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By W. G. Stevenson

With the author's background of extensive experience, this paper delineates the role of the prospector in modern-day exploration programs. The stages in the development of a prospect to a producing mineral district are outlined, and examples are given from the Ross River area of the Yukon Territory and the Peachland and Highland Valley areas of British Columbia.

Jan 1, 1970

By J. M. Wempen

Booster fans in underground coal mines are often located using the concept of a neutral point. Normally, intake airways are maintained at higher absolute pressure than return airways; therefore, air leaks from intake to return. By adding a significant pressure force to a region of a ventilation system, booster fans installed in a return airway can increase the pressure in the return so that air leaks from return to intake. This is commonly referred to as recirculation. The neutral point occurs at the location in the system where the pressure difference between [ ] the intake and the return airway is zero. At this point, there is no leakage or recirculation. Ideally, placing a booster fan near the neutral point minimizes leakage and recirculation. However, in practice, the position of the neutral point is not static and it changes as the ventilation system parameters change. Booster fans have the potential to increase the capacity and efficiency of coal mine ventilation systems. However, these fans add a significant pressure source to ventilation systems and can create areas where the pressure in the intake is less than the pressure in the return causing recirculation. In systems with multiple booster fans, there may be multiple recirculation paths and, as the capacity of these fans increases, recirculation is more likely to occur.

Jan 1, 2012

By Vijay Kumar, Serhat Baycan, Karsten Beckhans

For the deep foundation of podium and tower of the Kuala Lumpur City Centre, BAUER (MALAYSIA) SDN. BHD. constructed 225 bored piles with diameter range of 2.0 to 2.5 m. In order to comply with the depth requirement of the design, for planning purposes and preparation for site, the drilling equipment was required to achieve a maximum drilling depth of 150 m. Actual piles constructed on site were deeper than 120 m. These dimensions caused superlative challenges which included but were not limited to; controlling the open hole stability over time with polymer, installing 70-ton heavy steel cages, pouring up to 550 m³ concrete continuously, in conjunction with installation of kingposts into workable, fresh concrete. The piling works were executed with a BG 72, the biggest drilling rig globally available, and the stringent verticality of the pile bore holes which required approval prior to cage installation. For verification of verticality, Bauer’s patented Drilling Inclination System was successfully used.

Nov 1, 2022

By Davenport, Edmund S.

THE specific aim of this work has been to study certain forms of internal deterioration which occur in tungsten filaments when subjected to high temperatures under various conditions, and to determine the cause of such deterioration. This would naturally lead to a consideration of methods of control or means of prevention of the phenomena. The deterioration was first noticed as a peculiar condition in the grain boundaries of certain tungsten filaments which had been burned t for long periods in lamps. In these cases it was noted that the grain bound aries contained a number of minute black dots which were at first thought to be non-metallic inclusions. It was demonstrated later that these dots or pits, as they were designated, could be readily produced by burning filaments in an atmosphere of flowing hydrogen. This method was convenient and adequate for the purpose, and was adopted for most of the work discussed in this paper. The evidence accumulated to date indicates that these pits arc actually small voids between the grains. The purpose of this paper is to, present the information on this interesting subject gathered during a period of about 3 years. As applied to tungsten, the subject appears to be of considerable importance, experience having shown that this pitting is frequently associated with poor performance of filaments in lamps.

Jan 1, 1927

By Lauri Pesonen

"Although electrical energy use at copper smelters is typically about 15-20% of operational costs, it is something which is not very often analyzed and discussed at a detail level in technical papers and presentations. This paper aims to list different equipment configurations per smelter area and estimate their electrical energy consumptions versus unit of material processed. In addition chosen smelting technology and oxygen enrichment rates affect the overall electricity consumption and therefore some overall guidance is provided for efficiency gains.INTRODUCTION In principle, processing plants, such as copper smelters, require electrical and chemical energy together with some degree of human input to process input materials into desirable output form like metallic copper. From the standpoint of metallurgical plant designers, the thermodynamics of smelting, when it comes to releasing and conserving thermal energy, is sufficiently understood and frequently discussed in the literature in detail, but judging from the quantity of publications, the way how we exactly utilize electrical energy is not. This article is meant to illustrate how electrical energy consumption is distributed among different process units and equipment types at copper smelters using various smelting technologies. In general, typically about 15-20% of operational costs are related to electricity and at locations with high electricity prices the potential savings can be quite significant for the overall profitability of the plant operations. In today’s tight profit margin environment any potential savings are more than welcome. The purpose here is not to promote any certain copper smelting technology, but to open a discussion on how and where we use electrical energy, and how the overall energy use could be lowered with the implementation of newest electric power saving designs and solutions. Using the principles outlined in this article, it should be fairly easy and straightforward to replicate the calculations and even improve them wherever it is seen necessary for the greater benefit for us all in this industry"

