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By Edmund S. Leaver, Charles E. Van Barneveld

In response to numerous requests from metallurgists and operators for information regarding the status of the sulphur dioxide leaching process , developed at the Southwest experiment station of the U. S. Bureau of Mines , Tucson , Ariz . , the following statement has been prepared . A more complete report is now in course of publication and will appear as Technical Paper 312. This process was devised to provide a cheap and efficient method for treating the so- called "porphyry " copper ores of the Southwest which generally contain both " sulphide " and "nonsulphide " copper minerals , mixed in such proportions that they can only be satisfactorily treated by a method which will concurrently recover both the sulphide copper and the nonsulphide copper . The latter term has been adopted to include all the minerals commonly referred to in operating phraseology in the mills of the Southwest as " oxidized" , " oxide " , or " soluble " copper . confident that the sulphide dioxide leaching process , as developed by us with the cooperation of the Miami Copper Co. and the Arizona Copper Co. , is suitable and commercially available for a wide range of ores .

May 1, 1922

By Mi, Dong Liang, Jingyuan Bai, Victor Zhou, Xujun

Squirrel cage induction motors are the mostly used motors at present. Currently, the rotors of the squirrel cage induction motors are produced by aluminum die casting technique with the advantages of low cost of rotors. It is well known that the copper’s electrical conductivity is around 40% higher than that of aluminum. If copper is used to replace the current widely used aluminum in rotors, the total loss of motors will be reduced, hence increasing the overall motor efficiency. Copper rotors can be used to produce high efficiency and even super premium efficiency motors without enlarge the motor frame size. Considering the huge quantity of motors, the die casting process is the best solution to produce copper rotor with economic cost. Because of the characteristics of copper, it is difficult to produce copper rotors by casting similar to that done in aluminum rotors. In order to improve the die casting quality of copper rotor, a new tooling structure was developed and the casting process of copper rotor was simulated and analyzed by Any-casting software. The filling process, solidification process, inner gas distribution and residual melt modulus were analyzed. It was found that the design of symmetrical runner and inner runner on both sides was helpful to reduce the impact of molten copper to the cavity surface during the filling process. The use of Slag traps array can reduce die casting defects inside the end rings. That will be helpful to improve the rotor quality. INTRODUCTION Squirrel-cage AC induction motors are most widely used in the world. In 2017, the total installed capacity of AC motors in China has reached more than 1.2 billion kW, and the annual power consumption accounts for about 60% of the total national electricity consumption. To improve the efficiency of squirrel-cage motor will be helpful to energy conservation and environment protection. There are several ways to improve efficiency of induction motors, using copper rotor is one of the most effective solutions. It is well known that the copper’s electrical conductivity is around 40% higher than that of aluminum. If copper is used to replace the current widely used aluminum in rotors, the total loss of motors will be reduced, hence increasing the overall motor efficiency. Copper rotors can be used to produce high efficiency and even super premium efficiency motors without enlarge the motor frame size.

Jan 1, 2019

By G. J. Hartman

The Fort Cady in situ borate mining project involves recovery of boron from a mineral deposit located over 1400 feet below the surface. The resource recovery method is being developed using in situ mining technology employing weak acid solution injected directly into the ore body. As the acid contacts the calcium based ore (primarily natural colemanite), the contained borate values are digested as boric acid. This boric acid solution is then pumped to the surface by use of submersible pumps. At the surface the borate values are recovered as a finely divided solid white powder after a series of chemical reactions and precipitations resulting in the production of calcium borate. The refined product is then sold under the trade name CADYCAL 100.TM All environmental permits for up to a production rate of 90,000 tons per year have now been obtained. These permits required an Environmental Impact Study (EIS) for federal lands and an Environmental Impact Report (EIR) for the private portion of the property. Regulatory permitting took over 5 years to obtain all authorizations for this operation. The ore body has an average thickness of 118 feet extending over 273 acres. At a production rate of 90,000 tons per year with only a 70 percent resource recovery allowance, in place reserves are sufficient to sustain production for over one hundred years.

