Search Documents

By K. A. Lapakko, D. A. Antonson

Fourteen samples of pyrite-bearing Archean greenstone rock (d < 6.35 mm, 0.04% < St < 1.22%) were characterized (particle size, chemistry, mineralogy) and subjected to laboratory dissolution testing. The only sulfide and carbonate minerals identified were pyrite and siderite, respectively. Quartz, chlorite and sericite typically comprised 90 to 98 percent of the mineral content. For the first 60 weeks, seven samples with sulfur contents less than or equal to 0.16% produced drainage pH values exceeding 6.0. Over this period, six of the seven samples with sulfur contents greater than or equal to 0.20% produced drainage pH below 6.0, with minimum values ranging from 3.2 to 4.7. The seventh sample (0.72% S) had a siderite content of 18%. Small amounts of magnesium and, to a lesser degree, calcium carbonates present in the siderite apparently dissolved to neutralize acid and maintain drainage pH above 6.0. Sulfate release rates generally increased as sulfur content increased, and the rates of pyrite oxidation estimated for individual samples were roughly half to five times that reported in the literature for the abiotic oxidation of pyrite by oxygen. Observed neutralization potentials ranged from 0.2 to 2.0 g CaCO3/g rock.

Jan 1, 2002

By Denise Crocce Romano Espinosa

The recycling of waste of electric and electronic equipment (WEEE) is one of the main modern challenges. Among the variety of WEEE, batteries can be set apart due to their composition and their growing demand along with portable devices. The objective of this work is to characterize the thermal behavior of a sample of mixed types of batteries using a thermobalance (TGA). The results of tests showed that Cd evaporated up to 800ºC, Zn evaporation occurred mainly above 900ºC and manganese oxides were pre-reduced to MnO at temperatures above 900ºC.

Jan 1, 2009

By P. Bousquet

Acid mine drainage (AMD) is a serious environmental problem that preoccupies the Canadian mining industry. Considerable amounts of money are spent every year in an effort to prevent or reduce the acid mine drainage phenomenon. AMD occurs when sulphide minerals (e.g., pyrite) contained in rock are exposed to air and water and subsequently oxidize to produce low pH water. This acid effluent has the potential to mobilize any heavy metals contained in the rock. Coating the sulphide minerals with silicates is a new promising technology to reduce AMD. Pyrite is treated with a solution containing H2O2, sodium silicate and a buffering agent. H2O2 oxidizes a small part of pyrite producing ferric iron (Fe3+) ions. These ions subsequently react with the silicate ions to produce ferric hydroxide-silica that precipitates on the pyrite surface producing a passive coating. This silicate coating can protect the grains of pyrite from oxidation. This paper presents a series of experiments that confirm that silicate coating can considerably reduce AMD.

Jan 1, 2002

The overall objective of this study is to gather operational data from selected surface coal mining systems in the United States, and to assess the potential production and economic capacity of the systems. The study includes: four mines, each using a different mining technique and different equipment. One mine was selected from each of the major coal fields: Midwestern, eastern,, northwestern, and southwestern. The Midwestern Mine is located in the Central Plains and produced 1.45 million tons of raw coal during the study year The Midwestern Mine uses the area mining or box-cut technique. A large in-pit shovel and a bucket wheel excavator are used to remove the overburden. Coal is removed by a loading shovel and transported to the dumping point by large off--highway trucks.

