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A major emphasis of the U.S. Bureau of Mines is to perform research on the prevention of fatal accidents at mining operations. The leading cause of fatalities in the underground coal mining industry is groundfalls. This proceedings volume presents several new developments that are helping to prevent fatalities and reduce injuries by groundfalls. The papers focus on the problem from two different perspectives. About half of the papers present information and techniques that can be used to train and motivate miners to protect themselves from groundfalls. The other papers explain how to identify and respond to various geologic conditions that affect the stability of the mine roof. Of the 95 groundfall fatalities that occurred during 1986-90, 75% took place in Kentucky, West Virginia, and Virginia. The rate of groundfall fatalities was much higher at small mines. During 1986-90, the rate of groundfall fatalities at mines employing fewer than 20 people was 4.3 times higher than the rate for larger mines. Because so many groundfall fatalities are occurring at relatively small mines in the southern Appalachian coalfields, many of the papers focus specifically on the needs of this category of mine operations.

Jan 1, 1992

By R. D. Leitch

Spontaneous firing of coal during storage end even during shipment has long been a serious problem, especially in some regions and with some coals, and methods for preventing such firing have been investigated at intervals for more than 70 years. Spontaneous or other firing of coal waste, either outside or inside mines, has also been a problem probably for as long as mining has been practiced extensively. Much trouble has been caused by such fires, and much money has been spent in attempts to extinguish them. It is known generally that surface waste banks in bituminous-coal fields are very likely to take fire sooner or later, but it is not known so generally that anthracite refuse-bark fires also are common and that at least some of them are more serious in their effect and results than being regarded merely as a nuisance. There surface refuse fires probably would have attracted much more than local attention long ago had it not been that they usually cause no more serious trouble than air pollution. A few supposedly effective methods of preventing or extinguishing spontaneous fires have been reported rather recently. Unless one or more of these prove to be widely applicable, methods of solving these problems are no more certain today than they have been for many years.

Jan 1, 1940

By L. A. Neumeier

The Bureau of Mines evaluated the properties of a Zn-0.75 pct Cu-0.12 pct Ti alloy extruded at temperatures between 400° and 720° F. The extrusions were made with a reduction ratio of 28-to-l and at relatively slow speed. Rod was also extruded at 560° and 640° F with a reduction of 255-to-l. With increased extrusion, temperature, extrusion pressures decreased substantially and creep resistance of the rod improved significantly. Coefficients of thermal expansion were low in the long rod dimension. Microstructures, hardness, and tensile properties were also evaluated, and a limited evaluation was made of bend ductility at 32° F for the rod extruded with the 255-to-1 reduction.

Jan 1, 1969

By James R. Boyle

The value of Alabama's nonfuel mineral production in 1980 was $328.6 million, a decrease of $7.8 million from 1979. Cement, crushed stone, lime, clays, and sand and gravel continued as the major commodities produced. Alabama led the Nation in the production of crushed marble; was second in bauxite; third in native asphalt, ferroalloys, kaolin, and oyster shell; fourth in dimension marble, masonry cement, and bentonite; and fifth in fire clay and lime. Alabama ranked in the top 20 States in total value of non-metallic minerals produced. Adverse economic conditions in the construction and metals industries impacted on the minerals industry in Alabama. Mineral producers supplying raw or finished materials to these industries experienced periodic reductions in sales during the year. Unit price increases did not keep up with inflation.

Jan 1, 1982

By Sara Anderson, Rachel Nicholls, Tim Chapman, Janice Windle

"In city center sites around the world, and in particular in London, foundation reuse is becoming increasingly widespread as the ground is filled with detritus from previous developments. This paper sets out a systematic framework to consider the need for and benefits of foundation reuse and key issues to be resolved for foundation reuse to be successfully adopted on redevelopment projects. Once foundation reuse has been identified as a potential foundation solution there are several key stages in the design and construction process where the decision to reuse foundations needs to be assessed. The paper concludes by emphasising the importance of ensuring that the foundations being installed now can more easily be reused in the future.INTRODUCTIONThe concept of re-using foundations is not new, and has been adopted on an isolated project-byproject basis for many years. However, over the past decade, interest in the potential of reusing existing piles and caissons within Europe has increased significantly, with a growing interest in the United States of America and Japan. The need has been driven by necessity: on many urban sites the space available for new foundations diminishes with each new set of piles, and these problems can only grow in the future.Initiatives such as the European Union's RuFUS (Re-use of Foundations for Urban Sites) research project have resulted in identification of the key issues for technical viability and risk that have previously hampered potential foundation reuse projects.There is a need to define a systematic approach to the reuse of foundations so that the risks associated with reuse can be identified, managed and mitigated. This requires improvements in knowledge to provide confidence in the long term behaviour of the foundation support and address the risks involved in reusing existing foundations to overcome perceived obstacles in making foundation reuse a realistic option for many sites."

