Search Documents

Federal lands often contain extensive mineral resources and decisions affecting access to those lands are made with knowledge of the possible minerals-related consequences. Information is provided to the Bureau of Land Management (BLM) in this report for use in preparing environmental impact statements on the Western Mojave Management Area (WMMA) and the Desert Tortoise Priority Habitat (DTPH). To augment U.S. Bureau of Mines (USBM) efforts such as the Mineral Assessment of the Planned Foil Irwin Expansion, Modified Silurian Valley Alternative, San Bernardino County, California which is in progress, and the Economic Analysis of the Minerals Potential of the East Mojave National Scenic Area; California, the USBM studied mineral deposits and estimated the potential impacts of mining in a segment of the California desert; the 8.7-million-acre WMMA, an area which includes the 1.2-million-acre Desert Tortoise Priority Habitat (DTPH). In addition, this information is intended to assist administrators, legislators, and the concerned public in understanding the economic importance of mineral resources in the California desert, especially that portion designated as the WMMA. See figure 1.

Jan 1, 1993

By Paul J. Barrett

The Bureau of Mines evaluated a sulfurous acid-sulfuric acid process for recovering alumina from clay, in which clay is leached. successively with sulfurous acid and sulfuric acid. The resulting aluminum sulfite and aluminum sulfate solutions are combined and heated to produce a basic aluminum sulfate and sulfur dioxide. Alumina is extracted from the basic aluminum sulfate as sodium aluminate by leaching with dilute sodium hydroxide. After desilication, sulfuric acid is used to precipitate alumina as alumina trihydrate, which is then calcined to alpha-alumina. The estimated fixed capital cost for a plant producing 1,000 tons per day of alumina is about $74 million on a 1971 basis. For comparison with previous alumina-from-clay evaluations, the estimated fixed capital cost for the plant is about $67 million on an M and S Chemical Equipment Index basis of 24.0.0, which is equivalent to a 1960 cost level. Because the operating cost is highly dependent on fuel and electric power costs, graphs are included to show the effect of these items on the operating cost. On a 1971 basis, with natural gas costing 35 cents per million Btu and operating labor costing $4 per hour, the estimated operating cost is about $100 per ton of alumina. On a 1960 basis, with labor costing $2.30 per hour and natural gas costing 25 cents per million Btu, the estimated operating cost is about $86 per ton of alumina.

Jan 1, 1973

By M. O. Magnuson

As part of an experiment in the restoration of lands strip-mined for coal, revegetation studies were conducted at three backfilled strip-mine sites in north-central Pennsylvania. The sites were subdivided into plots that were given varying amounts of lime and fertilizer. In tests conducted cooperatively with State and Federal agronomy experts, the plots were then planted with a variety of trees, shrubs, and grass-legume mixtures. Initial tree and shrub survival was not appreciably affected by lime and fertilizer applications where the spoil pH was above 4.5. Of 14 species of trees and shrubs tested, Norway spruce, black locust, Japanese larch, pitch pine, and white pine were the hardiest. The ground-cover percentage of grass-legume mixtures in the second growing season was substantially increased by using lime and fertilizer. Mixtures comprised partly of fescue were the most satisfactory.

Jan 1, 1968

By Charles C. Myers, Robert M. Doerr

The apparatus described was developed for determining the kinetics of gas - solid reactions at high temperatures by measuring the volume of gas consumed with respect to time . This apparatus consists essentially of a horizontal precision- bore glass tube connecting a small reaction chamber in a furnace to a large constant - temperature reservoir . A drop of mercury in the tube separates the two sides of the system and serves as an indicator that moves at a speed proportional to the rate of gas consumption . The sensitivity of the apparatus depends inversely on both the density of the gas in the system and the cross - sectional area of the tube ; with a tube having an area of 0.079 cm² , the sensitivity for oxygen at 308 ° K and 0.5 atm is 20 cm/mg . The reproducibility of data with the volumetric apparatus is good .

Jan 1, 1964

By Robert F. Holub

The Bureau of Mines has evaluated four working-level radiation-measurement methods and optimized them from the inherent and statistical error standpoint. Optimization with respect to various sampling and measurement times yielded no marked improvement over the existing methods. However, when appropriate approximations are made and evaluated, these two-measurement methods can be reduced to simple formulas, eliminating a need to use nomograms. These modified methods also have improved inherent error characteristics. A new method--a combination of two existing methods--with improved inherent and statistical errors has been suggested. All the pertinent equations are given, together with the computer program, so that any two-measurement method can be readily evaluated.

