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By Powell. Alfred R.

"An investigation has been made of the applicability to a variety of coals, other than those from Illinois, of the Powell and Parr method of analysis for the forms of sulphur in coal.A complete study was made of the sulphur in the following coals:- Upper Freeport, Pa.; Pittsburgh seam, Pa.; Pocahontas No. 3, W, Va..; Letcher Co., Ky.; Morgan Co., Tenn.; and Cherokee Co., Kan.The method of analysis gave excellent results when applied to these coals. In the determination of pyrite, the iron-sulphur ratio checked in every case with the theoretical. After the extraction of the pyrite and sulphates, the remaining sulphur was proved to be organic in nature.This work indicated that sulphur exists in coal in three typical forms: - pyrite or marcasite, sulphates, and organic sulphur. A study of the changes which these forms undergo during coking has been made on a variety of coals, and the following five classes of reactions established.First. Complete decomposition of the pyrite and marcasite to ferrous sulphide, pyrrhotite, and hydrogen sulphide. This reaction begins at 300°C., is complete at 600 °C., and generally reaches its maximum between 400 and 500°C."

Mar 1, 1920

By Ted C. Briggs

A removable-jacket distortion apparatus was constructed and used to measure distortion coefficients for two high-pressure vessels. The measured distortion coefficients were used to compute distortion coefficients for volumes VI and (V1+V2) of a 1,000-atmosphere Burnett compressibility apparatus for the temperature range 0° to 75° C. Young?s modulus for Armco 17-4 PH stainless steel, heat treated to condition H1150-M, was computed from experimentally determined distortion coefficients. A 10-to 14-percent correction to the values obtained for Young's modulus may be required because pressure vessel end effects were neglected. The distortion coefficients of the compressibility apparatus are believed to be accurate to about 1 percent.

Jan 1, 1970

By N. A. Gokcen

Equilibrium partial pressures of gaseous HCl and H2O over aqueous binary and ternary solutions of HCl and AICls were calculated or estimated in the range of 20° to 110° C, and up to saturation with AlC13?6H2O. The results were extended to solutions containing less than 10 wt-pct FeCl3 by assuming that FeCl3 and AIC13 are equivalent on the molar basis, since both salts have trivalent cations with a cammon anion. The ionic activity coefficient of HCl and the equilibrium constant for dissolution of gaseous HCl were also computed. This research is part of the effort by the Bureau of Mines, U.S. Department of the Interior, to provide thermodynamic data to expand the technology base relevant to the extraction of alumina from nonbauxitic domestic raw materials.

Jan 1, 1980

By C. C. Shale

A semicommercia1, high-temperature electrostatic precipitator and adjunct equipment are described, and operating characteristics at 1,470° F and 80 psig are presented for both positive and negative polarity. Removal efficiency for negative corona waS about 91 to 96 percent while that for positive corona was only about 75 to 77 percent. Results are compared with those from bench-scale investigations, and equipment limitations are discussed. Theoretical aspects of the precipitation process are related to the operating characteristics.

Jan 1, 1969

Use instantaneous sampling to pinpoint dust sources and to Improve dust control on longwalls. Approach Use a dust monitor developed under a Bureau contract. How It Works Sampling can be done by either a moving or a stationary method. In the "moving' method, the dust monitor is carried by a survey engineer walking at the midpoint of the shearer Dust levels and face position (support number) are taken during all phases of the mining cycle while the shearer is cutting. These measurements can show how changes in airflow along the face, face specific; (rock partings) and cutting sequence (cutting the wedge) variables affect dust levels. In the "stationary sampling" method, the survey engineer stands with the RAM at a fixed location on the face. As the shearer approaches, the dust level and the distance to the shearer are recorded at 10-second intervals. Typically measurements start when the shearer is 20 feet from the sampling position and continue as the shearer passes the position until it is 20 feet away on the other side. Dust profiles around the machine are obtained at several fixed locations along the face only while the shearer is cutting.

