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By Rob Domotor

This paper tells the story of using controlled surface and underground blasting methods to excavate hard rock in three areas on Australia’s largest road infrastructure project; the Airportlink Project in Brisbane; worth a total value of AUD $4.8 billion. The project used blasting methods including design, modelling, drilling and loading of the explosives that had never been used before in Australia, some of these were probably unique in the world.

Jan 1, 2012

By Joseph D. Davis, GEORGE S. POPE

This bulletin is the fourth of a series a showing the results of the purchase of coal by the Government under specifications. The work of inspecting and analyzing coal delivered on Government contracts was transferred to the Bureau of Mines by an act of Congress effective July 1, 1910. It had been carried on for several years before that date by the technologic branch of the United States Geological Survey. The purchase of coal on the dealer's statement as to quality or on the reputation of the mine or district producing the coal is gradually being discontinued. At present most coal-purchasing contracts make definite provision regarding the desired heating value of a coal and the composition as shown by analysis. The heating value is usually expressed in British thermal units" and the composition specified is that shown by proximate" analysis. The price to be paid for delivered coal is made to depend on whether the analyses and heating-value tests of samples representing the delivery show the quality to be above or below the quality set forth in the contract. Large coal consumers are beginning to appreciate more and more the importance of the cost of power as a factor in the cost of producing a finished article. The endeavor to increase the efficiency and the economical operation of a power plant calls for an intimate knowledge of the quality of the coal being used. The purchase of coal under specifications insures the purchaser getting what he pays for and the coal being of the quality guaranteed. In addition, the analyses and tests of the delivered coal furnish data whereby the power-plant results can be comprehensively studied and a continuous check maintained on the conditions of operation.

Jan 1, 1912

By L Edwards, M Haest, D Mittrup

The focus in the iron ore industry has shifted from increasing production volumes with less regard for cost, to efficient production of quality tonnes. BHP Billiton iron ore geoscience and exploration has embedded infrared spectroscopic sensing of drill hole samples to help meet this challenge.Infrared spectroscopy is delivering mineral predictions that are used for (automated) geology logging and modelling. The spectra are processed together with other available data sets to predict geometallurgical and geotechnical variables that include lump per cent and uniaxial compressive strength.Trials are ongoing to test the benefit of infrared spectroscopy during mining, including the analysis of grade control samples and remote sensing of mine faces. Results show great benefits in the fields of short-term geology modelling, better understanding of material (handling) properties, identification of geotechnical risk areas and high resolution ore-waste delineation.These trials are bringing BHP Billiton iron ore closer to its ultimate goal of having infrared spectroscopic data collected across the mining value chain. Once such data are available everywhere, regression models can be trained at one point (eg iron grade model trained on exploration samples) and be applied elsewhere (eg iron grade predicted on mine faces). Such predictive analytics will enable not only high precision mining, but also provide maximum time to tailor plant design to the ore in the ground, based on learnings from ores processed in other plants. This will improve planning outputs that will eventually increase mining efficiency, processing capability and product quality.CITATION:Haest, M, Mittrup, D and Edwards, L, 2017. Infrared spectroscopy in BHP Billiton iron ore with a focus on in-mine infrared sensing, in Proceedings Iron Ore 2017, pp 549–556 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Charles V. Jude

This U.S. Bureau of Mines report presents a review and evaluation of existing and new backfilling materials and methods for their applicability to the problem of gate road stress reduction in deep retreat longwall coal mines. Candidate backfill materials include pulverized coal combustion fly ash, flue gas desulfurization, and fluidized bed combustion by-products from coal-fired electric power generation plants. Properties of both backfill and its component materials are presented, with particular emphasis on the unconfined compressive strength and elastic modulus of backfill mixtures. Hydraulic mix designs discussed in this report include high-water content slurry and low-water content paste fills. Three gate road stress-transfer-modification concepts are proposed to reduce abutment stresses in gate road systems. The first concept, packwalling, involves packwall construction behind the headgate shield inby the face and adjacent to the headgate pillars. The second concept, gob-filling, involves infilling a strip of gob inset from and parallel to the headgate using paste injection methods patterned after a technology recently developed in Europe. In the third concept, entry-filling, slurry fill methods are used to fill abandoned gate roads and crosscut entries inby the face.

