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By Jennifer S. Riefenberg

The U.S. Bureau of Mines conducts basic and applied research related to predicting, eliminating, and/or controlling rock bursts in underground hard-rock mines and coal bumps in underground coal mines. An important element in this research is the development of a reliable and efficient microseismic source location technique. This report presents the results of a Bureau study to develop and evaluate a new algorithm to locate microseismic events based on the Simplex method, a powerful linear programming technique. The technique was tested on both field data and simulated data. Microseismic event source locations obtained with this new Simplex-based algorithm were shown to have less error than those locations obtained using a least squares method. It was concluded that the Simplex approach to source location of microseismic events can be used effectively in microseismic monitoring.

Jan 1, 1989

By W. J. Boone, Will E. DeVaney, Lowell Stroud

This report is the fifth in a series presenting equilibrium vapor - liquid data for helium- bearing natural gases . It covers a 0.41 - mole - percent - helium natural gas that may be processed in the Department of the Interior's longrange helium conservation program . A Bureau of Mines phase equilibrium apparatus was used to obtain 139 samples of equilibrium vapor and liquid phases at 85 experimental conditions at temperatures from 0 ° to -299 ° F and at pressures from 100 to 500 psia . An appendix covers phase data at 100 , 200 , and 300 psia and at temperatures from -125 ° to -275 ° F for the dehydrated gas containing its original concentration ( 0.2 mole - percent ) of carbon dioxide , and the effect of a preliminary hydrocarbon trap upon subsequent vapor - liquid compositions .

Jan 1, 1964

By Christopher C. Jobes

This U.S. Bureau of Mines report describes a system to determine the position and heading of a mining machine during maneuvers in the face area of an operating mine section. The system is the first step in the development of a guidance system for automated mining machines. The position and heading algorithm is described, and a preliminary error analysis is performed. The sensors employed were linear position transducers mounted on a mining machine with their cables attached to points on a stationary reference. Four linear position transducers were used to provide a data redundancy that increased the reliability of the guidance system. The linear position information obtained from the transducers was processed mathematically via the position and heading algorithm to provide the desired position and heading information. The algorithm takes advantage of sensor redundancy to continually test the accuracy of the sensor data. The major sources of error were determined to be the linear position transducers, the analog-to-digital (A/D) converter used to interpret the data, and the sampling frequency of the measurement system. These sources of error were evaluated to determine their inaccuracies for use in calculating the overall system accuracy.

Jan 1, 1990

By E. G. Davis

The Bureau of Mines studied tailings samples from 11 large-scale western copper operations to determine the potential for recovery of rutile and other critical and strategic minerals. Up to 15 pounds per short ton (lb/st) Ti02 was found ion these samples; however, only 9 to 44 pct of the Ti02 was liberated rutile. For one sample, gravity preconcentra-tion, grinding, and flotation recovered 34 pct of the Ti02 in a 54.8-pct-Ti02 concentrate. Over 0.38 Ib/st W was found in some of the tailings sampleso Scheelite was identified as the major W mineral. Nine of the eleven samples contained about 0.02 to 0.18 Ib/st Co. Pyrite was the principal Co-bearing sulfide mineral, with Co contained in about one-fifth of the pyrite grains. Up to 30 pct of the Co was concentrated in a bulk sulfide flotation concentrate.

Jan 1, 1988

By Carlon S. Land

The Bureau of Mines investigated the influence of a free gas saturation on oil recovery by water drive. A digital computer was used to calculate the combined oil recovery from solution-gas drive to various states of depletion. Results of these calculations are compared and optimum conditions for the maximum oil recovery are found for various fluid-rock systems. For most of the fluid-rock systems, the calculations show an optimum gas saturation other than zero. Using fluid and rock properties as parameters, graphs are plotted showing the optimum gas saturation and increase in oil recovery brought about by the gas saturation. The effects of fluid properties and relative permeability on the optimum gas saturation are seen in these graphs. The graphs can be used as guides in connection with other considerations in determining the optimum time to start a waterflood. They should also be helpful in determining the MER of a water-drive reservoir. The effects of compressibility and solubility of the trapped gas saturation are investigated for select cases using a backward difference scheme to solve the partial differential equation of three-phase flow. From these calculations, it is observed that some benefit of a gas saturation remains for injection pressures up to 1.5 times the original bubble-point pressure.