Jan 1, 1997

By Richard A. Thomas, Liming Yuan, Lihong Zhou, James H. Rowland

Hydrogen (H2) gas released during battery charging can result in cross-interference for carbon monoxide (CO) sensors used for early fire detection and compromise the integrity of the mine atmospheric monitoring system (AMS). In this study, a series of laboratory-scale and full-scale experiments were conducted to evaluate the responses of different CO sensors to H2 gas. In the laboratory-scale experiments, constant H2 concentrations in the airflow, from 100 to 500 ppm, pass through sensors. While in the full-scale experiments, increasing H2 concentrations generated as a byproduct from charging the batteries at the battery charging station rise to the sensors under different ventilation scenarios. The H2 concentrations at the CO sensor location were measured using H2 sensors and were correlated with the CO sensor response. The effects of ventilation and sensor location on the CO sensors responses were also analyzed. The results of this study can help mining companies to select appropriate CO sensors and improve the deployment of these sensors to ensure the safeguard of underground miners.

By J. B. Dilworth

I. INTRODUCTION. THE purpose of this paper is, first, to give a general account of a little-known coal-district of SE. Kentucky, its topography, drainage, and mineral resources, for those who may be interested in its economic development; and secondly, so to describe the geologic features of the field as to furnish available data to those engaged on the broader problems of Appalachian coal-geology. The data from which the major portion of the paper has been prepared were obtained, in professional investigations for private individuals and corporations, within the last decade. The area under review, defined by a heavy line on the map, Fig. 1, lies between Little Black and Pine mountains, and extends from Harlan on the west to a N-S. line crossing Looney creek 3 miles from its mouth on the east. This area can be divided for description into a Western and an Eastern Division. The character of investigation pursued in the Western Division, below Fugitt creek, was very different from that employed in the Eastern. In the former, only a rapid reconnoissance was attempted : such coal-openings as had been made by prospectors or by citizens in obtaining fuel were visited, their sections measured and, in many instances, sampled. Elevations were obtained barometrically and approximate locations sketched on a small-scale map. In a field where the coals are so well opened, the reconnoissance method gives a very fair idea of the number and character of the principal beds and their relative positions, and affords much evidence for their correlation over wide areas, without permitting the more refined work required to discover all the seams of the measures and to determine the details of geologic structure.

Feb 1, 1912

By Terry Muldoon

In conventional noncoal, room-and-pillar mining, the cutting machine is frequently a major source of airborne dust. Water is often used for dust control. An evaluation of typically used water systems during this program showed that they reduced dust levels by 60 to 70 percent over dry cutting when at least 0.5 gpm of water was applied. These systems, however, are only marginally effective in maintaining compliance levels and the added moisture causes operational problems. During the program, three additional dust control systems were designed, fabricated, and evaluated. The first, a hollow cutter bar, was designed to capture dust in the kerf at the cutting zone. The system was only marginally effective in reducing dust levels due to its lack of control of other sources. Large quantities of material captured by the system made it operationally questionable. The second, a machine mounted exhaust system, was extremely effective in capturing virtually all the dust generated in the heading. The captured dust was ducted out of the heading and exhausted downstream in the crosscut. Exhausting the dust without scrubbing, however, creates problems for personnel working downstream of the cutting machine. Successful application would require changes to the mine ventilation system and mining sequence. The third, foam, injected foam from an onboard generator through a channel to the cutting zone at the tip of the bar. Test results showed that foam, using 1/3 to 1/2 the total fluid quantity, was equally effective when compared to the mine's current water system.

