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The Rosebery and Hercules mines, situated in the Rosebery-Williamsford district in western Tasmania, have a history of production dating back to 1896-7, although full scale production did not commence until 1936, following the development of a satisfactory process of selective flotation (Hall, Cottle, Rosenhain and McGhie, 1953). The mineral composition of the Rosebery zinc-lead ores was first described in detail by Stillwell (1934). The Hercules ore is generally similar, but as yet no descriptions of it have beenpublished.Since Dr. Stillwell's paper appeared, the management of the Rosebery and Hercules mines has from time to time submitted a number of interesting mineral specimens to C.S.I.R.O. Mineragraphie Investigations. Examination of these specimens brought to light eight minerals, some relatively uncommon, not previously recognized in these ores.They are cassiterite, molybdenite, stannite, electrum, meneghinite, boulangerite, pyrargyrite and pyrrhotite. Some of the specimens are also rich in tetrahedrite and gold. In addition each of the other ore minerals described by Stillwell, viz. pyrite, sphalerite, galena, bournonite, chaleopyrite and arsenopyrite, was detected in one or more of the specimens examined during the present study. The principal gangue minerals were found to be quartz, manganiferous carbonate, sericite and barite, agreeing closely with the observations of Stillwell.The present study was based on the examination of the following eight specimens.

Jan 1, 1960

For the first time in its history, the George A. Fox Conference let its focus venture away from the friendly confines of the East Coast of the United States to spend part of the one-day conference looking at projects from around the globe. With a record-setting attendance of 377 people, the conference, titled ?Tunneling: An international perspective,? opened with a keynote speech from special guest In-Mo Lee, professor, Korea University in Seoul, South Korea. He is also the president of the ITA-AITES. In a sweeping presentation, Lee walked the packed audience through some of the most fascinating and challenging projects in his home country. Among the projects he spoke about were Korea?s longest railway tunnel, the Solahn Tunnel and the Inje Tunnel, a freeway tunnel that is 11.94 km (7.4 miles) long.

Jan 1, 2012

By J. O. Osterberg

The realities of foundation enginering are that the work never proceeds exactly as expected. The various reasons, exploration, design, construction, and legal are discussed. Case histories are presented with an analysis of why the projects did not turn out as expected and how the difficulties might have been avoided.

Jan 1, 2010

By Olli Haavisto, Juha Timperi

"Accurate on-line assays of mineral slurries are the basis for effective operation of flotation circuits. Typically the elemental content measurements are obtained by an X-ray fluorescence (XRF) analyzer, which samples the process lines and performs the analysis concurrently line-by-line. For a more frequent measurement of each slurry line the XRF measurements can be complemented with reflectance spectrum information. In reflectance spectroscopy the absorbance properties of the slurry in the visible and near-infrared wavelength range are analyzed. The advantage of reflectance spectroscopy is that measurements can be obtained quickly and simultaneously from several slurry lines. However, since the shape of the spectrum is only indirectly affected by the slurry elemental contents, frequent calibration of the measurement against the XRF analyzer is necessary. This study elaborates the combination of reflectance spectrum analysis with XRF. Results of laboratory tests for different slurries are presented and the operation of the system in a copper-zinc flotation plant is demonstrated.IntroductionElemental analysis of mineral flotation slurries is the most important factor in evaluating the performance of concentration processes. Timely on-line assays are also used as the basis for controlling the circuits and ensuring that the grade and recovery targets are reached. X-ray fluorescence (XRF) is the dominant technology in on-line elemental slurry analysis, and typically centralized XRF analyzers are used. The advantage of a centralized analyzer is that one measurement probe can be used to acquire the data from several slurry lines. This reduces the overall operating cost of the system when compared to distributed analyzer system design with several measurement probes requiring maintenance and spare parts. Slurry samplers are installed in the interesting process flows and representative sample flows are brought to the analyzer, where the slurry is further sampled and measured consecutively by the XRF analyzer. Due to the centralized structure of the analyzers and consecutively measurement of the sampling lines the sampling interval per slurry line can be relatively long. In larger concentration plants with several sampling lines a typical assay interval is in the range of 10-20 minutes."

Jan 1, 2016

By Richard E. Danell

"There are a variety of approaches for wall control blasting in open pit mining operations. Safety forworking in the pit is the principal benefit. There are also a number of economic and productivitybenefits when appropriate techniques are used. The purpose and requirements of wall control blasting can vary quite significantly for different operations. When considering blast design, geology, geotechnical factors, drilling, explosives, economics and blasting history are all part of the engineering design process. In many operations, there is a high reliance on blasting history and economics for determining wall control blasting measures. This presentation outlines approaches that broaden the design process and discusses their advantages."