Jan 1, 2017

By M. H. Rana

"A survey of our knowledge in the field of rock mechanics is presented from the viewpoint of applications in the mining industry. Aspects of rock mechanics of special interest to the industry are enlarged upon, with emphasis on the avoidance of over-generalization. The relationship between fundamental and practical rock mechanics is discussed, and the need for cooperation between the university and industry to further our knowledge of -useful rock mechanics is emphasized. An attempt has been made to establish the scope of rock mechanics, as applied to problems in the mining industry. This is brought about by projecting rock mechanics as a tool to be intelligently used rather than magic, capable of producing ""miracles."" Continued education is important for individuals engaged in the application 0f rock mechanics in the mining industry. The scope of this education is discussed from a viewpoint of better communication between industry and the education and/or re-search establishments engaged in this work.Finally, the dangers of over-emphasis on rock mechanics are mentioned, but a justification of the in-vestment in rock mechanics programs in mines is also presented."

Jan 1, 1966

In the flotation of fine particles, problems arise which do not occur with coarse-ground pulps. For example, the presence of colloidal or near-colloid- al gangue particles gives rise to ex- cessive entrainment in the froth, with reduced grade as a consequence. If the values themselves are finely dissemi- nated, the recovery usually decreases as the particles diminish in size, so a low recovery is combined with poor grade. Sutherland and Wark (1955) referred to the complications arising from the presence of fines, indicating (p.382) that fine grinding "introduces diffi- culties that have not yet been satis- factorily overcome". At the time of writing, very little work has been done on fines flotation specifically, yet the groundwork has been well laid. The availability of better scientific instruments, together with the general advance of understanding in a wide variety of relevant research fields, has taken us a long way toward finding the reasons behind the problems as- sociated with fines, and also toward finding practical solutions. It would be useful to define what is meant by "fine" particles before going further. To some extent, the definition is somewhat elastic as far as flotation is concerned, because the density of the particles has a bearing on whether or not they act as fines. But in general we are dealing with particles less than about 20 pm in Diameter.

Jan 1, 1984

By Robert E. Baker

Cortez Gold Mines, the United States' third largest primary producer of gold, commenced continuous operations on January 10, 1969. The decision to proceed to production was made in March of 1968 and construction of the mill and stripping operations for the pit began in April and July, respectively. Anomalous conditions on the slope of Mt. Tenabo along the Roberts Mountain thrust fault zone were discovered by the U.S.G.S. while conducting geochemical surveys in the old Cortez silver district. Following the discovery of gold an intensive program of drilling was organized. Drilling outlined an orebody with 3.5 million tons of ore averaging 0.28 ounces of gold per ton. It was on the basis of this reserve that a 1700 t. p.d. cyanide plant was designed. Needless to say, with such a limited ore reserve, economies in design and construction would have to be observed. Cortez Gold Mines is a joint venture with American Exploration & Mining Co., The Bunker Hill Company, Vernon F. Taylor, Jr., and Webb Resources, Inc. , as partners. American Exploration & Mining Co. is the operating partner.

Jan 1, 1969

By R. B. STEWART

A few days ago, while reading a report of the late Dr. Robert Bell in preparation for this afternoon's meeting, I found some impressive figures concerning the magnitude of the Hudson Bay basin. From the waters of the Bay itself, this great territory extends eastward 500 miles, westward l,300 miles to the Rocky mountains, and southward to the source of the Red river. It has a width of 2,100 miles from east to west, and a length of l,500 miles from north to south. Its area is almost three million square miles. It is not, of course, my intention to review the natural resources of this vast territory, but to confine my remarks to that portion of it adjacent to the waters of Hudson bay. A number of erroneous ideas exist in the minds of many concerning this northern country, especially as regards its latitude and climate. Burwell, at the entrance of Hudson strait, is in the latitude of 60 degrees or roughly that of the north of Scotland. The southern end of James bay has about the same latitude as the northern end of Vancouver .island.

