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By C. E. Hennig

On January 1, 1961 there were 311 petroleum refineries in the United States with a total crude-oil throughput capacity of slightly more than 10 million barrels per day, according to the Bureau of Mines' annual survey. Compared with a year ago, this represents net increases of one in the number of plants and 109 thousand barrels per day in total capacity. Contributing to this increase was the completion of two new plants, one in Hawaii and another in Michigan, during the year. At the beginning of 1961 the industry was building facilities which will increase this overall crude capacity by 36,500 barrels per day. As part of its building program, it was also replacing 329,000 barrels per day of its present capacity. Of the total 10 million barrel per day installed capacity, the industry reported 380,000 barrels per day as being shut-down on January 1, 1961. This included 11,500 barrels per day considered inoperable without extensive reconditioning.

Jan 1, 1961

By Alessandra Savazzini dos Reis

A crescente preocupação em relação às áreas de proteção ambiental e ao alto consumo de argila, matéria-prima da cerâmica vermelha, ocasiona a indisponibilização progressiva de reservas de argilas no Brasil. Com isso, vê-se a necessidade de incorporar resíduos na massa argilosa para confecção de produtos de cerâmica vermelha. A indústria de cerâmica vermelha brasileira consome cerca de 10 milhões de toneladas de argila ao mês para produção de telhas e blocos. Na própria olaria são gerados resíduos, tal como, o resíduo de massa cerâmica crua originado na etapa de conformação das peças. Este trabalho visa incorporar o resíduo de massa cerâmica crua na massa argilosa usada em cerâmica vermelha. O resíduo foi caracterizado por meio de ensaios de FRX, DRX, limites de Atterberg e distribuição de tamanho de partículas. Corpos de prova feitos com massa argilosa e resíduo em teores variando de 10% a 90% (massa) foram conformados, secos à 110ºC, queimados à 900ºC em forno industrial e submetidos a ensaios de absorção de água, porosidade aparente, massa específica aparente e resistência à compressão. Os resultados evidenciaram que as propriedades cerâmicas avaliadas nos corpos de prova da massa argilosa incorporada com o resíduo atendem aos valores das argilas-padrão brasileiras para cerâmica vermelha.

Aug 17, 2017

By Y. P. Chugh

This is the final report of a study done by IIT Research Institute for the Bureau of Mines to identify the problem areas and technological inadequacies in noncoal (metal, nonmetal, stone, and sand and gravel) mining and processing systems that are the primary causes of death, injury and occupational disease, and to make recommendations to improve safety and health in these operations. The findings and recommendations presented in the report are based on: (1) analyses of MESA injury and employment data for the period 1961-70, MESA fatality reports for underground noncoal mines (1968-72) and lost time accident data for 1970-72 obtained from mining and processing operation: (2) visits to a variety of noncoa1 mines and mills throughout the country to observe the operations and to study the safety organization and practices used in the industry and (3) interviews with industry and government representatives knowledgeable in the field of noncoa1 mining and processing safety and health. The report provides a comprehensive overview of safety and health problems.

Jan 1, 1974

By Keith Pucalik

Understanding Vibrations fr om Blasting focuses on explaining blast vibrations and their effects on people and homes while keeping an eye on the importance of the use and significance of explosives in our daily lives. Unlike many predecessors, this film will help blasting pro f e s s i o nals explain blast vibrations and address many of the layman’s most fre q u e n t l y asked questions. The film can be used in pubic hearings, given to homeowners during preblast surveys, or played at educational seminars for professionals. The film can also be used after blasting has begun and residents have already experienced vibration events.

