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By Christopher Laughton, Michael P. Bruen

At Fermilab, a 4000-ft long underground complex has recently been constructed for a high-energy physics experiment. The complex is sited up to 350 ft, below grade principally in bedrock. The rock excavations were mined by TBM and drill and blast methods and supported by a combination of rock bolts, dowels and shotcrete. Water control was achieved using a combination of pre- and post-excavation grouting, drainage systems, drip shielding and air desiccation measures.

Jan 1, 2003

By Wilbur J. Morin

Construction of Flaming Gorge Dam in northeastern Utah necessitated the construction of a new state highway, Utah-260, to provide access to the dam and the town of Dutch John. A 550-foot arch structure was designed to span Cart Creek, about one mile southwest of the dam. The rock exposed at the site is highly fractured quartzitic sandstone with interbedded shale of the Precambrian Uinta Mountain Group. Eight exploratory holes were drilled, four in each abutment area, to determine rock types, the extent of fracturing at depth and rock strength. Drill cores in the west abutment revealed blocks of quartzitic sandstone loosened by the weathering and partial removal of underlying shale beds. The rock in the east abutment area was found to be highly fractured to depths of 70 feet and as far east as 50 feet from the footing locations. Selected core sections were tested for unconfined compressive strength but the values were not considered-representative of the in-situ fractured rock. To prevent movement along or, perpendicular to open fractures, four drilled-in columns were provided at the base of each footing. These extended 50, feet beyond the base of the footing, along the bearing and inclination of the thrust reaction.

Jan 1, 1963

By Jay F. Colinet, John A. Organiscak

In This Chapter [Which dust source to address first How much air and water are needed Keeping dust out of the walkway Moving workers upwind Dealing with the stage loader-crusher Gob and wing curtains to aid airflow The shearer-clearer system Modified support movement practices and Dust control for future longwalls ] Controlling longwall dust is not easy. Longwall production levels are high, and there are several different sources of dust to contend with. If dust levels are high, the initial effort should be devoted to finding which source is the cause. Then, efforts to reduce dust can be concentrated where they will have the most impact. To control dust at longwalls, a large amount of ventilation air and spray water must be used. The water must be sprayed correctly so as not to blow dust into the walkway. Techniques to change local airflow patterns can be helpful. The shearer-clearer, as well as gob and wing curtains, are examples of such techniques. DECIDING WHICH DUST SOURCE TO ADDRESS FIRST [If a longwall is out of compliance with dust standards, knowing where the extra dust is coming from helps to get back in compliance quickly.]

Jan 6, 2003

By H. E. Nold

THIS paper is an effort to explain in a simple manner the fundamental principles involved in examining a clay deposit for both quantity and quality and in operating a clay mine, either open-pit or underground, so that the best quality of finished material can be made from the raw material available. The writer is aware that what is recommended in this paper is everyday practice in many refractories plants and in some other heavy-clay products plants, but observations made while visiting practically every clay mine in Ohio have convinced him that the practices herein discussed are not as widely used as their importance warrants. It is true that the problem of mining for quality is more acute in refractories plants than in most heavy-clay products plants, yet some of the latter are finding it profitable to pay more than ordinary attention to the selection and blending of their raw materials. It is hoped that this short paper may prove helpful to some who are now finding it difficult to produce a uniform product of as high quality as their clay deposit seems to warrant. The coordination of the work of the clay mine or pit with the manufacturing plant, to the end that the best product possible be made from the raw material available, presupposes a rather intimate knowledge of the clay deposit. The knowledge must include not only information of the amount of clay-available but also rather detailed information about both vertical and horizontal variations in quality of the clay. This information should cover three things: quality, quantity, and location.