Jan 1, 1975

Jan 1, 1943

Jan 1, 1943

Solid Energy New Zealand Limited owns and operates the Ohai coal field (Wairaki Coal Mining Licence, CML) in western Southland. The Morley Stream passes directly through the middle of the CML and has required diversion in the past to enable open cast mining to proceed. Solid Energy is evaluating two new open cast pits at Ohai. Commissioning these new pits would necessitate further diversion of the Morley Stream. One of these potential new mines is adjacent to an abandoned State Coal Mines (State Coal) pit and there is an opportunity to substantially rehabilitate this old pit as a corollary to the new mine and the stream diversion project. &nbsp; Past Morley Stream diversions were undertaken by State Coal and so they predated the Resource Management Act 1991 and the degree of community environmental awareness and involvement that has become the norm these days. Not surprisingly the design and construction of the historic stream diversions was based purely upon mining (operational) and engineering considerations. This led to the stream being diverted in a manner that achieved the clinical conveyance of design volumes of water from points A and B. &nbsp; Solid Energy realised that the proposed new diversions need to adopt more holistic and environmentally sustainable design principles while also including appropriate mining and engineering constraints. This project involved the design of a 1.7 km diversion of the Morley Stream (median flow of about 1000 litres/second) that would enable progressive prestripping and development of the new mines and would also address final rehabilitation (of the stream), geotechnical risks, hydrological and ecological issues. To address all of these factors the project required a multidisciplinary approach. Moreover, it required a clear understanding of how the mining operational constraints could be integrated with the environmental considerations. A significant aspect of the project was how to take account of fishery instream habitat needs, the resource consent requirements and most of all, the involvement of key stakeholders such as the Fish &amp; Game Council, Department of Conservation, the Iwi and local community in the design process. This was achieved through coordinated consultation and stakeholder involvement in a technical design workshop.

Jan 1, 2005

By Neal M. Muir, Robert S. Sanford, Bruce I. Thomas

"INTRODUCTION The presence of the zinc-lead-copper deposits an the north slope of Mount Eielson, Mount McKinley National Park, Alaska, has been known for many years. The deposits were examined by J. C. Reed, a geologist of the United States Geological Survey during the summer of 1931. In the summer of 1943 the authors and Clyde Wahrhaftig, a geologist of the Geological Survey, examined the deposits.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the and that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual investigative work, and prepares the final report. The Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and performs beneficiation tests.Particular acknowledgment is due to Heine Kenworthy, who conducted the beneficiation tests under the supervision of C. Travis Anderson; to Clyde Wahrahaftig of the Geological Survey, who completed the Geologic and topographic maps, to Grant Pearson of the National Park Service; and to O. M. Grant and Mrs. Frank McGarvoy for their assistance during the examination."

Nov 1, 1947

By E. L. Rawlins

The development of commercial natural-gas reserves in the Michigan stray sandstone horizon of central Michigan during the past few years has resulted in expansion of the natural-gas industry in that State. The location of the natural- gas reserves of Michigan in the general vicinity of domestic and industrial markets is of economic importance, and in supplying these markets with natural gas a reasonable knowledge of the extent and availability of the reserves is needed in formulating regulations for drilling gas wells and producing natural gas, in analyzing the feasibility of projects to construct natural-gas transmission lines, in promoting and developing markets for the domestic and industrial consumption of natural gas, and In solving many engineering and economic problems common to the natural-gas industry. The development of the natural-gas industry in Michigan has been related closely to the development of oil production. The potential oil production of Michigan is comparable with that in most of the eastern oil-producing States. The development of oil production probably will continue, especially in the central Michigan Basin area; and as wells are drilled to deep horizons in the search for oil, more knowledge will be obtained of the gas reserves in formations above the oil- bearing horizons.

Jan 1, 1936

By Lon D. Santis

This paper summarizes explosives transportation incident and accident data collected by the U.S. Department of Transportation (DOT) from 1993 to 1998. The paper briefly describes the legislation and regulations that cover hazardous materials transportation. The multimodal incident data collected by the Research and Special Programs Administration (RSPA) contained 86 incidents involving Class 1 materials during transit. Thirty-two occurred on public highways. The Federal Highway Administration (FHWA) data showed there were 8 1 motor-vehicle accidents involving explosives. The FHWA Crash datafile extract contained 649 records categorized as involving Class 1 materials although closer analysis revealed that nearly 90% of these did not involve explosives. In both databases, there were no fatalities caused by the explosive materials although 7 fatalities were the result of injuries suffered during the motorvehicle accident. There were also no serious explosions during any of these incidents or accidents. The paper concludes with an analysis of the risk involved with transportation of commercial Class 1 materials on the highway.

