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By Edward H. Eisenbrey

This paper is primarily concerned with the exploration for massive sulphide orebodies. In a discussion of this type, it seems appropriate to establish a few definitions so that all parties may consider the same beast and its habitat. First, the term "massive sulphides", as used here, not only denotes a body of mineralized rock containing in excess of 50% sulphides by volume, but a mass of sulphides that respond as a conductor to the electromagnetic (EM) systems currently in use in exploration. "Disseminated sulphides" refer to all of those sulphide occurrences that respond to the Induced Polarization (IP) geophysical methods most commonly in use in porphyry copper exploration. This latter definition may also include the disseminated sulphide halos so frequently found associated with massive mineralization as well as banded and stringer sulphide mineralization. It is plain to see that these two end members of our definitions can easily blend into each other. The term "volcanogenic" refers here to any and all geologic processes that have their origin in volcanic activity. Thus we are concerned here with the exploration for massive sulphide ore deposits derived from and affected by contemporaneous and post mineral volcanic activity. Furthermore, most massive sulphide deposits are apparently formed in a submarine environment, deposited with extrusive rocks and sediments and/or chemical hot spring accumulations, then enclosed and protected by the addition of more volcanic and sedimentary material then, probably folded and deformed into one of their myriad of shapes.

Jan 1, 1973

By Makiko Takahashi

A tool is being developed to predict and visualize the microstructural evolution of steels during quenching. This tool utilizes experimental data and reference data that are stored in a database to predict the microstructural development. The visualization tool animates qualitative representation of two- dimensional microstructure drawings as well as the quantitative volume fractions of phases present as a function of time. This is achieved by superimposing the Jominy End-Quench test results over the Continuous Cooling Transformation diagram of the alloy. The predicted microstructure is presented through the web browser to maximize the ease of use. In addition, a parallel coordinate system is used to aid in identifying similarities within the data set by presenting the large number of data at a glance. The results for 4140 steel that was quenched in a wide variety of quenchants will be presented to illustrate the prediction and visualization tools. Keywords: Quenching, Microstructure Prediction, Simulation, Data Visualization, Database, Applet, Animation

Jan 1, 2003

By Bruce E. Kester

The concurrent observation of the phenomena of alkali-aggregate reaction and development of efficient dust collection systems on rotary kilns made mandatory the process modifications to produce low alkali cements. Such low alkali cements as were available prior to these recent changes were either the rare result of low alkali raw materials, the loss of alkalies with dust loss from the kiln stack, or in some instances by the use of CaC12 in the kiln feed to increase volitalization of the alkalies and their subsequent loss or discard with the normal dust emission from the kiln. The relative slowly soluble nature of natural occurring alkali minerals in cement raw materials as compared to the very soluble nature of the alkali salts as present in cement kiln reaction products, either in clinker or in dust emission led to the development of the water leaching system. Two distinctly different problems of leaching are created by the two major systems of portland cement production, the wet and dry processes. The wet process is characterized by moderate dust loads and concentration of soluble forms of alkali in the dust. Further the return of the leached dust slurry does not materially change the characteristics of kiln feed on reintroduction and subsequently does not materially influence kiln operation. The dry process differs in high levels of dust emission and the presence in the collected dust of large amounts of unreacted kiln feed with its sparingly soluble alkali minerals. In the dry process reintroduction of leached dust slurry changes the dry process to what may be classed as a damp process. This change results in some decrease in kiln capacity and creates conditions of operation which are uncommon to either the wet or dry process.

Jan 1, 1963

During the second quarter of 1983, the economic recovery showed further strength abetted by the performances of consumer spending, residential investment, and the slowing down of inventory reductions. Real gross national product (GNP) increased from the first to second quarter at an annual rate of 9.2 percent, compared with 2.6 percent from the fourth quarter of 1982 to the first quarter of 1983 and an overall 1.9- percent decrease in 1982. Total industrial production increased 1.8 percent in July, and productivity as measured by output per man-hour increased 1.3 percent between 1982 and the first quarter of 1983 (table 1). Especially noteworthy .was the performance of real consumer durable goods expenditures, which increased at an annual rate of 32.0 percent from the first to the second quarter (about half of the increase consisted of automobile sales) and real consumer spending, which increased between these periods at an annual rate of 9.7 percent. Residential investment increased at an annual rate of 76.1 percent between the first and the second quarters,1/ and private housing starts by about 38,000 units in both March and May.

