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This report summarizes the results of the Narragansett Win Projec't's activities during the U.S. Bureau of Mines (BOM) Phase 1, which was transitional from and which followed the National Science Foundation (NSF) Phase which initiated the investigation of New England's potential roil resource. The 960 sq. mile basin is structural and topographic lowland containing 12,000 to 20,000 ft. of terrigenous clastic sediments of late Pennsylvanian age, and which rests on an upper Precambrian and Cambrian basement. The Rhode Island Formation, which is the coal-bearing unit, comprising the bulk of the Pennsylvanian rocks consists, in order of decreasing abundance, of sandstone, conglomerate, silts tone, shale, and coal. In the NSF Phase, 24 drill-holes yielded 17,900 ft, of core; in the BOM Phase I study, 4 drillholes yielded 2,100 ft. of core. Anthracite and semi-anthracite was encountered in beds Up to 30 ft. thick in widely spaced parts of the Basin. The coal, typically very low in sulfur, and a high ash anthracite, won mined in substantial volumes from 1808 to 1959 from shaft and open lit in Portsmouth and Cranston, R.I., and in lesser volumes in Mansfield, Mass. Currently coal is now being mined in Plainville, Mass. as a fuel in the manufacturing of light-weight aggregate from the same quarry that serves as the source of the rock being processed. The structurally complex Narragansett Basin is now known to have a greater extent than earlier since recent drilling by others (Chapter 2) has confirmed our interpretation that the Basin extended offshore south A Boston. The, Basin also extends into Rhode Island Sound to the south. The geological structure is more complex in the southern part of the Basin than in the northern part. Three episodes of folding have been documented on Aquidneck Island and four episodes of faulting have been demonstrated for the Basin as a whole. Relatively less well exposed rock in the northern part of the Basin, increases the difficulty of recognizing and correlating structural episodes in the northern part of the Basin. The Basin his hewn subdivided into six structural domains which appear to have distinctive structural, metamorphic, paleontological and sedimentological differences that mw assist in isolating important events in the evolution of the Basin and its component parts. The tentative structural model recently developed in POP Phase I has important implications for exploration and mining. In the first and second folding stages the coal is mobilized and thickened in the crests and troughs of folds whose axes are horizontal to subhorizontal. While conventional coal exploration and mining methods are not applicable, great thickening in the crests and troughs of large scale structures, which can he defined by geology, geophysics and drilling, may provide compensating advantages. Bedrock over most of the Basin is 0-50 ft., but thicknesses of glacial deposits up to 150 ft. are present locally. Pro-Pleistocene topographic trends are controlled by structure and rock hardness; Pleistocene deposits aligned to the S. F. are superimposed on earlier trends. The southern part of the Basin is mainly dominated by high grade Barrovian metamorphism and plutonism of Permian age, related to the Alleghanian Orogeny. About 300 sq. miles of the 960 sq. mile Basin has been affected. The remaining 660 sq. miles, in the chlorite and subchlorite zones of metamorphism are compatible with the presence of high quality anthracite and semi-anthracite. Illite crystallinity studies begun in the NSF Phase, have been carried out in the BOM Phase l with important results. About ME of the northern Basin is now known to be in the diagenetic (unmetamorphosed) or subchlorite zone and the remainder in the chlorite zone of metamorphism. Mite studies, probably best recording temperature effects, show a generally progressive increase from the NW corner of the Basin near Plainville, Mass. toward the south and southeast. Reflectivity and coal petrography studies, probably best recording pressure and effects related to shearing, indicate a generally opposite pattern. Thus these methods provide powerful tools for the ultimate solution of problems important to coal exploration for coals of higher combustible volatile content and exploitation of these. Due to the complex nature of the coal, chemical data may not he easily used to determine rank. The coals have been tectonically deformed and mineralized. This deformation plus thermal metamorphism have altered the coals, in some cases by producing natural coke. Brecciated coal is often coated with a secondary depositional carbon. The coals' hydroscopic nature and high ash contents are due to the deformed nature of the coal and the presence of this secondary carbon. The stratigraphy and sedimentology of the coal-bearing Rhode Island Formation is similar to described alluvial fan deposits. The non-geological studies al-low three conclusions to be made: 1. A substantial number of areas have been identified in the Narragansett Basin in which mining could be carried out without undue difficulty from a land use point of view. 2. Substantially more than two hundred instances of past or current- mining activities have been identified in the Basin. Many of those are in areas defined as geologically interesting, and may be advantageous From the point of view of future exploration. 3. The map synthesis technique developed for this contract is successful and may easily be adapted to future exploration in its current form and also in its expandable form dealing with unit measurements of one-tenth mile. We recommend that BOM Phase 2 exploration should accomplish the intent of the Congressional language in House Report No. 95-1251, to continue a substantial drilling and geophysics program: "The Committee expects the Bureau to continue studies involved in ascertaining the extent and quality of low sulfur coal reserves in the Narragansett Basin in New England including necessary drilling and geophysical studies. The knowledge of the extent of such deposits is of great importance to this 'energy pour' area".