Jan 1, 1928

By Edward L. McHugh

The study area, which comprises 28,443 acres within the Jacumba Wilderness Study Area, is in the California Desert Conservation Area, and along the U.S.-Mexico border 25 miles west of Fl Centro, CA. The U.S. Bureau of Mines evaluation of mineral resources is based on examination of mining claims, known mineral occurrences, and mineralized zones during the fall of 1983. Limestone resources were identified inside the study area; tungsten resources may he present. Metasedimentary rocks intruded by Cretaceous Quartz diorite predominate in the study area. Tungsten and some gold have been found in skarn zones along intrusive contacts; limestone deposits are in the pre-Cretaceous rocks. Tertiary and Quaternary volcanic flows, pyroclastic rocks, clay beds, and diatomite in lake deposits nave been investigated for possible non-metallic resources. Evidence of mining or prospecting was found at 26 sites in or just outside the study area. In 1983, 106 claims were held in 13 claim groups. One claimant was sporadically prospecting for gold on claims in the north part of the study area in 1983, and gravel was being mined from alluvium 1/4 mile to the east.

Jan 1, 1985

By D. G. Puglio

This Bureau of Mines study covers 25 underground mines that were active in the Upper and Lower Freeport and Lower Kittanning coalbeds in 1976. The coal ranges from low to medium volatile in rank; its primary use is for steam generation. Seven mines emit more than 100,000 cfd of methane gas; those mines are the deepest and largest producers. The methane gas content of three core samples of the Lower Kittanning coalbed was estimated by the direct method. A sample from a depth of 320 feet contained 0.5 cu cm of gas per gram, at 620 feet there was 0.8 cu cm of gas per gram, and at 1,060 feet there was 11 cu cm of gas per gram. These results suggest that methane control problems will be encountered in the future as deeper coal is mined.

Jan 1, 1979

By C. E. Baltzer, W. H. Harper

"This study has been developed to illustrate the trend and pattern of distribution applying to the quantities and costs of the fossil fuels used, and the related amounts of electricity generated, in the thermal segment of the Canadian electric utility industry.Traditionally, Canada's requirements for electric energy have been preponderantly met by hydraulic power. The need for augmented supplies of thermally generated power has mainly developed since the close of World War Il-in an era that has seen drastic decline in the production of indigenous coal and buoyant expansion in the supply of oil and natural gas. Although coal currently is faced with serious competition from the fluid fuels, the utility industry in particular promises an advancing market for coal, because of its abundant resource, at prices less likely to show sharp increase. For Canada as a whole, this trend has been progressive since 1959, and, unbelievable as it may now seem, the extent of the advance by 1975, particularly in Ontario and the Prairie Provinces, may well be as much, or even more, than the present rate of consumption for all purposes.The text and the tables and charts are arranged to focus attention on: the growth of thermal genera ting capability; the historical trend in consumption of fuel and the related production of electricity; patterns of distribution by types of fuel and thermal capacity; the relationship of steam to other sources of thermal capacity; and the quantities, costs and related percentages of electricity generated by types and kinds of fuel used, both regionally and provincially."

Jan 1, 1966

Objective A cable bolt can be a strain-measuring device as well as a supporting device in underground mines. Placing instruments on a cable bolt allows certain characteristics of a rock mass, such as high strain and load, to he evaluated during mining and provides a means for mining engineers and mine inspectors to forecast a potential roof fall. Background Thousands of cable bolts are installed in U.S. mines each year. Studies performed by NIOSH researchers show that support loads can exceed the yield point of the steel, which can result in unstable ground conditions that pose direct safety hazards for underground workers. Rock falls can also create secondary hazards, such as caved escape ways and blocked ventilation passages. Development of methods and tools to assist in the evaluation and selection of rock supports could reduce the number of unplanned rock falls significantly. Approach Instrumented cable bolts developed at NIOSH’s Spokane Research Laboratory were used along with existing ground control systems to monitor rock mass loads and movement Axial and shear loads on the cables are determined as these loads are transferred to strain gages embedded in the king wire. In longwall, room-and-pillar, or underhand cut-and-fill mines, rock mass loads and movements can be detected down to microstrains of stress or millimeters of movement. By detecting such small amounts of ground movement and support load, early intervention to prevent a roof fall is possible, and miner safety and health are increased. How it Works Up to 10 strain gages are embedded in the king wire at whatever locations a mine ground control engineer may specify. The gages m either be set in pairs in the same plane to detect shear or set at 90° angles to detect loading in three dimensions. The cables are up to 5 meters long if they arc to be grouted with resin or up to 15 meters: if they will be grouted with cement. They arc capable of holding m ultimate lend of 214 kN and produce reliable readings to 178 kN, as shown in the calibration curve. The cables are fitted with an instrument plug for monitoring the gages and a special head for insertion into the rock. A data acquisition system, such as a Vishay strain indicator box, Campbell Scientific, or Omnidata system, is required to obtain the data for load and displacement calculations.

