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By M. C. Radomsky

Approximately sixty, small, surface coal mines in Pennsylvania participated in a program designed to improve safety performance in the workplace. The method involved the use of safety sampling and observation to assess the safe standards of worker behavior and work conditions. Data were collected through the use of operation-specific, on-site safety records covering seven major occupational units. Workplace events observed (acts and conditions) were assigned a hazard classification; feedback, both immediate and delayed was initiated to improve safety performance. The experiences drawn from this pilot project have proven the need to continue to pursue this behavioral approach; however, a stricter methodology needs to be adopted in the collection and analysis of data.

Jan 1, 1987

By G. Mihaylov

The basic principles of systems analysis are presented. A model has been designed to determine the location of the Main opening in the presence of three or more stock orebodies. The necessary condition is to find a location for the Collection point which is an essential element in opening up each orebody (stock). The model takes into account the total transportation costs from each orebody to the collection point. Three variants are considered provided that the orefield is divided into two levels at least: - a collection point is designed at every level; - a collection point is designed at the lowest level, i.e. where the so-called concentration level is formed; - the collection point is located at a point between the planes of the two levels; The effect of the depth of mining and mine output on determining the method of opening up the orefield has been analyzed by considering a vertical and/or an inclined shaft. A function has been constructed which allows for investigating in both a static and dynamic regime the capital costs for constructing the whole complex including the shaft. The character of the function does not allow finding the global limits. Therefore, it is of particular importance to specify the limiting conditions. In this case these are the flow capacity of development openings and the shaft. The basic groups of cost and natural indicators for assessing and selecting an optimal technological solution have been systematized. The combined analysis of the two approaches to finding the location of the Main opening and determining the mining method enables us to determine when an inclined shaft is best, and the depth at which opening by a vertical shaft has no alternative. Thus, a transition area is formed for which the selection of an optimal technological solution requires an analysis similar to that proposed in this paper. Conclusions are finally drawn which serve as a basis for determining the areas of application of each opening, including the use of a combined scheme of mine opening. The approach presented can be used in both investigating the possibilities for opening up new orefields and reconstructing existing ones in cases when the mining operations go deeper.

Aug 1, 2013

By John E. Butler

Due to the present economic climate, particularly the depressed copper market, conventional mining, milling and flotation operations have been suspended. However, due to the apparent amenability of the ore to 'natural' leaching, investigations have been initiated into establishing an in-situ leaching operation as a preferred alternative to conventional operations. Cement copper production has been developed in parallel with the leaching trials and is presently at the rate of approximately 3,000 tonnes of contained copper per annum. Testwork includes controlled leaching of ore both in the laboratory and in-situ following blasting.

Jan 1, 1981

By Ingunn Opland, Silje M. Tinderholt

Drill and blast project in Norway’s capital. The contract consists of 7 rock caverns (350–950 m2), 9.2 km tunnels, and four shafts. With 110 blue-collar and 31 white-collar, the project produces an average of 16–21,000 m3 hard rock per week, with a total of 19 tunnel faces. Weekly, nine grouting rounds for water control, 800 m3 shotcrete, and 1,200 bolts are required, and 60 trucks leave the site pr. day. Challenges include blasting in densely populated areas, planning and coordination to maintain high production, obtaining a CEEQUAL certification of very good, and transporting rock on Oslo’s main highway.

Jun 13, 2023

By Martin J. Gavin

During the present study of lubricating oils in the San Francisco laboratory of the Bureau of mines it became desirable to distill oils used in the experimental work at pressures as low as 10 mm., (mercury column) absolute. In the effort to overcome difficulties and eliminate sources of error the apparatus described below was finally developed. The distilling flask is essentially the Hempel flask used by the Bureau of Mines for the analytical distillation of petroleum3. The complete apparatus is shown in Figure 1. As air leakage at connections is an ever present or potential source of difficulty and error in vacuum apparatus, the, mouth of the flask is drawn down to one cm. internal diameter which materially simplifies obtaining an air-tight seal at this point. Before reducing the mouth, the spray screen is inserted and adjusted in position.