Jan 1, 1983

A mining companyÆs approach to managing the risk of theft of explosives and initiating devices should be underpinned by an organisation-wide policy developed with internal and external consultation. It should be based on the principles of sound proactive risk management, planning, monitoring and remedial action. This paper aims to provide mining (and construction)organisations with the rationale and many of the tools they need to control explosive security risks. As with all legislative compliance, they are best managed by incorporating the statutory and legal requirements into company policies, management systems and plans, operating procedures and culture. This is the approach that has been adopted in this paper. Trends we should expect: more prescriptive legislation and stricter government regulations; enhanced enforcement and more prosecution; more sophisticated detection systems, eg airports; additional compliance costs; additional vigilance on record keeping; improved risk awareness and risk communication; wider use of explosives policies, management systems and plans; and additional security staff with investigative skills.It should be noted that mining companies will be required to play their part in reducing the likelihood of explosives, intended for mining purposes, being wrongfully used to threaten, hold to ransom or to injure individuals or members of the public or to produce property damage. This will be done by putting in place safeguards to reduce the risk of theft of explosives while they are under their control. On that basis, this is a business risk assessment rather than a hazard risk assessment. A conclusion of this paper is that mining companies can and should play their part in reducing the supply of explosive materials that can then be used for illegal activities. In fact, mining companies have always had this duty, but now the stakes are higher û æcomplacency no longerÆ.

Jan 1, 2004

A unique sluicing process for recovering tailing impounded in a valley was developed by Electrolytic Zinc Company of Australasia Ltd., West Coast Mines, Rosebery, Tasmania.Earthmoving equipment could not be used as most of the material to be recovered was semi-fluid. A conventional sluking method was also impracticable as there was no suitable working face from which the process could be commenced.Operations started from a flat surface, using special techniques for sinking through the tailing and establishing producing working faces as the sinking process continued.After about 2 years the bottom of the dam was reached and conventional sluicing methods could be used.

Jan 1, 1973

By Edwin W. Tooker

Creation of needed new resources will be accomplished mainly by imaginative and diligent geologic exploration because geologic availability is the key determinant of future mineral supply. Adequate resources of most commodities can be made available for the rest of this century and beyond if they are discovered. Thus conversion of hypothetical and speculative resources into available reserves will provide the principal challenge to earth scientists. Additional problems now compete for our attention. First is a challenge to discover more resources than have been found to date for domestic needs as world-wide demands increase exponentially and as easily found high-grade deposits are rapidly being depleted. New ways to find new types of deposits are required. Second, the United States, a resource importer, increasingly is challenged for access to foreign supplies through stiffening competition and economic or expropriation sanctions. Balancing needs for mineral supply and environmental protection is a third challenge. Geologic explorers must consider statutory as well as economic and technologic requirements, controlled access to public and private lands, competition with urban sprawl or wilderness, limitations on discovery, appraisal and mining methods, and restoration of mined areas. Finally, is the challenge to temper public and private attitudes and assure that decisions bearing on resource problems are based on comprehensive credible facts. While striving to maintain and improve the standard of living, many Americans appear to disdain and mistrust those organizations that provide their material where-withal. Meeting these challenges effectively, and in time, will require careful appraisal of the resource system and the joint efforts of industry, university, and government earth science research.

