Search Documents

By Charles L. Kimbell

The year 1986 was not a good year for the world's mineral industry from several viewpoints. Levels of production, both of crude minerals and processed forms, registered declines in the cases of a greater number of commodities than the number that recorded increases. The overall value of world crude mineral production was estimated to have increased, but only very slightly in terms of constant dollars to nearly $997 billion. Although there were modest increases in the consumption of all major fuels and most major metals, the latter at least apparently resulted more from drawdowns of inventories than from increased production (fuel consumption increases did come from higher output levels), and consumption of most major fertilizer and chemical commodities (nitrogen, phosphate, and sulfur) were at lower levels than those in 1985. Prices for a number of mineral commodities declined, headed by the very substantial drop in world crude petroleum prices, but also including downturns for a number of metals and industrial minerals as well. There was insufficient information to reliably fix the level of the dollar value of world trade in minerals, for while output was up in the case of some large-volume materials such as iron ore, coal, and crude and refined petroleum, suggesting that the volume of trade in physical units may have increased, declining prices may well have offset quantitative gains.

Jan 1, 1988

By Gary J. Cwick

Mineral resources of the Rice Valley Wilderness Study Area (WSA), in the Mojave Desert of southeastern California, were investigated by the U.S. Bureau of Mines and U.S. Geological Survey during 1980. The study consisted of an examination of mines, prospects, and mineralized areas by the Bureau: of Mines and geological, geochemical, and geophysical investigations by the Geological Survey. Little indicated potential for the presence of mineral resources exists in the valley floor segment of the study area. The Big Maria Mountains section of the study area has some potential for mineral resource development. Decorative building stone from both bedded quartzite deposits and weathered limestone surface rubble (driftwood stone) has been produced from the Big Maria Mountains segment of the study area. Total production is unrecorded but probably small. A 700,000 ton (640,000 t) quartzite resource was inferred and 4,500 tons (4,100 t) of driftwood stone within the study area was estimated. A relatively pure limestone deposit inside the study area contains an inferred resource of 14 million tons (13 million t). One prospect suggests a potential for the presence of manganese resources although none were estimated. The likelihood of discovering oil, gas, coal, uranium or geothermal energy is low; potential sources are not known to exist.

Jan 1, 1982

By John Organiscak

A majority of continuous mining machines employ a water spray system and a machine mounted flooded-bed scrubber to suppress and capture dust during coal mining. These machine mounted dust control systems must be designed to function within the localized face ventilation system at the mining section to control both dust and methane. Spray systems can impede or improve the scrubber effectiveness in controlling dust or methane at the mining face. Laboratory experiments were conducted to examine the effect of spray type, spray pressure, machine body blocking sprays, and scrubber airflow on dust and gas levels while using a 12.2 m (40 ft) exhaust ventilation curtain setback from the face. These experiments were conducted with the mining machine positioned at the end of a simulated 6.1 m (20 ft) sump and slab cut. Results indicate that the hollow cone nozzles with blocking sprays best complemented the flooded-bed scrubber performance in an exhaust ventilation system. This external spray system notably reduced dust and gas levels on the off-curtain side of the mining machine for both the sump and slab cut as compared to the flat spray nozzles. Higher scrubber airflows reduced dust and gas levels on the curtain side and in the return of the continuous mining machine. The remote operator position, located on the off curtain side and parallel to the inlet end of the exhaust curtain, sustained the most stable and lowest dust levels around the mining machine.

Jan 1, 2010

The coal-bearing strata of Oklahoma occur in the eastern part of the state over an area of 14,500 square miles, 20.7 percent of the state's total area. Commercially valuable deposits of bituminous coal cover about 8,000 square miles in seams ranging from ten inches to five feet thick. Estimated reserves in Oklahoma are 1.6 billion tons, representing 0.3 percent of U.S. coal reserves. The vast majority of coal mined in Oklahoma used in a single power plant within the state. Oklahoma gained primacy when its regulatory program was conditionally approved January 19, 1981. Authority for the state to administer the Abandoned Mine Land program was granted January21,1982. On April 30,1984, the Office of Surface Mining substituted direct federal enforcement of the inspection and enforcement portions of the Oklahoma program. This substituted enforcement was based upon a finding by OSM that Oklahoma had not operated the inspection and enforcement portions of its program effectively. As of January 1, 1986, Oklahoma inspection and enforcement authority was reinstated. Full program authority was granted to Oklahoma on January 14, 1986.

