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By J. J. Gusek

Several final pits in the Seneca No. 1 Surface Coal Mine were abandoned in the 1960's without king reclaimed. In addition, a progressive landslide aggravated by the abandoned mine land conditions was threatening a county mad and private property. An AML-funded project to stabilize the landslide and reclaim the final pits was completed in 1986 for the Colorado Division of Mines and Geology (formerly Colorado Mine Land Reclamation Division). The site was visited after ten growing seasons. The land is stable and the vegetation re-establishment is strong. Volunteer native plant species are now invading the reclaimed sites.

Feb 24, 1997

Gold rush histories are usually written as though they were unique events in the development of a region or nation. While this is a valid way of looking at gold rushes, it is not the only way. This paper is a brief attempt to relate the West Coast rushes to a wider context. During the second half of the nineteenth century the lure of gold transformed the Pacific Rim. Gold rushes drew more than half a million Europeans and Americans to lands bordering the Pacific. By 1900 a chain of mining, industrial and urban centres ran from California to Alaska; from Ballarat to New Guinea, and on to Western Australia. The New Zealand rushes were a significant chapter in this story. People, cargo and information passed from rush to rush. Techniques learned on earlier goldfields were imported; those developed in New Zealand were, in turn, taken up elsewhere. Administrative systems and regulations developed in Australia were implemented in New Zealand, improved and passed on to Canada. This interconnectedness was so strong that gold-seekers thought of the mining regions as a distinct culture, 'the whole digging world'. Much can be made of the similarities shared by rushes. But comparison can also highlight the individuality of each rush. +The early days of the West Coast rushes were perhaps the strongest assertion of a diggers' culture. A brief period in which a remarkable orderliness was created through mateship, self-regulation, and the occasional threat of rough justice. The West Coast rushes were both a unique experience and an integral part of a process which transformed the Pacific Rim during the nineteenth century. Understanding their part in that bigger story highlights just how unique they were.

Jan 1, 1996

By R. B. Fisher

This report gives the results of mineralogical research on the Nicaro (Cuba) nickel ores and plant products. These studies were made under a cooperative agreement with the General Services Administration (GSA) of the U. S. Government. The purpose of the investigation was to obtain fundamental data that would be useful to other GSA contractors concerned with the Nicaro ores in their research on reduction roasting, leaching, and other phases of the project; and to the metallurgical staff of the Nicaro plant in Cuba. The overall objective of the combined research was to provide data to accomplish metallurgical improvement in the operations of the U.S. Government-owned plant at Nicaro, Oriente Province, Cuba. Particular emphasis is placed on improving the recovery of nickel from the ores and on the possibility of recovering other valuable constituents, especially cobalt. This study presents the physical and chemical characteristics, mineral associations, differential thermal analyses in controlled atmospheres, and X-ray studies of the ores and plant products. The nickel ores, serpentine and laterite, were from the Ramona-Lama Mulo and Ramona ore deposits. Serpentine ore consisted of serpentine-group minerals, basic iron oxide, magnetic iron oxides, chromite, olivine, enstatite, anthophyllite, cryptocrystalline quartz, wad, and a trace of calcite. This ore contained 1.6 percent nickel, 0.05 percent cobalt, 0.86 percent chromium, and 17.4 percent iron. Laterite are was composed principally of goethite with some altered serpentine, quartz, chromite, wad, magnetite, maghemite, and hematite. It carried 1.3 percent nickel, 0.11 percent cobalt, 1.9 percent chromium, and 48.4 percent iron.

Jan 1, 1959

This Institute, by nature of its charter, draws on various persons in the mining and metallurgical world of Australasia for its President from year to year, and consequently when the presidential address is given by one of these people the topic. which they generally select is a topic to which they are accustomed and on which they are able to speak with authority.As most of you know, my prime object in life has been concerned with steelmaking, so tonight you can steel yourself to the thought that you are going to be spoken to about steelmaking.Even if that were not the case, and were I not particularly interested in steelmaking, I think it would be appropriate to look at steelmaking in a broad sense on a basis of pure metallurgical interest, because the steel industry is going through as big a revolution today as it went through something over one hundred years ago when Bessemer made a theory become a fact.Bessemer, and as the Americans prefer to think Kelly, separately conceived the idea of blowing cold air through molten pig iron, and, contrary to the then general belief, this did not result in cooling of the metal but succeeded rather in heating it, and in burning out of the rather crude pig iron the impurities which prevented it from becoming a ductile metal.For many years before this, steel had been made in a very small painstaking way by what was known as the crucible process. Benjamin Huntsman is credited with having developed the crucible steel making process to a stage where it could make a reliable and trustworthy product, but he...