Nov 1, 1998

By Oliver Bowles

The exingencies of a world war have brought home to the American public, especially the people of the. Eastern States, the urgent need for conserving fuel. Transportation problems in the East have created an unprecedented situation wherein fuel-oil supplies are greatly restricted, and the consequent increase in demand for coal further complicates the problem of transporting and storing that commodity. People should awaken to the need for utilizing every possibly means of conserving to fuel, even to the extent of reducing the temperature in their homes.

Jan 1, 1942

By R. S. Dean

IN THE COURSE of its investigations directed toward providing strategic metals from domestic sources and toward utilizing power from Federal power projects in West, the Bureau of Mines concluded some years ago that the development of a method for producing electrolytic manganese might well be an important step towards both goals. Accordingly, laboratory investigations were undertaken in 1935. Further studied on a relatively large laboratory scale indicated that electrolytic manganese could be made from domestic ores at a cost not out of line with other nonferrous metals. On the basis of these results, the Electro Manganese Corp. Operating under U.S. Patent 2,119,560 issued to S, M, Shelton and assigned to the Secretary of the Interior for administration, undertook commercial production of electrolytic manganese at Knoxville, Tenn, This company has brought the process through the pilot-plant stage successfully, and is now regularly producing approximately one ton a day.

Jan 1, 1941

By L Mackinlay

The Apeketon Business Hub in Lihir, Papua New Guinea, emerged in 2019 through a partnership between Australian Business Volunteers (ABV) and Lihir Gold Limited (LGL), a subsidiary of Newmont Corporation. This development was driven by a shared vision for the Lihir gold mining operation to further enhance opportunities for the local community and strengthen the economy’s resilience post-mine. At its core, the business hub serves as the epicentre of ABV’s operations in the region. It includes a drop-in resource centre which provides the community with mentoring and consulting services, and access to a range of impactful workshops facilitated by ABV’s local staff and skilled volunteers. These workshops focus on local Lihirians but are open to the entire community, including Newmont employees. We design and continually refine Apeketon Business Hub support programs and offerings driven by community priorities, building trust through long-term relationships, and working side-by-side on real-time challenges. We offer three core programs to different levels of the community, from individuals and families to start-ups, large corporations, and landowner groups. There is significant demand for the support services provided by ABV, with over 350 Lihirians participating in our workshops over the 2023 calendar year. One of the hub’s core offerings is the Family Money Management Program, which addresses crucial challenges faced by Lihir households, particularly in terms of financial resilience. The program takes a comprehensive approach, assisting families in long-term planning and developing skills to effectively manage the income they derive from their employment with LGL and other enterprises. Significantly, the program also addresses financial stress, a factor often associated with domestic violence (Fox et al, 2002). By empowering women and promoting joint financial decision-making, the Family Money Management Program fosters a culture of savings and improved financial management, ultimately enhancing economic resilience within the community.

Sep 1, 2024

By M. Wu, A. Kharicha, A. Ludwig

"The droplet formation during melting of a 400 mm diameter electrode is simulated with a multiphase-MHD approach. The computational model includes a layer of slag and a layer of liquid steel. A VOF approach is used for the interface tracking and a potential formulation is used for the electric and the magnetic field. The Lorentz force and the Joule heating are recalculated at each time step in function of the phase distribution. The first results provided by this model are presented.IntroductionThe Electro-Slag-Remelting (ESR) process is an advanced technology for the production of components of e.g. high quality steels [ 1-9]. An alternating current (Figure 1) is passed from a conventionally melted and cast solid electrode through a layer of molten slag to the baseplate. Because of the electrical resistivity of the slag, Joule heating is generated and the slag transfers this energy to ingot and mould surfaces and to the melting electrode tip. The molten metal produced in the form of droplets passes through the slag and feeds a liquid pool from where directional solidification takes place. The slag and the ingot are contained in a water cooled copper mould. As also the baseplate is water cooled, a heat flow regime is imposed that gives controlled solidification, and this results in improved structure characteristics of ESR ingots.This process involves two liquids, a liquid metal and a liquid slag. Each liquid is subject to a phase change due to melting and/or solidification. From a fluid dynamic point of view, the ESR process is clearly a multiphase process, with free interfaces (slag/pool, gas/slag), and with a mixed area (slag and falling steel droplets) [ 10-15].Physically, the development of the heat and mass transfer at the slag/droplet interface is important for the final ingot quality, composition and cleanliness. Visual observations of the droplet formation just under the electrode being melted is almost impossible. Due to the presence of high temperatures, opacity of the materials, and the presence of the mould it is not possible to directly observe the behaviour the slag/pool interface. Although usually assumed flat [1-9], a previous work [10] using a Volume of fluid (VOF) model has shown that the interface shape between a layer of slag and steel layer in a cylindrical cavity is highly coupled with the distribution of the electric current. A full scale simulation of the ESR process using a VOF model has shown that the shape of the pool interface is likely to be non flat."

