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By S. H. Ash

THE INVESTIGATION of barrier pillars in the Southern field is part of the comprehensive study of the mine water problem in the anthracite region of Pennsylvania by the Federal Bureau of Mines (1, 2, 5, 6, 7, 8, 9, 10, 11, 12, 15, 16, 18).4 Tim Southern field is in Carbon, Schuylkill, Dauphin, and Lebanon Counties, in eastern Pennsylvania; has an area of 200 square miles; is 70 miles long from Mauch Chunk on the east to the Susquehanna River on the west; and is 1 to 6 miles wide. In the Southern field are 37 underground water pools containing 37312 billion gallons of water (5). Most of these pools overflow to the surface because the barrier pillars controlling them are effective under existent, conditions. Abandonment of mines in the Southern field has resulted in the hooding of 34 percent of the field. The largest tonnage of reserves of anthracite lies in this field, where mining conditions are most difficult. Large reserves of anthra¬cite underlie the abandoned mine workings, and before a great part of these reserves can be developed and extracted, the abandoned workings must be unwatered and kept drained (5).

Jan 1, 1953

By Ian Hooper, Alan Winter, Stefan Sadokierski, Craig Covil

The existing Tappan Zee Bridge was built in the late 1950s and has been working over its design traffic load for some time now. A new project, which is being jointly sponsored by the New York State Thruway Authority and Metro-North Rail Road, is looking at new alternatives to provide new road and rail crossings of the Hudson River. These include 2 to 5 mile and potentially longer tunnel crossing options that include hardrock TBM and EPBM opportunities. The paper describes the project needs and tunnel concept design work done on some of the alternatives. It also relates to the current EIS process for the project and talks about a possible double-stacked tunnel option. It also talks about the geology and environmental constraints relating to tunneling and provides and introduction to the tunnel ventilation work necessary for tunnel crossing of this magnitude. It does not report on the bridge engineering options being evaluated.

Jan 1, 2005

Differentiation of a basaltic (?) magma occurred in an active volcanic area during the late Miocene and Pliocene, and a change in the general mode of extrusion from fissure flow for the basalt to explosion for the andesite reflects an accompanying increasing magmatic viscosity. A caldera formed after the flow phase was completed and was filled with coarse agglomerate, much of which has a fused appearance. After an erosion interval its shape was modified and it became gradually deeper as repeated explosions from growing andesitic volcanoes caused large quantities of pyroclastic material to be deposited. At the close of this phase the floor abruptly collapsed when a, large block of the underlying crust was engulfed. The incompetent pyroclastics filling the caldera steepened in dip and the ensuing fractures were filled by the rising magma as dykes and sills and a chonolith formed below the caldera at a shallow depth. The ensuing activity reveals a further stage in differentiation and biotite is an important new ferromagnesian to be observed in the new rocks.Fracturing of the surrounding basalts was most intense in the rocks forming the periphery of the caldera where steeply and flatly dipping faults resulted from increasing horizontal pressure directed towards the caldera.Further differentiation resulted in the increased crystallization of orthoclase felspar, as evidenced by the numerous intrusives of trachy andesitic composition. Magmatic freezing caused mineralizers to accumulate at the top of the chonolith. These eventually escaped and auriferous pyrites, tellurides, quartz, and calcite were deposited in the surrounding rocks.The flatly dipping fractures are the most important and can be expected at various depths in a zone about 4,000 ft wide surrounding the caldera. Latest movement along these was controlled by magmatic consolidation rather than the shape of the caldera. Some flat faults were able to remain open during mineralization and acted as a feeder for the shallower fractures, thus limiting the depths to which the steeper dipping fractures were mineralized with the possible exception of one particular Nw.-striking lode (the Crown-Crescent).INTRODUCTIONThe gold deposits of the Tavua district were discovered in 1932 and from 1935 to June, 1961, 1,985,041 fine ounces of gold were produced from 4,202,504 tons of ore. Of the original three producers, only the Emperor remains active in the...

