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By Heather Wright

Shovel operators are one step closer to having a better tool to operate and monitor their equipment. The development of a unified shovel interface is proceeding into phase three, focused on producing a standard application programming interface (API) for connecting onboard devices. This solution will positively impact safety, performance and productivity, and is the result of collaborative work driven by the Global Mining Standards and Guidelines Group (GMSG). Proof of concept revealed During the spring of 2013, Peck Tech Consulting was engaged to develop the working proof of concept (POC) software implementation, which integrates multiple vendors? systems into a single interface using one-to-two displays. As a result, the GMSG developed a functioning, manipulatable, unified shovel interface proof of concept and unveiled it at the World Mining Conference in August in Montreal. The proof of concept effectively provides a unified operator interface that pulls together the many divergent systems onboard large shovels.

Mar 1, 2014

By Sherwin Kelly

THE need for geophysicists to adopt a uniform mode of expressing the electrical resistivity of geological formations has been stressed by Dr. A. S. Eve.1 The present paper is to emphasize the point he raised, to bring the weight of disinterested authority to bear on the matter, and to urge the adoption henceforth, save in exceptional cases, of a standard expression for resistivity; all in the hope that the needed reform will thus actually be brought about. The general definition of the resistivity of a material is the resistance in ohms between two opposite faces of a unit cube of that, material. No account need be taken here of the cases in which the unit volume is not a cube, and the units of length and cross-section are different, encountered principally when dealing with metallic conductors such as wires. The idea of the resistance of a unit volume of earth or rock has found expres-sion in geophysical literature in a number of forms and with a variety of units. Fortunately, the metric system has been adhered to in most cases, so ordinarily the meter or the centimeter, usually the latter, has been the measure chosen. The resistivity is then the resistance of a cube of the given rock, or soil, one centimeter on, an edge. This is far from always being the same thing, however, as the resistance of a cubic centimeter. A long thin wire could contain a cubic centimeter and have a high resistance, whereas the same volume formed into a flat plate would have an entirely different, and quite low, resistance between faces. Con-sequently, it is not proper to express resistivity in ohms per cubic centi-meter, inch, etc., as has been done occasionally by .some writers. In an effort to emphasize the idea of cubic volume, some geophysicists, the writer among them, have used the phrase, ohms per centimeter cubed. This is a graphic way of picturing the measure, but is not in favor among highly qualified authorities. In this connection, an appeal was made to the U. S. Bureau of Standards for advice, and the Director, George K. Burgess, kindly replied in detail as to the practice adopted by his Bureau: ." . .' such expressions as ohms per centimeter cubed' or any similar expressions are objectionable, because they certainly carry the implica-tion that the resistivity is found by dividing ohms resistance by the volume in cubic centimeters." Actually, of course, resistivity is found

Jan 1, 1932

By John Randall

IT is a fair assumption that the main purpose of any diagram is to present facts to the eye in more convenient form than they could be tabulated in figures, and this implies that a screen diagram should set forth in a convenient and familiar form certain facts as to the character of the material screened regardless. of the screen standards used, and it seems particularly desirable on account of the well-known differences in the size of openings of different laboratory screens having the same nominal mesh. In making screen-sizing tests it has been customary to first consider the largest size, going progressively to the smallest, and this seems to have led to the practice of placing the smallest size at the right-hand side of the diagram and .measuring toward the left. This is not altogether convenient and might he changed to advantage, but for illustration I have preserved that feature and present the method just as I have used it for over 2 years. Direct plotting in which the intervals on the diagram are proportional to the sizes of the openings, or to the arithmetical difference between them, seems at first sight more natural and is extremely useful for certain purposes, but it makes the diagram very crowded in the smaller screen sizes while the larger ones occupy unnecessary space, snaking it less convenient for most purposes, and for that reason the method here discussed is the well-known one based oil the ratio between openings, and is plotted in logarithms instead of the direct values of the screen opening. Metric coordinate paper is convenient, although .not necessary; it is recommended, as the use of the metric scale gives a diagram of convenient size, but any scale of equal. parts may be used. In order to make any screen diagram translatable in terms of any standard screen size, it is necessary to have rioted on the size scale of the diagram all points corresponding to the openings of the various screens in question, instead of a single series 'of points as with a single screen. In drawing the diagram assume 0.001 in. (corresponding approximately to 0.025 mm.) to be the smallest size to be considered and fix this as the zero point at the lower right-hand corner of the diagram. This value is selected because the values are to be plotted in logarithms, and the logarithm of 1 is zero. Then lay off to the left for the position of each screen