Jan 1, 1929

By Hugo E. Camargo

Noise Induced Hearing Loss (NIHL) is the most common occupational disease in the U.S. with devastating consequences particularly in the mining industry. A study conducted by the National Institute for Occupational Safety and Health (NIOSH) revealed that 90% of coal miners have hearing impairment by age 50, compared to only 10% of those not exposed to occupational noise. According to the Mine Safety and Health Administration (MSHA), Continuous Mining Machine (CM) operators account for 30% of workers exposed to noise doses exceeding the Permissible Exposure Level (PEL). This number becomes more dramatic considering that 49% of the total national underground coal production is extracted using these machines. In this context, NIOSH is conducting research to identify and control dominant noise sources in CMs. Previous noise source identification was performed using a Brüel &Kjær (B&K) 1.92-m diameter, 42-microphone phased array. These measurements revealed that the impacts from the conveyor chain onto the tail roller, and the impacts from the conveyor chain onto the upper deck are the dominant noise sources at the tail-section of the CM. The objectives of the work presented in this paper were: 1) To rank the noise radiated by the different sections of the conveyor, and 2) to determine the effect of a urethane-coated tail roller on the noise radiated by the tail-section. This test was conducted using an Acoustical and Vibrations Engineering Consultants (AVEC) 3.5-m diameter, 121-microphone phased array. The results from this new test show that a urethane-coated tail roller yields reductions in the tail-section of 2 to 8 dB in Sound Pressure Level in the frequency range of 1 kHz to 5 kHz. However, integration of the acoustic maps shows that the front-section and mid-section of the conveyor also contain dominant noise sources. Therefore, a urethane-coated tail roller in combination with a chain with urethane-coated flights that reduces the noise sources in the front and mid sections of the conveyor is required toyield a significant noise reduction on the CM operator?s overall exposure. These results show the applicability of phased array technology for low frequency noise source identification.

Jan 1, 2008

By J. L. Stauffer, L. J. Gaydos, L. M. Demers, D. C. Kuhn

"Eicosanoids and cytokines produced by alveolar macrophages (AM) are key mediators of pulmonary inflammation and fibrosis. In order to determine if eicosanoid production and cytokine production are altered in AM obtained from coal miners, we compared production of prostaglandin E2 (PCE2), thromboxane A2 (TXA2), leukotriene B4 (LTB4), interleukin-1 beta (IL-1B ), and tumor necrosis factor alpha (TNfa.) by cultured AM from normal human subjects and coal miners. The recovery of AM from miners' lungs by bronchoalveolar lavage was significantly greater than that from control subjects. Mean eicosanoid and cytokine production by AM from active miners was also increased compared to AM from control subjects, but this increase was not statistically significant. AM from control subjects produced significantly more TXA2 and TNFa. when exposed to lipopolysaccharide than did AM from miners. The cyclooxygenase inhibitor suprofen reduced PGE1 and TXA1 production and TNF0t. release but had no effect on LTB4 production or IL-1B release by miners' AM. The lipoxygenase inhibitor nordihydroguaiaretic acid attenuated TNFa release, as well as that of LTB4, but had no effect on IL-1B release. Inhibition of thromboxane synthase by UK 38,485 also reduced TNFa release by active miners ' AM but had no effect on PGE1, LTB, production, or IL-1 f3 release. The results of these studies suggest that occupational inhalation of coal dust may increase total lung eicosanoid and cytokine levels and reduce the reactivity of AM to bacterial endotoxin. Furthermore, coal dust-induced changes in both eicosanoid and cytokine release may be subject to pharmacological modulation.The alveolar macrophage (AM) is a primary defensive cell in the lung and is one of the first cell types to encounter inhaled mineral dust. The response of the AM to invading foreign material is designed to enhance the defensive capacity of the lung. However, in the case of occupational inhalation of mineral dust particles, this response may be inappropriate, resulting not in the defense of the lung but in chronic inflammation and fibrosis (Rom et al., 1987; Takemura et al., 1989). The reaction of the AM to chronic mineral dust exposure may involve the exaggerated release of paracrine mediators of lung function, including eicosanoids (oxygenated derivatives of arachidonic acid) and peptides, including cytokines and growth factors (Sibille & Reynolds, 1990). Eicosanoids are involved in bronchial and vascular smooth muscle reactivity, vascular permeability, fibroblast growth, and the recruitment of additional immune cells to the alveolar space (Barnard et al., 1992; Elias et al., 1985; Scott et al., 1982). AM-derived cytokines such as interleukin-1 beta (IL-1 B) and tumor necrosis factor alpha (TN Fa) have a variety of biological activities including the regulation of fibroblast growth and proliferation (Becker et al., 1989; Libby et al., 1989; Schmidt et al., 1984). Interestingly, in vitro studies with macrophages suggest that the production of cytokines may be linked to eicosanoid production, in particular that prostaglandin E2 (PGE2) may down-regulate IL-1 f3 and TN Foe production by the AM (Bonta et al., 1989; Kunkel et al., 1986; Monick et al., 1987)."