Jan 1, 1995

By N. A. White

Whereas the ultimate world supply of energy minerals-defined as fossil fuels and fissile materials - is controlled by geological factors, the actual supply at any particular time is controlled by economic feasibility, technological innovations and /or political decisions. This paper identifies and discusses the principal uncertainties surrounding the international availability of energy minerals from now until the end of the century. A brief comparison is also made between energy and non-energy minerals. Genuine shortage s of energy minerals are now of a very long-term nature, whereas artificial ones may occur at any time and have a serious effect on the world economy due to the dependence of most OECD countries on imports of energy mineral . This paper argues that events over the last decade, such as the demand for a New International Economic Order, the OPEC increase in crude oil prices and the growing international lobby on environmental issues especially relating to nuclear safety - will progressively lead to a major, long-lasting transformation of the energy scene world wide. This transformation will encompass demand, in terms of conservation and efficiency, the supply mix of the various energy minerals , the supply system and the structure of the different energy industries . It is already affecting the role of governments and reaching into the question of national sovereignty both of developed countries, such as the U.K., Norway and Australia, and the developing countries, thereby making energy minerals a key area of international relations.

Jan 1, 1978

By H. S. Geismer

INTRODUCTION. THERE are three general methods available for obtaining commercial brown iron-ore : hand-screening; washing; and washing and concentrating. Hand-screening has produced a large tonnage of ore in the past, but is rapidly falling into disuse, except as a preliminary step, largely because modern furnace-practice requires all foreign material to be separated from ores before they are delivered to the furnace, and hand-screened ores can rarely be made to fulfill that requirement. Another argument against hand-screening is, that the waste-pile often contains as much ore as the screen recovers. The operation known as hand-screening consists of throwing the ore-bearing material against a stationary inclined screen of 0.5- to 0.75-in. mesh, similar in construction to the screens employed in sand-pits. The recently-prospected brown-ore deposits of Cuba seem to offer possibilities for hand-screening not possessed by the average American deposit, since these ores are not associated with worthless clays. Washing, and washing and concentrating, may be discussed together, since concentrating is never practical on brown iron-ore, except to treat ores that have already been washed. (Strictly speaking, washing might be classed as concentrating, but it is never so designated by brown-ore men.) The various steps of removing ore-bearing material and converting it into ore suitable for blast-furnace use, may be grouped under five heads: loading for transportation ; transporting ; feeding into the washer; washing; and concentrating. These five subjects will be considered in consecutive order. Each of these successive steps may be accomplished in a number of different ways, the choice depending entirely upon the character of the ore-bearing material to be treated.

Aug 1, 1911

By Hwasoo Park

Keywords: FC mold, Argon, Magnetic, Solidification Fluid flow plays a significant role for steel surface quality in continuous casting. Although water models are able to model fluid flow, the flow pattern is not of practical interest since the moving solidifying shell cannot be accounted. Computer modeling has become a popular and dependable tool to analyze the complex phenomena occurring in continuous casting. In this numerical simulation we coupled momentum and energy equations considering the solidification of steel along with turbulence ?-e model. The vertical bending mold is equipped with bifurcated nozzle with 15 degrees of port angle. FC mold is supplied with DC induced magnetic fields. Influence of argon and magnetic fields on molten steel flow and heat transfer is investigated by solving momentum equations adding source terms due to multiphase ? magneto hydrodynamics. The results show that magnetic fields reduce the jet velocity from port by lower magnetic core induced field but the influence on meniscus velocity is complex to describe. Magnetic fields increase surface temperature and homogenize its distribution on surface and inside a mold.

