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By Brian Danyliw

"Dust control is an increasingly important consideration for all mining operations from a health, safety, environmental and maintenance perspective. Modern mining operations incorporate a variety of mechanical dust control techniques into design however in many cases these engineered systems are unable to meet desired fugitive dust level targets. In these cases a variety of chemical dust suppression options are available to operators to assist in meeting their targets. This paper provides an overview of available chemistries, discussion of application techniques and equipment requirements and available performance monitoring technologies. This paper will also include a number of case histories discussing the treatment approach chosen, challenges encountered, chemical feed, storage and application equipment, monitoring techniques employed and results achieved.INTRODUCTIONDust FundamentalsFugitive dust by definition is an aerosol consisting of particulate matter suspended in a gaseous medium. Aerosols can include suspensions of particulate (solids) or sprays (liquids) or a mixture of both. Of particular concern from an occupational health and safety perspective are aerosols of particulate matter due to their involvement in classical occupations lung diseases such as silicosis, poisoning through chronic exposure to compounds such as lead and beryllium and expected involvement in more modern identified conditions such as cancer, asthma, and a host of other respiratory and non-respiratory conditions which may be caused or influenced through exposure to dust.According to the ""Glossary of Atmospheric Chemistry Terms"" (IUPAC, 1990), ""Dust: Small, dry, solid particles projected into the air by natural forces, such as wind, volcanic eruption, and by mechanical or man-made processes such as crushing, grinding, milling, drilling, demolition, shoveling, conveying, screening, bagging, and sweeping. Dust particles are usually in the size range from about 1 to 100 µm in diameter, and they settle slowly under the influence of gravity."" It should be noted that the behavior of particulates with respect to settling rate in air is a function of particle mass and shape and therefore the geometric size of the particle can be misleading. Occupational hygienists utilize the concept of particle aerodynamic diameter as a more representative reflection of particle size. Particle aerodynamic diameter, is defined as ""the diameter of a hypothetical sphere of density 1 g/cm3 having the same terminal settling velocity in calm air as the particle in question, regardless of its geometric size, shape and true density."" The expression of particle size as aerodynamic diameter allows for a more consistent understanding of particle behavior both from a settling perspective as well as from the perspective of how dust particles will behave in the respiratory tract. Figure 1 illustrates settling rates for particles of various aerodynamic diameters. The relationship between particle size and settling rate is important for understanding what size of particles must be addressed by dust control strategies as well as what particle sizes represent the most danger from an exposure and occupational health perspective."

Jan 1, 2015

By Jr .. Ebbley

The investigation of mine shafts and underground workings at Leadville, Colo., was started in May 1946 and recessed in November 3, 1946. Thirty-eight shafts and connecting accessible underground workings, comprising about a third of the accessible shafts in the district, were investigated. The Leadville district, a former important producer of lead and zinc, was considered by the Bureau of Mines to be capable of bolstering 'the waning domestic output of .these important metal. Accordingly, the investigation was initiated for the purpose of. .obtaining more definite data on sulfide and oxide reserves, evidence to justify completion of the Leadville drainage tunnel, representative large samples of the complex oxidized and mixed ores for testing to determine methods, beneficiation factual data to be supplied to property owners in order to stimulate production, and to determine the more favorable areas for development by the Bureau.

Jan 1, 1949

By Jan Krull

A high productive coke making process in connection with stringent emission control has clearly become a demand of plant operators and stakeholders. Further to this, availability, quality and coal costs are key concerns for the iron and steel industry in its efforts to optimize raw material cost. Today, the optimization of raw material cost in integrated steel works has further gained priority. Coking coal reflects up to 20% of the cost of steel. In top charged batteries coal preparation and blending is one of the concerns to lower coal cost by maximizing the percentage of non-coking coals in the blend. Stamp charging technology is technologically and economically an effective solution in the process of pre-carbonisation. Paul Wurth’s jumbo top charged oven as well as proven stamp charging technology have recently set new benchmarks in Europe, India and Brazil in terms of productivity, stability and emission control.