Dec 1, 1996

By P. N. Anyalebechi

"The as-cast microstructure of two commercial-size ingots of aluminum alloy 3004 produced by the electromagnetic casting process was quantitatively characterized. This involved the quantitative determination of through-thickness and across-width variations in dendrite cell size, grain size, macrosegregation of alloying elements, interparticle spacing, and the types, volume fractions, and sizes of the constituent or second phase particles. More than ninety-five percent of the constituent phases in the ingots consisted of the A16(Mn,Fe) phase; the desirable a-Al 12(Fe,Mn)3Si phase was not detected in any of the ingots by Guinier X-ray diffraction analyses or electron probe X-ray microanalyses. A significant microstructural heterogeneity through the thickness and across the width of both ingots was observed. For example, macrosegregation, and the sizes of the constituent phase particles, dendrite cells, and grains increased concomitantly from edge to mid-width and from surface to center of the ingots. There was a -20% depletion (negative macrosegregation) of Mg and a +54-87% enrichment (positive macrosegregation) of Ti in the center of the ingots. With the exception of grain size, there was no significant microstructural difference between the two ingots examined. The causes and practical implications of the observed microstructural heterogeneity in the ingots are discussed.IntroductionThe first step in the fabrication of majority of wrought products of aluminum and its alloys is the casting of large ingots or billets of simple shapes (round or rectangular). The sizes of the ingots vary from 10 mm to 450 mm diameter or 25 mm to 780 mm thick. The quality of the finished products is established at the ingot casting stage. This is because the microstructural characteristics, such as secondary dendrite cell size or arm spacing, amount of alloying elements retained in solid solution, macrosegregation, and the characteristics of second phases, produced during casting cannot be reversed by subsequent processing. Up until twenty-five years ago, the effect of as-cast microstructure of large ingots on the structure and behavior of thin sheets (0.34 mm thick) during drawing and ironing processes was incorrectly assumed to be minimal or nonexistent. This was based on the erroneous notion that the thermal treatments and large reduction (>99.94%) and strain that the ingot undergoes during production of the sheets completely destroys the original ingot structure and its inherent heterogeneity. However, the effects of ingot structure can, a priori, be deduced from the observed effects of constituent phase particle size, type and volume fraction on recrystallization, development of texture during annealing and deformation, and earing. In fact, careful examination of the behavior of products produced from different size ingots or castings have shown that the original microstructure of the ingot has a direct impact on the properties and performance of the end products."

Jan 1, 2011

By N. Aslin, R. Clark, G. Heferen

The methods of harvesting copper from stainless steel mother plates has been investigated from fundamental and operational experience perspectives. At least five different harvesting techniques have been identified that have different effects on product quality, current efficiency, current distribution, growth morphology and ease of stripping. Each method is examined from fundamental principles to understand what occurs during the harvesting process and why the particular effects are manifested. Experience from plants operating the harvesting method is provided to show that the fundamental understanding is relevant. Best practice harvesting method and harvesting management are described.

