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By L. Tikasz

The primary purpose of ore hauling model studies is to capture the variability of the ore delivery ? stockpiling process in order to improve the estimation of equipment capacities and achievable throughputs. The operation of a mine-to-site ore delivery system is the subject of a number of challenges. Typically, ore is hauled by a given combination of trucks, conveyors and trains. In addition, ore loading, ore transferring to another means of delivery, stockpiling, reclaiming, and further deliveries involve many other types of equipment. The concurrent operation of all these units is scheduled; nevertheless, they are subject to planned maintenance and random breakdowns. To support our engineering design work on ore hauling operation, discrete event type models were built for each specific task. Then, due to recurring demands, an ore hauling library was gradually compiled. The now available model library allows fast and efficient simulation of various mine-to-site hauling arrangement, adaptable to various mining and mine construction operations (e.g. bauxite, iron ore, copper ore and coal).

Aug 1, 2013

By John W. Hughes

During the course of any truck loading operation, it will become necessary to replace hauling and loading units. Timing of replacement can be selected on the basis of necessity, or guesswork, or on a schedule derived from past performance records. Replacing units too soon results in high capital costs per hour. Waiting too long results in high maintenance costs per hour. As with any phase of a mining operation, a planned schedule can reduce overall costs and keep breakdowns within reason.

Jan 10, 1976

By K. C. Dean

During the course of the investigation of manganese mineral occurrences in the western United States, the Bureau of Mines collected several lots of ore' from properties in the vicinity of Winkelman, Ariz. As none of the ores would be marketable directly, an investigation was made to determine their amenability to concentration by ore dressing. The Geronimo group of claims is in Pinal County, 8 miles west of Winkelman, Ariz. The manganese oxides occur as cementing material in ore zones of conglomerate. Representative samples of a 2-ton lot of ore cut from outcrops of two lenticular deposits were laboratory-tested. Two 1-ton samples from the Benningfield property were similar in physical characteristics but differed in grade. This claim is 11-1/2 miles south of Winkelman and about 1 mile west of the San Pedro River on the south side of Putman, Wash. The manganese minerals occurred as nodules and lenses, replacing limestone, in a capping over a dark, igneous dike. The North Star group consists of five claims on the west side of the San Pedro River 14 miles south of Winkelman. The ore consists of a low-grade, manganese oxide-calcite occurrence interspersed with stringers of higher-grade material and is present as filling in a fissure zone in porphyry. Two samples were obtained by the examining engineer; one sample represented run-of-mine material, the other represented ore from the vein that could be hand-sorted or selectively mined.

Jan 1, 1952

The SFR system utilizes a skimmer or extractor placed at or near the slurry-froth interface where there is a higher concentration of valuable mineral particles. With assistance of hydrocyclones, it is possible to classify the extracted particles into coarse and fine particle streams, that can be handled separately. It also allows the coarser solids to be separated from entrained low-value fines. The first test results with the SFR system significantly improved both coarse and fine particle recovery in a flotation cell. The SFR system was tested in the flotation circuit at a copper-moly concentrator, and the results show that the use of the skimmer has huge potential to increase the froth recovery (Rf) of both molybdenum and copper.

Jan 1, 2012

By G. E. S. Lima, J. V. B. Lemes, F. G. D. Machado, J. Alexandre, L. G. Pedroti, L. A. F. Fioresi, W. E. H. Fernandes, R. C. S. S. Alvarenga

Cellulose fibers are extracted from renewable sources and have potential to be used in various fields. In this study, a type of Reactive Powder Concrete (RPC) was produced with the addition of Cellulose Nanofibers (CNF), a biopolymer extracted from lignocellulosic materials. Three different concrete compositions were produced, each with addition of 0.10, 0.20 and 0.25% of CNF in mass, proportionally to the cement’s mass. During the analysis were performed Scanning Electron Microscopic (SEM) tests, compressive strength and Young’s modulus tests after 1, 3, 7 and 28 days of production and shear and flexural strength after 28 days of production. The results showed that the addition of CNF in aqueous solution reduces the concrete’s workability and negatively affects mechanical properties.