Jan 1, 1979

By Larry A. Lass

The U.S. Bureau of Mines, in cooperation with the Iron Range Resources and Rehabilitation Board, investigated the potential of using northeastern Minnesota papermill waste sludges as a binder for Mesabi Range iron ore (taconite) concentrate. Sludges from five different commercial papermill waste treatment operations were evaluated in laboratory tests. Except for the coarsest sludge, all were fairly easy to blend with the taconite concentrate using conventional mixing methods. The coarsest sludge had to be reslurried at 2 pct solids before adding it to the concentrate in order to obtain pellets without visible sludge clumps. Drying and grinding the sludges made them less effective as binders because of a lower degree of rehydration. On a dry weight equivalent basis, twice as much raw sludge binder was required to obtain similar pellet physical properties as with bentonite; however, the pellets made with raw sludge had superior metallurgical properties. Over 30 pct higher reduction rates and over 1500 C higher softening temperatures were obtained with sludge binder than with bentonite. Sludge D, which had the lowest fiber and the highest alkali metal content, resulted in the lowest reducibility enhancement. Even though more raw sludge was required than bentonite, the sludges have virtually no value, and therefore may provide a cost-effective additive binder for producing improved metallurgical-quality pellets. Large-scale testing has not been done to confirm these laboratory results.

Jan 1, 1989

By Greg Wyartt

In the Pilbara region of Western Australia, an iron ore mine is undertaking a high wall cut-back to improve stability and allow access to deeper ore deposits. Several sections of the wall have been classified geologically sensitive due to unstable localised geology, and therefore an engineered approach to vibration critical blasting was required. The use of electronic detonators allowed multiple signature (seed) holes to be incorporated into a production blast adjacent to the geologically sensitive area, therefore providing baseline vibration data to be used for future modelling with the added advantage of eliminating unnecessary pit closure downtime typically associated with a signature hole program. All subsequent blast patterns also incorporated multiple signature holes to provide additional data and allow continual updating – and therefore improved accuracy - of the blast prediction model.

Jan 1, 2018

Properties of coal which are significant in relation to preparation for carbonization and conversion are reviewed, and existing coal preparation technology which has been used for production of cleaned coal of suitable ash content and petrographic composition for carbonisation, pyrolysis, hydrogenation and similar processes is described. Possibilities for application of this technology to some Australian coal seams is examined briefly. It is concluded that further survey work is required related to the optimization of selective crushing and concentrating operations, with the aim of maximizing production of quality products for carbonisation, etc mainly from Australian seams with only moderate coking characteristics.