Jan 1, 1961

The process of pile driving disturbs the soil around the pile. The nature and magnitude of disturbance depends upon 1) the pile size, and 2) the nature of soil. Therefore, the prediction of a single pile behavior based on soil properties of undisturbed soil samples may not match its performance. Under lateral loads, the pile may loose contact with the soil near the ground surface especially in clays. The soil pile interactions are influenced the most by pile behavior in this zone. This situation further affects the tally of prediction and performance. Piles are used in groups. The zones of overlapping stress from one pile to the other both around the pile and below their tip particularly in soft soils, contribute to group effects. Empirical solutions have been developed for prediction of the pile group behavior. The group action is more involved under vibrations. Several cases of single piles and pile groups under static and dynamic loads from published records have been analysed. It has been shown that single pile test is the best source of information on the soil-pile-soil interaction effects.

Jan 1, 1989

This paper characterizes the copper cycle, that is, the flows of copper entering and leaving the African economy over a one-year period (1994). The major flows over the entire life-cycle of copper are examined; these include production (mining, milling and refining), fabrication of semi-products and manufacturing of finished products, use, and the waste management system. The results reveal that substantial amounts of copper (of order705 Gg/yr) are mined in Africa; of that amount, about 70 per cent is exported following processing, 18 per cent is utilized by African fabricators, and 12 per cent is discarded. The flows of copper products from African fabricators and product imports from other continents exceed product discards by large amounts. This difference, about 0.25 kg Cu/capita/yr on average, is added to in-use stock, largely as wire, plumbing tube, and in electronics. Some 65 per cent of the copper in discard flows is contained in electrical and electronic products, where it is relatively easy to collect and process for reuse. About a third of the copper discard flows known is recycled. The actual percentage is almost certainly higher because of informal (and unrecorded) recycling. Much of the remaining discarded copper is diluted into the municipal waste stream, where recovery and recycling are probably not economically justified. Keywords: material flow analysis, resource management, material budgets, copper, stocks and flows, systems analysis, Africa, developing country

Jan 1, 2003

By E. F. Schnitzer, P. J. Wampler

During 1996 and 1997, Oregon experienced flooding on a scale not seen in many years. Some gravel pits located near rivers experienced erosion and, in several cases, breaches between the gravel pit and the river. Initial evaluation of several sites that experienced breaches indicates that impacts to the river system are complex and vary significantly from site to site. The impacts to the adjacent river system may be viewed as both positive and negative. Several floodplain-mining sites in Oregon located in areas of historic river flow have reverted to active riverbed. In many cases, state and federal fisheries biologists and university researchers see the resulting increase in channel complexity and habitat as favorable. The Oregon Department of Geology and Mineral Industries – Mined Land Reclamation Program (DOGAMI-MLR) is performing additional studies of the impacts to the off-channel areas that resulted from the 1996 floods. More data is needed to make sound floodplain decisions regarding mining.