Aug 1, 2018

By Tad S. Golosinski, R. Larry Grayson

Online education is not new. During the last decade, it has reached the stage where many universities offer a variety of courses, degrees and programs without any associated residency requirements. The most successful of the online universities, University of Phoenix, offers hundreds of accredited programs for close to 100,000 students throughout the world (www.phoenix.edu). Online education is considered to be a valid equivalent to traditional, classroom-based education. It is best suited to the needs of mature students with full-time jobs and a desire to deepen their knowledge. While most of the e-business has experienced severe setbacks during the last two years, e-education shows no signs of slowing down. On the contrary, the number of students and institutions offering online education keeps growing. The value of e-education associated expenditures was expected to reach $300 billion in 2001 (Sanoff,2001), making it a serious and mature industry.

Jan 1, 2002

By S. Jennings

The Red Dog zinc-lead-silver deposit is located in the DeLong Mountains of the western Brooks Range in northwest Alaska. The region is located 145 km(90 miles) north of the village of Kotzebue (Fig. 1).Red Dog’s current resource base is 143 Mt (157 million st) averaging 16.1% zinc, 4.3% lead and 83g/t (2.4 oz/st) silver. It is contained in four structurally separate deposits— the Hilltop, Main Deposit, Aqqaluk and the newly discovered Paalaaq deposit. Recent exploration for the Aqqaluk and the Paalaaq deposits has contributed to Cominco American’s understanding of the detailed structural geology of the district and its role in the placement of individual ore bodies.

Jan 1, 1999

By Tim O’Neil

Nearly 4,800 mining professionals and exhibitors occupying 580 booths attended the 2000 SME Annual Meeting and Exhibit, Feb. 28-March 1, in Salt Lake City, UT. The technical program included80 sessions and four specialty symposia: bulk material handling, control 2000, minor elements 2000 and plant operaters. Meeting highlights included the keynote session. Executive shared their perspectives on pivotal issues and approaches to address the challenges of the new millennium. SME has begun planning for its 2001 Annual Meeting, Feb. 26-28, in Denver, CO. The meeting carries the theme “2001 — A Mining Odyssey.” A call for papers has been issued and exhibit space is 80% reserved. For information, visit SME’s website, www.sme-net.org. Or write Box 625002, Littleton, CO 80162-5002,ph 800 763 3132 or 303 973 9550, fax 303 979 3461, or email meetings@smenet.org.

Jan 1, 2000

By B. K. Gorain

"Mining of low grade deposits along with the necessity to design and operate process plants requiring high throughputs presents unique metallurgical environmental and sustainability challenges that need to be addressed to reduce project risks, improve project economics and to sustain the profitability of operations over the life-of-mine.Some of the key challenges include poor recovery of valuables and concentrate quality issues due to complex mineralogy and high ore variability, water scarcity and quality issues, high energy costs, complex environmental issues including tailings management, high capital and operating costs, worldwide constraints on resource availability, complicated regulations in emerging economies, changing demographics of mining operations with ever-changing cultural or community issues and the urgent need for a better assessment of project viability to reflect the dynamics of present mining scenario. Developing breakthrough solutions to these problems is the key to success of any new project and maintaining profitability of a mining operation. An integrated multi-disciplinary approach to problem solving is crucial along with the need for a more lateral thinking, strategic partnerships and collaboration involving the right players. This paper presents some of the key findings based on experiences from a large number of challenging projects and operations focused on solving complex metallurgical problems.IntroductionThere is a plethora of challenges in developing new ore bodies. The metallurgical complexity of these deposits has increased significantly due to the need for mining lower grade ores along with the presence of deleterious elements that have environmental and processing implications. In addition, many of the mining projects are capital intensive due to high throughput requirements to be economical along with the need for building infrastructure due to remote locations, while operating costs steadily increase due to high reagent, energy and labour costs, increased state royalties and community obligations, to name a few of the key factors. There is also scarcity of water in many regions requiring the use of sea water or brackish water, which has both environmental and metallurgical implications. The shortage of qualified technical manpower adds significantly to the woes of many mining companies. Considering these multiplicity of challenges, it has become imperative for many mining companies to be innovative in addressing these issues."

