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By Francis Church Lincoln

"INTRODUCTION During the period from September 18 to November 27, 1944, the Bureau of Mines conducted an investigation and exploratory churn-drilling program in an area immediately north of the Crow Branch Diggings, a district lying approximately 2 1/2 miles southwest of the town of Livingston in Grant County, Wisconsin.The work was undertaken as part of a general Bureau of Mines investigation of the zinc-producing area of southwestern Wisconsin at a time when all effort was being made to increase the production of metals important to the Nation's war prrgram.Although no mining has been done in the district in recent years the Crow Branch Diggings were an important source of galena and may be found today in the dumps remaining from old surface-mining operations.The Bureau of Mines undertook an exploratory churn-drilling program on the northwestern projection of the general strike of the digging in a zone where subsurface,lead and zinc mineralization had been reported from drilling done in the early 1900's."

Feb 1, 1947

By Peter Faust, Jeremy Zorne, Timothy Siegel, Diane Fiorelli

Professional sport venue construction follows a very simple rule. Once the decision has been made to move the team to a new place, construction shall begin immediately, so that not more than one or two seasons pass by stuck in the old home. Such tight construction schedules require a different approach than traditional design-bid-build contracts. Design is mostly done on the fly, the construction schedule becomes a main risk factor and an early contractor involvement is desired. As specialty contractors become more and more sophisticated, owners, their construction managers or the general contractor have realized the value of ideas and modern technology they can bring to the table for a successful and fast project completion. Local knowledge and experience in a variety of solutions play a key role in the specialty contractor’s ability to provide added value to the project. This is also true for the specialty foundation contractor, who needs to understand the complexity of such modern structures from its integrate foundation, over the delicate concrete structure to a potentially fancy movable stadium roof. Not to mention all the modern high tech equipment which shall make such a place a great customer experience. His expertise shall enable him to propose the most suitable foundation element for the given ground condition and application. Rather to build what others have designed, his strength is to propose alternate concepts which will be faster and (hopefully) more cost effective. This paper highlights different value engineering (VE) input a specialty foundation contractor had on 3 major sports arena projects in California. Together with the entire team from owner to GC, including the Geotechnical (GEOR) and the Structural Engineer of Record (SEOR), the most efficient and best performing foundation solution can be found every time. But such an approach also requires the open mind of the owner to entertain last minute changes when the permit drawing set has already been submitted for approval.

Jan 1, 2018

By M Stevens, M P. Simpson, J L. Mauk

The Karangahake deposit was the second largest producer of gold-silver bullion in the Hauraki Goldfield, New Zealand. New mapping of a 2 + 3 km (6 km2) area demonstrates that hydrothermal alteration surrounds productive veins. Wallrocks proximal to veins are intensely altered and alteration decreases toward the margin of the system.   At Karangahake, distinct zonation of adularia, calcite, epidote, illite and illite-smectite surrounds gold-bearing lodes with unaltered rocks containing magnetite and plagioclase occurring on the margins. Adularia, illite, illite-smectite, and calcite zonation defines hydrothermal alteration extending 2 km to the east of productive lodes. Epidote and adularia zonation occurs proximal to veins. The adularia zone compares well to potassium/thorium studies conducted in the area. Illite zonation is well developed to the east of the veins grading into interstratified illite-smectite containing 5 to 40 per cent smectite 1.5 km from the Maria Lode. Calcite is restricted to the east of the study area occurring in 18 per cent off surface samples. Less altered rocks containing plagioclase and magnetite occur distal to veins. The magnetite occurrence compares well to aeromagnetic studies conducted in the area.   Adularia and coexisting adularia and albite indicate the host rocks were highly permeable. Epidote, illite, illite-smectite and previous fluid inclusion evidence implies temperatures graded from >240¦C in the core of the system to approximately 150¦C on the periphery. The alteration association of quartz, adularia, calcite, pyrite, chlorite, illite and illite-smectite reflects a near-neutral to weakly alkaline water. Calcite occurrence and the absence of zeolite imply the fluid contained significant dissolved CO2.