Jan 1, 2005

By Pedro Hugo Tumialán

El presente texto señala el proceso de mineralización del yacimiento metálico de Algamarca en Cajamarca a través de la descripción de la singularidad de sus características geológicas. De acuerdo a ello, se corta una inclinal de cuarcita de la formación Chimú del Cretáceo inferior, cuyo eje tiene un rumbo NW concordante al eje del anticlinal. Asimismo, el intrusivo Caupur es el causante de la mineralización de las vetas de Algamarca, las cuales resultaron por fuerza de compresión perpendicular al eje del anticlinal, formando algunas vetas dextrales y sinestrales, así como vetas de tensión perpendiculares al eje anticlinal. En este sentido, las vetas son angostas (O.la 0.3 m)peroricas en plata y su distribución se da en forma de arco de cada veta.

Nov 8, 1982

By T. Hollenberg, N. Nolten

The mining industry is one of the major energy consumers in Namibia. Energy costs increase the operating costs of Namibian mines, in particular, the processing plants, and result in an overall increase of production costs. A substantial part of the energy used is directly imported from South Africa. The cost of energy has been increasing rapidly in the past few years and will most likely continue to do so in the future. In 2015, the average wholesale price for energy from national power utility NamPower was US$87/MWh after rising more than 12 percent annually in the two previous years. At peak times, which are early in the morning and late in the evening, imported-energy prices are extremely high and have to be factored into the electricity tariffs. This problem is expected to intensify due to a projected 4 percent annual increase in energy demand. A major target of the Namibian mines, therefore, is to consider possible ways to address energy-saving challenges and to investigate possibilities for the mines to generate electricity internally during peak times. This is in alignment with the mines’ strategic plans and objectives to reduce total energy consumption and costs from both national and foreign electricity suppliers. In this paper, we explore addressing some of the key energy consumption and optimization challenges through process energy reuse and solar energy production to decrease demand for imported energy through a case study carried out in cooperation with Skorpion Zinc Mine and Refinery.

Jan 1, 2018

By K Blay, C McCamley, P Petrucci

The Newmont Boddington Gold (NBG) processing plant was designed for 35Mt/y with ball mills expected to deliver a combined new mill feed rate of 4837 tonnes/hr. Since beginning commercial production in late 2009, the plant has steadily increased throughput to meet design capacity in 2014 and reached 37 Mt/y in 2015. Through improved efficiencies, changes to the milling circuit have taken place since commissioning to take the plant beyond its design to an actual throughput of 39.0 Mt in 2017 and a budgeted throughput of 39.4 Mt/y this year.The NBG milling circuit has four parallel ball mills, each consisting of a 7.9 x 13.4 m ball mill with twin 7.5 MW fixed speed motors in closed circuit with twelve 650 mm cyclones. Each mill is fed by two wet screens with the undersize gravitating to a mill discharge hopper where it is combined with the ball mill discharge and pumped to hydrocyclones for classification. The cyclone underflow is re-ground to a target P80 of 150 µm.This paper will focus on process improvements made to the NBG milling circuit which include cyclone reconfiguration, fine screen panel redesign, implementation of an expert control system, mill power draw increase and grinding media changes to take NBG beyond its design throughput.CITATION:McCamley, C, Petrucci, P and Blay, K, 2018. Going beyond design at Newmont Boddington Gold, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 497–508 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By B Belle, M Biffi

Cooling of coal mines in the Bowen Basin, characterised by steep geothermal gradient, is presently achieved mostly through rental surface bulk air cooling in summer months. This paper argues that future mines will be required to focus their cooling resources more intensively to manage a challenging thermal environment where virgin coal temperatures of over 50¦C at a depth of 500 m are expected. Currently, mine cooling systems are employed to maintain the wet bulb temperatures (WBT) to below 27¦C at which point the risks of heat stroke or other heat-related issues are manageable. The capacities of these systems are in the range of 6 MWR to 10 MWR. The relationship between high working temperature environments and injury frequency rates is well established. Therefore, provision of appropriate cooling strategies and understanding their optimum performance and suitability are important to Australian coal mines of the future. This paper evaluates the underground temperature profiles of deep, gassy coal mines with propensity for spontaneous combustion and proposes the long-term cooling pathways to effectively manage thermal hazards. Thermodynamic modelling is performed on a longwall face and includes air leakage effects from goaf streams at various locations along the longwall face. The strategy summarises the application of underground bulk air cooling, chilled water sprays on the shearer and the resulting temperature profiles. Considering the new mining projects planned for the Bowen Basin region, a review of implementable cooling strategies such as mid-gate mobile bulk air coolers (BACs), spot coolers, underground bulk air cooling and the use of chilled water to enhance the positional efficiency of cooling plants, are discussed in this paper. Finally, the comparison of ærentalÆ versus æownershipÆ of cooling plants is analysed as part of long-term cooling strategies.CITATION:Belle, B and Biffi, M, 2013. Cooling pathways for deep Australian longwall coal mines of the future, in Proceedings The Australian Mine Ventilation Conference , pp 223-236 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

