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By John A. Organiscak

Enclosed cabs are a primary means of reducing equipment operators? silica dust exposure at surface mines. The National Institute for Occupational Safety and Health experimentally investigated various factor effects on cab air filtration system performance. The factors investi­gated were intake filter efficiency, intake air leakage, intake filter loading (filter flow resistance), recirculation filter use, and wind effects on cab particulate penetration. Adding an intake pressurizer fan to the filtration system was also investigated. Results indicate that intake filter efficiency and recirculation filter use were the two most influential factors on cab penetration performance. Use of the recirculation filter reduced cab penetration by usually an order of magnitude over the intake air filter alone because of the multi­plicative filtration of the cab interior air. Intake air leakage and filter loading affected the cab penetration to a lesser extent, while wind had the least impact on cab penetration between the calm and 10-mph wind velocities tested. Adding an intake pressurizer fan notably increased intake airflow and cab pressure with only minor changes to cab penetration. A mathematical model was developed that describes cab penetration in terms of intake filter efficiency, intake air quantity, intake air leakage, recirculation filter efficiency, recirculation filter quantity, and wind penetration.

Nov 1, 2008

By Paul S. Goodman

This report examines the effectiveness of bonus plans in the coal industry. The analysis uses theoretical, literature review and empirical approaches to determine the impact of bonus plans on safety and productivity in underground coal mines. The basic finding is that the modal bonus plan in underground coal mining does not have a major impact on productivity and safety indicators. The design of the plan, or organizational factors, and the process of introducing the plan all contribute to its relative ineffectiveness. Strategies and options for designing effective plans are presented.

Jan 1, 1987

By Jack V. Hill

A unique type of grinding mill liner has been developed by Waagner-Biro A.G. of Austria. This liner system, termed an angular spiral lining (.ESL), was, successfully tested by Magma Copper Company's San Manuel concentrator in both their 10 Ft x 10 Ft (3.05m x 3.05m) and 12 Ft, 6 In x 14 Ft (3.81m x 4.27m) grate discharge wet grinding ball mills. Magma Copper's savings in power and grinding balls justified conversion of more than half of their twenty-six ball mills to the ESL system.1,2 The ASL system was provided by the Capitol Castings Division of Midland Ross Corporation, the exclusive licensee for such conversions. Capitol Castings proposed the following as expected benefits from installation of an ASL system in an 18 Ft x 21 Ft (5.49m x 6.40m) overflow discharge wet grinding ball mill at the Pinto Valley Operation of Cities Service Company: "(a) Reduction of power consumption per ton of ore milled = 12%, (b) Increased throughput = 6%, (c) Reduction of ball consumption = 6%."

Jan 1, 1982

By S C. Dominy

The gravity recoverable gold (GRG) parameter reflects liberated gold or gold-dominated composite particles that can be recovered by gravity separation. Recoveries depend upon mineralogy, in situ particle size and the comminution and extraction method used. Any ore bearing >15 per cent of gold greater than 50 ¦m in size is likely to have a GRG component. The principal characterisation methodology applied is the three-stage GRG (3GRG) test, based on a 40 kg to 100 kg sample. An alternative is the single-stage GRG test (SGRG), which is generally based on a 20 kg sample. Experience has shown that GRG values can vary throughout an orebody, particularly within different grade and/or mineralogical domains. Test programs must consider sample frequency and mass. This study demonstrates the variability of GRG results based on different sample masses. Consecutive underground faces on a coarse-gold dominated quartz vein were sampled taking five different masses from each. Each sample was processed using a SGRG approach. Subsequently, each development round was batched through a small gravity production plant. The results show that the small samples understate the plant GRG and show inter-sample variability. Large samples show less variability and a SGRG closer to the plant GRG. A high SGRG broadly correlates to higher gold grades, more coarse gold and larger gold particles. These results are intuitively correct, but indicate the likely challenges of sampling for gold recovery in heterogeneous systems.CITATION:Dominy, S C, 2013. Variability of gravity recoverable gold values in relation to test sample size, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 293-302 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By E. J. Gleim