Jan 1, 1997

By Prasenjit Basu

Drilled displacement piles are being increasingly used as foundation elements, particularly in projects requiring fast construction. Different types of drilled displacement (DD) piles are available in practice. DD piles are classified according to the drilling tool design and installation method. The capacity of a DD pile, depending on its type, is between the capacities of geometrically similar nondisplacement and full-displacement piles installed in the same soil profile. This paper provides an overview of the different types of DD piles and their installation techniques and describes three design methods used in practice. It also compares DD pile capacities obtained with these design methods for two different sites.

Jan 1, 2010

By Jeffrey Johnson, Carl Sunderman, Ted Williams, Stephen Signer, Douglas Bayer

To measure the loading behavior of friction bolts, researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) installed strain gauges on the interior of friction bolts and developed a battery-powered miniature data acquisition system (MIDAS) that fits inside the hollow portion of the friction bolt. The advantages of this system are that it is protected from face blasts and eliminates the need for external wiring. Laboratory pull-out tests showed that friction bolts installed in a concrete block with resin were loaded to about 1.8 tons/ft of bolt length; bolts installed without resin were loaded to 1.3 tons/ft. Three strain-gauged friction bolts were installed at Hecla Mining Company’s Gold Hunter Mine, Mullan, ID, in the wall or rib of a mechanized cut-and-fill stope. The object of these tests was to establish an installation procedure for the bolt-and-MIDAS combination and to evaluate performance. The stope was advanced in three 15-ft increments and strains induced in the rock bolts by stress changes in the rock were recorded every 30 minutes. The MIDAS proved to be rugged enough to withstand the shock and vibration from nearby (5 ft) face blasting. Data from MIDAS showed that the friction bolt installed with resin was the most sensitive to each face advance. It showed a steady increase in loading to a maximum value of 1000 microstrain. The friction bolt installed without resin showed stick-slip behavior with loads to a maximum of 400 microstrain before the stope was completed.

By Eric Konigsmann

"The Pogo project is located on the Goodpaster River, 38 miles north of Delta Junction in east central Alaska. Sumitomo Metal Mining and Teck Corporation are planning to develop a 2,500 ton per day underground mine and mill at Pogo. A preliminary resource of 5.5 million ounces of gold has been identified in two flat lying lenses. An underground adit has been developed to facilitate underground drilling of the deposit and to provide samples for bench and pilot scale metallurgical testwork.Flowsheet development included the evaluation of several processing options. The final flowsheet selected includes SAGhall mill grinding, gravity concentration with intensive cyanidation and direct electrowinning, sulfide flotation with ultrafine regrinding, and cyanide leaching and CIP gold recovery from the flotation concentrates. Flotation tailings will be filtered for placement in a dry stack storage facility or disposed of as paste backfill underground. All of the CIP tailings will be disposed of underground as paste backfill. A pilot plant was carried out to evaluate the proposed flowsheet described above and to confirm the gravity recovery predictions.Great care was taken in the development of the flowsheet and site layout concepts to mitigate the environmental impact of the proposed operation. An overview of the site water management concepts is presented and the impact of water issues on the process flowsheet is discussed."

Jan 1, 2002

By A. Kapito

The formation of bainite in steel is dependent on the size of the casting, the heat treatment, and the alloying elements. It is difficult to obtain a fully bainitic microstructure in steels during heat treatment because of its close proximity to the martensite (a?) reaction. The ferrite (a) and pearlite reactions in steels are also rapid and shield the bainite reaction. Alloying elements therefore need to be added to separate the bainite reaction. Boron (B) and molybdenum (Mo) are key elements added to bainitic steels because of their ability to retard the a reaction. Other elements used in the production of bainitic steels are silicon (Si), chromium (Cr), manganese (Mn), and titanium (Ti). In this paper we investigate the effect of alloying elements on the bainite reaction through the use of dilatometry. Dilatometry is a technique that determines phase transformations in the steel and through which continuous cooling transformation (CCT) curves can then be developed. Some initial results are presented of an ongoing study on the development of bainitic steels for railway wheel applications.

