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By Jerry Dolph

Hecla Mining's Lucky Friday Mine, located beneath the town of Mullan, ID, has been shaken since the 1960s by many deep underground rock bursts. The largest rock burst carried a magnitude of 3.5 on the Richter Scale. It occurred in 1969 when all of the stopes on a level approached an upper level at the same elevation. After that, a stair-step pattern was used to give the mine's levels more of an "arch." The article is an account of one of the more ferocious bursts to hit the miners of the Lucky Friday. I say "miners" instead of "mine" because I was there and it was a very personal experience for me. I had been working at the Lucky Friday for six years. During that time, I had heard and felt thousands of air blasts. In fact, in the early spring of 1986, the mine was experiencing as many as 1000 air blasts an hour, of different intensi¬ties, of course. Most of them sounded like popcorn popping. There were also a few bumps and occasionally a real boomer. That day did not seem any different

Jan 1, 1994

By M. H. Kline, Wing G. Agew

"INTRODUCTION The Watson tract was first prospected in 1908, and ore consisting of concretionary psilomelane and wad was found in the bedded residual clays. A small mill using a log washer and jigs was constructed for concentrating the ores -on the bank of Mudhole Run, and it is reported that a few wagon¬loads of ore were shipped via the Norfolk & Western Railway. The operation was of short duration.During World War I, the area was seriously studied by the Federal Geological Survey and Virginia Geological Survey. The Virginia Geological Survey, in Bulletin 173/ reporting the work, lists the property among the few recommended for further exploration.When the shortage of manganese ores in the United States became imminent, the Bureau of Mines was authorized by the 76th Congress, under the Strategic Materials Act, to prospect and explore for manganese. Upon the recommendation of the Federal Geological Survey, a project to undertake this work was started at the old Watson mine in January 1941 and continued until August of the same year."

Apr 1, 1948

By J. L. Furtney, C. Fairhurst

"Although global mineral resources are considered to be adequate to meet the needs of a rapidly growing world population, the United States is becoming increasingly dependent on imports. This could have implications for both the economy and national security. The US is a country with a strong tradition of leadership in science and technology. Impressive advances in autonomous underground mining systems reduce the adverse effects of heat and humidity in deep mines and focus renewed attention on ground control. Developments in computing power open opportunities to develop improved understanding of the important role of discontinuities (faults and fracture systems) and more effective design of deep excavations. Establishment of mining R&D Centers at leading US research universities, jointly funded by industry and US federal agencies is recommended as an effective step for the nation to remain an influential partner in world mining. INTRODUCTION. “None of the arts is older than agriculture, but that of metals is no less ancient.. . for no mortal man ever tilled a field without implements. If we remove metals from the service of man, all methods of protecting and sustaining health and more carefully preserving the course of life are done away with.” Agricola (1558)i Homo sapiens, generally acknowledged as the species from which modern Man has evolved, is considered to have originated in Swaziland some 100,000-200,000 years ago. Evidence of use of minerals in that region has been dated to earlier than 40,000 BC.ii Today, a large fraction of the elements of the Periodic Table are derived from minerals, and finding new applications in development of innovative technologies. Agricola’s comments are as applicable today as ever.iii Metals such as copper, tin, lead, iron and aluminum were mined and smelted several thousands of years BC. It was not until the Industrial Revolution, started in the latter half of the 17th Century in Northern England, where coal was available as an energy source, and iron as the basis for fabricating machinery, that dramatic change to society began to occur. Human toil was replaced by far more powerful machines. Rural communities migrated to work in factories in urban areas. Rapid transportation over long distances became possible, leading eventually to the world of today. The change spread to other parts of the world, bringing wealth and power. Although now well established in some regions, the Revolution has still to arrive in many other parts of the world. This can be seen in Figure 1, which shows the relative wealth, or ‘Standard of Living’ as measured by the GDP/capita, of regions around the world. Regions such as North America, Europe, and Australasia iv are seen to have the highest standard. Thanks to today’s global communications systems, regions with relatively low GDP/capita are well aware of ‘how others live’ – and eager to emulate them."