Jan 1, 2004

By R H. Sillitoe

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Geological concepts are employed routinely in porphyry copper exploration at the area selection, prospect appraisal and deposit definition stages. Regional, district-scale, deposit-scale and laboratory-based concepts can all play a role, with the resulting porphyry copper models providing templates for the integration of geochemical and geophysical responses and interpretations. Of the 19 concepts and parameters selected for brief discussion, those relating to subdivision of porphyry intrusions, understanding of diverse and commonly complex alteration-mineralisation patterns and lithocap characterisation are undoubtedly the most influential in exploration. Several of them are of particular importance because of their role in promoting grade development. Additional belt-, district- and deposit-scale features are currently little used but hold promise, whereas others have less practical value but help in underpinning the evolving porphyry copper genetic model.CITATION:Sillitoe, R H, 2015. Recent advances in porphyry copper geology and their exploration utility , in Proceedings PACRIM 2015 Congress, pp 35–44 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By P Mitchell, J Proffett, I Munajat

Batu Hijau is an island arc porphyry copper-gold deposit located in the southwest corner of Sumbawa Island in the Sunda-Banda archipelago of Indonesia. Southwest Sumbawa Island is underlain by Early Tertiary, low-K calc-alkaline to weakly alkaline volcanic and intrusive rocks. Within the mine area the oldest exposed rocks are medium- to thick-bedded, medium to coarse andesite volcanic lithic breccia, thin bedded, fine-grained volcaniclastic sandstones and mudstones and hypabyssal porphyritic andesite. In the eastern portion of the mine area there is a thick sequence of quartz diorite that postdates the andesites. A small stock of Equigranualar Quartz Diorite predates the Batu Hijau deposit and occupies the contact between the andesitic volcaniclastic sequence of rocks and the Porphyritic Quartz Diorite. Batu Hijau is a world-class copper-gold deposit that has a drill indicated mineable reserve of 914 million metric tonnes grading 0.525 per cent copper (10.58 billion pounds copper) and 0.403 g/t gold (11.8 million ounces gold). Mineralised material not in reserve accounts for an additional 580 million metric tonnes at 0.328 per cent Cu (4.19 billion pounds copper) and 0.171 g Au/T (3.19 million ounces gold), and including an oxide copper resource of 57 million tonnes at 0.37 per cent Cu and 0.12 g Au/T. Copper and gold mineralisation is directly related to quartz veining and wall rock alteration that developed with multiple tonalite porphyry intrusions. The tonalites were emplaced along the contact between the andesitic volcaniclastic rocks and quartz diorite intrusives. Copper and gold are zoned around the porphyry intrusions, which are designated by their contact-age relationships and other features as Old Tonalite, Intermediate Tonalite(s), and Young Tonalite(s). The Old Tonalite was the first copper-bearing intrusion, and although it is the smallest intrusion it has the highest quartz vein density, the strongest alteration and the highest grade. At least two tonalite porphyry intrusions followed the emplacement of the Old Tonalite. Each of these intrusions was associated with less quartz veining, weaker hydrothermal alteration and lower grade copper and gold than the previous intrusion. The intrusive cycle culminated with the emplacement of the Young Tonalite, which contains relatively few quartz veins, is weakly altered and mineralised. Hypogene hydrothermal alteration and sulphide mineralisation developed in five temporally and spatially overlapping stages. These stages consist of Early, Transitional, Late, Very Late, and I Zeolite alteration. Early alteration and sulphide mineralisation accompanied each tonalite porphyry intrusion, but with diminished intensity in each subsequent intrusion. Transitional and later stages of alteration and mineralisation postdate the tonalite porphyries and overprint Early stage alteration and mineralisation. Early alteration and mineralisation consisted of biotisation, secondary magnetite and plagioclase development, fine porphyry-style stockwork veining and ore mineralisation. Magnetite-biotite????quartz stringers and dark micaceous (biotite-sericite) veinlets were developed. The veinlets were accompanied by biotisation of magmatic mafic minerals and groundmass. Thin, irregular and discontinuous æAÆ type quartz veinlets and fine-grained chalcocite, digenite and bornite mineralisation accompanies the Early alteration. It is hypothesized that most of the copper mineralisation was originally deposited as bornite, digenite and chalcocite. Secondary plagioclase was added along the selvages of the early quartz veinlets. Early alteration is pervasive within and proximal to the tonalite porphyries. In the distal portions of the deposit, andalusite and anthophyllite formed at intermediate to shallow depths, and in the deeper portions of the deposit, respectively. The andalusite and anthophyllite probably developed at the same time as the early magnetite-biotite-quartz alteration in the core of the deposit. Transitional-age alteration consists of oligioclase/albite-sericite-chlorite- quartz-¦vermiculite and is associated with æBÆ quartz veins. Through-going planar æBÆ veins are thicker than æAÆ and æA-familyÆ veinlets and have chalcopyrite????bornite along vuggy centrelines and narrow oligioclase????albite alteration envelopes. Rare æCÆ chalcopyite¦quartz veinlets were also formed during Transitional alteration. During Transitional alteration early copper sulphide minerals (chalcocite, digenite and bornite) are converted to bornite and chalcopyrite. The majority of the copper (50 - 70 per cent) in the deposit is contained in ores in which chalcopyrite is the predominant sulphide. Late alteration consists of feldspar destruction and replacement by sericite and other minerals. The late alteration is accompanied by the development of æDÆ sulphide veinlets and veins. These veins consist of pyrite and quartz????chalcopyrite. Within the halos of the late pyritic veinlets biotite is replaced by sericite, quartz-sericite, quartz-andalusite, or quartz-pyrophyllite+kaolinite replace plagioclase, and magnetite is converted to specularite and/or pyrite. In the periphery of the deposit, the feldspar destructive alteration, together with outer zones of Transitional-age alteration, constitutes what is commonly referred to as a æpropylitic zoneÆ. Very Late hydrothermal alteration is also characterised by feldspar destruction, but differs from Late alteration in that feldspar is replaced by smectite in association with sericite and chlorite. Sulphide mineralisation in this stage consists of sphalerite, galena, tennantite, pyrite and chalcopyrite. The last stage or I Zeolite alteration consists of low-temperature, open space filling consisting of stilbite or laumontite¦calcite. Supergene oxidisation of the orebody extends to a maximum depth of 210m. Isolated deep oxidation occurs along open fracture zones to depths of ~400 metres along æDÆ vein filled fracture zones. Weak supergene copper enrichment occurs in a thin horizon (15 to 60 m thick) that blankets the top of the deposit. The main supergene copper mineral is secondary æsootyÆ chalcocite replacement of sulphide grains and as veins.