Jan 1, 1962

By M J. Nugus

The Geita gold mines in north-western Tanzania have produced 5 Moz of gold from an estimated endowment of 15 Moz. They are generally classified as typical Archaean orogenic banded iron formations (BIF)-hosted gold deposits in banded iron formations as described by Goldfarb, Groves and Gardoll (2001); Neall and Phillips (1987); Phillips and Powell (1993) and Neall (1987). The controls on gold mineralisation have been reassessed to conclude that Nyankanga, and we conclude that Nyankanga, the largest deposits within the group, developed during a dynamic and protracted deformation history intimately associated with several stages of hydrothermal fluid flow and alteration. The fluid-induced fractures associated with gold mineralisation are primarily manifested as submillimetre to metre-scale fractures and breccias developed preferentially in rocks that have been previously deformed and altered by silicification or seafloor metasomatism. This realisation detracts from the exploration and mining strategies that would solely concentrate on fluid pathways and associated wallrock alteration and veining solely within the BIFs as hosts for economic gold mineralisation.

Aug 22, 2011

By Axel Preusse

Mining subsidence plays an increasing important role in the Chinese hard coal mining. Reasons for this are a substantial rise of production during the last decade, a dense settlement in many mining regions, the increasing emergence of private residential property as well as a grown environmental awareness. German companies and research institutions hold an over more than 150 years existing know-how in all subjects of mining subsidence engineering. Due to partially comparable preconditions regarding mining depth, mining methods and geological conditions, a close co-operation between German and Chinese mining subsidence engineering experts has been in existence for some years. This German-chinese co-operation is introduced in this paper.

Jan 1, 2007

By C. Kennedy, S. Jensen

Traditionally, mineral processing plants are designed to achieve the highest recovery of valuable material with limited regard for the cost of managing waste products-both solid and water components. As an industry, we are confronting ever more stringent environmental standards and lower grade deposits requiring more intensive processing. The most profitable processing route can, in fact, lead to costly issues downstream. Issues or risks associated with waste management include water treatment and handling and storage of potentially acid generating material. The capital and operating costs of dealing with these issues are significant and should be considered as a consequence of plant design and optimisation. The authors of this paper are involved with a number of projects where process operation changes offer opportunities to mitigate risks associated with water and waste management. Examples of these changes will be discussed along with the estimated benefits to the value of the project and reduction of long-term environmental risks. Process changes include 1) the application of in-plant water treatment as opposed to dealing with the entire tailings management facility and 2) the potential to reduce metal leaching and acid rock drainage through the preferential liberation of carbonate minerals in the grinding process.

Jan 1, 2014

By D A. Cuello, G B. Sharrock

The Prince Lyell orebody at Mount Lyell Mine has a rich mining history commencing with the open pit in 1935, which transitioned underground in 1972. Between 1972 and 2014 a total of 64 Mt was mined underground as the mine extended from 210 m to 1100 m below surface. As the depth increased, three separate transitions in the mining method occurred to meet the changing geotechnical conditions, ore grade, mining costs and metal prices. The first was open stoping with pillar recovery in 1972, followed by front caving and longitudinal sublevel caving (1995), and finally transverse sublevel caving (2004 to 2014). This paper provides an overview of key geotechnical and planning milestones relating to the evolution of the mining method including underground stability, gravity flow, cavability and subsidence. Key aspects of the mine design, geotechnical parameters and rock mass response are described and critiqued with reference to observational, numerical and empirical methods.CITATION:Sharrock, G B and Cuello, D A, 2016. Geotechnical milestones at Mount Lyell Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 427–438 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Arnulf Muan, Egil Aukrust

