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By Fremont T. Johnson

Credited with production of more than 164,000 flasks Of quicksilver from 1876 to 1944, the Oat Hill mine has ranked third in output in the United States. During World War II, when the demand for mercury was high, this property was selected for diamond drill with the purpose of increasing ore reserves so that production could be maintained or, if necessary, increased. Although the existence of marginal-grade ore (fill material) left in the stapes and possibly of virgin ore of good grade had suspected in certain parts of the Oat Hill mine, no factual information to tonnage, grade, or location was available. In close cooperation with the Federal Geological Survey, the Bureau of Mines studied old records and the few available incomplete maps. Diamond drilling began in November 1943 and was completed in December 1944. Twenty-eight holes aggregating 8,121 feet were drilled, in only parts of the promising areas disclosed by the study of the data available. Detailed data on the work done by the Bureau as well as a brief history of the property and some operating details are described in this report.

Jan 1, 1949

By P J. Fairfield

This paper reflects on the author’s experience working in site-based technical and management roles over a 29 year period, and the past 12 years in internal and external consulting roles. It discusses the author’s experiences and observations of operations management, and the significant value of the technical specialist’s role in providing management with information on what to base tactical decisions, which may or may not be part of a defined strategy.The landscape of mine management changes with the cyclical nature of commodity prices driving operating and capital prudence, as operations change their focus from expansion and growth to staying in the game. The role of the mine manager and management team in navigating through these changing times, attitudes and stages of the project life can influence the success or otherwise of many projects.Technical knowledge is one of the key drivers in realising or destroying the value of a project or operation. As managers focus on people management, management systems and processes, recognising and understanding value in underlying technical knowledge, and getting back to the fundamentals/basics, can be overlooked. In reaction to the fluctuating commodity cycle, managers implement changes through optimisation, fast tracking or parallel streaming, expansion projects and changes in the application of technology. These responses occur against the background of changes in the appetite for risk, acceptance of project uncertainty and changes in personnel which result in a loss of knowledge and experience – often at critical times.This paper shares the author’s experiences and lessons learnt in dealing with and observing these issues. The author questions whether we really understand our projects and are valuing the most important asset, our people and, in particular, the technical specialist and their experience and knowledge.CITATION:Fairfield, P J, 2016. Staying in the game – the importance of engineering-based decisions, in Proceedings International Mine Management Conference, pp 67-74 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

By A. A. Shook

For relatively little capital outlay, the metal delivery control system in the BHP Copper Rod Plant at San Manuel' was significantly upgraded using the UNAC process simulation and control system (CICS Automation, Newcastle, Australia). An accurate simulation of the metal delivery process was developed with UNAC, which was then used to design a robust controller capable of dealing with plant complexities such as noise, time delays, and nonlinearities. This controller was implemented online using UNAC. Thanks to the extensive preparatory simulation, the controller worked immediately and required no additional online "tuning". Operator response has been favorable, and the UNAC control system has become part of the standard operation of the plant.

Jan 1, 1999

By John S. Anderson

The need for fuels and minerals in this country is estimated to double, triple, or even quadruple by the end of the present century. Even assuming more recycling of scrap metals and some priority allocation of energy, as has been done, for instance in war time, the projected increase in the nation's population and ever-increasing wants of that population will require vastly more minerals than are now being produced. Since mineral ores are being mined at lower grades, and since all minerals, including fuels, are having to be mined from deeper deposits, the amount of surface land to be disturbed will, inevitably, be increased. We cannot depend on foreign sources to supply all the extra requirements, since the non-U.S. population is increasing, in most cases, faster than our own. Furthermore, starting from a lower base, their mineral needs may accelerate more rapidly than ours. Restrictions on exports may be applied in foreign countries, if it appears that remaining reserves are not sufficient to fill the national needs. In vice; of the opposition which the mineral industry is receiving, as has been well described at these sessions and elsewhere, what can we, as mineral producers, anticipate as regards our ability to continue to operate, to sway nothing of expanding production? Although not minimizing the problems involved, it seems obvious that, except under emergency conditions, the country cannot tolerate a reduction in the available

Jan 1, 1971

By Sun Ying, Zhang Jing, Li Qiuju

A new process of enrichment Cu in molten copper slag under electric field is presented in this article. The experiments were carried out in the laboratory on a kilogram scale. The mobility of copper slag was improved by the technique of carbon reduction. The effects of temperature, electric field strength and intermittent feeding speed were investigated on Cu migration. The results showed that the best experimental conditions were the temperature at 1523K, electric field strength was 1.5V•cm-1 and feeding rates was 15 g•(10min)-1. The copper content of the slag decreased below 0.6wt%. The process was compared to the traditional electric furnace process of slag cleaning, there was reduced the energy consumption and heat loss, and also harmful gas emissions such as SO2 and CO2, accompanied by improved the efficiency of slag cleaning.