Mar 1, 2017

By D. A. Peterson

A research program is currently in progress at the University of British Columbia to determine the potential of composite cable bolt reinforcement in Canadian mines. Several prototypes of glass fibre cable bolts have been tested. Their evaluation consisted of lab testing at the University of British Columbia, United States Bureau of Mines (Spokane) and trial installations at Detour Lake, Winston Lake, and Myra Falls Mines. A market analysis of cable bolts within the Canadian mining industry has been completed. Fibre reinforced polymer composites have a high potential as cable bolt reinforcement in mining applications. They prove to be a viable alternative to steel cable bolting.

Jan 1, 1993

By Gene Asai

The Bureau of Mines investigated the caustic extraction of alumina and soda from retorted dawsonite-bearing oil shale, as part of a program to devise technology for treating alternative domestic sources of alumina for the production of aluminum metal. Colorado oil shale yielding 13 pct oil (35 gal/ton) and containing 12 wt-pct dawsonite (representing about 4 pct extractable alumina) was retorted to obtain oil-free (spent) shale Spent shale was leached with dilute NaOH to determine the effect of particle size, retorting temperature, leaching variables, and storage conditions on extraction of alumina and soda and dissolution of impurities. Maximum alumina and soda extractions were obtained by promptly leaching minus 28-mesh spent shale, obtained by retorting raw shale at about 5000 C, with 0.5N NaOH. Under these conditions, dissolution of impurities such as Ca, Fe, Ti, and P was low. Leaching tests were made on spent shale stored for periods of up to 30 days at 0° to 42° C and at 0 to 100 pct relative humidity (RH). These tests indicated that significant reductions in alumina extraction would occur if spent shale were stored in ambient Colorado air under naturally fluctuating temperature and humidity.

Jan 1, 1983

By R Dunne, S Hart, G Levay

While water represents a major proportion of the mineral pulp processed in flotation circuits, relatively little research effort has been committed to understanding and controlling the influence of water quality on this process. Historically, this probably stems from the perception of water as an inert transport medium. However, the changing attitude towards water as a valuable resource, has given impetus to increasing requirements to use relatively impure make-up water supplies such as treated effluents and a high proportion of internally recycled water. In turn, this has resulted in the need for a more detailed focus on process water quality and its control to minimise adverse effects on sulfide flotation. Along these lines, prior to commissioning of a new concentrator at their Cadia Hill Gold Mine, Newcrest Mining was proactive in examining potential water sources and the influence of water quality on flotation of their copper/gold bearing ore. An extensive water quality survey of all major potential water supplies to the concentrator was undertaken. The flotation performance of the Cadia ore in each of these waters was investigated on a laboratory scale. The results of these studies identified that water quality could indeed have a significant influence on the flotation process. Since operations at the Cadia Hill concentrator began, water quality surveys of both make-up water sources and recycled flotation circuit waters have been carried out on a regular basis. By doing this, a database of water quality has been established which can be compared with plant performance. In parallel with the water quality surveys, a series of laboratory flotation tests have been conducted using a standard ore and waters from various streams to monitor changes in flotation performance as a function of water quality. These tests have indicated that certain water types may have a significant influence on plant performance. More research is required to better understand the impact of water quality on sulfide flotation. This understanding will help operators to minimise adverse effects, while maintaining the best utilisation of available water resources.

Jan 1, 2003

By Vernon F. Swanson

Several laboratory flotation tests were conducted by the Bureau of Mines on a sample of unweathered diorite from the B. F. Camden property, Amherst County, Va. Results showed that an ilmenite concentrate analyzing 45.5 percent Ti02 (titania), 0.07 percent P205 (phosphorus pentoxide), and 2.21 percent Si02 (silicon dioxide) could be produced from a feed containing 7.72 percent Ti02 and 3.94 percent P205. Ti02 recovery in the concentrate was 47.6 percent in a batch test. The weathered saprolite material overlying the diorite required scrubbing and desliming to remove argillaceous material and preliminary flotation of apatite followed by flotation of ilmenite. The resulting concentrate analyzed 47.3 percent Ti02, 0.19 percent P205, and 0.99 percent Si02 from a starting feed of 8.99 percent Ti02 and 3.37 percent P205; TiO2 recovery was 54.5 percent.