Jan 1, 1999

By K Lownie, R Sani, A Sianturi

Part of the PT Freeport Indonesia (PTFI) mine production is in the process of transitioning from the deep ore zone (DOZ) mine to the deep mill level zone (DMLZ) mine. The DMLZ mine is the next lift in the caving series and lies 500 m below the current DOZ footprint.In order to reduce the need for a very expensive additional ventilation system for the DMLZ mine, it was decided to reconfigure some infrastructure and upgrade the performance of the three existing DOZ mixed flow ventilation fans in situ, reducing the new fans required to two. This was far less costly than providing complete new installations.These fans are installed in individual underground chambers in DOZ mine exhaust drifts and connected to the DMLZ mine exhaust drifts system in 7 m × 7 m airways size, through sets of 6 m diameter by 500 m high raises.The upgrade process involved replacement of motors, fan shafts and bearings. The existing 1600 kW DOZ mixed flow fans are 3500 mm diameter and operate at a speed of 595 rev/min and were originally designed to deliver 390 m3/s at 3.3 kPa. Efficiency optimisation may be required at a later date.The upgraded DMLZ fans are required to deliver 425 m3/s at 3.7 kPa and it was necessary to increase in motor size and speed to 2200 kW at 710 rev/min. This paper will discuss the fan upgrade project and in particular the integration of an unusual ventilation system, which is based on the semi parallel operation of multiple large fans.CITATION:Sani, R, Sianturi, A and Lownie, K, 2017. Operation of deep mill level zone mixed flow fans after the first fan upgrade – a parallel fans case study, in Proceedings Australian Mine Vent Conference 2017, pp 285–292 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Parviz F. Rad

This Bureau of Mines report reviews laboratory and in-mine techniques for determining mechanical properties of coals, with special emphasis on the relationship between these properties and the minability of coal. An extensive bibliography is included.

Jan 1, 1973

By J R. Leeming

Mines require ventilation to ensure an adequate atmosphere for the sustenance of life, and to dilute, render harmless and remove contaminants.This paper describes the developments in the United Kingdom (UK) from natural ventilation, through the introduction of fire and simple fans, to modern fully independent and remotely monitored and controlled installations.CITATION:Leeming, J R, 2017. The history of mine ventilation in the United Kingdom, in Proceedings Australian Mine Vent Conference 2017, pp 271–276 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By A N. Kasnanto, D A. Sims, J Pocoe, B Pulungan

In this case study we compare the sampling quality of diamond drilling (DD) and reverse circulation (RC) drilling at the high sulfidation Purnama gold–silver (Au-Ag) deposit located in northern Sumatra, Indonesia.There was a systematic bias of 23 per cent gold metal under-call in the diamond drilling based Ore Reserve estimate compared to the mill reconciliation over three years of production. The RC based Grade Control data and mill production data were in much closer accord. Investigation led to quantification of the significantly reduced sampling imprecision (or improved precision) of RC drilling samples relative to diamond drilling samples and the determination of a grade bias between the drill types caused by sample volume and metal distribution in the mineralisation. An infill RC drilling program was undertaken to improve data density across the pit for inclusion in the Mineral Resource estimate. This subsequently increased Au metal in the estimate by 16 per cent.The sampling imprecision of primary diamond drill sampling is rarely tested. Duplicate sampling can be used to quantify sampling imprecision at each stage of subsampling. In diamond drilling it is tested at the primary sampling stage via second half core sampling, while RC sampling is tested with field duplicate sampling at the rig. Duplicate data can be compared in a number of ways to determine imprecision including Thompson-Howarth plots which quantify imprecision to allow comparison between different methods and protocols. Comparing sampling imprecision between data sets and data types allows determination of optimum drilling and sampling protocols and can reflect upon the underlying validity of Mineral Resource input data and estimation outputs.CITATION:Sims, D A, Pocoe, J, Kasnanto, A N and Pulungan, B, 2017. Why combine reverse circulation and diamond drilling in Mineral Resource estimation at Purnama?, in Proceedings Tenth International Mining Geology Conference 2017, pp 413–422 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By R. R. Lowery

This project was proposed to provide information on the hazards associated with arc melting of thorium. A general air-sampling analysis was made to determine the separation, concentration, and distribution of thorium daughter (decay) products throughout arc melting, machining, and forging processes of a thorium handling facility. The value of well coordinated health physics program is stressed in connection with potential health hazards and personnel protection. Building, equipment, and exhaust ventilation requirements for such a facility are discussed. Special handling methods are described for thorium. INTRODUCTION The Bureau of Mines at the Albany Metallurgy Research Center has been involved in handling the naturally radioactive metals, uranium and thorium, for several years. Cooperative work for the Atomic Energy Commission has been carried out with thorium metal, and as a result the concerned laboratories of the Center have accumulated experience on the hazards associated with this metal. This report details the radioactive hazards arising from the arc melting, machining, and forging of thorium.

