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By R. L. Mazza

This final report on methods of reducing and controlling methane in coal mine gob areas indicates that vertical degas holes are beneficial to the mines of northern West Virginia working the Pittsburgh Coal. The USBM funded project involved the drilling and testing of eight vertical holes (four over longwall panels and four over room and pillar panels) based on a review of 13 previously in existence. Areas of observation included gas production history, flow entry profile, underground methane reductions, strata separations, and casing loads (accompanying subsidence). Observations led to the drilling of successful holes drilled short of the mine. Eleven gas production response to applied vacuum tests were conducted at nine degas holes under the contract. Significant production responses were recorded over longwall gobs.

Jan 1, 1977

Flotation of Smithsonite by Using Siloxane Cationic Surfactants as Collectors

Sep 13, 2010

By Jon G. Bredeson

The electromagnetic noise that exists in a mining environment is quite severe and was shown to have been reasonably well documented by a number of researchers in the Phase I Report. The noise levels are such that prudent communication design requires the careful use of all the electromagnetic noise data available. A comprehensive survey was undertaken to determine techniques used in various industrial environments to achieve secure communications in the presence of electromagnetic interference. The techniques were given in the Phase I Report and are rudimentary, but have produced reasonably good results. A number of these techniques could be applied to the mining environment.

Jan 1, 1980

By S Arai

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Podiform chromitites are commonly found in the Moho transition zone to the mantle section of ophiolites, but have been very rarely found from the current ocean floor, even though some ophiolites are considered as a slice of oceanic lithosphere. One of the factors controlling podiform chromitite formation is the chemistry of host mantle peridotite; an intermediately refractory harzburgite is the optimum host for chromitites. This harzburgite represents the most common lithology of the oceanic lithosphere, where the peridotite-melt reaction, which is another condition, is possibly common there. The oceanic lithosphere mantle is thus a good host for podiform chromitites. The apparent rarity of documented oceanic chromitites is solely due to under-sampling of mantle materials from the fast-spreading ridge and the segment centre of slow-spreading ridges. Some ophiolitic chromitites formed not from genuine mid-ocean-ridge basalt (MORB) but from wet MORB due to the situation of typical ophiolites, which formed not at ordinary mid-ocean ridges but at supra-subduction zone spreading centres.CITATION:Arai, S, 2015. Podiform chromitites do form beneath mid-ocean ridges , in Proceedings PACRIM 2015 Congress, pp 465–468 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

THE Synthetic Liquid Fuels Act (30 U.S.C., 321-325, and amendments) become law April 5, 1644, and a period of intensive research and development in this field was begun by the Bureau of Mines. As part of this program bulletins were published on a pressure hydrogenation,3 the Fischer-Tropsch synthesis,4 and oil shale.5 The Bureau also has published a short bibliography on coal gasification,6 mostly of a theoretical nature. Because coal gasification is prerequisite to Hither the Fischer-Tropsch or coal-hydrogenation processes, publishing this sizable, collection of technical information in this form will be valuable. The material is presented in three parts, as follows: I. United States Patents. II. United Kingdom, Australian, Canadian, and South African Patents. III. Belgium, French, German, Italian, and Swedish Patents. The domestic patents for this bulletin were collected between 1963 and 1955. Some of the Foreign Patents were collected at the same time and a few of them later in 1961. Part I was published in 1960; Part II was published in 1962.

Jan 1, 1964

High-sulphidation (HS) gold, silver and/or copper deposits are generated in both the epithermal and the upper parts of the underlying porphyry environments over vertical intervals of up to 2 km. The HS deposits are generated in advanced argillic lithocaps, which are products of the absorption of acidic magmatic volatiles by voluminous groundwater systems. Mineralisation styles in HS systems reflect depth of formation as well as the interplay between structural, lithological and hydrothermal parameters. The deep parts of HS systems, at depths of >1000 m, are typified by disseminated copper¦gold mineralisation comprising digenite, chalcocite and covellite in pervasive advanced argillic as well as underlying sericitic alteration. In highly telescoped systems, such mineralisation may overprint porphyry stocks and associated quartz-veinlet stockworks. Intermediate levels of HS systems commonly contain fault-controlled copper-gold mineralisation, typically as enargite in bodies of vuggy residual quartz, silicification and/or massive pyritic sulphide. The shallow parts of HS systems, at depths of The exploration focus is on four principal HS mineralisation styles:copper (eg Chuquicamata, Monywa) or copper-gold (Wafi) in the deep porphyry-hosted parts of systems preferably, in the case of the latter, where supergene oxidation is limited and, hence, flotation may be used for metal recovery; copper¦gold-bearing replacement mantos and pipes hosted by carbonate wallrocks in the deep parts of systems (eg Bisbee); high-grade gold in late-stage veins or hydrothermal breccias that overprint the intermediate to shallow levels of systems (eg El Indio, Goldfield); and large, bulk-mineable gold deposits in the shallow parts of systems that were subjected to supergene oxidation, thereby permitting heap-leach treatment (eg Yanacocha, Pierina). To these preferred HS styles may be added the low-sulphidation vein or disseminated gold¦silver mineralisation that is commonplace alongside many HS systems (eg Victoria at Lepanto).