Jan 1, 2013

By Earl L. H. Sackett

Barite, although not a glamour mineral and probably little known to many of those in the mining business, is produced in the US. in very respectable quantities and is an important factor in the mineral economy of this country. The scope of the various uses of this mineral is perhaps one of the most misunderstood things about it, for it is surprising how many of those with a casual knowledge of the subject speak of its primary utilization in terms of paint pigments and barium chemicals. The life blood of barite utilization, however, is the petroleum industry by virtue of its dependence on this high specific gravity, inert mineral as the weighting material in its drilling fluids. From 80 to 85% of barite usage in the U. S. is accounted for in this manner-in fact, its role in oil well drilling is the only excuse for some of the large-scale barite production facilities which have been developed. Other uses are important and widely varied, but comparatively they are of small scale. They include fine crushed barite of low iron content as a component in glass manufacture, barite as a source material for manufacture of barium chemicals, finely divided barite as a component of some rubbers and ground, bleached barite in pigments. The formerly substantial use of barite in lithopone, however, has declined markedly because of replacement of lithopone by titanium pigments

Jan 5, 1962

(Published by courtesy of the Great Boulder Pty. Gold Mines, Limited)1. INTRODUCTIONThe faults described in the following paper are of a somewhat unusual character, and have presented a serious problem both in the development and mining of many ore-bodies on the Eastern side of the Boulder Belt. They are mentioned only briefly in the literature of the field, but were observed by, both Stillwell (1)t and Gustafson (2), and have been studied by other geologists and operators in various parts of the "Belt." Their effect on the lodes of Hamilton Section, Great Boulder Mine, was described by King (3) in 1937, and, during recent years, they have been encountered in most of the Great Boulder workings extending east of the Boulder Dyke.Although this paper is based mainly on a study of faulting and development problems on the Great Boulder mine, the general conclusions reached may be applicable to the solution of similar faulting problems in other mines throughout the field.In order to arrive at a clear understanding of the somewhat complicated relationships which the east-dipping faults bear to the lode systems it will be necessary to give a brief outline of the salient geological and structural features of the "Belt" before proceeding to describe the faults themselves.2. GENERAL GEOLOGYThe most recent descriptions of the geology of Kalgoorlie are those by Stillwell (1) and Gustafson (2) and the reader is referred to these as representing the basis of current knowledge of the geology of the field.The Boulder Belt is comprised of a central core of altered quartz dolerite which is flanked on either side by fine grained greenstones and lavas, usually referred to as the calc schists. Down the centre of the quartz dolerite mass there is an infolded bed of slate (2, p. 105) which has been intruded in lit par lit fashion by albite porphyry; the composite body of slate and porphyry so formed is known as the "Boulder Dyke." Numerous smaller porphyry dykes intrude both the quartz dolerite and the calc schist; these vary in composition and range from chloritised hornblende porphyrites to albite porphyries.The whole of the rock assemblage has been subjected tG a considerable amount of folding, faulting, shearing and fracturing, the greater part of which took place before the formation of the lodes.

Jan 1, 1941

By Albert H. Fay

The first data compiled by the Bureau of Mines relating to coal- mine accidents in the United States were published in Bulletin 69," in which the total fatalities by years and States were tabulated from 1896 to 1912. Since the publication of Bulletin 69, further research has been conducted, with the result that the bureau is now able to publish for the first time all of the fatal accidents described in the State inspectors' reports by States, causes, and calendar years, from the beginning of inspection service to date. For the anthracite mines of Pennsylvania, there is a continuous record since 1870; the records of the Pennsylvania bituminous mines are continuous from 1877, and, with the exception of one year, the Ohio records are complete from 1874 to date. In fact, the records of all of the States, with few exceptions, are complete; and incomplete data for any year may generally be attributed to the fact that no report was published during that year. The magnitude of the coal-mining industry in the United States is such that too much stress can not be placed on the need of safeguard- ing the three-quarters of a million men employed. Although the figures given herein show an appalling record for past years, they are not published for the purpose of proclaiming the high fatality rate of the past. They are a record of experience covering a period of 45 years, showing causes and results of many accidents in the coal mines of the United States. They represent a diagnosis of the hazard of the mining industry, pointing out the principal physical causes of accidents, and make available a body of uniform facts that will serve as a basis of preventive measures for use in future operations. It is with these great purposes in view that the Bureau of Mines presents the classified data in this report. Classification and study of mine accidents on the basis of number of persons killed is common and very old, but fails to throw enough light upon the problem involved. Many serious accidents in mines have no fatal results, hence in a tabulation of fatalities they are overlooked and the real hazard of the industry is not made clear. An accident does not necessarily include an injury that may result therefrom. Such accidents as the breaking of a hoisting cable, an explosion of powder, gas, or dust, a runaway car or motor are all serious. Although no loss of life results, they should be recorded, investigated, and studied to prevent their repetition. No accurate data for the United States are available showing how far the personal element as related to the miner and his co-worker, the mine foreman, or to the superintendent and others in authority, contributes to accidents. Many accidents are due to inexperience on the part of the miner, his failure to heed orders, a misunderstanding of instructions and last, but not least, carelessness of himself or his fellow worker. A foreman or superintendent may fail to give proper warning regarding the conditions of certain parts of the mine; he may not have inspected certain rooms or entries on the day of a mine accident; the mine may not be properly equipped, or the operator may neglect to comply with the inspector's recommendations. There is, therefore, a personal element on the part of both the operator and the miner that must be considered. Legislation and the enactment of compensation laws will make the operator realize the seriousness of the mine-accident situation, when fatalities and injuries are to be paid for in legal tender of the realm. The miner must be educated and made to realize the dangers he encounters; he must learn that self-preservation and the safety of his fellow workmen should receive his first attention; he should cooperate with his employer, his asso- ciates, and the State mine inspector to the end that the mine hazard may be reduced to a minimum. "Cooperation for safety" should be the watchwords of the operator, miner, State inspectors, and all others in any way interested in the mining industry.