Jan 1, 1962

By Liang Shen

The Cooper River Bridge, the longest cable-stayed bridge in North America, replaces two existing bridges along U.S. Highway 17 and connects the City of Charleston and the town of Mount Pleasant, South Carolina. Two diamond shaped towers support the 1,546 ft long main span over Cooper River and allows for a 1000 ft wide navigation channel. The Charleston high-level approach is 4351 ft long and provides a 250 ft wide navigation channel for Town Creek, while the Mount Pleasant high-level approach is 2,090 ft long. Due to the high seismicity in the region, potential vessel impact, and hurricanes, large lateral loads are expected. From various types of foundations, 10-foot diameter drilled shafts were selected for their high capacity against vertical and lateral loadings. The shafts are founded on a stiff to very stiff lightly cemented calcareous sandy clay or sandy silt layer, called Cooper Marl, which underlies the coastal sediments of the interbedded clays and sands. A group of 11 shafts supports each main tower, while a rock island protects it from vessel collision. A group of 4 to 8 shafts foundations support the other piers of the main span unit. A pair of shafts supports the High Level Approach piers. The shaft tip elevations vary from 120 ft to 230 ft below water line. An elaborate geotechnical investigation was conducted on the site, including a load test program on full-scale shafts under axial and lateral loads. The results of the tests were used to calibrate the lateral and axial soil resistance. The objective of this paper is to present the different aspects of the bridge foundation design.

Jan 1, 2013

By H. A. Dierks

Implementation of the joint Federal-State control program established in 1955 to cope with the mine water problem in the Pennsylvania anthracite region is described in this report. The increasing severity of the water problem in the anthracite mines has necessitated major adjustments as this continuing program has progressed. Since 1941 the Federal Government has recognized the mine water problem as an important factor in the worsening economic condition of the anthracite region by initiating scientific and technologic investigations and establishing the Anthracite Flood-Prevention Section in the Bureau of Mines in 1948. On the basis of comprehensive investigations and studies, the results of which were published in numerous reports and bulletins, the Anthracite Mine Drainage Commission of the Commonwealth of Pennsylvania formulated a plan that served as a background for legislative action in 1955, resulting in Public Law 162, 84th Congress (Act of July 15, 1955 (69 Stat. 352; 30 U.S.C. 571-576)), for the Federal Government, and Act No. 82 of the General Assembly, July 7, 1955, for the Commonwealth of Pennsylvania. The report covers 29 mine flood control projects approved and executed in implementing the aforementioned legislative acts. Essential engineering and cost details for each project are given, together with an evaluation of the effect that the installed facilities have on alleviating the mine water problem as it concerns individual mines and the anthracite industry as a whole.

Jan 1, 1962

By Klaus Rieker

Over the last 30 years Wayss & Freytag Ingenieurbau AG has gained a lot of experience in mechanized tunnelling on various major projects. During this period most important developments concerning the machine technology for EPB- and Slurry-Shields have taken place. Since the first application of a hydro shield for the Wilhelmsburg Collector project in Hamburg in the early seventies, several stages of development have led to the current state-of-the-art in mechanized tunnelling. The continuous improvement of TBM techniques allows the execution of high quality tunnelling, particularly with regard to maximum safety and efficiency. The practical experience of the construction companies is of essential importance in order to continue further development and improvement.

Jan 1, 2005

By Marco Sonnenschein

As time is costly, engineering companies have developed methods, procedures and mechanical equipment to tunnel faster. But the best excavation method will not be able to cope with the time pressure if there is not a reliable backup system. Therefore, the application of belt conveyors for tunnel boring machine (TBM) drives as well as for drill-and-blast driven tunnels assure a quick and smooth removal of excavated soil in order to enhance the efficiency of the tunneling equipment. During the last 10 years, belt conveyor systems have achieved ?state-of-the-art? levels and have become the first choice for muck removal systems in both TBM and drill-and-blast driven tunnels. Because time has become such a key criterion in tunneling projects, it is essential that all equipment is operated so as to derive optimum efficiency and minimize costs. Efficiency also means to think about new tasks for existing technologies.