Jan 1, 1983

By D. L. Griffith

THE realization by metallurgists of the important effect that traces of impurity may have upon the properties of a metal, and their steady demand for purer and still purer metals, have made the special cools for 'trace' analysis of increasing value. In the United States at least, spectrographic analysis is becoming the standard method for determining the impurities in zinc die-casting alloys. The Hudson Bay Mining and Smelting Company, as a producer of virtually pure zinc, uses the spectrograph to control the purity of its products, and-as the electrolytic method is employed here-to control both the impurities in the electrolyte and those 'trace' elements, which, while they do not contaminate the zinc, have a great effect on the plating efficiency. The general plan of the laboratory is shown in Figure l; the housing for air purification, which is on the roof, is indicated by broken lines. One of the chief factors affecting the layout was the easy way in which a spectrographic assay can be spoiled by contamination. To minimize the quantity of dust tracked in, the laboratory was made separate from the general research laboratories, and an office was placed between the two. This arrangement has its drawback because of the traffic through the office, but it has effectively cut down dust. For similar reasons, the available space was subdivided into a number of small rooms, and the air currents in the laboratory were so arranged that dust would be carried where it would do least harm. Air is drawn in at the roof over a 50-kilowatt bank of Calrod heaters, through Annis air filters, by a No. 4 Sirocco fan. Most of it is forced into the spectrograph room, but some goes to the office and darkroom. The air flow is from the spectrograph room, through the plate-measuring room, into the chemical laboratory, where it is exhausted by a No. 1% Sirocco fan on the fume hood. Air can also re-circulate from the plate-measuring room back to the heater. The arrangement is such that the air in the laboratory is maintained at higher pressure than the outside air; consequently, no dirt enters through cracks about the windows and doors. A thermo-regulator holds the temperature constant within one or two degrees; only on the hottest days in summer does the temperature rise enough to affect the focus of the instrument.

Jan 1, 1940

By H. B. Charmbury

In Pennsylvania there are two distinct coal regions, bituminous and anthracite, in which the mining conditions and production trends are different. Bituminous mining is more mechanized, and production is increasing. This report is concerned specifically with the bituminous area. The bituminous coal industry apparently is facing a shortage of miners and mine officials which may become acute by 1970. Since 1949, when Pennsylvania had more than 100,000 bituminous coal miners, the number has steadily decreased. There are two principal reasons for the decrease of certified miners and mine officials. These reasons are the fact that apprentices are almost a thing of the past and the fact that the image of the coal miner is a poor one to people in general and to parents in particular. This has contributed greatly to the high average age of our miners today. The average age of all those employed in the mines is 50. Yet it is known that the progress in mine mechanization requires younger and more alert men to operate the newer type equipment.

Jan 1, 1966

By C. R. Ross

"THE ASSESSMENT of pneumoconiosis-producing dusts in mines and other industries is usually undertaken for one or more of three reasons: (1) To compare dust exposures at particular operations with standards of permissible dustiness in order that hazards may be evaluated and preventive procedures initiated where required.(2) To study particular operations with the objective of improving dust control devices or procedures by locating dust sources. (3) To obtain data which, along with the results of medical investigations, may assist in understanding the causes of dust-induced diseases or aid in the establishment of permissible standards of dustiness. Most dust measurements are made for the first of these reasons -to evaluate dust hazards so that they may be controlled. For this purpose, four quite different assessment techniques have been in widespread use for many years. One of these is based on the konimeter, an instrument familiar to most .Canadian mining men; a second on the impinger, which is also widely used in Canada, and almost exclusively so in the United States; a third on the thermal precipitator, used extensively in Britain and South Africa; and a fourth on the tyndallometer, a light-scattering instrument used in Germany."