Jan 1, 2018

By Arnaud Colson

1 Good morning ladies and gentlemen. Let me first thank you for welcoming me to this international congress. I?ll have the pleasure to explain to you how the Lafarge group works on its quarry rehabilitation. I will deal with the way quarry rehabilitation has affected all branches of the group trough a global approach. 2 Quarries often are a subject of controversy dividing those are for and those who are against. My purpose is rather to examine where factors of progress lay and how in a quarry such as Lafarge we can include quarry rehabilitation, which is so fundamental dimension of our process. 3 - 4 As these two photos of French quarry show taking into account the environment in the quarry industry has been a recent preoccupation. In less than a century rehabilitation has a dramatically evolved in a positive way. Consequently our group integrate an ecological dimension in its activity. It?s an ethical question as well as a personal view of our role as a responsible industrial group. 5 My presentation is built around 4 points: I?ll begin by explaining why it?s our responsibility to rehabilitate quarries. I?ll go on to fill you in on the method of the project. After that I?ll outline the expected results. Finally I?ll talk about the rest of the project and the way we can ensure this know how.

Jan 1, 2002

By Thomas Fraser

IN a Nation-wide appraisal of coking-coal reserves and of the feasibility of expanding them by upgrading marginal coals, it is natural that the Pittsburgh region of Pennsylvania should be considered first. Here, where the American iron and steel industry started, the Pittsburgh coal bed is of paramount importance. The use of coke in iron blast furnaces is said to have begun with the discovery that good blast-furnace fuel could readily be made by a simple method of coking Pittsburgh coal. To the present time, the prosperity of the steel industry has depended largely on utilization of this great coal reserve and the cheap transportation afforded by the Monongahela River system. OBJECT AND SCOPE OF INVESTIGATION The initial project in the study of upgrading marginal coking coals was laid out in this area, which contains large reserves of Pittsburgh coal contiguous to the Monongahela and its navigable tributaries. Much of the Pittsburgh coal remaining here is known to have a high sulfur content. The problem of reducing the sulfur to meet metallurgical requirements already has received much attention, and it is considered to be one of the most difficult technologic problems in the field of coal washing.

Jan 1, 1950

By A. Renton Amell

The rate of dissolution of U02 was measured in acid solutions similar to those used for in situ leaching, with S04 of 10-1.82 to 10-4 M, Fe(III) of 10-2 to 10-4 M and pH's of 1.1 to 2.3. The dependence of dissolution rate on pH was small and inconsistent, probably reflecting the combined effects of a very weakly polar oxidizing complex, probably FeSO4+, and a nearly neutral U02 surface. Differences in the state of the U02 surface may explain this variability as well as contrasts between these results and results reported in other work. Changing either S04 or Fe(III) concentrations significantly affects dissolution rates. Increasing low sulfate concentrations in solutions containing 10 2 M Fe(III) at pH 2 results in formation of FeSO4+. In such solutions, rates increased with (S04)/(Fe(III)) up to 1:30, thereby indicating that the oxidation of U02 by FeSO4 is more rapid than by Fe3+. However, the dissolution rate decreased at higher (SO4)/ (Fe(III)), due either to sorption of SO42- on the UO2 surface or to formation of other less reactive sulfate complexes such as Fe(S04)2 or FeHSO4+ However, Fe(III) concentration is the dominant factor in determining solution rates. The rate was directly proportional to ferric iron concentration, indicating that the rate-determining step of the dissolution reaction is a single-electron oxidation by a ferric complex. Dissolution rates were lower in solutions of 0.1 and 1.0% H202 (0.029 and 0.29 M) than at similar concentrations of ferric iron because of formation of an insoluble surface coating of uranium peroxide, UO4?4H20. This phase may limit the value of hydrogen peroxide as an oxidant in lixiviants, not only by its very low solubility, but perhaps also by filling pores and reducing permeability in the ore body.