Jan 1, 1980

By W. J. Fene

It is often desired to obtain samples of air in places where collection by ordinary methods is not feasible, as in shafts amore means of descent or ascent are not provided, in sewer manholes, in gas or water wells, in empty oil tanks, and in sealed areas in mines. Heretofore, when such sampling was required, it was necessary to utilize the aspirating method, which was not always satisfactory; and to obtain samples of air in deep shafts, it was necessary to use long sections of rubber tubing, which was not always available. DESCRIPTION OF NEW DEVICE A new method or "device" employs a common snap-type mousetrap to break the neck of a vacuum tube at the place where it is desired to collect the sample (see fig. 1). A mousetrap is mounted on one end of a block of wood 11-3/4 by 3 by 3/4 inches in such camper that a lead weight attached to the trigger hall spring the trap when the device is given a sharp jerk. A vacuum tube is placed on the other end of the block and held in place by a strong rubber band. A strip of corrugated rubber is placed on each side of the grooved block to prevent the tube from clipping when the sample is taken. An adjustable shoulder, provided with a rubber cap, is pieced se that the neck of the vacuum tube will rest on it. The shoulder is made adjustable to accommodate various sizes of tubas and to keep the neck of the tube from breaking tee far back from the point. A metal handle is fastened to one end of the block, with a hole in the end through which the brass wire used for lowering the device is tied. The device is enclosed by a strong wire-gauge covering, hinged on one side and so arranged that it can be locked shut on the other side. This covering prevent: breaking of the tube while it is being lowered or raised in a shaft or other place. Brass wire of not less than 22 gage should be used for lowering the device. A detailed drawing of the device is shown in figure 2.

Jan 1, 1940

By Arne Landsberg

The Bureau of Mines has undertaken research to elucidate the chemistry involved in the efficient recovery and control of minor elements in base metal smelting operations. These elements should be effectively recovered not only because they have commercial value, but also because of their potential hazard to workers' health and the environment, if they are not controlled during processing. Cadmium, a minor metal in zinc ores, is the subject of this report. The roasting step of the complex zinc-smelting process was chosen for investigation because of the high potential for removing cadmium by volatilization during this primary stage. Commercial roaster feed materials were used to determine the sequence of reactions and the effect of these reactions on the volatilization of cadmium. Electron microprobe examination of both the commercial roaster product and oxidized sulfide solid solutions prepared in the laboratory showed that oxidized iron was of prime importance in preventing cadmium volatilization. The mechanism by which iron prevents cadmium volatilization is proposed, and a preheating technique is recommended for more effectively recovering cadmium prior to roasting.

Jan 1, 1981

By D. E. Traut

A fluidized, countercurrent ion-exchange system was developed, operated, and evaluated by the Bureau of Mines in support of its objective to help assure an adequate uranium supply for future national needs. The system consisted of integrated multiple-compartment absorption and elution columns in which the solution flows are continuous, except for short periods when resin increments are withdrawn. The exchange of uranyl sulfate between a simulated acid-leach-uranium solution and a strong-base, ion-exchange resin was studied, together with subsequent elution using an acidified sodium chloride solution. The effects of the number of compartments, compartment height, amount of resin withdrawal, solution flow rate, and column diameter were investigated. Also examined were the kinetic and equilibrium relationships for the absorption and elution steps. The experimental data indicate a strong interdependence between variables. Solution retention time appears to be a major limiting variable in the absorption process, while resin residence time is the determining factor in the elution process. The columns system was efficient over a range of conditions, but close control was needed for optimum operation.

Jan 1, 1978

By J. R. Thoenen

[Since the publication of the preliminary report on this subject in July, 1927, (The Wire Saw in Slate Quarrying, Preliminary Report, Serial No. 2820, by Oliver Bowles) the wire saw has been in constant daily operation at the quarry of the Colonial Slate Company. Luring this time between twenty end thirty successful cuts have been made varying in length from forty-five to ninety-two feet and in depth from six to ten feet. No accurate time records have been kept on these cuts but they have totaled over 12,000 sq. ft. of area and required 19,000 lineal fact During these cuts the average speed of cutting has risen from the 12.8 sq. ft. per hour obtained in the original recorded tests to between 15 and 20 sq. ft. per hour, with the present rate running very close to 20 sq. ft. per hour at this quarry.]

Jan 1, 1928

By J. J. Forbes

The rapid increase in the quantity of coal being mined by stripping methods is one reason for the increased interest evinced by safety and other agencies in the hazards that are inherent in this Method of mining. The coal-mining laws of some States contain general provisions governing the mining of coal by open-cut methods, but none contains a complete list of specific safety regulations or laws for-the safe operation of such mines. The cool-mining laws of one State empower the head of the coal-mining inspection organization to proscribe regulations for coal-stripping operations and gave him the authority and power to enforce the rules and regulations promulgated by him.