Jan 1, 2014

By P. Christmann

"In June or July 2005, the European Commission will present its Thematic Strategy on the Sustainable Use of Natural Resources proposal to the Council and European Parliament, one of the seven Thematic Strategies to be developed and implemented under the 6th European Environment Action Programme in support of the European Union’s Sustainable Development Strategy defined by the European Union’s Head of State at the Göteborg European Council, in June 2001. The time scale for this Thematic Strategy is 25 years (2005-2030). This paper discusses some of the key issues related to the EU minerals and metals industry that needs to be addressed by the Strategy. These are: - the need for access to mineral reserves in the EU and abroad; - the need to strenghten the capacity of developing countries to sustainably promote and regulate the use of their mineral potential; - the need for an EU mineral resources intelligence capacity. There are additional important needs, which are not discussed in this paper, such as: - the need to foster further innovation in mining, ore beneficiation and metallurgical technologies; - the need to integrate and simplify the exisitng complex regulatory framework applicable to the EU mining industry and to effectively implement existing legislation."

Jan 1, 2005

After the Loma Prieta Earthquake, which caused major damage to viaducts in the Bay Area, the California Department of Transportation set up a test programme for foundation piles. Funderingstechnieken Verstraeten B.V., beter known as Fundex, was approached, since one of the piling systems of Fundex, named Tubex, is extremely suitable in areas sensitive to earthquakes and we were very much interested to prove the capabilities of this piling system. Equipment For the installation of Tubex and Tubex grout-injection piles special piling equipment is required. Since our company is not only a contractor, but also a designer and manufacturer of piling equipment, all special equipment for our range of foundation techniques is designed and built by our own piling equipment department. For the installation of both Tubex piles and Tubex grout-injection piles for the Caltrans test programme, the following pieces of equipment were selected: a) Fundex F12 piling rig b) Drill table c) Hydraulic powerpack d) Grout mixing unit and high pressure pump

Jan 1, 1993

By M. Bélanger, H. -L. Jacob

"The province of Quebec has a strong tradition in industrial minerals. Ten commodities are produced and the annual total shipments have exceeded $600 million in recent years. Quebec is a world renowned producer of chrysotile, titanium slag, graphite, and ilmenite. Quebec is an important North American producer of mica, talc, and peat moss. This paper reviews the main minerals and commodities that have been the object of exploration or development in recent years, namely graphite, wollastonite, dolomite, and silica. Some of the leading projects concerning magnesium minerals and apatite-ilmenite are described. IntroductionQuebec has a strong tradition in industrial minerals. It goes back to the second half of the 19th century when the first graphite and apatite mines in the Gatineau area and asbestos mines in the Eastern Townships were opened. Since then, more than 25 commodities have been produced in Quebec, making industrial minerals an integral part of the Quebec mineral industry. Today, industrial minerals and building materials count for one third of the total mineral production in Quebec.Present industrial mineral production includes 10 commodities (Table 1). In the last five years, the value of industrial mineral shipments has varied between 500 and 700 millions dollars annually, which represents 20% to 25% of Quebec’s total mineral production. For many years, Quebec has been a major producer of chrysotile and titanium slag, the only producer in eastern North America of mica, graphite and ilmenite, and a leading Canadian producer of talc and peat moss. Quebec also produces, mainly for domestic markets, dolomite, limestone, salt and silica.Quebec’s industrial mineral sector has been quite active in the recent years. Exploration by government geologists and companies has led to the outlining of new deposits, some of which are now in production; others are currently being evaluated. Technical and economic studies are also underway to determine the feasibility of various development projects."

Jan 1, 1999

By K. K. Kelley

This report contains heat-content values for hexagonal crystalline germanium dioxide between 298.15° and 1,350° K., and for germanium dioxide glass between 298.15° and 1,800° K. experimentally determined by the Federal Bureau of Mines. No similar data for these substances are to be found in the literature. The heat-content and corresponding entropy-increment data are presented both in tabular form and by equations. Free energy of formation values are estimated for germanium dioxide glass at 298.15° and 1,800° K.