Jan 1, 2005

Viscosity measurement was carried out over a narrow range of silica content around the fayalite composition. A wide range of temperature and oxygen potential was covered where the slag was completely liquid. In order to keep the slag composition and the Fe3+/Fe2+ratio constant, theCO2/CO ratio was kept constant as the temperature was varied. Increasing the Fe3+content has little effect on viscosity for slags with a silica mole fraction of 0.31. At higher silica contents, increasing the Fe3+content brings about a small decrease in the viscosity.

Jan 1, 2004

By R. Vracar, D. Sinadinovic, Ž. Kamberovic

The paper presents a study on the oxidation of polymetallic gold ore by oxygen in an autoclave. It presents optimum parameters of autoclave leaching of sulphide refractory ore in self-generated sulphuric acid solutions aiming to get products with favourable technological characteristics from which precious and other useful metals can be recovered. A high partial oxygen pressure (1.5 MPa to 2 MPa), high leaching temperature (190°C to 200°C), pulp density 80 g/L to 240 g/L, ore fraction size 76 µm and leaching time up to 4 hours yield good results in rich ores. The full extent of copper and zinc conversion as well as a high extent of iron conversion has been achieved, while lead, gold and silver and a minor part of iron remain as a solid residue among gangue minerals.

Jan 1, 2001

Once every three years the eyes of the construction and mining industry?s turn to Munich, Germany for the bauma trade fair and exhibition. From April 19-25, Messe München International (MMI) will host the 29th edition of this massive show that, despite the recent recession and global financial struggles, has grown yet again. The show, which is completely booked, will take place on a record 555,000 m2 (5.9 million sq ft) of indoor and outdoor exhibition space at the New Munich Trade Fair Centre. More than 3,000 exhibitors are expected to make use of this event. To prepare for the show that highlights some of the largest and most impressive construction and mining equipment in the world, Messe München began working months in advance on getting the infrastructure on the open-air site ready, in time for the arrival of the gigantic machinery exhibits, which started to arrive in March. Part of the preparations include a new entrance at the northwest corner of the exhibition center that was built to regulate visitor flow better. This should help with bauma considering that in 2007 more than 500,000 visitors passed through the gates. ?Although in 2010 the construction machinery sector in many markets worldwide will be recovering only slowly from the recession, we are pleased to report that we are seeing strong demand for exhibition space. This shows that exhibitors regard participation in the world?s leading trade fair bauma as a must, although many are at present having to make cuts in their advertising and trade-fair budgets. We have been particularly surprised by the strong demand for space from exhibitors from markets like China, India and Turkey. The fair is fully booked and many more companies are on the waiting list,? said Eugen Egetenmeir, managing director of Messe München. More than 50 percent of the exhibitors at bauma 2010 come from countries outside of Germany. While the show?s primary focus is on the construction section, it is not as if the mining sector will be difficult to find. With some of the largest equipment in world on display in section C2 (Fig. 1), the mining industry is sure to be well-represented.

