Search Documents

By S. Partney

Waste clay ponds are a necessary part of the phosphate rock beneficiation process. They are large, averaging a square mile in size; unsightly, in that they protrude 20 to 50 feet (6 -15 meters) above natural grade; stabilization and reclamation is slow; and they have had a history of catastrophic failure. The State of Florida has never published a specific rule regarding the configuration or height of these ponds, but has enforced numerous policies along these lines. The current rules are given and interpreted, along with the reasoning for current policy. In addition, an overview of the history of the policies, and an attempt at explaining the reasons for the changes that have occurred is given. The industry has been forced to make major monetary decisions, having effect for decades on mine economics, in a constantly changing regulatory environment. The Bureau of Mine Reclamation is confident that a direction of regulation has been solidified, but changes are still to be anticipated.

Jan 1, 1998

By S. Stebbins

In 1994 Western Mine Engineering, Inc., (WME), which is now InfoMine USA, Inc., set out to build a suite of stand-alone software programs that would provide their clients the means to estimate the costs of developing and operating mineral exploitation projects. After the first program (Sherpa for Surface Mines) was completed and launched, the developer (me) left WME to form Aventurine Engineering, Inc., in order to complete the series of applications. In the years since, four programs have either been developed or upgraded and enhanced. Applications were produced that estimate the costs of underground mining, placer mining, and project site reclamation. In addition, an application specifically designed to evaluate the economics of these projects, which was based upon a program previously developed for WME by Bill Willoughby of Willoughby & Associates, was redesigned and the code updated to a MicroSoft compatible platform. All these programs follow an engineering-based approach to cost estimating. Instead of relying on rules-of-thumb and statistical averages, they calculate all of the engineering and operational parameters needed to estimate costs. The premise is that the uncertainty associated with cost estimates should lie with the data available for the resource, not the approaches used to design and estimate the associated design parameters. In other words, it is acceptable that items such as the resource grades, deposit dimensions, ore and wall rock characteristics, and mill recovery rates carry with them some uncertainty, but parameters such as loader bucket capacities, truck speeds, pump horsepowers, hoist velocities, and grinding mill diameters can be calculated (although uncertain data might be used in those calculations). No additional uncertainties should be introduced because the cost-estimating procedure relied upon statistical manipulation or anecdotal inaccuracies. To that end, the programs rely upon calculation-based approaches to selecting and sizing machinery, assigning the required workforce, and determining the extent of the consumables needed to recover mineralized material at a rate defined by the client. And while calculation-based software is not unusual, more modern approaches work toward the development, accumulation, and manipulation of data. INITIAL CONDITIONS AND PROJECT GOALS In 2016 we had five separate programs completely disconnected from one another. Each was written in VisualBasic, a language that was falling from favor. In essence, the status in 2016 was a series of stand-alone programs (Figure 1) in which results from one needed to be manually entered as input into another.

Jan 1, 2019

By Earl A. Berry

Someone once said, "The safest mine is one in which no one goes into." We all recognize this as being perhaps wishful thinking. We also recognize in it a certain amount of truth and an ultimate goal if we are optimistic. All of us are aware of the many things that have been done, are being done and will be done to reduce manpower in mining. For those of us; who are optimistic about this ultimate goal it would appear from the records-we are more than well on our way to the so called safest mine. Let us see what has been done in the past 20 years. T e period from 1935 to 1956. For example in the coal mining industry: In 1935 there were employed 462,903 men who produced an average of 805 tons per man per year or 4.50 tons per man per day. In 1955 there were employed 225,093 men who produced an average of 2,064 tons per man per year or 9.84 tons per man per day. There are no comparable figures compiled for the metal mining industry as a whole that can be broken down in this manner. However, from examination of figures available for different groups in metal mining there is a trend similar to that in coal mining. No-dbout the above figures reflect the intense development and perfection of machines and mining systems to tear out, transport and process our mineral wealth. The figures also show the mining industry has been able to double its production and at the same time reduce its manpower by half. When you compare the number of men employed today with the number which would have been employed 20 years ago to gain todays production at that time it become apparent that greater safety has been accomplished. For example the years 1935 to 1956 for all mining show. In 1935 there were approximately 649,226 men employed in mining and reports show 1,399 fatalities and 74,913 non-fatal injuries. In 1955 when there were 313,883 men employed in mining 496 fatalities and 25,365 non-fatal injuries were reported. To have produced the same tonnage of material in 1935 that was produced in 1955 it would have required the employment of approximately 1,298,452 men. 2,798 could have been fatalities and 149,826 could have had non-fatal injuries. You can now measure the full impact of what has been accomplished in the past 2o years by the aggressiveness of mine management, the wizardry of our engineering personnel and the thoughtfulness and devotion of our safety people and their programs. Therefore, there is a trend towards the goal of our opening statement. We whoare toptimistic believe this trend will accelerate at a-faster pace. Why? Because anyone engaged in the mining industry today can well afford to invest a minimum of $30,000.00 in capital equipment todisplace the labor of one man. This fact alone is a terrific incentive for mine management to apply and manufacturers to develop equipment of a type to get the men out of the mine. Now you can determine this problem not only becomes one of safety but also one of economics, When productivity is stepped up and manpower reduced management is learning the hard way what it means to them; in the profit and los s column when a few minutes of delay or downtime of costly machines and processes occur. They have learned that fast and efficient communication systems are the best means of combating breakdown, delays, bottlenecks, supply problems, the saving of lives and property and increasing production. One large western metal mine was able to increase Its tonnage by 4000 tons a day by using modernup to date electronic type communication system. The National Coal Board of Great Britain recently allocated 45,000,000.00 to study and develop faster and more efficient communications when a survey indicated what a serious bottleneck poor communication in their present systems of mining turned' out Lobe.