Jan 1, 1963

By K. Lang

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

Sep 1, 2013

By E. Stone, R. Reagan

Risk of hand injury is very real for operators carrying out conventional bolting operations with power torque tools, reaction arms and backup wrenches. Bolting operations of this type are common today in the installation and maintenance of heavy mining machinery and equipment. Newer solutions have become available that have the potential to dramatically reduce the risk of hand injuries in mining applications. MINING APPLICATIONS Within the scope of mining operations, various types of equipment are used such as tunnel boring machines, bucket wheel excavators, draglines, material handlers, screens, pumps, crushers, continuous miners and longwall systems. Design of these machines typically includes larger diameter bolts for strength and durability. Due to rugged use all machines require frequent maintenance and service which requires the use of heavy industrial bolting tools and methods. Those engaged in bolting operations include technicians working for end-users, equipment manufacturers, general contractors and others who provide services in mining operations. Most all personnel involved with these activities are engaged with use of high power bolting tools and procedures. Training is essential to raise the awareness of bolting safety and to avoid accidents. However improved bolting tools and procedures can play an even more significant role in further improving the safety of all those engaged with bolting in the mining industry. SAFETY CONCERNS Professionals working in the mining industry are constantly looking for ways to further reduce risk to health and safety. Bolting operations which are fundamental to service and maintenance of mining equipment are often overlooked as a potential area for improvement. Several areas of bolting operations offer potential for improvement in safety and avoiding accidents during equipment maintenance. This paper addresses the safety concerns associated with reaction arms and backup wrenches in conventional bolting applications (Figure 1).

Jan 1, 2019

By L. Deininger

The QSL plant in the existing "Betzelius" Stolberg GmbH lead smelter in StolberglGermany was commissioned in August, 1990. Following some modifications to the process and equipment which had become necessary in line with the implementation of this new techno- logy, conclusive operating results are now available. These will be reported together with a short description of the plant design. In May 1992, raw material feeding to the QSL reactor in the new lead smelter of Korea Zinc Co. in OnsanlKorea was started. As all the experience gained up to that point in time in the Stolberg plant had already been incorporated in this plant prior to start-up, it reached stable, satisfactory operating conditions in a short period of time. After an introductory description of the plant important operating results will be reported. The operating experience gained in the two plants fully confirms the correctness of the in- ventors' creative ideas in the 70s. The QSL process meets all demands made on modern, ecologically compatible and energy-saving lead production technology. The paper ends with suggestions on how the QSL process will be optimized further in the future.

Jan 1, 1994

By W. L. Acherman

Molybdenum, tungsten, and vanadium were found by the Bureau of Mines to possess generally superior chemical and galvanic corrosion properties in many aqueous corrosive media at temperatures up to the boiling point. The corrosion resistance of vanadium in certain solutions was further improved by alloying it with such metals as columbium, tantalum, and titanium. was susceptible to a type of crevice corrosion in mercuric chloride solutions, but no other instances of crevice corrosion were encountered. With few exceptions, molybdenum, tungsten, and vanadium were not adversely affected when coupled with dissimilar metals in galvanic corrosion experiments; in some cases one or both members of a couple were protected by contact. When exposed to aqueous ammonia spray at 60° C, all three metals were attacked, but they were moderately resistant in spray environments of substitute ocean water and ammonium dihydrogen phosphate.

Jan 1, 1966

By Gerald G. Johnson

The use of the Scanning Electron Microscope to characterize Coal Mine Dust has been possible because of two circumstances. First, the imaging process of the SEM allows multiple signals (secondary electrons, back scattered electrons, x-ray emission, etc.) to be viewed. Second, the use of a computer to analyze the signals and perform statistical tests on the results. The parameters described are size, shape, chemical composition, mass distributions, and particle thickness. Although the system is intended for particular systems, those of agglomerates (whether tile same or not) are handled by special aspects of the computer programs. The work on fibers is not completed at the time of this report. This work discusses the hardware (developed especially for this process) and software (both on an IBM 360/370 and a PDP 11/20). The latter system allows direct interaction between the operator of the SEM and computer for maximum information at the least time.