Jan 4, 2010

By V. Krupa, E. Lazarova

A method is proposed for the continuous calulation of a rock mass in real time while tunnelling with a TBM. Rock properties are investigated through models of the fracture stress under the disc cutters, the quasi-shear stress between the disc cutters and the specific energy of cutting under the disc cutters. Comparison of theoretical and monitored data of cutting specific energy can be used to determine theoretically the prevailing shape and size of the bulk debris. The shape and size of the chips from a given rock vary with the boring parameters. Introducing shape and volume corrections into the models of the evaluated stresses suppresses the influence of the boring regime and allows the rock properties to become dominant

Dec 1, 1996

By Samer R. Rabab?ah

As part of the PHX Sky TrainTM project at Phoenix Sky Harbor International Airport in Phoenix, Arizona, the existing traffic lanes at the 44th Street underpass below the Union Pacific Railroad (UPRR) Bridge will be shifted to accommodate the people mover guideway. The proposed reconfiguration and reconstruction of 44th Street required the utilization of micropiles and permeation grouting to resist the lateral forces induced by cutting into the slope below the existing bridge abutment footing. This paper discusses the evaluation of the existing bridge abutment, including analysis of the original foundation system, and design, installation and testing of a new micropile-supported retaining wall to support the cut slope below the existing bridge abutment foundation. A monitoring program was implemented during construction to evaluate the short- and long-term performance of the bridge abutment. Instrumentation included survey monitoring points, inclinometers, tiltmeters and crack gauges. A micropile load testing program was conducted to verify design assumptions concerning micropile axial and lateral loading. Numerical analyses (using PLAXIS software) were performed to predict the short- and long-term behavior of both the abutment wall and the bridge foundations. Movement data collected from the monitoring program indicate that the wall and bridge foundations are performing satisfactorily and within the general bounds of predicted movements. The results from the numerical modeling using PLAXIS software showed that the proposed solution is deemed adequate to provide the needed global stability with an acceptable factor of safety, along with acceptable deformation.

Jan 1, 2011

By S. Hardy

The paper describes state of the art non-linear analyses of the pile groups that were employed during the raising of the 133m high triumphal arch which forms the centre piece of the new Wembley stadium in North London. The deformation behaviour of these piles groups was critical during the lifting process, due to the slendemess of the arch structure. The issue was made more critical by the high profile nature of the project. The results of Class A (Lambe (1973)) predictions of the pile group movements are compared with observed displacements and rotations which were accurately measured on site. To illustrate the importance of soil non-linearity on pile group behaviour, comparison is also made with pile group analyses which assume a linear soil stiffness.

Jan 1, 2006

By N. Magdalinovic

Generally speaking, erosion, as a process which entails degradation of surface layers of earth under the influence of the mechanical energy of surface waters, and from the point of view of biosphere sustainability, is a harmful process. This is absolutely true when agricultural and forest areas are concerned. However, if erosion is viewed selectively, this general definition about its harm raises serious questions. In other words, the erosion which takes place in the terrains where there is no vegetation because of the geological composition of the soil, does no harm. On the contrary, if the mineralogical composition of such terrains is characterized by a presence of precious and rare metals, erosion can be very useful. It contributes to the creation of new alluvial deposits of these metals in the waters in the plain land. It is here that torrents from hills come down and cause erosion. And finally, if there were no erosion, there would be no renewable deposits of gravel and sand.

Jan 1, 2007

By M. E. Coleman, G. Money

Pneumatic Conveying and Process Injection Technologies have been implemented in the metals markets for the last 40 years and have considerably improved the productivity and the performance of many processes. There have been many steps forward in handling technology and this paper seeks to consider those now offered by Clyde Materials Handling who as an established customer-driven solutions provider has turned its attention to supporting the Metals Market. Clyde seeks to utilise its knowledge, expertise and technologies to transform the production processes of its customers, who operate in the ferrous and non-ferrous metals industries.

Jan 1, 2008

By T. Mudder, R. Cellan, R. Waterland, J. Whitlock, B. N. Nelson

The effectiveness of anaerobic in-situ biological treatment for the immobilization of selenium, molybdenum, and uranium in an alluvial aquifer was examined using long-term column tests. A series of organic substrate and nutrient combinations were tested to determine removal effectiveness, optimum supplement concentrations and ratios. Final column testing was conducted to determine the chemical stability of the treatment by-products/treatment compounds by dosing the columns continuously with elevated redox untreated alluvial groundwater.

