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By Jeffrey Johnson, Carl Sunderman, Ted Williams, Stephen Signer, Douglas Bayer

To measure the loading behavior of friction bolts, researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) installed strain gauges on the interior of friction bolts and developed a battery-powered miniature data acquisition system (MIDAS) that fits inside the hollow portion of the friction bolt. The advantages of this system are that it is protected from face blasts and eliminates the need for external wiring. Laboratory pull-out tests showed that friction bolts installed in a concrete block with resin were loaded to about 1.8 tons/ft of bolt length; bolts installed without resin were loaded to 1.3 tons/ft. Three strain-gauged friction bolts were installed at Hecla Mining Company’s Gold Hunter Mine, Mullan, ID, in the wall or rib of a mechanized cut-and-fill stope. The object of these tests was to establish an installation procedure for the bolt-and-MIDAS combination and to evaluate performance. The stope was advanced in three 15-ft increments and strains induced in the rock bolts by stress changes in the rock were recorded every 30 minutes. The MIDAS proved to be rugged enough to withstand the shock and vibration from nearby (5 ft) face blasting. Data from MIDAS showed that the friction bolt installed with resin was the most sensitive to each face advance. It showed a steady increase in loading to a maximum value of 1000 microstrain. The friction bolt installed without resin showed stick-slip behavior with loads to a maximum of 400 microstrain before the stope was completed.

By George A. Morgan

The production and processing of crude petroleum and natural gas are the dominant economic sectors of the Middle East. Downstream processing of these mineral fuels to petrochemicals and fertilizers is a major investment opportunity. In 1991, the 15 countries that constituted the region accounted for 26 % of world crude petroleum output, 15.3 % of world natural gas plant liquid production, and 4.5 % of world dry natural gas production. Only Cyprus and Lebanon were not crude petroleum producers. Production of these mineral fuels all declined from that of 1990 owing to the Persian Gulf War, during which output from Kuwait and Iraq either ceased owing to war damage, or was embargoed. Prior to the war, Iraq and Kuwait were the fourth and fifth largest world producers of crude petroleum, respectively. In the war, virtually all of Kuwait's production and transport facilities were destroyed or damaged. Iraq's output was embargoed from export, with only domestic sales taking place. The embargo also affected Jordan, both in terms of transshipment of materials through it to Iraq and in exports of phosphate and potash. Shipments of crude petroleum by pipeline from Iraq through Saudi Arabia and Turkey and by vessel through the Persian Gulf were terminated. However, the loss in production from Iraq and Kuwait was made up by accelerated output from other Middle East and world producers. Saudi Arabia, in particular, with its excess production capacity, accounted for the largest portion, increasing crude petroleum output by 27 % to almost 3 billion barrels.

Jan 1, 1993

By James Rowland

On June 1, 2004, the underground coal mine ventilation safety standards under the Code of Federal Regulations (Title 30, Part 75) became effective for the use of a conveyor belt entry as an intake air course to ventilate working sections. These standards, also known as the Belt Air Rule, contained a section which limited the air velocity in the conveyor belt entry to no greater than 500 feet per minute unless otherwise approved by the US Mine Safety and Health Administration in the fire suppression system section of a mine?s ventilation plan. The Belt Air Rule included a requirement dictating compatibility of air velocity with fire suppression systems. The final rule of limiting air velocity in the belt entry was challenged in the Court of Appeals for the District of Columbia Circuit. The court granted that petition and vacated the requirement on the air velocity cap, according to MSHA. The removal of the air velocity cap from the final rule, paired with the compatibility requirement, led to a need for research on high air velocity?s influence on fire suppression system performance in belt entries. Test data was needed that illustrated the relationship between fire suppression system performance and air velocity, especially with the increased use of wider belts in underground coal mines, so National Institute for Occupational Safety and Health and MSHA collaborated to obtain the data. However, this work was initiated before the revised Belt Air Rule was promulgated on December 31, 2008, when 1000 fpm air velocity became a requirement. Four different

