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By A. Lyndon

Vertical and lateral load tests were carried out on two 13 m deep bored cast-in-place instrumented piles, socketed into weathered sandstone. The first pile, 1200 mm in diameter, was loaded vertically to a maximum of 16000 kN and then loaded to failure under lateral load (1900 kN). The second pile, 1500 mm in diameter, was tested under lateral load up to a maximum of 2400 kN. It was found that the deflections of the 1200 mm pile were more than twice those of the 1500 mm pile under similar loads. The soils on the site are not easily tested in the laboratory, or by conventional insitu site investigation techniques, parameters needed in design can only be reliably obtained from pile test results. In this report shear moduli are back analysed from the vertical load test and the two lateral load tests. For these similarly installed piles very different design parameters were determined from the lateral load tests, the only known major difference between the piles being that the 1200 mm pile was loaded vertically before it was loaded laterally. Changes in G values needed to match performance under vertical load if applicable to lateral loading could have accounted for a significant amount of the difference.

Jan 1, 1989

By D. J. Bauer

Oxidation of mixed lanthanide solutions with ozone at pH 4.5 and at ambient temperature resulted in precipitation of 98 percent of the original cerium present. Corresponding cerium purity was increased from 50 to 98 percent. A second ozone oxidation-precipitation step produced cerium of 99.9 percent purity in high yield from the 98-percent-pure material. Alternately, ozonation at pH 6.5 and 85° C differentially precipitated cerium and rare-earth elements heavier than cerium and left 89 percent of the original lanthanum in solution at a purity of 95 percent. Subsequent recovery of cerium from the heavier rare-earth elements in the precipitate was accomplished by dissolving the precipitate in dilute mineral acid and reoxidizing the cerium with ozone at pH 4.5 and at ambient temperature. The filtrate contained an enriched praseodymium-neodymium-samarium-europium mixture that is amenable to separation by ion exchange or solvent extraction.

Jan 1, 1968

By Alex C. Smith, Thomas A. Gray, Lynn M. Crayne, Michael A. Trevits, Phil Glogowski

Mine fires constitute one of the greatest threats to the health and safety of those working in the underground environment and each event has the potential for disastrous consequences. Of the major mine fires and thermal events that have occurred in the United States in the last 6 years, it is estimated that remotely installed seals could have been used in 63% of the events to control fire growth or to aid in fire suppression work. The National Institute for Occupational Safety and Health (NIOSH) is conducting full-scale tests at the NIOSH Lake Lynn Experimental Mine to evaluate and improve remote mine seal construction technology. The main focus of this work is to develop reliable technology that will completely close the mine opening from floor-to-roof and rib-to-rib. This paper presents the results of remote seal installations using grout-based materials.

By D R. Cohen

As one of the four basic sciences, the study of geology is intrinsically worthy as a means of increasing fundamental knowledge of the behaviour and evolution of the universe. Geological knowledge can also be translated into practical outcomes for society such as resource discovery and protection of the environment. Australia has a long tradition of providing very high quality geoscience programs to prepare graduates for a range of occupations. We are, however, reaching a nexus in the way universities should or can deliver engaging programs. This has been triggered by the rapid evolution of the digital world (the Internet of Things), new technologies, unprecedented access to information, better understanding of the processes by which we learn and adapt our thinking, growing complexity in the problems we must face or opportunities to grasp, and university funding models. Designing education programs for the next generation of geologists extends far beyond tinkering with syllabuses. We must develop skills sets that will allow graduates to work in rapidly changing landscapes, but in doing so may have to sacrifice content to build capability in our graduates. Whereas universities must respond to changing demands on graduates by ensuring degree programs contain an appropriate balance of material and high quality of delivery, industry and government must also fulfil their responsibilities to provide additional training programs for graduates to assist their rapid transition into independent professionals. This paper examines various educational issues being considered in developing the new Decadal Plan for the Earth Sciences, and reflects on directions that education is heading in many of our universities.CITATION:Cohen, D R, 2017. Educating the next generation of geologists, in Proceedings Tenth International Mining Geology Conference 2017, pp 3–10 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By Jean-Pierre Hamelin

Ground movements induced by underground excavation are always of critical concern, particularly in urban areas. Compensation grouting now appears as a safe means to control these movements. The paper presents new advanced systems developed by the specialist contractor to bring, at all stages of the project, an efficient control of operations and presents a case history taken from the project at Tren Urbano, Rio Piedras Section, constructed beneath an historic commercial section of San Juan de Puerto Rico.