Jan 1, 1960

By D Bertoldi, C Haines

"The Waihi Gold Mine (WGM) operated by OceanaGold New Zealand Limited is a wholly owned subsidiary of the OceanaGold Corporation of Australia. Traditionally WGM has stockpiled and processed separate campaigns of open pit and underground ore. The ore is processed via a conventional semi-autonomous grinding (SAG) / ball circuit (SABC). The low aspect SAG mill operates in a closed circuit with two 20" cyclones, whilst the ball mill is also a closed circuit with a 10" cyclone cluster. A major wall movement in April 2015 ceased open pit operations indefinitely, 18 months ahead of the mining plan. This immediately reduced the forecast mill tonnage leaving two options: begin campaign milling or change the operating strategy and target lower throughput. Additional cost pressures necessitated improved milling cost efficiency. The immediate ore restriction limited processing alternatives to within the existing major infrastructure. Available comminution circuit survey data laid the foundation for developing a comminution model using the JKSimMet™ software package (version 6, created by KJTech). A number of flow sheet variants were then evaluated based on predicted throughput and efficiency. The comminution models suggested opportunities for improved efficiency lay in reducing throughput and increasing utilisation rather than on/off campaign milling under the existing operating philosophy. A series of process alterations followed, delivering new cost efficiencies that maintained the current $/t processing cost. This paper aims to review the change in circuit performance and examine the decisions and challenges faced following the transition from a high tonnage SABC circuit to lower tonnage SABC circuit.Citation:Haines, C and Bertoldi, D, 2016. The Transition from Semi-autogenous to Autogenous Milling at Waihi Gold, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 303–312 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By Malti Goel

"Ferrous and non-ferrous metals industries are source of both direct and indirect greenhouse gas (GHG) emissions. Metal industry accounted for 29.7% of the total GHG emitted from the Indian industry sector in 2007. Aluminum is second largest contributor after steel. Indian Aluminum industry has been growing and is adopting several effective measures for better efficiencies through process change and waste utilization. Improvement in the energy efficiency can form the basis of monitoring reduction in emissions. Under the National Action Plan on Climate Change 2008, National Mission for Enhanced Energy Efficiency (NMEEE) aims to upscale the efforts to unlock the market for energy efficiency improvement on a public private partnership (PPP) basis. For a transition to low carbon economy industry is undertaking voluntary measures through scientific and technological innovations both in upstream and downstream sectors. In this paper an attempt is made to overview recent developments in Indian Aluminum industry as well as summarize scientific & technological challenges and prospects.IntroductionAluminum plays a vital role in industrial development. It is a substitute for different type of materials ranging from wood to copper and steel. The aluminum industry has high energy consumption and high contribution to greenhouse gases from carbon dioxide and perfluorocarbons (PFCs) emissions. It is estimated that CO2 equivalent burden of aluminum industry is about 1% of total anthropogenic emissions. The anticipated world growth rate is 3.5% for aluminum demand. Through measures to reduce both direct and indirect CO2 emissions, electricity consumption was reduced from 25 kWh / kg of Aluminum in 1998 to 15 kWh / kg of Aluminum produced in 2008. It is targeted to further reduce it to 10.8 kWh. Aluminum industry is also responsible to about 60% of all PFC emissions. The PFC emissions are harmful to environment, accumulate in surrounding vegetation and contaminate. Efforts to reduce PFC emissions from aluminum industry started early and reduced to 0.5-1 kg / tonne in 1990 [1] from 12-15 kg / tonne in 1940. Since 1990s to 2000 it further reduced to 0.2 -0.4 kg / tonne as seen in Fig. 1. The Global Aluminum Sustainable Development Initiative (GADSI), targets perfluorocarbon (PFC) specific emissions reduction of 80% for 2010 relative to 1990."

Jan 1, 2011

By R. B. Khumalo, T. Chauke, T. Mtshali, F. K. Mulenga, B. Makgate, N. M. Chiloane, T. Moyane, V. C. Madanda

While high production rates are important for the profitability of a mine, the influence of geotechnical engineering cannot be ignored. In block caving, a high-stress level is required for cave propagation; this is one of the core elements for ore recovery. Therefore, stress distribution and geological structures play a major role in the planning and layout design of the mine. This paper explores the influence of stress and geological features on the design of the mine from the feasibility study phase. The geology and stress measurement of the mine were determined through logging and overcoring, respectively. This study found that while production rate is the primary operational consideration, the long-term layout design of the undercut face advance, face angle, drawpoint spacing, and undercutting sequence is mainly governed by the stress orientation and major geological structures. Moreover, widely spaced drawpoints result in isolated draw zones, consequently, resulting in ore loss and early dilution whereas closely spaced drawpoints affect the stability of the major apex pillar. This paper also provides insight into how operations can leverage stress distribution to optimise mine layout and safety in massive mining methods.