Jan 1, 1978

By Baafi EY, Chatterjee PK

The quality of mine planning decisions ultimately depends on reliable estimates of the characteristics of the orebody. The quant- ifiable factors such as grades or thickness can be estimated from field data gathered from outcrops or exploratory drillholes. Since outcrop data is necessarily limited to the periphery of a deposit, extensive drilling generally is required. This paper outlines a method for selecting the number and location of additional exploratory boreholes using an iterative procedure based on a mathematical optimization concept called fixed point theory. The method is illustrated through its application to an exploratory drilling program for a coal mine where optimized locations gave a lower estimate of regional and block variances than a manual Choice.

Jan 1, 1986

By Michael J. Sapko, Eric S. Weiss, Kenneth L. Cashdollar

A fundamental safety research area for the National Institute for Occupational Safety and Health (NIOSH) is to eliminate the occurrence of coal mine explosions or to mitigate their effects. One approach is to develop and evaluate new and innovative seal designs that provide increased explosion protection for mining personnel. The NIOSH Pittsburgh Research Laboratory (PRL) cooperated with HeiTech Corp. of Virginia, Barclay Mowlem Construction Ltd. of Queensland, Australia, and the Mine Safety and Health Administration (MSHA) in three separate research programs to evaluate the strength characteristics and air leakage resistance of numerous innovative seal designs and ventilation control structures for use in underground coal mines. For each phase of the program, various full-scale seals, stoppings, and an overcast design were constructed in PRL's Lake Lynn Experimental Mine near Fairchance, Fayette County, PA. The seals and stoppings were built in crosscuts and were subjected to explosions to evaluate their strengths. Four pumpable cementitious seal designs ranging in thickness from 610 to 915 mm (24 to 36 in) were evaluated in the first cost-reimbursable research program with HeiTech Corp. A simple wooden framework with brattice liner was used as a form to contain the cementitious slurry during the curing period. As the seal designs decreased in thickness, higher compressive strength cementitious grout was used. All four seals withstood an explosion pressure pulse of at least 138 kPa (20 psi) while maintaining acceptable air leakage resistance. In the second cost-reimbursable research program with Barclay Mowlem Construction Ltd. of Australia, several innovative seal and stopping designs and an overcast design were evaluated. Each of the seal designs and the overcast side and wing walls used one or more air-inflated vinyl bladder assemblies anchored to the mine roof and hitched into the ribs and floor. The air within these bladders was displaced with a high-strength cementitious grout. The overcast deck consisted of a 200-mm ('7.8-in) thick reinforced cementitious slab. This was the first time that an overcast structure had been explosion tested under full-scale conditions. All of the seals, stoppings, and overcast design passed the air leakage tests before being subjected to a series of explosions with static pressure pulses ranging from 14 to 475 kPa (2 tab 69 psi). Instrumentation measured seal and overcast wall displacement as a function of time. The 450-mm (1 7.7-in) thick seal in the 2.8-m(9-ft) high third crosscut withstood an explosion pressure of 170 kPa (25 psi), but failed during a later test, which generated a peak static pressure of 475 kPa (69 psi) at the seal location. A similar 450-mm-thick seal in the 2.1-m (7-ft) high second crosscut withstood three explosion tests, which generated peak static pressures of 195, 205, and 370 kPa (28, 30, and 54 psi) at the seal location. Next, the overcast design withstood four explosions, which generated static overpressures ranging from 16 to 47 kPa (2.3 to 6.8 psi). A third program at the request of MSHA evaluated the effectiveness of using pressurized grout bags (Packsetter bags) along the mine roof and ribs in lieu of floor and rib hitching for a standard-type solid- concrete-block seal. This program was initiated to address an urlusual geological mining condition encountered when building seals in entries where required rib hitching is not a viable option due to soft friable coal. Results showed that the use of these quick-setting grout-filled Packsetter bags pressurized internally to 300 kPa (44 psi) not only provides a seal that can withstand a 138-kPa static pressure explosion, but also provides a sealing option where rib hitching is not possible.

