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By Howard E. Parkinson

Since 1969, the Department of Interior, Bureau of Mines, has carried out communications research. Research has been directed toward developing emergency and nonemergency mine communications. This paper gives an overview of the progress made in the last two years. Particular emphasis is given to the overall program, noise and signal measurements, systems studies, guidelines, products, and demonstrations now being carried on in operating mines.

By D. R. Douslin

This report describes an inclined-piston pressure gage that operates from a zero-pressure datum level. The gage is adaptable to accurate vapor-pressure measurements in the low and intermediate pressure range, 0.01 to 40 mm (mercury). Residual friction in the oil-lubricated piston-cylinder combination is eliminated by a unique oscillatory method that is free of end thrust on the piston and allows the full sensitivity of the gage to be realized. The axial component of the weight-to-area ratio of the piston is determined by measuring the angle of inclination with a goniometer that can be read to 1 sec. Accuracy of the gage proper is estimated to range from 0.001 to 0.012 mm from lower to upper pressure limits. Its highest practical sensitivity is about 0.0005 mm. As a test, the vapor pressures of ice and water were measured in the range -30° to +20° C.

Jan 1, 1963

By L. C. Marchant

Results of detailed analyses of four cores from the Threemile Canyon area in the P. R. Spring tar sand deposit in Utah are reported by the Bureau of Mines. The cores were obtained by the Utah Geological and Mineralogical Sur-vey as part of a l7-corehole evaluation program in the P. R. Spring, Hill Creek, and Rim Rock tar sand deposits. Average properties of the oil zone in the Threemile Canyon area as deter-mined from these cores are as follows: Oil saturation, 67.4 pet of pore volume; porosity, 29.2 pct; permeability before oil extraction, 133 millidarcies; and permeability after oil extraction, 2,855 millidarcies. Average net thickness of the oil zone is 23.8 ft and average depth to the top of the oil zone is 189 ft.

Jan 1, 1974

By E. O. Binyon

The Blue Metal corundum-andalusite deposit, in the Buckskin Mining district, Douglas County, Nev., was explored by the Bureau of Mines in 1945. The results of that work were presented in Report of Investigations 3895, exploration of the Blue Metal Corundum Property, Douglas County, Nev. published in August 1946. That report also describes the property in detail, giving location, ownership, history, geology, and data on beneficiation tests. Further exploration was carried on in April and Way 1947, the results of which are presented in this report. The work consisted of 175 feet of drift and crosscut, bringing the total to 398 feet of underground working, as shown in figures 1 and 2. The 23-foot drift, which was the last work of the initial project, was extended 99 feet northward along the shear zone, and three crosscuts, spaced at approximately equal intervals along the drift, were driven to country rock on the hanging and foot walls of the zone.

Jan 1, 1948

Reduce longwall intake contamination by controlling respirable dust generated by the stage loader. Approach Install a water-powered scrubber on the stage loader immediately outby the crusher. Dusty air from the crusher is drawn through the scrubber and a clean air discharge is delivered into the primary face airflow. How It Works The contamination of intake air is a significant dust control problem often overlooked on many longwall faces. This dust source contributes to the full shift dust exposure of all face personnel, and thus can significantly affect compliance with Federal regulations. Several sources contribute to contamination; however, dust generated by the stage loader crusher is the single largest source. The breaking action of the crusher generates a tremendous quantity of dust, which mixes with the primary ventilation airstream and is carried down the entire length of the longwall face. The installation of a water-powered scrubber (see diagram) has proven effective in controlling crusher-generated dust. The scrubber is mounted immediately outby the crusher. A duct is placed over the scrubber intake and attached to a flanged opening over the crusher discharge. In

