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Develop a safer, more effective, and more efficient method to control fires in abandoned coal mines and waste banks. Maintain the costs of this new method at less than or comparable to conventional AMI fire control methods. How It Works Cryogenic extinguishment of subsurface fires is a method of heat transfer. Bureau-designed injection equipment produces a pumpable slurry of liquid nitrogen and solid particles of carbon dioxide. Liquid or gaseous carbon dioxide from a pressurized tank flows to a bell-shaped nozzle where the change in pressure causes the carbon dioxide to form a granular snow. The solid carbon dioxide is mixed with liquid nitrogen. A jet pump is used to move the slurry through the delivery lines and into a simple injection probe. At injection, the nitrogen vaporizes and the carbon dioxide sublimes. This phase change produces a cold gas (-180° C) that, as it expands and moves in all directions, removes heat and also displaces oxygen. This combined process inhibits the combustion process and lowers the temperature below the reignition point. When the liquid nitrogen and solid carbon dioxide are converted to gases, the expanding gas acts like a piston, forcing warm air out of the porous bed, Although smoke and hot gases arc forced from the burning coal, generally there is no significant increase in the odor associated with burning coal.

Jan 1, 1992

By A. M. Dale, J. Standeven, B. Evanoff

Tool manufacturers continue to incorporate new designs to the internal mechanism of tools in order to decrease the vibration that is delivered to the hand during operation. Modification of some tools to minimize tool vibration is not easily resolved through internal tool design. For this reason, vibration damping materials applied between the tool and the hand are a simple alternative. The damping materials may be applied to the area of the tool directly contacted by the operator or in a glove containing a vibration absorbing pad. These interventions are developed specifically to damp vibration but are not necessarily produced and tested under the same work conditions that a company may expose their workers. Therefore, it is important to test the value of the proposed interventions for the specific applications. This study evaluates the effectiveness of anti-vibration interventions currently in use at a local manufacturing company. Methods The design of this study evaluates the vibration energy produced at the tool handle and from the back of the operator’s hand. Each operator performed a series of fastener installations in metal using several interventions and one series with no intervention as a control. Four of the interventions were gloves containing anti-vibration material and the fifth intervention was an anti-vibration material wrapped around the tool handle. The protocol for wrapping the tool handle was developed and is part of the equipment procedure at this manufacturing company. Test conditions mimicked production work conditions including similar materials, fasteners and technique for installation. Vibration values were collected using 3 tri-axial accelerometers with one firmly glued to the tool handle close the hand grip as recommended by ISO 5349. A second accelerometer was placed on the top of the pistol shaped tool. The third accelerometer was attached to the back of the hand close to the third knuckle using double sided tape. Results Preliminary results for 3 volunteers show a difference between the vibration values of the control condition (mean hand vibration on bare hand = 1.77 Gs) compared to all of the interventions (p=.0001 using Mixed Procedure, Tests of Fixed Effects). The graph below shows individual trials for each subject for each condition. Glove 3 with the air bladder insert shows large variability between subjects (Range = 0.84-3.33 Gs). The other interventions show much less variability both within subjects and between subjects indicating consistent response with use of the intervention.

Jan 6, 2006

By David Cooper, Susan Robertson, William Wiehagen, Launa Mallett, Charles Vaught, Joan Dickerson, Richard Conkle, ROBERT PETERS, Mike Brnich, Charles Urban

This trainer’s guide is designed as a reference manual. The purpose is to offer information and examples to skills trainers to assist them in structuring training for new operators of Walk-Thru roof bolting machines. Trainers can use this manual as a resource for helping trainees learn, understand, and apply knowledge and skills. In this sense, the guide is not prescriptive. It is designed to offer information and trigger ideas on what might be done to accelerate learning to those who are new to the roof-bolting task. On-site trainers can modify this guide to fit their conditions, machines and equipment, and work procedures. They can integrate roof control plans, company policies and procedures, and operators’ manuals from the manufacturers of the original equipment into this guide. Every trainee is different and will come to the job with varying levels of relevant knowledge and skills. The trainer’s decisions on where to start, how to organize the on-the-job and classroom training portions, and when and how to offer different aspects of the training will be based on (1) a pretraining assessment of the trainee’s knowledge and skills and (2) the trainer’s experience in conducting skills training. The “Skill Check” section might be useful for deciding where training should start among miners who have underground experience but limited knowledge of roof-bolting techniques. Every job carries a learning curve and likely has a number of “teachable moments” where significantly new knowledge and skills can be learned. The videos on the DVD that accompany this guide can be shown at the beginning of training to give trainees an idea of what the job entails and related requirements. They can also be used within the training cycle (after the trainee has some experience in the job) to reinforce key points or as a trigger for eliciting questions about particularly difficult parts of the job. The video segments are meant to be visual models of good performance. They are designed to elicit discussion on good (lower risk) ways to do the job. In this context, they can be used very creatively at different times within the training cycle. The section on “Talking Points” offers a number of questions that can be used in the classroom to support and elaborate on certain aspects of the job duties. If the trainee has a fair amount of underground experience, some of the questions can also be used to support the pretraining assessment (i.e., skill check) of knowledge and skills. Likewise, some of the questions can also be used while teaching on the job to reinforce key points affecting safety, production, or maintenance. The section dealing with a mine’s roof control plan should be used at various times in the training cycle to make sure the trainee understands the plan and knows how to apply it in performing the job. The supplemental materials offer additional resources that can be used to support initial job training or follow-up. Learning continues well after an individual has been trained. The supplemental materials can help reinforce good operating skills and provide an opportunity for further discussion on better ways to do the job.