A list of permissible mine equipment, tested and approved by the Bureau of Mines previous to January 1, 1942, was published in Bureau of Mines Information Circular 7207.3/ The list of that date was complete as to equipment then available and in current use. Information Circular 7240,4/ published as a supplement thereto, listed equipment approved curing the calendar year 1943. The present list is another supplement covering approvals issued during the calendar year 1943. The items are numbered to indicate the consecutive order in which each type of machine or device was approved in its particular classification. Thus, Information Circular 7207 gave 19 drills and drilling machines on the Bureau's active list. No additional approvals were given in 1942, but the three issued in 1943 bring the total to 22. Item 102, under Loading Machines and Conveyors, also appeared in Information Circular 7207, and items 120 and 124 appeared in Information Circular 7240. These numbers are repeated here to show that approvals were granted during 1943 for additional voltages on machines previously listed for one voltage only. Equipment listed in these circulars is approved by the Bureau of Mines only when found upon inspection and test to comply with minimum standards of safety as outlined in schedules prepared on the basis of many years of experience in dealing with safety problems of the coal-mining industry. The use of such equipment in mines known to be gassy, as well as in those that may become so, is earnestly recommended in the interests of safety. This circular is published so that the industry may be kept

Jan 1, 1944

By Duluth Engineers' Club, Engineers' Club of Northern Minnesota

"The history of Duluth commences with Daniel de Greysolon du Lhut, one of the explorers of the Upper Mississippi who came to the head of the lakes in the summer of 1679. Radisson and Groseillier, and Claude Allouez, a Jesuit priest, are supposed to have visited the head of the lakes, -but there is no authentic record previous to that of du Lhut.In 1792, the fur traders established a fort at Fond du Lac, fifteen miles up the St. Louis River from Lake Superior, but within the limits of the present city •of Duluth. In the early 50's, there were a few scattering settlers at Oneota and around the George Stuntz trading post on Minnesota point. In 1855-6, the settlement on Minnesota point was called Duluth, commemorating the name du Lhut, and organized as a town in 1857. The first board of trustees and town council consisted of -William Nettleton, J. B. Culver; Robert E. Jefferson, Grin W. Rice and William Old: In 1870, the city of Duluth was incorporated, and five years later a portion of the same territory was incorporated as the village of Duluth, and the two municipal corporations were still in existence on March 1, 1887, when the city and the village of Duluth were incorporated as the present city.The first saw mill in Duluth was erected in 1856-57, on the present site of the ship canal. It cut logs from a virgin forest at the upper end of Minnesota point.The first railroad was built to the head of the lakes in 1870. The charter for this road had been granted in 1861 to the Lake Superior and Mississippi Railroad Company, afterward called the St. Paul and Duluth, and which is now a part of the Northern Pacific Railroad."

Jan 1, 1920

By Alfred Bodenlos

"El presente texto señala los acontecimientos geológicos en la Cordillera Negra y la deposición de travertino por las fuentes termales todavía activas al oeste de la población de Ticapampa. Los minerales fueron depositados principalmente como rellenos de fisuras, siendo cavernosos y en partes bandeados y sus temperaturas conocidas de formación varían desde baja hasta moderada, lo cual, además de su textura porosa, sugiere que están comprendidos entre las clases epitermal y mesotermal, según sistema propuesto por Lindgren. "

Sep 1, 1957

By Chas. F. Jackson

During the past year a special study was made of shrinkage stoping A large number of mines in the United States and Canada which employ this method were visited and their practices were discussed with the operating staffs. The operating data obtained are appended hereto. Data were also abstracted from the literature on other mines and are combined in tables with data personally secured by the author. References are made to these published articles, some of which have appeared as information circulars of the United States Bureau of Mines, in the Transactions of the American Institute of Mining and Metallurgical Engineers, and the Engineering and Mining Journal. Several of the mines referred to which have not been described in individual papers will be described in detail in information circulars to be issued by the bureau. Eventually it is planned to combine and condense the information in these circulars and present the data in bulletin form.