Jan 9, 1917

By Y. S. Kim, A. Bailey

A feasibility seismic refraction and reflection field survey was conducted at the U. S. Borax Company open-pit mine, Boron, California by the writers during the weekend of March 13 and 14, 1976. This field survey was carried out as a preliminary investigation primarily for the purpose of evaluating and establishing the ability of such geophysical techniques to locate and outline the subsurface openings of the old room-and-pillar mining under the present open-pit. The value of such knowledge about the old underground workings is directly related to the safe and economical operation of the open-pit mine for the company. Although mine maps of the old underground workings are available at the mine, the extent of roof and wall cavings and the present condition of the old underground openings are unknown. Owen and Suhler (2) are the first investigators who used electromagnetic methods, Pulse-Echo System, and electric resistivity measurement to solve the problem without success. A few years later, Herzig and Owen (1) attempted to solve the problem with application of earth resistivity measurement method with unfavorable results. The U. S. Borax Company carried out an extensive study for slope failure problems of the open-pit with application of dipmeter measurements. However, the slope stability study was not correlated to the old underground openings lying under the present open-pit (3).

Jan 1, 1977

By K. Biswas

In general, it cannot be assumed that the strength of coal pillars remains constant over long time periods. Field observations indicate that a coal seam, especially when it contains a parting layer, deteriorates over time, reducing load-bearing capacity of the pillars. This paper discusses a unique approach to determine the time dependent strength of coal pillars in the field. Three coal pillars that were developed 5, 15 and 50 years ago were chosen for the study. Holes were drilled in coal and parting layers in each pillar and the strength profiles were determined for each hole using the Borehole Penetrometer. The strength data were treated statistically to establish time dependent strength equations for different layers. The results can be used to help estimate the loss of pillar capacity over time.

Jan 1, 1999

In general, it cannot be assumed that the strength of coal pillars remains constant over long periods of time. Field observations indicate that a coal seam, especially when it contains a parting layer, deteriorates over time, reducing the load-bearing capacity of the pillars. This paper discusses a unique approach to determining the time-dependent strength of coal pillars in the field. Three coal pillars that were developed 5, 15, and 50 years ago were chosen for the study. Holes were drilled in coal and parting layers in each pillar, and the strength profiles were determined for each hole using a borehole penetrometer. The strength data were treated statistically to establish time-dependent strength equations for different layers. The results can be used to help estimate the loss of pillar capacity over time.

Jan 1, 2012

By C. DeWitt Smith

"It just looks like everything is doing fine but humans," wrote Will Rogers fifty years ago. "Animals are having a great year, grass was never higher, flowers were never more in bloom, trees are throwing out an abundance of shade for us to loaf under. Everything the Lord has a hand in is going great, but the minute you notice anything that is in any way under the supervision of man, why, it's cockeyed." Do these words from two generations ago apply to oil shale? The United States has been blessed with deposits that can yield synthetic crude oil at a cost competitive with natural crude oil-under present economic conditions and with existing technology. Yet, the oil shale program is cockeyed because of the artificial obstacles that have been placed in its path "under the supervision of man." But more about this later. For the moment, let's focus on...

Jan 10, 1974

By George L. Baloo, Dave Kwiatkowski, Jose G. Cañlzales

Capital project funding for a medium to large materials handling project often includes a budget for procurement of supplier-recommended spare parts, and it is the Project Team's responsibility to select these parts. With today's economic climate, limited budget, and other factors, the spare parts selection process is a difficult and arduous effort. This decision carries with it a risk to plant operations and in some cases the commodities producers. Too often the decision-making process is not documented, and the reasons for eliminating and reducing quantities are based on "best guess " Recently on the Solids Handling Phase 2 Project in Jose, Venezuela, the Project Team took a unique approach to this problem. This paper discusses the analytical approach taken by the Project Team, the database system that was developed to manage this problem, lessons learned, and their applicability to pre- project planning and preliminary design.

Jan 1, 2004

By George F. Swindle

This paper discusses a composite of two coal reserve studies, each of which made use of a computer-based modeling system to assist in an evaluation of multi-seam deposits. The model permitted simultaneous consideration of seam thickness, seam structure, overburden thickness, over-burden ratio, and quality parameters for sulphur content, ash content, BTU values and the EPA Compliance index. The model is designed for use by a non-programmer, geologist or mining engineer. It enables the user, from a computer terminal in his office, to specify constraints (for example maximum um sulphur and maximum- ash content, minimum seam thickness and minimum BTU rating), and produces a report showing the volume, quality and location of that part of the total in place deposit satisfying all the constraints.

Jan 1, 1983

By Nic Arrieta

The Arimetco White Cliff Diatomite operation near Tucson, Arizona will be discussed and reviewed across the spectrum of geology, mineralogy, mining, processing and product attributes and market applications. Unique for the operation are the type, quality and the extent of the reserves and several product characteristics of the diatomite.

