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By W. E. Segsworth

Introduction By far the largest part of the money raised for mining is raised by honest and legitimate means; but a not inconsiderable amount is raised by fraudulent sales methods. It will be conceded without argument that the greatest menace to the mining business is the fraudulent promoter. The sale of worthless mining stocks to the public by high-pressure. salesmen, house to house canvassers, telephone campaigns, fraudulent use of the mails, fraudulent statements, and reloading, has seriously prejudiced the public against even legitimate mining. A very small percentage of the funds raised by such fraudulent means is ever spent on the property, but instead is absorbed by the promoter in illegitimate' profits, enormous commissions, high office rents, and other expenditures, and is just so much subtracted from the fund which the legitimate developer needs to bring new mines to the point of production. The mining fraternity has been at fault in that, while they recognized this situation, they made no adequate attempt to rectify it. They knew that these fraudulent practises were conducted by parasites who attached themselves to the mining business in boom times and claimed to be part and parcel of it, but who were merely professional salesmen and promoters who, when there was not a mining boom, were selling sky-line real-estate, worthless oil stocks, or fraudulent securities which happened to be popular with the public. While mining people had this distinction well in mind, the public did not differentiate between the crooked promoter temporarily selling fraudulent mining stock and the honest promoter who made mining finance his life work; and we did little to make this distinction clear to the public or to sweep these money grabbers out of our house. The historic boom of 1927-8 and '29 brought with it the usual crop of crooked mining promoters, and the scandals resulting from their operations forced the Governments into the enactment of laws to attempt to protect the gullible public against the operations of these meanest of thieves and to appease public clamour.

Jan 1, 1934

By Albert J. Kritscher

The Similkameen Copper Project located near Princeton, British Columbia, is operated by the Similkameen Mining Company Limited, a wholly-owned subsidiary of Newmont Mining Company. The orebodies for this project are located on both sides of the Similkameen River for which the project is named. The project involves the processing of an average of 15,000 STPD of andesitic ore, mineralized largely with Chalcopyrite, at an overall plant availability rating of 90 percent. Project life is nominally 15 years. Design for the plant and its ancillary facilities was undertaken by Bechtel Corporation with procurement and construction management by Canadian Bechtel Limited. Construction began in June 1970 and first ore was introduced into process in March 1972. This paper concerns itself only with the project tailing system. The processing plant is located on a bench of glacial stream gravels which overlooks the river canyon. This site represented the only relatively flat area of sufficient size to accomodate processing facilities near to the ore- bodies. Reference is made to Figs. 1 and 2 showing the relationship of project features in plan and profile.

Jan 1, 1973

By Rohan Fernando, David P. Snyder, John F. Burr, Susan M. Moore

"The Mine Improvement and New Emergency Response Act of 2006 (MINER Act Public Law 109-236) was passed by Congress in response to three major underground coal mine accidents in the United States that claimed the lives of 19 miners. The Act resulted in substantial changes in the underground coal industry relative to the use of technology for mine escape, rescue, disaster response and other areas where the lack of these technologies contributed to the fatalities caused by these tragedies. This year marks the 10th anniversary of the MINER Act, which makes it an opportune time to reflect on the events that led to its passage, the changes that have been made since then, and the work that remains to be done.As discussed below, the last decade has demonstrated tremendous cooperative efforts among mining operators, technology innovators, labor, The National Institute for Occupational Safety and Health (NIOSH), the U.S. Mine Safety and Health Administration (MSHA) and state regulators, resulting in substantial improvement of the technologies used for escape and rescue and noteworthy progress toward meeting many of the goals of the MINER Act. While the MINER Act and this article pertain primarily to coal mining, many of the technologies are equally applicable to any underground mining and have already found some acceptance outside of coal.Technology gaps targeted by the MINER ActThe MINER Act addressed several technology challenges:• Problems with donning and switching between self-contained, self-rescuers (SCSRs).• Poor visibility in smoke.• No wayfinding assistance for escape from the mine.• Limited breathable air supply.• Inability to locate trapped miners.• Inability to communicate with trapped miners.• Failure of mine seals."

