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By A. T. Yu

Once exploration is complete, "winning" of the ore can be viewed as fundamentally a bulk handling proposition. Whether it is to strip, break, size, extract, load, haul, or even process, the success of each of these phases will depend upon how effectively one can utilize-the methods and tools that are available in bulk handling. Since as much as 30 to 60% of the total delivered price of raw materials can be attributed to handling and shipping (ref. 1), this expenditure may spell the success or failure of an entire mining venture. In fact, it has become increasingly evident that handling and shipping are so intimately associated with mining that only when they are duly considered throughout the mine-to -smelter master plan as an integral part of a total system can an optimum operation be expected and the most economical ton of ore obtained, this total systems approach should not only take in handling and haulage in and out of the mine, but also storage and transfer at the terminals (ref. 2,3,t), including ship and barge loading and unloading which are likewise a major consideration (ref. 5). Much has been developed during the past century in bulk handling, particularly in its expanding use in the mining industry. In view of the major role bulk handling has played and will continue to play in mining, in commemorating AIME's centennial, this paper will attempt to outline the state-of-the-art at this three-quarter point of the 20th century - one that is marked by its industrial revolution and rapidly accelerating technological advances. Bulk handling systems Although many developments in bulk handling are worth noting. The most significant during the past three-quarters of a century are: the total systems approach to solving problems, automation, the increase in speed and capacity.

Jan 1, 1971

By J. M. Goris

The U.S. Bureau of Mines, in cooperation with the Homestake Mining Co., and the University of Utah, is conducting a field demonstration to evaluate the behavior of rock masses supported with cable bolts. One of two rock masses being studied is supported with both conventional and birdcage cables. This rock mass is located between the 6500 and 6650 levels of the 45-4BN stope. 21 ledge. The second rock mass is the hanging wall of the D-limb stope between the 3500 and 3650 levels near the Ross Shaft and is supported with conventional cables. The primary objectives of the project are to monitor the behavior of the two rock masses during mining using extensometers and cable support strain gauges, after which the rock will be modeled using the finite-element code UTAH III. Field data will be used to verify the modeling. In addition. a comparison between the effectiveness of conventional and birdcage cables will be made.

Jan 1, 1991

By L. Blain

In practice, geochemical analyses can be grouped in two broad categories according to their aim. Those that seek to determine the exact chemical composition of geological materials fall under the heading of assays, whereas applied geochemistry concerns itself with the detection of anomaly contrasts. Recent trends have blurred the distinction between both approaches for many users, as methods that were traditionally used for assays are being adopted in applied geochemistry and assays make increasing use of instrumental techniques. Nevertheless. it is important to keep a clear distinction between the two types of analyses because it has immediate practical consequences, cost is the most obvious, as well as fundamental implications. In the broadest terms, the goal of geochemistry is to strike an optimal balance between throughput and accuracy, at the lowest reasonable cost, while assays strive for accuracy. Traditionally, complete silicate analysis has been the concern of assayers whereas exploration geochemists have been more interested in base metal analyses where acid extractions of the elements, without dissolution of the silicate matrix, has been the norm. This kind of distinction is less realistic now, especially with the growth in lithogeochemical studies, and some overlap in methodology is unavoidable. However, where such overlaps occur the distinction remains in the emphasis of the work. A commonly used example is that although HF acid preparations are used by both, the emphasis in applied geochemistry is on sample throughput and batch analysis, whereas assayers are more concerned with the range of elements to be determined (Thompson and Walsh, 1983).