Jan 1, 2000

By Wolfgang Van Hooff

Encouraged by a strongly growing and evolving market for granulated products, Paul Wurth continuously improves its granulation and dewatering technologies to provide customers with state of the art installations. Continuously developed know-how about the granulation process of iron blast furnace slag enabled application to non-ferrous materials such as Ni-Slag, Pb-Slag, Blister Copper, Cu-Matte and even TiO2-Slag, which rank among the most difficult materials to granulate. This paper identifies how critical objectives in granulation and dewatering technologies applied to different molten materials with respect to various product quality objectives can be addressed. The differences between hot and cold water granulation systems are explained, including the step from cold runner to granulation water tank. Development of a flow and pressure controlled blowing box is the latest step to optimize the granulation process in order to meet the latest standards in terms of quality, power consumption and environmental protection.

Jan 1, 2006

By Robert L. Lagace

This final report documents the work done by Arthur D. Little, Inc. (ADL) on behalf of the U.S. Bureau of Mines, Pittsburgh Mining and Safety Research Center (PMSRC), on Contract R0122026 (which began in August of 1971). Under this contract ADI provided technical assistance to the Bureau on a task basis on virtually all aspects of the Bureau&apos;s programs related to present and planned emergency and operational communications and miner location systems for underground coal mines. The work consisted of independent investigations, analyses, experiments, breadboard and prototype hardware development, workshops and technology transfer seminars on mine communications, and on-going evaluations and guidance related to the Bureau&apos;s contracted programs on electromagnetic noise, mine communications systems, and trapped miner location. This final report documents the work in two volumes, Volume I, "Emergency and Operational Mine Communications," and Volume II, "Seismic Detection and Location of Isolated Miners." The Tables of Contents of both Volumes are included in each Volume. Phase I of the contract was devoted to performing an in-depth assessment of electromagnetic noise measurements taken by several contractors and other investigators, and then defining a new noise measurement program and instrumentation system tailored to obtain the necessary but missing noise data. These data are required for use in the design of new emergency and operational communication systems. This work, and the follow-on coordination and guidance activities of ADL on this noise measurement program in subsequent phases of the contract, are treated in Part One of Volume I.

Jan 1, 1974

By M. W. Hildyard, M. O. Kataka

Seismic integration schemes aim to incorporate the rock mass response provided by the historical seismic activity to improve the ability of numerical models to reproduce future response to mining. Up to now, integration schemes considered the events using quasi-static models. This paper presents case studies that consider some of the seismic and modelling issues needed to extend these schemes to include the dynamic characteristics of seismic events. The ultimate aim of an automated integration scheme seems impractical for dynamic modelling. The predictions of the WAVE elastodynamic finite difference program are, however, suitable for modelling limited numbers of events to determine either the near-field velocities and damage or the effect of fractures and excavations on the far-field low frequency response. Les projets d’intégration sismique ont le but d’incorporer la réponse de la masse rocheuse à l’activité sismique historique pour améliorer la capacité des modèles numériques à reproduire la réponse future à l’exploitation minière. Jusqu’à présent, les projets d’intégration étudiaient les évènements avec des modèles quasi-statiques. L’étude présente révèle des études de cas qui considèrent certaines des questions concernant modelage et séismes qui sont nécessaires pour porter plus loin ces projets en incluant les caractéristiques dynamiques des évènements sismiques. Le but final d’un projet d’intégration automatisé semble impraticable pour la modélisation dynamique. En revanche, les prédictions du programme élastodynamique par la méthode des différences finies WAVE sont appropriées à la modélisation d’un nombre limité d’évènements de façon à déterminer soit les vitesses à petite échelle et les dommages, soit les effets des fractures et excavations sur la réponse de basse fréquence à grande échelle. Seismische Integrationsschemata zielen darauf ab, Reaktionen der Gesteinsmasse, die von den Berichten seismischer Aktivitäten stammt, zu inkorporieren um numerische Modelle in die Lage zu versetzen, künftige Antwort zum Bergbau zu reproduzieren. Bis dato betrachteten Integrationsschemata die Fälle mit quasi-statischen Modellen. Diese Arbeit stellt Fallstudien dar, die einige der seismischen und modellierenden Fragen betrachten, die benötigt werden, um diese Schemata auszuweiten, um die dynamischen Charakeristika seismischer Fälle einzuschließen. Das Endziel eines automatisierten Integrationschemas erscheint für das dynamisches Berechnen undurchführbar. Die Vorhersagen des WAVE elastodynamisch begrenzten Unterschiedprogramms sind jedoch verwendbar für das Berechnen von begrenzten Anzahlen von Fällen, um entweder die Nahfeldgeschwindigkeiten und Schaden oder den Effekt von Brüchen und Extraktionen auf der Fernfeld Niederfrequenzantwort festzustellen.