Jan 1, 2009

By Maria I. De Rosa

Table 55 and figure 19 show the number of fires and fire injuries for stone mills by state during 1990-2001. Table 55 also shows the injury risk rates, employees' working hours, and lost workdays. In all, 118 fires occurred in 33 states. Seventy-six of the fires caused 82 injuries (including 8 fires and 6 injuries involving contractors). The yearly average was 9.8 fires and 6.8 injuries. The Ewhr value was 873 x 106 hr (In = 0.019), and the LWD value was 1,911. Missouri had the most fires (16 fires and 9 injuries), followed by Pennsylvania (15 fires and 14 injuries), Michigan (9 fires and 5 injuries), and Virginia (7 fires and 5 injuries). Of these states, Virginia had the highest injury risk rate value (In = 0.09 1). Table 56, partly illustrated in figure 20, shows the number of fires, fire injuries, risk rates, employees' working hours, and lost workdays by time period. The number of fires and fire injuries decreased during most of the periods, with a sharp increase during the last period. The number of employees' working hours increased throughout the periods. The In values follow patterns similar to those shown by the injury values. Tables 57-63 show the number of fires by ignition source, method of detection and suppression, equipment involved, location, and burning material by time period. Figure 21 shows the major variables related to fires for 1990-2001. Table 63 shows the fire injuries per number of fires causing injuries and total fires by year, ignition source, equipment involved, and location.

Jan 1, 2004

Reduce rockfall fatalities and injuries by using innovative blasting practices to reduce damage to the rock at the excavation limits with little or no increase in cost. The Problem Falls of highwall have been a leading cause of fatalities, injuries, and equipment damage in the surface mining industry. Although the number of highwall falls is not great, when such an incident does occur it is about 14 times more likely to be fatal or result in severe injury and damage to equipment than other types of surface mine accidents. Overbreak or damage to the rock from poor or improper blasting practices is a major factor contributing to rock falls. Presplitting or cushion blasting is the technique most often recommended for improved wall control. This type of blasting however, adds to drilling and blasting costs and is not universally accepted by the industry. Air gap presplitting techniques, also called air decks, are currently being used in some mines as a less costly alternative to conventional presplitting. Approach Blasting can cause highwall damage, but proper blasting techniques have been shown to reduce the magnitude of rockfall problems. In preventing rock falls, it is important to maintain the natural strength of the rock structure to the greatest extent possible. Improved blasting practices have three main advantages: 1) they are preventive rather than corrective in nature; 2) they are cost effective; and 3) they have a very low impact on the mining operation when properly implemented. New ways of evaluating highwall integrity, such as seismic refraction tomography, were investigated.

Jan 1, 1991

By Heather N. Dougherty

In the absence of values for each influencing parameter and a known relationship of input-output space, novel approaches should be implemented as proxy solutions to mathematically complicated problems. Proxy solutions can be in the form of linear or non-linear multiple regression equations. Predicting the performance of gob gas ventholes is one of these mathematically complicated problems as it is difficult to know the exact relationships between various parameters influencing gob gas venthole (GGV) performance from active and sealed (completed) longwall panels. In this paper, a discussion of the NIOSH-developed software suite for methane control and prediction (MCP) based on an artificial neural network (ANN) is presented. The application of the ANN-based software suite to develop algebraic relationships for gob gas venthole performance prediction in sealed and active longwall panels is sought. Output information obtained from the NIOSH-MCP software as a response to various input parameters were used to create an input-output database for total flow and methane percentage from GGVs operating in active mines during completed and sealed panel situations. Due to the multi-variable nature of the software, outputs generated using the software for various inputs were used to develop analytical equations first using linear and then second using non-linear multivariable regression techniques. The advantage of this method is its ability to better understand the significant parameters of the relationships between the inputs and outputs for gob gas venthole production in active and sealed panels and to be able to predict their performances using relatively simple analytical functions.

