Search Documents

By Charles L. Ross

A successful placer mine is being operated by the E. T. Fisher Co. on Rock Creek in the South Pass mining district at Atlantic City, Wyo. About 2,800 cubic yards of gravel is dug daily by a gasoline-driven dragline shovel with a 1 1/4-yard bucket and washed in a movable plant with a gold-dredge trommel and standard-dredge sluice boxes; the total cost is about 12 cents per cubic yard. The gold-bearing gravel occupies a narrow valley between two low ranges, of hills. The ground is covered by brush and willows, which are cleared of in the fall by burning after the leaves have dried. The elevation at the mine is 7,600 feet above sea level.

Jan 1, 1935

By Avery H. Reed

ALABAMA'S mineral industry continued to expand. This was a record year for many commodities, with expansion in almost all industries. New records were established for the production of native asphalt, fixe clay, miscellaneous clay, kaolin, bentonite, lime, scrap mica, salt, sand and gravel, crushed limestone, crushed marble, and tale. Among the States, Alabama ranked second in the production of bauxite, third in the production of scrap mica and native asphalt, and fifth in iron ore. The mineral industry of Alabama was dominated by the mining and processing of coal and stone, the manufacture of cement, and the production of crude petroleum, which together comprised 87 percent of the total value of production, compared with 86 percent in 1963. The iron ore industry continued to decline. This was the first year in which consumption of imported iron ore exceeded the consumption of domestic iron ore. The coal industry recovered from the slump caused by the abandonment of red iron ore mining by United States Steel Corp., and production expanded 17 percent, for the best year in coal mining since 1948. During the year, the one-billionth ton of coal was mined within the State.

Jan 1, 1965

By R. August Heindl

[A proposes process for recovering manganese from open-hearth steel-plant slogs is indicated by the flow diagram shown in figure 1. Investigation of the process, the laboratory development of which was reported previously,4/ was expanded to a larger scale. Mixtures of flush slags and limestone were proportioned to have molar [SiO2] ratios of 1.5 to 2.2 and were fired at temperatures up to 2,400° F. In an oxidizing atmosphere. This produced clinker consisting principally me various combinations of the oxides of manganese, iron, aluminum, and magnesium aloe with a dicalcium silicate phase containing the phosphorus. Some tests were made with a continuous sintering machine of the traveling-grate type, but a rotary kiln was the most satisfactory apparatus for this operation. Material was fed at 150 to 200 pounds per hour after first being agglomerated either on the sintering or else binder extruding and drying finely ground mixture of the sing, limestone, binder, and water. Tests with slag; from tree different source indicated overkill manganese recoveries of 65 to 80 percent by ammoniacal-ammonium-carbonate leaching.]

Jan 1, 1955

By J. P. Morris

A diphenyl ether calorimeter for measuring high-temperature heat contents of ferrous alloys and iron-and steelmaking slags was constructed and calibrated with specimens of molybdenum, alumina, and platinum that were heated to temperatures ranging from 1,720° to 1,875° K. The standard deviation of the calibration measurements was 0.37 percent. By measurements of the enthalpy of delta and liquid iron, the heat of fusion of iron was found to be 3,298 ±100 cal per mole.

Jan 1, 1966

By W. R. Hardwick

This Information Circular describes copper mining and concentrating methods, practices, and costs at the Silver Bell Unit of American Smelting and Refining Co., Pima County, Ariz. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. The Silver Bell mining district, one of the older districts in Arizona, is in the western part of the Silver Bell Mountains in Pima County, about 40 miles west of Tucson and about 20 miles southwest of Red Rock, a station on the main line railroad of the Southern Pacific Co. The Oxide and the El Tiro open-pit mines of the American Smelting and Refining Co. are in the district (fig. 1. The principal ore deposits are in T. 12S., R.8E., Gila and Salt River base line, at an altitude of about 3,000 feet. The present town of Silver Bell, established in 1952, is reached by a paved highway, the Avra Valley road, that turns west from Highway 84 at Plata siding near Rillito and extends westward 25 miles to the townsite (fig. 2). The present town is about 5 miles southeast of the old town of Silver Bell that flourished from 1900 to 1930.