Jan 1, 2015

By L. Ozdemir

An investigation was made to determine the mechanical properties of oil shale at elevated temperatures and confining pressures, the thermal properties at elevated temperatures, and to provide mathematical models for mine design for in situ oil shale retorting. A review of current activity in in situ retorting is included with a comprehensive list of references. Tests were run at temperatures from 20°C to 500°C and confining pressures to 1500 psi with shale of 10 to 30 gallons per ton. A major loss of strength occured in heating 140°C with a partial regain from 380°C to 500°C. Higher grade shale had lower compressive strength. Elastic properties showed large variations. Brazilian tensile strength showed a similar temperature sensitivity as the compressive strength. Equations were developed for each property in terms of grade, temperature and pressure. Thermal, electrical and acoustical properties showed anomalies through the temperature range. Creep is a major factor in overall deformation of heated shale. Oil shale was found to be an excellent insulator. Loss of pillar support area at 800 hours of heating would be about 10 percent. Good correlation was found between a finite element model using the developed properties and an in situ heater test.

Jan 1, 1981

By Paykan Safe

?? Background ?? WorleyParsons Gas Cleaning ?? PT Inco Smelter ?? Process Design Considerations ?? Furnace Control and Combustion ?? Combustion Chamber ?? Spray Chamber ?? Draft Control ?? Baghouse ?? Secondary Ventilation ?? ID Fan ?? Dust Handling Equipment ?? Project Execution ?? Heat Recovery ?? Conclusion ?? WorleyParsons Gas Cleaning ? Irving, TX ?? Formerly Gas Cleaning Technologies ?? Acquired by WorleyParsons in 2005 and now part of a global EPCM company ?? 14 years experience in off-gas system design for ferrous and non-ferrous facilities worldwide

May 1, 2008

By Narasimhan K. S, Sastri S. R

A typical high silica low grade magnesite from the Salem area of Southern India, was used in studies to develop a suitable flotation system involving commercially inexpensive sodium oleate as the collector together with other reagents which can give a product of the required grade with an acceptable recovery. It was found that the presence of metallic ions such as Cu+, Fe+++ or Ca++ introduced by the addition of their salts, or by their formation with the addition of hydrochloric acid to react with magnesium and calcium carbonate in the me, can act as effective depressants for silica. The addition of 'hydrochloric acid' was found to give best results.

Jan 1, 1980

By Penrose E. K

With the exception of occasional periods, when up to 80% of oxidized ore was treated, the G.M.K. plant treated all sulphide ore until October, 1939. The treatment was, briefly, as follows:The ore was ground to approximately 17% plus 200 mesh Tyler and agitated in cyanide solution, after straking. After agitation, the pulp passed through two stages of counter-current decantation washing in Dorr thickeners and was filtered once, to complete the precyanidation stage.The precyanide filter cake was repulped with flotation circuit solution and floated in a Denver Sub A flotation machine, consisting of twelve cells. The concentrates were roasted, cyanided and filtered four times before disposal to the' dam. The flotation tailings were thickened to conserve water and pumped away to a separate dam.The average results of flotation operations for the six months before October, 1939, are shown in Table 1.