By Theodore M. Katz, W. Stephen Brightwell, David E. LeGrande, Joseph J. Hurrell, Jane A. Lipscomb, Nancy Lessin, Lawrence R. Murphy, Michael J. Colligan, Steven L. Sauter, Richard A. Lippin

Revolutionary changes in the organization of work have far outpaced our knowledge about the implications of these changes for the quality of working life and for safety and health on the job. This gap in knowledge is one of the 21 priority areas for research under the National Occupational Research Agenda (NORA)—a framework crafted by the National Institute for Occupational Safety and Health (NIOSH) and its partners to guide research into the next decade. This report was developed under NORA as the first attempt to develop a comprehensive research agenda for investigating and reducing occupational safety and health risks associated with the changing organization of work. Research and development needs identified in the agenda include (1) improved surveillance mechanisms to better track how the organization of work is changing, (2) accelerated research on safety and health implications of the changing organization of work, (3) increased research focus on organizational interventions to protect safety and health, and (4) steps to formalize and nurture organization of work as a distinctive field in occupational safety and health.

Jan 4, 2002

By Bell I. F

In 1985, ZC Mines (now Pasminco South) had been unprofitable for some years due to a combination of high operating costs, low metal prices, low head grade and an aging and inadequate mining infrastructure. However, the resource of metal in the ground was still of world class, even after some 80 years of mining. A major study, which was to be of two years duration, was therefore commenced to establish a practical and profitable long term mining strategy and to cost the infrastructure options needed for its support and thus form the justification for a capital expenditure program to take the mine profitably into the 21st century and its second century of operation. This paper discusses the rationale behind the methodology adopted and the nature of the results achieved in one aspect of the study - the determination of the mineable resource and the relationship between the head grade/quantity of the economically mineable resource and the variables of cut-off grade, cost structure, annual production rate and metal prices/exchange rates. The basis of the study was the designing of some 5000 scopes to mine out the entire resource for a range of cut- off grades and the assembly of the detailed physical data thus obtained in a stope-by-stope data base for financial and other analysis. Those scopes which were shown to be economically mineable were then scheduled for two optimum annual production/cut-off grade/metal price combinations to provide life-of-mine cost and value of production cash flows.

Jan 1, 1992

By Shailendra Chawla, Ashok Jaiswal, B. K. Shrivastva

The study aims to evaluate the pillar behavior during the depillaring operation by continuous miner (CM) technology. A panel with five headings developed as per the coal mine regulation of Indian coal mines [2] has been selected for the study. The depillaring operation has been carried out using CM technology after widening and heightening the original entries. An extensive field investigation has been carried out throughout the depillaring operation to access the mining conditions. Depillaring operation has been performed smoothly up to the middle of the panel (fourth row out of eight rows of four pillars each). Advanced blinking of the auto warning tell-tale (AWTT ) has also been observed on some of the instruments during the splitting of pillar no. 18. The panel shows extremely difficult mining conditions at this stage. The case has been numerically simulated using three-dimensional numerical techniques. The simulation result has indicated the high stress and yield condition on the working and the barrier pillar (surrounding goaf from both sides) after the extraction of pillar no. 18. The analysis has also indicated the marginal stability of the 2nd barrier pillar (namely “pillar B”). The failure of the barrier pillar could be the responsible for global instability of the panel as observed in the field. Understanding the importance of the barrier pillars, panel design has been modified by incorporating an additional row of barrier pillars. The stability of the modified panel has been evaluated. Both working and barrier pillars have been observed stable in the modified panel. This could be an alternative layout considering safety at the working face.

