Search Documents

By G G. Suffel

T HESE remarks on the occurrence of strata-bound massive sulphide deposits are submitted be-cause the writer recently visited the principal Cyprus deposits (in January, 1965) and has also a back-ground of many years spent largely in detailed observation and map-ping of the Horne and Amulet ore-bodies, now largely inaccessible. They are particularly related to the Symposium papers (September Bulletin) by Hutchinson and by Roscoe. Some comments are offered on the cupriferous pyrite deposits of Cyprus. As the writer is currently reviewing the published literature on the related deposits in Turkey, a brief account of some characteristic Anatolian sulphide occurrences is given. The discussion is closed with some thoughts on the relationship between these Mediterranean sulphide deposits and those of northwestern Quebec and the Superior province in general. The geology of Cyprus, as it relates to the sulphide deposits, is well summarized by Hutchinson (1965). After visiting Mavrovouni, Skouriotissa and Limni and after much thought on the possible ge-nesis of these ores, it seems quite logical to me that he is right. They are indeed closely related to late-stage submarine volcanism.

Jan 1, 1965

By Paul F. Ziemkiewicz, Aaron Noble, Christopher R. Vass

Many modern industries rely on rare earth elements (REEs) to produce products that are essential to both civil and defense applications. In a prior study (Vass et al., 2019), the authors showed that REE grades in acid mine drainage (AMD) and associated byproduct precipitates from AMD treatment (AMDp) warrant evaluation as a feedstock for REE production. The current work extends that effort through a broad survey of 141 AMD treatment sites in Northern and Central Appalachia. In this study, 185 raw AMD and 623 AMDp field samples were obtained and analyzed to assess the REE and major metal concentrations. Results show that an average of 282 μg/L and 724 g/tonne of REEs occur in AMD and AMDp respectively. Additionally, both basins contained similar distributions of REEs, and these distributions tended to favor heavy and critical REEs when compared with traditional REE ore deposits. Geospatial analysis identified a total resource of 340 tonnes stored at the 141 sites sampled in this study. While this analysis did not quantify the basin-wide REE inventory, it does indicate the impact that processing cut-off grades will have on the overall AMDp resource base.

By Scott A. Howard

MgO is routinely used as the basis for refractory materials, however, its susceptibility to hydration may result in dimensional instability and subsequent failure. The addition of boron has been shown to reduce th,e hydration susceptibility of MgO yet its dissolution into certain grades of steel may degrade their performance. In order to predict the efficacy of reducing hydration susceptibility by the incorporation of mono-, di-and tri-and quadravalent cations, the lattices of various cation-substituted systems were modeled. To more accurately simulate the substituted lattices, either cation or anion vacancies were incorporated to maintain electrical neutrality and all possible arrangements of defects in a 2x2x2 MgO supercell were investigated. Correlations were then made between the lattice energies of these systems and their susceptibility to hydration as reported in the literature. The results indicate the presence of higher charged cations tended to increase lattice stability while the cations with lower valency tended to have lower lattice energies. The relatively small body of experimental results available in the literature are consistent' with this study's results.

Jan 1, 1989

By Florence L. Feicht, Carlton E. Brown

"INTRODUCTION This report contains information on the approximate size of the smallest dust Particles revealed by or the limit of visibility of various microscopic systems. The information was obtained mainly for use in interpreting and evaluating results of number-contentration and particle-size, determinations on, samples of unhygienic particulate matter collected from industrial atmospheres and in developing better methods for determinations nations.Some speculation and even controversy have been published on the limit of visibility of the widely used microscopic system (16-mm., 0.25-or 0.3-N.A. objective, and axial light-field illumination) used in counting the dust in the liquid medium from impinger, 4/ 5/ filter-paper, 6/ and other samples, but little or no quantitative data have been published on the limits of visibility of this or other microscopic' system.ACKNOWLEDGMENTSThe interest, encouragement, and assistance received from H. H. Schrenk, chief of the Health Division are gratefully acknowledged, as is all other assistance received in this study."