Jan 1, 1927

By S J. Schafrik, C Keles, C Schlosser, E S. Gilliland, A K. Louk, N S. Ripepi, S Keim, J Amante, E Diminick

Three legacy coalbed methane production wells have been converted to injection wells for a one-year carbon dioxide (CO2) injection test to evaluate the potential for CO2 storage in the coal reservoir and the potential for enhanced gas production at offset wells. The injection reservoir is composed of 15–20 individual coal seams with an average thickness of 30 cm (1.0 ft), spanning a depth range of approximately 240 (800 ft) to 670 m (2200 ft).The monitoring program for this test includes gas and water sampling of the three injection wells, three dedicated monitoring wells and approximately 20 offset production wells. Key technologies used for monitoring the study area include time-lapse GPS and interferometric synthetic aperture radar (InSAR) acquisitions for surface deformation measurement, a 28-station buried passive microseismic monitoring array, real-time downhole pressure and temperature sensing and perfluorocarbon tracer fluids, which will be injected with the CO2 stream. The schedule for the monitoring program includes pre- (baseline), during- and post-injection data collection. This schedule will allow data to be analysed for time-lapse changes and trends, which are important for understanding the migration of gas and fluid phases in the reservoir – including CO2, methane, other hydrocarbons and water – and for observing the changing distributions of reservoir pressures and stresses.The results of the monitoring efforts for this study have implications for monitoring mining operations. The combined use of GPS and InSAR geospatial data to evaluate elevation changes across and beyond the study area may prove to be an accurate option for measuring surface deformation, including mining-induced subsidence, in unstable terrain. Long-term microseismic monitoring using high-sensitivity instruments has several applications in mining operations, including rock stability monitoring, production monitoring and miner location detection during emergencies. Tracer studies and short-term microseismic monitoring used to assess methane extraction can also be used to develop and optimise degasification systems for underground coalmines.CITATION:Gilliland, E S, Ripepi, N S, Schafrik, S J, Schlosser, C, Amante, J, Louk, A K, Diminick, E, Keim, S, Keles, C and Karmis, M, 2015. Monitoring design and data management for a multiwell CO2 storage/enhanced coalbed methane test in a stacked coal reservoir, Buchanan County, Virginia, USA, in Proceedings Third International Future Mining Conference, pp 47–56 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By Robert T. Mann

This paper is one of a series being prepared for and published by the United States Bureau of Mines on the quarrying, crushing, and grinding of limestone for cement manufacture. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total coats. It is recognized that publication of total costs might in many instances cause embarrassment to individual producers, as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of J. B. Thoenen, mining engineer of the Bureau of Mines, in the preparation of this paper.

Jan 1, 1933

By J. M. Singer

In this Bureau of Mines study coal and rock dust beds were entrained by airblasts generated by gas explosions at the closed end of a 0.61-m-diameter explosion tunnel, 49.7 m long. The system was designed to simulate entrainment of mine dust deposits by accidental gas explosion at the coal face of nonintersecting mine passageways. Full-scale mine explosion trials confirmed many of the results of the explosion tunnel experiments and indicated several new features of dust entrainment. Dispersal of 20.3-cm-long stepped dust beds located 35 m from the closed end always began during the early portion of the ascending gradient of the first transient airflow (and pressure) wave, and was usually completed before the end of the first quarter-wave period. Bulk quantities of dust were entrained simultaneously by longitudinal regression from the leading edge of the dust bed and by surface lifting of the top layer. Instantaneous threshold air velocities for bulk quantities of coal and rock dust beds in separate, mixed, and layered configurations were in the same range (5 to 30 m/sec) as previously found under steady-state velocity conditions. Selective lifting of coal dust layers from rock dust occurred when the threshold dispersal velocity of coal dust but not of the underlying rock dust was exceeded.

Jan 1, 1976

By Bobby P. Faulkner

Allis-Chalmers has combined a new heat transfer device, called the ROLLER GRATE, with a unique processing scheme, resulting in the ROLLER GRATE Oil Shale Processing System of Allis-Chalmers. In order to test both the process and the equipment, a batch Process Development Unit (PDU) ROLLER GRATE retort was designed and built. This unit vas designed with the flexibility to process shale over a wide range of test conditions in order to demonstrate the attributes of the oil-shale processing system. Instrumentation on the PDU and extensive sampling of the effluent streams permitted the PDU test data to be used in the design and scale-up of the process. Over 30 tests have been conducted with Colorado shale, and over 25 tests have been run with an Indiana shale. In addition, rests have been run with California and Utah tar sands.