Jan 1, 1999

By D. C. Dahlin, W. K. O’Connor, G. E. Rush, C. A. Summers, S. J. Gerdemann

The Albany Research Center (ARC) conducted studies of mechanical activation by conventional and ultra-fine grinding techniques to enhance olivine reactivity in mineral carbonation reactions. Activated olivine is one of several solid feed materials used at ARC in reactions with carbon dioxide to form carbonate minerals. This paper compares grinding techniques via energy demand data and product characteristics, including particle size distributions, surface areas, full width at half maximum (FWHM) XRD analyses, and particle morphology by SEM analyses. Reactivity was gauged by percent conversion to carbonate in subsequent carbonation tests.

Jan 1, 2004

By P. Huang, D. W. Fuerstenau

Various factors that control the natural flotability of talc, including differences due to crystal face and edge effects, were delineated. For study of talc depression phenomena, dextrin was used as a model depressant. For the enhancement of talc flotation, dodecylammonium acetate (DDAA) was used as the collector. The interaction of DDAA with talc was assessed by flotation experiments and electrokinetic (zeta potential) measurements, from which the role of hydrophobic bonding can be demonstrated. The results presented in this paper provide useful information on how the crystal chemistry and surface chemistry control the electrical double layer, adsorption phenomena, wettability, and flotation behavior of talc in aqueous media.