Jan 1, 1930

By A. J. Macdonald

Gold deposits hosted by banded iron formation (BIF) in Ontario exhibit a marked association with localized zones of deformed and hydrothermally altered BI:F . Secondary sulphides and carbonates are conspicuous. Proposed carbonate-facies IF , or exhali tes, such as green carbonate in the Larder Lake camp and ankerite veins in the Porcupine Camp are structurally controlled, hydrothermally deposited zones of carbonate replacement and fissure filling. Gold precipitation from hyd r othermal fluids in strain-generated conduits may be due to (a) plating upon secondary sulphides, (b) pH change due to carbonatization of BIF or (c) destabilization of gold in solution due to sulphidation of BIF .

Jan 1, 1984

"History - How did you get into mining and involved with SME?Unlike many past presidents, I do not come from a mining lineage. I liked math in high school and believed I wanted to be an engineer. I told my math teacher that, and he laughed in my face. I believe that humiliation is what carried me through engineering school. At the time my ability to go to college relied on how inexpensive I could make it. My brother told me that there were a lot of scholarships in mining engineering, and I should apply to mining schools. As usual, he was right and I was off to the University of Idaho to study. My first summer break I got a job with Hecla at a mine in Arizona. I was a laborer on a shotcrete crew. I knew after the first summer that I loved underground mining, and I never considered changing disciplines. Looking back, I was working in miserable conditions (hot, humid), on a miserable job (shotcrete), where I got injured, and two summer student roommates died in a car accident on the commute home after work. I had every reason to hate the industry, as I had seen virtually everything bad about what we do. But I didn’t, I loved it. I said I was good at math, I never said I was smart.I joined SME in college because I was told to by the head of the mining school, Dr. Jack Hoskins. You did what Jack told you to do. I got involved because I went to an annual meeting and the papers in the underground sessions were terrible. I refer to bad papers as the “Tensile strength on cable bolts in sub-arctic regions on Tuesday” papers. Real snoring fodder. I don’t remember who I was complaining to, but they told me to quit my grumbling and fix it. So I chaired a session, and tried to get only good quality papers, something that has been my mantra for years with the Mining & Exploration Division. I also volunteered to help the local sections too. Then one day I woke up as president.What is your opinion of the health of the mining industry?The mining industry is in bad shape. Coal is under attack and will likely never recover to its former greatness. Our President has banned new coal leases, and the state of California is forcing people it does business with to divest their interests in coal companies. And that all happened in just in a few short weeks this January. Usually in America you get a trial before you are given a death sentence, but not with coal."

Jan 1, 2015

By J. P. Gouvea

Back-analysis of two mining-induced tremors in 2011 was used to determine a modelling criterion for the entire Klerksdorp Goldfield (i.e., Vaal Reefs region). At that time, most mining operations in the region were owned by AngloGold Ashanti (AGA) and shared many geotechnical similarities. By 2018 AGA had sold off all its Klerksdorp operations to different mining companies, which continued applying the 2011 modelling criterion. As mining activities became more remote, scattered, and isolated, the extraction of isolated blocks of ground and remnants became increasingly necessary. However, the inherited criterion allowed only minimal or no mining activities at these areas. Keeping in mind that safety is the overriding consideration, an innovative numerical modelling approach, which includes the application of peak particle velocity designs, was developed to provide practitioners in the Klerksdorp Goldfield with a suitable criterion to justifiably and safely mine isolated blocks of ground and remnants. This would not always be possible if a conformist approach was used.

