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By G. Wren

As base metal sulphide resources become increasingly challenging to process, producers seek alternative options to treat concentrates. This study considers the mineral, elemental, and leaching character of a West Australian nickel sulphide deposit (Cosmos Nickel Project). After a brief review of the published work bench top leach tests were conducted to examine the factors which impact the kinetics of nickel sulphide leaching such as particle size, temperature, acid strength and type, concentration of copper sulphate and sodium chloride, and oxygen partial pressure. The effect of sodium chloride was considered due to the common occurrence of hyper saline water at West Australian nickel sulphide mine sites. Ultrafine grinding to an 80% passing size of 10 µm resulted in high nickel leaching efficiency. Moreover, higher concentrations of acid, copper(II) and sodium chloride also gave higher nickel and cobalt leaching efficiencies but arsenic precipitated as FeAsO4. Under the most suitable conditions the extractions of nickel, cobalt and arsenic at 90oC after 6 hours were >95%, 90% and <5%, respectively. The comparison with results from high pressure operations indicates the possibility of using a hydrometallurgical flowsheet based on fine grinding and atmospheric pressure leaching and warrants further investigations.

Jan 1, 2014

By David Burgess

The paper describes experiments at the Somerset Mine, Colorado, under a cooperative agreement between U.S. Steel and the U.S. Bureau of Mines. A test was made of the tube bundle method of mine air sampling which was developed for European longwall mines; some 300,000 running feet of tubing provided continuous monitoring at 39 locations. Carbon monoxide concentrations were obtained with standard deviations of less than 1 ppm and oxygen concentrations with standard deviations of less than 0.20 percent. A base level of CO index (ppm CO evolved/pct 02 removed)) was determined to be 0-20 through most of the passageways of the mine. However, in one working section where the coal was initially hot (about 180°F within a pillar) the CO index was demonstrably higher, >20 trending upward to about 60 when smoke appeared and the section was sealed. The data are discussed in terms of laboratory experiments on CO evolution from coals.

Jan 1, 1975

By Víctor Barrientos

El presente trabajo es un estudio realizado donde se determina la pérdida de ingresos de una empresa minera, producto de la detención de camiones y cargadores frontales en una faena minera a cielo abierto. El cálculo de esta pérdida de ingresos se realiza a través de un modelo que estima el volumen del movimiento de roca de la mina y los ingresos que este genera en función de la disponibilidad y rendimiento de los camiones y cargadores, y su interacción conjunta.

Sep 1, 2015

By B. K. Slone

The depth at which it becomes more economical to use slope access as opposed to box-cut access for near-surface coal reserves, termed "transition depth," can be established for a given coal property by considering cost estimates for those parameters that determine respective access method. Fourteen parameters that influence access cost were identified and ranges determined. A Transition Depth Formula was developed to permit determination of the better method of accessing a reserve, given such information as highwall slope, road width, total bench width, pit dimensions, road grade, belt component costs, pumping costs, and cost of overburden removal and reclamation. In most cases, in Appalachia, studies indicate that the transition depth ranges between 20 and 30 m.

Jan 1, 1998

Protect rescue workers fighting fires or mine personnel temporarily working in hot environments from heat stress. Approach A specially designed ice-cooled vest is worn while working in hot environments where cooling the mine air is not possible. How It Works The vest holds a total of 44 individual ice cells in packets that are firmly held near the wearer&apos;s skin. These ice cells remove heat from the wearer, reducing heat stress and increasing comfort. The locations of the ice cells and packets are shown in the diagram. The vest is constructed in three layers with the outer layer being aluminzed fiberglass cloth. Its aluminized surface reflects radiated heat, and its fiberglass cloth provides fire resistance and strength.