Jan 1, 2003

By F Battaglia-Brunet, D. H. Morin, Foucher S. ’

In the mineral-processing field, bioleaching of metal sulphide concentrates is currently operated in very large mechanically agitated tanks. Such bioreactors have considerable requirements in terms of power consumption for mixing, aeration and heat transfer. The use of slurry bubble column, where the particles are suspended by gas motion as well as by liquid upward flow, could be an alternative to achieve bioleaching in more economical conditions. In order to compare these two techniques, a unit of stirred reactors in cascade and a bubble column were comparatively operated at laboratory scale in the bioleaching of a pyrite concentrate. For both pieces of equipment, experiments were performed not only in batch mode but also in continuous conditions.

Jan 1, 2003

By Carl Johnson, D. R. Todd

The Blue Ridge Low Level Outlet (LLO) was a design/build contract to provide a secondary means of discharging water from the Blue Ridge Reservoir. The project involved driving a 3.25 m (11 ft) modified horseshoe tunnel by 293.5 m (963 ft) long utilizing conventional drill and blast methodology. The intake shaft and structure were constructed inside of a sheet pile cofferdam surrounded by a maximum of 20.1 m (66 ft) of water. The shaft was excavated 4.87 m(16 ft) diameter to a depth of 12.8 m (42 ft) below the tremie slab elevation. Steel lining, including a transition from 3.66 m to 2.74 m (12 to 9 ft) diameter and a90 degree elbow were installed in the inlet shaft and then backfilled with concrete. This paper will describe the RFP phase, the design phase, challenges of the underground construction and contractual challenges.

Jan 1, 2005

By Jeremy Bosman, Niel Lourens

"Cyclones are used in four main applications in primary wet heavy mineral processing plants i.e. upfront desliming, densifying, and concentrate stacking and tails deposition.UPFRONT DESLIMINGMany heavy mineral ore bodies are associated with high slimes varying from 15 to 60%. The increased viscosities arising from the slimes impact negatively on heavy mineral recovery in the spiral plant. Recoveries can be reduced by up to 10%. Cyclones have proven to be able to remove slime efficiently with acceptable loss of valuable heavy mineral in the overflow. For low slime applications, typically below 25%, it is possible to achieve the desired results using a single stage of cyclones, whilst for higher slimes, two stages of cyclones are required. The overflow of the primary stage is retreated through a second stage to minimize heavy mineral loss."

Jan 1, 2003

One of the most important goals of the experiments is to determine deformation and strength of the rock specimen under applying triaxial load, the status of failure condition is one of the subjects which can be used in soil mechanic and foundation engineering applications. To investigate the effect of confining pressure on the triaxial test, the rock has been considered as bonded-particles method and has been simulated by particle flow code three dimensions (PFC3D). This model, does not have pre-existing microcracks and all the particles have the same size (2 mm diameter), equal to the real specimen shape. To compare the mechanical behavior and failure pattern of the numerical and experimental results at uniaxial and triaxial tests at the same conditions, the Young's modulus, Possion's ratio as well as maximum axial stress have been considered. On the other hand, the microcracks growth and change of failure pattern at the modelling of the uniaxial and triaxial tests with different confining pressures up to failure point were reported. According to the experimental work, the number density of microcracks decreases from starting value and remains almost constant up to the failure beyond that point. The comparison of the numerical and experimental results of maximum axial stress and the Possion's ratio revealed good accordance. The initial number density of microcracks at the model was zero and increased while microcracking. Also, the sudden increment around the maximum stress was observed which is because of unstable growing of microcracks near the maximum stress. In all uniaxial and triaxial tests with different confining stresses, the number density of microcracks during the failure remains almost constant which can be considered as a proof of failure occurring in the model. The experimental results indicate the similar trend as well.

Nov 25, 2010

By A. V. Nozhkina

"Transformation of diamond into graphite was investigated in the region of diamond metastability under the action of media chemically active relative to carbon in the temperature range from 770 K up to 2200 K and pressure range from 10-3 Pa up to 3 GPa/IV VIII group metals of periodic system and oxygen were used as media chemically active relative to diamond.Methods of electron diffraction, chemical analyses, emission spectroscopy and X-ray phase analyses were used for determination of the reaction products.It was found that in the region of diamond metastability the stage of catalytic phase transformation of diamond into graphite took place during the interaction between diamond and metal. Metal reduce activation energy for transition of diamond into graphite from 109,4 kcal/mole to 77,4 kcal/mole.Kinetic of phase transformation of diamond into graphite was investigated.Pressure does not considerably influence on the rate of phase transformation of diamond into graphite in the presence of transition metals."