Aug 1, 1945

By David A. Newman

The Geomechanics Classification (Bieniawski, 1979) was modified for entry and roof support design in underground room-and-pillar coal mines. Adjustment multipliers were introduced to incorporate the influence of strata weatherability, high horizontal stresses, and the roof support reinforcement factor into the existing classification system. Sixty-two case histories of both standing and fallen mine roof were collected from two mines in the northern Appalachian coalfield. Twenty-seven engineering and geologic parameters were recorded for each case. A partial correlation analysis was carried out on the cases to establish which parameters have a significant impact upon the supported stand-up time of coal mine roof. Survival analysis, a statistical technique used in medical research to assess the effect of a drug or treatment on a patient's life expectancy, was conducted together with stepwise multiple regression to derive values for the adjustment multipliers. A practical example is included to illustrate the application of the modified Geomechanics Classification to underground coal mine design.

Jan 1, 1985

By Chao Zhang, Wenhao Xia, Jianxin Fu, Ling Yu, Weidong Song, Yang Li

Sanshandao Gold Mine is the only undersea metal mine in China. To deal with the collapse and pumping of stopes and roadways caused by complex ore-rock occurrence conditions, the mine conducts filling and sealing of some areas, and the remaining ore reserves will be mined after treatment. Therefore, it is urgent to evaluate the stability of rock masses, fault fracture zones, and aquicludes during the secondary mining process. In this study, displacement and microseismic methods are employed to monitor rock deformation and fractures. Additionally, FLAC3D was used to simulate the process of secondary mining, reproducing the evolution of stress fields, displacement fields, seepage fields, and plastic zones at different mining stages. The combination of numerical simulation and on-site monitoring verification demonstrates that the deformation of surrounding rock presents a rapid growth at the initial stage of mining, followed by a gradual decrease in the growth rate, and finally tends to stabilize; the fracture zone area at the 151–159 exploration line on the − 320 m level (near the 7# and 8# stopes) exhibits poor stability, and monitoring measures should be strengthened; the deformation value of the aquiclude is less than the deformation value of I protection level in the Code for Design, the impact of secondary mining on the aquiclude is limited; fault and fracture zone deteriorate rock mass stability, and their impact is related to their spatial locations. Hanging wall fault has a more significant impact on the settlement of the aquiclude, while the footwall fracture zone has a greater impact on the development of the plastic zone.

Feb 21, 2024

By M Lovitt, T Hewitt

The extraction of drawbells in Lift #2 at Northparkes Mines E26 orebody was achieved by single shot blasting, enabled through the use of electronic detonators. This paper discusses the designs considered at the time of the feasibility study and the various changes made to these designs prior to and during the construction phase of the Lift #2 block cave. Operational issues encountered are highlighted, as are ways in which these were overcome. The amount of personnel utilised to mine the drawbells is also covered. Lists of design and operational considerations to be used for drawbell extractions have been included.

Jan 1, 2005

By A Kleinitz, J Halilovic, K Trappitt

Mine operators use grade control to determine the destination of each block of material in the mine. In polymetallic mines, grades are best expressed in dollars: the Net Smelter Return, NSR, per tonne. To estimate NSRs, geologists working on grade control develop models for each geometallurgical domain in the mine. These models may incorporate observations on the mineralogy and grain sizes of the material being examined. The site’s mill operators contribute to the models by providing geologists with statistical analyses that relate assay results and mineralogical compositions to metallurgical parameters, such as the rates of recovery of each economic metal to each of the concentrates produced, and the compositions of those concentrates. The team responsible for sales and marketing of the site’s products contributes to the NSR models by providing details of the costs of shipping concentrates to smelters and refineries; and by providing figures that are specified in the smelter contracts, such as the payability of the metals in each concentrate and the fees charged by the smelter. The mill operators also provide, for the NSR models, equations to estimate the rates of recovery of deleterious materials to each concentrate. Deleterious materials comprise mostly halogens and amphoteric elements, both of which reduce the efficiency of smelters. Furthermore, deleterious materials such as antimony and arsenic may be poisonous to people and to the environment. The sales and marketing team provide specifics of the penalties that smelters impose upon deleterious materials. These penalties may reduce NSRs by tens of percent, possibly to levels below the cut-off grade. Thus, in the blocks that are subject to grade control, mine geologists monitor not only the concentrations of economic metals, but also the presence and abundance of deleterious materials. The preparation and maintenance of models, to estimate NSRs and to assess changes in the levels of potentially toxic materials to be mined, requires close and continuing consultation between corporate departments. There must be strong communication of mine geologists with the mill operators; with the people who market the mine’s concentrates; and, should there be a risk of encountering toxic levels of deleterious materials, with the mine’s health, safety and environmental officers. This co-operation could require radical changes in the structure of many organisations. However, experience suggests that such changes can significantly improve the profitability of a mine.