Activities of COO in the three solid solution series COO-MgO, COO-MnO, and COO-"FeO" have been determined at 1200°C by equilibrating oxide samples with a metal phase (cobalt or a Co-Fe alloy) in atmospheres of known oxygen activities. The systems COO-MgO and COO-MnO are ideal, within limits of experimental error, whereas the system COO-"FeO" shows a slight positive deviation from ideality at the temperature of this investigation. KNOWLEDGE of activities of oxide components in solid solutions is necessary for the calculation of the cation distribution among coexisting oxide phases in many important metallurgical, ceramic, and geochemical systems. Very few activity-composition curves are available for such systems at the present time. A start on the prodigious job of obtaining such data has been made by studies of solid solutions with simple sodium chloride type structure containing NiO or "FeO" as a component.1-3 The present paper describes similar studies for solid solutions with sodium chloride type structure containing COO as a component. For the systems COO-MgO and COO-MnO, the activity solid solution is determined by the equation Here po and are the oxygen activities of the gas phase in equilibrium with the phase assemblages metallic cobalt plus oxide solid solution, and metallic cobalt plus pure COO, respectively. In the system CoO-"Fe07', the metal phase is a Co-Fe alloy rather than pure cobalt. In this case the activity of COO in the oxide solid solution is calculated from the equation where a& is the activity of cobalt in the metal phase. Because the system Co-Fe is close to ideal4 and the metal phase appearing in the present work contains less iron than cobalt even at the lowest COO concentrations of the oxide phases used may be set equal to N . Hence, Eq. [2] becomes The value of Nc, can be estimated from the relative stabilities of the oxides COO (see below) and I) EXPERIMENTAL METHOD Two different but closely related procedures were used in the present investigation to determine the activity-composition curves. In one method, the oxide solid solutions were equilibrated against

Jan 1, 1963

By James L. Vinson

Wilbur Smith Associates (WSA) has provided planning, engineering and construction oversight assistance to the Tennessee Department of Transportation (TDOT) for three construction projects intended to widen and improve segments of I-40 and associated interchanges in Knoxville, Tennessee. The projects are within the karst terrain of the Valley and Ridge Province. Subsurface conditions are characterized by an irregular rock surface coupled with differential weathering. Because of the projects? impact to local and interstate motorists, consideration was given to innovative planning, materials and construction practices that could accelerate construction. Two innovative deep foundation measures included rock-socketed pipe piles, which act as both foundations and substructure elements for a bridge?s interior bents, and the first widespread use of rock-socketed drilled shafts as bridge foundations on a TDOT project. The pipe piles were used at a site with significant cavities within the limestone bedrock. This resulted in design verification and constructability difficulties that required delays, but measures were ultimately employed to produce a sound foundation system. Over 110 drilled shafts have been constructed at sites with generally low solution activity. Relative to H-pile footings, which were included as an alternate foundation, they have apparently allowed accelerated construction at a competitive cost.

Jan 1, 2006

By George Piscsalko

There are numerous methods currently available to assess the integrity of drilled shaft and ACIP piles. Each method has its advantages and limitations. This paper will compare the various available methods as well as introduce a new method for assessing integrity of drilled shafts and ACIP piles. This new method, known as Thermal Integrity Profiling, determines the integrity of the shaft both inside and outside the reinforcing cage by measuring the hydration temperature of the concrete along the length of the shaft. These temperature measurements can be made by either passing a thermal probe through a standard Cross Hole access tube, or from embedding thermal wires within the shaft. This Thermal Integrity Profile method will be described in detail and one case history will be presented. Additional testing methods which will be compared include low strain Pile Integrity Testing and Cross Hole Sonic Logging. Advantages and limitations for each method will be discussed.