Jan 1, 2003

By Michael S. Moats, Scott C. Campin, J. Brent Hiskey

"Electrochemical techniques are a valuable means of analyzing the passivation of commercial copper anodes. Electrochemical impedance spectroscopy (EIS) provides information concerning transport and reaction phenomena occurring at an electrode surface. Commercial. copper anodes of varying compositions have been examined using EIS. Experiments were conducted in a flat cell with an electrolyte of 40 gil Cu2 + and 160 gil H2S04 maintained at 65 DC. Impedance spectra were obtained at the potentials characteristic of the open circuit voltage and passive region for each anode. The spectra of the passivating films exhibited a flattened resistive/capacitive loop at middle to high frequencies and an inductive loop at low frequencies. An equivalent· circuit utilizing an inductor-resistor series in parallel with the double layer capacitance and charge transfer resistance was adequate in modeling the impedance data. The influence of anodes impurities on the components of the equivalent circuit is discussed and correlated with a hi-layer passivation model.IntroductionPassivation of copper anodes during industrial electrorefining has received considerable attention in the past few decades. Great strides have been made in understanding the roles of anode impurities [1-25], electrolysis parameters [20,26], and electrolyte chemistries [20,26]. Even so, passivation still occurs even in the most modem of refineries. The exact cause of passivation is not fully understood. It is known that the anode surface becomes covered by a passivating film. This film has been proposed to be CuS04'&5H20, Cu20, or mixed oxides. The localized concentrations of Ft, Cu+, and Cu2+ ions determines which phase is more favorable. The presence of these ions is controlled by the reaction kinetics and diffusion of species through the slimes layer.Reaction kinetics between Cu, Cu +, and Cu2+ are based on the dissolution mechanism of copper. There exists four different models to describe the dissolution of pure copper. The classical model of Mattsson and Bockris [27] involves two single electron transfers with the cuprous-cupric reaction being the rate detennining step. More recently, Wong, Collier, and MacFarlane [28] used ac impedance to elucidate a more complex mechanism involving the affect of pH and anions. Their findings indicate that the formation of cuprous ions in solution, Cu(I)so~ is favored over Cu(1I) ions adsorbed to the electrode surface in the presence of sulfate and as pH increases from pH 1 to pH 5."

Jan 1, 1997

By Peter Swanson, John Rettkowski

As part of a research program to reduce injuries and fatalities in the U.S. mining workforce, NIOSH is investigating the potential use of noncontact vibration measurements to identify hazardous ground fall conditions. In the present study, the effectiveness of remote vibration sources in exciting resonant responses in damaged structures is examined. Initial experiments were performed on a damaged concrete slab in a controlled environment. Vibration response was measured with a laser Doppler vibrometer using both single-point and two-dimensional array recordings. Excitation sources included direct mechanical impacts to remote portions of the slab and a remotely located industrial demolition hammer. Surficial damage was effectively delineated with both sources through visualization of vibration response in spectral bands selected to discriminate wave propagation from large-scale slab resonance effects.

By Edward M. Dowey

The concrete lining for a long 8.05 km (5 mi) section of New York City Water Tunnel No. 3 was cast in place. The contractor, Grow-Perini-Skanska, placed over76,841 m3 (100,505 cy) of concrete, pouring 24 hours per day, 5 days per week. The concrete was dropped 204 m (670 ft) to the tunnel level, transported by rail to a concrete remixer and pump, and placed in 146.3m (480 ft) of full circle forms. Some of the many challenges include the sheer magnitude of the job, navigating through drifts, a raise and curves, dealing with ground water inflows, and placing the concrete within time limits.