Jan 1, 1992

By R. P. Vinson

Assessment of workplace exposures is an important tool for helping to minimize dust-related occupational illness and diseases. Real-time particulate monitoring can effectively locate areas where dust controls are needed and determine how well they are working. An affordable, person-wearable, real-time dust monitor is needed. The SKC Inc. Dust Detective (SKCDD) fulfills those requirements (Disclaimer: Mention of any company or product does not imply endorsement by NIOSH). The SKCDD consists of a disposable sampling tube (DST) connected to a small hand-held sampling pump. The SKCDD was developed through a Cooperative Research and Development Agreement (CRADA) between the National Institute of Occupational Safety and Health (NIOSH) and SKC Inc. The relationship of dust concentrations measured by personal gravimetric samplers to those measured by the SKCDD was determined in a laboratory aerosol chamber. A comparison of the means and the relative standard deviation of triplicate measurements of each type of sampling device demonstrated the SKCDD to be a viable alternative means for measuring dust. While it provides accurate measurements for specific coal types, it requires correction factors (those correction factors still need to be calculated) for other coal types.

By E. R. Maize

[?he scconG rcport of :his st?rI.org 8cdt with o3servatioi:s of conver- gence of roof an4 floor at t!x*re: ?.cc.-.tioris iri til~ ClVucible mine of kke Cru- cib1.o Fuel Co. Data on sl:'ociacnce ?.rd Lztcrcl mwe:~cnt cf the surface were .:lven for two of these areas, cnS it was mentioned that ~lr~~ilar data were being obtained on a ?art of Pe:sc:rlvtzr.ia Fii~l?trr.y FE:, ~i!lic;l pcser: over the third area. 'I'hie hichwc :LEO FasseE over t!lc ITenncoli::. :.line of the Bnckeye Coal Co. 9 milcs to ';he so-lth, cnd at P. l~tcr C'..att: ~.nr?r.,cc?r:cntS *.rere mnd.e to make similar observati on3 there. This y: pr mrnmri:.c n Czto obtnino? at those two locetionn,]

Jan 1, 1941

By Charles B. Carpenter

In general terminology, the West Texas Permian Basin companies the area south of the Texas Panhandle and west of the Bend Arch or Central Basin region. It is outlined more definitely by geologists however, as that area underlain by the south half of the Permian Salt Basin4/ and includes Scurry, Mitchell, Sterling, Howard, Glasscock, Reagan, Crockett, Upton, Midland, Martin, Gaines, Andrews, rotor, Crane, Pecos, Ward, Winkler, and Loving Counties in Texas, and.. Lea and Eddy Counties in New Mexico. The oil fields of the area, of which more than 70 have been discovered, are shown in fire 1. Approximately 4,200 producing oil wells have been drilled in these fields. Oil has been produced from limestones and dolomites of Permian age in most of the fields in the West Texas Permian Basin. Some of the fields produced oil from sandstone beds above the limestone, and in two fields production has been found below the limestone in formations of Ordovician age.

Jan 1, 1936

By Charles B. Carpenter

In general terminology, the West Texas Permian Basin comprises the area south of the Texas Panhandle and west of the Bend Arch or Central Basin region. It is outlined mere definitely by geologists, however, as that area underlain by the south half of the Permian Salt Basin4/ and includes Scurry, Mitchell, Sterling, Howard, Glasscock, Reagan, Crockett, Upton, Midland, Martin, Gaines, Andrews, Ector, Crane, Pecos, Ward, Winkler, and Loving Counties in Texas, and Lea and Eddy Counties in New Mexico. The oil fields of the area, of which more than 70 have been discovered, are shown in fire 1. Approximately 4,200 producing oil wells have been drilled in these fields. Oil has been produced from limestones and dolomites of Permian age in most of the fields in the West Texas Permian Basin. Some of the fields produced oil from sandstone beds above the limestone, and in two fields production has been found below the limestone in formations of Ordovician age.