Jan 1, 1942

By M. Kwasniewski, M. Takahashi

Prismatic samples of a medium-grained sandstone from Slask Colliery (Upper Silesian Coal Basin, Poland) were tested under uniaxial compression, conventional triaxial compression and true triaxial compression conditions. The conventional triaxial compression tests were carried out at confining pressure (p) equal to 12.5, 25.0 and 37.5 MPa. In the true triaxial compression tests the minimum principal stress (s3) was equal to 25.0 MPa and the intermediate principal stress (s2) was 1.5, 2 and 2.5 times higher than s3. Results of the studies show that confining pressure strongly inhibited dilatant behavior of rock samples tested under conventional triaxial compression conditions; the increasing confinement resulted in the growing compaction of the rock material. The effect of dilatancy was also highly suppressed by the intermediate principal stress. While important dilatant, negative volumetric strain corresponded to the peak differential stress at low intermediate principal stress conditions, at high intermediate stresses the rock material was damaged to much lesser extent. As a result, faulting of rock samples in the post-peak region was much more violent and was accompanied by a strong acoustic effect. Les échantillons parallélépipédiques du grès à grains moyens de la mine ‘Slask’ (Bassin Houiller de Haute Silésie, Pologne) ont subi les essais de compression monoaxiale (compression simple), de compression triaxiale conventionnelle (compression triaxale de révolution) et de compression triaxiale vraie. Les essais de la compression triaxiale conventionnelle ont été effectués à la pression de confinement de 12,5, 25,0 et 37,5 MPa. Dans les essais de compression triaxiale vraie la contrainte principale minimale (s3) était de 25,0 MPa et la contrainte principale intermédiaire (s2) était 1,5, 2 et 2,5 fois supérieure de s3. Il résulte des essais que la pression de confinement inhibe fortement le processus de dilatance dans les échantillons testés dans les conditions de compression triaxiale conventionnelle; l’augmentation de la pression provoquait l’augmentation du compactage du matériau rocheux. Le phénomène de dilatance était également limité de façon significative par la contrainte principale intermédiaire. Alors que l’importante déformation volumique négative correspondait à la contrainte différentielle ultime avec les faibles contraintes principales intermédiaires, dans les conditions de fortes contraintes intermédiaires, le matériau rocheux subissait l'endommagement de façon beaucoup moins importante. En résultat, la rupture des échantillons rocheux au stade post-maximum était beaucoup plus violente et accompagnée d’un fort effet acoustique. Prismatische Probekörper des mittelkörnigen Sandsteines aus dem Bergwerk ‘Slask’ (das Oberschlesische Kohlengebiet, Polen) wurden unter der einaxialen Druckbeanspruchung, konventionellen dreiaxialen Druckbeanspruchung und der echten dreiaxialen Druckbeanspruchung geprüft. Konventionelle dreiaxiale Druckversuche wurden bei dem Manteldruck von 12,5 25,0 und 37,5 MPa durchgeführt. Bei den echten dreiaxialen Druckversuchen betrug die kleinste Hauptspannung (s3) 25,0 MPa und mittlere Hauptspannung (s2) war 1,5-, 2- und 2,5-mal höher als s3. Aus den durchgeführten Versuchen ergibt sich, dass der Manteldruck die Dilatanzentwicklung bei den Probekörpern unter der konventionellen dreiaxialen Druckbeanspruchung stark bremst; die Erhöhung des Druckes rief die ansteigende Kompaktion des Gesteinsmaterials hervor. Die Dilatanz wurde auch durch die mittlere Hauptspannung beschränkt. Während die wesentlichen volumetrischen, dilatanten Verformungen der Grenzdifferenzspannung bei den niedrigen mittleren Hauptspannungen entsprachen, bei den hohen mittleren Hauptspannungen wurde das Gesteinsmaterial viel weniger beschädigt. Im Ergebnis war der Scherbruch der Gesteinsproben im Post-Peak-Bereich viel heftiger und mit kräftigen akustischen Effekten verbunden.

Jan 1, 2003

By Yukihiro Ishihara, Nanase Ogawa, Ming Lei

"Abstract In the Press-in Method, a static jacking force is used to install a prefabricated pile, while a reaction force is gained from previously installed piles. This piling technique has solved problems in urban piling construction such as noise and vibration associated with the piling work, restricted construction conditions due to the existing structures, and so on, since its emergence in 1975. Its applicability to hard ground conditions has been improved, with the development of press-in machines that involve augering or rotation. Besides, information such as time, penetration depth, jacking force and rotational (or augering) torque in piling work are automatically obtained. The concept of PPT, Pile Penetration Test, has been developed by the authors, to apply the obtained information to the processes of construction planning or foundation design. This paper highlights the technique to estimate SPT N value from data acquired in standard press-in (press-in without any auxiliary methods), press-in with augering and rotary press-in. The technique will be helpful in assuring the adequate embedment depth, re-selecting the adequate press-in machine or auxiliary method, and re-pricing the project objectively, particularly when a contractor encounters unexpected ground conditions.INTRODUCTIONThe Press-in Method is one of the piling techniques that use a static jacking load to install piles. It mitigates environmental problems of noise and vibration that have been associated with other conventional piling techniques.It is also featured by its spatial efficiency; since a ‘press-in’ piling machine gains a reaction force from the previously installed piles, there is no need of bulky weights that will occupy a large space. This feature is emphasized in the piling system in Figure 1, where a press-in machine and its related devices are all positioned and ‘walk’ on top of the pile wall.Its applicability to hard grounds has significantly been improved, with some newly developed piling machines that involve augering or that install tubular piles with teeth on the base by applying axial load and rotational torque at the same time."