Jan 1, 2000

By Jacques Ouellet, Ferri Hassani

"Within the mining industry paste backfill technology has evolved over the last two decades. This technology aims at producing safe and cost effective backfill of high strength. When used as cemented backfill underground the usual practice in the mining operations was to consider the backfill as a component under the production engineer responsibility. With its growing use in various site conditions some problems were encountered. Over time the mechanical characteristics of paste backfill could deteriorate. Investigations on these problems brought an increased understanding of paste backfill chemistry. Effectively, paste backfill is produced with tailings slurry having sometimes very complex chemistry and mineralogy. The bonding agents can be sensitive to the chemistry of these slurries. Today, a new understanding of the complex chemical reactions involved in cementing paste backfill is derived from concrete research literature. Cemented paste backfill is a manufactured product and as thus all steps involved in its making must be looked at. Both the processing engineers and mining engineers need to be involved. The proposed paper will go over the various developments and new understanding gained over the years on paste backfill chemistry. The authors had the opportunity to work with various Canadian mines that implemented paste backfill in their operations. Chemical alterations case study will serve to illustrate the importance of a good understanding of cement and paste chemistry. The authors will then conclude on research orientations needed to bring a more efficient use of paste backfill technology. The crucial role of the processing engineers in the paste backfill manufacturing will be discussed.INTRODUCTIONPaste backfill is usually prepared from a mixture of solids and water containing at least 15% particles smaller than 20 microns with the addition of binders for mechanical strength. Historically, tailings had been classified to extract the fines and only the coarse part was placed underground as sand slurry. Paste fill was researched in the last three decades to enable mining operations to use all the tailings, including fines, in backfill. The outcome of the early studies showed that paste fill provides high strength but due to preparation complexities and transportation problems is expensive. A greater understanding of the transportation mechanisms and advances in dewatering technology in recent years has resulted in more practical use of paste backfill."

Jan 1, 2002

In late 1989, first-pass reconnaissance exploration delineated a 4km x 6km geochem- ically anomalous area centred 10km WNW of Kainantu in the Eastern Highlands Province at 6¦13'S and 145047'E. The area, named the Basangka prospect, lies between 2 200 and 2 400m asl. Interest in the area was prompted by a 14ppm Au assay of a silica-pyrite breccia float sample taken near Henkai village. The prospect was defined after several acid-leached silica- pyrite breccia and comb textured quartz float samples returned assays above lppm Au and relatively high Ag. Very encouraging and anomalous Au values were obtained from panned concentrates, despite the absence of visible Au colours. Several pan concentrates returned greater than 1mg Au and it is believed that the Au occurs as inclusions within iron oxides which were originally pyrite. In this early stage of prospect exploration, any Au value above 0.lppm in- 150# fraction stream sediments is treated as anomalous. Rock chips, panned concentrates and -150# fraction geochemistry all vividly define the areas of interest at Basangka.

Jan 1, 1991

By Y. Q. Zhang, Y. Luo, S. S. Peng, C. T. Holland

Barrier pillars in underground coal mines could eventually be subjected to a hydraulic pressure head due to the build-up of mine water in the old workings. The pressure head could not only act as a force to destabilize the pillar but also cause seepage flow through the pillar and its surrounding strata. Excessive seepage flow could induce piping failure that in turn could accelerate the mechanical failure process of the barrier pillars. In this paper, finite element simulation approach has been employed in the evaluation of the barrier pillars. Both the stress distribution and the seepage flow pattern in and around a barrier pillar have been simulated numerically. The effects of ground stress on rock permeability to water seepage has been taken into consideration in these simulations.

Jan 1, 2001

By S Yuen, T Rana, S Khan

Many open pit mines require dewatering or need aquifer depressurisation systems to manage mine water inflow and/or mine floor stability. In many instances these mining operations impact on regional groundwater resources and therefore access to these resources by other users.As such potential exists for mine development to be hindered or even blocked by groundwater legislation that aims to prevent declining groundwater levels and demonstrate equitable use of a regional groundwater resource.There is a need to manage aquifer systems during and after the mining operations, and in some cases stresses on the aquifers and associated ecosystems may be elastic and can be managed with minimum impacts or reversed once the mine ceases to operate.This paper uses the Gippsland sedimentary basin, with a history of declining groundwater levels and mining and petroleum production, as a case study to pose the question: Should period of mining operation, aquiferÆs storage capacity and its ability to recharge be concurrently considered when granting groundwater abstraction and mining licenses for prospective mine development?It further examines that by utilising an aquiferÆs storage capacity and demonstrating an understanding of aquifer system hydrodynamics during and beyond the life of the mine (time), the approval process for groundwater abstraction and associated cost of statutory monitoring may be made less onerous.