Mar 14, 2024

By M. van Swaay, C. E. Birchenall

A. S. lBrling (Johnson, Matthey & Co. Ltd., Laboratories)— Because of its initial emphasis upon the production of membranes by powder metallurgy and by normal casting and rolling techniques, this paper is of considerable interest to those concerned with the design and application of industrial diffusion units. As the subsequent performances of the three grades of palladium were not compared in detail, it can perhaps be concluded that specific permeabilities were very similar. A short table in which the absolute diffusion rates obtained by the Authors with their three grades of palladium were compared with those of other investigators18-25 would, however, have been of particular value in view of the very variable results obtained with this membrane material. The Authors state early in the paper that the permeability of the thoriated samples decreased in much the same way as that of the nonthoriated samples. Later, they emphasize that sintered palladium without thoria was very susceptible to poisoning and did not respond as well as the other materials to the decontamination treatment. These results, which suggest that sintered membranes are less effective than those produced by normal methods, have considerable industrial implications, and amplified experimental details would be very welcome. The results of the Authors differ in one important respect from those of other investigators. Thus, no "bleeding" was required to maintain a constant rate of diffusion, although Davis, Darling, and De Rosset found this to be necessary. Davisz3 found that "bleeding" was necessary even when the hydrogen had already been purified by diffusion through a palladium tube, and it would be of value to know the purity of the gas stream emerging from the purification train shown on Fig. 1 of the Authors' paper. The Authors show that diffusion rates varied according to the square root of the pressure difference providing that the palladium membrane was not contaminated in any way. This finding is in agreement with the results of those workers2,18,19,23,24 who diffused their hydrogen through the membrane into a partly or completely evacuated system.Those workers who did not find this square-root law dependence did not have a partial vacuum on the downstream-side of the membrane.'' The difference between the two experimental con- ditions appears to be significant, as the absolute diffusion rates per sq cm of diffusion area are lower when the square-root law dependence is not observed. While the effect could be attributable to poisoning of the membrane it is conceivable that a positive pressure on the downstream side of the membrane might influence the mechanism of diffusion. In view of the capricious behavior of palladium, factors of this type, which are likely to influence its industrial significance, should be carefully considered. M. van Swaay and C. E. Birchenall (authors' 9-eply) — Our Eq. 191 may be compared with several others for hydrogen diffusion in palladium: D = 5.95 x exp (-5770/1)' D = 3.55 x 10"3 exp (-5550/)' D = 4.3 x 10"3 exp (-5620/1')' Other values are given in the literature, but in many cases surface poisoning may have affected the results. No analysis was performed on the hydrogen gas stream after purification. It should be noted that the presence of liquid nitrogen traps near the heated membranes may have set up convection currents and provided the equivalent of "bleeding." The question of whether a partial vacuum existed on the downstream side of the membrane is not clear. Does it imply that there is something unique about the permeability measured near one atmosphere pressure? We do not believe that there is. When square root pressure dependence is not observed, diffusion rates are not measured. Is "absolute diffusion rate per sq. cm. of diffusion area" equivalent to permeability? The terminology is new to us. In any case we doubt very much that pressures of the order of several atmospheres can affect the mechanism of diffusion.

Jan 1, 1962

By P. F. Kerr

This is not a conventional professional paper. It deals mostly with personal experiences. These concern a background in applied mineralogy. Your committee asked me to do this. I accepted with a California enthusiasm which has since diminished with the approach of a Chicago winter. Nevertheless, I wish to thank your committee and also to apologize in advance for omissions and inadequate statements, as such a paper must possess. My introduction to applied mineralogy took place in 1922 at Stanford University. Physicists had recently demonstrated that crystalline powders would reflect x-rays in a systematic manner. Professor A.F. Rogers sug¬gested that significant x-ray reflections might be obtained from powdered opaque minerals. With the aid of Professor D.L. Webster in the Physics Department, I constructed an x-ray diffraction outfit. It was a crude affair, but it worked. Starting with 1924, we secured recognizable patterns of a goodly number of ore minerals (1,2,3). Today x-ray diffraction outfits are common, and a card system of mineral identification is constantly used.

Jan 1, 1981

By Michael J. Miller

The demand and supply of wollastonite has gone through a dynamic period in the 1990's. A 10% -15% growth rate of demand stimulated interest in evaluating new projects. However, the mid-1990's brought declining prices for commodity applications and natural barriers to entry for technical applications, making many of these potential projects uneconomic. Successful projects that were brought to market were done so by incumbent producers. This work examines the competitive structure of the wollastonite market by evaluating the strategic decisions of the industry leader, NYCO Minerals Inc., and a new market entrant, Orleans Resources, in an attempt to identify the environmental threats and opportunities of this industry. Results suggest new entrants like Orleans Resources face significant entry barriers for technical applications, while NYCO Minerals could improve its profitability by having less exposure to commodity applications.