Jan 1, 1974

By C. Zhou, B. Whisner, J. Carr

Proximity Detection Systems (PDSs) are used in the mining industry for protecting mine workers from striking, pinning, and crushing injuries when they work in close proximity to heavy machines such as continuous mining machines (CMMs). Currently all Mine Safety and Health Administration (MSHA) approved PDSs are magnetic field based systems which can be influenced by the presence of wire mesh that is commonly used for supporting roof and ribs in underground coal m ines. In this paper, researchers at the National Institute for Occupational Safety and Health (NIOSH) characterize the influence of the mesh on the performance of magnetic PDSs by measuring the magnetic field difference around a CMM caused by the presence of the mesh. The results show that the magnetic fields are generally enhanced by the mesh which causes the PDS detection zones to be increased correspondingly. It was discovered that the fields around the joints of two mesh sections have the greatest enhancement and thus deserve more attention. In addition, it is found that the presence of mesh can also cause a variation in the generator current. The influence of mesh is characterized by the change in the generator current with respect to the distance between the generator and the mesh. It was found that the generator current change caused by the mesh can be significant (on the order of ten) when the mesh is extremely close to the generator (e.g, less than 1 cm) and is negligible when mesh is relatively far (greater than 0.15 m). The findings in this paper can be used to develop guidelines and best practices to mitigate the influence of mesh on PDSs. INTRODUCTION The Mine Safety and Health Administration (MSHA) requires operators of underground coal mines to equip place-changing continuous mining machines (CMMs) with proximity detection systems (PDSs) to protect mine workers from striking, pinning and crushing injuries when they work around these heavy machines. Although a variety of technologies can be implemented for proximity detection, the magnetic-field-based PDS that was originally developed at the National Institute for Occupational Safety and Health (NIOSH) has shown great effectiveness in challenging mining environments and currently all MSHA-approved PDSs are magnetic-field-based systems. As shown in Figure 1, a magnetic PDS typically includes two major components----the magnetic field generator and the Miner Wearable Component (MWC). Magnetic fields are generated by injecting a high electric current into a ferrite-rod antenna sealed in the generator. The magnetic field strength detected by an MWC varies with the distance between the MWC and the generator. In a typical PDS, multiple generators are mounted on different locations of the machine. The relative location/zone of an MWC is determined based on the field strengths from different generators picked by the MWC. Ideally, for a PDS to work properly in the underground, the magnetic fields generated by the different generators should be stable and not vary with the environment, as the system would interpret any variation of the magnetic field as a result of the distance change between the machine and the miner wearing the MWC. In reality, however, this is not always the case since magnetic fields can be altered by a number of environmental factors such as the presence of steel wire mesh that has been widely used in underground coal mines for supporting roof and ribs In this paper, the influence of mesh on the PDS performance is investigated and the magnetic field change caused by the mesh is measured.

Jan 1, 2019

It is well known that the crushing and grinding steps in the mineral processing of ores represent a substantial proportion of total energy, cost and carbon emission in mining. For instance a recent study calculated that 36% of the energy consumed by gold and copper producing mines in Australia was attributable to comminution (Ballantyne et al, 2012). Understanding this component of a business is essential in a world seeking to lower production costs, improve earnings and reduce its carbon footprint. The issue commands the attention and support of industry leaders in the mining sector, government, equipment manufacture, engineering design and research organizations. Furthermore, several researchers have often stated that globally, comminution processes consume between 3-4% of the world?s electrical energy production (Daniel and Lewis-Gray, 2011). In 2009-10, Australia?s Federal Government Energy Efficiency Opportunity (EEO) participants in the mining sector used 336.5 PJ, representing approximately 6 percent of Australia's total energy use. It is evident that the current practices of breaking rocks in tumbling mills are relatively inefficient (Fuerstenau and Abouzeid, 2002). Research and improved engineering design has established that a range of improved blasting, crushing and grinding techniques and flow sheets may lower project costs and carbon footprint. These include relatively simple process flow sheet strategies such as gangue rejection or pre-concentration prior to size reduction, a better combination of grinding technologies (both current and new systems), and selection of coarser grind sizes where ore and waste mineralogy allow. Yet, despite this systematic and detailed research, the industry remains somewhat reluctant to implement these strategies. CEEC (Coalition for Eco-Efficient Comminution) was established in 2011 to support knowledge sharing and change in an area of high-energy consumption for the global mineral industry. CEEC is a not-for-profit industry company, funded by grants from world wide industry companies, whose mission is to accelerate knowledge and technology transfer in the field of energy-efficient comminution. The key benefit to the mining sector arising from CEEC?s activities will be an increase in the rate at which more energy-efficient comminution data sets, processes, and technologies are developed, demonstrated, shared and applied. This will contribute directly to the industry?s target of reducing operating costs and carbon emissions. CEEC International Ltd and JKTech Pty Ltd teamed together to facilitate the inaugural CEEC Workshop, in June 2012. The purpose of the workshop was to produce a roadmap to provide guidelines for how (1) operations can achieve best EEC practice in the short to medium term, in collaboration with vendors, engineering companies and other service providers, and (2) what R&D is needed to achieve paradigm change in EEC in the medium to long term, e.g. 75% reduction in comminution energy in 10 years.