Jan 1, 1980

By E. P. Youngman

Tantalum is a rare element ; estimates indicate that there is less tantalum than gold in the earth's crust . After remaining a laboratory curiosity for many years , it was used to a limited extent and for relatively few years (1903- 1911) for incandescent electric-light -bulb filaments . Another wave of interest in tantalum appeared when its electrolytic-valve action was taken advantage of in charging storage batteries , especially for radio work . Tantalum chargers were eventually displaced by other types of chargers , but for a time they were manufac tured in sufficiently large numbers to create a demand for the metal and to bring about its production on a commercial scale in the United States . As tantalum became available in larger quantities and at substantially lower prices , and as high prices for platinum encouraged the employment of tantalum as a substitute , the metal was put to many new uses . Ferrotantalum was made and sold before the World War , and patents have been taken out for a number of special alloys for industrial purposes , but probably the largest use for the metal to-day is in vacuum tubes .

Aug 1, 1930

By Daniel Hodouin

Artificial neural networks (ANN) are of growing interest in a wide variety of applications. Pattern recognition, speech processing, financial analysis, signal processing and process control are at present the most successful ones. This paper is an attempt to illustrate the potentiality of ANN applied to mineral processing. An introduction to the technology of ANN is first proposed to describe the various components and to explain the various phases encountered in setting up a network. Then examples are given to illustrate the use of ANN dynamic modelling of mineral processing units or plants and in process control.

Jan 1, 1991

By William L. Rice

This Bureau of Mines Open File Report on nickel is one of a series of minerals availability commodity deposit abstracts. Nonconfidential information from the Minerals Availability Program data base covering domestic and foreign nickel properties and deposits has been abstracted for use in this report. Abstracts include applicable data on location, published reserves and resources, geology, mine and beneficiation systems, and operation information.

Jan 1, 1984

By Flavio Rojos-Tapia, Oscar Pereira-Cerda, Samuel Sánchez-Pino, Samuel Sánchez-Baquedano

"Pneumatic flotation was introduced to the Chilean Copper Mining Industry in 1993 by Ingeniería de Minerales S.A. (IDM). The technology is based on the designs of Dr. Rainer Imhof from Germany, who is the designer of several different types of pneumatic flotation cells, already sold through his Company Maelgwyn Mineral Service Limited (MMH). The company is represented by Ingenieria de Minerales S.A. (IDM) in South America.Pneumatic flotation, has been used in tough industrial applications .It has been successfully used for metallic ores such as copper sulphide and oxide minerals, copper slag, silica and silicates from iron magnetic preconcentrate (reverse flotation) and gold. It has also provided promising results when applied to molybdenum flotation. The latest applications, with ultrafine molybdenum particles in operating plants, is showing the V and G Cell (end model designed) as a real technological alternative to conventional flotation., The G Cell is an extremely high speed flotation machine with high selectivity which introduces the possibility of producing a final molybdenum concentrate with only one stage of cleaning. This is a completely new development in molybdenum flotation in the industrial circuit which has the potential to dramatically reduce the circulating load in the cleaning circuit. As a consequence the capital costs of future Molybdenum plants may also be reduced. The suitability of the G Cell will have to be determined on a case by case basis but it provides the metallurgist with an alternate flowsheet for consideration.The good performance of the G Cell can be explained by the high gas hold-up and very effective micro-turbulence which helps improve the attachment of solid particles to the bubbles. This technology may change our traditional concept of residence time in flotation. Additionally, the rotation phenomena introduced in the vessel of the G Cell ,creates radial separation forces which are critical to achieving a more rapid separation of the target minerals from the tailing. This results in a much reduced residence time requirement in the flotation machine. Some benefits associated with the use of the new G Cell are: less energy consumption, less maintenance costs, simple and reliable circuit to operate and a small area required for installing the circuits.As a result of the industrial experience in the Chile, the pneumatic flotation type G Cell can be regarded as a technology which must be considered as a replacement technology for the rougher and cleaner stages for fine particle flotation."