Jan 1, 1996

By Paul J. Cascone

This paper will discuss the science behind the development of a unique gold alloy for dental prosthetic applications. The alloy (GOLDTECH BIO2000) contains 99.7% gold providing unquestioned biocompatibility and unsurpassed esthetics. The topics discussed are: (1) How the alloy meets the functional requirements of a porcelain-fused-to-metal dental alloy. (2) How the alloy color affects the esthetics of the restoration and why the color of gold is best. (3) Overcoming the intrinsic malleability of gold when grinding the alloy surface. (4) Preventing the oxide color from interfering with the alloy esthetics. (5) Attaining excellent porcelain adhesion. (6) How the design of the restoration allows for the production of single and multiple unit restorations. Gold 2003

Oct 1, 2003

By G. R. W. Walker

A unique means of obtaining sea-water by G. R. W. WALKER, Pr. Eng., B.Sc. (Hons.) (Min. Eng.) (Member) Although the mining and treatment operations at The Consolidated Diamond Mines of South West Africa, Limited, are located within an average distance of I km from the Atlantic Ocean, the supply of clear sea-water in large and continuous quantities for use in treatment plants is made difficult by siltation of water-holes and the amount of sand in suspension in the sea itself. The need for sixty million litres of sea-water per day at the new No. 2 treatment plant necessitated the construction of a system that would ensure a continuous and reliable supply. Several sea-water intake schemes were proposed. This paper outlines the need for an improved means of obtaining water and describes the construction of the scheme eventually chosen - a tunnel driven through bedrock for over 400 m beneath the Atlantic Ocean. At the end of the tunnel, two large chambers were excavated from which vertical holes were drilled to intersect the sea-bed.

Jan 5, 1976

NANA Accepts Mining ­ 1974 - Leadership presented mining option to people ­ Community meetings; recognized need for cash economy ­ 1979 - Poll shows consensus in favor of mine development ­ 1980 - Shareholders approve mining; Congress approved land selections

May 1, 2002

By Anthony Anable

HOOVER DAM, rapidly nearing completion in the Black Canyon of the Colorado River at Boulder City, Nev., taxes the superlatives of the vocabulary to describe. For by all odds, it is the largest construction project of its type ever essayed by man and the plants providing the essential materials of construction are also in a class by themselves not only in size but in advanced design, mechanization, and accurate control. Picture, if you will, the great aggregate plant, as it is called, situated about 4 mi. upstream from the site of

Jan 1, 1934

By Jesús E. Gómez

In the Summer of 2011, emergency repairs to the Jefferson Memorial North Plaza and Seawall were completed. These repairs were necessitated by settlement and lateral movement of the seawall and North Plaza which prompted the National Park Service (NPS) to initiate an investigation as to the possible causes of the movement, and commission a design for its mitigation. Information gathered from extensive instrumentation on site led to the design of a movement mitigation scheme that included demolition of the Ashlar Seawall and reconstruction of a new seawall. The new seawall foundation is an A-Wall consisting of vertical caissons and battered pipe piles connected to the seawall itself. The scheme provides resistance to future vertical and lateral movement of the North Plaza and the new seawall. Repair to the seawall and plaza began in December 2009, and was completed in August 2011. This paper discusses the mechanisms believed to be responsible for settlement and lateral movement, summarizes the procedure followed for design of the mitigation, and describes the construction methods and some challenges faced during the repair.

Jan 1, 2011

By Dawson CF

About 17% of the world's present day oil supplies comes from wells drilled in the continental shelf of some 28 countries. The demand for oil is increasing each year and is expected to quintuple in the next decade. In the same period, the demand for gas will climb to at least 20 times its present rate. In the next decade, the percentage of oil and gas obtained from offshore is expected to rise to nearly half the world's consumption. The offshore oil industry is currently striving to achieve new technological advances in the field of deep ocean operations, especially in face of adverse seas. While the emphasis was put on drilling vessels for exploration, the industry was slow in developing effective offshore construction vessels. Until a year ago, construction vessels were but large barges with construction equipment mounted on their decks. These vessels all shared the same severe limitation: When the sea exceeds a five-foot wave height (and in some cases as little as three feet) the conventional construction barge is forced to suspend operations. In face of an oncoming storm they must run for shelter. Their utilization, therefore, is limited and in rough weather areas, such as the North Sea or the Bass Strait is lower than 50%.