Jan 1, 1974

By R. T. Johansen, R. J. Heemstra

In water flooding the gradual accumulation of insoluble materials on the sand face causes the injection pressures to increase while decreasing the amount of water injected . This plugging material often is composed primarily of insoluble precipitates of calcium , iron , and magnesium . Treatment with sodium tripolyphosphate ( STP ) either eliminates or reduces the formation of precipitates . Field tests are discussed showing the almost immediate effects of using STP in the injection water . Methods of treatment , solubility of STP in fresh water and brines , and precautions to observe when starting to treat a waterflood with this chemical are given . Laboratory data show that the preferential wettability of a crude oil for reservoir rock can be reversed by adding a small amount of STP to the flooding water . This reversal in wetting tendency should not only decrease the injection pressures but also increase oil recovery by improving the sweep efficiency of a water flood .

Jan 1, 1964

By G. R. Palmer

Using a fluidized, countercurrent multiple-compartment ion-exchange (MCIX) column previously developed by the Bureau of Mines, Bureau researchers have successfully extracted uranium from a simulated acidic in situ leach liquor that contained 150 ppm U30s? This successful demonstration of the MCIX system is reported, and the effects of varying the operating conditions on the performance of the system are also examined. Operating the MCIX system with a flow rate of 15 gpm/ft2 and an aqueous-to-resin flow ratio of 200:1, more than 90 percent of the uranium Has extracted, and a resin containing approximately 28 grams U308 per liter was produced. The absorption column used to investigate the operating variables was approximately 18 feet long with a 2-inch ID and was divided into compartments that were 1 foot long.

Jan 1, 1980

By Charles Vaught, Jeff Duncan, Michael J. Brnich, Lisa J. Steiner

This document contains most of the materials needed to use the exercise. The main part of the document is the instructor's copy. It tells how to use the exercise, presents the objectives, the master answer sheet, the scoring key, and discussion notes to be used following the exercise. The next section summarizes results from field tests of the exercise, and reports the miners' evaluation of the activity. The last part of this document is three appendices. Appendix A is the exercise problem booklet. This booklet can be duplicated locally. The booklets are reusable. One is needed for every person in the classroom. Appendix B is the answer sheet. Copies of this answer sheet must have the latent image (invisible) ink answers that appear in Appendix C printed on them.3 Answer sheets are consumable. One is needed for each person or each small group of persons who work the exercise. Exercise Summary Read this section first. It determines if the exercise is appropriate for your classes. If you choose to use the exercise, examine the table of contents and review the remainder of this document. Type: Latent image Audience: Remote control and extended cut miner operators and face crews Length: Eight questions (30 minutes for administration plus 30 for discussion) Skills: Remote control mining procedures including remote control mining, taking extended cuts, resetting breaker on mining machine, and setting timbers. Communicating mine conditions, influencing safe behaviors when mine conditions are less than stable Location: Underground coal mine, four section continuous mining operation Average seam height is 48 inches Problem: Your regular job is on the general labor crew at Cripple Creek #9 mine, a four section continuous mining operation. The mains are 9 entries wide and panels are 5 entries across. You and the rest of the crew had annual refresher training about 3 months ago. For the past few days you have been sent to 2 South panel to fill in as the third shuttle car operator. This morning, however, your buggy is down. The face boss asks you to get the scoop and take seven or eight timbers to the number 5 entry because the last shift got off sight line. The miner will be working in entry 5 while the bolter crew pins entry 4. When you get up to the face you see that Mo, the remote control continuous miner operator, has rounded off the left inby corner in order to make his first cuts in the right hand rib. Now, he has squared around enough so that you and Red, the miner helper, can set some posts on the corner. The two of you set posts along the left inby rib of #5 entry while the shuttle car operator waits. You are in a tight spot when Mo decides to start mining. You must decide where the best place is to stand for safety and to be out of the way.

