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By Michael Radnor

The purpose of the study was to 1) examine the social and economic impacts of surface mine blasting in relation to variations in conditions of terrain and geology, population density and type, levels of ground motion and air blast; 2) consider technical, legal and government policy issues; and 3) examine the potential, nature and extent of surface mine blasting impacts and its regulations upon both communities and surface mining companies. Phase One designed the empirical research and technical analyses of Phase Two, focused upon surface coal mining and quarrying in the Eastern U.S. Several broad conclusions are evident: 1) blasting is not the major issue for communities or surface mine companies; 2) while the number of instances of severe cracking or annoyance are relatively small, the impact can be severe for individuals immediately involved; 3) blasting/drilling cost curves tend to rise significantly at intervals below 1.0 particle velocity, in/sec, dependent upon the size of a permit area and the size of a mine; and 4) the legal, complaint, cost and density analyses do not suggest the need for a general lowering of present regulations.

Jan 1, 1981

By R. B. Crookston

Oil shales differ from coals in that they contain less carbonaceous material, convertible to volatile hydrocarbons, and more inorganic rock. In all pre-commercial oil shale development, involving extensive full scale mining operations, there have been no explosions. However, large scale mine tests with oil shale dusts by the Bureau of fines showed that propagating explosions could be induced under certain circumstances. Laboratory tests were conducted on a broad spectrum of oil shale dusts to define chemical properties and to seek correlations with subsequently determined fire and explosivity properties. These latter properties, indicative of safety hazards, increased as the Fischer assay oil yield of the dusts increased and as particle size decreased. Laboratory data were used to relate fire and explosivity properties of oil shales to those of coals and other carbonaceous materials and to assist in the identification and evaluation of potential hazardous situations which may be encountered in oil shale mining and processing.

Jan 1, 1978

By Thomas Varley

During the past few years, since flotation has become the paramount treatment method for most all kinds of ores, the Bureau has gathered the data on consumption of reagents used in the flotation treatment. The first report was issued in 1916. A brief review of such reports snows the progress made in the art of flotation, and each year brings forth the development of new reagent a or combinations of reagents that seem sure to survive, but research and progress spell their defeat, if not by entire elimination, at least subjects them to considerable modification.

Jan 1, 1928

By Francis J. Kelly

This Bureau of Mines study was made to obtain and present facts concerning the production and marketing of rare-earth metals and thorium in the Central and Southern Rocky Mountains (Arizona, Colorado, New Mexico, Utah, and Wyoming, referred to in this report as the region) and to review the current demand for these elements in the United States. Little or no published information was available on the marketing practices for these commodities. As a result of many inquiries from industry, potential prospectors, and the general public, the various factors of resources, production (present and potential), marketing, and consumption have been investigated, and the results are set forth in this report. Material concerning occurrences and deposits is from published references detailed in the bibliography.

Jan 1, 1962

By John J. Sammarco

The U.S. Bureau of Labor Statistics reports that the mining industry has the highest average annual fatality rate (31.9 per 100,000 workers) among all major American industry. To address this, a major research program to reduce hazard exposure of miners with computer-assisted mining equipment was initiated by the U.S. Bureau of Mines.1 One application involves the manual process of extracting and hauling coal where operators, in the tight confines of a mine, can be struck or caught by mobile machinery. The approach to remedy this problem uses a guidance system on the haulage equipment so that it follows the machine that extracts coal. This, in essence, involves sensor-based docking of the machines. Sensors that can survive the hostile mine environment of dust, methane gas, and water, play the key role. Computer analysis of the mining machine's movements and empirical machine characterizations were conducted to establish operating requirements and spatial limitations to ensure proper loading of coal into the haulage equipment. These data served in the selection of a sensing system. Various technologies such as scanning laser systems and ultrasonic sensors have frequently been used in other applications but were found unacceptable. However, a near infrared (IR) sensor employing active targets met the requirements. The sensor has a nominal 75° conical field-of-view and a range from 0.1 to 18.0 m. For the single target mode, nominal range accuracy was 4.3% at a distance of 3.56 m. Correction algorithms were generated reducing the error to 0.6%. Airborne dust testing showed less than 0.8% accuracy (worst case) degradation at levels exceeding (by a factor of 7.5) concentrations permitted by Federal law. The sensor can track multiple active targets providing five degrees-of-freedom (DOF) measurements. Using four targets, the nominal range accuracy was 0.4% without correction algorithms. A guidance system for the haulage system to follow the mining machine does not exist commer¬cially. Such a system can reduce fatalities and injuries by current haulage mining equipment, and is a viable alternative to current haulage control.