Jan 1, 1999

By Rene Cane, V. I. Lakshmanan, John Starkey, Richard May

"The Agrium Kapuskasing Phosphate Operation mines and processes up to 6,000 t/d of phosphate ore. Run-of-mine crushing to minus 6 inches is done in a toothed roll-crusher, while grinding is done in a SAG/ball mill circuit with no coarse recycle classification of the SAG mill discharge. The primary grinding mill is an 18 ft. diameter x 9 ft. EGL, 1500 HP variable speed SAG mill and the secondary mill is a 13 ft. diameter x 21 ft. long, 2000 HP fixed speed, ball mill. When hard ore was treated, the SAG mill restricted the tonnage that could be ground. When soft ore was treated, the ball mill and spiral classifier overloaded and restricted throughput.Recommendations from a plant benchmark and an ore hardness testing program, on how to better utilize installed energy in the Agrium SAG mill when treating soft ore, and how to obtain best results when treating hard ore, were checked in a pilot plant investigation in the 3 ft. diameter Starkey-PRO Pilot SAG Mill. Correlation between the ore hardness testing and the results from the 3’ Pilot SAG mill was very good. In addition, the work indicated the results that could be expected for the different ore types when using either smaller SAG discharge grates and/or a vibrating screen with 10 mesh square opening cloth.INTRODUCTIONAgrium Kapuskasing Phosphate Operation consists of a 6800 t/d open pit mine and a concentrator, near the Town of Kapuskasing in Northern Ontario. The two major ore types are sandy ore and cemented ore. Sandy ore is fine, soft and easy to grind in the SAG mill while cemented ore is harder, more blocky and difficult to grind in the SAG mill. The ratio of sandy to cemented ore in the deposit is thought to be in the order of 80:20 but can range as high as 5050, so it was important for the grinding circuit to have the ability to treat sandy ore alone."

Jan 1, 2002

By M. Li, W. R. Reed, J. P. Rider, J. D. Potts

"The National Institute for Occupational Safety and Health (NIOSH) has recently developed a series of validated models utilizing computational fluid dynamics (CFD) to study the effects of air-blocking shelves on airflows and respirable dust distribution associated with medium-sized surface blasthole drill shrouds as part of a dry dust collector system. Using validated CFD models, three different air-blocking shelves were included in this study: a 15.2-cm (6-in.) wide shelf; a 7.6-cm (3-in.) wide shelf; and a 7.6-cm (3-in.) wide shelf at four different shelf heights. In addition, the dust-collector-to-bailing airflow ratios of 1.75:1, 1.5:1, 1.25:1, and 1:1 were evaluated for the 15.2-cm (6-in.) wide air-blocking shelf. This paper describes the methodology used to develop the CFD models. The effects of air-blocking shelves and dust-collector-to-bailing airflow ratios were identified by the study, and problem regions were revealed under certain conditions. The simulation results could be used for future development of dust control methods, particularly to address respirable silica dust, for a surface mine blasthole drill shroud.INTRODUCTION Surface blasthole drilling can generate considerable amounts of respirable silica dust. These high dust concentrations can be exacerbated by the high silica content as drilling cuts through silica-bearing materials such as sandstone and shale, causing overexposures for miners to respirable silica dust. These overexposures can lead to silicosis, an occupational lung disease that has no cure and is often fatal. A review of the Mine Safety and Health Administration (MSHA) respirable silica dust sample database from 2010 to 2016 for metal/nonmetal mining shows the following overexposure rates for occupations related to blasthole drilling: • 14.1% of rotary air drillers were overexposed to respirable silica dust (22 out of 156 samples) • 5.8% of rotary drillers were overexposed to respirable silica dust (9 out of 155 samples) • 7.3% of drill helpers were overexposed to respirable silica dust (3 out of 41 samples) • 7.5% of blaster/shotfirer were overexposed to respirable silica dust (3 out of 40 samples) Of significant interest is an x-ray surveillance study recently completed under the NIOSH Enhanced Coal Workers’ Health Surveillance Program (ECWHSP). This program offered free chest radiographs to surface coal miners in 16 states. Pneumoconiosis was found among 2.0% of the 2,328 screened miners with at least 1 year of mining tenure. Twelve miners had radiographic changes consistent with progressive massive fibrosis, and 9 of these 12 miners reported no underground mining tenure. All but 1 of the 9 miners worked at occupations that were in the vicinity of blasthole drilling, either as a driller, blaster, or blast crew member [1]."