Jan 1, 1979

By Martin Fischer

A new method for the quantitative image analysis of complex microstructures in steel is presented. Microstructures in modern steel grades on the one hand become more and more complex while on the other hand the size of the constituents is scaled down ever further. For these reasons it is increasingly difficult or even impossible to access reliable quantitative information on ratios, shapes and spatial distributions of individual phases and constituents by utilising traditional metallographic analysis methods. The presented new analysis approach is object-based. Its basic processing units are so-called ?image objects? which reflect the pictured structures by merged groups of likely related pixels. By the use of image objects, information on shape, graphical texture and spatial distribution of the microstructural constituents can be processed. With these additional data available, it is possible to quantitatively analyse complex microstructures. This is demonstrated by the application of the method to SEM images of different multiphase steel grades. Because the analysis routine is fully automated, the analysis of large amounts of image data is possible and thereby the investigation of statistically relevant areas of microstructures.

Jan 1, 2009

By George A. Laird

THIs old and once famous district played, through its enormous production of silver and gold, an important part in the history of the State of San Luis Potosi. According to a pamphlet prepared under the direction of the Governor of the State, Sr. Don Blas Escontria, and presented to the visiting members of the Institute during the Mexican meeting of 1901, this district is situated 20 km. east of the city of San Luis Potosi, in a range of mountains of moderate height, extending 135 km. N. and S., and 16 km. E. and W.; and the mineralized area hitherto developed is about 600,000 sq. m. The history of the district, as given by the record dated 1778, and formerly kept in the Sail Francisco convent, says that it was discovered in 1575 by Sr. Don Pedro Irarte, and adds that the city of San Luis Rey de Francisco de1 Potosi received its name (in allusion to the famous Potosi mines in Bolivia) by reason of the remarkable productiveness of its gold- and silver-mines in the first period of their exploration, during which they paid to the Crown, as quintos (the fifth part of the product), $97,000,000, as appears from the accounts of the royal treasury. The amount of the quintos paid during the " bonanza period " of 80 years was $72,000,000. The larger sum first mentioned probably represents a longer series of years. But either will suffice to indicate the great wealth of the mines. In 1663, the decadence of the industry began with the caving-in of several mines, concerning which the record of 1778, already cited, says, in substance, that on Good Friday one of the owners in the enterprise, in view of the unfavorable prospect of a lawsuit in which he was engaged, set fire to the timbers supporting the underground galleries and workings of the Sail

Jan 1, 1905

By Gerald Verbeek, David Tara

"When selecting an impact hammer to drive a particular pile, the decision is often based on local experience. In those cases, the contractor falls back on previous experience or draws on the experience of the hammer manufacturer to select the hammer that will be able to do the job. Obviously, a more scientific approach would be to perform a pile driving simulation using one of several commercially available software packages (e.g., GRLWEAP, AllWavePDP or PDPWave).However, this type of analysis requires quite a bit more effort. First, an accurate model of the pile driving process has to be developed, which includes a model of the soil profile at the job site and input into the analysis program. Then, the model must be analyzed to assess whether the combination of hammer, pile and soil model work.Over the years, numerous individuals and organizations have tried to develop something that would fit nicely in between these approaches: something more advanced than a gut feeling yet something that could be done on the back of an envelope; in other words, a “Goldilocks” approach — not too simple, not too complex, but just right.Screening Tool CriteriaThe goals of the approach are twofold: (1) select the appropriate impact hammer to drive an open toe steel pipe or H-pile, and (2) then use the model for the subsequent high strain dynamic testing (HSDT). The Goldilocks approach centers around five different criteria.1. Maximum Driving StressTo minimize the risk of damage, the maximum driving stresses are generally limited to 80 to 90% of the yield stress (fy) of the steel section. This approach does not consider issues such as hammer alignment, initial imperfections, denting and/or elastic buckling, and pile material fatigue history. However, even when these issues are not applicable, limiting average stresses to 0.9fy or even 0.8fy does not necessarily mitigate the risk of pile damage (Mostafa, 2011)."