By R. D. Leitch

"INTRODUCTION The character of mine drainage from areas of low pyritic coal3 and from average pyritic coal4 has been investigated, and to complete the study it seemed desirable to select a number of mines situated in high pyritic are as to determine whether or not this variation determines the relative acidity of drainage from mines operating in these characteristic coal fields. Advantage has been taken of some worked on in 1918 by Henry Leighton 5, then Professor of Economic Geology, University of Pittsburgh. He visited and has reported certain areas of high pyritic coal which we also visited during this study. Many of the mines were found to be idle in 1930 and a few were caved shut, apparently for several years. However, samples of the outflow from all mines visited were collected if possible and analyzed, and some general information was gathered for each mine. The map (fig. 1) shows the location of these areas as given by Leighton.ACKNOWLEDGMENTSThe information and assistance obtained from officials and others at the mines visited during this study are gratefully acknowledged, as well as the original suggestion from Dr. Glenn V. Brown of the State Sanitary Water Board who called attention to the desirability of such a study.Thanks are also especially due the coal laboratory of the United States Bureau of Mines, under the direction of H. M. Cooper, for the analyses and determination of sulphur forms in the large number of solid samples necessary to the work reported,This study has been carried on under the direction of R. R. Sayers, chief, health and safety branch, and W. P. Yant, supervising engineer, Pittsburgh Experiment Station, of the U. S. Bureau of Mines."

Jan 1, 1932

By V. F. Parry

[Approximatel~r 7-1/2 illion tOlls of subb1tnminous coals are mined an-nuall in Colorado, Wyo~ing, and Montana, of which 50 percent probably reaches dome ,-tic conswno:os. r:L'he moi s t'_re of the se subbi t1.Uninous coal sis high, averae;:t.:ug about 25 :!,)ercent \-Then they are :nined. T'ne coals are non-caking d ~~ack to a vari ble degree when exposed to nornal atmospheric conditions. ~hey a~e gpod domestic fuels, are considered to be smokeless in most furn~ces, and have been used. f, r f!1an: y ars in hand-fired domestic furnaces in hich tnc practice i~ to e~ploy large lureps for efficient com-]

Jan 1, 1941

By P. G. Pigott

This Bureau of Mines laboratory research demonstrated that building bricks meeting ASTM specification C62-66 for grades SW and MW of FBS-type bricks can be produced from waste copper mill tailings. Waste tailings from accumulations at Magna, Utah, Anaconda, Mont., and Hayden, Miami, and San Manuel, Ariz., were dry-pressed into bricks, and the products were tested in accordance with ASTM Designation C67-66 on sampling, and testing of brick. An evaluation derived from pilot-plant production of similar brick at the Coal Research Bureau of West Virginia University indicated the production cost to be about $34 per 1,000 bricks. Utilization of such mill tailings on a commercial scale would eliminate the need for digging new pits for brick raw material production, conserve natural resources, and simultaneously remove potential sources of air pollution.

Jan 1, 1971

By P. B. Altringer

The Federal Bureau of Mines conducted a study to determine if residues from fractional distillation represent a potential source of mineral values. A literature review and discussions with tar sand specialists failed to disclose the mineralogical nature of residues remaining after bitumen extraction. To develop this information, pilot plant tar sand residues or toluene-cleaned tar sands from 23 deposits were examined. The nature of the residues was determined by standard mineralogical methods and the chemical compositions were determined by X-ray and ICP (inductively-coupled plasma spectroscopy). None of the sands or concentrates examined contained sufficient valuable minerals to be economically important.