Jan 1, 2014

By N. W. Kirshenbaum

"The Marconaflo slurry system was originally developed to reduce costs and solve technical problems in the marine transport of mineral cargoes. In the short time since its inception, it has been found to offer economies and advantages for land-based and in-plant materials handling. This efficient method of reclaiming and slurrying particulate materials at very high pulp densities can be directly utilized in a wide variety of mineral process systems. These include: storage-reclaim applications, where even cohesive, compacted materials can be reclaimed from settled storage ""on demand""; the growing number of hydrometallurgical operations wherein slurried materials are processed to extract or yield metals; certain applications associated with pyrometallurgical treatment; and as a means of augmenting the performance of conventional mineral dressing equipment, such as thickeners.INTRODUCTIONIn the continuing effort to lower costs of producing minerals and extracting metals, the field of handling and transportation often receives too little attention from those engaged in the mining and winning of ores and metals. This comment, which pertains to ferrous and non-ferrous as well as to non-metallic producers, is especially pertinent to products having relatively low value, where transport costs can be a major portion of the delivered selling price to the minerals receiver.One method which was developed recently for the purpose of reducing costs and solving technical problems in marine transport and handling of mineral cargoes is the MARCONAFLO slurry system. A notable feature of this system is its versatility; in addition to its use in marine transport1*, some of its diverse applications have included the mining and reclaiming of tailings2 and in-plant materials handling3. As the concept and fundamentals of this system have been well explained previously4,5, the mechanics of the system will not be elaborated upon here. Rather some specific ways in which MARCONAFLO can be applied to processing and extraction will be explored."

Jan 1, 1973

Some 50 miles of tunnel have been driven in the Snowy Mountains Area since tunnelling commenced in 1951. Hates have improved progressively due to the know-how of American supervision and use of large matched equipment of modern design.The work has been carried out by contractors, working almost exclusively under schedule of rates contracts. The Authority has maintained active research into tunnelling problems, especially that of support, and this has resulted in considerable economies and improved rates of progress. The contractors also have sought economies both by management and equipment techniques. Ammonium nitrate came into favour as an explosive essentially because of its lower cost, and handling techniques have improved progressively. Rock conditions preclude use of the "Mole" type equipment in its present stage of development, but one contractor introduced the "sliding floor" and this could exert a great influence on future tunnelling methods.Examination of tunnels that have been in service for some time confirmed the quality of the work and endorsed the policy of continued research and development.GENEHALThe Snowy Mountains Scheme provides for the diversion of the Snowy and Eucumbene waters through two transmountain tunnels to the western river systems. These diversions, together with additional regulations provided for waters already flowing inland, will provide an average additional discharge of 1,818,000 ac it per year for irrigation.Furthermore, approximately 6,000 million kWh of electrical energy will be generated annually in power stations with a total installed capacity of some 3,000,000 kW (Fig. 1.).INVESTIGATIONThe aim of investigation work is firstly to collect sufficient information to allow the overall scheme to be planned and then to follow up with detailed information on eachproject. The correct balance for all aspects of this work is a matter for keen judgment, as the tunnels must be planned...

Jan 1, 1963

By John P. Davis

The use of conventional, circulatory air rotary and fluid rotary, cased and uncased drilling methods in the vicinity of sensitive infrastructure can have deleterious effects on the ground conditions surrounding and supporting structures and the structure itself. Furthermore, the use of these conventional methods offers the engineer or contractor little information about the condition of the subsurface during geotechnical applications. Conversely, sonic drilling measurements and samples can be used to evaluate actual conditions during the progress of exploration and construction across a given site. This paper will discuss the history and properties of sonic drilling and explore case histories of geotechnical applications for the advancement of boreholes within vulnerable structures and on sensitive sites for several recent infrastructure projects ? a tunnel and railroad project, a dam grout curtain project, a bridge micropile exploration project and a tunnel instrumentation project. Project summaries will discuss the advantages realized when the application of sonic drilling techniques demonstrated superior accuracy, quality control, efficiency, productivity, penetrability, waste minimization and adaptability when drilling adjacent to or within existing infrastructure. Finally, the discussion will address the current testing and application of sonic drilling to the installation of micropiles, earth retention anchors, grout injection and instrumentation installation where the quality control benefits provided by the inherent soil cores, measurement while drilling systems, accuracy and non-destructive production drilling features will be advantageous.