Jan 1, 1963

By W. R. Hardwick

This Information Circular describes copper mining and concentrating methods, practices, and costs at the Silver Bell Unit of American Smelting and Refining Co., Pima County, Ariz. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. The Silver Bell mining district, one of the older districts in Arizona, is in the western part of the Silver Bell Mountains in Pima County, about 40 miles west of Tucson and about 20 miles southwest of Red Rock, a station on the main line railroad of the Southern Pacific Co. The Oxide and the El Tiro open-pit mines of the American Smelting and Refining Co. are in the district (fig. 1. The principal ore deposits are in T. 12S., R.8E., Gila and Salt River base line, at an altitude of about 3,000 feet. The present town of Silver Bell, established in 1952, is reached by a paved highway, the Avra Valley road, that turns west from Highway 84 at Plata siding near Rillito and extends westward 25 miles to the townsite (fig. 2). The present town is about 5 miles southeast of the old town of Silver Bell that flourished from 1900 to 1930.

Jan 1, 1963

The overall objective of this study is to gather operational data from selected surface coal mining systems in the United States, and to assess the potential production and economic capacity of the systems. The study includes: four mines, each using a different mining technique and different equipment. One mine was selected from each of the major coal fields: Midwestern, eastern,, northwestern, and southwestern. The Midwestern Mine is located in the Central Plains and produced 1.45 million tons of raw coal during the study year The Midwestern Mine uses the area mining or box-cut technique. A large in-pit shovel and a bucket wheel excavator are used to remove the overburden. Coal is removed by a loading shovel and transported to the dumping point by large off--highway trucks.

Jan 1, 1975

By John D. Bradley

Stibnite is 76 miles east of Cascade, Idaho, which is 78 miles due north of Boise. The altitude at Stibnite is 6,500 feet, and between Cascade and Stibnite the Forest Service road crosses two summits - Big Creek at 6,800 feet and Warm Lake at 7,300 feet. The ownership of most of the Meadow Creek group of 190 claims, which is optioned by the Bradley Mining Co from the United Mercury Mines Co. may be traced back from their consolidation by the United Mercury Co. through ownership by prospectors and small promotional companies to the discovery of the Thunder Mountain district in 1900 by the Caswell brothers.

Jan 1, 1942

This publication summarizes the research (in-house and contract projects) programmed by the Bureau of Mines for fiscal year 1984 (October 1, 1983-September 30, 1984) under its Health and Safety Technology Program. The objective of these projects is to provide an ordered and sequenced advance toward the Bureau's overall goal of providing the systems technology required to create a more healthful and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1983

By Robert J. Hundhausen

During the early part of World War II , it appeared likely that supplies of chromite for United States industry might become critically short . As a part of the ensuing search for new sources of domestic chromite supply , the chromite - bearing black sands along the coast of southern Oregon were hurriedly investigated by State and federal agencies and by private interests , These investigations led to a decision to begin exploitation of the deposits immediately . A government stock- piling program was put into effect , a concentrator was financed by the Defense Plant Corporation , two privately controlled companies were encouraged to start mining operations , and the Bureau of Mines and the Geological Survey were authorized to search. for additional reserves of minable ore .

Feb 1, 1947

By H. B. Freaman, C. L. Colburn, C. M. Bouton

"The mine telephone has been perfected to such an extent that it is giving satisfaction in most mines were the wiring is well insulated. Very often the telephone cannot be depended upon on account of falls of rock, grounding due to worn insulation or extreme dampness. In the event of a disaster it frequently happens that the mine telephone system is put out of commission by the agency that causes the disaster, at the time when it is most urgently needed. On this account the mining industry is interested in any kind of telephone system that can be counted upon in an emergency. Many requests have been received by the Bureau of Mines to devise means of utilizing wireless methods for this purpose.The results of some preliminary experiments conducted by the writers at the Bureau of Mines experimental mine at Bruceton, Pennsylvania, in the ordinary sending and receiving of radio waves through earth strata are described below. The experiments were made in cooperation with the Westinghouse Electric end Manufacturing Co., which assigned to this work three of its radio engineers, C. A, Boddie, E. C. Douglas, and F. D. Fessler,The preliminary experiments consisted first in receiving signals from without the mine by means of a receiver located inside the mina, and second, both sending and receiving messages underground through the strata. It was found that with a receiving instrument set at a point 100 feet underground, signals from KDKA station, of the Westinghouse Electric and Manufacturing Co. East Pittsburgh, Pa., could be heard distinctly. Station KDKA is at a distance of about 18 miles from the experimental mine. About 50 feet from the receiving station used in this test was a 6-inch bore-hole from the surface, lined with iron pipe and containing electric light wires which extended therefrom through-out the mine. The presence of these wires evidently assisted greatly in the reception, for when the receiving set was carried to another point in the mine removed from wires and tracks the signals were barely audible through 50 feet of cover. The fact that signals were detected, however, even though faintly, is sufficient evidence of transmission through the ground to encourage further experimenting.In sending waves underground the Westinghouse 20-watt B.T. model T.F. transmitter was used in such a manner as to send out continuous waves of 200 to 300 meters length."