Jan 10, 1999

By J. M. Davidson

The potassium mineral polyhalite (K2SO4.MgSO4.2CaSO4.2H2O) found in large deposits in western Texas and southeastern New Mexico is associated with varying amounts of halite (sodium, chloride, NaCl) and anhydrite (calcium sulphate, CaSO4). Although the anhydrite, because of its low solubility and slow rate of solution, is relatively inert, the halite is dissolved immediately in any process solution with which the polyhalite comes in contact. Limited quantities of sodium chloride in the liquors used for the hot extraction of polyhalite materially improve the results obtained, but only a very small sodium chloride content may be desired in the entering polyhalite in other procedures, such as Bureau of Mines process. In all of the processes suggested for the recovery-of potassium sulphate from polyhalite the control of the sodium chloride content will be desirable, if not absolutely essential to efficient operation.

Jan 1, 1934

By A. J. Kraemer

"During the past several years a great deal of discussion has centered around the question of the permissible limit of sulphur content in fuels for automotive and aviation motors. Under certain conditions of operation, sulphur in motor fuels causes the formation of corrosive substances which attack bearings, wrist pins, and other parts of engines. On the other hand, in making gasoline from certain stocks, the gasoline fraction normally contains a relatively large proportion of sulphur compounds. By the generally used processes of reducing the sulphur content, a significant part of the gasoline fraction is lost as motor fuel, and added expenses are entailed for chemicals, labor, and other process costs. This condition has been an economic burden to some refiners of high-sulphur crudes. In some instances the treating losses have been rather severe and the treating costs relatively high, but the data presented in this paper indicate that the reduction of sulphur content of motor fuel is a problem to a relatively small number of refiners and of little or no concern to the remainder; in fact, more than 90 per cent of the 153 samples analyzed passed the Federal specification requirement, Which limits the sulphur content to 0.10 per cent. 3This report is based upon the results of an examination for sulphur content, Doctor test, copper strip corrosion, and color of the samples collected during January, 1930, for the twenty-first semiannual gasoline survey of the Bureau of Mines. The results of the gravity ad distillation tests of the survey were published as Report of Investigations 2995. The numbering of the samples given in this report is the same as in Report of Investigations 2995; for example, No. 25 of this report is the same sample as No. 25 of Report of Investigations 2995."

Jun 1, 1930

By Lester M. Adams

In 1980, the Bureau of Mines surveyed a group of mine seals in Randolph County, WV, to evaluate their effectiveness for reducing toxic pollutants in mine water discharges. The survey focused on 11 block wet mine seals, but mine seals of several other types were also examined. The seals were installed in 1966 and 1967 in abandoned drift portals by the Federal Water Quality Administration (FWQA), a predecessor of the Environmental Protection Agency (EPA), in cooperation with the Bureau of Mines and other Federal and State agencies, in a project known as Elkins Mine Drainage Pollution Control Demonstration Project. The seals were designed to prevent air from entering the mine portals while allowing mine water to flow out. It was believed that by preventing air from entering inactive or abandoned mines, the formation of toxic pollutants and acid mine drainage (AMD) could be reduced. Evaluation of the seals was based on water flow measurements, water analyses, and visual observations. The Bureau's 1980 data were compared with past data collected by the EPA. Several leaks and failures were observed in the clay seals, as evidenced by apparent blowouts and the absence of vegetation where the mine water surfaced. Analyses of the 1980 data indicated some improvement in the quality of water discharged from many of the wet air seals.

Jan 1, 1984

By Oliver C. Fursman

This work was conducted to determine the feasibility of producing aluminum-silicon alloys in a pit-type, three-phase electric-arc furnace. Two carbon-lined furnaces were used in the tests. The power input ranged from 120 to 240 kw. in the small furnace and from 420 to 460 kw. in the large furnace. Energy consumption ranged from 5.3 to 11.5 kw.-hr. per pound of alloy produced and electrode consumption, from 240 to 510 pounds per ton of alloy produced. A wide range of crude aluminum-silicon alloys was produced by direct smelting of clays or similar aluminum silicate raw materials, using hogged fuel or wood chips as the major source of carbon in the furnace charge, and silicon of high grade was produced by smelting quartz. The aluminum content of the aluminum-silicon alloys ranged from 15 to 55 percent. Alloys produced from a white opaline-silicate clay were relatively free of iron, titanium, and other impurities. Those produced from western fire clays and kyanite, although richer in aluminum, contained considerable amounts of impurities. The purity of the alloys depended largely on the composition of the raw materials.

