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By John E. Husted

Universities have education as their primary purpose. This appears to be an innocuous statement with simple meaning. In an age of conflicting semantics, however, cords and meanings are often lost or changed. The term education is often broadly expanded to encompass any form of learning process, or the accumulation of knowledge, and even to the beneficial application of knowledge to man's problems, hence one find that education in universities is not solely the formal process of texts, lectures, recitations, and testing by a batch process known as class room teaching. Despite critics of education batch is spelled with an "a", instead of an "o" - at least we hope so If one defines teaching as causing to learn, then the learning objectives may necessitate a variety of approaches within the teaching concept and research is among those favored at the graduate and some undergraduate levels. Research has been among the glamour words and certain fields such as oceanography and space science have had more than their share of glamour. Unfortunately, industrial mineral research has not had the competitive drawing power of enamoring students of the "note" generation in terms of glamorous accomplishment. Research today usually requires sophisticated equipment and such equipment is expensive, both for initial purchase and operation. Again, administrations, be they industrial, government, or academic, usually require

Jan 1, 1970

By George W. Parker

The ever increasing costs of labor and supplies have made it imperative that operators of open pits look for some way in which to cope with these increases. One of the most logical ways to increase the efficiency of an operation is by the introduction of larger haulage equipment, as generally haulage costs are the greater portion of the over all expenses. These larger haulage units require larger shovel units. In the late 1930's and the early 1940's large mining, quarrying and heavy construction operations had more or less standardized on the 4 to 6 cubic yard shovels. During this same period the haulage units were generally 22 to 27 tons. Some ten years ago 9 - 13 cubic yard shovels along with plus 50 ton haulage units were introduced by manufacturers in an effort to enable operators to decrease costs.

Jan 1, 1962

By M. Moats, I. E. Paschalidou, K. Awuah-Offei

Tellurium (Te) is a rare metalloid that is predominantly produced from the treatment of anode slimes formed during copper (Cu) electrolytic refining. The US Government lists Te as one of the 50 critical minerals, partly, because of its use in thin-film photovoltaic (PV) technology. Given policy initiatives to increase Te production, it is important to evaluate the life-cycle environmental impacts of Te recovery as a by-product of Cu processing. The literature contains a few specific life cycle assessment (LCA) studies of groups of metals that include Te without proper regard to impacts per life-cycle stage of Te production or the effect of allocation on the results. This study builds an LCA model of the production system of Te from anode slimes treatment to evaluate the effect of allocation on life-cycle impacts. We build life cycle inventories using data from the Ecoinvent v3.7.1 database, literature, and engineering calculations and allocate impacts in proportion to products’ mass and economic value. The results show that economic value-based allocation yields greater impacts than mass-based allocation indicating the significant effect of the allocation approach on life-cycle impact estimates.

Feb 1, 2023

By R. Buchan

A number of mineral processing techniques have been adopted for the separation of the plastics making up a typical beverage bottle, and a complete flowsheet developed. Thus, size reduction, heavy media separation and flotation were used to separate PE, PVC and PET from their mixtures with cellulose fibers and aluminum, which makes up the cap of such bottles. It is shown that while heavy media separation allows the separation of a PVC/PET mixture from the solid waste, froth flotation can be readily used to separate PVC and PET from a mixture of the two. For this purpose, the differential action of an alkaline aqueous solution (PH=II) which contains methanol and MIBC as surface tension control agents has been found to be a suitable flotation medium. This paper reports some aspects of the flotation flowsheet developed for the separation of plastics from municipal solid waste mixtures and PVC from PET.

Jan 1, 1995

By Tedd B. Bodimer

Why complicate an already complex machine such as a continuous miner by adding roof drills? Immediate permanent roof support is an immediate thought of the mining engineer just as elimination of frequent time-consuming places changes is a thought of the methods engineer. The realization of those two objectives has the potential for improved safety with increased production is the thought of the general manager. Miner-Bolters Used a Generation Ago These are not new thoughts as the 1CM continous miner equipped with two integral roof drills was introduced twenty-five years ago. Approximately two hundred of these machines were sold in the next five years for use in medium and high seam operations. The 1CM miner chassis that remained stationary in the center of an entry or room while the ripper bar was swung and sumped hydraulically provided an ideal platform for mounting two roof drills that could be operated during the continuous miner's production cycle. Two roof bolts could normally be installed in less time than required for the mining cycle. A typical roof drill unit is shown in Figure I.