Jan 1, 2003

By Sidney Katell

This study presents the economics of the hot-carbonate purification process for removing C02. It considers three variations of the process in order to meet the design specifications, which call for a feed-gas flow of 10 million standard cubic feet per hour (std.c.f.h.) with C02 inlet concentrations of 10, 20, and 30 percent and exit C02 values of 5, 2, 1, 0.5, and 0.1 percent. Inlet pressure and temperature are 350 pounds per square inch [e] (p.s.i.g.) and 300° F., respectively. Estimated capital and operating costs are shown in the following to tabulations: [ ]

Jan 1, 1960

By P. O. Osifo, K. Premlall, X. Goso, R. H. Matjie, M. R. Mulaudzi, J. R. Bunt, K. Mphahlele

This study investigates the transformation of pyrolytic spent tyre-derived char and crumb rubber into high-performance activated carbon chars for industrial wastewater remediation. Utilising an in-house macro-thermogravimetric analysis system under an argon atmosphere, spent tyre-derived activated carbon char were synthesised via physical temperature activation and aqua regia demineralisation. Comprehensive characterisation using x-ray diffraction, Raman spectroscopy, and scanning electron microscopy, revealed a predominantly amorphous structure with nanoscale crystallites (~1 nm) and active surface functional groups. Proximate analysis confirmed that both crumb rubber and leached tyre crumb rubber with aqua regia derivatives achieved favourable compositions (ash ≈ 9.6%; fixed carbon ≈ 84%), comparable to commercial activated carbon (AC). At an optimal activation temperature of 850°C, the char of tyre crumb leached with aqua regia variant exhibited a significant surface area of 300 m²/g. Crucially, the tyre crumb char produced at 850°C variant developed a pore volume of 0.8 cm³/g—effectively doubling that of commercial activated carbon (0.4 cm³/g)—facilitating the sequestration of large organic molecules. In application tests using high-strength starch wastewater, char of tyre crumb leached with aqua regia and tyre crumb char, both produced at 850°C, achieved total organic carbon removal efficiencies of 60% and 50%, respectively, bridging the performance gap between waste-derived and commercial adsorbents. These findings validate waste tyres as a viable, low-cost precursor for industrial-grade adsorbents, offering a sustainable circular economy route for tyre valorisation and reduced industrial disposal costs. Future research will focus on kinetic modelling and the recovery of zinc from spent tyre-derived activated carbon char residues.

Mar 30, 2026

By Bradford NL

The Isa Mine of Mount Isa Mines Limited produces 2.6 million tonnes of silver-lead-zinc ore annually from sub level open stopes of which approximately 40% comes from the narrow Racecourse orebodies below 15 level.Geologically the stoping environment is complicated by highly fissile shale hangingwalls and below 17 level by a high stress regime.The realization that major hangingwall failures and generally poor ground conditions could lead to serious dilution problems, and ultimately production shortfalls, prompted investigations into the use of low strength explosives.

Jan 1, 1985

Maximising margins in today's competitive international commodity markets demands superior productivity. This requires more than simply selecting the best equipment. It requires efficient production and commercial processes together with management systems recognised as international best practice. This paper introduces an integrated way of working that includes management systems for successfully changing work practices and attitudes, developing managers and increasing accountability. It provides an improvement methodology that includes systematic involvement of people in true continuous improvement of processes for maximising productivity and safety while minimising costs. Even though the principles are proven in all industry sectors worldwide, they are not always used correctly. This paper provides examples of traditional performance measurement systems to show how managers miss opportunities to control and improve both production and supporting service processes. It also describes the basic methodology for correct use of the principles and provides examples of correct implementation of modem systems in mining. The charts from actual mining case studies will be elaborated upon in the conference presentation. This paper's main aim is to provide background material for the presentation by introducing integrated principles for building best practice management systems for superior productivity and safety - for higher margins.