Jan 1, 2003

By E. L. Rawlins

The development of commercial natural-gas reserves in the Michigan stray sandstone horizon of central Michigan during the past few years has resulted in expansion of the natural-gas industry in that State. The location of the natural-gas reserves of Michigan in the general vicinity of domestic and industrial markets is of economic importance, and in supplying these markets with natural gas a reasonable knowledge of, the extent and availability of the reserves is needed in formulating regulations for drilling gas wells and producing natural gas in analyzing the feasibility of projects to construct natural-gas transmission lines, in promoting and developing markets for the domestic and industrial consumption of natural gas, and in solving many engineering and economic problems common to the natural-gas industry. The development of the natural-gas industry in Michigan has been related closely to the development of oil production. The potential oil production of Michigan is comparable with that in most of the eastern oil-producing States. The development of oil production probably will continue, especially in the central Michigan Basin area; and as wells are drilled to deep horizons in the search for oil, more knowledge will be obtained of the gas reserves in formations above the oil-bearing horizons.

Jan 1, 1936

By Hermes Vilchéz

El presente texto describe los beneficios de la apertura de los circuitos de flotación como alternativa de mejora en la performance metalúrgica de las concentradoras. El trabajo se efectuó en la empresa minera Los Quenuales, Unidad Iscaycruz (Lima), modificándose los circuitos cerrados a los abiertos y encontrándose los siguientes beneficios: el incremento del tonelaje de tratamiento sin aumentar equipos en los circuitos de flotación, la mejora en la recuperación y el grado de concentrados.

Sep 9, 2007

By W. W. Adams, T. D. Lawrence

"A. larger enrollment and a greater number of man-hours of employment by the enrolled companies were the outstanding features of the National Safety Competition of 1942, an annual safety contest conducted by the Bureau of Mines, United States Department of the Interior, for the promotion of safety among workers in the mines and quarries of the United States. The accident-frequency and accident-severity rates were somewhat higher than in 1941, but the frequency of accidents in relation to the number of man-hours worked was strikingly lower than in the earlier years of the 18-year period during which the contests have been conducted.Companies that enroll in the National Safety Competition compete for a bronze trophy known as the ""Sentinels of Safety."" Six of these trophies are provided by THE EXPLOSIVES ENGINEER annually for award by the Bureau of Mines. The trophies for 1942 wore won by an anthracite mine in Pennsylvania, a lignite mine in North Dakota, an underground metal mine in Tennessee, a limestone mine in Ohio, an open-cut metal mine in Minnesota, and a lime-:tone quarry in Pennsylvania. The trophies are presented to the companies for 1 year and are then transferred to the winners of the succeeding year's contest.The contest rules state that a mine or quarry must have at least 25 men employed underground or in the pit for at least 100 days, and the plant must be in operation 30,000 or more man-hours to be eligible for a trophy. The rank of mines and quarries is determined by accident-severity rates, or, in the case of accident-free records, by the number of man-hours worked."