Jan 1, 1993

By Martin Wehrli, Oliver Schneider

"MOTIVATION Tunnel construction companies must keep costs low, finish projects in less time and still meet the high quality and safety standards. Therefore, their main goal is always to optimize the tunnel excavation process. Traditional geodetical methods are used since more than 100 years to ensure an exact breakthrough of a tunnel. Evolving sensors, sensor fusion and increasing computation resources opened new fields of application for geodetic solutions in tunneling. These solutions offer new ways to reduce costs and risks in tunneling. INTRODUCTION Nowadays in tunneling, geodetical measurement methods are not only used for guidance, but also for various other applications. This paper gives an overview about where geodetical measurements are used today and highlights their benefits for safety and costs aspects. Furthermore, advanced solutions are introduced. In progressive projects, they have already become state of the art technology and are in use daily. STANDARD GEODETICAL MEASUREMENT APPLICATIONS In drill & blast tunnel construction processes, there are many standard geodetical applications used in the different construction phases, each having different requirements regarding accuracy. In the excavation construction stage, guidance tasks and setting-out of various positions is done by the foremen. Thanks to simplified measurement tools, the foremen are enabled to carry out these measurement tasks themselves without requiring deep surveying knowledge. In contrast, deformation analysis and network measurement campaigns need sophisticated planning and a profound education in surveying. Therefore, these tasks are carried out by surveyors. Profile control and as-built documentation is required in each construction phase. Depending on the requirements of the project, this task can be carried out either by the foremen or a specialized surveyor. Table 1 provides an overview over typical surveying tasks in an underground project including information about who is doing the job and the according accuracy requirements. The listed tasks are described in more detail below."

Jan 1, 2016

By Saverio Agresti, Giuseppe Lunardi, Donato Basta, Roberto Trapasso

"At a distance of 10 years from the first application of the Nazzano Method, the widening under traffic of a tube of an existing motorway tunnel was realized near Ancona, along the A14 Motorway in Italy. This paper describes the works for the enlargement with conventional method of the second tube, very close to that already widened under traffic.This enlargement was realized very fast, taking into account the advantages of some interesting technological improvements of the Final Design proved in the first tube.INTRODUCTION TO THE WIDENING OF EXISTING MOTORWAY TUNNELSThe widening of a twin-bore motorway tunnel usually considers the double option of creating a third bore as an alternative or closure to traffic of one of the two bores with the resulting reduction in the level of service for users.On the contrary, the extension in situ of a road, motorway, railway or underground tunnel in the presence of traffic, made possible by an inspired idea of Prof. Pietro Lunardi, enables the level of service of the infrastructure to be maintained without the need to resort to alternative routes to create new permanent or temporary bores, not always feasible because of the lack of the necessary space.This construction technique, known as the ‘Nazzano Method’, is part of the technologies refined and offered by the ADECO-RS approach to tunnel design and construction (Lunardi P., 2008) which is increasingly used in the world, leading to the industrialisation of tunnelling (meaning respect for the times and costs set out during detailed design) both in conventional and mechanised (through TBM) excavations.The first true experimentation of the ‘Nazzano Method’ was carried out between 2004 and 2007 to enlarge the two-bore ‘Nazzano’ tunnel (Italy, Milan-Rome A1 motorway) in the presence of traffic, widening it to house from two to four lanes in each direction (Lunardi P. et al., 2007). Following the success achieved in this first application, the Nazzano Method was strengthened considering all the possible suggestions arising from the previous experience and then taken up to enlarge the north bore of the ‘Montedomini’ two-bore tunnel (Italy, Bologna-Taranto A14 motorway), in situ and the presence of traffic."

Jan 1, 2016

By R. F. Balazik

By March 2001, shrinking global markets, reduced consumer spending and declines in domestic manufacturing and industrial output ended the longest economic expansion in US history and pushed the nation’s economy into its first recession in a decade. Aggravated by the terrorist attacks of Sept. 11, the recession led to large reductions in the domestic production of processed mineral materials. Some of the most significant production declines in the US metals industry were registered by aluminum, copper and steel producers. They faced strong foreign competition, higher energy costs and lower prices for their products. However, homebuilding and other domestic construction sectors — major users of nonmetallic mineral products such as cement, brick, glass and stone — remained strong enough to help raise the output of industrial mineral materials slightly above previous year levels. A strong US dollar continued to weaken the competitive stance of US metal and nonmetallic mineral materials companies alike against foreign producers in markets at home and abroad.