Jan 1, 2005

By Xi Zhang

A technique for fabricating free-standing, high-aspect-ratio porous and pillar-type Ni structures has been developed using wet Si processing. A wafer of (100) Si was initially etched in HF solution to form deep pores with micron-sized diameter. The aspect ratio can exceed 200. By introducing the as-etched Si into a defined aqueous Ni2+ solution, Ni deposits grew rapidly onto the sidewalls and replaced the Si. Long-time immersion allows the Si sidewalls to be completely converted and thus form a metallic Ni structure with high-aspect-ratio pores. It is known that close-packed submicron Si pillars can be formed by oxidizing and subsequent etching of the macropore sidewalls. Treated in the same Ni solution, high-aspect-ratio Ni pillars were correspondingly emerged by replicating the original pillar-type Si structure.

Jan 1, 2006

By A. C. Smith

The U.S. Bureau of Mines constructed a large-scaJe facility to study the self-heating of a large coal mass under conditions that simulate a gob area of a mine. The insulated coal chamber can hold up to 13 short tons (st) of coal and is provided with a forced ventilation system and computer-controlled temperature and gas measurement systems to monitor the heat and mass transfer phenomena that occur in the coalbed. Three experiments were completed with high-volatile C bituminous coals that exhibited high spontaneous combustion potentials in laboratory-scale tests. In the first two tests, a sustained heating was not achieved. In the third test, temperatures throughout the coalbed increased steadily from the start, with thermal runaway occurring near the center of the coalbed after 23 days. The thermal reaction wne then moved toward the front of the coalbed. The results of these tests showed that the self-heating of a large coal mass depends not just on the reactivity of the coal, but also on the particle size of the coal, the freshness of the coal surfaces, the heat-of-wetting effect, and the availability of O2 at optimum ventilation rates.

Jan 1, 1991

The offshore Maui gas/condensate field was discovered by Shell BP and Todd on Services Limited in 1969. Subsequent appraisal drilling and negotiations with the Government led to a development agreement, æThe Maui White Paper' being concluded in 1973. Part of this agreement provided for the Government to take a 50 per cent shareholding in the field. The field is comprised of a double domed anticlinal structure containing two gas reservoirs at depths ranging from 2700 - 3000 m. Water depth is 110 m. The development plan called for two standalone steel platforms to be installed sequentially over a period of some years depending on gas demand. The first platform (MPA) was put in place in 1976 but difficulties were experienced with piling and drilling of the 12 (later increased to 14) wells did not start until 1978. First gas was piped ashore late in 1979.

Jan 1, 1994

When the HSE Act was introduced in New Zealand in April 1993, one of the prime aims of the Government was to signal to the industry. The Government's recognition of the employer as the key person responsible for safety and health in the workplace and to actively encourage employers to self manage the health and safety function. Because of the significant change in the philosophy behind the new legislation, and because of the inherently conservative nature of the mining industry, it has taken some years for both the industry and the regulators to reach the stage of considering the framework in which a controlled degree of self management can proceed.   In this paper, some of the issues relating to the legitimacy of the process are considered, some of the questions raised in the minds of those charged with implementing the legislation are discussed, and the views of some eminent authors are examined.   The latter part of the paper focuses on a programme called the Reduced Site Surveillance Programme, which grew out of Goal 2 of the New Zealand Mining Inspection Group's 5-Year Strategic Plan. The programme is described in some detail, and the criteria applied at each stage of the programme is discussed. The paper concludes with the author's expectations of the longer term outcomes of the programme.