Jan 1, 1936

By David C. Grant

A laboratory technique for simulating in-situ uranium mining was developed and used to determine the effects of leaching variables on permeability, uranium recovery, leach solution interaction with the ore-aquifer environment, and post-leach chemical leakage. In particular, ammonium bicarbonate, the commonly-used leach solution, was examined in great detail. Agitation leach tests were conducted to examine the effect on ammonium sorption and desorption of clay content, solution and clay ammonium levels, pH, and the type and concentration of other anions and cations in solution. Initial column tests were performed to determine the degree of ore-aquifer interaction that could be expected for various leach solutions; sulfuric acid, and ammonium, sodium, and potassium bi-carbonates. Subsequent tests examined various methods to restore the ores by lowering the post-leach chemical leakage. The restoration tests examined the use of reducing agents (e.g., ammonium bisulfite, sodium bisulfite; and sodium sulfite), ore blocking and stabilizing agents (e.g., sodium silicate, aluminum chloride, and magnesium-calcium salt).and ammonium displacement agents (e.g., aluminum chloride and lanthanum chloride-sulfate)

Jan 1, 1980

Objective: To help prevent squeezes, collapses, and other pillar failures through better pillar design, thereby enhancing safety for underground mine workers.

Jul 1, 1997

A revolutionary development in blasting materials has occurred in recent years. Ammonium nitrate, sensitized by the addition of a small percentage of No. (class) 2 diesel fuel or other suitable petroleum product, has been adopted as a low-cost, efficient blasting agent2 in a wide variety of mining, quarrying, and heavy construction operations. Moreover, the ready availability of the component supplies throughout the Nation, together with the ease of formulating them into effective blasting agents, has made it possible for the blaster himself to prepare the mixes at the site of use. Recently, most established explosives manufacturers have begun supplying premixed AN-FO (ammonium nitrate-fuel oil) or a comparable product to various mining operations. However, many individuals and small business establishments are marketing premixed products prepared in facilities that are often poorly constructed and poorly located. Although these blasting agents have partly or wholly displaced explosives such as dynamites in many applications, there are some blasting operations in which the fuel-sensitized ammonium nitrate agents do not appear to be well adapted. As long as the hazards they present are clearly understood and respected, ammonium nitrate-based blasting agents have important safety characteristics when prepared under competent factory control or field-mixed under equivalent close control. This publication attempts to summarize the knowledge of those hazards and to incorporate practical ways to cope with them.

Jan 1, 1963

By Donald I. Bleiwas

The U.S. Bureau of Mines has evaluated the potential availability of nickel from 36 deposits or districts in 16 market-economy countries (MECs), analyzing more than 95 percent of production in those countries. This study indicates the quantity of nickel available on the basis of net production costs and total costs with a 0-pct and a 10-pct discounted cash flow rate of return (DCFROR). Costs of production are expressed in dollars per pound of recovered nickel. The study also indicates sensitivities of the cost of production to energy, labor, and other factors. The studied deposits and properties contain approximately 33 Mmt of recoverable nickel. About 26 Mmt of nickel is potentially recoverable from laterite deposits, of which 4.5 Mmt can be produced at $2.50/lb or less with a 0-pct DCFROR. Approximately 7 Mmt of nickel is potentially recoverable from sulfide deposits, of which about 6.3 Mint could be produced at $2.50/lb or less at a 0-pct DCFROR. The price of nickel averaged above $6.00/lb in 1988. Sensitivity studies performed for both laterite and sulfide deposits indicate that the total cost of producing nickel from laterites is most sensitive to increases in energy costs and that the total cost of producing nickel from sulfide deposits is most sensitive to increases in labor costs; sulfides are also affected by changes in revenues from byproducts.

Jan 1, 1991

By Robert F. Randolph

Real-world levels of attenuation from hearing protection devices are usually much lower than the rated values obtained under near-ideal circumstances. The shortfall is even more extreme for earplugs than it is for earmuffs, primarily because of the complicated process of fitting the plugs within the ear canal. This study examines the use of a commercially-available lubricant for hearing aids to determine whether it would facilitate improved fit and attenuation for earplugs. In this experiment, ten participants inserted earplugs with and without using the lubricant. Average attenuation was assessed with the Real-Ear-Attenuation-at-Threshold (REAT) technique, and showed over 5 dB improvement when the lubricant was used. Participants obtained an 85% mastery rate using the lubricant versus a 50% mastery rate without. These results indicate several possible applications for improved earplug performance in real-world settings where hazardous noise is unavoidable and effective hearing protection is necessary.