Jan 1, 1982

By E. D. Gardner

"It has only been in recent years that the proper ventilation of metal mires has received serious consideration. Increasing temperature and humidity with greater depth in some of the larger mines of the West prevented the efficient operation of the mines and made the installation of mechanical ventilation systems necessary. Doors that interfere with tramming are generally needed to control properly the mechanically induced air currents and are one of the inherent disadvantages of the system. In fact the necessity for the use of doors in the main haulageways has discouraged the installation of mechanical ventilation in some metal mines.A number of mining companies in Arizona are using ventilation doors which can be opened and shut mechanically by the motorman without leaving his seat or stopping his train, end thus interfere very little with the transportation of the ore. The Copper Queen Branch of the Phelps-Dodge Corporation at Bisbee introduced these ventilation doors and adapted them from those in use in the company's coal mine at Dawson, New Mexico. Other mining companies have installed the same type of door and it is now being used in a number of districts in Arizona.The doors at the Calumet and Arizona mine in the Bisbee district are representative of those in use. The doors at this mine are substantially built of 2-inch lumber, are air tight, are well placed and have two openings or passageways. The main door, which is used for the motor trains, is 5 feet wide by 6 feet high and is opened by compressed air and closed by a counterweight. At the side of the motor door is the man door, which is 16 inches wide by 5 feet high and is opened and closed by hand."

Aug 1, 1921

By John H. Scott

At the request of the Mine Safety and Health Administration, U.S. Department of Labor, the Bureau of Mines evaluated the model BT 300 C-D blasting machine tester, manufactured and distributed by Research Energy of Ohio, Inc. (REO), to determine whether the tester performed as stated by the manufacturer and responded satisfactorily to electrical faults introduced into the blasting machine circuit. Tester readings were recorded for 13 blasting machines and for 12 circuits constructed to simulate the electrical parameters of actual machines. The tester readings were acceptable for all of the blasting machines, although the switch position assigned to one machine produced an off-scale reading. The tester responded satisfactorily to the simulated circuits and detected serious voltage or capacitance faults when they were introduced. However, it did not respond accurately to certain resistance faults. Temperature tests were also made, and the tester performed equally well at temperatures of 20°, 42°, and 81° F. This tester was judged a useful accessory for field checking blasting machines for defective batteries and capacitors, despite its limitations. It is recommended that the tester manufacturer specify the lowest acceptable reading at which a blasting machine may be used and below which the blasting machine should be returned to the laboratory or manufacturer for maintenance.

Jan 1, 1981

By Kathleen Madland Kowalski

In recent years the issue of human stress response in emergency workers has begun to receive attention. This paper presents a rationale for considering human stress as a significant factor in the management of emergencies It discusses the concept of stress, Critical Incident Stress in emergency responders, and intro¬duces the Critical Incident Stress Debriefing (CISD) process. It is suggested that in a disaster, the CISD process can improve the effectiveness of response teams on site, their turnaround time on site, and post disaster time off the job. This paper, prepared by a US Bureau of Mines research psychologist, offers some ideas to the mining industry in general, mine rescue trainers and more universally, to those responsible for developing emergency management plans.

Aug 1, 1998

Reduce dust at the auger mine face by modifying airflow patterns, around the minim machine. Approach Limited clearance between an auger miner and the mine root restricts airflow across the face and causes dust rollback. Directional sprays arc used to direct air across the face, thereby reducing dust rollback and increasing dust dilution (fig. 1). Laboratory and underground studies were used to test and optimize effectiveness of the directional sprays. Results of Laboratory Study Laboratory experiments were conducted in a simulated auger gallery equipped with a full-scale mock auger miner and bridge conveyor. A dual curtain configuration was used to direct the, ventilation, which averaged 2,700 cfm throughout the experiment. Testing variables included spray location, pressure, spacing, orientation, and number. Figure 2 shows the optimized directional spray system, also called the auger clearer spray system. The system consists of three sprays mounted alone the intake side of the miner. Sprays arc spaced 16 to 24 inches apart, and angled 30° toward the return side of the miner. The 24-inch spacing moved about 7% more air across the face than the 16-inch spacing; however, it resulted in some additional misting on the return side of the miner. A 30° orientation was more effective than a 60° orientation for moving air across the face and minimizing misting on the return side of the miner. Flat fan sprays arc used because their spray paths arc not obstructed by the top of the miner and mine roof, A 50° fan angle is used to minimize misting on the intake side of the miner.