Jan 1, 1996

CONSTRUCTED WETLANDS (CWs) ?Human-Constructed ?Built Specifically to Remove Contaminants ?Can Treat a Wide Variety of Wastewaters Including Stormwater(SW) ?Three Major Kinds ?Pond Wetlands ?Free Water Surface Wetlands (FWS) ?Sub-Surface Flow Wetlands (SSF) ?HSSF & VSSF

May 1, 2009

By A. Bruynesteyn

Many papers 'have been publihed on the role of the bacterium.Thiobacillus ferrooxidans in the oxidation of reduced sulfur compounds, and years of research have established the following environmental factors, which influence biological oxidation. 1. Oxygen is required for the oxidation of reduced sulfur compounds to the sulfate form. Sufficient oxygen. is available from the air, consequently, it is of importance to get the air to the bacteria. 2. The bacteria are active in the pH range 1.4 3.5. Maximum activity occurs at pH 2..0 - 2.8. 3. -In order to allow the bacterial populations to expand, certain essential nutrients must be available. Nitrogen has to be supplied for the production of body protein, and ammonia is the source most readily accepted by the bacteria. Carbon dioxide is the only utilizable source of carbon and the small amounts available in air are the primary source of this element. Small amounts of phosphate, manganese,, potassium,. calcium. and magnesium are also required. These trace minerals are available from the water and host rock in sufficient quantities. 4. Water is required as a carrier for the oxygen carbon dioxide and other nutrients, as-well as a solvent for the metallic sulfates produced. The bacteria are motile and the water allows the bacterial populations to spread:: bacterial activity ceases if the equilibrium relative humidity drops below 100%. 5.-optimum bacterial activity occurs at temperatures of 34 - 35°.C (93 -.95° F). All activity ceases above 45° C. At lower temperatures, activity its dramatically decreased, but there is still a significant amount at 10 - 11° C.- Thiobacillus ferruoxidans has been isolated from a mine with a year round temperature of 3° C. 6. Unpublished results from our laboratory show that biological leach ore oxidation takes place during the rest periods at the same rate as during the wet leaching periods providing there is a film of moisture remaining around the particles. Optimum conditions can be readily achieved in the laboratory, but application of our laboratory knowledge to commercial leaching dumps is riot as simple. Attempts to achieve improved environmental conditions for the bacteria in leaching dumps would require substantial capital investment and careful planning of leaching operations. This paper

Jan 1, 1972

By Fujio Ishii

The deoxidation of liquid nickel and nickel binary alloys with silicon has been determined at temperatures between 1500°C and 1650°C using quartz crucibles in order to investigate the deoxidation of nickel based alloys. The equilibrium constant of the deoxidation reaction in liquid nickel and the effects of the different alloying elements such as chromium, molybdenum, tungsten, iron, cobalt and coppcr on the activity coefficient of oxygen in liquid nickel have been established.

Jan 1, 1993

Conveyor belt haulage offers the advan tages of continuity of operation, minimum labour requirements, and the ability to handle large volumes of material over extended periods. However, breakdown of critical con- veyors in the system can cause undue and substantial losses in production output at the working faces, unless adequate surge bin capacity is incorporated in the haulage system. A conveyor belt simulation programme, code name 'Beltsim' was developed by Bucklen et al (1968) at the Virginia Polytechnic Institute in the U.S.A. and provides a quantitative measure of the performance of a conveyor belt network design. A limitation still exists with the computer programme and involves the inability of the programme to predict the necessary surge bin capacity to overcome conveyor belt downtime. The computer programme was modified to overcome this limitation, to simulate a con- veyor belt breakdown, and to provide a quantitative prediction of the surge bin capacity necessary to permit a modern mining system to operate effectively and continuously.

Jan 1, 1977

By KNona C. Liddell

The ion interaction model Pitzer proposed twenty years ago is today the most widely used method for calculation of osmotic coefficients and electrolyte and single ion activity coefficients in aqueous solutions. This is due in part to the accuracy of the results that have been obtained for many concentrated electrolytes. An additional factor is that, compared to alternative activity coefficient models, there are many more parameter values available for the Pitzer equations. The important features of this model are reviewed. Published parameter values for Co, Ni, Cu, Zn and Fe are tabulated, and applications of interest in the aqueous processing of these metals are described.