Oct 1, 1943

By B. G. H. Thomas, W. P. Yant, A. C. Fieldner, R. R. Sayers, W. J. McConnell

"One of the outstanding problems confronting automotive engineers in attempting to construct motors of greater economy is that of eliminating the ""knock"" from the operation of the engine. Recent investigations of this detonation or knock in internal-combustion engines, especially of the high-compression type, have demonstrated that it can be eliminated or reduced by decreasing the reaction velocity of combustion by adding small quantities of certain compounds to the gasoline, This makes it possible to use engines of a higher compression ratio, thereby greatly increasing the mileage per gallon of gasoline consumed. The savings in fuel reserves from increasing the proportion of crude oil marketable as motor fuel and in permitting the designing of more efficient engines are obvious.Ethyl gasoline, one of the widely used anti-knock fuels, is ordinary motor gasoline to which has been added 3 c.c. of tetraethyl lead and 2 c.c. of a halogen carrier, as ethylene dibromide or trichiorethylene, or approximately 0.06 per cent of the lead compound and 0.04 per cent of ethylene dibromide by volume. Ethyl gasoline should not be confused with ethyl fluid, which is a mixture of concentrated tetraethyl lead and ethylene dibromide in the prowler proportions for mixing with gasoline, but is not a motor fuel and is not sold to the public. Also tetraethyl lead is not a motor fuel, and likewise is act sold to the public."

Dec 1, 1924

By D A. McCallum

With depth, many gold ores become sulfidic with minerals such as pyrite, pyrrhotite and arsenopyrite becoming prevalent. In addition, many underground gold mines use tailings backfill to bind and store the waste. In these cases, acid mine drainage (AMD) can become an issue. One approach to the control of AMD is desulfurisation whereby the sulfide minerals are removed prior to disposal. Four sulfide tailings samples, representing different ore types and gold and base metal operations, were selected for assessment and testing using simple physical beneficiation techniques. The aim was to determine the extent to which mineral processing methods were suitable for separating sulfides from non-sulfides and for extracting potentially marketable by-products from the tailings. In order to streamline the testing procedure a simple diagnostic separation technique was developed to enable quick screening of bulk sulfide tailings for suitability for reprocessing. The testing procedure involved detailed characterisation and a sequential set of testing regimes based on simple unit processes including water washing, classification, gravity concentration, magnetic separation and bulk flotation. The preliminary test results indicate each unit process can play an important part in producing effective sulfide/non-sulfide separations and in generating useful by-products from the tailings. Potential valuable products identified include coarse, benign silica sands, bulk iron sulfide products rich in pyrite and/or pyrrhotite, high-grade iron products (magnetite) low in silica, low-volume bulk sulfide concentrates and low-grade molybdenite and talc products. The work presented shows how sulfide tailings can be viewed as a resource rather than a waste stream, and identifies a pathway for developing a more sustainable approach to the environmental management of sulfide tailings for the future.

Jan 1, 2007

By K. C. McMahon

This report is the result of the engineering efforts performed by the Mining Equipment Operations of FMC to develop methods of automating a continuous miner. This work was done as part of modification number three of the contract for the development of a miner/bolter system. As the demand for energy places an ever-increasing pressure on the coal mining industry to produce more coal, methods for underground mining which will increase productivity with a con-current increase in safety are being actively sought. Removing the machine operator from his station on the continuous miner and placing him at a safer location behind the machine while retaining his control functions via an umbilical cable or a radio link was an important first step. However, the problems of poor visibility, no control "feel", and the judgmental problems of controlling the sump distance and the shear limits have not been conducive to the productivity increase that is desired.

Jan 1, 1975

By Eugene A. Dolecki

This final report describes the work accomplished under U.S. Bureau of Mines Contract #H0242011 - "Feasibility of Automated Rail Haulage Systems in Underground Coal Mines." The report outlines the base for the development and evaluation of automated rail haulage systems in terms of the service requirements for haulage systems in underground coal mines, and of the performance of existing haulage systems. A generalized automated rail haulage system concept is defined. A safety impact analysis of automating the mainline portion of the underground system indicates a 50% reduction in injuries and fatalities. A cost effectiveness (over the total life cycle) study for the system indicates a cost benefit can be obtained from implementing an automated rail system. The design specifications for the total automated rail haulage system - including subsystems and components -are developed, and the equipment types and general design approaches evaluated, with selections outlined. A detailed conceptual design for a prototype automated system is described. Conclusions and recommendations are presented, and a program plan devised for implementing a proto-type automated rail haulage system demonstration in an operating underground coal mine by 1980.

Jan 1, 1976