Jan 1, 2002

By H. H. Murray

In the past thirty years, there have been a large number of ownership changes in the industrial minerals arena and many medium to large companies have made industrial mineral acquisitions. Industrial minerals are exceedingly important to the achievement and maintenance of a high standard of living in the United States and in other developed countries. In the developed countries of the world the value of industrial minerals exceeds the values of the metallic minerals. In the U.S., the value of our industrial minerals is some 2 112 times that of the value of our metallic minerals. Almost every single thing we use or touch in our daily lives can be related to an industrial mineral. Examples are the construction industry, agriculture, ceramics, paper, paint, plastics, electronics, glass, petroleum, and many more in which an industrial mineral or minerals playa functional role. Industrial minerals are exceedingly diverse in their values, properties, and applications. Sand and gravel is an example of an essential industrial mineral commodity which has a low price but moves in very high volumes. Geographic location of this commodity is critical because of transportation costs. High calcium limestone or marble has a moderately high price particularly if it is white enough for use as a pigment or extender. This moves in moderately high tonnages and location is not as critical be-cause it can be shipped for considerable distances and still be competitive. Some specialty industrial minerals such as a white tale or white bentonite sells at a high price at low volumes and geographic location is not a major factor in marketing. Prices of industrial minerals do not tend to be cyclic and generally keep up with inflationary increases. Because of the diversity of industrial minerals very careful analyses of acquisitions or divestitures must be undertaken by buyers and/or sellers in order to prevent serious mistakes.

Jan 1, 1994

By D. A. Rice

As part of a cooperative effort between the U.S. Bureau of Mines and the Florida Institute of Phosphate Research (FIPR), with input-from the phosphate industry, the conversion of phosphor-gypsum to sulfur is being investigated. The proposed process incorporates a thermal reduction of phosphogypsum to calcium sulfide (CaS) and a hydrometallurgical treatment to convert calcium sulfide to ammonium bisulfide (NH4SH), which is then oxidized using a catalyst to produce elemental sulfur. The paper summarizes the results of continuing laboratory studies using an activated carbon catalyst which was loaded with sulfur through oxidation of ammonium bisulfide solution. The extraction of the sulfur that forms in situ on the catalyst is a key area in the development of the sulfur recovery process. Two approaches for removing the sulfur are being investigated: 1) thermal treatment to volatilize sulfur, and 2) leaching the sulfur using liquid anhydrous ammonia. The research has shown that it is technically feasible to recover over 90% of the sulfur from the carbon by either volatilization or ammonia leaching. Locked-cycle testing has demonstrated that the carbon has the potential to be recycled after ammonia leaching.

Jan 1, 1988

By Richard H. Olson

Talc is currently mined in the U.S. in six major districts. The size and depth of the ore bodies and their mineralogy dictate the types of products manufactured and the mining and processing methods which must be employed. The geology of the major deposits is well known and will be but briefly discussed The major emphasis will be placed upon the past history of the districts, the size and depth and configurations of the ore bodies, the ore mineralogy, and how all of these factors govern the types of mining and processing operations which may be employed in each of the districts.

Jan 1, 1984

By Smart Chika Obiora, Anthony Chukwu

Mining and processing of raw materials is one of the earliest activities of man for survival and development. The products are used for making jewelleries, metal tools, and for exchange of goods and services. However, despite the benefits of mine recoveries, it’s negative and long term effects on the environment and lives remain the point of discussion throughout the world. This study summarizes findings of researches in active/abandoned lead–zinc mines in Enyigba and Ishiagu mining districts including social surveys in the localities surrounding the mines in order to ascertain the effects on the inhabitants. Lead–zinc mining in Enyigba and Ishiagu, southeastern Nigeria has lasted for decades and has affected the socio-economic well-being of the host communities. There are evidences of soil, water, and plants contamination by Pb, Zn, Cd, and Mn in these mining communities. The mining activities also affect the overall social development of the host communities. These effects include retardation in educational development, health care provision, unemployment, and access to potable water supply. Others are rise in poverty level, social amenities, sanitary/hygiene level, high cost of living, and fertility rate. Possible mitigation strategies such as to liaising with relevant government agencies in collaboration with mine owner, mine workers, and host communities can ameliorate these negative effects and promote environmental sustainability.