Jan 1, 1999

By R. Boom, J. Halder, B. Snoeijer, B. Deo, A. Overbosch

Operational data of BOF and the slag samples for different starting conditions of phosphorus(0.06–0.26 per cent P) and silicon content (0.3–1.2 per cent Si) of hot metal have been analysed. The contribution of parameters that are well known to affect phosphorus distribution at tap, like basicity, temperature, FeO content of slag, slag mass etc., is investigated through the models of ionic theory of slag, optical basicity, regular solution approach and molecular theory of slag. The best overall results are obtained by the model based on molecular theory of slag in which several operational parameters are also incorporated. The investigations of different slag samples, based on optical, SEM, EPMA and X-ray studies, reveal the effect of MgO and Al2O3on slag morphology and phosphorus distribution in different phases. It is important to consider phosphorus distribution ratio in the solid and liquid part of slag. The solid part of slag, which is mostly dicalciumsilicate, can contain up to 5 per cent phosphorus. The phosphorus content of the liquid part of slag may depend upon the phosphorus content of hot metal or phosphorus load of slag. It is found that incorporation of effect of dicalciumsilicate in the model improves the accuracy of prediction. For better process control, the addition of iron ore towards the end of blow must be avoided while treating high phosphorus hot metal or during the production of ultra low phosphorus steels. Keywords: steelmaking, BOF, phosphorus distribution, slag morphology, MgO, Al2O3,dicalciumsilicate, process control, models

Jan 1, 2004

By L. G. Marshall

This report is one of a series published by the Federal Bureau of Mines, describing mining methods and performance at individual mining operations throughout the United States. The objective of these papers is to promote development and conservation of our mineral resources by disseminating reliable technological information on mining methods, practices, and performance. Limestone deposits in Iowa are extensive and reserves are large. Most of the past production came from the eastern third of the state, although over half of the counties in the state have produced, or are now producing limestone. The stone is used as aggregate, road metal, agricultural lime, riprap, fluxing stone, railroad ballast, and in the manufacture of cement and lime.

Jan 1, 1962

By R. H. Hiltz

One of the major hazards in underground coal mining is fire. The inherent hazard of fire is exaggerated by the nature of coal mining restricted areas, the highly combustible nature of coal itself, and a potential for explosive concentrations or dust and gas in the air it becomes imperative therefore to make every effort to eliminate the causes of fires, while providing the most effective means possible to control and extinguish those fires which may occur it has been demonstrated by prior work that the problem of control increases in proportion to the time necessary to institute control procedures. There are several areas of underground coal mining with obvious fire potential. Some of these, like belt heads, have reliantly undergone improvements in standby fire control devices Others, although having fire suppression systems available to them, have not received as complete a systematic study of their problems. Face machinery, particularly those without a water supply, falls in this latter category.

Jan 1, 1973

By John E. Kelley

A method for measuring the spark-shower radiance of metals when abraded on a grinding wheel was developed by the Bureau of Mines for evaluating the sparking tendency of metals. The radiance was measured in units of emissive power per solid angle per area of the detector. Over 100 metals were tested and rated relative to commercially pure iron. The metals tested included elemental metals, iron binary and ternary alloys, iron-carbon ternary alloys, commercial steels, nonferrous alloys, and a few hard-metal compounds. Some alloys were synthesized; others were obtained commercially. Alloys that possessed good strength properties were emphasized for selection. The results indicate that the spark-shower radiance of plain carbon steels and carbon alloy steels was greater than that of pure iron. Certain elements, particularly vanadium and chromium, reduced the sparking tendency of iron. Stainless steels and particularly nickel alloys displayed low spark-shower radiance. Some metallic elements had much lower radiance than iron; others, much greater. Plain carbon steels, heat treated to a variety of hardnesses, gave radiance values that generally increased with increasing hardness. The effect on sparking tendency of an increase in hardness of an alloy steel was studied. The sparking tendency increased with an increase in hardness to a maximum, then decreased with a further increase in hardness.