Jan 1, 2008

By Peter G. Kovalchik, Rudy J. Matetic, Susan B. Bealko, Adam K. Smith

Overexposure to noise remains a widespread and serious health hazard in the U.S. service providing and goods producing industries. Excessive noise can lead to poor verbal communication and reduce the ability to recognize warning signals. These dangerous work conditions can also cause stress and fatigue. Occupational hearing loss is a permanent illness, with no recovery currently possible. Method: National Institute for Occupational Safety and Health (NIOSH) has recognized Noise Induced Hearing Loss (NIHL) as one of the ten leading work related diseases and injuries in the United States, and has emphasized its importance as one of the critical areas expressed in the National Occupational Research Agenda. Results: One of the most serious noise problems in the goods producing industries is the operation of continuous mining machines during underground coal mining. In order to minimize occupational hearing loss, noise hazards are “designed out” early in the design process. NIOSH is leading a national initiative called Prevention through Design (PTD) to promote this concept. This paper describes the quiet by design approach of a noise control that reduced noise exposures of continuous mining machine operators by 3dB(A) using the four functional areas of PTD, namely Practice, Policy, Research, and Education.

By A. Salmoni, E. K. Gillin, T. Eger, A. Cann, P. Vi, M. Hunt

Kittusamy (Kittusamy & Buchholz, 2004) state that there have been few studies conducted to assess exposure to whole-body vibration (WBV) in the construction industry. They suggest that there is very little reliable data from the construction industry that characterizes exposure levels to various hazards including WBV or the health outcomes from such exposure and that there is a need for more exposure data. In a recent exploratory study of heavy construction equipment Cann (Cann, Salmoni, Vi, & Eger, 2003) looked at vibration levels for 14 different types of construction equipment. Eight of the 14 pieces of equipment tested exposed operators to levels of WBV that exceeded the recommended limits for an 8-hour period when comparing the measured VDV to the ISO 2631-1 standards. The purpose of the present research was not only to test a larger number of scrapers but also to investigate scraper operator exposure to whole body vibration (WBV) separately for each task. Methods 33 scrapers were evaluated for WBV in a variety of residential and road construction projects. Testing equipment consisted of triaxial accelerometers that allowed vibration data collection in all three orthogonal axes, with the x-axis positioned to measure vibration in the anterior-posterior direction, the y-axis in the medial-lateral direction, and the z-axis in the vertical direction. Root mean square accelerations (aRMS), vibration dose value (VDV), crest factor, and maximum transient vibration values (MTVV) were derived from this software and exported to an Excel™ spreadsheet for later data analysis. Test sessions for each piece of equipment lasted for approximately 20 minutes until at least three work cycles had been completed. Tasks included: idling while waiting for a bulldozer to push the scraper through the scraping phase, scraping, traveling loaded with dirt, dumping and traveling empty. Results Task breakdown by time reveals 25% of the work cycle was spent traveling fully loaded with dirt, 19% dumping, 21% traveling unloaded, 17% idling and 18% scraping. Calculation of aRMS vector sums gave values of 2.55 m/s2 during loaded transport, 2.46 m/s2 during dumping, 2.31 m/s2 during unloaded travel, 0.55 m/s2 during idling and 1.46 m/s2 during scraping (see Table 1). The highest acceleration values recorded were found in the z-axis during fully loaded transport reaching an average aRMS over three work cycles of 2.55 m/s2.

Jan 6, 2006

By Rudy J. Matetic

The National Institute for Occupational Safety and Health (NIOSH) at the Pittsburgh Research Laboratory (PRL) is conducting research to reduce the noise exposures of roof bolting machine operators and to prevent additional cases of Noise Induced Hearing Loss (NIHL) thru the development of engineering noise controls. This paper describes and evaluates an engineering noise control for the roof bolting machine, namely the collapsible drill steel enclosure. The results of the evaluation demonstrated that using the collapsible drill steel enclosure provided a 7 dB(A) reduction in sound pressure level at the operator?s position of a roof bolting machine.