Mar 22, 2022

By D. Harrington, W. J. Fene

For nearly 30 years the Bureau of Mines has contended that mine explosions can be prevented and has pointed out to the industry ways and means by which they could be avoided. The record of co2l-mine explosions • during the past fiscal ?Bar bears out the :Bureau1s contention, inasmuch as fewer men were killed by coal-mi~e e:xplosions in the United States during that year than in :gi_y corresponding 12 months in the history of coal mining in the United States, insofar as records are available; and more than a year has elapsed since·a major explosion (in which five or more men were killed) has occurred, this being t.1-J.e first continuous 12- month period without a major coal-mine explosion disaster in the United States in more than 60 years. The methods of preventing mine e:iiplosions are well known to experienced, well-informed persons cngnged in coal mining. Despite this knowledge, many coal-mine operutors continue to use practices and methods that they should know have resulted in countless explosions, and mine workers persist in following past procedure or in breaking safety rules and practices almost certain eventually to result in disaster. ' Virtually all explosions are the result of human failure, such as carelessness or neglect by officials or workers or others. These human failures can be corrected chiefly by ed.ucation and proper and adequate supervision and strict discipline. In some instances mine officials are ·lax, careless, poorl~• informed, and often incompetent; end in many instances miners have repulsed the introduction of known preventive methods because of sheer obstinacy, ignorance, heedlessness, or possibly fear that the operator was trying to o'bta.in some unfair adva.,.'1. tago or would neglect some other phase of accident or e,:plosion prevention. The freedom of the fiscal year 1938-39 from major coal-mine explosions ar..d frora any considera~le number of fat,JJ.i ties from minor explosions is a. matter for congratulation, but on the other hand. the occurrence of one rather bad e~losion in each of tho 3 calendar years 1937

Nov 1, 1939

By Charles W. Daugherty, Eugene B. Waggoner

In the construction of recent subsurface projects, particularly mined openings and transit systems, it has been apparent that final costs were often greater than first expected. Because many overruns result from alleged differing site conditions, there was reason to suspect that pre-bid geotechnical investigations were inadequate for predicting subsurface geology. In 1982, nine federal agencies involved in constructing underground facilities funded the National Academy of Sciences' U.S. National Committee on Tunneling Technology (USNC/TT) in an effort to evaluate and clarify the relationship between geological knowledge and construction costs. That committee formed the special Subcommittee on Geological Site Investigations, which spent more than two years studying underground projects by examining contract documents and geologic reports, making site visits, and interviewing owners, designers and contractors. The study ultimately encompassed 84 mined tunnels and chambers and three deep shafts in the United States and eastern Canada. Data collected on geologic exploration, design and construction were analyzed and conclusions reached concerning whether and how site investigations need to be improved. The results of the study are published in two volumes by the National Academy of Sciences. Due to the recent completion date of the main report, it was not possible to prepare a summary for inclusion in the RETC Proceedings. However, the complete two-volume report, "Geotechnical Site Investigations for Underground Projects," can be obtained by writing or calling: U.S. National Committee on Tunneling Technology National Academy of Sciences 2101 Constitution Avenue, N.W. Washington, D.C. 20418 (202) 334-3136

Jan 1, 1985

By Frederick G. Coqueron, Joseph E. Pogue

FOR a number of years, the Department of Petroleum Economics of The Chase National Bank has been conducting a study of the capital employed in the petroleum industry. The technique followed is that of combining and summarizing the available financial and operating data for a group of thirty representative oil companies, doing about two thirds of the domestic business of the entire industry. This paper presents the results of the findings for the year 1943, and supplements the survey, "Sources, Disposition, and Characteristics of the Capital Employed by Thirty Oil Companies During the Nine-Year Period, 1934-1942," presented before the Petroleum Division of the American Institute of Mining and Metallurgical Engineers on Feb. 24, 1944, and also published as a pamphlet by The Chase National Bank.