Jan 1, 1974

By Steven J. Schatzel, James Addis, K. Vaibhav Raj, Berk Tulu

The National Institute for Occupational Safety and Health (NIOSH) is conducting research to enhance methane control and mine ventilation practices at coal mines, as a method to mitigate hazardous work conditions. NIOSH researchers conducted case studies to investigate the effectiveness of existing systems and improve performance to decrease the potential for unplanned or excessive methane emissions. At one mine, drainage was influenced by hydrofracking inefficiencies where two of the six wells showed good frack development. Methane content was variable, from 300 ft3/t to 600 ft3/t. This paper also summarizes overburden movement during undermining and the estimated quantities of gas transported to the mine using FLAC3D and CFD modeling. The findings from this research effort highlight considerations based on specific mine conditions that may also be applicable to most longwall mines utilizing methane control systems.

Feb 1, 2025

By J S-L Chan

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Cu-Ag-Au mineralisation at Kluwih prospect in Eastern Java, Indonesia is related to a high-sulfidation hydrothermal system within a volcanic dome (2.35 × 1.7 km diameter). The mineralisation occurs mainly in steeply dipping, structurally-controlled quartz-enargite-pyrite veins (several centimetres to 2 m wide) and is hosted mainly in porphyritic dacite, volcaniclastic rocks and volcanic breccia of the dome and in an underlying andesite that yielded a zircon U-Pb age of 11.5 Ma.Short wave infrared spectrometer analyses were carried out for alteration mapping at Kluwih. There are two main stages of alteration produced by the hydrothermal activity. The alteration mineral assemblages indicate an advanced argillic alteration. The Cu mineralisation occurred in the form of enargite and subordinate chalcopyrite with an intergrown texture in the early stage. These mineralised veins are characterised by narrow pyrophyllite ± diaspore and dickite selvages (metres wide) and a peripheral K-muscovite envelope (sericitic alteration) up to 100 m wide. The K-muscovite envelope is zoned outward to Na-muscovite or Na-illite. Late-stage kaolinite and smectite alteration overprints the porphyritic dacite and may obscure the nature of early mica-clay alteration. The spatial distribution of different alteration assemblages suggests that the temperature of hydrothermal fluid increases with depth.Both the high-sulfidation mineralisation and advanced argillic alteration are suggested to be related to magmatic-hydrothermal fluids, which are likely to originate from an undiscovered deeper porphyry Cu-Au system below the porphyritic dacite. Based on alteration mapping results and comparisons to similar deposits, the porphyry intrusion could be up to 500 m below the volcanic dome. Further geochemical and mineralogical studies may help to target the potential underlying porphyry system.CITATION:Chan, J S-L, 2015. High-sulfidation epithermal Cu-Ag-Au deposit, Kluwih, eastern Java, Indonesia – alteration and implications for potential porphyry cu mineralisation, in Proceedings PACRIM 2015 Congress, pp 213–218 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Douglas F. Scott

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied an 11,980-acre part of the 33,300-acre High Rock Canyon Wilderness Study Area, CA-020-913B, in order to evaluate its identified mineral resources. No mineral resources were identified during this study, and no significant amounts of gold, silver, mercury, gem-grade opal, or placer gold are present. The study area is located in Washoe County, NV, about 53 miles southeast of Cedarville, CA. No mining districts or mineral production are known, and no oil and gas leases are in the area. No current claims are in the area; however, six placer claims were located in 1911 in High Rock Canyon near its confluence with Mahogany Creek.

Jan 1, 1987

By D. Bienstock

To develop a rugged catalyst capable of withstanding hydraulic attrition resulting from the oil-circulation process for synthesizing liquid fuels, use of an iron catalyst containing an active coating surrounding an inert solid core of metal was investigated. This massive-iron catalyst in the form of steel shot and lathe turnings was activated by partial oxidation with steam at 600° C, impregnated with alkali, and reduced with hydrogen at 450° 6. The massive-iron catalysts were resistant to oxidation and spalling, and a 6-month catalyst life was attained. Higher operating temperatures could be employed than with fused iron oxide catalysts, resulting in greater gasoline yields. Because the lathe turnings pack with void volumes of 70 to 90 percent, it has become possible to employ a fixed bed without the danger of cementation that occurs with fused iron oxides.

Jan 1, 1963

By S. Noll

Ventilation is an essential part of any underground mining operation. It provides fresh air for workers and machinery, keeps up an adequate mine climate and dilutes and dissipates noxious gases. Possible changes in the economic environment for mining in the future, e.g. increasing energy costs, will necessitate optimization of distribution of airflow within most mines. This paper discusses the scientific set-up for measurements as well as the behavior and influence of parameters of ventilation according to airflow distribution under consideration of technically possible set-ups of mine fans. This study was done in an underground mine with a flat seam room and pillar mining method.