Dec 1, 2016

In 1960, the Secretary of the Interior, acting under the provisions of Public Law 454, 80th Congress, appointed a Lignite Advisory Committee to aid in programming research on coal (lignite) of the north-central area. The chairman of this committee is the Secretary of the Interior or his delegated representative, and in all meetings held during 1960 and 1961, the Director of the Bureau of Mines, Marling J. Ankeny, has presided. The members of this committee were R. W. Rovelstad, President, Baukol-Noonan, Inc., Noonan, N. Dak. W. E. Keller, Vice President, Northwest Division, Truax-Traer Coal Co., Minneapolis, Minn. A. M. Cooley, Professor of Chemical Engineering, University of North Dakota, Grand Forks; N. Dak.

Jan 1, 1963

By AIME AIME

INSTITUTE HEADQUARTERS, Hotel Statler. On Monday evening, Oct. 28, 1912, the visiting members and guests were informally received by the Local Committee at the Headquarters of the Institute at. the Hotel Statler. The evening was very pleasantly spent in renewing old acquaintances and friendships and in forming new ones. The first session, held Tuesday morning, Oct. 29, 1912, in the impressive Assembly-Room of the hotel, was called to order by David T. Croxton, Chairman of the Local Committee. Mr. Croxton introduced the Hon. Newton D. Baker, Mayor of Cleveland, who extended a cordial welcome to the members and guests present. James F. Kemp, President of the Institute, who subsequently presided at the meeting, responded in behalf of the Institute.

Nov 1, 1912

By Lawrence Adler

MINE hoist ropes have hitherto been selected by successive approximation, a process both tedious and inexact. The proposed expression is a readily solved synthesis of existing data and the following standard equation:' [ W + Wr + (W + Wr) -a 9 (W + W)f + b] n=T [1] For convenience, a glossary of all terms appears on page 564. Since rope weight (W,) and bending load (B) are functions of unit rope weight (Wv), which in turn is a function of rope strength (T), W, and B can be expressed in terms of T. W, as a Function of T: A study of the curve in Fig. 1, unit rope weight vs strength, yields Eq. 2: W. = -f- [2] Therefore Wr = WvL = T. [3] iv B as a Function of T: From Fig. 2, unit rope weight vs diameter, Eq. 4 is obtained: W, = 1.6d2 [4] B is related2 to d and D, and d has been expressed in terms of W, by Eq. 4, so the curve B vs W, (Fig. 3) gives Eq. 5: 177,000 177,000 This may readily be checked from the expression3 for a 6x19 rope, i.e., d3 B = 288,000D Since d2 = 0.625 W, and N = substituting d into the above expression gives Ea. 6: 180,000 180,000 B T, which will be used. [6] Into Eq. 1 substitute Eq. 3 and Eq. 6, noting that f=0.02: W + T 1.02+=T. [7]

Jan 1, 1958

By Joseph Coffman

There are 14 operations that supply 97% of the Market Economy Country (MEC) manganese and contain nearly all of its resources. Six mines account for about 70% of the production and 85% of the resources; there are no known resources that are economically close to those that are currently being mined. Costs (January 1989 dollars) of producing manganese concentrates from the operations evaluated are estimated to range from $ 0.96 to $ 1.86 per long ton unit (ltu or 22.4 lb) of contained manganese. Total MEC demonstrated resources evaluated amount to about 1.2 billion tons of in situ ore containing 474 million tons of manganese. Identified resources amount to about 1.8 billion tons of in situ material. Key results of the study indicate the following: 1. The MEC supply of manganese will be from the currently mined resources well into the next century. 2. Centrally Planned Economy Countries (CPEC's) will be increasingly dependent on MEC manganese ore and concentrate in the future. 3. At the 1976 to 1987 demand increase rate, total MEC resource needed through the year 2000 would be about 282 million tons of in situ material. 4. Transportation and infrastructure support will continue to be major elements of production costs.