Jan 1, 1916

By Douglas Rudenko

Most engineers, mine operators, or contractors acknowledge the importance of having accurate subsurface information in order to plan a project or solve a problem. Conventional methods of exploring the subsurface such as augering, core borings, or test pits can provide information, but it is often costly and sparse. Geophysical methods offer an alternative to help supplement sparse information~ gathered through conventional exploration techniques.

Jan 1, 1998

By Bassam Kattaa

"Abstract - A heavy mineral survey of beach and dune sands including geochemical analysis for trace elements was undertaken to evaluate the economic potential of the sands and to understand the nature and distribution of the heavy minerals relative to potential source rocks. Results indicate that heavy minerals are generally derived from outcropping volcanic rocks that comprise a proportion of the hinterland in the south part of our survey area. The most abundant minerals are magnetite and pyroxene. The morphologies of the heavy mineral grains are angular to subangular, suggesting that they were transported short distances from the source rocks. Factors controlling heavy mineral distributions include wave and wind action, proximity to provenance, the fluvial drainage network, and longshore currrents.The most economically important mineral is ilmenite. Zircon and rutile concentrations are relatively minor and thus have lower economic potential."

Jan 1, 2002

By Jorge Meza

Uno de los objetivos principales del proyecto de la modernización de la Fundición SPCC es capturar y procesar el gas generado de la reacción exotérmica del proceso de fusión de los sulfuros del concentrado para transformarlo en un subproducto comercial que es el (ácido sulfúrico) H2SO4. En ese sentido, el presente texto señala el manejo de un sistema de control de gases a través de un proceso sofisticado para el enfriamiento, limpieza y manejo de este gas de dióxido de azufre, reduciendo los costos de operación, así como el tiempo de reacción de los equipos involucrados en el manejo y procesamiento de los gases.

Sep 19, 2006

By Russell E. Griffin

Dielectric constants and dissipation factors were measured by the Bureau of Mines for 13 simulated lunar rocks over the 20-to 100-megahertz frequency range by means of the susceptance-variation method. Measurements were made at room temperature and normal atmospheric pressure. Results are presented and some comparison is made with data reported by others. The rocks used include a broad range of physical characteristics and chemical compositions from the large areas of volcanism in Oregon and northern California, and two nonvolcanic types. These rocks make up a suite of rock standards used by a group of laboratories engaged in lunar research. The data presented will add to the basic scientific and engineering knowledge needed to utilize extra-terrestrial mineral resources for support of future space missions.

Jan 1, 1974

By J L. Maule, S J. Mathews, K A. Rodgers

Gold and Silver bearing epithermal veins of the Golden Cross deposit are hosted in Miocene and Pliocene calc-alkaline volcanics occurring 8 km northwest of Waihi at the southern extent of the Coromandel Peninsula, North Island, New Zealand. Veining occurred during a period of hydrothermal activity that began early to late Pliocene, and possibly continued into the Pleistocene.   Field relations and petrographic relationships reveal that multiple generations of FeS2 occur in the Golden Cross region, with FeS2 occurring in all nine rock types recognised at Golden Cross. The variability of FeS2 morphology was investigated by preparation of high purity FeS2 separates, and grain counting. Marcasite is the dominant FeS2 phase at Golden Cross, and along with pyrite is shown to have a systematic habit variation. Pyrite shows a sequence from cubes through octahedra to pyritohedra to dendritic growth. This pyrite sequence conforms to an experimentally determined sequence. The parallel sequence for marcasite at Golden Cross is from tabular through bladed aggregates to euhedral miscellaneous marcasite morphologies. The FeS2 sequences observed are believed to be due to increasing temperature, and perhaps also increasing FeS2-oversaturation and fluid flow.