Jan 1, 2016

By K. M. Mohamed, I. B. Tulu

"Failures of coal ribs are major hazards in underground coal mines. For the period of 2010 to 2014, rib falls were the leading cause of groundfall fatalities and accounted for 35% of all groundfall-related fatalities. Currently, the National Institute for Occupational Safety and Health (NIOSH) is conducting a research project to develop an engineering-based design methodology for rib control in coal mines to reduce rib fall accidents and fatalities in underground coal mines. Numerical models can be used as part of the design methodology provided the models are appropriately calibrated and verified. The paper presents a coal rib model to simulate the mechanism of the coal deformation and fracturing that can lead to stress-driven rib falls. The proposed coal rib model was calibrated against published data from an instrumented rib site at the West Cliff mine in Australia. Fracturing of the coal rib was defined by critical values of shear strain of the coal material and rib displacement. A critical plastic shear strain of 2.8% and a sudden increase of rib displacement of 30 to 45 mm were sufficient to develop a fracture plane in the rib model. Accordingly, a discontinuous rib deformation was achieved and it compared favorably against field monitoring data. INTRODUCTION Coal ribs are the vertical walls of coal formed when entries are developed in a coal bed. Failures of coal ribs are a major hazard in underground coal mines. Furthermore, failing ribs can contribute indirectly to roof and floor instability by increasing opening widths across intersections and entryways. Over the last 18 years, there has been a continual occurrence of injuries and fatalities in underground coal mines due to rib falls. For the period of 2010 to 2014, rib falls (excluding longwall face and bursts) were the leading cause of ground fall fatalities and accounted for 35% of all groundfall-related fatalities [1]. Despite the threat of rib falls, the amount of rib falls and rib support research conducted in the U.S. is limited compared with what has been done in pillar and roof support design. Currently, the National Institute for Occupational Safety and Health (NIOSH) is conducting a research project to develop an engineering-based design methodology for rib control in coal mines to minimize the number of rib fall accidents and fatalities in underground coal mines."

Jan 1, 2016

By Hubert Bril, Priscilla Pareuil, François Bordas, Emmanuel Joussein, Jean-Claude Bollinger

"According to the legislation, valorization type, origin and characteristics of waste material, various standard procedures are available to evaluate environmental impacts. A Mn-rich slag was sampled from a metallurgical plant. After its characterization (elementary analysis and mineralogy), five standard procedures were carried out (i.e. TCLP, EN 12457-1). Each fixed parameter of the standards was systematically studied in a large range: pH, Liquid/Solid ratio, contact time. For example, EN 12457-1 led to a low ME mobilization, increasing with the L/S ratio, the contact time and an acidic pH. As a conclusion, the representativeness of the considered parameters and their potential variations are predominant to assess of the real environmental impact during slag reuse. Introduction Recent studies have been carried out about environmental impacts of waste containing metallic elements (ME) because of their potential mobility [1-7]. Indeed, slags are either dumped or valorized in various activities such as building materials. In order to assess environmental risk, various standard procedures are used depending on country legislation, origin of waste and valorization way. Results of leaching tests are linked either to special legislation (e.g. Dumping: EC, Council Decision 2003/33/EC, Construction products: EC, Council Directive 89/106/EEC) or to legal levels used in drinking water (Directive 98/83/CE) when leachates could migrate to groundwater. If ME in leachates are lower than drinking water authorized levels, the waste will be considered as non-hazardous. On the contrary, if the leachable amounts exceed them, the question about the risk has to be posed. Beyond the abundance of leaching tests available, variety of operational conditions induced by these regulatory tests does not make the choice easier. According to operational conditions induced, ME release could vary from one test to another one. ME concentrations in leachates depend on pH, Liquid/Solid ratio, contact time and particle size [3]. To highlight the importance of these operational parameters, potential risk for valorization of a manganese-rich slag was assessed by comparing several standard leaching protocols [8-12] with a global study dealing with the influence of operational conditions. For each regulatory protocol, the most influential parameters (L/S ratio, pH, particle size and contact time) have been studied in a large range."