Sep 1, 2012

By T. Oberthür

The Great Dyke of Zimbabwe constitutes the world?s second largest reserve of platinum group elements (PGE) after the Bushveld Complex in neighbouring South Africa. Within the Great Dyke, economic concentrations of PGE are restricted to sulphide disseminations of the Main Sulphide Zone (MSZ), which are currently mined at the Ngezi, Unki, and Mimosa mines. Near-surface oxidized MSZ ores have a large potential. Their total resources are in the range of ca. 160 ? 250 Mt; however, all previous attempts to extract the PGE from this ore type proved uneconomic due to low PGE recoveries (<< 50 per cent) achieved by conventional metallurgical methods. Within the ores of pristine, sulphide-bearing MSZ, the PGE are bimodally distributed. Platinum occurs mainly in the form of discrete platinum group mineral (PGM) grains (mainly bismuthotellurides, sulphides, and arsenides), whereas approximately 80 per cent of the Pd (and some Rh) is hosted in pentlandite. Within the oxidized MSZ ores, the PGE are polymodally distributed. Whereas arsenide- and sulphide-PGMs, making up ca. 25 per cent of the original Pt content of the ore, largely remain stable (relict PGMs), the remaining PGMs are disintegrated. The base metal sulphides are destroyed, partly releasing their base metal and PGE contents, and are replaced by iron oxides or hydroxides. Unspecified amounts of the PGE are redistributed and either form secondary PGMs, are found in chemically and mineralogically ill-defined (Pt/Pd)-oxides or hydroxides, or in iron-hydroxides, Mn?Co-hydroxides, and in secondary silicates. The problematic processing of oxidized MSZ ores is attributable to their complex nature and polymodal distribution of the PGE, prohibiting a significant upgrading of the ores by conventional metallurgical methods. Therefore, only bulk leaching methods are viable for ore treatment, and novel metallurgical methods have to be developed for the processing of these ores. Our ongoing work aims at locating the PGE in their mineralogical form in order to understand the mineralogical balance of the PGE in the ores and thereby facilitate the evaluation of metallurgical options for their recovery. A short overview on options and recent advances regarding the recovery of the PGE from oxidized ores is given.

Jan 1, 2012

By M. P. Davies

"Risk, the product of probability and consequence, is an integral part of mining. Whether evaluating exploration priorities, determining property acquisition potential, reviewing the components of an operating mine or assessing environmental/closure issues, the concept of minimizing risk is central to economic and technically appropriate decision making.Until recently, risk evaluations have tended toward a strongly mathematical basis. With this previous trend, it was essential to establish precise probability density functions to all assessed components or issues where often little information was available. The combined effect of the seemingly complex analyses with corresponding insufficient data often resulted in either a poorly executed risk evaluation or no evaluation whatsoever; either result not acceptable for optimal decision making. This paper presents a simple and practical procedure to carry out risk assessments for the mining industry. Although simplistic in nature, the power and usefulness of the technique is immense. The basis for the procedure involves combining deterministic assessments (often “gut feel”) with appropriate probabilistic descriptors. The resulting procedure, termed Potential Problem Analyses, or PPA, can be used anywhere an evaluation of risk will assist in optimizing technical and/or economic decisions. As will be shown, a key element of the PPA procedure is the multi-disciplinary input the framework allows which makes the method ideal for a teamwork approach to decision making."