Jan 1, 1992

By G. H. Lind

New South Wales has a successful history of pillar extraction stretching back more than 60 years. Various methods of pillar extraction ranging from the rib pillar methods (such as the Wongawilli system) to the more recent pillar stripping techniques (similar to those used in the USA) are discussed in this paper. These discussions are based on the experiences of the author stemming from a recent research tour of seven underground pillar extraction operations in New South Wales as part of the Coaltech 2020 collaborative research initiative. Some operational issues of each site visited are presented before some general comments pertaining to the overall success of pillar extraction in New South Wales are discussed. Generally pillar extraction in New South Wales is on the decline in favour of longwalling. However, the pillar extraction that is conducted is done so along specific guidelines to ensure their success, and these are also discussed.

Jan 1, 2002

By D. S. Tomalin, D. F. Stein

The effect of reducing oxygen to low concentrations on the fracture of high-purity iron single crystals has been examined at 78° and 20°K. It is found that iron single crystals grown by the strain-anneal method usually contain a few occluded grain boundaries which may become embittled in the presence of oxygen, thereby nucleating cleavage fractures. High purity with respect to interstitial elements was found to inhibit twinning and evidence is presented for an orientation dependence of the resolved yield stress. Deformation occurred by slip rather than twinning at both temperatures of testing with elongations of as much as 9 pct at 20°K. THE fracture properties of iron single crystals have been observedl-3 to be a function of temperature, orientation, and purity. Allen, Hopkins, and McLennan1 demonstrated that at 78°K iron single crystals became increasingly brittle as the tensile axis approached the (001) pole of the stereographic unit triangle. Iron crystals with the tension axis near a (001) pole were completely brittle and orientations near the (011)-(111) boundary were very ductile, achieving a 100 pct reduction in area prior to fracture. Later work of Biggs and pratt2 and of Edmondson3 demonstrated that by reducing the carbon content of the single crystals the transition between brittle and ductile failure at 78°K could be shifted to orientations nearer the (001) pole. Ed-mondson went further and pointed out that any mechanism which tended to increase the yield strength of the iron (i.e., carbon addition, pre-strain) also increased the tendency for brittle behavior at 78°K. Thus by a reduction of carbon content Biggs and Pratt were able to obtain ductile behavior to within 20 deg of the (001) pole, and Ed-mondson was able to obtain ductile behavior to within 26 deg of the (001) pole. Edmondson's material had a total interstitial content (carbon, oxygen, and nitrogen) of approximately 60 ppm and, although Biggs and Pratt reported no analysis, indications were that their iron contained comparable impurities. Stein, Low, and seybolt4 purified iron single crystals to a total carbon, oxygen, and nitrogen content of approximately 20 ppm. They observed a lowering of the yield stress with this increased purity, and thus one might have expected an observation of increased ductility. Although they tested specimens of orientations which the previous workers had indicated should be ductile, the crystals failed at a 78°K in a brittle manner with little elongation. Stein noted,' however, that about 90 pet of the failures could be traced in origin to occluded grains. Allen et al.1 and Edmondson3 do not report examination of their cleavage surfaces, but Biggs and pratt2 reported that microscopic examination of the cleavage surfaces of many of their specimens revealed the presence of small occluded grains. Honda and cohen6 and Keh7 have also observed the initiation of fracture at occluded grains in iron single crystals. Therefore, the additional complication of occluded grains must be considered in studying the properties of iron single crystals and the origin of fractures determined if the ductility exhibited by the crystals is to be considered meaningful. Various investigators8-12 have studied the effects of impurities on grain boundaries in high-purity polycrystalline iron. Rees and Hopkins10 showed that the addition of oxygen to low-carbon (0.002 pet) iron weakened the grain boundaries, causing a shift from transcrystalline to intercrystalline fracture and a progressive decrease on the brittle-fracture stress with increasing oxygen content. In addition, it has been shown by Low and Feustel11 that the addition of carbon to polycrystalline iron containing oxygen eliminated grain boundary brittleness. Thus, oxygen can embrittle grain boundaries in high-purity polycrystalline iron, but the addition of an appropriate amount of carbon can eliminate the oxygen-induced brittleness. The oxygen content (19 ppm) of the iron "single crystals" employed by Stein el al. was large enough to suspect impurity effects at the occluded grain boundaries. Allen et al.1 Biggs and pratt,2 and Edmondson3 may have masked any occluded grain problem in their specimens considering the relatively high carbon levels they employed. stein13 demonstrated that the addition of as little as 0.9 ppm C to previously purified (less than 5 x 10-3 ppm C) "single crystals" would increase the elongation from a few percent to more than 20 pet at 78°K and the fracture was not associated with grade boundary initiation.