Jan 1, 2017

By George H. Popper

The Bureau of Mines has evaluated the extent of phosphate resources available for recovery by the experimental borehole mining method in the Southeastern Coastal Plain of the United States- Phosphate re- sources at overburden depths greater than 30 m are as a rule currently unsuitable for recovery through conventional mining methods because of economic, environmental, or technical considerations. In the identified deposit areas, borehole mining operations are projected to yield a more favorable rate of return and to be environmentally more desirable than conventional surface mining. Borehole mining resource estimates presented in this study are preliminary and designed to serve as a basis for future resource evaluations, as the current data base is relatively sparse and incomplete. The resulting resources have, therefore, been classified as hypothetical and speculative and are subject to up- dating as additional exploratory data become available. Hypothetical and speculative resources amenable to borehole mining are estimated to total about 385 billion metric tons (rat) of phosphate matrix with a minimum in situ grade of 5 pct P205. With projected borehole mining capabilities and current conventional beneficiation procedures, this resource would make available approximately 64 billion mt of phosphate rock product at an estimated grade of 30 pct P205.

Jan 1, 1985

By K. Lang

The use of high-efficiency electrical submersible pumps (ESPs) for large scale, open pit mine dewatering operations provides a good example of how technology, products and services from the oil and gas industry can be adapted to the mining industry. In this case, the mine is Goldcorp?s Peñasquito in the Zacatecas state of Mexico, at the Peñasco and Chile Colorado open pit deposits. The technology, products and services are from Schlumberger artificial lift (AL) and Schlumberger industrial water services (IWS). Overview of high-efficiency ESPs This section provides a brief description of the basic components, specifications and operating capacity ranges for the ESPs compared with traditional or conventional dewatering well pumps. This information helps to establish how ESPs provide certain functional and economic advantages over conventional pumps in a mine dewatering application. A schematic of a high-efficiency ESP in an oil and gas (O&G) application is shown in Fig. 1.

Sep 1, 2013

By Frank L. Marley

Mexican silver mining operations have existed prior to the sixteenth century. Recovery processes throughout the centuries were developed at the many mining localities and have progressed through smelting, the patio amalgamation process to cyanidation and flotation. A study of the present silver mining zones is reported in which the ores are evaluated in terms of the mineralogical constituents, their state in the matrix and the effects these are noted to impose upon the efficiency of recovery. Silver mineral identifications were by quantitative ore microscopic and scanning electron microscopic energy dispersive X-ray analysis.

Jan 1, 1982

By P Hagan, S Wang, D Li, B Loh

A study was undertaken to quantify the differences in performance between a full-length encapsulated cable bolt and a partially encapsulated cable bolt. Much research has been reported on the differences in cable bolt design and operational parameters such as borehole diameter and grout type with much of this based on the Laboratory Short Encapsulation Pull Test (LSEPT). However, there is a gap in knowledge surrounding the effect of anchorage length on load transfer and cable bolt performance particularly with respect to the role of the bulb in modified cable bolt designs. The objective of this study was to expand the existing knowledge base of cable bolt performance with the intent of developing a revised design criterion. Alongside a comprehensive review of current cable support theory, design and practice, a series of pull tests was undertaken to compare each anchorage method using a high capacity modified cable bolt. The results serve to confirm earlier work on fully encapsulated anchorage. Both the peak load capacity and stiffness of the fully encapsulated cable bolt were nearly double that of the partially anchored cable bolt. When the tests were repeated in an oversized borehole, while there tended to be more variation in performance, there was little significant difference in the mean results. In addition to anchorage length, there are other factors that contribute to cable bolt performance including in order of sensitivity: embedment length, water-to-cement ratio of the grout, type of grout and borehole diameter. CITATION:Loh, B, Hagan, P, Li, D and Wang, S, 2018. A comparison of the performance of fully versus partially encapsulated cable bolts based on laboratory-scale testing, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 291–302 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By Dave Minney

The South African mines health and safety regulations require that mine management establish a quality management system for rock support material. Quality control of resin capsules used as a support medium in South Africa is specified under SA National Standards No 1534. Experience has shown that this specification, while addressing the chemical and physical aspects of the products, but does not address the required performance criteria. In order to address this shortcoming, the industry has put a lot of emphasis on short encapsulation pull tests, performed insitu, in the underground workings of the mine. This is also fraught with many shortcomings, particularly as regards site availability, cost and repeatability of results. To try and address these issues, the Department of Mechanical and Aeronautical Engineering at Pretoria University were approached to develop equipment and machinery that could produce reliable, repeatable results in a laboratory environment which reasonably simulates installation practice underground. The test method is based on the ASTM F432-95 Strength Index test, but modified to use push test rather than pull tests. The paper describes development of the test method and the preliminary results and findings of the work.