Jan 1, 1997

The Ocean Drilling Program (ODP) is the largest international geoscience project in the world, and the state-of-the-art drill ship, the JOIDES Resolution, is permanently at sea. Each year there are six scientific cruises (legs) which each last approximately two months. These legs are designed by geoscientists from the nineteen countries that subscribe to ODP.Australia and Canada presently share ODP membership under the banner of the AUSCAN Consortium. The benefits of Australia's involvement in ODP include internationalisation of Australian geoscience, advanced graduate training, and unique scientific investigations of the ocean floors in the Australasian region. In addition, visits to Australian ports by the ODP drill ship, the JOIDES Resolution, contribute up to $2 million per visit to the local economy. Amongst the many other aspects of ten years of scientific drilling, OOP has significantly contributed to our understanding of hydrothermal processes on the seafloor. To date, three hydrothermal sites have been drilled to date by the OOP, Snakepit (MAR), Middle Valley (Juan de Fuca Ridge) and TAG (MAR). Two more hydrothermal sites are scheduled for 1996.

Jan 1, 1995

By J. R. Thoenen

[For several years the Bureau of Mines conducted tests on ground vibration t emanating from quarry blasting in an effort to determine an index of destruction for different types of structures. Results of these studies have been published in four Bureau of Mines Reports of Invitations as well as in several articles in the trade and technical press.5/ The first paper (3)6/ discussed the subject in general and gave results s of a few blasting records. Some tentative theories also were advanced. The second paper (4) discussed results s of records made from blasting in a number of quarries.]

Jan 1, 1940

By Eric G. Kok

Complying with respirable dust standards is presently a critical problem for many longwall faces equipped with double drum shearers. Results are presented of research performed to increase the quantity and optimize the distribution of the water supplied to the shearer drums to control the shearer operator dust exposure. The effect on the total respirable dust produced by the shearer was also examined. During the research effort, a simple and inexpensive manually controlled valve system was designed and implemented on a shearer to distribute the water supplied to the shearer drums. Research showed that increases in water quantities are beneficial but associated pressure increases may induce respirable dust boilover negating potential advantages. Other essential parameters such as location of shearer operator, outside spray orientation and air quantity were considered in the evaluation.

Jan 1, 1986

During a programme to determine the suitability of the UK site for deep disposal of radioactive wastes, geostatistical methods were used to characterise rock heterogeneity on the basis of seismic and wireline acoustic-impedance data. The data were analysed to yield semi-variogram models that quantified the three-dimensional spatial heterogeneity of acoustic impedance. These models were reconciled with geological interpretations of the area and used to generate simulations of acoustic impedance, with wireline acoustic impedance as conditioning data. The three-dimensional simulated images were compared with actual seismic acoustic impedance. The variography confirmed a vertical zoning effect in the Borrowdale Volcanics, showing that it is caused by preferential clusters of high acoustic impedance values corresponding to regions of relatively low porosity. The method provided realistic three-dimensional models from sparse, one-dimensional wireline data

Jun 19, 1905

By Joseph L. Margin

From a stubborn start to record setting performances in little over a year, that is the story of the English Running Tunnel Boring Machines. The program to transfer technical information on these highly advanced machines from builder to user will be discussed as a vital link to this accomplishment. Some interesting features of these machines will be covered as well as a recounting of the various conditions that were encountered during these drives and how they were resolved.

Jan 1, 1991

By A. Duerksen

Surface coal mining in West Virginia has supplied energy to the eastern coast of the United States for over a century. The coal mining industry has been forced to adapt as societal demands regarding health, safety, and environmental impacts have changed with time. More recent pressure has called for another iteration of change: long-term post-mining sustainability. The research presented in this paper investigates one potential solution?or component of a solution?to improve mining sustainability in Appalachia: post-mining wind power. This paper intends to demonstrate and explain the feasibility of synergistic mine closure and wind development. Wind conditions at three reclaimed mine sites in West Virginia were monitored in order to develop representative case studies for post-mining wind power. This paper contains a summary of the literature consulted to plan the site assessments, the methodology employed to execute them, the analysis steps undertaken to derive conclusions, and a discussion of all findings. This research has found that significant cost savings can be yielded from synergistic mine closure and wind development, as compared to greenfield wind development. Though wind conditions themselves remain the primary driver for site feasibility, post-mining wind power is a practice with significant promise for improving project economics, contributing to renewable energy development, enhancing company-community relations, providing local employment opportunities, and exemplifying sustainable business practices in Appalachia.