Jan 1, 2012

By Fritz Grübl

Modern shield TBMs allow tunnel drives through almost any type of ground. Thanks to high elaborated technical measures, significant subsidence of the ground surface can be almost entirely avoided. The tunnel lining behind the TBM must be capable of withstanding all loads without deforming, especially during ring erection and advance. Single-shell tunnel linings behind the TBM, usually reinforced concrete segmental rings, can be designed to fulfill this demand. With many projects, however, damage occurs to the lining. Repair costs may be extremely high. Reasons for damages and possibilities to avoid them are shown and explained.

Jan 1, 2001

By Stephen M. Smading

Unique onsite assembly of a 12.43 m Main Beam TBM and back-up system was completed on September 18, 2008 in the remote mountains of the Sichuan province of China. The equipment was assembled onsite, without previously having been assembled and tested in a factory, utilizing a method called Onsite First Time Assembly (OFTA). The Jinping-II hydroelectric project features four parallel headrace tunnels approximately 18 km long, two of which will be excavated by TBMs and two by drill and blast. A nearby fifth tunnel is being excavated by a 7.2 m TBM to draw down ground water in advance of excavating the headrace tunnels. This paper addresses the following topics: ¦Project description including geology and terrain; ¦The decision process leading to onsite first time assembly, the assembly process and logistics, and lessons learned; ¦Design features of the TBM and back-up system; and ¦Operational history from startup to the writing of the paper.

By Gui DeReamer

Located on the Wabash River in the central portion of the state, the city of Lafayette, IN is relatively small compared to most cit-ies that incorporate tunnels into their combined sewer overflow (CSO) systems. The original CSO plan for the city was to replace two aging lift stations that were built in the 1950s. The original con-cept was to build a new sewer using conventional cut-and-cover construction to eliminate one of the lift stations ? the Parking Lot Lift Station ? and build a new regionalized one at the location of the Pearl River Lift Station. The initial sewer design was sized just to handle the flow that would eliminate the Parking Lot Lift Station. The planning for this project was being developed as part of the city?s CSO long-term control plan (LTCP) that focused on reducing the overflows from the city?s 14 overflow points. However, during the development of the CSO LTCP, a major industrial user indicated it would be increasing its flows to the system, which required additional conveyance capacity to meet the city?s CSO LTCP. After reviewing the design concepts with city representatives during the planning phase of the project, the mayor indicated that he wanted to minimize impacts to downtown businesses; therefore, trenchless alternatives were considered. The last piece of the puzzle that drove the project away from a small diameter pipeline was discovered during a flow monitoring program to collect flow data for the CSO LTCP project. This study revealed a major restriction in the 100-year-old Pearl River Trunk Sewer, located beneath four active railroad tracks. To eliminate this flow restriction, provide more overflow storage and reduce the impact to local businesses, a new 2.7- to 3.6-m- (9- to 12-ft-) diameter tunnel sewer became the most viable solution.

Jan 1, 2011

Newmont Gold's methods for deposit modeling vary, depending on geology, mining and processing methods, economic feasibility and availability of historical information. It is argued that successful modeling requires understanding these factors, knowing the strengths and weaknesses of the various modeling techniques and being flexible in selecting the appropriate methods. Newmont is one of the world's largest gold mining companies, with operations in the United States, Peru, Mexico, Indonesia and Uzbekistan. And it is active in exploration worldwide. At the end of 1996, Newmont declared a total reserve of 1.15 equity kt (37.1 million equity oz) of gold and 2.17 equity Mt (2.39 million st) of copper. The gold deposits managed by Newmont totaled 752 Mt (829 million st) of ore containing 1.28 kt (41.3 million oz) of gold averaging 1.71 g/t (0.05 oz/st). In addition, Newmont is developing a porphyry copper-gold deposit that totals 9.1 Gt (1 billion st) of ore containing 380 t (12.1 million oz) of gold and 4.82 Mt (5.32 million st) of copper. (In May 1997, Newmont Gold Co. merged with Santa Fe Pacific Gold Corp., thus increasing Newmont's reserves to 1.72 kt or 55.2 million oz of gold and 2.17 Mt or 2.39 million st of copper.)

Jan 1, 1998