Jan 1, 2007

By Jerry J. Gray

Transportation charges for mineral commodity movements in western Oregon and western Washington were determined mainly by a stratified random sample canvass of producers. Total 1965 mineral production value for this area was $53.3 million; the cost or charge to move this production from the mine to the consumer or to the point of consumption was determined to be an additional $38.7 million. Thirty seven companies were contacted as a sample out of a total population of 349; the statistically expanded sample production value deviated 3.6 percent from that obtained by the Bureau&apos;s annual canvass. The agreement between the sample results and the canvass totals demonstrated the effectiveness of the sampling method for obtaining data with a predesigned level of accuracy. For comparison, the north-central Idaho and western Montana area was studied, A random sample experiment was designed, but because of the dominance of a few major companies, a random sample technique would have required more visits to producers than if only the larger firms were contacted. Eighty-four percent of the 1966 mineral value ($198.6 million) was accounted for by interviewing 27 firms out of a total population of 199. Total transportation costs or charges for the area were $26.7 million. The significant difference observed between the relationship of minerals production value and transport charges between the two areas investigated can be attributed to the difference in the minerals produced. The western Oregon and western Washington region is a nonmetals-producing area as opposed to the predominance of metals production in the Idaho-Montana region.

Jan 1, 1968

By Scott Turner

Since my whole life has been spent in the mining business , I naturally tend to address my remarks particularly to the newly- graduated mining and metallurgical engineers among you . To a certain extent , all forms of engineering principles are involved in the training of the mining engineer , and most sorts of engineering are certainly utilized by him , so that every one of this graduating class is concerned with the field I propose to discuss . The fact that , beginning with to - day , you will always be styled engineers , indicates that you have passed successfully through preparatory school , and have survived the hard grind of the technical college . One object of your training here has been to instruct you in accurate , close , and clear thinking . Your minds have been taught to act directly , calmly . and always to the point . By now , you should know how to get facts , look far , and think through . You are supposed to be willing to recognize and adopt sound engineering principles and practices , in so far as they are known to you , and to furnish character , ability , and devotion to your calling . Some of you may have had a general college course before coming here to specialize in engineering . Where that has been possible , I hope it is the case , since a liberal educational course tends to make the alumnus more flexible and adaptable than the purely scientific graduate. The broader education enables one to change , with less serious loss , from one job to another; ready adaptability is a great asset ; the engineer should be capable of much more than a single special task . The necessary preliminary training for a professional occupation is intellectual in character , involving knowledge , and to some extent learning , as distinguished from mere skill . The well -balanced engineer is expected to embody a happy combination of theory and fact , of pure science and material reality ; experience shows that he is apt to give a good account of himself , once he gets the chance . For the long pull , the importance of unquestioned integrity can not be overemphasized . Leaders of big business sometimes have need for a man as agile and unscrupulous as a cat on a back fence ; on occasion , they may have to employ brilliant , smart , spectacular , and crafty people , but when the special purposes for which such men are hired have been accomplished , they are no longer wanted . Given natural health , intelligence , ability , and adequate training , probably the characteristics most admired in the young employee are steadiness , dependability , and loyalty . The last is the best . If you can not be simple , direct , and faithful in your dealings with your administrative superiors , no one will want you for long . I believe these points are of primary importance to the young engineer . Your groundwork must be right before you can get far . These personal characteristics are what eventually determine your relations with men and affairs . They are vital in the human engineering which may be a large part of your work .