Jan 1, 1982

By Bob Thomas, Syd Peng, Quanzhong Gu, Gene Wilson, Gerald L. Finfinger

Identifying the properties of overlying rocks in underground mining operations is important to ensure the appropriate roof support design is used to maintain stability of the mine entries. Recently J. H. Fletcher & Co. developed a monitoring and control system for roof bolters for the underground mining industry. The system records the drilling parameters used during roof bolt drilling and the information can provide insight into the physical properties of the roof strata. The parameters include thrust, rotational speed, torque and velocity and the measurements are collected every 0.1 second during the operation. The drilling parameters were analyzed to determine the application of identifying the strength of rocks being drilled from the measurements. The data was converted into the specific energy of drilling which is a measure of the amount of energy required for removing a given unit of rock during a drilling operation. The laboratory studies completed to date indicate a fairly high correlation between the specific energy of drilling and the unconfined compressive strength of :he rocks that were drilled. Additionally, the drilling parameters were shown to be effective for identifying the presence of fractures or bed separations between rock layers. The thrust, torque and specific energy of drilling were all good indicators for identifying the fractures or separations. Regardless of the drilling parameters used during the drilling experiments, the location of the fractures were identified. In order to determine the application of the drilling parameters for identifying roof rock properties, two series of experiments were conducted. The first series of experiments used three "manufactured" roof layers that had various rock samples embedded in concrete blocks. The rock samples included three types of sandstone, marble, and argillite. Another concrete block was poured with foam inserts to simulate large bedding separations (2 to 8-in). Two other manufactured blocks were constructed using high-strength concrete with cardboard layers embedded to simulate smaller fractures or bedding separations. The size of the cardboard layers varied from 1/8- to 1-in thick. One of the blocks had the cardboard layers embedded at an inclined angle to determine the effect of the orientation on the drilling parameters. A series of experiments was conducted with the rotational speed and the penetration rate held constant and the thrust and torque allowed to vary. The information collected from the experiments is used to determine the application of the drilling parameter measurements for identifying rock properties, fractures and bedding separations.

Reduce the noise radiated by the auger miner cutting head (typically 105 dBA at the face) by 10 dBA without compromising the durability or productivity of the tool. Approach Research was conducted by the Bureau of Mines to identify the noise sources of auger miners with emphasis on the cutting head and coal cutting process. The overall noise level generated by the coal cutting process was found to depend greatly upon the structural characteristics of the auger cutting head. Based on this information, a quieter cutting head was

Jan 1, 1982

By Fred C. Turin, Kim M. Cornelius

Work in underground coal mines is repetitive and physically demanding. Workers commonly report a wide range of aches and pains. Management at one mine was concerned about increased reporting of aches and pains by roof bolting machine operators. An analysis of roof bolting tasks was conducted at this mine to identify early warning signs of cumulative trauma. Health and safety risk factors were identified and recommendations to reduce cumulative trauma exposure were provided. Recommendations addressed job procedures, equipment design, and worker awareness of risk factors.

By H. M. Lawrence

The recovery of phosphate rack from the ores in the land-pebble district of Florida is a simple washing and screening operation. In the gashing plants coarse phosphate only is saved. Log-Washer overflows and screen-undersize products containing an appreciable content of fine phosphate are discarded. The phosphate grains in the material discharged to waste are generally finer in size than the mesh--14 to 20 mesh or 0.346 to 0.03 inch--of the finest screen in the washer. The operators state that the washers ordinarily recover from 50 to 60 per cent of the phosphate content of the matrix mined. Any increase that can be effected in the recovery of phosphate would be of advantage to the industry and would conserve the mineral resources of the country. In considering possible methods that might increase the recovery obtained in phosphate-washing plants the application of flotation, if it could be successfully developed, seemed to warrant investigation.

Jan 1, 1928

By D. E. Wolfson

The Bureau of Mines investigated the use of preheated coal in carbonization operations. Liquor yields and coking times were reduced, coke quality was improved, and smokeless pipeline charging to coke ovens should eliminate a serious source of pollution.

Jan 1, 1972

Rapidly identify unstable mine waste embankments and similar dam structures. Approach Aerial photography, geotechnical instrumentation, and telephone or satellite data transmission are used to supplement walk-around inspect ions. How It Works Embankment stability and other indicators of structural integrity are evaluated using aerial photography, and on-site unattended instruments and data transmitting systems. Evidence of external movement and water seepage is obtained from aerial photography and photogrammetric evaluation techniques. Surface points marked by stake- mounted targets are monitored photographically at time intervals of several weeks or months. Photographic measurements of x, y, and z coordinates of these points are obtained from flying a series of photo-runs over the dam.