Jan 1, 1965

By D. Turnbull, H. N. Treaftis

Precipitation of tin from Pb-Sn alloys (lead-rich) occurs by the nucleation and growth of hemispherical cells which consist of tin lomelloe interspersed in the depleted solid solution. Nucleation and growth of these cells and the tin interlamellar spacing at various compositions and temperatures have been investigated. The interlamellar spacing increases approximately as the reciprocal of the logarithm of the supersaturation ratio. For constant initial tin concentration the concentration of cell nuclei increases with decreasing temperature to a limiting temperature-independent value. The kinetic results support the view that the cell growth rote is governed by the diffusion of tin along the cell boundary. In the main, the results confirm the authors' earlier deductions, drawn from resistometric and calorimetric data, about the precipitation mechonism. IT has been shown1, 2 that tin (ß) precipitates from lead-rich (a) PbSn solutions by the nucleation and growth of cells (cellular or discontinuous precipitation). These cells consist of tin lamellae, with a spacing 1, interspersed in a depleted a solution. Reorientation of a also accompanies cell growth. The kinetics of cellular precipitation of tin from lead have been measured by resistometric2, 3 and ca1orimetric1, 3 techniques. The time-transformation isotherms (t equals time; x, volume fraction of specimen transformed) of the initial rapid precipitation, which drains about 60 pet of the tin from solution, have been described by a kinetic law having the form x = 1 —exp (—bt n) [I] where n usually has the value 3.0. It was shown" that this law and the other kinetic facts can be explained satisfactorily if it is assumed that the cells grow at a constant rate and that all the cells nucleate in a time negligible in comparison with the period of cell growth before impingement. Thus, for hemispherical cells b = (2/3)pNG3 [21 where G is the rate of cell growth in cm per sec, and N is the number of cell nuclei per unit volume. The rapid rate of cell growth at low temperatures can be accounted for"' if it is assumed that the dissolved tin drains to the lamellae edges by diffusion along the sweeping cell boundary rather than by diffusion through the a crystal (volume diffusion). For cell growth governed by cell boundary diffusion it was shown, approximately G=2(X° - X° / X° ) DBA / l2 where A equals the thickness of the cell boundary; D R, the coefficient of diffusion of tin atoms within the boundary; and X° and X, are the atom fractions of tin in the supersaturated and saturated solutions, respectively. Zener8 had already shown that, where

Jan 1, 1959

By H. F. Yancey

The investigations described in this bulletin are confined to a study of the washing characteristics of bituminous coals. The major part of the work was conducted by the Bureau of Mines in cooperation with the Engineering Experiment Station of the University of Illinois and the State of Illinois Geological Survey Division between 1918 and 1924, in accordance with the provisions of an agreement between these agencies. The washing characteristics of coals from many of the important coal-producing fields of the Eastern and Central States were examined. The coals of the Pacific Northwest States and Alaska have been studied separately by McMillan and Bird of the Northwest Experiment Station of the Bureau of Mines at Seattle in cooperation with the College of Mines of the University of Washington.2 OBJECT OF INVESTIGATION The object of the investigation of coal preparation by the Bureau of Mines has been to promote the production of better prepared coal and to facilitate the correct selection and design of coal-preparation plants by obtaining as complete information as possible regarding the washability of the various types of American coals and the treatment best suited to each. In addition, some attention has been given to the development of new methods of washing coal. The work naturally divides itself into three rather distinct steps: (1) Development of a systematic method of examining and testing a coal; (2) classification of the American coals on a basis of the occurrence of the impurities associated with the coal in the beds; (3) examination of one or more representative coals of each type.