Jan 1, 1989

By R. E. Peterson

The Bureau of Mines has undertaken beneficiation investigations on samples representing large tonnages of oxidized taconites in order to develop and evaluate applicable technologies for producing iron oxide concentrates from these materials. Information derived from the investigations can be used to expand the domestic iron raw-materials base and to establish the impact these taconite deposits may have on future national iron ore requirements. This report describes a process that includes reduction roasting, magnetic separation, and flotation, applied to a western Mesabi Range sample taken near Coleraine, Minn. The sample contained 36.8 pct iron and 46.0 pct silica, and represented 0.5 to 1 billion tons of crude material. An average of 962 lb/hr of oxidized taconite was roasted with 33 lb/hr of lignite in a 35-foot-long rotary kiln. Pulverized lignite and natural gas maintained the kiln operating temperature at 850° C. The roasted taconite was beneficiated by magnetic separation and cationic flotation in a 900-lb/hr pilot plant and yielded a product analyzing 68.1 pct iron and 4.6 pct silica, and containing 82.4 pct of the iron in the kiln feed.

Jan 1, 1981

By M. E. Tyrrell

The purpose of the work leading to this report was two-fold: (1) To determine the properties of cemented tungsten carbide modified by the addition of one, two, and five percent of titanium diboride, and (2) to compare the properties of these mixtures when sintered, hot-pressed, and flash-welded (resistance-sintered). Minor additions of titanium diboride to mixtures of 94 percent WC and 6 percent Co decrease mechanical strength but increase oxidation resistance in proportion to the amount of the addition. One percent of titanium diboride increased the hardness by 2 Rockwell A units. Hot-pressing produced compacts with the highest density and the best mechanical strength, but losses of cobalt were high and grain growth was pronounced.

Jan 1, 1962

Provide a means of evaluating the in place structural properties of coal seams and coal measure rocks in advance of mining. Approach Develop a sonic logging probe for use in dry wells, a condition common to shallow wells and semi-arid coal regions. How It Works The Bureaus' sonic probe differs from conventional sonic probes because it does not require fluid in the well to couple sonic vibrations to the drill hole wall. A self-contained hydraulic system forces pistons containing the measurement transducers against the wall and clamps them in position until the sonic waveform information has been recorded. The pistons are then retracted and the probe is raised or lowered in the well as required. In the clamped position, the piezoceramic transmitter emits a sonic pulse which travels along the drill hole wall and is detected at the receivers in the form of compressional (P) and shear (S) wave motion. The receivers are designed to be sensitive to either the (P) wave or (S) wave motion as determined by the operator so that discrimination between the two wave types is improved by comparison of the respective output channels, and the travel time between transmitter and detectors can be accurately determined. Use of two receiver stations eliminates errors in timing of pulse travel because of electronic delays inherent in the probe.

Jan 1, 1981

Determine the extent to which remote-sensing techniques, primarily lineament analysis, can be used to identify geologic structures that may affect the location and migration of subsidence over abandoned underground coal mines in the Colorado Springs, CO, area. Compile data using a geographic information system (GIS) to allow efficient and reproducible comparisons and analyses. Background The basis for evaluating abandoned mine land (AML) sites with remote-sensing techniques comes from past and ongoing Bureau ground control research using remote-sensing data to identify potential hazards caused by geologic structures (faults, joints, etc.) above active underground coal mines. Research showed that lineament (linear feature) analysis of Landsat Multispectral Scanner (MSS) images could indicate locations of fractures and fracture trends that had varying, but significant, impacts on the stability of mine openings. Such geologic structures should be identifiable over abandoned mines as well. If fractures are present, even if they arc not faults, they should represent areas of potential instability over these mines and, therefore, should tend to localize subsidence when it occurs, particularly for deep and moderately deep portions of mines.

Jan 1, 1992

By H. C. Miller

[California's sensational rise to supremacy as an oil-producing State in 1923 was accompanied by a loss of 62 lives. These 62 deaths were from oil-producing accidents alone and do not include fatalities at the refineries, on tankers, or on any work not directly connected with the drilling for and the production of oil. The number of facilities for 1923 was 82 per cent greater than in 1922, the next most fatal year, with a record of 34 lives lost. The data submitted in Table 1 show that for the calendar years 1917 to 1923 inclusive, an average of 4.74 million barrels of oil were produced per Vitality in the California oil fields. On this basis, the record for 1923, hough a trifle below the average, shove up slightly better than that for 1922.]