Jan 1, 1979

By S F. Rogers, P W. Booth

Digital photogrammetry is revolutionising the task of geotechnical mapping of jointed rock masses and has greatly increased in popularity and sophistication in recent years. Modern commercially available digital photogrammetry software systems can provide geotechnical practitioners with a user friendly tool for rapid data acquisition. The data can be acquired remotely from large exposure areas, some of which may be otherwise out of reach due to restrictions on time, access or safety.Photogrammetry is a complimentary technology to discrete fracture network (DFN) modelling because it can provide the large, statistically significant, spatially located geotechnical data sets required to produce the most robust results. It also provides the flexibility to selectively map structures at a range of scales, depending on the focus of the DFN modelling.Integration of the interpreted rock structure data derived from photogrammetry with modern DFN modelling methods really advances the rock engineering process. The ability to generate 3D fracture models driven by the statistical structural data and conditioned to the features observed by the photogrammetry yields a synthetic rock mass on which improved design methods can be applied. The generation of multiple equi-probable conditioned DFN models allows the use of probabilistic methods for assessing kinematic stability, rock block size distribution as well as a range of other applications.CITATION:Rogers, S F and Booth, P W, 2014. Integrated photogrammetry and discrete fracture network modelling for improved rock mass characterisation and engineering design, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 203–208 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Bogidar Mihaylov

A laboratory study was conducted on continuous precipitation of copper, cadmium, mercury and arsenic using thiourea, thioacetamide, sodium sulfide and ammonium sulfide as precipitating agents. Depending on the experimental conditions the metals precipitate with the sulfide donors at different orders and rates. These differences were employed as a basis of several techniques for continuous separation of copper and arsenic, cadmium and arsenic, mercury and copper, and copper, mercury and arsenic. The separation of the metals from industrial waste solutions was also studied. The precipitates obtained were inspected using x-ray diffraction, scanning electron microscope, atomic absorption spectrometer and plasma particle counter.

Jan 1, 1992

By Dale A. Shay, Roy R. Cellan

The Santa Fe Mine, located in west central Nevada, began leaching ore in 1988 and completed ore processing in 1995. Homestake Mining Company has completed final reclamation of the site, including remediation of bare surface soils resulting from the oxidation of sulfide minerals and migration of acidity in the mine waste repositories. The need to remediate oxidized sulfides and mitigate resultant acidity at the Santa Fe Mine emphasizes the economic, reclamation, and environmental advantages for understanding and pre-planning for management of potential sulfide wastes during mine planning phases. The lack of pre-planning by mining companies for sulfide waste management was common in the 1980's due primarily to mining of reserves characterized largely as oxide deposits and to the common opinion that low moisture regimes in arid or semi- arid climates would not allow for significant acid generation. Since the 1980's, operational experience has shown that sulfide wastes, deposited randomly in waste dumps and without adequate planning for final reclamation success, can create final reclamation problems that are very costly to remediate. While mine waste characterization, waste management plan compilation, and in-pit selective waste handling procedures add operational costs, the reclamation experiences at the Santa Fe Mine are indicative that pre-planning and management is worthwhile both in actual overall cost efficiency and in successful reclamation of the mine site. The reclamation program at the Santa Fe Mine shows Homestake's continued commitment to the successful management and reclamation of their mine sites.

