the statistics of the operating times of those machines in order to compare the operator's vibration exposure to the criteria in ISO 2631, "A Guide for the Evaluation of Human Exposure to Whole Body vibration." The comparison showed that about 30% to 40" of all underground coal mining machine operators can be expected to be exposed to vibration exceeding the fatigue decreased proficiency criterion, whereas only 10 to 15% would be expected to experience vibration exceeding the exposure limit. The primary sources of the exposure are shuttle cars and possibly scoop trams. Detailed exposure statistics are presented and the implications of the results are discussed.

Jan 1, 1983

By J. Wills

The use of drilling rigs to increasingly mechanize stope drilling has been acknowledged as important for the S.A. mining industry in it ís efforts to tackle the challenges of low productivity, AIDS and an ageing driller workforce. The spin-offs of increased safety, cost-effectiveness and better mining performance provide advantages to all?from the driller to the shareholder. However, implementation or product rollout has varied from outright success to dismal failure. A study of various cases by Novatek and Anglogold TDS showed clear reasons for these differences. Whereas the successes were characterized by clear objectives, accountability, user buy-in, a commitment to make the technology work and no-nonsense reporting, these were typically absent in failed implementations. The attitude at unsuccessful mines was to ?trial? the equipment?even subconsciously, a ?trial? is a test where failure becomes an acceptable outcome. During the study it became clear that mining management are not adequately trained to manage the often-tricky rollout process. They are often also not empowered or clearly mandated to deal with the organizational, human and technical issues that must dovetail to create a success. The output of the study was to develop a basic rollout process that could be used to formally manage the implementation of new drilling technology. Creating an alignment between the mine, workforce and supplier promotes a win-win situation that will not otherwise spontaneously arise.

Jan 1, 2002

By H. C. Seeber

When considering all the aspects of a viable mine plan, it is important to estimate the accurate cost of mine ventilation, which varies as a function of airway dimensions, fan selection and ventilation network. Optimization of the overall elements of ventilation design can lead to very significant cost savings when capital and operating cost savings are considered in combination. This paper will describe a methodology, whereby ventilation costs can be minimized by optimizing the ventilation aspects of mine design and fan selection, by providing a brief description on ventilation theory and the factors which affect ventilation operating and capital costs.

Jan 1, 2002

Fire-clay blocks lining the combustion chambers of zinc concentrate flash-roasting, furnaces operating at 1,000-1,200° C. have suffered moderately rapid deterioration due to slagging. The attack is accentuated by high temperatures, and is probably caused by lead oxide volatilized from the roasted concentrate.Resistance of refractories to attack increased with increasing alumina content from 30 to 45 per. cent but at 90 per cent alumina spalling was troublesome. Magnesite bricks were'subject to some spalling, but some types may lie satisfactory. Chrome and chrome-magnesite bricks spalled seriously.Material thought to be suitable for use as a monolithic lining slagged badly and an alternative may be tested.INTRODUCTIONThe Electrolytic Zinc Company of Australasia Ltd. uses two multi-hearth furnaces and four flash or suspension roasting furnaces for the roasting .of zinc concentrates at its Risdon Works. The hearth roasting plant has been described previously by Forster (1949).A brief descriptioI1 of the first three flash roasters was given by Gordon and Forster (1955). A fourth flash roasting furnace began operation early in 1957. This furnace is somewhat larger than the earlier furnaces, and the designed capacity is also higher, auxiliary equipment being altered to suit. An important structural difference between the older furnaces and the fourth flash roaster is that the walls of the combustion chamber of the new furnace are lined with high alumina fire-bricks instead of fire-clay blocks. Thischange was made because the fire-clay blocks in the older flash roasters had shown s-evere wastage due to slagging by lead derived from the concentrate.

Jan 1, 1959

By R. G. Peluso

Methods and results of studies to determine friction and shock losses encountered in auxiliary face ventilation systems utilizing flexible, spiral-reinforced ventilation tubing are presented. The results, tabulated in graphic form, simplify fan selection and enable mine operators to design adequate auxiliary ventilation systems. Problem illustrates the use of graphs.

Jan 1, 1968

By T. J. Ballard

"INTRODUCTION The Buck. Creek corundum area of Clay County, North Carolina, includes one of the largest single masses of peridotite outcrops in the whole Appalachian Range and has been described by Pratt, an early authority on corundum, as offering one of the best potentialities for corundum production in North Carolina.Two principal types of corundum deposits are found at Buck Creek the vein type and the corundum-bearing amphibolite dikes.The vein deposits occur in structural fissures that strike north to northeast in a gangue of feldspar, zoisite, an, chlorite. The corundum is generally coarse-grained and good-quality. The corundum content varies from several percent to 50 percent.The corundum in the amphibolites is more or less disseminated through the dike, is generally lower-grade, and is less in quantity, than the vein corundum. About 50 percent of the amphibolite corundum is coarse enough for snagging-wheel grade but is difficult to separate from the amphibolite.Production from the Buck Creek area has been small and came mainly from high-grade pocket in the vein deposits. Pratt 3/ reports 300 tons of corundum ore was produced to about 1896. No record of subsequent production is available.The critical shortage of corundum during the war, due to transportation difficulties and the depletion of deposits abroad, prompted the Bureau of Mines to investigate domestic reserves.After a favorable report was obtained on the Buck Creek area, the Bureau began exploration of the deposit in September 1943 and continued until February 1945."

Apr 1, 1947

By F. M. L. Mulaudzi

Metal dusting is a corrosion phenomenon that occurs in strongly carburizing gas atmospheres at elevated temperatures. Reaction kinetics and product characterizations of Alloys 602CA and 800 were examined by scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) and X-ray diffraction (XRD).The results showed that Alloy 602CA is more resistant to metal dusting than Alloy 800. Visual examination and SEM surface analysis showed that Alloy 800 suffered metal dusting attack after a relatively short exposure period. The amount of coke deposits increased on Alloy 800 with increased exposure from 96 to 336 hours. X-ray diffraction on the reacted surfaces identified graphite and austenite in both alloys and some iron oxides/spinel for Alloy 800.

Jan 1, 2012

By Sam Kangwa, Thomson Sinkala

Th e re are three basic types of hole deviations in long hole d ri l l i n g , n a m e l y collar i n g , alignment and tr a j e c t o r y dev i a t i o n s . In mining, the accur a cy in drilling has a significant effect on the effi c a c y and economy of mining oper a t i o n s . This ar t i cl e d e s c ribes the types, s o u r ces and effects of hole deviations in mining oper a t i o n s . The art i cle further demonstrates the economic consequences due to hole dev i a t i o n s .

Jan 1, 2004

By William M. Hinton

This report describes the approach, procedures, and results of a program to develop training materials for roof bolter operators. The objective of the program was to design and produce a training sequence which would prepare roof bolter trainees for job performance. Data was collected and analyzed using the general procedures of Instructional Systems Development (ISD). Input data came from a previous roof bolter training analysis program. This data was expanded and structured through a series of ISD steps: objectives hierarchies, media selection, syllabus, lesson specifications, and train¬ing materials development. The resulting program consisted of an ordered sequence of 15 lessons. The media mix for the 15 lessons included lectures, slide-tape lessons, and hands-on instruction using operational roof bolters. Contents of all lessons were reviewed and approved by the Bureau. The key recommendations were to (1) validate the materials and measure relative effectiveness of media formats; (2) survey mines for training resources and conditions - match materials to user capabilities, rather than selection state of the art technology/media; (3) develop job performance aids (JPAs) rather than simulators; (4) create a style/media/JPA development guide for use in future projects of this kind.

Jan 1, 1982