Jan 1, 1983

By Curtiss O. Ehrsam, M. Naseem Mian

Alaska’s Red Dog Mine is strengthening its position within Cominco’s “Vision 2000”strategic plan by continually improving quality and quantity of production while reducing costs. Red Dog has evolved into a stable and mature operation, after six years of milling experience. A high grade, partially oxidized orebody in the severe Arctic environment, along with competing producers in a volatile metals market, are the continuing challenges facing Red Dog. The Red Dog Mine is striving to meet these challenges with emphasis on operator training combined with creative systems development and increased production. This paper describes developments in operations along with future plans.

Jan 1, 1996

By Patrick Clark

As part of the Mine Waste Technology Program (MWTP), a large-scale column test using bacteria and a sulfide ore was conducted at McClelland Laboratories, Inc., in Sparks, Nevada. Four technology providers participated in this demonstration. A mining company in Nevada provided the sulfide ore, process effluent and make-up water. A process effluent column, a chemical oxidation column, and the four biological treatment columns were set side by side on a test pad outside the laboratory building. The process effluent and chemical oxidation columns were used for experimental control. The goal of this project was to evaluate the viability and feasibility of using these biodegradation technologies to reduce the cyanide to the regulatory level of 0.2 parts per million (ppm) within an acceptable timeframe and with low operational costs. The column testing began on December 3, 1998 and operated until May 17, 1999. One technology provider reached the regulatory level within the 158 days. The remaining three biotechnology columns were approaching the regulatory limit at completion of the demonstration. The MWTP is funded by the U.S. Environmental Protection Agency (EPA) and is jointly administered through an interagency agreement with the U.S. Department of Energy (DOE).

Jan 1, 1998

JAmes E. Howard, Watertown, Mass.:—In connection with this paper, it is the desire of the Watertown laboratory to receive suggestions as to the lines of work and the particular direction along which the examination of the ingot-metal should proceed, and any suggestions so offered will be noted with care, and the tests conducted so as to embrace such features as it is thought desirable to have investigated. To me the question of structural continuity seems of para-

Jan 1, 1909

By Eddy Dierckx

Modernization of flat rolling plants is essential to sustainably fulfill increasing market demands and to improve competitiveness. Intelligent modernizations ensure getting maximum prime yield of existing mills, even if they have gone through half a century of operation. Existing mills were designed based on former production, consumption and quality targets. Ever increasing requirements such as increase of productivity, change of product mix (e.g. new steel grades), reduction of energy consumption and improvement of product quality lead to the necessity to adapt the existing equipment to the new target. SMS group provides, besides the reliable equipment and automation solutions to successful upgrades of existing mills, also a systematic approach to develop technical and economical solutions together with our customers (conceptual engineering). This paper describes the SMS group approach to modernizations / upgrades, introduces powerful performance modules and provides a number of successful examples that have been implemented recently.

Aug 17, 2017

By Jr. Hazen

Two statistical techniques, the mean-square-successive-difference test and correlation, are used to investigate the problem of assigning an area of influence to an assay. Data from five hydrothermal deposits, Climax molybdenum, Cebolla Creek titaniferous iron, San Manuel copper, Piedra Hueca copper, and Butte copper, are studied. Two groupings of the assays are used for the mean-square-successive-difference tests. One group involves an increasing sample volume by reaveraging assays to represent a longer sample intervals, the other by regrouping assays to represent longer sample intervals without a change in sample volume.

Jan 1, 1967

By D. C. Yang

A practical and economical flowsheet has been developed and demonstrated by integrating the packed column flotation with the GranuFlow process for fine coal recovery. Orimulsion, which was used as an additive, served a dual purpose: first in the flotation and second in the dewatering and granulation steps. The test results on the coal preparation effluent sample show that Orimulsion is flexible and compatible with fuel oil and various frothers used in the packed column. Clean coal with ash contents of 3.0, 3.7, 4.3 and 5.1% were produced from a head sample of 33% ash at combustible matter recoveries of 72.4, 81.1, 87.5, and 89.2%, respectively. Other advantages include high throughput, low moisture, improved handleability, and reduced dustiness of the dewatered coal, thus providing a very significant economic Incentive for the integrated process.