Jan 1, 2002

By Nick Salisbury, Alan Howard, Scott Tunison

INTRODUCTION Geotechnical investigations for tunneling projects typically use vertical test borings and, to a lesser extent, angled borings. Horizontal drilling applications were often limited to specialty testing programs and to perform probe drilling from a tunnel boring machine (TBM) as part of production tunneling. The former often involved cumbersome setups with skid rigs and cribbing in a pilot tunnel or shaft. The latter usually was limited to generic probing for rock quality and ground water conditions with no sampling. Neither yielded continuous core at production rates suitable for design and construction planning. Conventional vertical investigations still make sense in many instances, particularly for tunnels planned beneath urban settings where truck access is convenient and where the tunnel horizon is not readily accessible via a portal or shaft. However, equipment is presently available to conduct horizontal geotechnicall investigations at reasonable production rates and cost. Advantages include continuously sampling the tunneling horizon and minimizing “access drilling” to get the zone of interest at the underground construction horizon. Horizontal boring lengths of up to approximately 800 m are considered feasible and those in the range of 150 to300 m are now routine. These capabilities make horizontal borings an attractive option to consider when looking at deep tunnels beneath ridges, especially where access is limited. Fewer drilling staging sites can also mean reduced environmental impacts when investigating tunnels proposed beneath sensitive lands such as public wilderness areas. Investment in early construction packages to develop portals for investigation access and, possibly in excavating test shafts for the same purpose should even be considered. Potential benefits in the form of achieving improved overall project costs using horizontal borings exist because of the significant additional data collected in the tunnel horizon. For this reason they should be considered during the routine cost-benefit analyses generally conducted for planning geotechnical investigations for tunneling. The authors also believe that collection of such data will reduce Geotechnical Baseline Report (GBR) conservatism and lead to lower potential for

Jan 1, 2005

By K Kongolo, M K. Kalenga

It is well known that the electrochemical precipitation of metals from aqueous solutions is conducted by the electrochemical standard potential scale. This scale indicates the order of nobility of different metals. Consequently, the standard potential scale shows the nocivity of metals when they are present as impurities in aqueous solutions containing metals. In the hydrometallurgy of cobalt, nickel and zinc are co-deposited during cobalt electrodeposition. Nickel has almost the same chemical, physical and electrochemical properties as cobalt. Furthermore, the electrochemical potential of nickel is relatively higher than that of cobalt. For this reason nickel is preferentially reduced at the cathode in the presence of cobalt. The presence of small amounts of zinc in solution leads to contamination of cobalt electro won. In spite of its lower electrochemical potential in comparison to cobalt, zinc is reduced on the cathode because of its higher hydrogen-overvoltage. But, in the hydrometallurgy of zinc, small amounts of cobalt present into solution will contaminates the zinc reduced at the cathode. This is easily explained by the fact that cobalt is more electropositive than zinc. The co-deposition mechanism of sulphur at the cathode is not yet well understood. Great attention has to be paid to the mechanism of co-deposition of sulphur during cobalt electrolysis..This work aimed to investigate the influence of some parameters on the co-deposition of nickel, zinc and sulphur during cobalt electrowinning. The following parameters have been investigated : Co2+ concentration in the electrolyte, current density and ammonium sulphate (NH4)2SO4 additions. It has been established that important nickel, zinc and sulphur co-deposition takes place at relatively low Co2+ concentration in solution. The behaviour of these elements with regard to the cathodic phenomena has been established.

Jan 1, 2005

By Frank G. Snyder

The Precambrian of Midcontinent United States includes a metamorphic belt of probable Middle Precambrian age, a belt of Keweenawan volcanics and sediments, and widespread igneous activity that extended from Iowa to Texas. Most of the present structural configuration of the Midcontinent was developed by epeirogenic movements during the Paleozoic. The dominant elements are basins and arches. Three major metallogenic provinces occur in the Midcontinent. They include the Missouri Precambrian iron ores, the Lake Superior copper ores, and the Mississippi Valley lead-zincbarite- fluorite deposits. Several large iron deposits, occurring in rhyolite and andesite host rocks, are known. Both discordant massive bodies and replacement- type bodies occur. The iron deposits are believed to have been formed during the period of igneous activity. They are essentially the same age as the volcanics and older than the granites that intrude the volcanics. The Lake Superior copper ores include two established districts, the Keweenawan district and White Pine, and the copper-nickel deposits in the Duluth gabbro. The lead-zinc-barite-fluorite deposits include four major districts, Southeast Missouri, Upper Mississippi Valley, Tri-State, and Illinois-Kentucky, and at least eight minor districts. Ore may occur in stratiform deposits and in veins. The major districts all contain stratiform deposits, but several have produced appreciable quantities of vein ore. Only vein deposits are known in some of the smaller districts. The major features of all districts can be catalogued in terms of host rocks, structural patterns of districts, types of ore-bearing structures, and mineralogical characteristics. From these features, a Mississippi Valley type ore body, in its type area, can be defined.