Jan 1, 1958

By James Westfield

I welcome this opportunity to appear before you and to review briefly the various health and safety services of the Bureau of Mines available to the mining industry, other than coal, and also to tell of our plans for extending these services to improve safety and health conditions. The Bureau's health and safety activities are basically services by which we attempt to develop and disseminate information on improved techniques in mine accident prevention and promote mine safety education in the mineral industries. Unfortunately, some mining companies, particularly some of the smaller operations, seem to be unfamiliar with these services, The Bureau of Mines is charged by law with the responsibility for inspecting coal mines; other services to the coal mining industry and are provided only on request, Safety inspections and other services that we offer are provided for noncoal mining industries solely upon request.

Jan 1, 1958

By Richard J. Wilson

The importance of coal as a major source of energy used by the steel industry has been increasing due to the gradual changeover from steel- making by the open hearth process to steelmaking by the basic oxygen process. Since the production of steel by the BOF process increases the demand for hot metal, there is a growing need to ensure the supply of coke required for the production of hot metal. Coal used for cokemaking has become, therefore, an increasingly important raw material for the steel industry in recent years. Our current projections indicate that coal will be the source of 71% of the total energy requirements of Inland Steel Company in 1985. As a result of the energy shortages of the last few years, various conservation programs have been initiated by the steel industry to reduce the consumption rate of fuel. The efforts to conserve energy have been successful to a great extent due to the rapid advances made in the technology of ironmaking that facilitated gradual reductions in the quantity of coke used per ton of hot metal produced in the blast furnaces. The decrease in the consumption rate of coke was made possible by the use of improved raw materials, such as iron ore pellets and fluxed agglomerates, the operation with high blast temperatures, the injection of auxiliary fuels, and the enrichment of the blast with oxygen. It is expected that additional reductions in the fuel consumption rate will be possible in the ironmaking operations of the large blast furnaces that are being equipped with facilities for proper burden distribution and for operation with higher blast temperatures at high top pressure. The purpose of this paper is to show the effects of coke quality on the production of BOF steel. The importance of coke quality will be pointed out by discussing the effects of the physical strength of coke on both the blast furnace productivity and the steelmaking operations of an integrated steel plant, such as Inland Stee1 Company.

Jan 1, 1980

By H. B. Comstock

This paper reviews the trends in supply and consumption of the principal magnesium compounds in the United States in relation to domestic requirements and world resources. The data are confined to these principal magnesium compounds: Magnesium chloride, magnesium hydroxide, precipitated magnesium carbonate, and magnesium oxide (commonly referred to as magnesia). The properties and uses of magnesium compounds are shown in various chapters of' the 2nd edition of Industrial Minerals end Rocks. 3/ The third edition of this reference is in preparation. A more recent description of properties, uses and sources of magnesium compounds appears in a Bureau of Mines publication.4/ The American Iron and Steel Institute and the Refractories Institute have published comprehensive data on the properties and uses of basic refractories. Many magnesium compounds are prepared by the producers to meet specifications set by individual consumers.

Jan 1, 1960

By C. Leal

Modern production has as goal to reach high and uniform quality in their products. To success with this, it is essential to have a good knowledge of the different variables involved in the process. Investigation or analysis of a process or system has as references the measurements of the variables. These measurements are presented normally in form of data. These data are measured in intervals over time. The aim with measurement of the data in a process is to obtain information about the state of it in order to have it under control. Other goal is to know how the results are affected by the process variables to improve upon product quality, redunding manufacturing cost, better pollution control etc.