Jan 1, 1982

By A. Visnapuu

Excessive noise and high vibration are inherently associated with equipment used in the mining, extraction, and processing of mineral resources. High vibration degrades structural components, often leading to catastrophic failure and loss of productivity, and excessive noise can result in permanent hearing loss. In order to foster efficient utilization of the Nation's mineral resources and minimize occupational hazards associated with mineral processing, the Bureau of Mines investigated the relationship between the microstructures of carbon and alloy steels and cast irons and their damping capacities (ability to absorb vibration). Researchers measured damping capacity and other properties and investigated the effects of carburizing, spheroidizing, and annealing. The investigators found that in carbon and alloy steels, rounded colonies of fine-grained pearlite in a ferrite matrix correlate well with low damping capacity. Steel microstructures that exhibit sharp-faceted pearlite in ferrite matrix and partially or fully spheroidized cementite in ferrite show considerably higher damping. In cast irons, the lowest damping capacity is associated with nodular graphite microstructure, and the specific damping capacity (SDC) increases as the graphite micro-structure progresses from nodular to compacted to flake. Predominant ferrite in cast irons is also associated with good damping. SDC data are presented for selected carbon and alloy steels and cast irons.

Jan 1, 1987

By J. Walden, J. Rhoades, R. E. Miller, R. Gibbs, P. Boman

Accelerometers and pressure transducers, mounted in suspension components, can be used to monitor the ride of haulage trucks. Presently, it is difficult to tell what caused a jolt to the truck using either pressure or acceleration data alone. When information from a global positioning system (GPS) is recorded at the same time as shock pressures or acceleration data, the exact location of an event can be determined. Mine management can then determine what caused the jolt to the truck. This research is part of a National Institute for Occupational Safety and Health (NIOSH) project called "Engineering controls for reduction of jolting/jarring injuries in surface mines." NIOSH is investigating how the work environment of haulage truck drivers can be improved. The US Mine Safety and Health Administration (MSHA) notes that, between 1986 and 1995, 60% of the back injuries were to haulage truck drivers in metal/nonmetal surface mining. Personnel from Phelps Dodge suggested that combining acceleration data with information obtained from a GPS could generate results with a variety of uses. Therefore, researchers at the Spokane Research Laboratory (SRL) began investigating how to tie acceleration and GPS data together. It was originally thought that this tool would be used primarily for road and truck maintenance. However, as research progressed, it became apparent that it would also be useful in providing feedback about equipment operations and identifying unusual causes of jolting. Experimental approach Available components that function well by themselves were linked for the purpose of proof of concept. Using a Modular Mining Systems (MMS) product called Vital Signs, SRL researchers took an Aero-Marine Products (AMP) acceleration recorder and hardwired it to MMS Dispatch equipment already installed on a truck. AMP is one of several manufacturers of acceleration recorders frequently used to monitor freight during shipping. MMS Dispatch is used for production accounting and truck dispatching and uses GPS tracking. Through Vital Signs, an analog or digital alarm signal can be recorded. Steve Rhoades, of MMS, wrote unique code that links the Vitals Signs data and GPS location and stores this data in an ASCII log file. SRL researchers installed the equipment in a Caterpillar 793 haul truck. The result was a working prototype. Figures 1 and 2 show the instrument installation in the truck. Discussion From 8:30 pm on Sept. 14, 1998 until 6:50 am on Sept. 15 1998, 899 jolts above a threshold of 2 g (1 g is the acceleration of gravity. It is either 9.81 m/s2 or 32.17 ft/ s2.) were measured on the test truck. Some sections of the haulage road produced most of the events, while

By Harry Dobroski

Communications with moving tracked vehicles in a rail haulage mine pose a difficult problem. These communications take place from dispatcher to vehicles or from vehicle to vehicle via the trolley line, which is a very poor communications line. As a result, deadspots and high-signal areas can occur anywhere along the line, or signal can decrease simply as a function of distance. An analysis is made of the trolley line as a communications line, and methods of improving its characteristics are discussed. Data from inmine experiments are presented, showing actual improvements in communications. Recent Bureau developments in new hardware are also discussed. These include an adaptive speaker control for existing carrier phones and a new generation of improved carrier phones.