Jan 1, 2018

By M. Li, W. R. Reed, J. P. Rider, J. D. Potts

The National Institute for Occupational Safety and Health (NIOSH) has recently developed a series of validated models utilizing computational fluid dynamics (CFD) to study the effects of air-blocking shelves on airflows and respirable dust distribution associated with medium-sized surface blasthole drill shrouds as part of a dry dust collector system. Using validated CFD models, three different air-blocking shelves were included in this study: a 15.2-cm (6-in.) wide shelf; a 7.6-cm (3-in.) wide shelf; and a 7.6-cm (3-in.) wide shelf at four different shelf heights. In addition, the dust-collector-to-bailing airflow ratios of 1.75:1, 1.5:1, 1.25:1, and 1:1 were evaluated for the 15.2-cm (6-in.) wide air-blocking shelf. This paper describes the methodology used to develop the CFD models. The effects of air-blocking shelves and dust-collector-to-bailing airflow ratios were identified by the study, and problem regions were revealed under certain conditions. The simulation results could be used for future development of dust control methods, particularly to address respirable silica dust, for a surface mine blasthole drill shroud. INTRODUCTION Surface blasthole drilling can generate considerable amounts of respirable silica dust. These high dust concentrations can be exacerbated by the high silica content as drilling cuts through silica-bearing materials such as sandstone and shale, causing overexposures for miners to respirable silica dust. These overexposures can lead to silicosis, an occupational lung disease that has no cure and is often fatal. A review of the Mine Safety and Health Administration (MSHA) respirable silica dust sample database from 2010 to 2016 for metal/nonmetal mining shows the following overexposure rates for occupations related to blasthole drilling: • 14.1% of rotary air drillers were overexposed to respirable silica dust (22 out of 156 samples) • 5.8% of rotary drillers were overexposed to respirable silica dust (9 out of 155 samples) • 7.3% of drill helpers were overexposed to respirable silica dust (3 out of 41 samples) • 7.5% of blaster/shotfirer were overexposed to respirable silica dust (3 out of 40 samples) Of significant interest is an x-ray surveillance study recently completed under the NIOSH Enhanced Coal Workers’ Health Surveillance Program (ECWHSP). This program offered free chest radiographs to surface coal miners in 16 states. Pneumoconiosis was found among 2.0% of the 2,328 screened miners with at least 1 year of mining tenure. Twelve miners had radiographic changes consistent with progressive massive fibrosis, and 9 of these 12 miners reported no underground mining tenure. All but 1 of the 9 miners worked at occupations that were in the vicinity of blasthole drilling, either as a driller, blaster, or blast crew member [1].

Jan 1, 2019

By Edward H. Eisenbrey

This paper is primarily concerned with the exploration for massive sulphide orebodies. In a discussion of this type, it seems appropriate to establish a few definitions so that all parties may consider the same beast and its habitat. First, the term "massive sulphides", as used here, not only denotes a body of mineralized rock containing in excess of 50% sulphides by volume, but a mass of sulphides that respond as a conductor to the electromagnetic (EM) systems currently in use in exploration. "Disseminated sulphides" refer to all of those sulphide occurrences that respond to the Induced Polarization (IP) geophysical methods most commonly in use in porphyry copper exploration. This latter definition may also include the disseminated sulphide halos so frequently found associated with massive mineralization as well as banded and stringer sulphide mineralization. It is plain to see that these two end members of our definitions can easily blend into each other. The term "volcanogenic" refers here to any and all geologic processes that have their origin in volcanic activity. Thus we are concerned here with the exploration for massive sulphide ore deposits derived from and affected by contemporaneous and post mineral volcanic activity. Furthermore, most massive sulphide deposits are apparently formed in a submarine environment, deposited with extrusive rocks and sediments and/or chemical hot spring accumulations, then enclosed and protected by the addition of more volcanic and sedimentary material then, probably folded and deformed into one of their myriad of shapes.