Jan 1, 1994

By S. Kemball-Cook, D. Heinze, A. Kornberg, M. Harmon

Climate change presents risks to mine infrastructure, operations and long-term obligations to protect environmental conditions. Management strategies and design of infrastructure and containment systems based on past or current climate conditions may be inadequate in the future if changes in climate are not taken into account in planning for mine operations, decommissioning, closure and post-closure. Data-driven assessments using climate model projections of the future can be used to quantify: • Changes in site-specific risks to mine structures, access, containment facilities, operations and staff safety. • Changes in vegetation and water balance/chemistry, and potential for acid mine drainage, erosion and design failure. Climate- and weather-related risks are a serious threat to the mining industry, but risk transfer solutions can alleviate these vulnerabilities. Mining companies can protect themselves through bespoke solutions which provide operators, investors and buyers with protection against weather-related disruptions to operations by hedging to smooth revenues. Using risk transfer structures to mitigate climate risks is a mechanism that is available to all types of mining operations world-wide. In this paper, we describe methods for evaluating site-specific climate change impacts and developing risk transfer solutions to mitigate their effects. EVALUATING MINE RISKS FROM CLIMATE CHANGE The best available tool for understanding potential future changes to the earth’s climate system are global climate models (GCMs) (IPCC, 2014). GCMs are computer simulations of the climate system which include the atmosphere, ocean, land surface, cryosphere and biosphere. Because of the computational demands of running a global model for many decades, the spatial resolutions of the GCM grids are necessarily coarse, typically on the order of 100-300 km. GCM data are therefore suitable for evaluating future physical risks on global or continental scales, but may not be appropriate for evaluating location-specific risks (e.g. Kotamarthi et al., 2016). For site-specific, quantitative physical risk assessment, GCM projection data are “downscaled” or adapted for use at the local level using statistical techniques together with observed data (statistical downscaling) or using high-resolution regional climate models (RCMs) that focus on a single geographic region and have spatial resolutions of 10-50 km (dynamical downscaling). Downscaling bridges the gap between the GCM scale and regional/local scale. Through the downscaling process, new information is added to the GCM output from observations and/or RCMs, resulting in patterns for weather variables that are more consistent with local terrain and weather influences. Downscaled climate change projections for the mine site are selected considering mine location and geography, the availability of local observations, and the performance of the downscaling method and global/regional models used to develop the projection in simulating the variable under study. Where possible, we use projections from an ensemble of global and regional model runs spanning a range of future greenhouse gas (GHG) scenarios.

Jan 1, 2019

By James J. Fallon

Last summer Larry Miller of Roberts & Schaefer told me that his AIME committee would like me to present some thoughts on the marketing of industrial mineral fillers and pigments to this illustrious group in Las Vegas. Shortly after, Brian Coupe of "Industrial Minerals" (the magazine) notified me that I would be presenting a paper to the Fourth International Industrial Minerals Congress in Atlanta this June. It seems to me now it might have been more appropriate to reverse the papers. Las Vegas, a town based on risk, might want to hear what we have to say in Atlanta. The subject for June is "Risk Philosophies of U. S. Industrial Minerals Companies". However, upon reflection, marketing of industrial minerals reflects risk philosophies to a considerable extent, so we'll cut the deck and deal on the subject of marketing.

Jan 1, 1980

By R. S. Austin

One third of the world's and most US kaolin is produced from Late Cretaceous and Early Tertiary sedimentary strata in Georgia and South Carolina. The kaolin is part of a belt extending to Arkansas of aluminous lateritic deposits, including bauxite. Original sediments were profoundly altered by chemical weathering during Early Tertiary time. Mining exploits those uncommon deposits where extreme leaching and chemical recombination have produced a clay of nearly pure mineral kaolinite. . Its whiteness, brightness, fine particle size, platelet shape, surface chemistry, and chemical composition make kaolin an important pigment, filler, extender and chemical compound in the paper, paint, plastics, ceramics and catalyst industries.