Jan 1, 1981

By David G. Chedgy

Noise control is an important consideration in the design and operation of coal preparation plants. It is essential to understand and control noise sources to provide a safe environment for operating personnel. The average noise exposure levels in a typical coal preparation plant generally range between 95 and 100 db. An operator should not be exposed to noise levels of this magnitude for more than 4 and 2 hr, respectively, according to MSHA (Mine Safety and Health Administration) regulations. The major noise sources in a coal preparation plant include noise from impacting the inside surfaces of steel chutes, vibrating screens, coal crushers, pumps, motors, fans, and blowers. The magnitude of noise varies considerably from one situation to another. NOISE EXPOSURE IN COAL PREPARATION PLANTS Noise regulations established by the Occupational Safety and Health administration (OSHA) are accepted by MSHA relative to caal preparation plants. Fig. 14-43 shows a graph of the time of noise exposure in hours per day to which a worker can be exposed for each A-weighted sound level. According to this graph, a worker is permitted to spend 8 hr in a 90-db noise environment, but that time must be halved when the A-weighted sound level increases 5 db. The noise dosage a worker receives is determined by the ratio of the length of time the worker spends in a particular noise environment divided by the length of time he is permitted to spend in that environment. If the worker is exposed to several different sound levels, his total dosage would be the sum of each of the individual dosages. The equation for determining the dosage is: where C is the actual duration of exposure at a given steady state noise level and T is the noise exposure limit for the level present during the time C According to MSHA regulations, the dosage, D, should not exceed one (1) for any worker for a full day of work. As an example of typical plant noise levels, vibratory screens and crushers emanate noise levels in excess of 90 db at a distance of 3 ft (0.9 m) with no material flow. With material flow, noise level increases 1 to 10 db depending

Jan 1, 1991

By J. D. Grace

[Screening by centrifugal force is an unique, subject, for with the exception of only one vibrating screen presently on the market, all vibrating screens depend upon, gravity to pass material through a sizing mesh or screen cloth. This one screen that sizes by centrifugal force and utilizes gravity only to convey materiel along the screen, is the SYMONS V-Screen. This screen was designed by Loren Symons, a member of the family that has contributed so much to the metallic and non-metallic mineral processing industries. Among Symons' other outstanding contribution to these industries are the original Cone Crusher which revolutionized reduction crushing practice, the first high-speed horizontal vibrating screen, the original Rod Deck Screen, and one of the earliest vibrating Bar Grizzlies.]

Jan 1, 1965

By R. R. Klimpel

This paper describes four new families of flotation products which are currently being introduced at the industrial level. A brief summary of the chemical basis behind each product family will be given. This is then followed by a selection of flotation examples which illustrate the more important use characteristics that have been observed to date. It is becoming more apparent with further testing that these four new product families can offer both technical and economic advantages to the industrial flotation process operator.

Jan 1, 1992

By Debra W. Struhsacker, Jean Kiel, Jeffrey Thatcher

3.1 INTRODUCTION As heap leach precious metal projects become increasingly common in the United States, federal, state and local regulatory agencies are beginning to take a closer look at the short- and long-term environmental consequences of this recovery technology. From an operator's point of view, there is seemingly a confusing regulatory maze to be navigated and a plethora of permits and approvals to be obtained prior to commissioning a heap leach operation. The degree of difficulty associated with obtaining permits for a heap leach project depends largely upon the state in which the project is located. Permit acquisition is generally easiest in those states most familiar with heap leaching technology. For example, heap leaching is well understood in Nevada, and heap leach operations are relatively easy to permit, although permitting conditions in Nevada have recently become more stringent. However, many states are just beginning to become familiar with heap leach operations. Many of these states such as Idaho, Colorado, South Dakota, Oregon, Montana, Washington and South Carolina are in the process of drafting regulations and establishing guidelines for heap leach projects. In most cases, these regulations specify design and operating criteria as well as reclamation and decommissioning procedures. This chapter provides an overview of the regulatory and permitting aspects of heap leach operations. Permitting requirements for projects developed on federal land are discussed in detail. 'The state and local regulatory atmosphere and permitting requirements for various states are also presented. The chapter concludes with a generic permitting strategy. 3.2 KEY ENVIRONMENTAL CONCERNS The primary concern of most local, state, and federal regulatory agencies is the use, storage and transport of sodium cyanide (NaCn), and potential cyanide contamination of surface and groundwater resources. The toxicity of cyanide to people, fish and wildlife is also an important issue. Unfortunately, in the public eye, cyanide heap leaching has some emotional impacts similar to those associated with radioactivity and uranium mining. This perception and the general lack of understanding of cyanide can lead to unnecessary concern about cyanide contamination, further complicating the regulatory environment.