Jan 1, 2006

By Hamid Maleki

Prudent design of coal pillars in any mining system requires an estimation of in-situ pillar strength, overburden lateral load transfer capability, and a failure criterion. Pillar strength is typically determined using one of several different empirical pillar strength formulas. For coal reserves in the U.S., a new pillar design method was proposed based on extensive U.S. field measurements in underground mines (7) which accounted for confinement effects. Field measurements in seven U.S. seams indicated highest strength for some Utah mines where the coal seam developed high confining stresses. Lower strength was measured in structurally controlled seams. This method is expanded here including the data from the weaker tertiary coal measure rocks and lower confinement for pillars with low width-to-height ratios. The determination of how much load a pillar is expected to take is partially dependent on the ability of overburden to transfer load laterally; this is useful for selection of panel width and barrier pillars size in select mining applications where long-term stability is required in conservative designs. In caving mining systems, caving of the strata is influenced by geologic, mining and stress conditions and the released energies influences how the pillars react at loads approaching pillar strengths. Overburden deformation and caving mechanisms are analyzed in this paper in multi-panel extractions to enhance the understanding of load transfer, seismicity and coal bump control in deep western U.S. operations.

Jan 1, 2008

By James J. Olson

This report summarizes the results of a review of foreign coal mining literature conducted under the Bureau's Advancing Coal Mining Technology program. In addition to a discussion on the historical development of mechanized longwall systems, and the current state-of-the-art method in Europe, this report summarizes the previous and ongoing Bureau efforts to adapt longwall technology to U.S. conditions. The bibliographic section of this report, divided into major categories such as mine design, face management, roadway development, strata control, powered roof supports, coal winning, conveying, and automation, contains over a thousand individual entries. The purpose of this report is to provide U.S. mining engineers with background information on longwall methodology and equipment developed in foreign countries (principally Europe). The Bureau of Mines, as part of its Advancing Coal Mining Technology program, is funding R&D projects to demonstrate that the longwall mining method, successfully used in the deep mines of Europe, can boost productivity and improve safety in certain U.S. mines.

Jan 1, 1977

By William A. Enrico

Umicore acquired the Pirdop Smelter in a privatization offering by the Bulgarian government in September 1997. Since that time, an investment program has been conducted to increase capacity to 225 000 tons per year of anode copper, while improving the environmental performance to meet Bulgarian and European standards. A significant part of this investment program involved reconstruction of the three Peirce-Smith converters and the associated gas handling system. During the period June, 2000 through April, 2002, converter capacity was increased, the existing water-cooled hoods were replaced, the waste heat boiler was replaced by two evaporative coolers, the dry ESP's were rebuilt and extended, and a Converter Control System (CCS) installed. From 2002 until the present, a continuous improvement of operating and environmental performance has been achieved. This paper will describe the converter reconstruction project, the operational, maintenance, and environmental improvements achieved since then and additional projects presently under consideration.

Jan 1, 2005

By Michael A. Piepenburg

The East Side Access (ESA) Project will extend Long Island Rail Road (LIRR) into midtown Manhattan via 11 km of tunnels, a new terminal station and associated support facilities. In addition to the hard-rock tunneling currently underway in Manhattan, soft-ground tunnels in Queens will traverse beneath Amtrak?s Sunnyside Yard and Harold Interlocking, the busiest rail interlocking in North America. This paper details ESA?s coordinated approach to interfacing with both Amtrak and LIRR with regard to the planned tunnels, shafts and related construction beneath or adjacent to the operating railroads. This interface includes integration of railroad staff, extensive presentations, reviews and agreements with the railroads regarding settlement mitigation, real-time automated geo-instrumentation monitoring, ground improvement, and geotechnical/environmental controls.