Jan 1, 1968

By John M. Popovich

Disposing of coal mine waste at the surface has been and continues to be a problem which has yet to be resolved within the coal mining industry. A possible solution to this problem is to return the refuse back into the operating underground mine generating the waste material. It is believed that the approach described will provide an inexpensive and pratical solution to the problem. The designed system is installed and operable at the Millers Cove Energy Company, Inc. property in Lee County, Virginia. This system limits surfact facilities to a minimum size. It incorporates state-of-the-art hydraulic transport and backfilling technology and equipment to systematically backfill areas within the active mine. It maximized the benefits of reducing treatment of coal wasts while it minimizes environmental impacts on groundwater. The system approaches the problem in a manner to maximize benefits and minimize risks. The cost of returning coal waste back underground at the Millers Cove site is estimated at $0.67 per ton of marketable coal (1982 dollars), which is slightly higher than their surface disposal cost of $0.61 per ton of marketable mat (1982 dollars). The underground disposal costs do not include cost savings that should be realized within the preparation plant and treatment facilities at the surface. Preliminary tests of the system were conducted at the surface; funding restrictions prevented an in-mine trial. Efforts should continue to demonstrate the feasibility of solving the problem of refuse disposal. The installed system and plant at Millers Cove should provide the opportunity to test an underground disposal operation. This report contains guidelines to pursue this opportunity.

Jan 1, 1986

By H. A. Wheeler

IT may surprise some of our members to learn, among the industries based on the mineral resources of the United States that of clay now ranks third, being exceeded in value of product only by pig-iron and coal. The present annual value of clay-products exceeds the value of the outputs of gold and silver, and also exceeds the combined values of copper, lead, zinc, aluminum, mercury, antimony and nickel. These facts are shown in Table I. which gives the statistics for the year 1902

Jan 1, 1905

By J. R. Martson

The arrangement of the larger furnace at the United Verde smelter, together with the boiler layout and connecting flues, is shown in Fig. 1. The important dimensions are given in the figure, and cross-sectional areas of combustion space, flues, etc., are recorded. The location and extent of the baffling in the boilers also are shown because of their importance in the interpretation of the data. Two boilers serve each reverberatory furnace. They are of the class M-26 Stirling type (rated at 713 boiler hp. each). Steam is generated at 178-lb. gage pressure at a total temperature of 528" F., from feed water at a temperature of 113" F. The feed water is condensate from turbogenerators plus make-up softened by the lime-soda process. The make-up is rather large in amount as it must match the amount of steam consumed in reciprocating blowing engines and the like, which are not served by surface condensers. As a result the boiler feed water has a hardness of 1.5 to 3.0 grains per gallon, but this results in the formation, during six months to one year of boiler operation, of scale only of "eggshell " thickness or less. The boilers are set at the same elevation as the tapping floor of the furnace, which results in the introduction of the waste-heat gases at the top of the front bank of tubes and necessitates the inversion of the usual baffling arrangements. The boilers are equipped with valve-in-the-head soot blowers, which keep most of the dust blown off the surface of the tubes, but it is necessary to supplement the soot blowers by high-pressure air lances, inserted by an attendant through side doors in the boiler setting. Deposits of coal ash and of dust from the furnace charge accumulate in the flues between the reverberatory furnaces and the boilers and this necessitates cleaning of these connecting flues by hand during the greater part of one of the three 8-hr. shifts during each 24 hr. This cleaning operation requires the opening of clean-out doors, which, of course, has some effect on the yield of steam. Revebberatory Furnace Practice The United Verde furnaces are fired with pulverized coal of sub-bituminous type of which the screen and chemical analyses are given in Table 1.

Jan 1, 1934