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By Henry P. Chandler

[Diamond, because of its extreme hardness and abrasion resistance, has an important function in precision engineering and automation. With the increasing; requirements of modern production for fine tolerances, interchange-ability, and speed, it has become even more important. In spite of the supply of other abrasive and hard materials and of ultrasonic, electrospark rued other substitute grinding, methods, world industry seams likely to absorb large quantities of diamond for industrial purposes. An increasing part of the world's needs will be supplied by manufactured diamond, which was introduced commercially by General Electric Co. in 1957. Use of diamond for glass cutting roes bark several centuries, mid diamond drilling of rock became important to the mining industry M the 1870's. Today, diamond drilling is the most extensively used method of exploring the world's ore reserves; diamond drills two also used to determined the nature of bedrock below the foundations of buildings, dams, and bridges. Diamond drill bits are now used extensively in the petroleum industry, and replacement or steel rock bits with diamond drill bits in hard rock formations has affected substantial savings.]

Jan 1, 1964

By Henry P. Chandler

[Diamond, because of its extreme hardness and abrasion resistance, has an important function in precision engineering and automation. With the increasing; requirements of modern production for fine tolerances, interchangeability, and speed, it has become even hors, important in spite of the supply of other abrasive and hard materials and of ultrasonic, electrospspark rued other substitute grinding methods world industry seems likely to absorb large quantities of diamond for industrial purposes. An increasing part of the world's needs will be supplied by manufactured diamond, which was introduced commercially by General Electric Co. in 1957. Use of diamond for glass cutting goes bark several centuries, mid diamond drilling of rock became important to the mining industry M the 1870's. Today, diamond drilling is the most extensively used method of exploring the world's ore reserves; diamond drills two also used to determine the nature of bedrock below the foundations of buildings, dams, and bridges. Diamond drill bits are now used extensively in the petroleum industry, and replacement or steel rock bits with diamond drill bits in hard rock formations has effected substantial savings.]

Jan 1, 1964

By Irving Hartmann, F. P. Christofel, John Nagy, E. B. McGibbeny

"INTRODUCTION When permissible explosives are used in c procedure recommended by the Bureau of Mines 5/ they are relatively safe, and, no mine explosions are known to have resulted from this type of blasting. However, unsafe blasting practices - the use of nonpermissible explosives or the improper use of permissible explosives - have caused many serious disasters. In fact, such unsafe practices constitute the third most important cause (exceeded only by electricity and the use of open lights and smoking) of coal-mine explosions in the United States. During 1929-1947, inclusive, 81 explosions, resulting in 475 fatalities, were ascribed to unsafe blasting. 6/The hazards of black powder, dynamite, and other nonpermissible explosives in coal mines have been recognized for many years, and attention has been called to this in numerous Bureau of Mines publications. Not only can these explosives ignite flammable gas-air mixtures readily, but they can also ignite coal dust, as has been illustrated repeatedly in tests and at educational public demonstrations at Bruceton and elsewhere. 7/Research in the Experimental coal mine 8/ of the Bureau of Mines at Bruceton, Pa., and unfortunate experience in commercial mines have proved beyond doubt that improper use of explosives that have passed the official permissibility tests can cause as explosions. In limited tests with a fey American permissibles at Bruceton, and in more, extensive tests with permitted explosives at the Polish experiment station, 9/ explosive charges were fired from steel cannon and freely suspended in coal-dust clouds. In these experiments coal dust was ignited under some conditions. However, it has never been definitely established whether permissible explosives can initiate coal-dust explosions when fired in a coal seam. It is true that a few mine explosions were strongly suspected to have resulted from ignition of coal dust by misuse of permissibles, but in each case other complicating factors introduced some doubt in the minds of the investigators. Full knowledge of the problem is important, because coal dust is present in most blasting operations in coal."