Jan 1, 2008

Factual data about the sedimentation in the Newcastle Coal Measures are presented. Data concerning the total coal measure sequence (isopachs, sand/shale ratio, and total coal thickness variation), data about three coal seams (Borehole, Dudley, and Victoria Tunnel) and data about interseam conglomerate units are discussed.From this data conclusions are drawn about the coal measure environment. The western edge of the coal basin, the Lochinvar Dome, although a high feature, was apparently stable during coal measure time. Despite its height it apparently supplied little sediment to the basin.The northern and north-eastern edge, which was unstable, supplied most of the coarse detritus (including the conglomerates) to the basin. The conglomerates show patterns of fluvial origin but after a period of "normal" variations in pattern they become restricted to two parallel zones evidently tectonically controlled. Deposition of conglomerates is episodic and separated by periods of coal formation when deformation was apparently slight. Formation of each of the three seams considered followed a rather similar pattern- each show development of thick coal around the basin edge and poor thin coal in the "axial" region of the present synclinal structure.Evidence of ill situ formation of some areas of the seams is discussed and periodic deformation of the basin during coal measure time is postulated.The unusual character of this coal basin, in particular the very coarse units, is stressed, despite the presence of many "normal "coal basin features.

Jan 1, 1970

By Dale Preece, Stephen Chung, Qian Liu

Stoping is one of the widely adapted methods in underground mining. In this method, fanned or parallel holes are often drilled from a top sill down to a sub- level in the ore zone and blasted ring by ring into a stope for excavation. At Brunswick Mine of Canada, this technique has been used daily in conducting production blasts. However, when mining into the West Ore Zone, it has been identified strategically that a mass stope blast, involving the blasting of rock from the 3-sub level down to the 1-sub level, should be considered to ensure the safe operation and regaining of access to the trapped main ore zone. The challenge of this mass blast lies in the control of ground vibration and precise timing for blasting 800 holes drilled in six blocks from three different levels within 6.5 seconds, to allow sufficient void to be created in each level for the muck moving in order from the upper to the lower levels without bridging. This paper describes stope blast simulations using a discrete element computer code for modeling blast-induced rock displacement in conjunction with a precision electronic programmable delay timing system for various stope geometries including a drop raise blast at the start of the mass blast. The modeling concept is also described in the paper.

Jan 1, 2003

By L. Li

The backfilling of underground stopes is a common practice throughout the mining industry. The stresses imposed by the backfill on the surrounding rock mass need to be assessed because of their influence on ground stability and on the hydro-geochemical response of the fill material. There is, however, a complex interaction between the relatively soft backfill and the much stiffer adjacent rock mass. In recent years, the authors have presented results from investigations conducted on stress distributions (obtained numerically and analytically) in and around backfilled stopes with (sub)vertical walls. In this paper, the influence of stope inclination and of backfill properties is evaluated. Results indicate that, in general, the vertical and horizontal stresses in inclined stopes are close to, but somewhat smaller than the stresses in vertical stopes. Nonetheless, significant differences can be observed in some cases, especially for the vertical stress along the inclined central line and along the hanging wall. It is further shown that neglecting deformability in limit equilibrium analyses is an acceptable assumption. However, Poisson?s ratio and the dilatancy angle, usually neglected in limit equilibrium analyses, may have significant effect on the stress distribution. Results also confirm that the backfill strength parameters (cohesion and friction angle) are critical factors required to properly evaluate the stress distribution, at least within a certain range of parameter values.

May 1, 2007

By Abdurrahman Cetinbas

The effect of water infusion on the flow of methane and on the production of dust was investigated at an active face in the Pittsburgh coalbed. The average total flow of methane at the face decreased by approximately 79 percent, whereas the flow from the ribs increased about 24 percent after infusion. On the day after infusion, dust concentrations appear to have been reduced; however, the presence of large quantities of rock dust obscured the results on the following days.