Jan 8, 2006

By A. R. Mumford

The fuel economy ot a. plant m be better than ite anxious friend.a J'ealize. A watchful a-aper1.ntend.ent of a Goverment plant, kn.owing that improvements in plant equipment bad. been made since hie atOkel'e were installed, was almosi per­ suaded to aubatitute a new t.,pe. The Bul'eau. of Mines was asked to aaoertain the a.cti.i&l performance ot the old stokera and tound. the plant alr doing from three to five per cent better than was promieed for the new egp.ipment. Tbe va.1.ue ot accurate knowledge of plant perfoimarice, am the need. ot eqm.pment to weigh and measure quantities is thus demonstrated. The boiler and ,tour ett1c1enc, was found to be 75 per cent, and the overall efficiency of the boiler, etoker• and economize, wae 78 per cent. Both records are high, and are to be attributed to ce in operation, to good working condition of the plant, and to the low rate ot evaporation, which was only aboui two-third., et the botler'e rated. capacity. The plant teated conaiated ot two la.boock & Wilcox boiler, tired b1 means of over teed 1toker1 and equipped wi t,b. a fuel economiaei- 1n the uptake. The bo1lel'a ,upplied ateam to two large water pump being used only intermittently.

Jul 1, 1922

By M. Gottlieb, P. Metes, Charles Sabine, Louis J. Denes, B. Kaminsky, Jami M. Girard, Ronald T. Mayerle

A significant risk factor in assessing and modeling potential catastrophic slope movement in open-pit mines is the presence of argillic alteration in host rocks. High-resolution hyperspectral imagery operating in the visible to shortwave infrared can be a useful tool for identifying and mapping potentially dangerous argillic zones. We have conducted preliminary experiments with a new type of hyperspectral imager that employs an acousto-optic tunable filter, a variable retardation plate and a standard digital camera. The instrument we tested operates in the .5-1.0 micrometer range. A shortwave infrared instrument is planned, and mid-infrared instruments have been designed. An AOTF consists of an acoustic transducer that generates an acoustic wave that propagates through an attached crystalline substance. The wave sinusoidally modulates the refractive index of the crystal, selectively diffracting incident light according to its wavelength. The instrument also measures polarization signatures of reflecting surfaces as well as their spectral properties, opening up new areas of possible research. Images can be acquired and processed at 30 frames/second. The AOTF camera system offers numerous advantages to geologists. It can be used as an airborne imager or as a portable field device to image pit walls, outcrops, rock specimens or drill core. It can be adapted to image polished sections under a microscope, and it could be used in underground workings. Algorithms can produce processed images in real time (e.g., ratio images), and, because it is a camera system, aerial images can be orthorectified.