Feb 24, 2023

By Hillary W. St. Clair

In a previous report 1/the author showed that the essential information from particle size analyses of grinding mill products can be represented by three or four parameters derived from the first four moments of the particle size data. These parameters may be used in gamma or beta distribution functions to estimate the weight fraction in any given size range. Moment analysis was used to study the progressive changes that take place in particle size distribution when a homogeneous isotropic mineral such as quartz is reduced in size by impact crushing. 2/ This report briefly reviews the essential features of moment analysis and describes extension of this method to size reduction by ball mill grinding.

Jan 1, 1972

By D. An, J. Withers

A nano-scale investigation has been carried out by applying an AFM (atomic force microscope) to study in situ the adsorption of various collectors, i.e., oleic acid, octanohydroxamic acid (HA), and salicylhydroxamic acid (SHA), on bastnaesite in aqueous solutions. The obtained AFM images show that the surface morphology of bastnaesite changes greatly after it contacts the solutions of the collectors, suggesting that all these collectors can effectively adsorb on bastnaesite. Increasing temperature can help increase the adsorption of oleic acid on bastnaesite. FTIR (Fourier transform infrared) results also show that all these collectors adsorb strongly on bastnaesite with a strong absorbance spectra being detected, which confirms with the results obtained with AFM imaging analysis. In general, hydroxamic acid collector (HA and SHA) adsorbs on bastnaesite mainly in the form of insoluble metal hydroxamate. This specific adsorption mechanism explains that a high selectivity with a moderate collectivity will be achieved with a hydroxamic acid collector for the flotation of bastnaesite. INTRODUCTION Rare earth metals, which are very important to modern industry, are generally extracted from numerous rare earth minerals. In practice, however, the actual extraction of rare earth is mainly from bastnaesite, monazite and xenotime. The Mountain Pass mine is one of the largest rare earth mine in the world, at which the main rare earth mineral is bastnaesite. In the past years, froth flotation has been applied to the beneficiation of Mountain Pass ore. In practice, the rare earth ore is usually crushed, milled and further separated from calcite, barite and other gangue minerals by froth flotation, in which the rare earth oxide-bearing minerals stick to aerated bubbles in the pulp and float to the surface, leaving the gangue at the bottom of the flotation cell and disposed of as tailings.(Bulatovic, 2010) In spite of the fact that froth flotation has been applied to treat the bastnaesite ore at the Mountain Pass mine, the rare earth oxide (REO) recovery is still low,(Anderson, 2015) especially compared to the one obtained with sulfide flotation. For example, the typical recovery obtained at the Mountain Pass mine was only about 70%. This may be due to the low selectivity of the collector (oleic acid). In addition, to enhance the flotation selectivity, the pulp in the mine circuit has to be heated up to 70 to 90°C and it involves a lot of energy consumption. Last but not the least, a lot of depressants have to be added to improve the selectivity of flotation process. Therefore, it is critical to re-examine the existing flotation process at the Mountain Pass mine and seek any chance of improvement. (Anderson, 2015)