Jan 1, 1979

By R. V. Ramani, A. S. C. Owili-eger

The quantity of methane emitted into the mine atmosphere and the movement of gas through solid coal and the adjoining country rock are dependent on the physical properties of the medium, boundary con¬ditions, the initial gas pressure distribution, and the combination of natural and mining factors. Functional relationships between these factors are not yet known. Consequently, the development of rigorous mathematical models to predict methane flow into the mine air is difficult and to date no model has been reported which is capable of such a function. Thus far, empirical formulas available for the calculation of gas quantity released from underground sources require too much his¬torical data, not currently available. Again, these estimations are at best only crudely approximate. The numerical methods available have not been made practical enough for industry wide application. Therefore, the development of a relationship amenable to numerical analysis and practical enough for use in the industry would provide the flexibility lacking in analytical approaches. The mathematical models given in equations (7) and (8) are further attempts in presenting practical models for predicting the quantity of methane emission into the mine environment. Equation (7) is the steady state model and equation (8) is the unsteady state model.

Jan 1, 1974

By Robert P. Vinson, Fred N. Kissell, Edward D. Thimons

The Bureau of Mines investigated the presence and extent of methane accumulations in mine roof cavities using a full-scale mine model. Methane was released at a constant rate into the roof of a cavity built onto a 700-ft wind tunnel. Two box-shaped roof cavities were used in the study: one had a volume of 114.7 cu ft; and the other had a volume of 57.3 cu ft. Methane concentration was measured at 28 sampling points in the cavities using 21 different combinations of gas emission rates and air velocities. Brattice hung in the cavity helped reduce methane concentrations without auxiliary ventilation. It was also found that the effective ventilation rate increased by a factor of 40 in the large cavity and by a factor of 20 in the small cavity when air velocity was increased from 100 to 600 fpm.

Jan 1, 1978

By Frank J.

The increased demand for aluminum for military purposes during World War II necessitated the development of domestic deposits of alumina-bearing ores. Kaolin, siliceous bauxites, anorthosite, and diaspore-containing clays have been investigated and studied in the laboratory and pilot plant. The Bureau of Mines is preparing a series of reports covering investigations of these ores. The tests contained in this report are restricted to sintering and leaching tests on kaolin from South Carolina, where extensive deposits were proved to exist. The leach liquors were found to have substantially the same composition as those produced from the diaspore-containing clays, and therefore it would be expected that no difficulty would be experienced in producing calcined alumina of relatively coarse particle size and with other properties conforming to the specifications for metallurgical-grade alumina.

May 1, 1947

Continuously monitor air-borne radon daughters that are a hazard to underground miners. Approach A beta detector continuously counts beta activity collected on a filter paper to allow calculation of exposure in working level units. How It Works At each Site a constant flow pump draws mine air through a fiberglass filter located in front of a beta detector (pancake type Geiger Mueller tube), Radioactive particles (products of the radon 222 gas emanating from the mine walls) collect on the filter and decay, releasing alpha and beta particles as well as gamma rays. A portion of the beta particles penetrate the Geiger tube window and create electrical pulses in the tube. These pulses are then amplified and sent by a coaxial type or shielded electrical cable to a central monitor located some distance from a working level detector. At the central monitor incoming Signals are amplified and fed into two channels, (See the block

Jan 1, 1979

By Edward A. Mihok

Laboratory batch-flow tests conducted on a highly ferruginous acid mine water with an activated carbon showed that ferrous iron is rapidly oxidized. This indicates that air oxidation of ferruginous acid in mine waters is catalyzed by activated carbon. The ferrous iron content of an acid mine water flowing through an aspirated activated carbon column was reduced from about 700 to about 10 parts per million in less than 1 minute. Highly efficient ferrous iron oxidation was achieved by conditioning the activated carbon by repeated treatment with acid mine water and air. The reaction proceeds rapidly in the acid environment (pH about 2.5) engendered by ferrous iron oxidation. The activated carbon was used repeatedly with little loss in efficiency, no discoloration, or solids deposition. In these batch tests, about one-third of the iron was adsorbed by the carbon, but with continuous flow, little iron adsorption is expected. Incorporating a catalytic oxidation step in the treatment of acid mine waters containing ferrous iron would greatly facilitate neutralization--precise control of pH, lower reagent costs, elimination of aeration equipment, and smaller holding ponds.