Jan 1, 2011

By A. R. Biggart

Twenty-sixth Sir Julius Wernher memorial lecture, presented at the Tunnelling '94 symposium held in London, 5-7 July 1994. In describing 18 projects with which he has been involved over a period of 36 years, the author aims to illustrate how technological change and an increase in scientific knowledge have influenced tunnelling practice, which he nevertheless maintains does continue to be an art. Tunnels discussed are: the Silver Street, Blackfriars, Whitechapel, St. Paul's and Waterloo Post Office tunnels, 1958-1969; metro tunnels on the Victoria Line, London, 1962-1970; the introduction of tunnel boring machines (TBMs), 1971-1978, in the Empingham reservoir diversion tunnels in Rutland, the bentonite tunnelling machine experiment at New Cross, the Southern tunnel water main section of the London Ring Main and the Warrington sewer in Cheshire; tunnels in rock 1975-1981, for the Lune Wyre and Megget Manor aquaducts, Weymouth sea outfall and Bristol interceptor sewer; Priestley TBM tunnels 1969-1982; the Greater Cairo wastewater project 1983-1987; Anacostia River crossing, Washington DC 1985-1987; the Channel Tunnel 1987-1992; and the Storebaelt eastern tunnel in Denmark, 1992-1994.

Dec 1, 1994

By C. Laughton

The Deep Underground Science and Engineering Laboratory (DUSEL) is to be constructed at the defunct Homestake Mine, in South Dakota. As a cornerstone of DUSEL?s research program, it is intended to conduct experiments into the fundamental nature of neutrino and proton particles. The experimental apparatus required to con-duct these experiments will be housed in large rock cavern(s) sited at depths of over a kilometer. As conceived, these cavern(s) are planned to have mined volumes of up to half a million cubic meters, and spans of approximately 50 meters. The paper will describe key end-user requirements, and outline the in situ rock conditions and mine site constraints that are likely to play determinant roles in identifying candidate sites and developing cost-effective design options(s).

By John Starkey

"During the period June 2007 to March 2007, John Starkey of Starkey & Associates (Starkey) worked in Russia for High River Gold, supervising the engineering design work that was being done at the IRGIREDMET Research Institute, in Irkutsk Russia. The work entailed moving the Newmont No. 4 mill from Elko, Nevada to Berezitovy, a mine site north and west of the city of Skovorodino, in the Amur Region of Siberia. This was a grass roots project and required construction of all phases of the infrastructure and process facilities that are associated with a 5000 t/d open pit mine and CIP mill.During the course of this engineering design exercise, many aspects of doing business in Russia were encountered, with regard to laws, norms, and business practices. This paper discusses many of these findings. Also by living in Irkutsk, many observations on Russian life and social customs were made and these merit discussion from a general interest point of view.Prior to going to Russia, another engineering and ore testing firm (TOMS) had approached Starkey to find out if Starkey could assist them in upgrading their SAG ore testing procedures to Western standards in order to offer their clients turnkey projects, that included reliable SAG and AG grinding. TOMS was aware that Starkey had invented the SPI test but did not know that the SAGDesign test had by then been fully developed and was being offered commercially as the most accurate way in the world to design new grinding mills. They were also unaware that this new testing method had been patented by Outokumpu (now Outotec) and that this method allowed them access to a design method, through Starkey, that would lead to a manufacturer’s guarantee (by Outotec) of throughput and grind for any new semi-autogenous or autogenous grinding circuit, with or without ball mills.When Starkey started working at IRGIREDMET in June 2005, they also made a request to add a design method for SAG mills that would be considered acceptable to Western clients. From these requests, presentations were made in Russian to both institutes and each decided to join the SAGDesign Consulting Group as satellite members and buy a SAGDesign test mill to use with their Bond Ball Mill Work Index mills, to provide SAGDesign testing services. To complete the service, contracts have been put in place for Starkey to use these results to design new grinding equipment and to train engineers at TOMS and IRGIREDMET how to do this work.Starkey also undertook to train engineers at both labs to go into the field and to take the samples for SAGDesign testing programs. It is here where the SAGDesign testing service upgrades other grinding test programs because the samples to be used for design are professionally chosen, and the results will be much more likely to produce a satisfactory design. Starkey is a mining engineer and is uniquely qualified to do this task. This and the SAGDesign test are the key components that lead Outotec to offer a performance guarantee for mills designed by Starkey."