Jan 1, 1970

By Thomas E. Krakowski

INTRODUCTION This paper presents a method of calculation of internal moments and thrusts in tunnel liners of any material. The method is intended for hand calculation, but as it is numerical in nature it can be programmed for use in computers. The information required for design or analysis is presumed active internal and external pressures, the effective moment of inertia and cross-sectional area of the tunnel liner, the liner's modulus of elasticity, and the coefficient of subgrade reaction of the material surrounding the tunnel. Starting with active external and internal pressures and following the procedure described herein using the structural properties of the liner and surrounding medium, external passive reactions and internal moments and thrusts are calculated. The method is intended for use by design engineers. GENERAL Experience has shown that flexible tunnel liners have less internal bending stresses than those calculated using classical structural theory applied to free-standing arches. In fact, liners which are very flexible in relation to the surrounding soil or rock have virtually no bending moments when compared to free-standing arches supporting equal active loads. In order for this phenomenon to occur, the original active pressure diagram must be "modified" by additional external reactions (passive pressures) from the surrounding material, so that the thrust line within the lining follows the centroid of the tunnel arch more closely than that of a similar free-standing arch. These passive pressures are reactions developed through outward deflection of the tunnel liner. Thus, the outward moving portions of a

Jan 1, 1979

By R. P. King

The University of the Witwatersrand (Wits) and the minerals industry of South Africa have grown with the city of Johannesburg. The former has provided teaching and research in mining and metallurgy, while the latter has been responsible for the practical training of metallurgists and for the testing and implementation of innovative ideas proposed by the academics. This interplay between inventiveness and industrial application is illustrated by three examples: the establishment of the iron and steel industry as a result of the persistent experimentation undertaken by Professor G. H. Stanley, the first Professor of Metallurgy and Assaying at the South African School of Mines, which later became Wits; the establishment of the research organization that eventually became the Council for Mineral Technology (Mintek) - again through Professor Stanley's faith in the role of research; and the establishment at Wits of physical metallurgy as a discipline in its own right, as first suggested by Professor C. E. Mavrocordatos of Wits against the opinion of his colleagues in the industry. The Department of Metallurgy at Wits has been well supported by the minerals industry. Not only does the industry provide grants for the financial support of students, but it supplements the salaries of personnel in the Department, making possible the recruitment of top-class academic staff. At present the greatest problem is the lack of interest shown by matriculants in the metallurgical industry as a career. However, an enormous effort is being made by the Chamber of Mines, The South African Institute of Mining and Metallurgy, and the Wits Department of Metallurgy to ensure that matriculants receive appropriate information about the career prospects in the minerals industry.

Jan 1, 1983

By Geo. H. Ashley

THE present critical state of the supply, distribution, and utilization. of coal and the necessity for pooling and zoning coals calls renewed attention to the lack of any fully adequate classification of coal. In the past coals have been classified as anthracite, semianthracite, semibituminous, bituminous, subbituminous coals, and lignite, and a few special types, such as splint coal and cannel coal. But under the term bitumi¬nous coal are included a great variety of coals differing markedly both physically and chemically. The term subbituminous coal covers as great a range of chemical differences. In order to distinguish these varieties of bituminous coals it has been customary to designate coals by names derived from the place where mined, or by the name of the bed from which it is mined. Thus, in the market reports, coals are quoted as Pocahontas coal, New River or Sewell coal, Moshannon coal, Ohio coal, Williamson County coal, Jellico coal, and so on indefinitely, no limit being set as to the boundaries of the area to which a given name is applied. Nor is there any scale by, which the coal from one place may be compared with the coal from some other district or some other bed. On the one hand, coals from the same district may be quite distinct and sell at very different prices or coal from the same bed may differ greatly in different districts; on the other hand, coals from different states may be so similar physically and chemically that one could replace the other in practical use without any appreciable difference in service.

Jan 8, 1919

By T. MacDONALD

ATHOUGH flotation has been a commercial process for over twenty years, the last two years have witnessed a sudden and phenomenal increase in our knowledge of how to separate minerals heretofore not considered amenable to flotation at all. As remarked by Professor Locke in the January issue. "Either commercial or laboratory flotation is reported on zircon, ilmenite, carnotite, kyanite, scheelite, chromite, fluorite, feldspar, cassiterite, wolframite, barite, and clay. Attractive patents on soap flotation are U. S. Nos. 2,000,656 and 2,040.187. A survey by Ralston in the February E. & M. J. adds many other minerals to this impressive list. The simple but pregnant fact is that any mineral can be coated, directly or indirectly, with a water-repellent coating, and since this is true, it follows that any mineral can be floated. Fundamentally, this is no new discovery, where, for instance, is the mineral that cannot he washed from a pair of dirty hands by means of soap and water, given the absence of refractory greases or oils which would have no proper place in flotation ?

Jan 1, 1937