Jan 1, 1988

By E. Medina, W. Callupe, R. Sharon

Slope stability in Barrick’s Pierina Mine open pit is significantly influenced by the structural geology, the variably argillized rock mass, and locally by perched groundwater. Development of an extensive surface water diversion network continues at Pierina, which is necessary to minimize highwall and adjacent natural landslide movement and erosion during the wet season. Slope movements are effectively monitored using optical survey methods, strobe light extensometers, gap monitors, and piezometers. The slope stability program at Pierina is focused on improving the understanding of the stability mechanisms in order to ensure continuous safe operating conditions. Priorities are placed on developing an accurate detailed engineering geological model, enhancing groundwater depressurization, and optimizing highwall controlled blasting procedures.

Jan 1, 2003

By E. J. Karges

The use of pulverized coal for generating power and performing industrial processes has made an important contribution to our industrial economy during the past half century. Actually, the burning of coal in powdered form is a subject that has held the attention of engineers for a century or longer. Its widespread use, however, is comparatively recent, As early as 1866 patents were granted to Messrs. Whelpley and Storer for a method of feeding pulverized coal into a furnace as an auxiliary to the grate fuel. In the many tests made during the subsequent years with various kinds of apparatus, the experimenters were handicapped in not getting the coal fine enough to obtain complete combustion and to prevent excessive formation of slag.

Jan 1, 1965

By Y. J. Son, S. S. Nageshwaraniyer, K. M. Kim

"This paper reports on the development of a simulation-based framework for obtaining optimal blast design parameters for a hard-rock mine. To do this, a conventional medium-sized hard-rock mine was taken as a case study. The mine has two pits containing hard and soft rock types. The proposed framework contains a combination of regression analysis using Excel software by Microsoft and discrete-event simulation using Arena software by Rockwell Automation, applied to construct a model of the material-handling network of the mine. Specifically, blasting parameters are estimated by Excel-based regression analysis, processes including blasting and haulage from pits to crushers are modeled by a Forward Blasting simulation submodel, and material-handling operations including crushing, storage in stockpile, and haulage via conveyors and into SAG and ball mills are modeled by a Crusher to Ball Mill simulation submodel. A Reverse Blasting submodel is then used to obtain the optimum blast design corresponding to a target P80 particle size. Using the proposed framework, an economic analysis was performed to demonstrate the cost savings that could be realized for each rock type as a function of specific explosive energy. IntroductionIn a modern hard-rock mine, various processes such as drilling, blasting, crushing, grinding and mineral liberation are optimized to increase productivity, a practice known as mine-to-mill (MTM) optimization. Blasting is important in MTM optimization as it is the first comminution process and has an impact on all downstream processes (Julius Kruttschnitt Mineral Research Centre, 1996; Nielsen and Lownds, 1997; Nielsen and Malvik, 1999; Chung and Katsabanis, 2000; Kim and Kemeny, 2011a; Kim and Kemeny, 2011b).Two main research topics have emerged in the area of blasting design: (1) identifying the optimal target blast fragmentation at each shot and (2) controlling the blast fragmentation for that target. As part of an MTM optimization study, Kim and Kemeny (2011a; 2011b) developed a site-specific blast fragmentation prediction model that can be used to identify the target blast fragmentation and can be incorporated into MTM optimization. They also reported methodology for assigning model parameters easily and with minimal human bias."