Jan 1, 2008

By Alan Dahlstrand

The Jamestown Mine is a 6.3-kt/d (7000-stpd) open-pit gold mining operation located in the central portion of California's historic Mother Lode district. Most early production from the Jamestown area occurred in underground operations from 1906 through 1916. Pit production began at Jamestown in early 1987 and continued until July 1994. Although additional mineral resources existed, they were deemed to be uneconomic. About 23.3 t (750,000 oz) of gold were produced from pit operations, compared to 31 t (100,000 oz) from early underground mining. Recent operations at Jamestown included two open pits, a flotation mill and a flotation tailings facility. Flotation concentrates were produced in Jamestown and shipped to Yerington, NV for cyanide leaching in a carbon-in-pulp (CIP) circuit.

Jan 1, 1995

By Donald E. Redmon

This Bureau of Mines report examines the injury experience in the quarrying industry for the years 1968-69. Twenty-eight tables for each year are presented in which disabling work injuries are summarized by department, source of injury, extent of disability, part of body injured, and nature of injury. Correlative information on employment, worktime, and operating activity is also presented.

Jan 1, 1973

By J. Cseff

A variety of shaft and hoist equipment exists in the United States. Nearly all hoist systems are electrically driven. Machine elements which comprise the hoists and ancilliary equipment include bearings, shafting, drums, gear reducers, couplings, brakes, clutches, sheaves and electrical motors. Volume I, Systems Description, describes the various components encountered in most mine hoist and shaft installations, and brief descriptions of functions and constructions. Hoist ropes and balance ropes are specifically excluded from this report. Associated with the hoisting system is the headgear, shaft and equipment, loading/dumping facilities and the actual conveyances and their rope attachments. Volume II, Inspection and Maintenance Procedures, discusses scheduled Inspection and preventative maintenance in general terms. Preventive scheduled inspection and maintenance procedures assist in the smooth operation of mine hoisting plant, by the prevention of unscheduled or catastrophic equipment failure and its attendant downtime. Schedules and overall maintenance planning is required at the management level. Records and equipment logs must record inspection and maintenance, and unusual operations or incidents. A cross reference between MSHA regulations and various equipment components is included as part of the report. A discussion of the various non-destructive testing methods which may be applied to hoisting equipment is also included.

Jan 1, 1981

This paper describes certain analytical methods used at the Rosepery Mine and Treatment Plant of the Electrolytic Zinc Co. of Australasia Ltd., which are not generally in use and may therefore be of more interest than a description of the normal routine methods which are used in most of the mining assay laboratories of the Commonwealth, and which have been published previously.The ore mined and treated at Rosebery is of a complex nature and demands closer control in the concentrating plant than is necessary on some other similar mining fields.It is necessary for the mill shift supervisors to keep constant control on the grade of lead and zinc concentrates produced on their respective shifts, and further, it is essential to maintain an economic compromise between grade of concentrates and the recovery of the particular concent:t:ate. This necessitates a more frequent check on concentrate grade tp.an is provided by the daily assays carried, out by the assay office. Rather than employ trained ,assayers on shift work, "quick methods" of analysis, which could be carried out by the operators, 'were adopted.'In such methods, it is desirable that the necessary manipulation should be reduced to the following:-a. Taking the sample, drying and mixing.b. Weighing the necessary amount of sample-for assay.c. Adding the reagents for use in the assay without change of beakers.d. Titration and calculation.Such a contraction of, the normal technique would be impracticable for many determinations, but in the case of lead...

Jan 1, 1949

By J Shandro

This paper stems from recent multidisciplinary research between mining engineering and health researchers at the University of British Columbia and the University of Victoria, Canada. It considers the implications of a future state of sustainable mining development that places more emphasis on consideration of mine community health and sustainability within the definition of mine planning best practice. It reviews recently completed research studies on mining and other resource communities in British Columbia, Canada and a process undertaken by the research team to share research findings. It then examines the outcomes of this knowledge sharing process placing emphasis on the development of a more collaborative and enhanced mine planning process that integrates community- level indicators of health and sustainability to more effectively address mine impact-benefits. The paper concludes by discussing current initiatives that aim to benefit the mining industry, communities, and governments as they plan future mineral development projects.