Jan 1, 1994

By S. Kraemer

Consumption of plastics has been growing in both the U.S. and world markets since the mid-1930s. This growth is due to plastics being used to make new products and as a replacement material for existing products. This paper develops an understanding of the replacement process by looking at the use of plastic, specifically PVC, in the construction pipe industry. History details the growth of the plastics industry and a discussion of the material selection process indicates the advantages and disadvantages of plastic pipe. Analysis shows that the use of plastic, as an alternative material for pipe, is having a significant effect on the cast iron, copper, clay, and steel industries. For the purpose of understanding the replacement process, three example residential systems were examined with a lifecycle cost analysis being performed. PVC was the material of choice in 1988 for all systems. Even though disposal cost was the one area where PVC was not the most cost effective, disposal costs were not sufficient to offset the overall advantage of using PVC on an economic basis. That plastic competes effectively with other materials, in terms of material properties and cost, indicates that further work should be performed to understand the impact plastics have on other material markets.

Jan 1, 1991

By F. Enslin

Heavy metals and sulphates in acid mine drainage (AMD) can beadsorbed onto bentonite clay, leaving clean water and a heavy metal loaded clay precipitate as products. Due to the toxicity of heavy metals, the clay could not be disposed of safely in the past. A method was thus required to remove the heavy metal content from the clay. Acid leaching was proposed to liberate the heavy metals from the loaded clay. Sulphuric, nitric and hydrochloric acid were considered as lixiviants. Loaded clay samples were leached over a range of pH values from 1 to 3.5 to identify an optimum leaching condition. From the results it was found that metals can berecovered from loaded bentonite clay by means of acid leaching and the optimum pH for heavy metal liberation was found to be 2.5, with uranium as an exception, being optimally leached at a pH of 3. This allows for the possibility of selective leaching. Furthermore, X-ray diffraction analyses indicated that the clay structure did not deteriorate significantly during acid leaching, suggesting that the bentonite could be reused. The treatment of AMD with bentonite clay, and subsequent acid leaching of the clay, is a sustainable solution, and current outcomes could possibly lead to industrial implementation of the process during water purifying and metal recovery from waste streams. Keywords: Acid mine drainage, bentonite, heavy metals.

Jan 1, 2010

By Mike Ounpuu

"Locked cycle testing has become more common practice in the last 10 years. Reasons vary from a desire to avoid pilot plant testing, demand for more variability testing within deposits, and perhaps most importantly, a request from the financial institutions who invariably finance many of the projects. Surprisingly, many people don’t understand locked cycle testing, analysis and balancing. This paper provides a brief overview of locked cycle testing, and then progresses into a more detailed discussion on the analysis and balancing of locked cycle test data. The paper endeavors to educate CMP personnel on how to determine if the test was good and if a reasonable metallurgical projection was made. The paper uses case studies to illustrate the key points.INTRODUCTIONA locked cycle test is a repetitive batch used to simulate a continuous circuit. The basic procedure has a complete batch test performed in the first cycle which is then followed by similar batch tests which have “intermediate” material from the previous cycle added to the appropriate location in the current cycle. These batch tests, or cycles, are continued in this iterative manner for an arbitrary number of cycles. The final products from each cycle, i.e. final concentrate and final tailings, are filtered and thus removed from further processing. At the end of the test, all the products, final and intermediate, are dried, weighed and subjected to chemical analysis. The test is balanced and a metallurgical projection is made.This description can be found in many of our classical textbooks for the mineral engineer 1, 2, 3,4. Unfortunately, none of these textbooks provide any discussion beyond the basic procedure. Often, they provide comments such as in Taggart’ where he states; “It is questionable whether in any case it approximates mill results any more closely than the standard batch test”. It is truly surprising that our classic textbooks promote that locked cycle tests are more art than science, and suggest that they can be of dubious value. None of the textbooks provide meaningful insight or discussion in how to assess:"

Jan 1, 2001