Apr 1, 1952

By Z. T. Bieniawski, Benjamín Celada

After emphasizing the importance of quantitative rock mass classifications in mining, originally directed to selection of rock support measures, but subsequently to estimates of rock mass properties such as rock mass strength and rock mass modulus of deformation, current attention calls for a classification specifically for rock mass excavability by tunnel boring machines (TBMs), which are used extensively in tunneling as well as in the mining industry. This paper introduces the Rock Mass Excavability (RME) index for predicting excavability of rock masses by TBMs using a quantification of machine performance and rock mass conditions. The RME index is based on five input parameters aimed at relating rock mass behavior and machine characteristics: (1) uniaxial compressive strength of the rock material, (2) drillability/abrasivity, (3) rock mass jointing at mine drift face, (4) standup time of the excavation, and (5) groundwater inflow. Development of the RME index entailed the collection of extensive data from more than 28 km of tunnels and some 400 case records from projects in Spain involving double-shield TBMs. In the process, a number of statistical correlations have been established between RME and such output parameters as degree of machine utilization, advance and penetration rates, thrust and torque of the cutterhead, and the specific energy of excavation. It was found that the RME index provides a particularly significant correlation for predicting the average rate of advance (m/day). In essence, the RME index is a classification system that features interaction of rock mass conditions with boring machine characteristics for use in the early stages of a project. It should be noted that the RME index does not replace the Rock Mass Rating (RMR) or Q-systems as used in mining and tunneling; indeed, one of the RME input parameters, standup time, is determined from the RMR. However, the approach presented introduces a specialized tool relevant to excavating tunnels and drifts. Possible applications to hard-rock mining are explored.

Jan 5, 2007

By Collin L. Stewart

The high cost and limited flexibility of modern longwall systems has resulted in the need for mine engineers and geologists to predict possible adverse mining areas ahead of mining and to then design and implement suitable ground control solutions in a timely and cost effective manner. Therefore, over the last 30 years, geo-technical evaluations for coal mine planning and development have advanced from a minor afterthought to an important part of today?s successful, high capacity, longwall mining operations. The latest iteration in this progression of improved analysis for predicting future mining conditions is a computer-based Stability Mapping System developed by West Virginia University. This system is designed to allow the mining engineer and geologist to effectively combine the mine geologic characteristics, stress influences, and structural features into an integrated stability map for use in mine planning and support design. This paper details the application of the stability mapping system to Bowie Resources, LLC, Bowie No. 3, multiple-seam longwall coal mine. At this mine, the prediction of adverse mining conditions using the stability mapping system allowed management to accurately adjust their support densities and operational procedures, and to successfully mine through difficult conditions safely and successfully.

Jan 1, 2006

By Jian Wu

In this paper, the surrounding rocks and the supports in a longwall are taken as an integral, i.e. a system. The structural characteristics and behavior of the system are discussed based on in-situ observations. A set of equations, which describe the interaction among the support, immediate roof and main roof, are developed. These equations can be used to design the longwall powered supports more reasonably and economically.

Jan 1, 1989

For the past four years, the Department of Mining Engineering at the University of Kentucky has conducted a validation study of the CFD Fluent code, by comparing its results against mining-related benchmark experimental data provided by NIOSH?s Pittsburgh Research Laboratory. This particular study is dedicated to the effect of machine-mounted dust scrubbers on the performance of face ventilation systems using extended-cut mining with a blowing curtain.

Jan 1, 2009

By John R. Reynolds

This paper describes mining and milling methods of the American Smelting & Refining Co. at the Morning mine in the Mullan area of the Coeur d'Alene mining region in Idaho and is one of a series of Bureau of Mines reports dealing with methods and costs of mining throughout the United States. The Morning mine has been described previously in a Bureau of Mines report published in 1930,2/ and the milling methods and costs at the Morning concentrator were presented in a Bureau of Mines report published in 1932. 3/ These reports are supplemented by this publication, which presents data to show the effect of changing times and conditions on a typical medium-size mining operation during the latter part of its history, when costs were rising and production was from increasingly greater depths. The report contrasts two periods in the history of the mine-periods not too far separated in years but considerably different in economic conditions. During the first period (1939) costs of labor and materials were moderate, mining operations were just being transferred from the main shaft to deeper workings opened from the offset shaft, and the operation prospered. During the second period (12 years later) production costs had increased following the national trend in all industry, mining was from greater depths near the bottom of the ore body, and the operation was becoming unprofitable. Mining on the lower levels of the property ceased in 1953.