Jan 1, 1997

Andy H. Vassiliou – Introduction Ladies and gentlemen,.good evening and welcome to the Paul F. Kerr Memorial Symposium dinner. I believe we are all here to honor the memory of a great teacher and advisor, and a true friend -- Professor Kerr, or Dr. Kerr, or to most of us who were his students, "Pappy" Kerr. Most of us who attended the Paul F. Kerr Memorial Symposium earlier today at the New York Hilton had the opportunity to read, or listen to, or discuss scientific papers presented in honor of Dr. Kerr. In addition, all of the speakers had the opportunity to reminisce about their association with Dr. Kerr, who was credited as having contributed substantially to their graduate education and the development of their careers. Dr. Kerr&apos;s two daughters -- Ruth and Nancy -- who attended the Symposium at the Hilton are also here with us tonight. I think we should keep tonight&apos;s festivities on an informal basis since we are all old friends or former students of Dr. Kerr. Some of us may want to say a few words about our experiences at the time we were students at Columbia, and hopefully include some anecdotes relating to Professor Kerr. I would like to invite everyone to do so, but first we have arranged for two of us to be the lead speakers, whom I will introduce in a few moments.

Jan 1, 1985

By W. A. Thatcher

Nearly three years of experience in Spanish Honduras has placed the writer in possession of many facts concerning its resources which may be of interest to the Institute. According to the most trustworthy surveys, Honduras is bounded on the north and east by the Caribbean Sea; southeasterly by the river Segovia (or Wanks), which flows into the Caribbean at a point called Cabo Gracias a Dios (Cape Thanks be to God), long famous as the favorite hiding-place of the celebrated pirate, Morgan ; southwardly by a corner of San Salvador, the Bay of Fonseca, and the Republic of Nicaragua; Guatemala and San Salvador form tile western boundary. It is one of the five republics composing Central America, has a population of about 310,000 and an area of 150,000 square miles, lying between the 13th and 16th degrees of N. latitude, extending from north to south 200 miles, between the Atlantic and Pacific, and 400 miles from east to west, between Guatemala and Cape Gracias a Dios. It is composed of 13 States or Departments, under one common law. The principal resources are valuable woods, hides, rubber, tobacco, coffee, fruit, cattle, silver and gold. It is of the mineral resources of the country that I will speak, calling attention to the most noted mines, and their relative position to Tegucigalpa, the capital. The introduction of foreign capital into the country dates back about eleven years, and to-day there are at least twenty-five well organized companies.

Jan 1, 1892

By Andrew B. Cecala, Emily J. Haas, Jay F. Colinet

Researchers from the U.S. National Institute for Occupational Health and Safety (NIOSH) studied the impact of an unregulated dust control technology (the Helmet-CAM) and a regulated dust control technology (the continuous personal dust monitor) within a sociotechnical system (STS) framework to mitigate respirable dust sources. The results address how to best incorporate the overarching principles of meta-design STS during the technology integration process. Specifically, quantitative and qualitative data show that a prominent focus on the social factors within an STS framework could help reduce organizational unpredictability and may improve communication within the system to help reduce technology adoption time.

By W. A. Padgham, J. A. Brophy

About 85 % of the 350 tonnes of gold produced by 25 mines in the onhwe t Territories (NWT) since 1935 has come from the Yellowknife-area mines, Con and Giant , which exploit shear zones in Archean mafic volcanic of the Slave Structural Province. Four percent of the total production has been from Archean iron formation-hosted depo its, mainly from Lupin Mine, which today produces more gold than Con and Giant combined and has been primarily responsible for the increase of WT gold output from 5 to 12 tonne per year since 1981. The remaining gold ha been won from the following deposit typesall but the last being in Archean rock : sedimentary-volcanic contact depo its uch a Discovery and Salmita (10 %); turbidite-hosted quartz-vein depo its uch a Camlaren and Ptarmigan (1%); Proterozoic deposits such as Shear Lake and Fox (1#) . All but I% of WT gold has come from the Archean Slave Structural Pro ince, which is also the premiere exploration area for gold deposit types that have yet to be productive in the NWT. These types include stratabound gold in mafic and in felsic volcanic rocks (eg. , at Indin Lake and Courageous Lake, respectively) as well as gold in plutonic rocks (eg. Anialik Gnei Complex). Deposits similar to those in the Slave have al o been found in the Archean Ennadai Belt of the Churchill Structural Province. In the Cordillera. there is potential for placer gold and for gold associated with Cretaceou intrusions.