By Stuart R. Zimmerley, John Gross

"In the study of ball-mill grinding at the Intermountain Experiment Station of the United States Bureau of Mines at Salt Lake City, Utah, it was desirable to measure the work input to a ball mill at the mill itself so that consideration of motor efficiency and transmission losses would be eliminated.The device adopted is essentially that used by Prof. H. E. T. Haultain4 in measuring work input to rolls. The mechanism was changed only so as to adapt it to a ball mill.Figure 1 is a diagrammatic sketch of the apparatus.The pulley which rotates the mill is loose on the mill shaft and is equipped with ball bearings. This pulley is connected by means of three tangential springs to the driving plate, which is solid on the mill shaft. Power applied to the loose pulley is transmitted to the driving plate, and hence to the mill, by the three springs; the greater the resistance of the mill, the greater the spring extension. The extension of the springs is transmitted by the steel extension tape to the differential integrating meter.The integrating meter is operated by two friction wheels in contact with the integrator disk which revolves at a definite ratio of speed to that of the mill. The friction wheels are held in contact with the disk by the spring suspension of the integrator and are connected to a differential gear cage, the revolutions of which are recorded on a counter such as is used in gas meters. Due to the differential gears the c e is stationary when the two friction wheels revolve at the same speed in opposite directions; this condition exists when the integrator is centered on the disk and corresponds to no load or to a zero spring extension. As the lead is applied, the springs extend and move the integrator from the center or zero point, resulting in a difference of speed between the two friction wheels. Due to the revolution of the differential cage this change in. speed is transmitted to the counter. The integrator and extension tape system is kept taut by means of a light spring attached to the integrator, the spring having just enough tension to assure that the integrator returns to zero when the load becomes zero."

Feb 1, 1931

By Charles Vaught, Belinda Sue Mills, Henry P. Cole, William J. Wiehagen

This study reports the results of a survey of organizations that used problem-solving simulation exercises to support mine health and safety training. The exercises are designed to teach judgment and decision-making skills within two broad domains: (1) how miners respond to mine emergencies (e.g., first aid, self-rescue, and escape) and (2) how miners integrate safety concepts within the context and performance of routine production work. The simulation exercises were distributed by the Mine Safety and Health Administration's National Mine Health and Safety Academy near Beckley, WV. The present study focused on those organizations that ordered the exercises from the Academy over a 2-year period (1995-96). Researchers assessed how the materials were used and trainer perceptions of the impact of these materials on annual mine health and safety training . A total of 147 organizations ordered the exercises over the 2-year period. Survey responses were obtained from 52 of these organizations. Sixty percent of the respondents rated the exercises as more useful than traditional instructional materials, 40% as equally useful, and 0% as less useful. Most trainers (79%) felt that the exercises help them to make better use of workers’ knowledge and experience during training. Many (71%)also reported that the simulations helped to improve the effectiveness of their instruction and promoted a problem-solving approach to their training. Fifty of the fifty-two respondents reported that they would like to have new simulations developed. A large majority showed a proactive interest in helping to develop and field test new exercises. Ninety-four percent of the trainers judged the exercises as a good value; 92% planned to order more simulations in the future. Based on this study, recommendations are offered for the continuation and expansion of simulation exercises as one method for occupational health and safety training.

Jan 1, 2001

By A. A. Berk

In the course of a study of the formation of external deposits on tubes in water-tube boilers it became desirable to determine the sulfur dioxide (SO2) and sulfur trioxide (SO3) in the Due gases. Determinations made by the A.S.M.E. method for SO2 and SO3 in gaseous products of combustion did not give accurate results. It was found that minute quantities of copper, present in the flue gases from the coal in use, caused oxidation of sulfite in the absorption bottle and that the carbon dioxide (CO2) in the flue gases caused high values for SO2. The A.S.M.E. test procedure was revised to prevent oxidation of sulfite in the absorption bottle and to allow for the effect of CO2; subsequent analyses of flue gases produced reliable results. The revised procedure is described.

Jan 1, 1950

By Michael J. Magyar

This report contains a cost estimate of the Bureau of Mines process for dewatering Alaskan placer effluent streams with polyethylene oxide (PEO). In this process effluent slurry is withdrawn from the placer plant pond system after a primary settling stage. A dilute PEO solution is injected into the slurry line to flocculate the fine, suspended solids. The flocculated solids are dewatered on a stationary screen. Clarified water is returned to the placer operation or discharged, while the 35 percent solids waste is pumped back into the mine cut. Cost estimates are presented for dewatering plants processing 1,000 gallons per minute of effluent slurry at three representative turbidity levels. Both the placer and the dewatering plants operate on the same 1-shift-per-day, 6-day-per-week schedule for the 100-day Alaskan operating season. Estimated fixed capital costs for these plants processing placer with effluent turbidities of 1,000, 3,000, and 5,000 nephelometric turbidity units (NTU) are approximately $29,000, $31,000, and $34,000, respectively, on a fourth quarter 1986 basis. Operating costs are estimated to be $0.34, $0.37, and $0.40 per thousand gallons of effluent slurry.

Jan 1, 1987

Reduce injuries caused by slips and falls from large haulage vehicles. Approach Replace the flexible-cable or chain-type lower ladder steps, with steps that extend closer to the ground and do not sway when stepped on. Modify dimensions of entire ladder to new industry recommendations. How It Works New lower ladder steps are supported by side pieces made of pretensioned, solid-wound, coil springs fabricated from high strength steel. Unlike conventional crash-resistant steps, which flex or swing freely when stepped on, the spring supported steps can maintain the same inclination as the fixed upper portion of the ladder while supporting an average-weight operator. The steps are also highly resistant to collision damage because they yield on impact if rammed into obstructions such as rocks or berms. See photograph.