Jan 1, 1956

By W. Vorster

Bateman Engineering Project's acid-plant track record goes back to 1977. Bateman Engineering can design sulphuric plants based on gas from sulphur burners, metallurgical off gas as well as pyrite roasting systems. Bateman Engineering has a technology marketing agreement with NORAM Engineering Ltd of Canada to provide state-of-the-art, well-proven acid plant technology, and also has access to roaster technology from several sources, including Chinese technology. Utilising the Noram technology agreement, Bateman was awarded the Engineering and Procurement (EP) contract for the Ambatovy Nickel Project, Sulphuric Acid Facilities in 2007. This is the first Greenfield sulphuric acid plant Bateman has designed for many years, producing a combined 5,500tpd, and is one of the largest sulphur burning acid plants in the world. This paper gives an overview of the sulphuric acid plant for the Ambatovy Nickel Project, advantages of Noram?s unique technology on offer, an overview of work conducted on a recent study of an pyrite roasting acid plants as well as a new technology currently being developed by Bateman for the direct combustion of solid sulphur to form sulphur dioxide.

Jan 1, 2009

Jan 1, 1963

By G T. Kukla

A Seam deposit User oriented Mine Planning System (SUMPS) was developed by The Broken Hill Proprietary Company Limited (BHP) at its head office in Melbourne. It is one of the computer mine planning systems developed by the Corporate Data Processing (CDP) section of BHP. To date it has been employed in the feasibility study of four coal prospects for the BHP Group, including Gregory in central Queensland û Ham and Van Hoorn (1978). It was also used in detailed short term mine planning for Gregory. A recent application was in the feasibility study of Saxonvale, a multi seam coal deposit in New South Wales with seams up to 20 m thick. The other two applications of SUMPS were also on thick multi seam coal deposits. Development of programs for the underground subsection of SUMPS is continuing. SUMPS was developed and implemented on mini computers with graphics and plotting peripherals. The company's philosophy towards computing is one of centralized development and project planning, with transfer of hardware and software to site once the mine becomes operational. Support of the site's system continues from head office which is continually involved in development of SUMPS and issuing revision updates to sites. The users, as well as programmers, were mostly geologists and mining engineers. This helped to ensure rapid, successful implementation. The broad approach of this system was to use interactively the specialist skills and interpretative abilities of the user mining engineers and geologists with the data manipulation abilities of the computer. It is an integrated system which covers geological exploration, deposit modelling, mine planning and production scheduling. An important feature of the system is that the user has full interactive control over each function through a graphics terminal where applicable.

Jan 1, 1980

By M. H. Solomon

After the global financial crisis of 2008, African mining is entering anew phase of development. The rapid withdrawal of emerging market funding from the critical exploration and development industries provided a hiatus in funding, a gap which was quickly filled by Chinese and other Asian investors. While the continent is still economically dependent on its extractive industries, the prevalence of Dutch Disease has undermined Africa?s ability to benefit fully from its mining, oil, and gas industries. While the extractive industries are closely related to many of the more fragile and failed states in Africa, it is equally true that the strongest states in Africa have mining-based economies. This paper explores the possible linkages between mining, strong and weak political economies, and poverty in Africa. It draws the conclusion that neither Dutch Disease nor Resource Course is a given in resource-endowed countries, and that it can be avoided if the mining economies in these countries are actively integrated into their respective broader economies and used to foster economic diversification. The author asserts that given the capacity constraints of many African governments, it is contingent on mining companies to become integrally involved in catalysing diversification around their infrastructure and supply chains.

Jan 1, 2011

By Donald O. Capstick

The U.S. Bureau of Mines conducted an inventory of the prospects and mineral resources in the Scodies RARE II area (No. 5212) in 1982. No mineral production is recorded from the area, and no mines are being developed. The Scodies RARE II area is comprised primarily of light colored granodiorite with minor inclusions of mafic granitic rocks. Late stage differentiates of magmas resulted in quartz veins and pods. Metasedimentary rocks which have been mineralized in some parts of the Sierra Nevada were not observed within the study area during this investigation but small inclusions have been reported.