May 8, 2022

By V. Vern Hutchison

This selected list contains 829 entries with citations to Bureau of Mines publications related to petroleum and natural gas, which were released during the 1961-1970 period. Some entries are multiple in nature, resulting in a total of 881 citations.

Jan 1, 1972

By Charles L. Harness, A. T. Coons

Sodium carbonate, Na2CO3, more commonly known as soda ash, is the most important of the alkalies. Sulfuric acid is the only heavy chemical, Soda ash enters the market either as the natural product or as a manufactured derivative of common salt. Notwithstanding their common occurrence in closed basins of the Western States, natural sodas are produced at present by only four firms, all in the same California area, and satisfy only 4 percent of domestic demand for soda ash; soda ash made from salt supplies 96 percent of the requirements. The impossibility in wartime of routing all westbound American shipping through the Panama Cami.l has curtailed Pacific Coast receipts of soda ash and-increased the importance of local resources of natural carbonates. One of the most promising of ·these is the recently discovered trona (sodium sesquicarbonate)· deposit 2o·mnes· west of Green River, Wyo. Reserves are likely to run into hundreds ·of million·s of tons, and the deposit probably could be worked by the room-and~pillar· system of mining, like common salt or coal. • • Raw materials ·ne·cessary for manufacturing synthetic soda ash occur closely associated in m·afiy parts· bf the United 8tates. Almost unlimited resources of salt in brines and in rock-salt depbsits are located near limestone quarries in many areas. The· limesto'ne furnishes the carbon dioxide for the manufacture of soda ash arid the lime f o'r the recovery of ammonia. used in one step of the process. Expansion of the industry to meet wartime needs depends chiefly on availability of trained labor, materials, and equipment necessary for the erection of additional units.

Jun 1, 1942

By Leena Korkiala-Tanttu, Noora Lindroos, Juha Forsman

"Construction works at the Helsinki city sea shoreline requires dredging and handling of contaminated sediments. Most of these soft dredged sediments are regarded as too poor quality material for earth construction purposes. Mass stabilization technology has been applied to improve the technical and environmental properties of the dredged sediment in order to utilize the material in construction. The treatment site presented in this article is placed in the West Harbor where the dredged sediments are disposed in basins, mixed with binders by mass stabilization and transported to utilization sites. The volume of these basins is about 90 000 m3. So far these basins have been used three times during the years 2011-2014. The most applied binder has been cement. Its high price and carbon footprint have encouraged use alternative binders. Other used binder materials include fly ash and end product of desulphurization from coal combustion, and fly ash from combustion of Estonian oil shale. The technical and environmental properties of stabilized sediments have been studies in the laboratory and in situ thoroughly. Some properties of the stabilized sediments which have been studied are: compression strength, modulus, hydraulic conductivity, leaching of contaminants, etc. The leaching test results show that heavy metal leaching is very low with all binder materials tested.1. INTRODUCTIONContaminated marine sedimentsMarine sediments in the coastal areas are often contaminated as a consequence of industrial and port activities, as well as the influence of cities located there. Construction activities and reclamation of shore line require dredging and handling of contaminated sediments since the level of contamination inhibit dumping of dredged sediments into the sea. Based on their technical properties, most of these dredged soft and watery sediments (clay, gyttja, etc.) are regarded as too poor quality material for earth construction purposes. Economic, sustainable and environmentally safe management of contaminated, dredged sediments is a key issue in many construction sites.In the City of Helsinki, mass stabilization technology has been applied to improve the technical properties of the dredged sediments in order to utilize the material in construction. Owing to stabilization / deep mixing / solidification, also the contamination is encapsulated in a monolithic solid of a high structural integrity. Thus, contaminants migration is restricted by the decreased surface area exposed to leaching.The treatment site presented in this article is placed in the West Harbor (a place of Helsinki called Jätkäsaari) where dredged sediments are disposed into stabilization basins, mixed with binders by mass stabilization and then transported to final utilization sites. The location and principle of these basins is presented in Figures 1-4. The overall volume of these four stabilization basins is about 90 000 m3."