Jan 1, 2019

By Bill Tucker, Mike Black

"PROJECT OVERVIEW Crossrail, Europe’s largest construction project, will increase London’s transportation capacity by 10% when it opens in 2018. The Crossrail scheme is a combination of surface and underground railway that stretches 118km east-west through central London from Reading, Berkshire and Heathrow airport in the west to Shenfield, Essex and Abbey Wood in the London Boroughs of Greenwich and Bexley in the east. Crossrail will serve 40 stations, ten of which are new, and bring 1.5 million people within 45 minutes commuting distance of London’s key central business districts. 21km of the Crossrail route comprises twin-tunnels beneath the heart of central London. It is the central section of the route, and the challenges that had to be overcome to construct its tunnels under the historic capital that forms the subject of this paper. The route of the Crossrail tunnels can be seen in Figure 1. These tunnels weave their way through the city’s underground landscape, linking eight new underground stations which connect to the existing London Underground network, providing interchanges with nine existing lines as well as the National Rail and Docklands Light Railway networks.Crossrail began construction of enabling works in May 2009 and launched the first of eight tunnel boring machines (TBMs) in May 2012. 42km of major tunneling work was completed in May 2015, and included 11km of sprayed concrete lined tunnels at the five mined stations (Bond Street, Tottenham Court Road, Farringdon, Liverpool Street and Whitechapel) in addition to the bored tunnel sections. The remaining three sub-surface stations at Paddington, Canary Wharf and Woolwich were constructed as large open boxes prior to the TBMs passing through. Crossrail, Ltd. is a special purpose company formed by the project’s joint sponsors, Transport for London and the Department for Transport, to manage design, construction and commissioning of the project. In 2009, Crossrail engaged Bechtel Ltd. as its delivery partner and a joint venture, Transcend (comprised of CH2M, AECOM and the Nichols Group), as its programme partner. The project is being managed by an integrated programme management team which is staffed by Crossrail and its partners. The railway, when opened, will be operated by Rail for London. With tunneling completed in accordance with the project’s master control schedule, the new railway is scheduled to commence dynamic testing in late 2017, with a phased opening of the tunneled sections and stations through Central London in 2018."

Jan 1, 2016

By Sean Peterfreund, Grant Finn, Ty Jahn

For urban underground development involving tieback anchors for excavation support, authorities having jurisdiction typically require tiebacks to be de-tensioned before project completion. This paper updates “A Proactive Approach to Tieback Anchor De-tensioning” (by Peterfreund and Finn, published in the 2017 RETC Proceedings), which discussed a new method employed in a cut-and-cover transit station project. Since publication of that paper, 237 tiebacks were successfully and rapidly detensioned from using a small-diameter drill to cut strands from the surface. To the authors’ knowledge, this was the first intentional large-scale use of a drilling method for this purpose.

Jun 13, 2023

By Eric Hansen, Todd Wanless, Chris Mueller, Shannon Dunne, Scott Elmer

Between 2010 and 2018, Houston added more than 1 Million residents; the third largest rate of growth in the nation. With growth, the region faces new challenges with water supply, capacity of its wastewater system, and regional drainage. While tunnel construction has been limited in Houston since the Clean Water Program of 1990s, it is about to see a resurgence to improve water supply reliability and to reduce flood risks and sanitary sewer overflows. This paper examines the challenges with “going deep” below the built urban environment and related to high ground water; stiff, fissured clays; flowing silts and sands; faults; hazardous materials; and abandoned well fields.

Jun 13, 2021

By Louis M. Schlesinger, Michael J. Garska, Joel F. Hutwelker, James T. Jr. Tanner

A pilot plant was constructed and operated to investigate the column flotation of 20 x 200 mesh North Carolina phosphate ore, using high throughput, high solids operating conditions developed at the NCSU Minerals Research Laboratory. Flotation was performed at 45% solids in a 9.5 cm (3.75 in.) diameter by 2.26 m (7.4 ft.) tall column at throughputs of 19.1 t/hr/m2 (2.0 stph/ft2) and 31.7 t/hr/m2 (3.3 stph/ft2). Recoveries in excess of 98% of the phosphate value were obtained at the lower throughput -- while obtaining concentrate grades containing over 28% P205 (61.2% BPL) at that recovery. Recoveries of about 95% of the phosphate value were obtained at the higher throughput, while making a concentrate averaging 27.6% P205 (60.3% BPL). In addition, a better understanding of the variables governing the column flotation of coarse nonmetallic minerals was gained. Variables examined included superficial air velocity, throughput (superficial feed velocity), frother type, frother dosage, and bias rate.