Jan 1, 2010

This chapter focuses on smoke as it relates to escape from underground mine fires. Among the topics discussed are the measurement of visibility in smoke; smoke-related hazards such as the production of CO, hydrochloric acid (HCI), or other byproducts of combustion; and miners' personal experiences while escaping through smoke. Smoke Measurement and Visibility In general, smoke consists of hundreds of thousands of very small particles. These particles have some "size," usually expressed in terms of their diameters, and they have some concentrations, usually expressed either in the number of these particles per unit volume or the total mass of the particles per unit volume. Humans cannot see individual smoke particles because they are too small. Similarly, "umber concentrations" and "mass concentrations" of smoke particles do not have much meaning to people unless they are trained technically. Still, individuals know that they can see smoke, independent of all the technical jargon used to describe it. Also, they know that when the smoke level gets too high, it is no longer visible. In fact, nothing is visible because the smoke absorbs all of the light in its surroundings. The eye is only sensitive to light in the wavelength region from about 400 nm to about 700 nm. The maximum sensitivity of the human eye is to light that has a wavelength of about 555 nm. It is important to know how the eye responds to light because if its response is known, it is possible to use a light detector that has almost the same response as the eye. Such a detector can then be used to quantify the visible characteristics of smoke because it responds in the same manner as the human eye. Smoke is visible because it either scatters or attenuates (diminishes) light. In some instances, smoke is visible because the smoke particles reflect light which is then detected by the eye. The eye actually "sees" an intensity of light that has been reflected from a cloud of smoke particles. Imagine shining a flashlight into a cloud of smoke. Someone off to the side can actually "see" the beam of light as it traverses the smoke cloud. This is called scattering. Smoke is also visible be¬cause it attenuates light. Imagine having someone shine a flashlight into your eyes. As smoke begins to build up along the beam of the flashlight, the light begins to dim. The smoke is visible because it is now reducing the intensity of light that falls upon the eye. As the smoke level increases, it is said to obscure our visibility. When the beam is no longer visible, the smoke obscuration is said to be 100%. In other words, none of the light energy from the flashlight makes its way through the cloud of smoke. Another way of saying that the obscuration is 100% is to say that the transmission of light through the cloud is zero.

Jan 1, 2000

By Joseph Cervik, Gerald L. Finfinger

This Bureau of Mines publication reviews underground methane drainage pro- grams being conducted in various coalbeds. Equipment used in drainage programs such as drills, underground pipelines, and methane monitoring systems is described.

Jan 1, 1980

By Paul S. Goodman

This report examines the effectiveness of bonus plans in the coal industry. The analysis uses theoretical, literature review and empirical approaches to determine the impact of bonus plans on safety and productivity in underground coal mines. The basic finding is that the modal bonus plan in underground coal mining does not have a major impact on productivity and safety indicators. The design of the plan, or organizational factors, and the process of introducing the plan all contribute to its relative ineffectiveness. Strategies and options for designing effective plans are presented.

Jan 1, 1987

By McHenry Mosier

This paper constitutes the third progress report on a national survey of the use of detachable bits in metal mines. It presents comparative costs of drilling with conventional and detachable bits and describes the operating practice in rock drilling and the reconditioning of drill steel and bits at 10 mines not discussed in previous reports.3/ ACKNOWLEDGMENTS This report has been prepared with the assistance and cooperation of the officials and staff members at the mines visited. Costs and other data at individual mines were developed and furnished by the operators.

Jan 1, 1937

By A. K. Schellinger

1. In the United States, the industrial application of centrifugal force for separating phase constituents has been confined almost entirely to aqueous systems at room temperature. This paper presents results for experimental tests on the use of centrifugal force for separating the liquid and solid phases in molten nonferrous alloys. 2. The development and use of a small centrifuge for treating molten metals is described. The centrifugal apparatus was, in essence, a 3-inch diameter spinner pot, which revolved, within -a gas -fired furnace, at speeds up to 3,000 r.p.m.

Jan 1, 1953

By C. M. McKinney

Bureau of Mines routine crude-oil analyses of 42 samples from 37 fields in the major producing areas in Mexico are presented in this report. Table 1 includes information on the source and general characteristics of each sample. Table 2 gives a summary of analytical and computed data. A map (fig. 1) shows approximately where the samples were obtained. ACKNOWLEDGMENTS Grateful acknowledgment is made to Alfonso Barnetche, manager of production, and Ing. Francisco Inguanzo, assistant manager of production, both of Petroleos Mexicanos, who supplied the crude-oil samples and furnished information concerning their sources.