Jan 1, 1983

By S. R. B. Cooke, H. S. Choi, I. Iwasaki

In a previous article1 the function of various fatty acids as collectors for iron ores was reported for the two alternate processes; (a) the flotation of iron-oxide minerals, and (b) the flotation of calcium-activated siliceous gangue. The selectivity of separation was shown to be markedly dependent not only on such common parameters as pH and the levels of collector and activator addition, but also on the structure and the degree of unsaturation of the acids used. The iron ores employed consisted primarily of hematite, goethite, and quartz and as the effectiveness of any one acid on the separation depends on the individual response of each constituent mineral toward the given collector, a comprehensive knowledge of the floatability of the individual minerals is desirable for the interpretation of the results obtained. The mechanism by which a collector ion becomes attached to a mineral-solution interface has been a subject of much investigation. From quantitative studies of the properties of the electrical double layer on mercury2 and on several solid surfaces3,4,5,6 , the adsorption of some flotation reagents at the mineral-solution interface is beginning to be understood. For example, it has been demonstrated from streaming potential measurements made on quartz5 and corundum6 that the interfacial electrical condition is strongly dependent on the pH. Thisoccurs presumably through the following electrolytic reaction at the interface, and in the presence of a flotation collector, controls the floatability of the solids. A concurrent investigation of the flotation behavior of goethite and of quartz carried out at the School of Mines and Metallurgy7 has shown a positive correlation with the electrokinetic behavior of these minerals. The purpose of the present investigation was to collect general information on the floatability of hematite, and to investigate the function of various 18-carbon aliphatic acids on the floatability of hematite, goethite, and of activated quartz. Electrophoretic mobility measurements, simplified flotation tests using a modified Hallimond tube, and contact angle and frothability measurements were employed. The results are of direct application in the interpretation of the batch flotation results on natural ores as

Jan 1, 1961

By W. Vorster

Bateman Engineering Project's acid-plant track record goes back to 1977. Bateman Engineering can design sulphuric plants based on gas from sulphur burners, metallurgical off gas as well as pyrite roasting systems. Bateman Engineering has a technology marketing agreement with NORAM Engineering Ltd of Canada to provide state-of-the-art, well-proven acid plant technology, and also has access to roaster technology from several sources, including Chinese technology. Utilising the Noram technology agreement, Bateman was awarded the Engineering and Procurement (EP) contract for the Ambatovy Nickel Project, Sulphuric Acid Facilities in 2007. This is the first Greenfield sulphuric acid plant Bateman has designed for many years, producing a combined 5,500tpd, and is one of the largest sulphur burning acid plants in the world. This paper gives an overview of the sulphuric acid plant for the Ambatovy Nickel Project, advantages of Noram?s unique technology on offer, an overview of work conducted on a recent study of an pyrite roasting acid plants as well as a new technology currently being developed by Bateman for the direct combustion of solid sulphur to form sulphur dioxide.

Jan 1, 2009

By Samuel J. Kosa

The Monotube is a uniformly tapered high-strength steel shell pile manufactured for friction pile applications. The Monotube pile was developed in the early 1920's in Canton, Ohio. Its first commercial installation was an Ohio railroad trestle in 1926. The Monotube has been manufactured in the same Canton plant since its inception. The Monotube is produced in four diameters, 12, 14, 16 and 18 inches, with U. S. Standard Gage wall thicknesses of 9, 7, 5 and 3. The uniformly tapered Monotube section can be manufactured in one of three rates of taper.

Jan 1, 1993

By V. D. Jalevsky

A new methodology of an experimental-analytical approach has been developed. It is used in building an information geomechanic monitoring system for the modeling of geomechanic processes during coal seam working. The approach synthesizes experimental (in-situ) measurements of rock pressure manifestation in separate points, methods of numerical modeling of processes on rock boundaries with coal, and a seam analytical calculation of rock mass in a spatial strained state. One of the realizations of this approach is the developed theory and calculation method of adjoining rock surface shift (overhang) formation during underground working of sheet deposits and of rock mass geomechanic state determination. There are description algorithms of cavity configurations with broken lengths of faces during underground working of useful mineral sheet deposits. These algorithms have been used in computer modeling of formations of adjoining rock surface overhangs and abutment pressure upon rock mass in the area of coal faces with irrectilinear longwalls. Peculiarities of surfaces shifts and stress allocation are established for different face schemes. The use of theory and methods alloww working out techniques of automatic control to receive processing algorithms of RPM measurement results and calculate geomechanic situations within panels in the process of planning and development as well as during mining, i.e., to carry out long-term prediction, in-line control, and short-term prediction of rock pressure manifestations.