Jan 1, 1980

By M. C. Simmons, Boyd Gutorie

Desulfurization experiments at the Petroleum Experiment Station of the Bureau of Mines at Bartlesville on virgin light distillates obtained from some ‘high-sulfur’ crude oils have shown that the octane numbers of the original distillates are increased on the average about one unit, that the octane numbers of distillates with 4 ml. tetraethyl lead are increased 2 to 3 units, and that the The Petroleum Experiment Station, at the request of the Petroleum Administration for War, instigated and has in progress an investigation of crude oils of the United States to determine their possibilities for yielding straight-run distillates suitable for use as base or blending stocks to produce high octane aviation gasoline. One phase of this investigation deals primarily with so-called ‘high-sulfur’ or ‘sour’ crude oils by seeking to determine the effects of sulfur removal upon the virgin distillates prepared from these crude oils. To date, virgin distillates from several ‘high-sulfur’ crude oils from Texas, New Mexico, and Oklahoma have been prepared and desulfurized in pilot-plant distillation and desulfurization units at the Petroleum Experiment Station. The properties of the undesulfurized and desulfurized distillates were determined and compared to show the effect of sulfur removal. Results of these investigations showing the suitability of these crude oils as sources of virgin naphtha aviation base stocks have been prepared and forwarded to the Petroleum Administration for War and other approved persons. The following preliminary summary is presented to acquaint those interested not only with the present results of the investigation of several ‘high-sulfur’ Texas, New Mexico, and Oklahoma crude oils, but also to give some basic information as to certain sulfur compounds, especially their identification in straight-run distillates, their depressing effects upon the octane numbers of leaded fuels, the benefits obtained by their partial and complete removal, and some of the processes being used to effect their removal.

Nov 1, 1943

By L. B. Pankratz

The heat content above 298.15° K was determined for crystalline vanadium silicide of the composition V3Si. This substance has a minor thermal anomaly (probably a heat-capacity maximum) near 560° K; the extra heat absorption is about 50 cal/mole. The original heat-content data are presented, and smooth values of the heat content and the corresponding entropy increments are listed for the temperature range from 298.15° to 1,500° K. Equations representing the heat- content values and derived heat capacities are also included.

Jan 1, 1963

By H. W. Wainwright

One phase of the research and development work on synthetic liquid fuels conducted by the Bureau of Mines at Morgantown, W. Va. in cooperation with West Virginia University deals with the purification of synthesis gas.2/ Most of the experimental studies on gas purification have been directed toward the removal of organic sulfur from gas, either catalytically or by adsorption with activated carbon. An important part of the purification program has been the development of suitable analytical methods for determining organic sulfur compounds. As the total sulfur content, organic and inorganic, of purified synthesis gas should not exceed 0.1 grain per 100 cubic feet, the need for accurate analytical methods is apparent. It is also apparent that such methods must be rapid if one wishes to evaluate various processes for removing sulfur from gas. The organic sulfur found in most gas produced from coal is usually present as carbon disulfide, carbon oxysulfide, methyl and ethyl mercaptans, and thiophene, with the exception of thiophene, the remaining organic sulfur compounds respond similarly to catalytic treatment and can be removed effectively. Not only does thiophene resist most catalytic treatment, but it poisons some catalysts, rendering them ineffective in removing the other forms of organic sulfur.

Jan 1, 1950

By Michael D. Fenton

The very modest-sized mineral industry of Afghanistan was burdened for another year with problems of internal strife occassioned by the presence of Soviet armed forces. Despite this, production of the few traditional commodities continued, and the mineral industry moved to develop additional mines and plants for both traditional and new products with considerable technical and construction assistance from the U.S.S.R. Among the limited range of mineral commodities for which production was reported, there were no startling changes between 1984 and 1985. Production of both coal and natural gas advanced only slightly, despite substantially higher 5-year plan goals, and cement output was down marginally. Probably the most significant development in 1985 was the Possibility that mine and/or smelter production of copper was initiated during the year.

Jan 1, 1987

By J. W. Horne

The United States Bureau of Mines in cooperation with the State of Colorado at the University of Colorado has conducted experiments to determine the amount and composition of the noncondensable cases evolved when crude shale oil is distilled under pressure. Hydrogen sulphide is one of the components found in the complex mixture of uses produced by the distillation of shale oil under pressure. This paper deals with the apparatus and method used in determining the amount of hydrogen sulphide evolved in the laboratory experimental cracking stills.