By F. R. Lee

[WHEN the Bureau of Mines was established in July 1910, one of the problems immediately attacked by the new organization was the development of standard, for the design and testing of electrical equipment that could be used without fear of initiating fires and explosions in underground coal mules. Research and investigation by Bureau personnel, supplemented by the published results of similar work by European mining authorities, led to the establishment of standards or "schedules." which guide manufacturers in the design of many types of electrically operated machines and devices used in. underground coal Mining. By issuing these standards, Bureau personnel establish the requirements to be met by such equipment before it tan be approved by the Bureau of Mines as permissible for use in gassy coal mines. Every 2 years the Bureau of Mines publishes a list of equipment that leas been accepted as approved or permissible during the preceding 2 calendar years. This is done to inform the mining industry of the availability of the latest equipment for safe use underground.]

Jan 1, 1964

By F. R. Lee

When the Bureau of Mines was established in July 1910, one of the problems immediately attacked by the new organization was the development of standard, for the design and testing of electrical equipment that could be used without fear of initiating fires and explosions in underground coal mines. Research and investigation by Bureau personnel, supplemented by the published results of similar work by European mining authorities, led to the establishment of standards or "schedules." which guide manufacturers ill the design of many types of electrically operated machines and devices used in underground coal Mining. By issuing these standards, Bureau personnel establish the requirements to be met by such equipment before it tan be approved by the Bureau of Mines as permissible for use in gassy coal mines. Every 2 years the Bureau of Mines publishes a list of equipment that leas been accepted as approved or permissible during the preceding 2 calendar years. This is done to inform the mining industry of the availability y of the latest equip¬ment for safe use underground.

Jan 1, 1964

By C. A. Mehring

[This paper, which describes the milling practice at the San Guillermo concentrator of the Compania Industrial "M Potosi", S.A., located at Chihuahua, Chihuahua, Mexico, is one of a series of similar papers being prepared by the United States Bureau of Mines. The concentrator treats lead-zinc-silver ore at the rata of 2,300-2,400 tons of dry material daily and produces lead concentrate and zinc concentrate by selective flotation methods. The lead concentrate is smelted at the Chihuahua plant of the American Smelting & Refining Co., and the zinc concentrate is shipped to various European smelters.]

Jan 1, 1933

This is the second of a series of reports on properties of commercial motor fuels made pursuant to a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the Department of the Interior. The first report gave data oil motor gasolines sold during the minter of 1935-36.3/ These gasoline surveys report results of inspections, in oil-company laboratories, of samples of gasoline obtained by representatives of oil companies from service-station pumps in marketing areas throughout the country. In the present survey are presented inspection data on 239 samples of regular- price gasoline, 166 samples of premium-price gasoline, and 157 samples of third-grade gasoline, a total of 562 samples collected during the summer of 1936.

Jan 1, 1937

By V. A. Cammarota

In this report, the effects of anode-production variables, such as aggregate coke sizes, pitch binder content, and baking cycle, were investigated. A small alumina reduction cell proved effective in evaluating anodes prepared from commercial materials and from lignite coke and pitch. Compressive strength was found to be the physical property most significantly influenced, but it did not appear to affect anode consumption. Specific carbon consumption, that is, the ratio of carbon in the anodic gas to carbon theoretically oxidized at the anode, was used as an index of anode consumption. It was found that an anode made with lignite coke and commercial pitch was very low in consumption; however, anodes made completely from lignite but by a different fabrication method showed high consumption and anode deterioration. Microscopic examination of anodes after electrolysis showed evidence of higher consumption at low current densities, and was useful in judging overall anode quality. Based on the physical properties of the anodes and their consumption during electrolysis, lignite can be a suitable material for anodes, provided the proper fabrication conditions are used.