Jan 1, 2015

By C. Matthews, A. Vo

"Australia is one of the world’s leading exporters of bulk commodities and the extensive use of sampling equipment is key to the successful management of each mining operation. At the process plant, without a full understanding of the feed, product and tails, it is impossible to fully optimise the performance of the plant, such that the metallurgical balance is often open to error. At the port, a statistically correct, bias free and compliant sampling system is crucial to ensuring exported minerals are reflective of their true value and to avoid penalties. Over the last decade, as a result of the iron ore boom, there has been high demand for reliable, representative and standard compliant solids sample systems in Australia. This paper reviews several solids sampling applications at Australian mine sites, the challenges and experience gained and how the implementation of reliable representative sampling systems has provided better understanding of plant process performance, improved plant control and overall benefits to the operations.INTRODUCTION Mining is the primary contributor to the Australian economy with Australia ranking in the top 4 in economic resources for 21 primary industrial minerals in 2016 (Britt, et al., 2017). Australia is one of the world leaders in the export of the majority of its commodities including gold, copper and iron ore (Britt, et al., 2017). Therefore, a suitable and standard compliant sampling system is essential for evaluating plant performance and content verification. At the mine and at the port, the larger iron ore miners in Australia have developed stockpile models to predict the grade of their ore down to individual blocks of the stockpile. This allows the miner to create the right blend of material for sale to their customers and ensures they are not underselling their product or at risk of penalties for impurities or low grade. As an example, the average difference between the benchmark 62% Fe and low grade 58% Fe fines at the time of this report averaged US $30/tonne according to the Metal Bulletin Iron Ore Index. At a shipload of 180kt this would be a variation of US $5.4M. Whilst this is an extreme example, it highlights the economic importance of producing the correct grade product and a recognised representative sample of said product."

Jan 1, 2019

By H. B. FERNALD

THE interesting and carefully developed formula which Professor Bucky presents for answering the question of whether proposed new equipment will give a net return on investment equal to or greater than that on present equipment starts with an assumption that the management may make this relative return a determining factor in its decision whether or not the new equipment should be provided. I do not question that in some cases the management may take this position, but I would point out the error involved in so doing. The proper test is not a comparison of the return on new as compared with the return on old investment, but is rather a comparison of the return on a particular new investment as compared with the return which would be obtainable from some other new investment which now might be made. Then I would point out that I believe Professor Bucky is in error in using as a factor in his computations the item of unamortized cost of old investment. The financial advantage to be derived from a new investment does not depend on the extent to which we may in the past have written off the cost of old equipment, nor does it even depend upon what was the original cost of that old equipment. Even the salvage or resale value of the old equipment will only enter into the picture to the extent that the present salvage or resale value differs from the ultimate salvage or resale value otherwise to be obtained, after due allowance for the interest factor.

Jan 1, 1930

By Frank E. Cash, Max S. Petersen

The use of safe equipment, safeguards, and safe practices in the mining and allied industries should reduce injuries and improve accident experience. The object of this report is to give to the mining industry, especially metal mining, a graphic pictorial description of some of the safeguards, equipment, and practices used and followed in the iron-ore mines of the Lake Superior district. Some of the subject material has been in use or has been established for many years, and some is relatively new. Some of the equipment was purchased commercially, and some was designed by the company employees and constructed in the mine shops. The photographs were taken by the personnel of the Health and Safety Division of the United States Bureau of Mines, primarily for use in the Metal-Mine Accident-Prevention Course of the Bureau of Mines. In general, they are arranged under the following headings or subjects: 1. Accident statistics. 2. Support of ground. 3. Hoisting and haulage. 4. Explosives. 5. Fires, gases, and ventilation.

Oct 1, 1948