Jan 1, 1972

By T. M. Barczak

Stoppings are required to resist lateral forces on the face of the structure to control pressure differentials created by ventilating air. The design criteria in other parts of the world, including Australia, exceed this requirement by specifying over pressurization control to as much as 14 kPa (2 psi) in the active sections and 35 kPa (5 psi) in the main ventilating control areas. This is done to provide protection to the mine workers from explosive or air blast events within the mine that can create this over pressurization. The National Institute for Occupational Safety and Health (NIOSH) has been conducting research to develop a new testing protocol for rating mine ventilation stoppings. The premise of this work is that arch-loading conditions more accurately reflects the transverse load capabilities of stoppings in underground coal mines than the freestanding flexural strength test specified in the current Code of Federal Regulations (CFR). This work clearly shows that the transverse load capabilities of dry-stacked, mine ventilation stoppings are dependent upon the material strength of the block and the height and thickness of the wall, none of which are part of the current CFR criteria based on ASTM E-72 specifications. This paper compares the transverse load capabilities of several block materials and wall dimensions commonly used in stopping constructions based upon simulated three-hinge, rigid-arch loading tests of half-wall constructions in the NIOSH Mine Roof Simulator. The results indicate a wide-range of transverse load capacities, ranging from as low as 21 kPa (0.3 psi) to as much as 117 kPa (17 psi) for the conditions evaluated in this study. The current CFR criteria do not distinguish between applications of these stopping designs despite their wide variance in transverse load capabilities, which is not conducive to employing ventilation control strategies that isolate certain sections of the mine to prevent injury to mine workers.

Jan 1, 2009

By William O. Vanderburg

This report3/ gives the results of a reconnaissance of mining districts in Eureka County, Nevada, made from September 25 to October 20 and from October 27 to November 5, 1577. During this time, virtually all the districts were visited and many data obtained on active and inactive properties. This report covers the locations of the various districts, geological background, ownership and brief descriptions of mines and prospects, information on past and current operations, and, other data likely to be useful to those interested in the development of our mineral resources. From the viewpoint of past production in the county, the silver-lead-gold deposits at Eureka have been tie most important, followed by the silver deposits at Cortez and Mineral Hill. The period of greatest activity in the foregoing districts was from 1870 to 1990, when Eureka was one of the principal mining areas in Nevada; the production of lead was sufficient to affect its price in all the commercial centers of the world. Eureka also merits the distinction of being the birthplace of the silver-lead smelting industry in the United States.

Jan 1, 1938

By Jan A. Nemcik

Steel mesh has been used successfully for many years to control friable roof conditions and prevent loose roof and rib material from caving into the roadway. Despite its extensive use, the installation of steel mesh is difficult to automate and many other products have been evaluated as an alternative for skin control. Ideally, the properties of these new products should be similar or better than those of the steel mesh. In particular, development of a strong and resistant shell that minimizes movement along the fractured rock and coal surfaces between the bolt anchors is recommended. A strong surface adhesion and the strength of a reinforced polymer skin can provide the necessary toughening mechanism required to enhance roadway surface support by forming a reinforced polymer/rock surface layer. Most of the Thin Spray-on Liners (TSL) evaluated in the mines are weak with slow curing times, and the plastic mesh currently used to support the coal ribs is relatively weak. Therefore, neither material can seriously compete with steel mesh. Currently, a new polymer product that cures in seconds and forms an instantaneous strata binder that surpasses the properties of steel mesh is under development at the University of Wollongong.

Jan 1, 2009

By R. P. Jensen

This is a sampling of the papers presented at the conference, the proceedings can be bought from the SAIMM Arbitrary Lagrangian Eulerian (ALE) computational techniques allow treatment of gases, liquids and solids in the same simulation. ALE methods include the ability to treat shock waves in gases, liquids and solids and the interaction of shock waves with each other and with media from one of the other categories. ALE codes can also treat explosive detonation and the expansion of the explosive gases and their interaction with air and solids. ALEGRA is a 3-D ALE code that has been developed at Sandia National Laboratories over the past few years. ALEGRA has been applied to a 2-D simulation of presplitting using decoupled explosives in rock blasting with very interesting results. The detonation of the explosive at the bottom of the hole sends a shock wave up the borehole driven by the explosive gas expanding into air. The explosive gas compresses the air against the stemming column where it rebounds and recompresses at the bottom of the borehole. This type of ringing takes several cycles to damp out. The explosively induced expansion of the borehole is also treated by ALEGRA as well as the shock wave imparted to the rock. The presentation of this paper will include several computer animations to aid in understanding this complex phenomenon.