Jan 1, 2000

By C. L. Kosmoski

In recent years, coal mining safety has attained national attention due to several highly publicized disasters. Despite these threats to worker safety and health, the U.S. relies on the mining of coal to meet its need for electrical power, with 42% of electricity in the U.S. generated through the burning of coal (U.S. Energy Information Administration, 2012b; United Mine Workers of America, n.d.). Furthermore, the production of coal continues to increase and reach record levels every year (National Mining Association, 2012; U.S. Energy Information Administration, 2012a). For this reason, the coal mining industry must continue to find ways to protect its workers while maintaining productivity. One potential approach to protecting workers while maintaining productivity is through improving the safety culture at coal mines. In order to achieve this culture, operators, employees, the inspectorate, etc. must share a fundamental commitment to safety as a value. This type of culture is known in other industries as a ?safety culture,? and can be defined as the characteristics of the work environment (such as the norms, rules, and common understandings) that influence facility personnel?s perceptions of the importance that the organization places on safety. Fundamental to improving safety culture within an organization is understanding the existing safety culture; improvements cannot be made without first elucidating areas that require improvement. This manuscript details the process undertaken by researchers at the National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) to assess the safety culture at five underground coal mines across the United States. The purpose of this manuscript is to present the aggregated results from those five safety culture assessments conducted at underground coal mines. Additionally, some general recommendations for areas where coal mines might focus their attention as part of their attempts to improve safety culture are offered.

Feb 23, 2014

By H. F. Beardmore

PETROLEUM consumption during 1946 broke all previous records and further increases are expected during 1947. U. S. consumption amounted to an average of 5,280,000 bbl a day, of which 4,745,000 bbl was domestic crude oil, with the rest from natural gasoline production and crude oil imports. World consumption during the past year, excluding Russia, is estimated at 7,200,000 bbl daily. Forecasts for 1947 indicate a U. S. consumption of 5,425,000 bbl daily of petroleum products. This is expected to be made up of 4,655,000 bbl of domestic crude oil production, 340,000 bbl of natural gasoline production, 400,000 bbl of crude oil imports, and the rest from stocks. Petroleum's principal use is still as a fuel. The field remains highly competitive, but petroleum has been continuously progressing. Less than fifty years ago, oil supplied only one twentieth as much of the nation's total energy as coal, but today it supplies over half as much.

Jan 1, 1947

By Mritunjoy Sengupta

The Green River formations in the Western U.S.A. contains vast amounts of petroleum reserves in oil shale deposits. Exploitation of this petroleum reserve calls for large scale mining of the oil shale. Applicable mining methods include conventional underground mining using roan and pillar, sub-level caving and block caving; underground insitu retorting of oil shale and open pit mining. Roam and pillar mining offers one of the most economic methods of underground mining of oil shale. A 2.4 x l09 litre per year (50,000 barrels per day) of crude oil production would require a daily oil shale production of 100,000 tomes per day from underground operations. For this large production, a highly mechanized room and pillar mining muld utilize large capacity diesel equipment such as 85 tonne trucks and 8m front end loaders. The total air requirements of an oil shale mining operations can. be as high as 28443/s. Ventilation planning for such a large scale underground mining operation presents a formidable task. The major objectives of providing ventilation air to underground workings are to dilute airborne .dust and diesel fumes to harmless levels, and to insure that the mine environment is compatible with the health and safety of mine personnel. Regulation of air velocities and air temperatures is a major factor in mine environmental control. Colorado State law requires that a minimum of 0.047m3/s of fresh air be supplied for each kW of diesel power operating underground. Additionally, 0.047m3/s of fresh air must be supplied for each underground employee, and a minimum air velocity of 0.15m/s must be maintained in all working places. It is desirable to exceed this minimum velocity in order to prevent stratification of ventilation air. Moreover, Colorado law also stipulates the maximum allowable concentration of noxious gases mine air, below: ? C02 - 0.5% by volume, 5,000 ppm. ? CO - 0.005% by volume, 50 ppm. ? Oxides of Nitrogen - 0.0025% by volume, 25ppm. ? Nitrogen Dioxide 0.005% by volume, 5 ppm. This paper examines ventilation requirements for the underground mine, with respect to air quality requirements and distribution of air in mine workings in light of the above regulations. Analyses were made for sane typical mining plans to determine airflow resistance or pressure drops and fan horsepower requirements. In addition, the possible occurrence of high concentrations of toxic gases, was examined. Expected temperature levels in mine workings were approximated.

Jan 1, 1980