Jan 1, 1944

By V. E. Housman

EPA's Mining Waste Section within the Office of Solid Waste is continuing to collect and analyze information on mining waste management practices. Starting in 1991, the Mining Waste Section has continued to conduct site visits and prepare case study reports on the waste generation and management practices of operating mines. In choosing sites to study, a reasonable attempt was made to provide diversity in mining commodity types, geographic regions, geology, climate, and environment. To date, EPA has visited the following mines: Asarco Troy (copper) in Montana, Newmont Rain in Nevada (gold), Cyprus Thompson Creek (molybdenum) in Idaho, LTV Steel (iron) in Minnesota, Phelps Dodge Morenci (copper) in Arizona, Doe Run Fletcher (lead) in Missouri, Brewer (gold) in South Carolina, IMC Four Corners (phosphate) .in Florida, Pennzoil Culberson (sulfur) in Texas, Nerco Cripple Creek (gold) in Colorado, Copper Range White Pine (copper) in Michigan, Magma San Manuel (copper) in Arizona, Colosseum (gold) in California, and several gold placer mines in Alaska, including the Valdez Creek Mine. EPA has prepared a case study report on each facility. The mine operators were provided an opportunity to comment on their respective site visit report and their comments have been included in' each respective report. These site visit reports have in turn been incorporated into technical resource documents which provide a detailed description of each mining sector. EPA is currently reviewing the technical resource documents and plans to release the documents in the Spring of 1994.

Jan 1, 1994

By Russell G. Slayback

An integral part of site investigations for shafts and underground workings should be hydrogeologic evaluations of the need for and method of ground-water control. Such investigations should include: 1. Classification of the problem by aquifer type. 2. Integration of other site investigations with hydrogeologic programs, including assessment of the need for water control. 3. Planning and conduct of aquifer tests tailored to the aquifer situation. 4. Evaluation of pumping requirements to achieve water control objectives. 5. Scheduling of dewatering for optimum results and costs. 6. Evaluation of environmental impacts of pumpage and water discharge. 7. Planning of operational monitoring for program modification and liability limitation. Early hydrogeologic involvement can result in avoiding unnecessary duplication in site investigations.

Jan 1, 1981

By J L. Kerr, J Beyer-Robson, S Vink

Driven by an increasing need for water conservation, coal mine operators in the upper Isaac River catchment have placed significant emphasis upon the reuse of water. This initiative led to an overall increase in the salinity of mine waters. The ionic composition of this water differs from local stream water in that concentrations of sulfate are higher than average stream concentrations by ten per cent, while concentrations of bicarbonate and calcium are lower. When this water is discharged into ephemeral streams in semi-arid environments there is potential for this increased salinity and altered ionic composition to impact upon the ecosystem processes mediated by micro-organisms in river sediments.We have measured nitrification, denitrification and methanogenesis rates in a series of lab experiments using sediments from Isaac River catchment streams and found that salinity affects these processes in different ways and to different degrees. Process rates were shown to differ seasonally between samples taken from the same location and habitat type and also between different habitat types at the same time and location. Both aerobic and anaerobic process rates were higher in surface sediments and it is likely that this activity is associated with surface biofilms. Furthermore, we have shown that the ecosystem processes we have measured are limited by the availability of carbon in the sediments.The management implications of these findings for mine releases into ephemeral streams will be discussed.CITATION:Kerr, J L, Vink, S and Beyer-Robson, J, 2013. The effects of increased salinity on microbially mediated ecosystem processes in ephemeral streams, in Proceedings Water in Mining 2013 , pp 121-134 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By C. H. Johnson

The Big Jim mine of the United Eastern Mining Co. is at Oatman, Mohave County, Ariz. Oatman is in the foothills on the western side of the Black Mountains, at an elevation of about 3,000 feet. It is on a paved highway about 30 miles west of Kingman, the principal distributing; center for mining supplies in the district, and 25 miles from Topock, en the Colorado River. Both latter towns are stations on the Santa Fe Railroad; Oatman has no roil connection. Mining conditions are typical of western Arizona; water is scarce, no mine timber is available locally, and the winters arc mild and the summers hot. The supply of a killed labor is usually adequate, but in 1933-34 it w not more than sufficient for the restricted operations. Wages have been $4.00 to $4.50 for miners. Electric power was supplied from Kingman and cost about 2.6 cents per kilowatt-hour.