Jan 1, 2008

By Douglas Ketcham, Thomas Jetzer

While the neurological and vascular aspects of Hand-Arm Vibration Syndrome (HAVS) has been generally accepted as a medical condition, the medical criteria and the clinical findings used to establish the diagnosis has been more difficult to bring to consensus. The criteria was first quantified by the Taylor-Palmear scale.1 This criteria was subsequently modified in 1986 at the 1st Stockholm Workshop2,3 to included more acceptance for the neurological effects that characterized the predominate findings in some workers. The relationship between hand-arm vibration and Carpal Tunnel Syndrome was defined in NIOSH 97-1414. While the aforementioned documents have defined the clinical entities associated with hand-arm vibration exposure, agreement on the clinical findings and test to confirm the diagnosis has be been more difficult to bring to consensus. Clinicians assessing HAVS has relied on a number of varied neurological and vascular tests. The neurological testing has focused on assessing damage to the sensory capability of the fingers for the neurological component including tests to measuring ability to sense vibration, cold or other end point finger sensor functions. However, the vascular testing has been traditionally focused on the ability to either measure vascular function or to reproduce the vascular blanching that occurs in HAVS with cold water provocation. Recent assessment of this testing in the United Kingdom Coal Miner’s study has questioned the value of this testing especially in reviews by McGeoch.5 In an attempt to provide some type of definitive testing to substantiate vascular damage from hand-arm vibration exposure, angiography is an alternative or adjunct to cold water provocation testing. The standards that have been established to predict the level, type and incidence of HAVS have been based on clinical studies and reports that have essentially been all male populations. However, the recent entry of women into more vibration intensive jobs has brought about the exposure of some women to high levels of vibration previously only previously experienced by men. However, there have been only few studies that look at HAVS in women6. Although exposed the same vibration levels, it has not been clear that the latency and type of pathology of HAVS in women will be the same as for men. The purpose of this study is to look at recent case studies of men and women exposed to jobs with high levels of hand-arm vibration with extensive clinical testing for both the neurological and vascular components of HAVS as well as other associated upper extremity conditions such as Carpal Tunnel Syndrome.

Jan 6, 2006

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Bolivia has been prepared from the best available information in Washington, but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State. SYNOPSIS OF LAW All useful substances of the mineral Kingdom belong originally to the State. The soil and subsoil are regarded as two distinct parts, the latter extending indefinitely in depth (Art. 2). The subsoil is under the dominion of the State, which may either abandon it to common use, grant it gratuitously to the owner of the soil, or alienate it, in return for an annual fee, to any individual or association that applies for it. (Art. 1-3.)

Jan 1, 1929

By N. Kumar Kittusamy

Operators of construction equipment perform various duties at work that expose them to a variety of risk factors that may lead to health problems. A few of the health hazards among operators of construction equipment are: (a) whole-body vibration, (b) awkward postural requirements (including static sitting), (c) dust, (d) noise, (e) temperature extremes, and (f) shift work. It has been suggested that operating engineers (OEs) are exposed to two important risk factors for the development of musculoskeletal disorders: whole-body vibration and non-neutral body postures. Method: This review evaluates selected papers that have studied exposure to whole-body vibration and awkward posture among operators of mobile equipment. There have been only few studies that have specifically examined exposure of these risk factors among operators of construction equipment. Thus other studies from related industry and equipment were reviewed as applicable. Conclusion: In order to better understand whole-body vibration and postural stress among OEs, it is recommended that future studies are needed in evaluating these risk factors among OEs.

Jan 1, 2004

By Robert A. Miller

This computer program determines the price per ton of coal needed to obtain a profit of 12 percent discounted cash flow. From a predetermined equipment and manning list, the program calculates all costs and prints seven tables, Including the equipment and manning tables and the discount cash flow table. Forty-four of the input variables may be readily changed to study their effects upon the final price per ton of coal or upon individual cost items. The method is adaptable for any type of mining and with additions, for beneficiation processes. This program was written in Fortran IV for use on the IBM 11302 and with few modifications can be used on other computers.

Jan 1, 1971