Jan 1, 2008

By Jack L. Woodward

The evolution of surface mining equipment has resulted in larger, faster haulage units, loaders, etc., resulting in increased demands on steering technology. Careful analysis of these systems was warranted to determine if steering-related safety problems have been introduced. The objectives of this program were to: 1. Define the generic types of steering systems being used on mobile mining equipment used in surface mining operations. 2. Gather information on steering-related accidents in mining operations. 3. Assess the need for initiating government-sponsored research into steering system technology. A comprehensive literature survey was conducted concurrent with extensive contacts with mining operations, mining equipment manufacturers, steering system component manufacturers, and government agencies. A Technical Evaluation Group composed of representatives from the above organizations was formed to review the data gathered. It was concluded that the steering systems in use on surface mining equipment are reliable and do not present a safety problem. The Society of Automotive Engineers, Inc. is active in pre-paring voluntary consensus standards to assure that the minimum levels of performance are defined for industry.

Jan 1, 1979

By S. L. Bessinger

The need for improved safety and productivity brought about the introduction of longwall mining to the Appalachian coal fields. These same forces continue to drive developments in modern longwall equipment and mining practices. Current initiatives to improve productivity and safety are focused on automation and the effects of scale in equipment design. Longwall roof-supports, shearers and face-conveyors have changed significantly. Panel layouts have evolved to include larger total tonnages and provide for more rapid development of gate-entries. These advancements have improved longwall productivity and new production records are continually being set. Roof supports Reliability is implicit in the quest for automation. It is impossible to automate equipment if it is not reliable. To a large degree, this has been the problem with longwall shield automation efforts. The "electronic control" of shields depends on the proper functioning of electronic equipment, electrohydraulic valves and full-flow service valves onboard every support.

Jan 1, 1995

By Y. Kashiwaya, J. Yagi, P. R. Austin

The problems of global environment and resources have become important issues in recent years, and the iron and steelmaking industry is requested to decrease energy consumption and carbon dioxide emission. The improvement of efficiency of ironmaking system is one of the countermeasures for these problems because more than a half of total energy input to the integrated steelwork is input to the ironmaking system. Various approaches to improve the blast furnace process have been made. The authors examined their performances through mathematical simulations of blast furnace operation, and confirmed the improvement of blast furnace efficiency under some operating conditions. The ironmaking system consists of various processes, and the materials and the energy are transported among these processes. Thus it is necessary to evaluate the efficiency of the novel operation of blast furnace based on the ironmaking system. In this study, the balances of material and energy on ironmaking system that consists of blast furnace, coke oven, sintering and hot stove processes were analyzed. The operation status of each process in the system was adjusted according to the results of the operation simulation of the blast furnace under novel operating conditions. The analysis clarified the effect of the blast furnace operation on the energy balance and CO2 emission of the ironmaking system.

Jan 1, 2015

By Marco Le Roux, Martha Van Rensburg, Quentin Campbell

Fluidised bed drying is currently receiving much attention as a dewatering option during the beneficiation of fine (defined here as between 1 mm and 2 mm particles) coal. Apart from concerns about safety and combustion, the operating costs can be high if very high gas or air temperatures are used. The aim of this study was to investigate the removal of moisture from fine coal by using air at a lower temperature (25 - 55°C) within a controlled environment by lowering of the relative humidity of the air. It was firstly proven that fluidization has a major advantage over non-fluidized beds, with regards to drying rate and final moisture content. Hereafter several parameters that influence the dewatering rate and final moisture content were tested, from which it was concluded that the relative humidity of air acts as the largest driving force for dewatering. Parameters tested included relative humidity, temperature and coal composition. Energy balances showed a positive nett energy increase in the dried coal during combustion when related to the energy input during drying. In comparison with thermal drying technologies, fluidized bed drying was proven to be less energy intensive. It was therefore shown that this is a viable technology for the dewatering of fine coal.