Jan 1, 2009

By E. L. Singleton

The Bureau of Mines investigated extraction of aluminum from aluminum-silicon alloys as a means of utilizing domestic aluminum silicate ores for aluminum production. Aluminum was extracted from aluminum-silicon alloys by electrolysis in molten electrolytes of NaCl-KCI-AIC13 and NaCl-KCI-AIF3 in a laboratory-scale cell. Six alloys with aluminum contents ranging from 20 to 87 percent aluminum were tested, and aluminum products of primary grade or better were obtained. More than 80 percent of the aluminum was recovered with current efficiencies as high as 91 percent. Recovery of a metallurgical-grade silicon product from the anode residue by an acid leaching procedure was possible with the 50-50 and 65-35 Al-Si alloys.

Jan 1, 1972

By Bruce I. Thomas

Reconnaissance studies of beach sands along the eastern part of the Gulf of Alaska were conducted by the Bureau of Mines to determine if any of these coastal areas warranted investigations as possible sources of valuable minerals. Because of difficult access and limited transportation facilities only a minimum of sampling, surveying, and camping equipment is utilized to obtain spot samples from key areas as well as information indicating the location, size, and character of the deposits. Such data were obtained from beaches located along approximately 247 miles of the Gulf of Alaska coastline during parts of the 1957 and 1958 field seasons. A total of 201 3-inch-diameter auger holes, spaced roughly at 1 mile intervals, were bored by hand methods to depths ranging from 3 feet to 27 feet; also 33 shovel samples were collected from selected localities. Samples were reduced to a rough concentrate in the field by panning; the rough concentrates were shipped to the Bureau of Mines laboratory at Juneau for further concentration and for petrographic and chemical analyses. Particular attention was given to the heavy-mineral content of the concentrates, although the types and relative amounts of rock-forming minerals were also determined. The reconnaissance indicated that, generally, the valuable mineral content of the beach deposits was too low to be of further interest except in the vicinity of Yakutat and Lituya Bays where erratic but possibly significant concentrations of magnetite and/or ilmenite were found. At Yakutat, about 20 miles of beachline extending southeasterly from Ocean Cape, yielded samplas containing from 1 pound to over 300 pounds of iron and from a trace to over 100 pounds of titanium dioxide (TiO2) per cubic yard of beach material. However, the higher grade samples represented local concentrations of minor importance. The general tenor of the Yakutat beach, as indicated by the airthmetical average of 27 auger-hole samples, is about 35 pounds of iron and 20.5 pounds of titanium dioxide per cubic yard of beach material. Ilmenite is the predominant heavy mineral of the beach deposits in the vicinity of Lituya Bay, but it was found in concentrations only in limited areas near the