Jan 1, 1960

By A. C. Fieldner

In the course of its investigations on the properties of coal and in rendering fuel-inspection service to other agencies of the Government, the Bureau of Mines has accumulated a comprehensive file of coal analyses that includes data on virtually every coal field of commercial importance in the United States. As knowledge of the composition of coal is potentially valuable to every user of coal, the Bureau publishes its analytical records. Before 1921 such publications contained analyses of coal from all parts of the United States; individual analyses or average analyses of a series of shipments of coal were given with the name and location of the mine producing the coal. Beginning in 1921 the analyses were published by separate States because the quantity of data had become so great. The separate papers published to date, with Bureau of Mines Technical Paper numbers, are as follows: Alabama, 347; Arkansas, 416; Colorado, 574; Illinois, 634 and 641; Indiana, 417; Iowa, 269; Kansas, 455; Kentucky, 30S; Maryland, 465; Missouri, 366; Montana, 529; New Mexico, 569; Ohio, 344; Oklahoma, 411 ; Pennsylvania (bituminous), 590; Tennessee, 356; Utah, 345; Virginia, 365; Washington, 491 and 618 (618, published in 1941, supplements 491); West Virginia, 405 and 626; and Wyoming, 484. From time to time the various papers will be revised to include later analyses and other data. The Bureau of Mines annually receives many inquiries as to the composition of coals obtained from specific localities or, conversely, as to the localities from which a given kind of coal may be obtained. This paper presents a summary, in tabular form, of the composition of commercial coal resources of the country. Specimen analyses are given exemplifying the analysis of coal mined in each coal-producing county, or, where it was feasible, coal from each bed in each county; also, ranges of analyses, within which the composition of most of the coal represented will fall, are given where there were enough analyses to permit satisfactory determination of the ranges. In addition, the degree of metamorphism from lignite toward anthracite of much of the coal is indicated by the classification by rank. This classification reveals to more experienced users of coal some of the general properties of coal, that is, whether the flame will be long or short, whether the coal will cake in the fire, and how it is likely to behave on exposure and in storage.

Jan 1, 1942

By M. H. Stanczyk, I. L. Feld

Dewatering of typical Florida phosphate rock slime by electro - osmotic techniques was investigated to determine if a compacted , plastic solid product could be obtained with simultaneous recovery of the water for re - use . Tests with porous cathodes and rod - type anodes imbedded in dilute slime charges of up to 4 tons in weight showed that the slime could be dewatered to about 35 percent solids . The dewatered products had the consistency of modeling clay . In the large - scale tests using 2.5 - foot electrode spacings , about 21 kilowatthours of power were consumed per ton of water removed in thickening the slime from 17 to 25 percent solids , but the rate of water removal was so slow that the process was not considered commercially feasible . Other tests made with electrode spacings of from 2.5 to 8 feet showed that more rapid dewatering could be obtained but that the power required was excessive . However , for special uses such as stabilizing slime pond dikes where the cost of dewatering might not be a prime requisite , high voltages could be used to rapidly remove the water . Tests of 400 - pound slime charges using a combination of electroosmosis and vacuum filtration showed that the rate of dewatering could be expedited . The average power required to thicken a ton of slime from 15 to 35 percent solids was 5 and 50 kilowatt - hours when operating the electroosmotic filtration cell at potentials of 20 and 100 volts , respectively . calculated filtration area of about 10 square feet per ton of slime treated per day was required to thicken the slime from 15 to 35 percent solids .

Jan 1, 1964

Major activities of the Bureau of Mines Explosives Research Center during fiscal year 1965 (July 1, 1964, to June 30, 1965) are reviewed briefly. Part 1 summarizes significant accomplishments of the projects that were active during the report period. Part 2 presents short abstracts of the publications that appeared in the Bureau series and in other media during fiscal year 1965. Publications issued after June 30, 1965 are noted where pertinent in footnotes but are not abstracted.