Jan 1, 1944

By Henry E. Perlee

In a Bureau of Mines study two-dimensional mathematical equations were solved that describe the transient thermal response of a rock dust particle in a cloud of similar particles in a gas flame's preheat zone subject to a radiant field from the approaching flame. The description includes both radiant energy absorbed and emitted by the particle and thermal conduction inside the particle and into the surrounding gas environment moving relative to the particle. Two situations were studied; in one the radiant energy incident on the particle is converted to thermal energy at the particle surface, and in the other the radiant energy is converted to thermal energy uniformly over the volume of the particle. The result of the study showed that for a 10-µm-radius particle, a 200-mg 1-1 loading density, and a flame approach velocity of 30 m sec-1, the particle temperature rise was twice that previously calculated by Singer and Cook based on the model of Essenhigh and Csaba. It was further established that under the conditions examined a rock dust particle temperature never increases more than about 200 K before crossing the flame front.

Jan 1, 1976

By H. C. Ko

Calorimetric determinations of low-temperature heat capacities and the standard enthalpy of formation were made by the Bureau of Mines for aluminum sulfide, A12S3. The standard entropy (S°), enthalpy of formation (?Hf°), and calculated Gibbs energy of formation (?Gf°) at 298.15 K are 27.93±0.05 call deg-mole, -155.6±0.9 kcal/mole, and -153.0±1.0 kcal/mole, respectively.

Jan 1, 1976

By J. E. Hamak

This publication contains analyses and related source data for 162 natural gas samples from 15 states and 4 foreign countries. Of the total samples, 154 were collected during calendar year 1992. The remainder were collected earlier, but releases granting permission to publish were not received until 1992. None of the analyses have been previously published in annual reports. All samples were obtained and analyzed as part of U.S. Department of the Interior, U.S. Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free-market economies. This survey has been conducted since 1917. The analyses published herein were made by mass spectrometer and chromatograph.

Jan 1, 1993

By W. W. Adams

During the calendar year 1927 the United States Bureau f Mines conducted, for the third consecutive year, a safety contest among more than 250 mines and quarries. Aside from its underlying purpose to promote safety, the object of the contest was to learn which mine or quarry had completed the year's work with the smallest proportionate loss of time from accidents to its employees. Competing companies were grouped into five classes, namely, anthracite mines, bituminous teal mines, metal mines, nonmetallic mineral mines, and quarries and open-pit mines. To the winning company in each group was awarded the bronze trophy "Sentinels of Safety," the gift of The Explosives Engineer magazine. The winner in each group was the mine or quarry whose record showed the smallest loss of time from accidents in proportion to the total amount of time worked by 411 employees. This proportion is designated the "accident-severity"3 rate; it indicates the number of days of disability resulting from personal injuries per thousand man-hours of work performed by all employees. Each company's standing was determined by the Bureau of Mines from detailed records furnished by the contestants. Records of the leading companies were made known to a committee of seven men well known to the mining industry but not connected with the Bureau of Mines. This committee selected the winning companies in accordance with rules governing the Competition. According to the contest rules, the competition for the trophy was restricted to mines employing at least 50 men underground and to quarries and open-pit mines employing at least 25 men in the pit. As several plants fell below these figures during the year, their records could not be considered in connection with the award of the trophy. Figures covering these plants are, however, included in the attached tables.

Jan 1, 1928

By W. A. Cole

The sulfur shortage that existed during the Korean conflict stimulated interest in coal measures as possible sources of sulfur. One of the areas brought to the attention of the Bureau of Mines was in Marion County, Iowa, where comparatively high-sulfur coals and other marcasite-bearing strata were known to occur. A Bureau of Mines engineer inspected the marcasite occurrence on December 4, 1954; this prompted further work on the Iowa coals and associated formations as a source of iron sulfides. An investigation of the Iowa high-sulfur coals was undertaken including core drilling, field reconnaissance, and compilation of data pertinent to consideration of the following: 1. Upgrading Iowa coal by mechanical cleaning and the feasibility of recovering sulfur from coal brasses. 2. Possibility of processing the high-sulfur coals by adaptation of methods employed in processing industrial gases to produce sulfur and sulfur products. 3. Possibility of finding concentrations of iron sulfides in associated rock formations in sufficient quantity for economical recovery.