Jan 1, 1962

In most mines using presplitting the final excavated wall shows a zone of damage just below the crest and well defined presplit half barrels. The crest damage (surface dilation) zone varies and is added to by subsequent adjacent perimeter blasting operations. Keeping the preconditioning to a minimum is possible using the methods described in this paper, developed on several diverse and geographically distant mining operations to control crest dilation and preconditioning by presplitting in advance - not just laterally but vertically in advance. The first documented case (Delbridge, Marton and McSweeney, 2004) in the development of the concept was undertaken at AngloGold Australia Pty Ltd's Sunrise Dam Gold Mine (SDGM), located beside Lake Carey, some 730 km northeast of Perth, Western Australia. The mine had been developed in a series of cutbacks to a depth of over 300 m and began underground mining during the latter stages of open cut operations. This mine is fairly unique in that it utilised a single pass vertical presplit which initially extended over three bench heights and after the failure mechanisms were understood, over four benches. The presplit drilling for the three stacked benches started on the floor of the second bench so that any dilation was confined to the surface one bench above the crest and modified perimeter blasting was then developed to curtail damage from blasting adjacent to the new crest. The second case is based on a South African coal mine in the Witbank Coal Measures, 140 km northeast of Johannesburg, Republic of South Africa (RSA). It was important that blasting for optimal wall stability and minimal scaling was developed in advance. A dragline is scheduled to excavate the #2 seam midburden which is the lowest of the economically viable coal seams in the five seam Witbank Coal Measures. Mining of the overburden, coal and partings above the dragline midburden pass are by excavator and truck and each mining layer is individually blasted. The results of presplitting the midburden through the overlying coal seams and partings have provided a presplit with no surface dilation of the midburden crest and ensures any subsequent crest loss is solely due to blasting adjacent to the vertical presplit. Typical of all coal mines in South Africa only vertical presplits are used. Wall control is most commonly delivered by presplit blasting and one common sight after the dust clears is a ridge of broken blocks along the presplit row, usually with a main crack running between the presplit blastholes and often parallel cracks either side of the perimeter line. The surface rock strata or block structures have been dilated by the venting gases and shock waves. Decoupled, fully coupled, single or double deck charges are used depending on a variety of factors, anecdotal practices and perceived benefits. Preconditioning of the crest rock by blasting from above may not be visible to the naked eye (or non-existent in overburden in strip coal mines) but the high speed venting of explosives gases (and often the water in the presplits) preferentially follow existing cracks and structures because there is no developed presplit crack near the surface. This nearly always lifts, shifts and separates the surface structures and geological layers. Stopping the dilation by 'sacrificial' or 'in advance' presplitting has been shown to reduce the crest loss at both metal and coal mines. Drilling and presplit blasting through an upper level of bench or layer provides a degree of restraint to the target layer where the crest must be maintained and any damage caused by the venting gases will not cause concern as it is removed as planned, leaving a stable crest.

May 1, 2010

By G. P. Houston

This is the final, report submitted for the Contract No. H0220002 with the U. S. Bureau of Mines for the design and development of a Permissible Automatic Data Acquisition System (PADAS) to measure and record roof stresses in underground mines Basically the PADAS is a portable, battery powered, 24-channel data acquisition system designed for safe unattended operation of up to 30 days duration in explosive environments. The unit will accommodate twenty-four pressure transducers or eight borehole deformation gages (or any combination) at distances up to 300 feet from the PADAS to measure pressures up to 10, 000 psig. All 24 channels as a selected group are scanned sequentially at one of several selectable rates.

Jan 1, 1973

By Clarke E. Schuetze

This project had as its objective the experimental investigation of water capsule production utilizing the Southwest Research Institute's submerged nozzle encapsulation apparatus (U.S. Patent 3,389,194). Initial efforts on this project involved nozzle configuration and shell formulation optimization. The shell formulation developed on a prior program was modified during the course of the project to obtain the best balance of capsule breakage resistance and water retention. Subsequent effort centered on determining operating conditions which would produce the best quality capsules for each candidate shell formulation as determined by laboratory tests. Some preliminary work was done to increase the production capacity of the encapsulation equipment. The program was extended with major emphasis concerned with scale-up studies of capsule production capacity and the treatment of problems associated with grouting cartridge fabrication. During the course of the program, water-containing capsules were produced which have good long-term water retention, block resistance and adequate strength. Using a single-nozzle design, a production capacity of 15.9kg (35 pounds) per hour was demonstrated to give acceptable capsules based on initial results.

Jan 1, 1978

By M. A. Schellhardt

In recent years development of instruments and equipment for determining subsurface pressures and temperatures in. gas and oil wells has made it feasible to obtain information that eras not available in the past on many gas-production problems. The material presented in this report illustrates particularly the value of subsurface-temperature data in the study of subsurface leakage from gas wells. An abnormal decline in the shut-in pressure of the Lone Star Gasoline Co. A. Jones No. 1 gas well in the southern part of the Buffalo (Tex.) field was observed during an interval when a negligible volume of gas bras being withdrawn from the reservoir. Wellhead-pressure readings indicated that the shut-in pressure of the well declined from 2,295 pounds per square inch gage on February 3, 1937, to 1,445 on February 12, 1935. Tests conducted by engineers of the Lone Star Gas Co. suggested that the subnormal pressure gaged on February 12, 1938, probably was not caused by a head of liquid in the well.