Jan 1, 1970

By E. G. Baglin

As part of an effort to decrease U.S. dependence on imports of critical and strategic metals, the Bureau of Mines investigated three leaching methods for extracting the base metals and recovering platinum-group metals (PGM) from matte prepared from Stillwater Complex flotation concentrates. Because of a limited supply of natural material, synthetic matte of composition similar to matte prepared from natural concentrates was used to devise the extraction sequences. The validity of the sequences was verified with matte prepared from Stillwater concentrates. In two-stage matte leaching, first-stage H2S04 leaching extracted 99 pct of the nickel and iron from the matte but negligible amounts of copper and PGM. Second-stage oxidative leaching with Fe2(S04)3 or FeC13 solubilized more than 98 pct of the copper and no precious metals. Sequential leaching, in which acid and oxidizing lixiviants were added sequentially to the matte without an intervening filtration step, extracted 99 pct of the Fe, Ni, and Cu. A roasting-leaching technique, in which the residue from first-stage leaching was roasted between 360° and 500° C before a second leaching with H2S04, solubilized 98 pct of the copper. The three leaching methods yielded high-grade PGM residues containing more than 98 pct of the PGM in the matte.

Jan 1, 1982

As part of the overall development of a borehole mining system -develop backfilling techniques to reduce possible damage to the environment caused by either the cavities or the piles of sand tailings that result from in-borehole hydraulic mining. (Borehole mining is described in technology News No. 56.) Approach Water filled cavities at the bottom of boreholes are rapidly and economically backfilled by jetting a sand-tailings slurry underwater. How It Works The Bureau of Mines borehole mining system creates a cavity having a horizontal diameter of more than 50 feet. (See photograph). This cavity can be backfilled with much of the sand previously mined. The sand tailings or similar backfill material is dumped by a front end loader into a slurry mixing tank at the rate of about one ton every three minutes. Enough water is added to give a thick, but pumpable slurry. The slurry is pumped down the borehole through a string of 4-inch pipe to the cavity. After passing through a right elbow at the end of the pipe, the slurry is ejected through a nozzle. The resulting slurry jet emplaces the backfill at the outer wall of the cavity. To obtain an even distribution of fill in the cavity, the nozzle is slowly rotated. The nozzle and pipe assembly is supported from a turntable on the surface. See diagram.

Jan 1, 1981

By Linneas Laage, Thomas Weber, William Pomroy

"Underground mine fires can significantly influence mine ventilation airstreams, in some cases throttling or even reversing airflows. As a result, the performance of a metal and nonmetal mine stench fire warning system, which depends on the ventilation to carry the vital warning signal, under fire conditions is different from performance under nonfire conditions. The safety of underground miners can be jeopardized if the warning signal is delayed. This Bureau of Mines report describes research to investigate fire and stench warning system interactions. A computer model is presented that permits quantitative analysis of stench warning signal delays as a function of fire location and intensity. The results of a case study involving computer simulations of stench distribution in a hypothetical mine network subject to various fire exposures are also discussed. This case study illustrates a technique for identifying the areas within a mine that are subject to unacceptable warning signal delays, thereby enabling preemptive action by mine personnel, such as redeployment of stench injectors. INTRODUCTIONFires are an ever-present threat to the safety of underground miners. Since the smoke and toxic gas produced by a mine fire can be spread rapidly by the mine's ventilation system, mine evacuation must be accomplished as quickly as possible in the event of fire. In metal and nonmetal mines, the most common means of passing the fire warning signal to each miner is the stench system. The typical stench system utilizes ethyl mercaptan, a highly odoriferous organic compound, injected on the surface into the compressed and/or ventilation airstreams. Upon smelling the stench, workers evacuate the mine according to an emergency preplan.Although the stench system has been used successfully for over 60 yr, it has several serious shortcomings, owing to certain chemical properties of ethyl mercaptan and to certain performance characteristics and limitations of present injection systems.Recent Bureau research succeeded in upgrading the overall safety and effectiveness of the stench system through the use of a superior stench odorant and the development of improved stench injection equipment (1).4 This research has also investigated a specialized computer simulation model capable of calculating the precise concentration of stench in any mine ventilation network branch at any time after stench release (2). An adaptation of the computer model now enables the analysis of stench system and ventilation system interactions under the influence of a mine fire."

Jan 1, 1987