Jan 1, 1966

By F. S. Crawford

A large number of operators of various industries in the United States do not appear to realize the great returns in dollars and cents which result from intelligently directed safety work . Managers of co 1 mines , metal mines , open-pit mines , quarries , steel mills , cement mills , oil rei meries , iron works , or other industrial operations , should by all means realize the great waste resulting from accidents , in order to appreciate the necessity for a continuous accident -prevention policy . While the prevention of accidents is worth while from the humanitarian standpoint alone , it has an equally important economic side , and before our mining industrial operations will be made as safe as they should be , it is apparent that this dollars and cents viewpoint must be given full recognition in order to bring before many of the men who run the industries the great importance of this phase of industrial management . : There is a tendency upon the part of the opera or who has not given thought to the cost of accidents ( and there are many mining operators of this type) to insure his company against compensation losses and against catastrophes for which he can secure insurance , and think he has done his duty ar an executive . Even though industrial operations were not compelled to pay compensation , and even if the management were not moved by humanitarian motives to try to stop accidents , it would pay many times over to carry on accident prevention work vigorously and continuously. : In some parts of the United States , the state compensation and insurance requirements are such that the operator does not receive a reduction in his insurance rate per men employed upon having made safety installations or upon having achieved a reduction of accidents in his plant . Under such conditions the management frequently does not feel encouraged to emert much effort in bettering the accident rate . However , when the responsible officials of a company realize the much greater harm to an operation which results from doing no accident - prevention work , and the great benefit in reduced costs which usually follows effective safety work , they should be inclined to do almost everything possible to reduce accidents , regardless of considerations as to accident compensations . There are enough indirect costs resulting from accidents to wreck many types of business ; excessive accidents result in disorganization and failure , while immunity from accidents usually means a smoothly running efficient organization .

Sep 1, 1930

Although alternating-current (a.-c.) power systems and equipment have been used in coal mining for many years, most mines in the United States are powered mainly by direct current (d.-c.). There are several logical reasons for this, but the use of d.-c, equipment is, in most instances, a direct outgrowth of the original practice of using such power for haulage systems. For traction equipment such as the electric trolley locomotive the d.-c. motor has ideal operating characteristics, and thus it has been widely used for haulage locomotive service. The first efforts at electrification of coal mines started with the haulage system and from there branched out to include the many types of electrically powered mining machinery used in the industry today.

Jan 1, 1960

By Arnold B. Hubbard

A thermal decomposition study of the kerogen in three Colorado oil shales was made at different temperatures by heating the shales in the absence of oxygen at atmospheric pressure and measuring the decomposition products (gas, oil, and bitumen) formed. From these data the specific reaction rates, "k", for the thermal decomposition of kerogen were determined for each temperature studied, making it possible to calculate the time required to accomplish a given amount of decomposition within the temperature range. The influence of temperature on reaction rates was presented by plotting the data according to the Arrhenius equation, thus providing a means of estimating the values of "k" for any temperature within the range of this study. It was found that the specific reaction rates for the thermal decomposition of the kerogen in the three sampler were comparatively equal at corresponding temperatures.

Jan 1, 1950

By R. R. Nothdurft

The internal friction of eight single crystals of magnesium with orienta-tion ranging from 10° to 84° was measured at 33.5 kc and 272° C, and the results were interpreted in terms of the pinned-dislocation model proposed by Granato and Lucke. Results show that the strain-amplitude-dependent decrement varies with orientation in a manner predictable by the G-L model. Different values of strain-amplitude-independent decrement were observed at different orientation angles, but correlation with the theory was not conclusive. Problems and steps for further study are discussed.

Jan 1, 1965

By William H. King

The Nevada Massachusetts tungsten deposits (fig. 1) are in the Mill City Mining District in north-central Pershing County, Nev., about 37 miles southwest of Winnemucca. Contact metamorphism of thin limestone beds within a series of metamorphosed sedimentaries formed scheelite-bearing ore bodies. These deposits are distributed over a wide area. A Bureau of Mines development program was started January 11 d was completed on July 25, 1941. This work was centered on the outer and less explored beds in the district and comprised trenching, sampling, and diamond drilling. Exploratory work was done in cooperation with the U.S. Geological Survey. Project work substantially increased the reserve tonnage of marginal ore in three of the areas explored and proved the nonexistence of tungsten in a fourth area. The following pages summarize the history of the district, outline property ownership, and describe physical features and ore deposits. The plan and results of the work performed by the Bureau of Mines are presented along with geologic and topographic maps, assay maps, and diamond drill-hole logs.

Jan 1, 1950