Jan 1, 2014

By C. Opoku-Ware, M. Kukay, P. Conrad

"This project is exploring the potential for developing trees tolerable to degraded un-reclaimed mine site soils and tailings as a solution to re-establishing long-term tree growth on those sites. The project incorporates growing tree seedlings in an underground greenhouse grown from seeds planted in the degraded mine soils in which they will eventually be planted. The outcome of the project is expected to lead to a successful solution for re-establishing tree growth in soils and tailings containing high metal concentrations with minimal post-planting human intervention. The research is being conducted in an underground greenhouse located 100 feet below the surface in the old Orphan Boy Mine Underground Mine Education Center (UMEC) located on Montana Tech’s campus in Butte, Montana. INTRODUCTION In an effort to improve Butte Area One natural resources, the research project was proposed to help restore tree growth in the Butte Priority Soils Operable Unit Boundary (BPSOU). Research by Blicker, et al. (2003) found that, the BPSOU, which is part of the Silver Bow Creek/Butte Area National Priorities List (Superfund) Site within and near Butte, Montana has multiple historic mining sites situated entirely within the urban setting of Butte. Mine wastes and mill tailings, accumulated from over 100 years of gold, silver, and especially copper mining are dispersed throughout Butte, posing health risks to human and environmental receptors. Stabilization of tailings sites is needed to control fugitive dust, prevent run-off of toxic material resulting in subsequent sediment deposition in streams, reducing the volume of water seepage through acidic and heavy metal contaminated material, and improving land productivity and aesthetic VALUES ((Watkin and Watkin, 1982). If successful, the project will help restore water quality and maintain stream flow in Silver Bow Creek where it flows through Butte Area One. Trees native to Butte are being grown in an underground greenhouse located in the UMEC and will be planted in five areas located within the BPSOU designated for tree planting by the Butte Silver Bow government. Growing trees is expected to help restore vegetative ground cover within the watershed contributing to stream flow in Silver Bow Creek. They will prevent soil and tailings from eroding and being deposited in Silver Bow Creek where they could degrade water quality and choke stream flow."

Jan 1, 2018

By J. G. Donaldson

Cobalt-tungsten binary deposits were formed in laboratory experiments by hydrogen reduction of the anhydrous mixed vapors of cobaltous chloride and tungsten hexachloride. The materials were sublimed in seperately heated zones of reaction tube and were transported in a stream of purified helium into the deposition section of the tube where the chloride gases were reduced to metal by a countercurrent flow of hydrogen. Heattreating of the near stoichiometric binary metallic deposits converted nearly all to the intermetallic compound Co3W, however, small quantities of both cobalt and tungsten remained. Mechanical tests showed that the tensile strength of heat-treated 75 percent cobalt-25 percent tungsten deposits was twice as high as that of similarly treated deposits of cobalt.

Jan 1, 1965

By S G. Bergdahl

Underground mining in Sweden is today characterized by mechanization and automation, owing to the rising cost of labour. Drilling in drifts and tunnels is still essentially done with jackleg drills, but rigs wh1ch make it possible for one man to operate two or more drills are now frequently used. Large jumbos for longhole drilling, with two drills operated by one man, are used, especially in sub-level caving. A special drill-rig for drilling through overburden and blasting without removing the overburden has been successfully used in canals and also in ports, where blasting is per-formed under water. The increased use of mining methods based upon long blastholes is a result of the development of equipment for drilling long straight holes. The most common mining method in Sweden is sub-level caving. Extensive research, with model tests, has been carried out in order to determine suit-able dimensions of drifts, sub-levels and drilling patterns. The results have been tried in practice and have given increased yield and less waste rock in hoisted ore.

Jan 1, 1963

By Edward G. Cunney

Track in underground bituminous coal mines was investigated and technology was taken from other industries in order to obtain information on conditions that impair the safety and efficiency of the track and to develop guidelines and useful information on the construction, inspection and maintenance of mine track. Volume 1 contains information on the investigations, observed track conditions, useful technology from railroads and other industries, derivations of track condition descriptors and limits, conclusions, and recommendations. Volume 2, Guidelines, contains recommended standards and practices for mine track. It includes the relation of track conditions to safe speeds; descriptions and limits for measurable track features, such as gage; descriptions of conditions for track components that are normally not measurable, such as subbase soils; construction requirements and techniques; inspection requirements and methods; and methods for managing and performing track maintenance work. It does not repeat the summary or? derivations. Volume 3, Inspection Handbook, summarizes recommended standards and procedures from Volume II and provides related information for ready reference by inspectors in the mines. As a research product to be used in mines, it does not repeat the summary, derivations or references.