Jan 1, 2015

By Emil Szaks

[A great number of papers have been presented at various Engineering Society meetings on the Unit Train subject. Moat are descriptions of facilities that have been constructed or are abort to be built. Many describe the facility as being the World's fastest, newest, largest, incorporating the latest technology and so forth, Many are duplications of installations that have been recently constructed, sort of carbon copies but perhaps arranged differently. The trend has been to incorporate loop tracks, rotary dumpers, indexers and, of course, the snivel coupler equipped unit train. How that the energy crisis has increased the use of coal, there has been a tremendous Increase in applications for permits to construct rail to river coal loading facilities. This paper is different. It does not describe any single existing facility, but is given to alert prospective terminal owners and engineers that there are items that require considerable study and evaluation beside merely selecting an indexer, car dumper, stacker, ship or berg loader and so on. An important item is the selection of the railway car which in turn can affect the selection of the method of loading and unloading. Let us list a few of the items that should be considered and discuss the areas that require examination:]

Jan 1, 1979

By John A. Wolfe

Applications of mathematical statistics to the field of exploration are still relatively new. There are two primary reasons why little has been published in this field. First, if one discovers an effective technique for exploration, he does not like to disclose it. Second, the geologist needs to work closely with a mathematical statistician, and the communications barrier between the disciplines is formidable. The authors of this paper, one a geologist and the other a statistician, were interested in the economic benefit which appeared to be possible in the interdisciplinary area which they have called "geostatistics." An actual example has been selected to illustrate this benefit.

Jan 1, 1962

By D. R. Nagaraj, Napoleon Tercero, Raymond Farinato

Historically, as for most reagents used in flotation, the wide-spread use of dialkyl dithiophosphinates as collectors in practical applications has preceded a detailed scientific understanding of how they work. Dialkyl dithiophosphinates are a technologically and commercially important class of collectors used in the flotation processing of Cu-Au, complex polymetallic, and precious metal ores. Plant usage has demonstrated that dithiophosphinates exhibit higher selectivity and flotation rates for Cu sulfides, galena, and precious metal values in the presence of other gangue sulfides, than the traditionally used collectors such as dialkyl dithiophosphates and xanthates. They also have an attractive health, safety, and environmental (HSE) profile. Although dithiophosphinates received little attention in the past in the flotation research community, recently, there has been significant interest in this chemistry, and numerous studies have been conducted to understand the fundamental interactions of dithiophosphinates with several base metal sulfides and precious metals. A critical overview of fundamental studies, laboratory ore flotation, and plant practice of dithiophosphinates is given in this paper. The findings from these studies are rationalized and explained by drawing on concepts and insights from coordination chemistry. A comparison between the interactions with various minerals and metals of dithiophosphinate and dithiophosphate analogues brings out some of the subtleties that seemingly minor changes in collector chemistry can make. The critical overview and analysis given here is useful in identifying gaps in knowledge regarding this important class of compounds. This in turn can provide a basis for the design of studies to advance our understanding of dithiophosphinate flotation performance.

By Robert D. Schmidt

The Bureau of Mines is conducting an investigation to develop remediation techniques for residential water wells whose yield has been affected in the long term, by underground mining. Initial work relating to this project was conducted in 1984-1987 at a room and pillar mine in Indiana County, Pennsylvania. Piezometer nest data from the room and pillar mine reveals that a downward gradient in piezometric head exists in shallow strata as a result of drainage into the underlying mine void. The vertical gradient in head in turn results in well bore leakage in open-hole water wells. The relative yield of valley wells is only slightly affected however because the high surficial recharge rate through fractures more than compensates for fracture leakage into the underlying mine. The relative affect of well bore leakage on well yield is greater in certain hillside and hilltop wells that have comparatively low inflow rates at shallow depths. The static water level of such wells is determined to a much greater extent by the chance interception of deep outflow fractures, than is the case for wells drilled in a more intensively fractured valley bottom. The lower static water level of wells that intercept deep fractures does not necessarily reflect the water table conditions outside of a small radius around the affected well. The results suggest that permanently isolating well bore outflow fractures may remediate certain open-hole residential wells that have been affected by high extraction underground mining.

Jan 1, 1986

By Steven M. Bishoff

The reclamation of surface land areas disturbed during the course of coal recovery became a major, universal consideration upon the implementation of the Surface Mining Control and Reclamation Act of 1977. This legislation not only established reclamation as an absolute requirement, but also presented guidelines for reclamation standards and required bond-posting procedures to assure completion of the reclamation process. The Office of Surface Mining was established to enforce the provisions of the Congressional mandate by promulgating specifically detailed regulations and supervising the State participation in this regulatory process. The major operational consequences of the reclamation-related provisions of the Act and the OSM regulations are the increased costs and complex procedures necessary to accommodate the regulatory authorities. It is anticipated that many of these costs and procedures have not been adequately evaluated by either the coal operators or the regulatory bodies. It is, therefore, necessary to proceed with an examination of the general reclamation processes, the effect of these processes on product costs, and the methods, if any, which may be utilized to minimize their impact on the overall operation.