Feb 27, 2013

By E V. Kislov

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Northern Baikal Ni-Cu province is located in Buryatia, south-east Siberia, and geologically is part of the Baikal-Muya volcano-plutonic belt. It is known for numerous PGE-Ni-Cu-bearing mafic-ultramafic intrusions of Neoproterozoic age formed in various geodynamic settings. All these deposits can be regarded as a single Ni-Cu ore cluster located near the Kholodninskoe Pb-Zn deposit, which is ready for mining. In addition, there are less studied, small dyke-like bodies with sulfide mineralisation that formed in a rift setting and may be enriched in Ni, Cu and PGE. Individually, the known bodies are of poor commercial value by their resources, but their close spatial association (<30 km) may make these PGE-Ni-Cu deposits economic in the future. This extended abstract seeks to provide a geological framework of the North Baikal Ni-Cu-PGE province, specifically at the north-eastern Synnyr rift hosting numerous small subvolcanic bodies with Ni-Cu sulfide mineralisation. Some small subvolcanic bodies contain industrial level Ni-Cu deposits (Shanuch, Cabanga-Musongati, Voisey’s Bay, Jinchuan, etc).CITATION:Kislov, E V, 2015. North Baikal region Ni-Cu deposits , in Proceedings PACRIM 2015 Congress, pp 297–302 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Robert L. Lappi

This report covers the final phase of a project demonstrating the economic efficiency of cross-ridge mountaintop coal mining. A demonstration mine was established at Big Wheel Gap in northeastern Tennessee. Not only was cross-ridge mining feasible for the selected site, but parallel cut methods could not be used due to a deficit in available spoil storage. Cross-ridge mining permitted coal extraction at a cost almost identical with costs simulated by computer projections using mathematical optimization techniques. No unexpected environmental problems were encountered. Volume I is accompanied by Volume II which describes the MATHMINE Mine Simulation System, software used to support the mining demonstration.

Jan 1, 1984

By N. M. Soonawala

Detailed regional geophysical and geochemical surveys, ground surveys and drilling were undertaken to follow-up the federal-provincial Uranium Reconnaissance Program (URP) over the 27,OOO-km2 Kasmere-Munroe area in northwestern Manitoba. An analysis of the URP data showed a fair correlation between the regional airborne radiometric results and lake-bottom geochemical results, both of which also correlated with the regional geology. More detailed surveys defined anomalies with greater precision within the broad zones outlined by the URP. The ground follow-up indicated that URP anomalies can be caused by varying degrees of uranium concentration in the rocks. Mineralization of interest was found in leucogranites at several locations within the survey area. Anomalous uranium concentrations were also found in coarse pegmatites and Hudsonian granitic intrusions. It can be concluded that large-scale regional surveys can be followed up in relatively short periods of time to yield meaningful results if a properly planned exploration sequence is employed, each stage of which successively narrows the area of interest.

Jan 1, 1979

By R G. Barker, A B. Christie

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. More than 11 Moz of Au and 50 Moz of Ag have been produced from epithermal deposits in New Zealand, almost entirely from 50 deposits in the Hauraki goldfield. Since the 1980s, new deposits have been discovered at Waihi (Favona, Trio, Correnso) and nearby at Golden Cross. Feasibility studies into reopening the Talisman mine at Karangahake are continuing, and advanced projects with preliminary inferred resource estimates are reported at Wharekirauponga, Neavesville and Muirs. In the Taupo Volcanic Zone, 11 prospects have been drilled, resulting in the definition of large but low-grade Au-Ag resources at Ohakuri. In Northland, several Au, Ag and/or Hg prospects are known, and small quantities of Ag and Hg have been mined. Six prospects have had some drilling, with the most advanced exploration at Puhipuhi. The application of Taupo Volcanic Zone geothermal systems research to the modelling of former hydrothermal mineralising processes in some epithermal prospects has enabled better targeting of exploration.CITATION:Christie, A B and Barker, R G, 2015. Exploration for epithermal gold deposits in New Zealand, in Proceedings PACRIM 2015 Congress, pp 533–540 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Donald A. Bruce

Various types of contemporary Deep Mixing Method (DMM) techniques have been used in the United States since 1986. Such techniques owe their origins to Japanese and Scandinavian developments, which began almost three decades ago. The growing demands of urban infrastructure development and rehabilitation have created a very active and rapidly expanding market demand in the United States especially since the early 1990s, and there is a clear need for a new and fundamental review of the surprisingly large number of DMM techniques that are being used domestically, or are available in other parts of the world. Following a summary tracing the historical development of DMM, and a generic classification of applications, the paper provides a review of each of the many different proprietary methods, which the authors have identified during preparation of an international survey funded by the Federal Highway Administration (FHWA). Data are also provided on commercial aspects of the various DMM techniques worldwide.

Jan 1, 1998