Nov 22, 2011

By Tom Szynakiewicz

Micropiles are routinely used in the United States for foundation support and underpinning applications. The high capacities achievable with the use of micropiles, combined with specialty rigs for easy installation in low headroom and difficult access areas makes them a good choice for situations often encountered on existing commercial projects. The bond zone of the pile is typically drilled into a competent stratum such as sands, gravels or bedrock. In this paper, the authors will discuss a project where the lack of a shallow ?competent stratum? led the geotechnical contractor to create their own bond zone for the micropiles using jet grouting. Due to problematic clay (CH) soils, the original foundation of a six story office building in west Houston had experienced up to five inches of differential movement in-between the shallow under-reamed shafts. The owner desired a permanent solution to the problem without disturbing the majority of the tenants. The structure was underpinned with a hybrid system of jet grouted micropiles as well as jet grouting alone and the structure was re-leveled using hydraulic equipment to within a 0.25? tolerance. Design, construction and sequencing of the project are discussed in the paper. QA/QC methods are also discussed, including coring for verification of jet grout column diameter as well as a full-scale micropile compressive load test. The structure was successfully re-leveled and the entire project was completed without disturbing any tenants on the floors two through six.

Jan 1, 2008

By D. D. Hogarth

"Edward Haycock, Engineer and Public Contractor Edward Haycock was born in Shrewsbury, England, June 14, 1813. His father was John Haycock, a timber merchant and soap manufacturer, residing at Swan Hill Court, Shrewsbury, and his mother Esther was the daughter of William Hilton of Hempstead, Hertfordshire. Edward's paternal grandfather, John Hiram Haycock, was the first of a line of architects that ""changed the face of Shrewsbury"" and ""provided some of the best examples of typical Victorian architecture in Shropshire""(1). Nothing is known of Edward's early life or education, although it appears that he made no attempt to follow this artistic trend. In 1833, Edward immigrated to Canada. The following year, he married Mary Butler, daughter of Johnson Butler, a Lieutenant-Colonel in the Lincoln Militia during the War of 1812. Mrs. Haycock, as co-heiress of Johnson Butler's estate, was assigned 600 choice acres of farmland in Brooke Township near present-day Sarnia. This alone would have guaranteed a tidy income, but the Haycocks soon disposed of this land, the last lots being sold in May 1840. Instead, Haycock turned his hand to engineering and, for a number of years, was employed by the Great Western Railway first in Woodstock and later in Hamilton. He then moved to Port Hope, tried farming, worked in the engineering office of the Port Hope, Lindsay and Beaverton Railway Company, and later constructed a portion of this railway(2). During his stay in Port Hope, Haycock met his future partners Ralph Jones, a contractor, and Thomas Curtis Clarke, chief engineer with the P.H.L. and B. Railway Company. The alliance was styled Jones, Haycock and Company and their most successful venture was the construction of the Government Buildings in Ottawa. This work was the crowning achievement of Haycock's career and, no doubt, his proudest moment was at 11:30 a.m., April 2, 1860, when his daughter Mary Emily, then a little girl of 4, with a special silver trowel ceremoniously laid the first stone. Of special interest in this project were the quarrying operations, which introduced Haycock to the art and difficulties of mining as well as to the potential returns of mines. Sandstone, for facing, was drawn from four quarries, 10 to 12 miles from the Departmental Buildings. Haycock seems to have been in charge of these operations, which in the early stages involved an average labour force of 86 men and 43 teams. However, by 1861, quarrying had declined in importance and the contractors were able to concentrate whole-heartedly on the construction site."

Jan 1, 1999