Jan 1, 2012

By G. P. Halliwell, C. R. Austin

The investigation described in this paper deals with the development of high-temperature alloys of the Konel series over a considerable period of time at t,he Research Laboratories of the Westinghouse Electric and Manufacturing Co. The word ''Konel" has been coined to designate a class of alloys which are essentially nickel-cobalt-iron with other elements added, usually in small quantities. Most of these alloys contain titanium, usually about 2.5 per cent. The main consideration related to strength at high temperatures but the thermionic characteristics of the alloys was also of considerable importance. It is, however, with the mechanical properties at elevated temperatures that we are herein concerned. Much attention has also been devoted to their age-hardening characteristics. There is little need to stress the utilitarian aspect of this subject, as it has been discussed frequently. Alloys exhibiting superior properties at normal or elevated temperatures rapidly find many suitable applications. There may be some question, however, as to what constitutes a "superior alloy," or an alloy that may have good service possibilities at high temperatures. The problem is complex and various means have been employed to predict the useful life that may be expected of a material. In recent years the "creep limitJ' has been used as the best means of evaluation. Such tests necessarily are prolonged and hence collection of data is very slow. In a general survey of many alloys therefore the creep test is not desirable and recourse must be had to much shorter time tests in order more rapidly to select alloys which appear to show promise. For this reason the present survey has been made using the high-temperature tensile test and a bend test developed by Howard Scott.' In the tensile test the conditions have been standardized for all tests, so that values obtained are at least comparable, one alloy with another, although the absolute values recorded merely indicate the mechanical properties at the given temperature under a definite rate of loading.

Jan 1, 1932

By Nathan W. Iverson, David S. Graham, Paul J. Axtell

"The Highway 53 relocation project in Virginia, Minnesota, involves construction of a very tall bridge across a currently inactive iron ore mine pit. The inactive pit is partially flooded and serves as the community’s drinking water source. The 1,132-ft long new bridge is a three-span, plate girder structure. Two intermediate, approximately 200-ft tall piers are located within the pit.The foundations for the two piers consist of groups of 30-in diameter piles which, despite the contradiction in terms, are essentially very large micropiles. Extremely challenging and highly variable subsurface conditions exist at the site, ranging from uncontrolled iron ore mine waste fill to some of the hardest rock on earth that can also be highly fractured and abrasive. Despite the conditions, large diameter (30-in) micropile foundations up to 175 ft deep were successfully installed using down-the-hole hammer methods and full-length permanent casing under an extremely aggressive construction schedule.Full-scale foundation load testing using the Statnamic rapid loading method was also conducted in support of the design and construction but under a separate pre-design phase contract. This paper describes the unique aspects of this foundation project, including design, construction, and load testing of the large micropiles.INTRODUCTION AND BACKGROUNDIn 1960, a segment of Trunk Highway 53 (TH-53) in Virginia, Minnesota, was built on land owned by iron ore mining interests. As part of the roadway easement agreement, Minnesota Department of Transportation (MnDOT) was to be given notice three years prior to termination of the easement. In 2010, MnDOT received notice that the mining interests wished to access the ore. Through negotiations in 2010, MnDOT and the mining interests agreed to a 2017 date for abandoning the existing section of roadway. During this period, MnDOT needed to procure project funding, satisfy environmental permitting requirements, and acquire new right-of-way to permanently reroute TH-53 and keep it open to traffic. This was no easy task due to the existing mine pits surrounding the area.The E-2 alignment option shown in Fig. 1 was ultimately selected for the rerouted highway in 2014. The new highway segment includes a three-span bridge across the currently inactive Rouchleau Mine Pit. The inactive pit is partially flooded and serves as Virginia’s drinking water source. The 1,132- ft long new bridge is a three-span, plate girder bridge. Two intermediate approximately 200-ft tall piers are located within the pit. Fig. 2 is a conceptual rendering of the bridge."