Jan 1, 1969

By R. V. Ramani, V. T. Burgos, J. A. McClay

Cost Systems Cost systems are organized methods of collecting, allocating, and accumulating resource utility expressed in terms of money. There are two major spheres of cost accumulation: financial accounting and cost accounting. Financial accounting deals primarily with historical costs and provides a means of measuring and recording cost events which have al¬ready taken place. While there are no legal requirements to control the methods of recording and reporting cost data in the United States, the procedures in use are guided by professional organizations such as the American Institute of Certified Public Accountants. The final pro¬ducts of financial accounting practices are the income statement and balance sheet which describe the financial status of the organization under study. Cost or managerial accounting is an expansion of financial ac¬counting procedures, providing more detailed cost breakdowns on present operations with one objective being the projection of present costs into the future. The projection process tends to limit the accuracy of the information; however, to management and project justification per¬sonnel, data on future operations tends to be of greater value. The basic principle behind cost accounting is the cost cycle. As products are developed from raw materials, the value of the work-in¬process increases due to the cost input of the various fabricating ele¬ments. Thus, from the basic input elements of facilities, labor, and raw materials, costs are added to each unit of production as a function of the work performed on that unit.

Jan 1, 1975

By D. Montagna

Large quantities of zinc-base die-cast scrap containing 3 to 4 percent aluminum are presently refined by mixing with other secondary zinc products such as galvanizer dross and distilling in a retort. The Bureau of Mines investigated alternate aluminum removal processes utilizing low-cost fluxes. Basing the investigation on the metallurgical principle that a reactive impurity can be removed from a less reactive matrix metal by melting under a flux consisting of a salt or oxide of a metal less reactive than the impurity, three separate flux mixtures were studied. In the first flux system, [FeCl3] + NaCI (the active component is underlined), part of the aluminum is' eliminated by the formation of volatile aluminum chloride and the rest by the creation of a high melting point iron-aluminum intermetallic compound that can be separated from the remaining molten zinc by filtration. Aluminum removal in the second system, [Fe203] + CaClz + NaCI, is effected by the formation of the iron-aluminum compound and possibly aluminum oxide. The third system, spent sal skimmings--essentially a mixture of [ZnCl2], NH4Cl, and ZnO, depends solely on aluminum chloride formation. Of the three flux systems investigated, the best results obtained were with system 3. Aluminum was reduced in the molten die-cast alloy from 4.10 percent to 0.01 percent when depleted sal skimmings were used.

Jan 1, 1969

By R. V. Ramani, V. T. Burgos, J. A. McClay

Cost Data Library The data retained in the Cost Data Library is of a semi¬permanent nature in that it is held in storage for immediate use with the program although its contents may require periodic evaluation to maintain it in a current status. The library is composed of six arrays containing both technical and cost data. The following description of the library input system provides the information necessary to maintain an active storage file. Array POWERA: FORMAT (8F10.0) - contains the step groupings of the power rate schedule for power cost computations. Four input data cards are required to fill this storage area. Card Column 1 1 - 10 Demand in Kilowatts for the First Step of the Demand Rate Schedule 11 - 20 Demand in Kilowatts for the Second Step of the Demand Rate Schedule y 41 - 50 Demand in Kilowatts for Fifth Step of the Demand Rate Schedule 51 - 60 Maximum Demand Level for this Rate Schedule 61 - 70 Percent Power Factor for this Rate Schedule 71 - 80 Unassigned 2 1 - 10 First Step Demand Charge, $/Kw 11 - 20 Second Step Demand Charge, $/Kw 4¬ 41 - 50 Fifth Step Demand Charge, $/Kw

Jan 1, 1975

By John W. Brown

Electrical resistivity surveys were conducted at three sites in Wyoming in an attempt to detect underground rubble zones in oil shale and to determine their size and resistivity contrast. The zones were detected at Rock Springs sites 4 and 5, but none were detected at Green River site 1. The resistivity of the rubble zones at sites 4 and 5 is greater than that of the surrounding rock. The zones at sites 4 and 5 are concluded to be roughly ovaloid in shape, with a horizontal diameter of 33 m and a vertical thickness of 24 m. Both rubble zones and the blasting that created them are considered to be centered at a depth of 24 m.

Jan 1, 1972