Aug 1, 1932

By H. A. D. Kirsten

Written contribution by L.J. Besaanst I am a Mechanical Engineering Technician (T3), and wish to further my education to at least NHD (T4) level. I read your paper in the Journal of The South African Institute of Mining and Metallurgy with great interest, and must compliment you on its brilliance. However, there are some questions I should like to ask, and certain points I should like to highlight. I should appreciate your comments. Written contribution by J.F. Curtis The comprehensive and finely detailed survey of, and proposals for, engineering education in South Africa reflects the author&apos;s wide experience in the needs for, and the provision of, such education. This paper wil make a major contribution to the enhancement of the profession of engineering and the improvement in quality of engineering activities in South Africa. Contribution by G.W. Annandalet I have studied your paper in some detail, and am of the opinion that it makes an important contribution to the topic of the development of technological manpower, which is currently being debated in South Africa at al levels. Debate on this topic has risen above the level of academic discussion; it has been discussed by the Economic Advisory Council of the President, and is being considered at Ministerial level. Author&apos;s reply to L.J. Besaans Thank you for your contribution and complimentary remarks. As you have pointed out, there are certainly many aspects that will have to be addressed in the resolution of the crisis in engineering education. I trust that the following comments satisfactorily answer the queries you have raised. Author&apos;s General Comments Since publication of the paper, attention has become focused on the provision of employment opportunities an aspect not dealt with specifically in the paper. The following comments serve to indicate some of the directions in which job opportunities will have to be developed in the numbers that will be required.

Jan 1, 1991

By B. R. Conard

Occupational epidemiology of the nickel-producing industry has found that inhalation exposures to certain nickel-containing substances are linked to respiratory cancers and to nonmalignant respiratory endpoints. Establishing such a linkage, however, is complicated by the fact that some diseases occur long after exposure to a causal agent (i.e., some diseases have long latencies). Furthermore, most chemical agents (especially nickel substances) vary significantly in their toxicological properties and their concentrations in workplace air have varied over processing history. Because of these complications, it is critical to understand historical exposures to specific nickel substances. To assist in this effort, the author focuses on the history of smelting and its related processes at Vale Canada’s (Inco’s) Ontario operations in the first half of the 20th century.

Jan 1, 2012

By Randolph C. Specht

A two year study was made of the waste disposal of the pebble rock phosphate industry. Solid slimes are impounded in large settling areas and the process water is re-used. Clear effluent was not found to be toxic to fish, or animal life in field tests or in controlled experiments.

Jan 1, 1950

Using a Mark IV surface force apparatus, adsorption of dodecylamine hydrochloride on mica has been studied at pH 5.7 in the presence and absence of octanol. With amine alone, the repulsive forces between mica surfaces are reduced due to charge neutralization and attractive hydrophobic force; however, the latter is of relatively short-range with its decay length less than 2 nm. In the presence of amine and octanol, the hydrophobic force becomes more significant, its decay length being extended up to 6.5 nm. The increased hydrophobicity in the presence of octanol is attributed to the co-adsorption of the neutral surfactant with dodecylamine, which increases the packing density of hydrocarbons on the mica surface. The increased hydrophobicity due to co-adsorption is reflected in the improved floatability of silica when using octanol as an extender.

Jan 1, 1993

By Clyde L. Brown

Recent developments in portable communication equipment for use in emergency recovery work following mine fires and explosions have wade possible a convenient and dependable means of directing rescue teams working under hazardous conditions. INTRODUCTION Mine rescue and recovery operations following; fires and explosions are frequently conducted under adverse conditions that require the use of oxygen breathing apparatus by members of a 5- or 6-man team. Conventional apparatus used for this purpose for many years was equipped with an oxygen supply adequate for at least 2 hours. The design of the apparatus is such that the nose passages are closed with a clamp, and breathing is accomplished through a mouthpiece connected to the apparatus by tubes and arranged to prevent inhaling air or gases from outside sources. The use of the mouthpiece has presented difficulties in the development of telephone communication because of the wearer&apos;s inability to speak while wearing the mouthpiece. The method of conducting operations of rescue teams requires a person to direct operations at a fresh-air base as close to the rescue team as possible. At least one standby rescue team and 2 or 3 other persons assigned to various tasks are stationed at the fresh-air base. An efficient and reliable means of communication between the director of operations and the rescue team is necessary for reasonably safe and efficient work in hazardous areas.

Jan 1, 1957