Jan 1, 1993

"3.1. IntroductionAmong the six platinum-group elements (POE), four have identical cubic symmetry, two identical hexagonal symmetry (Table 3.1). Despite crystallographic differences, there is a clear relationship expressed in the chemistries of the POE: they tend to be mutually soluble in one another and can frequently substitute for one another in compounds with other elements. This chapter consolidates the data on phase relations of the POE and the compounds they form with elements selected for their known or potentially important mineralogical significance- As, Bi, Cu, Fe, Hg, In, Ni, Pb, S, Sb, Se, Sn and Te-together with selected data for the occurrence of POE in certain elements such as Au and Ag, and compounds such as FeS. Resources used to compile the data are those available from the chemical, mineralogical and metallurgical literature. First each element is discussed, with composition limits of solid solutions drawn from binary phase diagrams. Single element data are followed by a discussion of the relevant binary systems and a tabulation of data for binary compounds found in those systems (Table 3.2). Tables and diagrams for the ternary and quaternary systems for which information is available follow, and finally the very limited information on the solubility of POE in mineralogically important elements and compounds is presented.The chemical, mineralogical and metallurgical literature on the unary and binary systems is extensive and widely scattered in many languages and publications; fortunately, most of the data needed to compile this chapter can be found in reliable compendia. The most useful and most recent of these works is by Moffatt (1979), because it provides a ready index to all material relating to binary systems listed in previous compendia; furthermore, the Moffatt compendium will reportably be kept up to date by annual supplements."

Jan 1, 1979

By Irwan Halim, Seung Han Kim

This paper will describe design of precast segmental tunnel lining for the Pawtucket CSO Tunnel Project in Providence, Rhode Island. The tunnel is 11,700 LF long with 30-foot finished diameter to be constructed in complex sedimentary rocks. Special features of the segments include a large keystone and no connector used on radial joints. The typical segments will be steel fiber reinforced, and hybrid segments with additional steel rebars and shear bicones will be used around the adit openings without use of any structural framing. The important design considerations will be discussed, including special 3D segment to adit connection analyses performed.

Dec 1, 2022

THOSE NOT MARKED ARE MEMBERS; MARKED THUS ? ARE ASSOCIATES. HEAVY-FACED TYPE SIGNIFIES HONORARY MEMBERSHIP. JUNIOR ASSOCIATES ARE MARKED II. THE FIGURES AT THE END OF THE ADDRESS INDICATE THE YEAR OF ELECTION. ?AARONSON, ALFRED E Pres., Tuloma Oil Co., Unity Bldg., Tulsa, Okla. '18 ABADIE, EMILE R., Min. Engr Box 291, Porterville, Tulare Co., Cal. '76 ABBOTT, CLARENCE E., Gen'l Supt., Iron Mines Div., Tenn. Coal, Iron & R. R. Co. 1405 Minnesota Ave., Bessemer, Ala. '04 ABBOTT, LOUIS BENJAMIN, Chief Engr., Consolidation Coal Co., Elkhorn Div. Jenkins, Ky. 115 ABBOTT, ROBERT R. Met. Engr., Peerless Motor Car Co., Cleveland, Ohio. '12 ABE, ASAKA Fujitagumi Taiwan Office, Taipeh Formosa, Japan. '14 ABEEL, GEORGE H., JR., Cons. Min. Engr., 4111 Lafayette Ave., St. Louis, Mo. '18 ABEY, HIROSHI, Min. & Met. Engr., Arakawa Mine, Mitsubishi Co., Senpoku-gun, Akitaken, Japan. '17 ||ABOUCHAR, S. S., Cia. de Minerales y Metales, S. A. Santa Eulalia Unit, Apt. 70, Chihuahua, Chih., Mexico. '17 ABRAHAMS, A. I 1391 Madison Ave., New York N. Y. '14 ?ACKER, E. O'C., Met., 128 East Washington Lane, Germatown Philadelphia, Pa. '86 ACKER, WILLIAM L., Diamond Drill Contractor... Mears Bldg., Scranton, Pa. '18 ?ACKERMAN, ERNEST R., Pres., Lawrence Portland Cement Co. Plainfield, anion Co.. N. J. '15

Jan 1, 1923