Jan 1, 1998

By S Maryati

Surface mining activities disturb large areas, produce great sediment loads and tend to be a source of water pollution if they are not managed properly. Coal mining in Indonesia has a very high risk of soil erosion because the coal mining areas are generally located in tropical areas with a high average of rainfall (4000 - 6000 mm/year) and use surface mining methods. The main factors affecting erosion risk are climate, soil type, topography, vegetation cover and management factors. Thus, the monitoring of erosion risk in mining areas is very important due to the characteristics of coal mining in Indonesia. The objective of this research is to determine the ability of satellite images (remote sensing data) and geographic information systems (GIS) to provide an accurate and up to date spatial database for the monitoring of erosion risk in surface coal mining areas using the Universal Soil Loss Equation (USLE) method.The erosion risk analysis and spatial data processing are generated by the ArcGIS 9.3 software and need several data, namely: an erosivity map, erodibility map, a slope map, vegetation index map and land management or land cover map. The erosivity map is derived from the rainfall data, whereas the erodibility map is derived from the soil map. The slope map is derived from the SRTM-DEM (Shuttle Radar Topography Mission-Digital Elevation Model) and processed using 3D analyst tools. Furthermore, the vegetation index map and land cover map are derived from a satellite image using digital image processing techniques.This preliminary study produced results that show soil erosion monitoring, which is integrated with remote sensing and GIS technologies, has great potential for producing accurate, advance, and low cost erosion risk maps in coal mining areas. This map is very important for getting spatial distributions of the erosion and useful for developing erosion management plans.

Nov 22, 2011

By Julian Malnic

Various natural, commercial, engineering and operational factors govern the evolution of approaches taken in the exploration for Seafloor Massive Sulphides (SMS) and in delineating the resource. These stages are prerequisites to the proposed mining of SMS deposits. This paper presents and analyses these factors from the view of an SMS exploration company that is pioneering the exploration of this rich alternative source of zinc, copper and gold. Current exploration practices developed by Marine Scientific Research (MSR) workers for SMS deposits are expected to give way to industry-generated methods as the SMS exploration industry gathers momentum. The exploration process falls into three phases that are described below: Prospecting (locating targets), Indicating Resources, and Measuring Mineral Resources Considerable streamlining of the SMS exploration process will accelerate the rate of discovery. The economics of SMS mining are projected to be superior to comparable terrestrial mining operations in both operating cash cost and capital terms.

Jan 1, 2001

By T. Harris

Exports of crude gypsum from Mexico currently comprise about 60% of all domestic shipments, and about 25% of the imported material consumed in the U.S. wallboard industry. However, of growing importance are the domestic markets for calcined gypsum in Mexico including building plasters and wallboard, which account for 55% of the internal demand for natural mined material. This paper will examine the current trends in the production and trade of natural mined gypsum in Mexico and North America and the opportunities and threats that are facing existing and new suppliers in this changing market.

Jan 1, 1996

By R.P. Edwards, B.C. Flintoff

Froth flotation is one of the most widely used and effective processes for mineral benefication. First introduced in 1911, flotation technology has seen many developments over the past 80-plus years. Innovations in reagent chemistry, equipment design, process analysis and process control have given design and plant engineers a powerful set of "tools" for process optimization. However, it does not follow that all flotation systems are optimized. As Klimpel observes: "The problem with the industrial flotation process is that it is relatively easy to get reasonable results, and relatively difficult to get excellent results." Klimpel [1988] While reasonable was sufficient in the past. competitive forces will make excellent necessary in the future. Judging by the activities in many Canadian plants this transition is already underway.

Jan 1, 1995

By J. E. Hawley

Abstract Spectrographic methods for the analysis of minor constituents such as platinum-group metals, gold, silver, and silica in palladium and platinum refinery sponge are described. These involve the conversion of the sponge metals to the black form by reduction with high purity aluminum filings in either acid or alkaline media. Standards of known composition are prepared in the same manner from either refinery or spectrographically standardized sponge metals. Samples of the black metals are mounted in pellet form and a multisource spark discharge used for excitation. The range of concentrations of impurities studied are those common to refinery samples. Excellent reproducibility of intensity ratios using major constituents as internal standards, is demonstrated and two methods have noted by which the accuracy of the procedures are shown to be of the order of 3 per cent, on the basis of synthetic preparations. Introduction During the past two years an investigation has been carried out in the Spectrographic Laboratory, Queen's University, to determine the suitability of modern spectrographic techniques for the precise analysis of the platinum-group metals palladium, platinum, rhodium, iridium, and ruthenium in the form of refinery sponge analyzing about 99 per cent of the major constituent.

Jan 1, 1951