Jan 1, 1961

Most coal mines in Chongqing Area are highly gassy mines and liable to outburst of coal cnd methane. In order to harness mine environment and raise the Prodction capacity, methane predrainage is generally taken as a main preventive measure against outburst by all mines. In the recent ten years, the drainage volume per year has increased from 38.25 million m3 to mote than 100 million m3 with a volume over 12 m3 per tome of coal. In some mines, the draining rate is approaching to 50 percent, the rate in mining districts is up to 60 to 70 percent. The predrainage volume accounts for one fourth of total drainage volume. All these have effectively prevented the occurrence of coal and methane outbursts.This is the current situation of methane predrainage in coal mines in Chongqing area, the methods of predrainage to prevent outbursts and related parametres comprise:1. methods, technologies, supervision and effect of predrainage in different geological and mining conditions,2. the change of methane parametres pre-and post-drainage and the analysis of the effect of methane predrainage to prevent outbursts, and3. ways to improve the effect of methane predrainage.Thus the safety, reliability and production of Changqing Coal Mines will be enhanced.

Jan 1, 1991

ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Member, technical graduate, aged 36. Experienced copper metallurgist and mining geologist. Familiar also, through 15 years' broad practical experience, with mining, cyanidation, concentration (including oil flotation), metallurgical accounting, and mine and plant management. Best references. No. 237. Member, graduate engineer with 10 years' experience in malleable, gray -Iron, and steel, as chemist., metallographist, and metallurgist. Researches and investigations by laboratory methods and under works conditions. No objection to some routine. No. 243. Member, technical graduate, broad experience in coal, oil, and clay. Will go anywhere as mining geologist after Sept. 1, 1915. No. 244. Member, technical graduate, aged 30, married, with over 10 years' experience as chemist, engineer on construction, superintendent and general superintendent of bituminous coal and coke plants. SpeaksSpanish. References. No. 245. Member, open for engagement as mine safety inspector or as superintendent of bituminous coal mine. No. 246. Member, graduate mining engineer, with five years' experience in coal mining as mining engineer, construction engineer, pit boss, and superintendent, open for engagement. Best references. No. 247.

Jan 9, 1915

By Frederick J. Browne

Water, water everywhere, but not a drop (fit) to drink! Trite, but how often only too true? What is there met with in mining which, under various circumstances, may be said to be the most sought-for and highly-prized and also the most objectionable and most feared? Water! What visions that combination of five letters brings to all thoughtful minds? Up to near the end of the eighteenth century water was thought lo be an element but was then discovered to be the result of the combustion of two volumes of hydrogen with one volume of oxygen, and water so produced is chemically pure. Pure water is a clear and colourless liquid when seen under ordinary conditions, but appears bluish when seen through a long tube, and this same bluish tint may be observed in many lakes, especially those of glacial origin. A story often told describes a prospector in the desert who, failing to find water to replenish his canteen, suffers torture and death under fearful circumstances. Then again we may recall the flooding of mines, where water poured in so quickly that there was no opportunity of saving the unfortunate workmen. Instances might be multiplied without number showing that either the lack or excess of this essential fluid has taken heavy toll of human life. In all branches of mining and associated industries water must be dealt with to a larger extent, from an economic point of view, than any other substance, and very often the purity of the water is a matter of considerable importance.

Jan 1, 1925

By Fumihiko Sumiya, Shinya Tanaka, Yukio Kato, Kenji Tanaka, Tetsuya Sawada

When explosives are heated under an acidic environment due to metal sulfide and sulfuric acidity, their decomposition temperature falls remarkably and decomposition reaction occurs quickly, and then explosives have the risk of the deflagration to the detonation transition. Heat resistant commercial explosives which can be used under conditions of high temperature of 200ºC and an acidic environment were studied. We developed the explosive composition consisted of ammonium perchlorate (AP) as oxidizer, saturated hydrocarbon oil as fuel and binder, and calcium carbonate as decomposition inhibitor. The characteristics of this explosive composition show a heat resistance over 24 hours at 200ºC, and a detonation velocity over 2,500 m s-1. This explosive composition has a cap-sensitivity at temperature higher than 100ºC. Cost effective heat resistant commercial explosives were created by the optimization of the grain size of AP as a main component, the addition of saturated hydrocarbon oil and calcium carbonate, and the control of bulk density by the addition of micro-balloons.