Jan 1, 1929

By Bruna de Camargo Lemos

O objetivo deste trabalho compreende a realização da síntese de SnO2 dopado com aditivo Sr2 contendo diferentes quantidades molares de SrO (X)SnO2+(1-X)SrO, em que o cátion Sr2+ foi introduzido através do nitrato de estrôncio variando de 5 à 50 % em mol para uma mistura tanto em meio aquoso quanto em meio alcoólico, seguida da calcinação do pó resultante que é feita à 700°C com uma taxa de 10°C/min. Análises de caracterização como difração de raios X, área específica, calorimetria exploratória, picnometria a gás e determinação do ponto isoelétrico das suspensões aquosas foram realizadas de modo a verificar qual o agente dispersante mais apropriado para as características ácido-básicos da suspensão em questão. A partir deste determinar o potencial zeta do composto estudado através da eletroforese. Compostos intermediários a base de estanato de estanho foram identificados, e a deposição por eletroforese foi realizada com sucesso, uma vez que foi possível obter uma suspensão estável a partir dos pós cerâmicos produzidos.

Aug 16, 2017

By W. R. Hardwick

This Information Circular describes the development of block-caving methods and practices by the Miami Copper Co. at the Miami mine in Gila County, Arizona. It is one of a series published by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. This report gives a history of the district and outlines early prospecting and exploration including methods of sampling and estimation of ore tonnage and value at the Miami mine. Early mining methods are described, particularly those that influenced developments in the caving method. Mine exploration, development, and operating methods for block caving are described with particular attention to those factors, physical, economic, engineering, and managerial that have improved efficiency in the mining operations over a long productive period. Extraction, ventilation, wage system, safety, water supply, power plant, and shop facilities are discussed. The last section gives a brief sumary of such costs as are available for publication.

Dec 1, 1964

By DeVerle P. Harris, David E. Euresty

"Potential metal supply refers to metals to be produced from as yet unknown deposits. Naturally, to measure potential supply requires, among other things, inference to the number of deposits, their tonnage, and their grade Thus, probability distributions were constructed for each 400-square mile cell in Northern Sonora, Mexico. A computer system was developed that simulated the occurrence of deposits for each cell, exploration for the deposits, and their exploitation. Evaluation was performed for each deposit by discounted cash flow analysis.An objective of this study was to explore the effect of the transportation network and required road or railroad construction upon potential supply. Consequently, the evaluation system was designed to consider the spatial location of a simulated deposit to the existing transportation network and the market destination. The construction of linkages to connect the deposit to existing transportation arteries as well as the carrying of the concentrates to the intended market were simulated. in terms of cost. The selection of the path took into account the existing terrain. This was done by digitizing topographical maps and representing the topography of the area by an orthogonal grid of elevations. The optimum route was selected by dynamic programming, meeting a prescribed gradient constraint. The potential supply of each cell was determined, allowing for the infrastructure effect."

Jan 1, 2014

By S. Kauvosaari, M. Olofsson, O. Haavisto, M. Kosonen, J. Martikainen

The target in grinding circuit operation is usually to maximise the throughput and energy efficiency while keeping the product particle size on an optimal level for downstream operations. Furthermore, feed ore variations in size and hardness need to be compensated in order to stabilise the process. This is a challenging task for any circuit and requires good instrumentation, combined with careful control design. This study investigates the control of a two-stage iron ore grinding circuit with an AG and pebble mill at LKAB Kiruna KA3 concentrator in northern Sweden. A new control approach based on multivariable model predictive control (MPC) is designed, implemented and evaluated for the circuit. Additionally, advanced instrumentation including a volumetric charge measurement for grinding mills is utilised. The MPC control approach starts with step tests that are used to model the effect of manipulated variables (MVs) like feed rate, water addition and primary mill speed on controlled variables (CVs) such as final product particle size, power consumption and volumetric charge of the mills. In the control implementation phase, the models are then utilissed together with current process measurements and known operating limits to predict optimal future changes for the manipulated variables in order to reach the desired process output values. It is shown that the new control approach improves the stability of the circuit and reduces energy consumption. Keywords: Model predictive control, grinding, optimisation

Jan 1, 2020

By Robert B. Parsons

"First down and four to go. In the game Of football, this is not a bad position to be in. However, in this game of political football, it means that there is still a long way to go. The government in Ottawa has concluded an important agreement with one producing province, and now has at least four more provinces to deal with-B. c., Saskatchewan, Nova Scotia and Newfoundland.On September 1, 1981, the federal and Alberta governments took a significant step forward in formulating an oil and gas policy for Alberta and the rest of Canada on signing a comprehensive five-year agreement that covers taxes, prices, incentives and other fiscal matters related to the production and marketing of oil and gas.This month, Tax Notes examines the main features of the agreement, and offers some eye-opening observations of what the new accord could mean for the future of the Canadian petroleum sector in particular and Canadian business in general."