Jan 1, 1973

By A. B. Hooker, L. C. IlsLey

Explosives have been fired electrically for several decades. Mountains have been tunneled, deep shafts sunk, extensive coal and metal mine workings excavated and, in times of war, railroads, buildings, bridges, and fortifications have been destroyed by means of electrically fired explosives. Modern engineering depends so much on explosives that their safe and efficient handling and especially their detonation are of prime importance to all those connected with the use of explosive agents. Electric shot-firing is only one method of igniting explosives, but it is rapidly spreading and because of certain inherent safety features should be encouraged. Data collected by the Bureau of Mines indicate that in the United States a large percentage of the blasting in quarries, shafts,· and tunnels, and from 15 to 25 per cent of the blasts in mining operations, are set off electrically. The Bureau of Mines is interested in electric shot-firing because of its use in mining, and especially because electric methods, when properly applied, are undoubtedly safer than other methods commonly used. Electrical problems of many kinds must be solved in dealing with the various phases of electric shot-firing. Success in using an electric detonator is closely linked with the resistance of its bridge, the resistance of its leg wires, and the insulation of its current-carrying parts. The proper layout of a circuit where a number of shots are to be fired simultaneously depends not only on the types of detonators that are used and their arrangement and interconnections, but also on the size and insulation of the wire leading back to the source of power, and even on the source of power itself. Various types of electric shot-firing machines have been developed, and these offer still another field for study. In investigations of electric detonators and electric blasting equipment, the oscillograph is valuable because it can record electrical activity over very short intervals of time. By its use more complete information about electrical performance can be obtained than by any other means.

Jan 1, 1926

By S M. Jowitt, G M. Mudd

"The mining industry is the source for the vast majority of the metal, mineral and energy resources we use on a daily basis. New deposits are discovered over time and are developed into mines before being rehabilitated – a sequence that when repeated can help contribute to the noble notion of ‘sustainable development’, despite the generic concept of mining being the unsustainable consumption of non-renewable resources. The scale of the modern mining industry is immense – from iron ore and coal to base and precious metals, modern mines are sometimes hundreds or thousands of times bigger than their long lost historic ancestors. We also live in a world with emerging and increasing demands for so-called technology metals (aka ‘critical’, ‘e-tech’ or ‘specialty’ metals) that are needed to feed the rapid growth in renewable energy (especially solar photovoltaic panels and wind turbines), consumer electronics, sophisticated military technologies and super alloys, amongst other uses. These elements include the rare earth elements, indium, germanium, tellurium, rhenium, selenium, gallium and many others, most of which had few or no known uses in the recent past. Although the mining industry has been successful in developing ever larger mines and increasing the scale of production, the key issues underlying the future of the industry are declining ore grades, increased tailings and waste rock generation, the presence of toxic or other impurities, balancing the economics of primary and secondary products, stricter environmental conditions, more difficult exploration, increasing community expectations, as well as the processing of more complex or refractory ores, let alone the recent volatility in world commodity markets. Here, we synthesise our recent research on many of these various issues, focusing on the need to link all areas within the mining chain from mineral resources through mining to environmental performance in order to ensure we obtain the most out of our modern mining effort. The paper presents a unique and detailed assessment of the sustainability challenges and opportunities facing modern mining – and geometallurgical thinking is at the heart of this conundrum.CITATION:Mudd, G M, Jowitt, S M, 2016. From Mineral Resources to Sustainable Mining – the Key Trends to Unlock the Holy Grail?, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 37–54 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016