Jan 1, 1957

By Donald O. Capstick

A mineral survey of the 520-acre Quigg West Wilderness Study Area (MT-074-155) was conducted by the U.S. Bureau of Mines in 1986 at the request of the U.S. Bureau of Land Management in order to evaluate its identified mineral resources. The Wilderness Study Area is in Granite County in western Montana about 16 miles northwest of Phillipsburg and 27 mi les northeast of Hamilton, MT. Stony Mountain, a study area on lands administered by the U.S. Forest Service, is about 1 mile to the south-southwest and was studied concurrently. No mineral resources were identified in the Quigg West Wilderness Study Area, but high grade gold assays, as much as 1.24 ounce gold per ton, were obtained at the one prospect found. Samples from four workings contained significant gold; minor silver, molybdenum, and copper were also present. The prospect containing the narrow and discontinuous gold-bearing quartz vein straddles the south boundary of the Wilderness Study Area. The shear zone containing the vein projects toward the old Crescent mine, about 4.5 miles to the south, which shows a similar geologic structure.

Jan 1, 1987

By Douglas C. Peters, Valois R. Shea-Albin, Dennis R. Dolinar

An accurate assessment of the vertical stress on a coal seam at depth is important for mine design. Vertical stress calculation techniques presently available either are not sufficiently accurate or cannot handle complex surface topography. Therefore, the U.S. Bureau of Mines developed a computerized method to calculate vertical stress exerted on surfaces at depth that includes the effect of topography. Two input data sets are required: a digital elevation model containing topographic elevations and a coal seam file defining coal seam elevations at depth. Boussinesq's equation then quantifies the vertical stress resulting from topography. The computerized method was tested on a coal seam overlain by a complex topography where a vertical stress map encompassing several square miles was produced. Results show that depth mitigates the affects of surface topography, while the coal seam topography has a direct effect on the vertical stress. In comparison to the computerized method, the direct stress method overestimates stress under hills and underestimates stress under valleys. The largest difference between the two methods occurs under the steepest topographic relief. A limitation of the computerized method is that stresses cannot be accurately determined near an outcrop.

Jan 1, 1992

By E. A. Johnson

As part of its effort to reduce the environmental impact associated with mining and metallurgical operations, the Bureau of Mines used a modified form of the Environmental Protection Agency's Extraction Procedure toxicity test on copper reverberatory slags that contained low, medium, and high levels of the impurity elements As, Pb, Sb, Bi, and Zn. All tests resulted in extracts that did not exceed those limits published in the May 19, 1980, Federal Register; there-fore, these solid wastes were designated as nonhazardous for most landfill disposal situations. However, arsenic and lead levels disturbingly close to the allowable limits--and even higher levels of copper and zinc, for which there are no established limits--leached from the high-impurity-element granulated slags. These slags should be handled in such a way so as to minimize the possibility of water contamination. One baghouse dust was tested according to the EPA procedure and found to exceed the extract limits by a factor of 10. This solid waste may be considered hazardous.

Jan 1, 1982

By Ludwig Schmidt

Investigations conducted by the Bureau of Dines pertaining to the reduction of evaporation losses of petroleum have shown that such losses may be reduced 70 to 80 per cent by the use of vapor-tight tanks equipped with vacuum and pressure relief valves, and vapor-tight thief hitches. Additional studies have shown that it is often economical to supplement this type of construction with other measures that will reduce evaporation losses still further. Water-cooling systems, insulation, and light colored paints are the measures most often used in connection with vapor-tight tanks. Painting with light colored paints probably is employed in the greater number of cases. On account of the cost of insulation, or of installing water cooling systems, the use of these methods are restricted to tanks containing gasoline or crude petroleum with a very large content of low-boiling fractions. The effect of cooling systems has been discussed in a previous report.2 In choosing paints for tanks many factors must be considered. Probably the three most important are cost, protective value, and color. Many companies have adopted a standard color for all of their tanks in this way they reduce the initial cost of paint by buying in large quantities. The tank farms of such companies usually have a neat appearance, resulting from the uniform painting of all tanks. This procedure also has advertising value. Unfortunately, most of the paints used to protect steel are of the darker colors, usually red or black. These colors accelerate the rate of evaporation. Several companies have solved this difficulty by using a dark colored metal-protective paint as a primer coat, and a paint of any desired color for the final coat. Special metal-protective primers to be used under light-colored cover coats have been placed on the market by several paint manufacturing companies.

Jan 1, 1925

By Albert F. Baker

Techniques were developed and circuitry was assembled for measuring the total and volume resistances to the flow of electric current through solid specimens of anthracite. The two-, three-, and four-terminal test methods demonstrated the extreme sensitivity of resistivity to differences in anthracite characteristics and showed response to changes resulting from variations in structure, temperature, and moisture content.

Jan 1, 1966