Jan 1, 1993

By Z. T. Mathe, M. A. Vera, M. C. Harris

This contribution presents a methodology how to quantify froth zone recovery in a continuously operated laboratory mechanical flotation cell. The methodology consists of relating the overall flotation rate constant to the froth depth of the flotation cell. As a result, a froth zone recovery factor (Rf) can be extracted. This froth performance parameter has been studied as a function of the flotation cell operating variables. By understanding the effect of these operating variables on Rf, an integrated methodology for modelling froth zone performance in batch and continuously operated laboratory flotation cells has been proposed. The Rf modelling is based on a semi-empirical approach which considers a number of parameters to be used. Some of these parameters may have physical significance, i. e. they may be easily and physically measured. The modelling approach consists of taking into account the interaction between the pulp and froth zones. This interaction allows froth zone recovery (Rf) to be predicted. The whole modelling exercise process lies on auxiliaries relationships which indicate the dependence of the parameters with the operating conditions of the flotation cell. This contribution is part of a larger project that deals with the modelling and optimisation of flotation plants (Project P9L, 2000).

Jan 1, 2001

By Thomas D. Boyce

Minewater from many western U.S. uranium mines often contains radioisotopes in concentrations higher than permissible for discharge to unrestricted areas. .Radium 226 has the lowest permissible concentrations of all radioisotopes and usually greatly exceeds this limit in untreated effluents. This radionuclide is derived from the natural radioactive decay of uranium: [ ] The treating of minewater effluents has been studied previously (1) and the classical removal method for radium has been adsorption on barytes or freshly precipitated barium sulfate. This paper describes the removal of radium from minewater by utilizing a selective complexer based on a crosslinked organic polymer matrix.

Jan 1, 1982

By Robert M. Dreyer

Thirty years ago it was possible to locate a quarry site for crushed rock for concrete aggregate by finding the nearest solid rock bluff accessible by road, But times have changed and the location of a quarry site to furnish crushed rock for concrete aggregate now has become rather complicated, Although both sand and gravel can be used for aggregate, this discussion will be confined to crushed rock in the regions around a metropolitan area. Let us assume that a consultant has been retained to advise on the desirability, and the possibility, of opening a new quarry within a given area. The problems are geological and ecological. Since the geological problems are simpler, they will be discussed first. Generally, the first step is to make a market study of competitive aggregate sources within the projected area. Assuming that the quality of aggregate to be sold by competitors as well as their mining costs will, within narrow limits, be the same, the problem becomes essentially a study of haulage costs from established quarries into the projected new area. Since haulage cannot be effected along straight lines and since each quarry operator may have different unit haulage costs, a map showing lines of increasing cost intersecting points on roads available for truck haulage radiating from competitive quarries can be rather complicated. Such a map, more-over, changes each time a new haulage contract is negotiated by a

Jan 1, 1971

By Bruce Hebblewhite

This paper focuses on the recent achievements and practices developed through the Minerals Tertiary Education Council (MTEC) initiative of the Minerals Council of Australia (MCA), in conjunction with the three partner universities involved in mining engineering education – University of New South Wales (UNSW), West Australian School of Mines, Curtin University (WASM), and University of Queensland (UQ). The collaboration between these partner universities and industry has led to the development of shared course material, cross-institutional teaching arrangements, and development of a number of flexible, distance-based delivery programs. The paper will then move on to future initiatives. Importantly, the exciting challenge is the future initiative planned to cement this collaboration by the formation of a “virtual” national school of mining engineering – Mining Education Australia (MEA). This will provide a common 3rd and 4th year program to all three universities from 2007, involving innovative teaching and learning arrangements, greater student exchange potential and a more significant input by industry into the education process. Such an initiative is not without its challenges, and has a long way to go, before becoming a reality. However, it offers greater attractiveness and marketing potential to prospective students, as well as economic efficiencies, whilst delivering a better quality, and hopefully greater quantity of graduates to industry. It can also form a launching platform for a much greater level of international collaboration, through a proposed International Mining Education Network (IMEN) which is currently being floated amongst a number of international educators.

Jan 1, 2005