Jan 1, 1931

By D. B. Taliaferro

An accurate knowledge of the water content of oil-bearing sands4/ now is recognized as an important factor in calculations of the flow of oil through the sands to producing wells and in the estimation of oil reserves. To this end the Bureau of Mines laboratories are using a method that is an adaptation of the A. S. T. M. method of determining the water content of petroleum products (1).5/ However, the apparatus and technique have been altered slightly, as described in this report, to increase the precision of the method without affecting the simplicity of procedure or speed with which determinations may be made. Until recently petroleum engineers, when estimating reserves assumed that the entire pore volume of the oil-saturated parts of producing sands was filled with oil, as it was generally thought that the oil, water, and gas in any formation had separated completely during geologic time into distinct layers because of their difference in density. In 1929 Lindthrop and Nickolaeff (12) reported experimental results from which they concluded that 22 to 30 percent of the pore volume of producing sands in the Grozay district, Russia, was filled with water when the fields were discovered. Since that time numerous investigators (5, 7, 8, 10) have found evidence of water in the sands of now oil-producing fields and old fields that never produced water with the oil.

Jan 1, 1940

By P. J. Dallimore

The Bureau of Mines has calculated general time-dependent solutions for radon diffusion from cylindrical and slab rock samples containing uniform radium distribution. Results have been obtained for several sets of boundary conditions. The method is suitable for determining the effective diffusion coefficient and the effective porosity for radon.

Jan 1, 1983

By J. D. Davis

From the chemist's point of view it would be ideal if specifications for coke for any stated purpose could be written on the basis of chemical composition and burning characteristics. Unfortunately this is not possible. In fact, the physical properties of a coke are often of such major importance as to render any specified chemical requirements totally inadequate to show the quality of coke desired. For example, a furnace coke may admirably fill all chemical requirements, such as for low phosphorus, sulphur, moisture, and high fixed carbon, and still be too soft to support the burden of the furnace without excessive crushing. Again, a domestic coke though a good fuel as judged from Chemical analysis, may be of unmarketable size. Thus one can not define the quality of a coke for a specified purpose without taking into account both its chemical and physical characteristics even when this has been done the specification may fail because neither coke user nor producer can accurately define by quantitative tests the qualities most desired. In other words, there is need of accurate test methods for measuring the properties of coke and, what is equally important, for correlating the results with the behavior of the coke in use. Coke quality is determined by the kind of coal used, the coking process, and the type of equipment used in the coking process. Chemical analysis of the coals, together with small-scale coking tests, will give a good indication of their suitability; but, in general, coke must be produced on an industrial scale and tested in the equipment for which it is intended before conclusive information as to its quality is obtained.

Jan 1, 1928

By L. C. IlsLey

As part of its work for the improvement of safety conditions in mines , the Bureau of Mines has undertaken to establish a list of permissible storage - battery locomotives for use in gaseous mines , and , to this end , has issued Schedule 15 , "Procedure for Establishing a List of Permissible Storage -Battery Locomotives for Use in Gaseous Mines . " Up to the present time , two approvals * have been issued under this Schedule , and considerable testing work done on four other applications which have been made for approval . Prior to the publication of Schedule 15 , the Bureau conducted both field and laboratory investigations to determine the hazard from the batteries used in mine locomotives . ** These investigations indicated that the safety of the locomotive would depend largely on proper care of the battery , also on the use of a battery as mechanically rugged as possible . For this reason the Bureau staff , in testing locomotives submitted for approval , considered it advisable to subject the batteries to a jarring or bumping test to prove their adequacy as regards mechanical endurance and ruggedness . These tests on the batteries of the locomotives are described below.

May 1, 1922

Provide a strategy for calculating optimum distribution of selected sensors for detecting underground mine fires. Approach The Bureau of Mines performed research to determine adequate distribution of product-of-combustion (POC) fire sensors within mine entries. This placement strategy would improve the miner's chances for escape by locating sensors where they would most effectively, quickly, and efficiently detect fires resulting from coal or wood combustion. Spacing of Sensors Placement strategy guidelines were based on the performance of 160 F heat sensors with ideal operating characteristics which were placed at intervals of ten feet in underground mine entries. Data obtained from full-scale mine fires were used to estimate fire sizes and alarm activation times for the heat sensors. Various equations were then developed to determine spacing requirements for any fire detection system installed in entries of varying heights, widths, and ventilation rates.

Jan 1, 1983