Jan 1, 1960

By Joe H. Skidmore

This paper, describing mining and milling methods and costs at the Gold Hill mine, is one of a series being published by the Bureau of Mines. Boise Basin, in which the geld Hill mine is located, is in the central part of Boise County, Idaho, about 30 miles by air line northeast of Boise. The mine, owned and operated by Talache Mines, Inc., is at the southern end of the town of Quartzburg. About 115 to 125 tons daily is mind by square-setting and is treated in an amalgamation plant.

Jan 1, 1938

By Erie C. Donaldson

Gas-displacement tests were made in Berea Sandstone and Arbuckle Lime-stone cores to determine the relative permeabilities to gas, oil, and water for two-and three-phase dynamic systems. Three-phase relative permeabilities were obtained by displacing oil and water from the core with gas and measuring the flow rates of the three fluids simultaneously. It was found that relative permeabilities to fluids in a porous medium are affected by the saturation distributions of other fluids in the medium as well as by their own saturation distributions.

Jan 1, 1966

By Robert P. Vinson

This report describes three coal mine ventilation studies by the Bureau of Mines in which sulfur hexafluoride (SF6) was used as a tracer gas. One of these studies was conducted to determine air movement and leakage in a sealed area. Another was run to determine the ventilation efficiency of a bleeder system. Finally, a study was made of air leakage across permanent stoppings of parallel intake airways. These studies proved sulfur hexafluoride to be a useful addition to the equipment commonly used in coal mine ventilation analysis.

Jan 1, 1976

By H. F. Yancey

A relatively large proportion of the coal produced in the state or Washington, especially in the coking coal areas is of fine size; hence washing by means of coal-washing tables to reduce the ash content is commonly practiced. For this reason the program of research in coal washing conducted jointly by the U. S. Bureau of mines and the College of Mines, University of Washington, has given special attention to the mechanism of the separation of coal from its impurities as affected by the coal-washing table with the object of

Jan 1, 1931

By R. L. Crosby

A part of the liquidus of the magnesium-zirconium system was determined by chemical analysis of suction samples taken from the melt in the approximate temperature range of 850° to 1,450° C. The melt was prepared in a furnace pressurized with an inert gas. The average zirconium value in weight-percent of the liquidus composition at each sampling temperature was 0.96 at 867° C, 1.40 at 1,062° C, 2.05 at 1,262° C, and 2.96 at 1,402° C. The equilibrium solid phase was zirconium.

Jan 1, 1965

By A. C. Watts, C. A. Allen

In the No. 3 Sunnyside mine of the Utah Fuel Co. a disastrous fire started on the afternoon of August 17 , 1920 , the effects of which are still present in the mine . On account of the extent of the fire , the expense involved in reopening the mine and the opportunities afforded for determining the effects of depleted air , a description of it is worthy of record . This paper is a summary of a more complete report , prepared by the writers , which will be published by the U. S. Bureau of Mines .

Feb 1, 1922

By D. Montagna

This Bureau of Mines report describes a salt-free, fluxless method for reclaiming metallic aluminum from aluminum dross. The dross is smelted under argon, nitrogen, or carbon dioxide, instead of a salt flux, in an externally heated pot furnace. Aluminum recovery, using argon, is equal to recoveries reported from commercial smelters that process dross in rotary-type furnaces This salt-free method could offer a reduction in air pollution, lower energy requirements by elimination of salts, and the production of up to 60 percent less solid waste for disposal than the salt method.

Jan 1, 1978

By McHenry Mosier

This paper is one of a series recently undertaken by the Mining Branch of the Bureau of Mines to describe current practice in diamond drilling for production at various mines throughout the United States and to discuss the relative merits of this method compared with drilling by percussion rock drills . The Bureau of Mines and the mining companies that are cooperating with it in this ' investigation have the objective of developing information on diamond -drilling blast holes for the benefit of all who are interested in the possible improvement of mining operations .

May 1, 1947