Nov 24, 2025

By K. V. Godfrey

With the increasing need to exercise better control over mill circuits has come a requirement to develop rapid, accurate means of measuring circuit parameters. One of the most important parameters is the assay of the material in the circuit (or about to be introduced to the circuit). To date, most on-stream analysis has been performed using X-ray fluorescence equipment. Neutron activation offers an alternative method in certain circumstances, and one which has several interesting advantages. Recognizing the need for a simple, safe neutron activation unit suitable for on-stream analysis in the mineral industries, Atomic Energy of Canada Limited has designed, built and tested the SHERLOCK system. One prototype (SHERLOCK I) is located in Ottawa and is now used primarily in research. A second prototype (SHERLOCK III) is located in Vancouver at the laboratories of B.C. Research. This unit is being used for some development research and for evaluating the unit in specific applications. Most of the work completed to date has been aimed at proving the technique and in developing some of the parameters needed to design systems for a milling plant. Funding for the work has been through research grants and through sponsor¬ship by interested companies.

Jan 1, 1971

By J. R. Rau

While refuge chambers are common place in most underground mining projects, there are different philosophies as to what life support systems are to be considered and how these systems are to be applied. Case studies in the underground mining industry have examples of emergencies where the external compressed air and power supply to the refuge chamber were compromised due to proximity of services to the fire location. In 2005, The Department of Industry and Resources, Western Australia, drafted guidelines that listed specific requirements for refuge chambers which included a secondary life support system that would operate independently of external sources. The objective of this document is to examine what critical life support systems are essential for safe entrapment in the event of an emergency and to examine considerations for their application.

Aug 1, 2013

By R. O. Pynnonen

This publication is an analysis of reports to the Bureau of Mines of 44 fatal accidents that occurred during the operation of rubber-tired, front-end loaders in the mineral industry. The causes of the accidents, the nature of the work being performed, and recommendations for preventing similar accidents are included.

Jan 1, 1967

By J. F. Barkley

Two major problems in the operation of air preheaters for boilers are corrosion and the accumulation of deposits on the heating surfaces. Corrosion or loss of metal necessitates replacement of parts; the accumulation of deposits decreases the size of the gas and air passages, resulting in increased pressure drop for the same gas flow, and also affects the heat transfer. These items, either singly or together, limit the capacity and efficiency at which the equipment can be operated and affect its availability, even causing undesirable shutdowns under extreme conditions The field and laboratory work on regenerative air preheaters described in this report covers research on the relative corrosion resistance of different materials, such as various metals, special metal coverings, and fired clays, and studies on deposits, their nature, analyses, and corrosive effects. This is the first report on cooperative work of The Air Preheater Corp., of New York City, and the Federal Bureau of Mines.

Jan 1, 1953

By Charles E. Locke

IN gathering material for this review the aid of the individual members of the Milling Committee was invoked and the assistance received is hereby most grate- fully acknowledged. The replies were much alike; almost everyone stated that in 1932 his operations had been cur- tailed or stopped entirely, that the only activity and progress were in milling gold ores, and that the Hadsel mill' looked like a coming machine in the crushing and grinding field. However, further inquiry and search have shown that the year was not quite so barren of developments as the foregoing statement would indicate.