Jan 1, 2000

Mount Isa Mines Limited (MIM) and the Commonwealth Scientific and Industrial Research Organization (CSIRO) have, over the past 15 years, jointly developed the Isasmelt process. This process is based on the use of the Sirosmelt top-entry, submerged combustion lance, developed by the CSIRO in 1973. While the Isasmelt technology was first applied to lead smelting, it has more recently been adapted to smelt copper concentrate. A 15 t/h demonstration Copper Isasmelt plant was commissioned in MIM's Mount Isa copper smelter in April 1987. The success of the Copper Isasmelt demonstration plant, which smelted over 532,000 metric tons of copper concentrate, has led to the construction of two full-scale furnaces: a 104 t/h furnace in the Mount Isa copper smelter, and a 585,000 t/y (650,000 short t/y) furnace at the Cyprus Miami Mining Corporation smelter at Miami, Arizona. The commissioning of these furnaces commenced in August and June 1992, respectively. The MIM Copper Isasmelt furnace will raise the Mount Isa copper smelter's capacity to 265,000 t/y of copper. The plant includes several innovative features, including: Andritz pressure filters, a rotary holding furnace, and an Ahlstrom flux-flow boiler.

Jan 1, 1993

By A. Duerksen

"Surface coal mining in West Virginia has supplied energy to the eastern coast of the United States for over a century. Over the years, the coal mining industry has been forced to adapt as societal demands regarding health, safety, and environmental impacts have changed. More recent pressure has called for another iteration of change: long-term post-mining sustainability. The research discussed in this paper investigates one potential solution - or component of a solution - to improve the sustainability of surface coal mining in West Virginia: post-mining wind power. The paper begins with an introduction to the Appalachian region of the U.S. and the role that mining has played in its history, followed by a discussion of the need for sustainable mining and how post-mining wind power may help fulfill it. Data processing methodology of field data from monitoring locations is then explained. The results are then used to estimate the electrical output of a wind turbine. This data is then utilized in a case study discussion of one of the monitored sites. The paper concludes with an analysis of the broader implications of the research and a discussion of future work."

Jan 1, 2011

By Ray Wood, Rene Sterk, Robin Falconer, Sean Aldrich, Simon Nielsen

"The Chatham Rock Phosphorite project is situated 450 km east of New Zealand at approximately 350 to 450 m water depth. The deposit occurs as a thin layer of phosphatebearing glauconitic sand at the surface of the sea floor and has a thicknesses typically ranging from 0 to 1 m. The sand layer consists of mainly silt and sand-sized sediments, with phosphatised chalk nodules up to 15 cm in diameter. Phosphate nodules were first discovered on the Chatham Rise in the 1950s by a New Zealand Government survey. During the 1960s to 1980s several private and government sponsored cruises explored the Chatham Rise and surrounding seafloor area. A total of 1174 samples were collected over a 600 km2 area with the majority of the samples collected using a pneumatic -or large Van Veen-style grab-sampler.Since acquiring the licence in 2010, Chatham Rock Phosphate Limited has conducted six cruises in two programs in the Project area. A total of 261 samples were collected using a Van Veen grab, box core and grab samples.Sample quality and QA/QC measures varied considerably between the cruises and within each cruise. A critical part of the assessment of the data collected in the Project area was to determine what quality thresholds to use to allow or disallow data to enter into the estimation process. As part of the data verification process, the relative and absolute quality of the data was assessed in as much detail as practically possible. The best samples were those that were collected using the pneumatic grab, sampled the full sand horizon, had a small location survey error and had no other apparent data ambiguities. This paper describes the challenges for mineral resource estimation for an unconventional style of mineralisation using unconventional sampling techniques."

Sep 1, 2014

By M Scoble

This paper will report on the application of data collected through the performance monitoring of large diameter surface rotary blasthole drii and electric mining shovels, in an integrated approach to blast optimizatiion.

Jan 1, 1992