Jan 1, 1977

By Beverly W. Dunning

The effect of vacuum melting on the elimination of gases and nonmetallic inclusions for six low-alloy steels was investigated. The purpose of these studies was the analysis and comparison of differences in gas content and inclusions in air-melted and vacuum-melted steel. Data obtained from melts of 1-1/4 to 20 pounds indicate that vacuum melting decreases the number and size of nonmetallic inclusions and at the same time increases the degree of dispersion of the remaining inclusions. These improvements are undoubtedly related to the elimination of approximately 80 percent of the nitrogen and 90 percent of the oxygen as well as most of the undesirable metallic trace impurities.

Jan 1, 1961

By L. K. Weaver

Bureau of Mines investigated the progressive impact that petroleum (crude oil and condensate) operations in the Gulf of Mexico have had on onshore operations and the expected effect of increasing activities in this area on future petroleum supplies from domestic sources. The data analyzed include capital expenditures, number of wells drilled, success ratio for exploratory wells, daily production per completion, annual producing rates, and oil reserves. The report compares offshore and onshore data and ascertains trends in petroleum industry operations. Observed data and trends indicate that in the near future Gulf of Mexico development and production will continue to increase relative to total U.S. petroleum activity. By 1975 annual oil and condensate production from the Gulf of Mexico is expected to be in the range of 750 million bbl to 1,150 million bbl, and account for approximately 20 to 30 pct of the estimated total domestic production.

Jan 1, 1969

By Thomas. Lisa, Mark Coleman

Schenck Process is an established customer-driven solutions provider, utilising its knowledge, expertise and technologies to transform production processes. Operating across several industries Schenck Process have developed quality solutions from their range of equipment to solve problems and fill holes in other people’s processes. In the non-ferrous metals industries Schenck Process have been using their Clyde Brand solutions in Pneumatic Transport to solve problems on smelter sites for a number of years, handling of concentrates, additives and metallurgical dusts. Working alongside clients around the world they have developed a number of dust handling systems for flash furnaces from New Boliden, through Codelco to PASAR. Solving handling issues in dust collection has proved to suit Schenck Process range of equipment well and now a series of solutions are available. Solutions have been developed to handle materials up to 600°C and can convey over 1 km. Conveying to remote location for disposal, injecting directly into a furnace through lances, return to furnace burner feed, or deliver and dose into leaching reactors, Schenck Process are ready to ‘make processes work’. Historic solutions at New Boliden and Codelco demonstrate a range of material application and the long term performance of the equipment. Recent installations at Pasar utilise the Schenck new ProPhaseTM equipment and handle the Waste Heat Boiler and ESP dusts directly and simplify the dust train. The paper will seek to show how this equipment can bring benefit in handling high temperature materials directly and eliminate several traditional steps that are often unreliable. The systems can be paired with Schenck Process new PHASiQTM and STREAMiQTM control systems which are complete PC, HMI, PLC, Interface system with full SCADA, Data Storage and IoT ready remote interrogation and support available. Installed in this challenging environment the systems are ready for smelter use. The systems can be also joined to our new E-nizingTM web portal. A perfect partnership to deliver the trend in ‘Big Data’ while providing visibility and off site support. The paper will show how these systems can deliver reliable equipment and remote support for these often isolated sites as well as delivering rapid return on investment. This paper discusses a step change in simplifying Flash Furnace Dust handling which Schenck believes shows the truth of Schenck Process Solutions claim that ‘we make processes work’.

Jan 1, 2019

By Douglas Glenn Stalheim

Production of structural steel with a minimum yield strength of 700 Mpa produced as hot rolled coil has become increasingly popular due to cost considerations when compared to quench and temper equivalent product. This grade when produced as hot rolled coil requires the use of microalloy precipitation strengthening mechanisms. This is typically a combination of niobium and titanium microalloys. While the metallurgical concept of structural steel precipitation strengthening mechanisms has been well researched and published, actual implementation into the production process can be very challenging. In addition to achieving a minimum yield strength of 700 Mpa, in many applications additional mechanical property attributes of formability as measured by hole expansion testing along with low temperature toughness properties are now required. Achieving a balance of all the mechanical properties in a stable and repeatable performance in production using microalloy precipitation strengthening mechanisms further increases the challenges. This paper will discuss the metallurgical/process strategies required to successfully produce 700 Mpa minimum yield strength hot rolled structural steel coil. In addition, the role and goals of both niobium and titanium in this product design will be presented.

Oct 30, 2017

By J. A. Herrick

Jan 1, 1879