Jan 1, 1996

By M. Bennett, L. Twidwell

Montana Tech has embarked on a coordinated series of studies to delineate the characteristics of the Berkeley Pitlake containing over 36 billion gallons of acidic, metal-contaminated water formed after the cessation of open-pit copper mining in Butte, Montana, USA. The objectives of the overall series of studies are to summarize presently available information and to generate new and needed information to formulate a conceptual environmental model for the pitlake and to provide characterization data for the development of advanced treatment technologies. In this presentation, the chemistry of the Berkeley Pitlake water is partially reviewed. It is known that the pitlake consists of two distinct layers of water referred to as surface and deep water. Samples of deep water were collected and placed in a 12-ft high and 6-inch diameter column and exposed to different wavelengths of UV radiation as well as atmospheric conditions. Measurements of pH, redox potential (EH), dissolved O2, turbidity, conductivity, temperature, and elemental composition show that the water reacts differently and indicates that the diurnal effects of sunlight likely play a major non-biological role in its chemistry. Resulting technology could be useful for developing an alternative to treating acid-rock drainage.

Jan 1, 2007

By R. Hipsley, D. Arbonies, P. Dobak

South Arturo is a “Carlin-type”, breccia-hosted, oxide gold deposit located at the north end of the Carlin Trend. The discovery hole was drilled in July 2005 from mine dumps 1,000 feet south of the Dee open pit. Discovery hole (BD-72) encountered a cumulative 245 feet @ 0.056 opt Au beneath 850 feet of post mineral Tertiary Carlin Formation. Oxidation extends to depths greater than 2,000 feet in the deposit area. The deposit is presently in definition drilling stage with approximately 190,000 feet of drilling completed to date. A resource estimate is in progress. This paper will focus on the discovery and descriptive characteristics of the mineralization.

Jan 1, 2007

By Christopher C. Woomer

Cyprus Shoshone Mine uses the longwall method to extract a deep, thick, pitching coal seam in the Hanna Basin of South Central Wyoming. The immediate, and main roof rock consists of weak, thinly-bedded, silty mudstones with weak, interbedded fine-to medium-grained sandstone. Tailgate ground control has been a critical factor impacting productivity at the mine. A gateroad condition mapping program for the 11 left longwall gateroads indicated potentially severe ground control problems for the tailgate. It was predicted that the existing, secondary support pattern of wood cribs would not provide adequate support capacity. As predicted, severe deterioration of the tailgate occurred in the form of a roof cutter, sloughing ribs, and failing wood cribs. Productivity was affected and additional support was required. Shoshone personnel evaluated several options for providing the additional support needed in the tailgate. The additional support system and placement method had to satisfy several requirements with respect to access, materials handling, placement method, set-up time and support capacity. Approximately 6,000-ft. of deteriorating tailgate had to be supported. The initial wood crib support system left a 6-ft. walkway for access and construction of the additional support. This access was further reduced as the roof loaded the wood cribs. This eliminated the possibility of mechanized material handling to the construction locations. All materials would have to be transported by hand. The additional support system had to be placed quickly to stay ahead of, and keep pace with, the required longwall advance rate. It had to incorporate the existing wood cribs and provide at least 500 tons of extra support capacity. And most critically, the system could not affect longwall ventilation. Longwall coordinators and engineers made the decision to use a low density, pumpable cement known to the industry as TeksealTM, to provide the system required. A 200 psi ultimate strength mix was decided on to provide the required load capacity. The existing cribs were formed with 1-in. by 6-in. boards and brattice cloth to provide the containment. To overcome the access limitations, three boreholes were drilled from the surface to the tailgate on 2,000-ft centers. A mobile pumping station was established on the surface and the TeksealTM was pumped 900-ft. down the boreholes through a 1.5-in. steel pipe, then as much as 1,800- ft. along the tailgate entry through 1.25-in. miner spray hose. The materials required for the TeksealTM supports could all be carried into the construction locations by hand. As a direct result of incorporating relatively new methods of pumping high yield, low density, cementitious grouts, the Shoshone Mine reduced downtime due to tailgate ground control problems by approximately 70% in comparison with previous Longwall panels. The longwall set three monthly production records while mining the 11 left longwall under the deepest cover, steepest pitch, and most extreme ground control conditions ever encountered at the mine.

Jan 1, 1995