Jan 1, 2003

By M. Irish, M. Jahraus

Accurate prediction of gold (or other metal) production from a heap leach operation is essential to the economic vitality of any such operation. However, this is also one of the most challenging issues facing managers of these facilities. Three approaches to modeling gold production from the Valley Leach Facility (VLF) at Anglogold’s Cripple Creek & Victor Gold Mining Company are presented. Evolution of these modeling methods has been necessary as ore heights and volumes have increased. In addition, the complex geometry of the VLF presents additional complications to production modeling, Comparison of actual and predicted gold production are presented

Jan 1, 2001

By Varadarajan Seshadri

A physical model based on similarity principles was constructed for simulating the RH degasser of CST (Companhia Siderurgica Tubarao, Vitoria, ES, Brazil) to evaluate the circulation rate of the metal which essentially defines the degree of exposure of the metal to vacuum in the chamber and thus of the refining rate. The circulation rate on the other hand will influence the decarburization rate and removal of dissolved gases like nitrogen and hence it is essential to optimise this parameter to get maximum refining efficiency with minimum refming times, thus improving the productivity of the secondary refining process. Mixing characteristics in the ladle is evaluated by pulse tracer addition using conductivity-meters located at the down leg as well as at several locations in the ladle. The influence of gas injection through nozzles in the upleg with simultaneous bottom injection of gas as well as nozzle blockage on the circulation rates were investigated. Also simulation experiments of kinetics of decarburization were carried out using C02 adsorption-desorption process in sodium hydroxide solution as circulating fluid and the effect of, bottom gas flow rate in this case was also evaluated. The results were carried over to prototype and to optimize the process.

Jan 1, 2003

By M. D. Carter

The availability of environmentally acceptable and reliable energy sources is an important issue for Federal, State, and local planners. A cooperative program by the U.S. Geological Survey, State geological surveys, and the U.S. Bureau of Mines has developed a national GIS-based systematic effort to collect, analyze, and depict data characterizing the relationship between restrictions to mining and the potential development of the Nation's coal resources. Land use/environmental and technologic/geologic restrictions are identified within selected 1:24,000-scale, 130-to 150-sq-km 7.5-min quadrangles and applied as overlays to maps of coal-bed thickness, depth, and mined-out areas. Tonnages of original, mined and lost-in-mining, remaining, restricted, and available resources are calculated. Resultant data files are transferred to the Bureau of Mines for recoverability and cost analysis.

Jan 1, 1995

By T R. Anderson, A R. Butler

Haymont (2012) notes that in parts of Australia significant areas of mining disturbance cannot be relinquished. In Queensland it has been estimated that by 2010, just 0.3 per cent 507 ha of mining disturbance had been rehabilitated to the regulator’s satisfaction (Short, 2015).One reason for this poor record is the presence of inappropriate, unachievable or unmeasurable rehabilitation targets (Glenn et al, 2014; Butler, Anderson and Sexton, 2015). In the authors’ experience in Queensland many mature operations have licence conditions that hinder the achievement of sustainable outcomes or prevent successful validation of rehabilitation success. This creates a lack of certainty for industry and a lack of confidence in the community that the sector can deliver good rehabilitation outcomes (Short, 2015).This extended abstract presents a framework approach that has been applied at two contrasting operations. Without the changes presented, the goal of progressive rehabilitation certification, reduction in financial assurance (FA) and a path to surrender at these sites would have been impossible. The framework can be adapted for use across different bioregions and commodities.CITATION:Butler, A R and Anderson, T R, 2016. Reassessing rehabilitation objectives and targets for mature mining operations in Queensland, in Proceedings Life-of-Mine 2016 Conference, pp 139–141 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016