Jan 1, 1981

By P. Davey Wheeler

San Francisco meeting, September, 1915) IN an article in the General Electric Review, January, 1915, reference was made to the X-ray examination of a steel casting 9/16 in. thick. Fig. 1 shows one of the radiographs thus obtained. All these radiographs showed plainly the tool marks on the surface of the casting. All but one showed peculiar markings the shape of which strongly suggested that they were indeed the pictures of holes in the interior. A circular piece, 1 in. in diameter, was punched from the casting at a point where the radiograph shown in Fig. 1 indicated that a blow-hole should be found. (Location of sample shown by circle in Fig. 1.) Fig. 2 is a photograph of the end of the punching, showing the .hole that was found. Since that article was written it has seemed desirable: (1) to obtain data from which the exposure necessary for any thickness of steel could be at once calculated; (2) to find the thickness of the smallest air inclusion which could be radiographed in a given thickness of steel; (3) to determine in what direction to hope for further progress; and (4) to develop the technique of, radiographing metals. In order to gain some preliminary data, several pieces of ½ -in(12.5mm.) boiler plate were obtained, 5 by 7 in. (12.5 by 17.5 cm.) in size. In one of these, holes were drilled in such a way that the axis of each hole was midway between the faces of the steel and parallel to those faces. The diameters of these holes were as follows: Hole number Diameter 1 1/4 in. = 6.3 mm 2 1/8 in. = 3.1 mm. 3 1/16 in. = 1.6 mm. 4 1/32 in. = 0.8 mm. 5 1/64 in. = 0.4 mm.

Jan 8, 1915

By Robert L. Anderson

A shaft or slope bottom is that portion of a mine that is contiguous to the bottom of the main hoisting shaft or slope. It includes the terminal tracks for loaded-and empty-car storage, locomotive run-arounds, locomotive shops, charging stalls, supply rooms, pump rooms, waiting rooms, and offices for dispatcher, weighmen, and foremen. This paper will deal principally with the arrangement of tracks and the handling of cars on the bottom, but includes other data that may be affected, directly or indirectly, by the bottom lay-out. All of the mines discussed are being operated in comparatively level coal seams.

Jan 1, 1937

By G. Hausen, H. Micka

"Modern signal and power electronics made adjustable-speed AC drives technically feasible and reliable and economically attractive. Cycloconverters are discussed as a proven technology for mine hoists. \IntroductionUntil rather recent technical and commercial advances in power and signal electronics, DC motors were used almost exclusively for applications requiring continuously adjustable operating speeds and torques. More recently, the significantly higher efficiency and the accordingly lower operating costs of AC motors gained importance. An effective and efficient speed control of AC motors requires the control of AC voltage and frequency. Table 1 shows typical applications of adjustable-speed AC drives.CycloconvertersOf particular interest to the mining industry are cycloconverters for hoist drives. The cycloconverter represents by far the simplest, most efficient and most economical means of converting a constant-voltage, constant-frequency supply into an adjustable-voltage, adjustable-frequency supply as required for the speed control of AC drives operating in the frequency range to half of the utility frequency.Cycloconverters feeding synchronous motors or induction motors are ideally suited for slow-speed direct-coupled drives."

Jan 1, 1988

By Josee Boudreau

Transport Canada has regulatory requirements that pertain to the transportation of explosives. An important component includes the requirement for an approved Emergency Response Assistance Plan (ERAP). The ERAP may be traced to the recommendations made by Justice Grange following the enquiry into the Mississauga train derailment of December 1979. Justice Grange recommended that any shipper of dangerous goods must have a plan to control any release of dangerous goods in the event of an accident, and that the plan must be submitted to the Minister and approved by the Minister or by an organisation or person designated by the Minister. The right to ship could be withdrawn at any time if the plan is found inadequate either in its conception or in its operation.

Jan 1, 2010