Jan 1, 2011

By Melvin P. Silverman

The literature on methane-oxidizing bacteria is reviewed in regard to (1) the growth and isolation of cultures by special techniques; (2) the distribution of these organisms in nature and descriptions of individual species; (3) the physiology of methane-oxidizing bacteria as influenced by temperature, light, pH, aerobiosis versus anaerobiosis, and carbon and nitrogen sources; and (4) the biochemistry of methane oxidation revealed by studies with intact cells and subcellular systems. Present practical applications of methane-oxidizing bacteria are limited to prospecting for natural gas and petroleum deposits. Desirable areas for future research are discussed as well as some possible applications such as (1) the removal and/or early detection of methane gas in coal mines by intact cells or enzyme preparations; (2) the generation of electrical energy by microbial fuel cells using methane as fuel; (3) the growth of methane-oxidizing bacteria on methane for their food value; (4) the purification of hydrocarbon gas mixtures using methane-oxidizing or other alkane-oxidizing bacteria; and (5) the synthesis of methane from mixtures of H2 and CO or H2 and CO2 by me thane-forming bacteria.

Jan 1, 1964

By P. D. Rao

The combination of high moisture and low heating value has restricted most low-rank coal (LRC) usage worldwide to mine-mouth power generation. Coals from Usibelli Coal Mine and the Beluga coal field have a heating value of approximately 8,000 Btu/lb and 28% moisture. Hydrothermal treatment (at 275 to 352'C) of lump coal from Usibelli Coal Mine and Beluga coal field enhanced the heating value of the coal, on an equilibrium moisture basis, from 8,000 Btu/lb to nearly 12,000 Btu/lb. The product coal with high heating value and 0.2 % S is an environmentally acceptable premium fuel. The Hardgrove grindability index of the coal is greatly improved, further enhancing its value. Increase in hydrothermal drying temperature promotes vesiculation of resinite. Vitrinite reflectance increased to 0.72 and vitrinite was subjected to widespread visiculation resulting in a coke like structure indicative that the material went through the fluid stage.

Jan 1, 1991

By S Casas Castellanos

"Tyres consumption is one of the costliest branches of the operation in a truck-based haulage mine. Off-the-road (OTR) tyres working within undesirable conditions have a considerable negative impact on the whole mine’s productivity. Only the rolling resistance due to underinflated tyres could increase truck fuel consumption by 15 per cent. The impact of other conditions such as road surface quality and temperature are difficult to estimate. Tyre management is a demanding activity that requires a high level of coordination between maintenance and production departments.The project is aimed to develop a smart decision tool to assist mine managers to optimise tyre resources. By identifying factors that have significant impact on tyres, managers are able to take timely action to mitigate undesirable working conditions.The proposed model utilises real-time tyre measurement of pressure, temperature, speed, load, deformation and surface profile to report tyre performance in terms of tonne-kilometre-per-hour (TKPH) and tyre longevity. Both indicators are permanently monitored in order to trigger a warning system designed to keep tyres under optimal working conditions.An interactive database ‘Octo-Mine’ wirelessly receives records from a programmable logic controller (PLC) deployed on the truck. PLC records are the integration of multiple sensor signals with a time stamp. Octo-Mine utilises real-time and historical tyre records to generate online performance and longevity reports, as well as preventative and corrective tyre maintenance scheduling, by comparing current tyre status with established standards.To validate the model, the prototype database was populated with hypothetical data to simulate ideal working conditions subject to comparison with real field observations. Additionally, a laser-based technology prototype device successfully measured a new 9 mm tyre tread and a 60 000 km rolled tyre tread in the laboratory.In conclusion, optimal tyre management contributes not only to reduction of tyre waste but also to truck energy efficiency. This project is a first step in proving these benefits under real field conditions. It suggests that further development of sensor equipment and its integration with a communication system is a worthwhile focus for future research.Citation:Casas Castellanos, S, 2016. Optimum Management of Truck Tyres in a Mine, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 212–228 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016