Jan 1, 1933

By Michael J. Beus, Jan G. Patricio

INTRODUCTION The U.S. Bureau of Mines, Spokane Mining Research Center, has been conducting and documenting rock mechanics research in the Coeur d’Alene mining district for the past ten years (1, 2, 3, 4, 14, 15). A current project combines the information gathered from rock mechanics instrumentation, geologic structure, and analytic techniques to improve shaft and support design for the deep mines of the district (3). This project required knowledge of the anticipated loads and the physical properties of the rock mass to provide accurate input data for computer design models. Several techniques have been utilized to determine the physical parameters including the USGS (U.S. Geological Survey) solid inclusion probe, the CSIR (Council for Scientific and Industrial Research) biaxial and triaxial strain cells, and the CSM (Colorado School of Mines) dilatometer. This paper describes the determination of the in situ modulus of deformation in three mines over a period of three years and the evaluation of these results as they applied to this project. The need for in-situ rock mass properties such as the modulus of deformation has stimulated research and development of a large number of instrumentation techniques. One area of continuing interest involves various methods of radial borehole dilation. This concept was pursued by Menard (9) with an apparatus known as the pressure meter, which is used frequently in soil mechanics. Other developments in rock mechanics include the CPC (cylindrical pressure cell) by Panek (11) and the dilatometer by Rocha et.al. (13) in Portugal. The CSM dilatometer, which also utilizes this technique, was chosen for this project because it required a small amount of background study, was inexpensive, and could easily be combined with other experiments being planned for the test locations. Although no previous field applications to hard rock (compressive strengths greater than 20,000 psi) has been documented, the instrument was selected since good results have been achieved in granite, oil shale, and several coal measure rocks (11, 12).

Jan 1, 1977

By Michael J. Beus

The National Institute of Occupational Safety and Health-Spokane Research Laboratory (NIOSH-SRL) have developed a Shaft Conveyance Monitoring System (SCMS). Assessment of current hoisting technology has shown that monitoring wire rope tension and conveyance position and load directly from the skip or cage top offers several significant safety, production, and maintenance advantages. The SCMS consists of conveyance position and guide displacement sensors, a battery power supply and charging system, and a new sensor to measure hoist rope tension. This device provides a warning of the occurrence of ?slack rope? a particularly dangerous condition. A 2.4 GHz radio link transmits data to the hoistroom. A reduced scale hoisting test facility has been constructed to test these components prior to field trials. The advantages of monitoring wire rope tension and conveyance position and load directly from a skip or cage top will be discussed. Field tests are underway in full-size shafts to refine the concept and evaluate long-term reliability and maintenance requirements. Application of this technology may result in decreased maintenance costs as well as safer, more productive hoisting operations.

May 1, 2001

When I was first asked to give a paper on work-life balance in the mining industry I was both excited and aware of the incongruity of my position. I have never worked in mining operations nor have I had any experience that approximates the on-site lifestyle. IÆm not really an adventurer or a traveller, I prefer writing and research to hands-on activities and IÆve never worked further than twenty minutes away from home. The perspective I offer is thus largely an objective one. I say largely since I grew up in a family where my parents work arrangements involved long-distance commuting; my dad continues to work FIFO at a coalmine in Blackwater until this day. Perhaps my tortoise-like existence is a rebellion against his flighty movements. The analysis I will be presenting today draws together a variety of sources, from member anecdotes and research on FIFO and work-life balance to the popular philosophy writings of a bald Englishman with a French name. I am speaking of the famous writer, Alain de Botton, whose television show æThe Consolations of PhilosophyÆ you may have seen on the ABC. Work-life balance is a term that gets a lot of mileage in corporate brochures and at breakfast seminars. But like many terms that get bandied around in the human resources circuit, from æteam synergyÆ to æperformance optimisationÆ, I am frequently perplexed as to what it actually means. Corporate websites are at pains to emphasise the high priority that they place on the needs of the whole person. Yet in terms of substantive content, a commitment to work-life balance often seems to translate into little more than the option to take a few morning yoga classes in exchange for working a seventy-hour week. As extended work hours have taken their toll, leading to high attrition of professionals across all industries, employers are increasingly expending resources to discover just what lies behind this buzz word. The challenge for companies is to find meaningful strategies to help employees better integrate different aspects of their lives in a new era of work, as employees are sending the message that they are not willing to play work, social life and leisure off against each other in a zero sum game.

Jan 1, 2005