Jan 1, 1924

By E. C. Lane

The motor gasoline that is being marketed in the United States this winter (1928-29) is slightly more volatile than that gold a year ago. This characteristic is shown by a slight lowering of the distillation temperatures, particularly at the average initial and 20 per cent boiling points. Daring the past mine and a half years the Bureau of Mines has made semi annual surreys of the gasoline marketed in the United States; the Survey just completed is the nineteenth in the series. The 12 cities in which samples have been collected were chosen as representative of the more important marketing territories, as it was obviously impracticable to obtain a sample of every gasoline sold in the entire country.

Jan 1, 1929

By R. L. Montgomery

The literature has been surveyed and values recalculated for the heats and free energies of formation of solid rare-earth compounds at 298° K. In most instances it was necessary to estimate the entropies. Thermodynamic properties of aqueous rare-earth ions have also been calculated. INTRODUCTION The accumulation of thermochemical data on rare-earth compounds in recent years makes it possible to review the subject and to obtain more consistent and more reliable information than was available previously.

Jan 1, 1959

Provide the mining industry with a method for determining the gas content of ore bodies and associated strata for use in mine planning, Approach Samples of various rock types are collected and tested to determine gas content in conjunction with sample size, the collection method (i.e. whether the sample was collected from a core sample or by hand) mine gas emission, and the geologic location from which the sample was taken, such as near a fault, outburst area, or other geologic anomaly. How It Works Two methods were developed by the Bureau of Mines to determine the gas contents of rock samples. The first method developed involved dissolving minerals to measure gas emission. This method, however, can only be used with soluble minerals. A second method, therefore, was developed for use with insoluble minerals. With this method, the sample is crushed in a ball mill. Although the dissolution method is faster and more accurate to use, the crushing method is also advantageous because its use can more closely approximate a mining situation; the sample is crushed as in mining and the amount of gas released relates to the amount of gas that would be released during a mining operation. The dissolution method is applied to soluble minerals, such as rock, salt, or trona, in a sealed chamber. Gases released during dissolution are collected for analysis by gas chromatography. One advantage in using the dissolution method is that the test apparatus is relatively inexpensive. In addition, test can be performed at any scale, from single crystal samples to a solution mining operation.

Jan 1, 1983

By Alton B. Cook

Data are presented to show oil vaporization resulting from the passage of natural gas through a sand-packed tube saturated with synthetic reservoir oils. The Bureau of Mines performed 13 experiments, using reservoir oils synthesized with base crude oils of approximately 22°, 35°, and 45° API, at 100°, 175°, or 250° F and 1,100, 2,600, or 4,100 psia. It has been determined that the amount of vaporization is significant if proper conditions exist. These experiments show that oil vaporization depends on pressure, temperature, volatility of the oil, and amount of gas cycled. Increases in each of these conditions increase the volume of oil vaporized.

Jan 1, 1969

By Daniel Edelstein

Demand for arsenic trioxide increased markedly during 1984 as a result of increased use of arsenical wood preservatives and increased use of arsenicals in agriculture. The increase in agricultural demand was due to a return to production of land with-held from cotton planting under an agriculture program for acreage diversion for some 1983 crops. Supplies of arsenic trioxide were more than adequate to meet increased demand, and prices either declined from, or remained at, the low 1983 levels. In June, ASARCO Incorporated announced plans to close its Tacoma, WA, smelter by mid-1985. Domestic Data Coverage.-Refined arsenic trioxide was produced by two U.S. companies. The major producer voluntarily reported its production to the Bureau of Mines, but to prevent disclosure of proprietary data, the production data have been withheld.

Jan 1, 1985

By Janet Torma-Krajewski, Pauline Lewis, Paul Gust, Lisa Steiner, Kean Johnson

Since 1990 and the publication of the Ergonomics Program Management Guidelines for Meatpacking Plants by the US Occupational Safety and Health Administration, numerous reports of companies implementing ergonomics program have been published. However, despite these numerous reports, no examples of implementing an ergonomics program in the mining industry have been reported. In 2000, NIOSH initiated a long-term project to demonstrate the implementation of an ergonomics process designed to identify and reduce exposures to ergonomic risk factors found in mining. The mine selected for this project was the Jim Bridger Mine, a surface coal mine located 35 miles northeast of Rock Springs, Sweetwater County, WY. This paper discusses how a large, surface coal mine implemented an ergonomics program and the lessons learned while doing so.