Jan 1, 1986

By J. A. Pontius

The Cresson Deposit is located in central Colorado within the historic Cripple Creek Mining District. The deposit has moved from its initial discovery in 1990 to full production in less than five years (current reserve nearly two million ounces). This accomplishment required a great deal of cooperative teamwork between the exploration, development, permitting and corporate groups. Nowhere was this cooperation more evident than in the construction of the geologic block model. The detailed modeling of gold and its metallurgical characteristics formed the foundation upon which critical financial and design decisions were based.

Jan 1, 1995

By John E. Conley

The need for lightweight aggregate for use in concrete products ,and structures has caused the Bureau of Mines to undertake an investigation to determine the availability of suitable raw materials and to study methods, procedures, and equipment to supply that need. Evidence is at hand to prove that the shortage of lightweight aggregate is nationwide. A survey recently covered in a report (13)5/ by the Construction Branch of the National Housing Agency has pointed out the locations in which lightweight aggregates are produced. A study of this information discloses that the producing centers are widespread, and that certain areas, notably the region east of the Mississippi River, and especially the sections along the Atlantic coast line and the Southeastern States, have only a few such plants. Certainly, many localities are badly in need of installations equipped to provide an ample supply of high-grade lightweight aggregate. The work undertaken by the Bureau of Mines includes investigation of the use of clays, shales, slate wastes, coal-mine wastes, diatomite-clay combinations, and various other &apos;mineral mixtures as possible raw materials. Likewise, special consideration has been given to the development&apos; of equipment and techniques to produce the lightweight products.

Jan 1, 1949

By K Fiedler, A Newell, P D. Munro

Test work is the foundation upon which the success of projects and subsequent operations is laid, reflected in Professor Arthur Taggart’s pithy observation: ‘Make your mistakes on the small scale and your profits on the larger scale’. Indeed, Professor AllanTrench has succinctly noted that ‘Get the metallurgical characteristics wrong and you don’t have a project’.With deposits becoming lower grade, more structurally and mineralogically complex, final products requiring lower levels of impurities and tailings management demanding more attention, test work now assumes even greater significance in the acceptance and successful execution of a project. This paper is the first in a series aiming to stimulate thought on the metallurgical test work process by getting back to the fundamental basics through exploring and providing some guidelines for the metallurgical testing world, noting preferred practices as well as precautions and mitigations. This covers the key characteristics of metallurgical test work programs, including what needs to be done, sample selection, quality control and associated drivers, and most importantly, selecting, assessing and managing test work facilities. CITATION:Newell, A, Munro, P D and Fiedler, K, 2018. Metallurgical test work – between a rock and a hard place, in Proceedings 14th AusIMM Mill Operators&#39; Conference 2018, pp 15–32 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By AIME AIME

OVER-ALL operations of the oil industry, as measured by production of crude oil and consumption of products, are almost exactly of the same magnitude as a year ago. Does this mean that the great oil industry has been undisturbed by the war? Has this industry, so vital to the prosecution of the war and to the maintenance of our way of life, been unaffected in its operations? No indeed - changes within the industry are great. It has been called upon to revamp its trans¬portation methods so as to move about one fourth of the total amount of crude and refined products by railroad tank car instead of by ocean-going tankers. Its fundamental internal economy, based on maximum gasoline yield from a barrel of crude, has been relegated to memories of the past. Rationing of oil products, which has been forced upon us in face of an abundant supply, is not only disagreeable medicine but is in itself completely disruptive to the marketing end of the-business.-

Jan 1, 1942

By Courtney E. Cleveland

THE gold deposits of the Pioneer and Bralorne mines, in the Bridge River district of British Columbia, are closely associated with a long, narrow intrusive body of extremely variable composition, outcropping on the northeast side of Cadwallader creek and lying almost entirely within the property boundaries of the two companies. Other masses of the same type of intrusive rock are found in the district, more or less along the line of the main axis of the Pioneer-Bralorne in trusive, and have associated with them variable amounts of gold-quartz mineralization (Figure 1). The ore deposits of the district have been the subject of investigation by officers of the Geological Survey of Canada at various times during the past 25 years, and articles on the geology and mines of the district have been published by various individuals in technical journals. A list of the more important re-ports follows: SELECTED BIBLIOGRAPHY

Jan 1, 1938