Jan 1, 1940

By Mark S. Sanders

Six underground coal mine shuttle cars (three high seam and three low seam) were used to assess visibility using the concept of visual attention locations (VALs) and an improved human eye reference measurement instrument (HERMI Mark II). Each machine was assessed in the inby and outby direction of travel with no canopy and with the canopy in its highest, and lowest position. In addition, the illumination level at each VAL was determined. Results showed that the most important variable determining visibility was operator eye position. When this variable is controlled, the addition of a canopy has no effect on visibility. Further, with eye position controlled, there is no difference in visibility between high and low seam machines. The visibility and illumination assessments found blind spots in the operator's field of view located on the opposite side of the car from the operator and ahead of the machine. Suggestions for reducing the blind spots were made. The report also included a procedure manual for using HERMI and the system of VALs to assess visibility from underground shuttle cars, continuous miners, and scoops.

Jan 1, 1983

By Wolfgang G. Brunner

The closing of the gap in the European waterway- net is one of the big and challenging traffic projects following the German reunification. The water canals in the North German plain connect the Rhine river, the border between Germany and France, with the Oder, the German border river to Poland. As early as in the 30's of the 19th century the planning and construction of a ship- lift and a canal bridge started, in order to close this last big gap in the system between the Mittelland Canal and the Elbe- Havel Canal near Magdeburg. This main waterway connects the West of Germany, known for its coal mines and steel mills, with the capital Berlin, and from there it goes on into Poland. The building activities started in 1934 but came to a complete stop in 1942 because of the war. The communist government in East Germany was not interested in continuing this huge project, including the ship lock Rothensee, the canal bridge crossing the river Elbe, the former border river between West and East Germany, and the lock Hohenwarthe due to lack of political backing along with low construction capacity. Now this important project is in progress and this report describes the special foundation techniques used on the great ship lock Hohenwarthe. Hohenwarthe is a double- bay ship lock of considerable scale, which is notable for recirculating water rather than letting it flow. It includes 44 800 m2 ( 481 720 sq. ft) of up to 55 m ( 180 ft) deep cut- off walls, ground water control, 1248 bored piles with a depth of 22 m ( 72 ft ) serving as foundation and 28 000 m ( 91 864 ft) of soil densification with vibroflotation equipment for ground improvement. In the year 2003 the project shall be completed and all ships can travel from the West to the East through Germany without expensive and time- consuming detours through other canals and locks.

Jan 1, 2000

By Walter D. Holland

This is one of a series of instruction guides developed to help instructors present health and safety training courses to workers in the metal and nonmetal mining industry. This course is intended for training those, usually the safety officers, who perform surveys for inhalation contaminants in above ground work areas. The handbook entitled ?Handbook for Surveys of Inhalation Contaminants in Above Ground Metal and Nonmetal Mining and Processing Work Areas? is used as a manual for the course and as a prime reference when performing the actual surveys or interpreting the sampling results. There are six experiments for the students to perform during the course to familiarize them with the sampling devices routinely used during the surveys.

Jan 1, 2011

By J. Roth

The purpose of the present study is to increase the safety of explosive storage. This was accomplished by: a) review of the histories of recent and past magazine explosions to define causes and trends; b) observation of present-day explosive storage conditions and practices at active mines; c) examination of existing Federal regulations on explosive storage to determine whether they address all conceivable safety problems, whether they contain redundant or obsolete standards, and whether their intent is clearly stated; d) recommendation, for safety improvements and for revision and clarification (if necessity) of governmental regulations. Magazine explosions are rare. A recent increase in magazine explosion frequency must be attributed to a large increase in deliberate (criminal or malicious mischief) explosions. Fires of various origins account for the remaining explosions of the past decade. During 1884-1926 several lightning-generated explosions occurred in non-metal magazines, but none recently. It appears that the contents of a well-constructed, metal magazine are immune to direct lightning strikes, regardless of whether the magazine is grounded or not grounded. Grounding a metal magazine cannot be harmful, but it may well be superfluous. Magazines were observed at 34 widely separated mines and storage problems were discussed with personnel at these mines. In general, storage conditions and practices were found to be satisfactory. Usually, only small quantities of explosives are stored on mine property since most explosives are brought in by suppliers when needed. MSHA and BATF standards on explosive storage appear to cover safety aspects adequately. However, certain revisions are recommended to clarify some of these standards and to reduce inconsistencies in their enforcement.

Jan 1, 1983

By Louis Schaffer

The objectives of the research were to determine whether a model health and safety program could be defined in terms which would enable its application to mines of all types, and, if such a model program could be defined, to determine through evaluations in two mining companies whether it would achieve measurable improvements. Volume 1 describes the model, how it was applied in the field and how it was evaluated. This, Volume 2, describes the literature and field research that preceded the model definition.

Jan 1, 1983