Jan 1, 1998

By Raoul Fernandez, Bernard Catalano, Guillaume Roux

The Thaumasia Joint-Venture, composed of Bouygues Travaux Publics, Soletanche- Bachy and Bessac, completed the construction of the underground section of line 2 of the Nice tramway, which comprised a 3.2 km twin track tunnel and four underground stations, in a particularly complex urban and geotechnical context. The density of the surface structures, as well as the presence of many historic buildings on its route made the construction of the tunnel even more sensitive, with a settlement threshold of Half an Inch. The joint venture faced a complex subsoil, varying from one extreme to another from highly plastic clay layers to fibrous peat and to cobbles with very high permeability, with artesian ground water, and with unforeseen anthropogenic obstacles in the tunnel section Due to the diversity of the problems encountered and their variability over short distances, the construction of the underground section of the Nice tramway, in its very sensitive urban context, undeniably constituted an unprecedented challenge.

Jun 13, 2023

By D. W. Frommer

In continuing its long range studies of methods of treating low-grade iron ores, the Bureau of Mines has developed a new selective flocculation, desliming, and flotation procedure that enables effective beneficiation of the finely disseminated ferruginous jaspers of the Marquette range, Mich. The process, developed on a bench scale and later confirmed in the 800-lb/hr pilot plant, comprises dispersion, selective flocculation, desliming to reject fine silica and clay, and flotation of silica from the remainder of minus 400-mesh pulps. Pilot plant flotation of two Marquette range ores, using the selective flocculation procedure on feeds containing 36 percent Fe, yielded iron recoveries of about 84 percent in concentrates containing 65 to 66 percent Fe and 4 to 5 percent silica. These results were metallurgically superior to those obtained when selective flocculation was not used. Also operating characteristics were better, and reagent costs were lower.

Jan 1, 1964

By Thomas E. Shufflebarger

Glass is one of man's most versatile creations. ---The earliest glaze known---is about 12,000 B.C. ---The oldest pure glass is a moulded amulet of about 7,000 B.C.---. Indicative of a knowledge of properly-proportioned, quality raw-material, means were found for producing the first relatively clear, transparent glass at about the beginning of the Christian era. The fundamentals of almost all the modern, technical processes of manufacture were established during the 3rd Century. (1) Glassmaking, practiced in Colonial America, was moved toward the Ohio Valley in response to increasing demands for fuel. This move, beginning in the 1860's resulted in the use of the glass sands contained in the Oriskany (and St. Peter) sandstone. (2) Glass sand,(3) virtually pure, fine-to-medium-grained quartz sand(4) is the principal raw material used in the manufacture of glass; it constitutes proportions which range to a maximum of about 72% and seldom is glass made without it. However, acceptable glass sands are, invariably, those which most nearly fit the glass-producer's economic needs and any method used to evaluate a raw material's potential must finally prove equatable with such needs. As used in the United States, source-rocks of glass sand include sandstone, unconsolidated silica sands, quartzites and vein-quartz. Admixtures of silica sand and other (principally clay and feldspar), readily separable components have been proven viable. However, the silica sand, refined by nature to a high degree of purity, is the desirable product of exploration. If the term, standard, is justified by long-continued use, the Oriskany - and St. Peter sandstones are, together, the nonesuch of the glass sand industry they provide the principal tonnage of melting sand. According to Grimsley,(5) Ottawa, Illinois, glass-sand is considered the standard glass-sand of the West and the analyses of Berkeley Springs sand (Oriskany) compare most favorably with this sand.

Jan 1, 1974

By Stanley O. Reichert

At nuclear facilities, three types of radioactive waste must be managed: (1) high-level liquid waste containing fission products from the chemical separation of irradiated uranium, (2) low-level condensates from the concentration of the high-level waste, and (3) dry solids such as obsolete process equipment, spent ion exchange resins, and irradiated metal scrap. The geological and environmental characteristics of a site are important considerations in planning the waste management program. At the Savannah River Plant, low-level liquids and dry solids are safely and economically placed in the soil where the geologic and hydrologic conditions are favorable. Within the general area where the waste originates, studies are made to locate seepage basins and burial grounds in the most favorable sites: (1) soils should have a high ion exchange capacity and moderate to low permeability, (2) the water table should be deep, and (3) burial sites should be relatively distant from the nearest flowing stream.

Jan 1, 1968

By J. Bacho

The modern drilling fluids industry is a dynamic, evolutionary environment. It is continuously striving to satisfy and anticipate the ever-changing needs of the oil and gas industry. The predominant driving forces in the industry over the past decade have changed dramatically. Health and environmental issues, coupled with economic and performance requirements, demand innovation and change from the drilling fluids industry. Emerging drilling fluid technologies will demand environmental considerations from mined components with additional emphasis on cost and performance criteria. Drilling fluids providers continue to search for and identify environmentally sensitive components which meet or exceed the performance of their more toxic predecessors. These changes have and will impact the components of drilling fluids that are mined.