Jan 1, 2001

By Chelsea Woodward

The Spokane Research Laboratory of the National Institute for Occupational Safety and Health has demonstrated a prototype hydrogen-fueled mining vehicle as an alternative to diesel equipment in underground mines. Safety and control systems were added to allow a 70-kW rubber-tired hydrogen vehicle, originally developed by the U. S. Bureau of Mines and Hydrogen Consultants, Inc. (now Hydrogen Components, Inc., of Littleton, CO), to be tested. This work began in late 2000 and culminated with a Mine Safety and Health Administration fire safety review and field tests at the Stillwater Mine in Nye, MT, in 2004.

Jan 1, 2006

The introduction and subsequent ascendancy of autogenous and semi-autogenous milling for comminution circuits has undoubtedly lead to many economic advantages. From a process viewpoint, however, at least one downside has been the sensitivity of these machines to process input variations. Foremost among these is ore competence, though feed size comes a close second. This sensitivity is due to the reliance of ag/sag mills on the feed ore for their grinding media competence and size. Autogenous (ag) mills are the most sensitive in this respect with semi-autogenous (sag) mills being increasingly less so as the ball charge is increased. Increasingly designers and operators are recognising the importance of feed size and the benefits of manipulating it to improve performance. This has been achieved by installing additional crushing/screening capacity ahead of the ag/sag, better operation of the primary crusher, better control of segregation cased by stockpiles and bins and by changing blast design/practices to modify the ROM size distribution. This paper describes the influence of feed size distribution on ag/sag mill performance with reference to a range of plant data. It particularly concentrates on how changing blasting practice to modify ag/sag feed size can have a considerable overall benefit.

Jan 1, 2003

By P González, E Córdova, E Faundez

An integrated mine system must be capable of displaying and reporting valuable information that can be used to easily understand, manage and take action on the key parameters being reported.One of the key aspects of integration is the standardisation of the mine information up to a level capable of adapting the main characteristics of past projects at the mine and enforcing the same or higher standards for newer projects being developed.At the El Teniente mine, photogrammetry is used to map the advance of horizontal developments, and the constructed 3D representation of each face is then used by the geologists to obtain structural information about the areas being photographed.The mine realised that valuable mining information could also be extracted from the photogrammetry being applied, with three possible areas of development envisioned.The first area was creating a link between the developments being planned on a yearly and monthly basis and matching them with plan sections of the 3D developments of the system to account for any deviations.The second area was to use vertical sections of the 3D developments to estimate the overbreak of the excavations in different areas of the mine.The third area was the provision of a more detailed analysis of the sections so that they could provide information on the thickness of the shotcrete being applied.This paper presents the different alternatives being used and examines how the project is currently being developed and managed at the mine. It also looks at the challenges associated with implementing the reporting platform and the results being obtained.CITATION:Córdova, E, Benado, D, González, P and Faundez, E, 2016. Mine planning information from photogrammetry sources at the El Teniente Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 653–658 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By D. D. Southworth

In 1981, 1982, and 1983, the Bureau of Mines examined the potential for lode deposits of platinum-group metals (PGM) in the Goodnews Bay ultramafic complex, Alaska. The complex consists of the Red Mountain, Suzie Mountain, and Smalls River ultramafic bodies and displays concentric zoning of rock types similar to complexes in southeast Alaska, British Columbia, and the Ural Mountains in the U.S.S.R. Results of the study indicate that platinum is preferentially associated with chromite and magnetite in the dunite core of the complex, and palladium is preferentidlly associated with sulfide minerals in the outer clinopyroxene-rich zones. the most promising targets for PGM lode deposits are the chromite-rich dunite at the heads of Fox Gulch and Squirrel Creek and iron-nickel and iron copper sulfide-bearing magnetite clinopyroxenite and hornblende-rich rocks outward of the dunite core, also in the Fox Gulch-Squirrel Creek area. Significant placer reserves are present in the unmined, deeply buried placer ground in the lower Salmon River Valley, and also in tailings from previous dredging.

Jan 1, 2011