Jan 1, 2017

By Y. Q. Zhang, S. S. Peng

Numerical modeling was used to design the pillars and bolting plan for a mine with weak roof and multi-seam stress condition. Previous mining experience, pillar/roof yielding and in-situ horizontal stress were considered in the models. By modeling the upper seam yielding and vertical stress transfer, a multi-seam influence zone was obtained. Appropriate pillar sizes were designed for conditions with and without upper seam stress influences. Roof support for the track and belt entries, using fully-grouted resin bolts and cable bolts, was proposed and implemented in the model. The bolting plan was evaluated under the weak roof condition.

Jan 1, 2004

By David Arana

The use of gas-water dispersion of a molten material flow onto a vibrating surface is developed as a process to minimize water pumping requirements, minimize the risks of explosions, and minimize the post solidification dewatering and fines handling equipment requirements. The process uses existing vibration transport technologies and common plant utilities. Plant trials using the smaller footprint and the progressive molten particle cooling time have yielded encouraging results. The results are analyzed and reported.

Jan 1, 2006

By W. M. Dressel

In producing feed for a lead blast furnace, concentrates analyzing 70 to 80 pct Pb are sintered to produce a physically acceptable low-sulfur product which contains only about 50 pct Pb. Mixtures of PbS with varying amounts of SiO2, CaO, Fe 20., and ZnS were heated in an oxidizing atmosphere at 1,000° C; the products were cooled and examined to determine the problems involved in producing sinter with substantially higher lead levels. Microscopic and electron microprobe studies of the above products as well as experimental and commercial sinters indicate that sinters consist essentially of lead silicates, lead-zinc silicate, calcium zinc silicate, and spinel (ferrite). Lead oxide and lead sulfate areas appear to result from insufficient mixing of the materials prior to sintering. The data give an insight into the process and show that sintering results from a complex interaction of all constituents and that sintering is not simply a matter of diluting the mixture to control the oxidation of lead sulfide.

Jan 1, 1975

Efficacy of Enhanced Gravity Separator in Processing Indian Iron Ore Slime The slime sample was subjected to concentration using Falcon concentrator for their enrichment. The effects of three important variables, eg bowl rotation frequency, back water flow rate and per cent solid were studied on the process performance. Increasing the rotation of the Falcon bowl, enable more material to the underflow by increasing the yield, whereas, the iron content decreases steadily with increasing the rotation of the bowl. The increase in the back water flow effectively removes the clay materials from the underflow at the expense of the yield. Similarly, increasing the per cent solid concentration in the feed produces a better product both in terms of yield and Fe content. Results show that EGS/Falcon can be used for processing Indian iron ore slime and producing pellet grade concentrate.

Sep 13, 2010

By A Brzovic, E Córdova

In an underground mine, different mining activities such as undercutting and cave progression generate redistribution in the present in situ stress field, and these changes are represented in the rock mass through induced seismicity.In order to study and analyse the induced seismicity generated in El Teniente, a block model was developed to account for the dissipated seismic energy through different areas of the mine from 1992 to 2015. More than 2.1 million seismic events were unified and classified in 3D in order to be used for the interpolations. The resultant model variables account for the accumulated energy releases in a monthly time resolution, and provide the ability to intersect different 3D entities with the stored information in the blocks, and estimate the energy evolution inside these entities.The generated model was used to analyse the geotechnical variables that determine the seismic response for the rock mass in the mine, such as geometry and direction of advance of the undercut fronts, lithological domains, and to study the ‘work’ the rock mass needed to go through in order to generate caving in areas with different stress settings.A specific area of the mine under high-stress conditions was analysed by studying the seismic energy associated with two subsidence caves interacting around the project, the modelled lithology. Using the same approach two adjacent projects are analysed to understand the released energy from the rock mass based on different stress and geotechnical settings for each project.CITATION:Córdova, E, Brzovic, A and González, R, 2016. Analysis of progressive seismicity and its correlation with geotechnical variables at the El Teniente Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 835–844 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016