Jan 1, 1994

By William A. Faust

At Gold Fields' Chimney Creek Mine, major reviews of the reclamation and closure plans are done concurrently with the annual mine planning required for budget preparation. This review includes identifying and scheduling reclamation work that can be done within the next few years and development of associated costs. Longer term mine, leach pad and waste dump development are examined to take advantage of any design changes that can reduce ongoing reclamation or closure requirements and reduce costs. The success and cost effectiveness of past efforts are continually evaluated to determine the best methods for reclamation.

Jan 1, 1992

By L. M. English

In the past 30 years, the research arena has changed significantly in all fields, mining included. The relative representation of the topics of research, how the research is performed, and who has performed the research have all changed significantly over these decades. Although there are a lot of subjective ideas concerning these changes, and there is a fair amount of anecdotal "analysis," there has been no actual study of these trends to verify the facts. The period studied is divided into six five-year periods for the purposes of comparison. Some of the trends analyzed are as follows: ? Co-authorship ? Research areas ? Research sponsors ? Cooperative efforts

Jan 1, 1995

By Yuting Xue, Khaled Mohamed

The failure of coal ribs is a major hazard in underground coal mines. Researchers from the National Institute for Occupational Safety and Health (NIOSH) have been working on the development of an engineering-based rib control method. A user-friendly standalone application, called Design of Rib Support (DORS), is being developed to ease the calculations of rib support. DORS can estimate the Primary Rib Support Density (PRSD, ton/ft2) for development loading. However, it still needs to take account of another key factor, bolt length, in rib support design. The bolt length can be estimated from the rib fracture depth, and this study focuses on the coal rib fracture depth analysis with numerical modeling and artificial neural network. A total of 331 FLAC3D simulations with different mining scenarios and rib conditions were conducted for this study. Machine learning was then used to predict coal rib fracture depth under different conditions. Based on the numerical simulations, the parameters for mining scenarios and rib conditions were collected as features for machine learning, and coal rib fracture depths were collected as the target to predict. Good data correlation (r-square) was obtained with the use of an artificial neural network. The

By G. Ferrara

To obtain a reliable comparison between conical and cylindrical separatory vessels used in dynamic dense medium separation systems, the following studies were made: (1) study of the swirling flow in conical and cylindrical vessels using laser-Doppler velocimetry (LDV); (2) study of the behaviour of suspensions of magnetite and ferrosilicon in water in both separators. It was found that: (a) the tangential velocity profiles differ in conical and cylindrical vessels: in a conical cyclone free vortex conditions affect the largest part of the vessel, while in a cylindrical vessel, the motion approaches that of a forced vortex, i.e. that of a centrifuge; (b) the conical vessel manifests higher centrifugal acceleration and very strong densifying; the density differential, and hence the density gradient inside the vessel is large; (c) the cylindrical vessel manifests lower centrifugal acceleration and low densifying, i.e. low density differentials, and hence, the density gradient inside the vessel is small; (c) due to greater densifying, the density cut-point in cyclones is higher than the operating medium density, while in cylindrical vessels the density cut-point is closer to the medium density. The results provide an interesting description of the differing behaviour of conical and cylindrical vessels and help explain the differences in performance between the two types of separators.

Jan 1, 1998

By Richard E. Thill

Backfilling of mine voids is used to prevent or control the effects of subsidence on surface structures. The pumped-slurry, blind-backfilling process has been particularly successful for stabilizing ground over abandoned and inaccessible underground coal mines. Using this newer technology, vast quantities of backfill material can be distributed over wide areas in underground openings from a small number of injection boreholes. The rapid and successful development of this backfilling method, however, has outstripped technology for monitoring and controlling backfill placement. Surface or borehole remote sensing methods are needed to determine where fill material is being distributed underground and how effectively the material is packed in the voids. In search for improvements in backfill monitoring and control technology, potential remote geophysical sensing, process monitoring, and tracer methods were evaluated to select candidate systems for monitoring backfill placement under the constraints imposed by the injection process and the surface and subsurface conditions. ' A multiple objective ranking matrix, based on theoretical considerations as well as pragmatic experience with systems working in related or similar conditions, was used to narrow down potential methods to several most-favored candidates. Two of the candidates were field tested under actual operating conditions at a backfilling site in the Wilkes-Barre-Scranton region of northeastern Pennsylvania. Although process and acoustic emission monitoring indicated promise for improving existing backfill monitoring technology, more extensive testing under different conditions at various sites is required to establish the validity and utility of these methods. Results indicate that no single method is adequate in itself for backfill monitoring, and that a successful system will require the Integration of several methodologies.

Jan 1, 1982