Jan 1, 1981

By M. Popescu

In the southern part ?f the Occidental Carpathians an iron ore body embedded in crystalline schist was exploited. The presence of minerals such as magnetite, pyrite, pyro-chorine, allanite, monazite and xenotime, which also include within their structure substituted thorium isomorphic, was pointed out. The iron ore was processed by crushing, grinding and magnetic separation in order to obtain magnetite concentrates. The environment was affected by pollution generated by the mining activities. In 1995 due to the economic reasons, it was decided to cease mining exploitation and remediate the area. The paper presents the ecological impact caused by mining activities on a number of environmental targets and the population. The pollution sources, namely sterile dumps and mine waters are characterized (from the physical, chemical and radiometric point of view); the pollution pathways and theirs effects on potential targets, namely soil, vegetation, hydrographic network and population are identified as well. The degree of pollution due to all sources was assessed and maps of pollution sources distribution were generated. The supplementary effective doses for the population were assessed using rigorous scenarios and considering all exposure pathways. The rehabilitation plan includes solutions for dumps geometrization, covering and revegetation as well as mine waters management.

Jan 1, 2005

By Ernst P. Hall

The Irwin Basin. (Fig. 1)* is a synclinal or shoe-horn *Figure numbers throughout refer to color slides not included with the preprint shaped basin in the Pittsburgh Coal Seam, It is approximately 10 miles wide and 22 miles long at its maximum points. The surface of the land above the basin is hilly, rolling farmland,, typical of this area of Pennsylvania, and it is criss-crossed with streams and highways and liberally dotted with farm houses and communities. In-general the coal is pitched from north to south with a total drop of 610 feet'. The coal seam cross-section from east to west is bowl-shaped and rises as much as 375 feet from the low point of the bowl to-the-outcrop. Cross-sections showing coal elevations are shown on Figs, 4 and 50 Ground cover above the coal will vary from 0 to 550 feet, averaging about 350 feet throughout the area. This area is richly endowed with a history of coal mining. The first car of coal shipped cast of the Allegheny Mountains was mined in the Westmoreland Coal Company's Shady Grove (later North Side) Colliery in Irwin, Pa., early in 1853, This mine was opened in 1852 by Coleman, Hillman & Company. The coal was hauled from the mine to the freight station by horse-drawn wagon and. loaded into a then "standard" box car of 18,000-pound capacity. Coal mining in this region flourished and grew as steel production in nearby Pittsburgh demanded more and more of the high quality, metallurgical-grade coal of the region.

Jan 1, 1959

By Matthew S. Sanchez, Richard J. Lee, Matthew D. Zock, Drew R. Van Orden, Yumi Kamiya, Edward B. Ilgren

In many developing countries, asbestos is still used for friction products, insulation, and asbestoscement products. However, there is very limited modern data evaluating the airborne concentrations of asbestos fibers in operating asbestos plants. We have conducted an Industrial Hygiene survey, using state of the art PCM and TEM analysis, of a Bolivian asbestos cement plant that uses crocidolite during the production of roofing shingles and water tanks. The study is the first to use modern analytical measurements in an uncontrolled asbestos environment. Thus, this study offers insight into the historical airborne exposures at asbestos plants operating before modern dust control measures were introduced or airborne fiber levels regulated. The results suggest that fiber concentrations are far in excess of those for which current models would predict the onset of asbestos disease and mesothelioma. Significantly, the plant and community do not have an elevated incidence of asbestos disease or mesothelioma. Airborne fiber levels during comminution and fiber sizing ranged from 100 to as much as 1,000 f/cc. Fiber levels in the mixing, forming and finishing areas ranged from 0.5 to 9 f/cc. Based on the number of overloaded samples and estimates of their concentration, historical estimates of exposure may be underestimated by an order of magnitude. Also, an excellent correlation (1:1) between the PCM and TEM fiber concentrations (for fibers _0.25 um diameter) were obtained, raising questions about the conventional wisdom that the PCM systematically undercounts fibers. The results of this study further indicate that current models may overestimate the risk of asbestos disease and mesothelioma.

Jan 1, 2012