Jan 1, 1935

By M. Lghoul

Acid mine drainage (AMD) remains one of the major environmental problems for the mining industry particularly for many abandoned mine sites. The production of AMD as is commonly known can significantly affect the surrounding groundwater and surface water of the mine site. With the objective to investigate the impact of the AMD produced at the abandoned Kettara mine site (Morocco), groundwater sampling campaign was performed at this site. The sampled waters were analyzed to determine the hydrogeochemical composition, and then results were analyzed using different studied methods such as multivariate statistical analysis and geochemical modeling techniques. Investigation results show that the hydrochemistry of sampled waters is characterized by the relatively significant enrichment of Ca2+, Mg2+ and SO4 2-. The typical mine waters belong to the (Ca2+ +Mg2+)-SO4 2-type. Seasonal variations in major ion concentrations were partly attributed to dissolution/ precipitation processes. The saturation index (SI) calculation of the representative dissolved minerals in waters show that groundwater samples are undersaturated with respect to most potential sulphated secondary minerals.

Aug 1, 2013

By Tom H. W. Loomis

The department of the Interior is a federation or holding company of several fiercely independent bureaus which have either jurisdiction or expertise - or both - in a wide range of environmental fields. Each bureau is an advocate for its own concerns and an enforcer of its own mandates. This can be confusing to the company operating in the field. I will try to explain our concerns, help you see where we are "coming from," and give you some insight as to how we can help you. Other speakers have stressed the environmental concerns and site selection factors for uranium wastes so I will focus on the concerns of the Department of the Interior and some of the assistance we can give you in this area People are more aware and more concerned about environmental factors now than they used to be. Thus the past decade has brought about an evolution in both siting and design of uranium mill tailings ponds. Site selection criteria used to be simple - find a tract of land as near to the ore supply as possible with enough space and suitable topography for the expected volume of wastes. Site selections in the past have left a legacy of problems to be corrected - radioactive wastes on stream banks and in floodplains, mill wastes in and near established communities, and unprotected wastes subject to constant erosion. This is no longer acceptable environmentally or socially to a newly aware and concerned public. (Series of 30-35 slides showing uranium mine and mill wastes in Western United States. These illustrate environmental problems, reclamation and environmentally acceptable sites. The first group of slides are aerial shots taken in Wyoming and shows a surface mine and mill area. In the various views the pit, overburden piles, mill, and tailings pond can be seen. The next series were taken in Wyoming and New Mexico. These show various views

Jan 1, 1980

By B. R. Broekman, D. W. Penman

Discussion by P.J Lloydt Broekman and Penman describe (J.S. Afr. Inst. Min. Metal., vol. 91, Aug. 1991, p. 261) the addition of sodium cyanide and zinc sulphate to the flotation feed at Prieska. They note that for 'safety sake, lime was added to the rod mil to raise the pH to 9,5', and that 'personnel working in the vicinity of the rod mil were required to wear gas masks'. Author reply to P.J. Lloyd We thank Dr Lloyd for his interesting contribution. As he correctly points out, the Prieska float had run with cyanide solutions at pH values of 6,4. In fact, it ran safely for extended period with the pH slightly below 6.

Jan 1, 1991

By C. Harry Benedict

This paper, describing the leaching practice at the Calumet and Hecla mills, Lake Linden, Mich., is one of a series on milling methods and costs being published by the United States Bureau of Mines. GENERAL DESCRIPTION The reclamation plant is located along the shores of Torch Lake at a slightly lower level than the concentrator itself. The entire location of the original concentrator, in connection with the present reclamation plant, has been ideal, lore particularly as the leaching and flotation departments are common to both units. After 15 years of operation and with the reclamation sands just a little more than half exhausted it would appear that the remaining life of the deposit could be worked by the present plan, without decided changes or renewals of plant or equipment.

Jan 1, 1930

By Ludwig Schmidt

The attention of operators of oil-producing properties long has been directed toward methods of' disposing of petroleum wastes as well as the disposal of oil-field brines. The problem of disposing of' petroleum wastes is not easy to solve, and although many operators are to be commended for the efforts they have made, much work remains to be done before the problem can be considered solved. Petroleum wastes include emulsions of petroleum and brine or mixtures of petroleum and sand that cannot be "broken down" or treated economically by known methods of separating petroleum from deleterious matter; crude petroleum that escapes from pipe lines, fittings, and tanks because of holes in the lines, leaky connections, or some accident; and oil-saturated materials that accumulate accidentally or otherwise an the normal operation of an oil-producing property.

Jan 1, 1938