Oct 1, 1922

Objective: To provide a safe, practical, cost-effective method for measuring coal rib thickness during highwall mining.

Jul 1, 2008

By G. W. Jones

An important activity of the Bureau of Mines is the promotion of safety in mining and industry. As a part of this program, the Bureau determines the explosion hazards of combustible gases, vapors, and solids and investigates means of controlling and preventing explosions. The limits of inflammability (explosive limits) of combustibles are not only of theoretical but also of practical importance, because many industries at one time or another contend with explosive mixtures of combustible gases or vapors in their manufacturing processes. At present many new organic compounds are being manufactured, transported, and used in huge quantities which a few years ago were only laboratory curiosities.

Jan 1, 1941

By Charles Seitz

The Bureau of Mines has modified its parts-per-billion helium-4 analyzer to improve the analytical capabilities of the instrument. The modifications resulted in the following improvements: (1) The analytical precision of the instrument for 10 consecutive analyses was improved to ±1 ppb at the 5,000-ppb helium-4 level, (2) the helium-4 sensitivity was increased almost tenfold, and (3) the minimum detectable limit for helium-4 was improved to 0.5 ppb. The modifications made to improve the instrument included replacing the ion-source control circuit with a direct-current solid-state design, controlling the temperature of the ion source, stabilizing and reducing the pumping rate of the vacuum system, and optimizing peak integration.

Jan 1, 1986

By Virgil Miller, Glenn L. Allen

The purpose of this report is to present a comprehensive review of the technology of alumina and aluminum production in the former Japanese Empire , which consisted of the Japanese Home Islands and her dependencies , Formosa , Manchuria , and Korea . Pertinent background material and statistics are given when deemed necessary to make the report self - contained and to make clear the factors underlying Japan's tremendous accomplishments in the production of aluminum .

Apr 1, 1949

By W. W. Agey

Past investigations on waterborne impurities in the flotation process have been concerned primarily with the treatment of specific ores with particular local waters. Although some anions and cations present in water are known to react with flotation reagents, a definitive study has not been made on the effect of such common ions upon the flotation process. This report describes the fundamental research undertaken to define and measure the adverse and/or beneficial effects of different concentrations and combinations of several common anions and cations when oleic acid is used to froth-float limestone from a pulp of quartz and limestone. Research on the effect of waterborne impurities upon the flotation process was composed of two equally important phases. The first phase comprised development of a procedure for floating limestone from quartz that would give the same results in test after test. Some difficulty was encountered, but once such a procedure was developed, the second phase, comprising study and measurement of the effect of various ions c on to natural water upon the flotation of limestone, was quickly completed.

Jan 1, 1963

By A. Visnapuu

The Bureau of Mines, as a part of its goal to minimize occupational hazards associated with mining and mineral processing operations, has developed and field tested a compact exhaust air muffler for mechanized, jumbo-mounted pneumatic rock drills. The muffler is constructed of 1/8-inch sheet steel and has nominal dimensions of 1-3/4 by 9 by 13 inches. A directed air passage, flexible neoprene baffles, and an expandable slit-type outlet are incorporated to reduce drill exhaust air noise and eliminate muffler icing. Field tests in actual mining operations showed a l5-dbA reduction in exhaust noise and an 8-to 12-dbA reduction in overall drilling noise with no icing problems or decrease in drill performance. Data are presented on muffler construction, laboratory, and field test results.

Jan 1, 1979

By R. G. Warncke, J. H. East, D. Harrington

The mining industry of the United States has long been severely criti- cized because of its high rate of accident occurrence, not only as compared with other industries of the United States but also with the mining industries of other countries, particularly Europe. Statistics, often not strictly com- parable, indicate that the accident-frequency rate in all mining is currently about three times and the accident-severity rate is about seven times as great as the average for general industrial work in the United States. These fig- ures are by no means comforting to humanitarian mining men, irrespective of their status in the industry, and they constitute a challenge that certainly cannot continue to be ignored much longer. The picture becomes much darker when the above statistics are augmented with data indicating that on an exposure basis our mines (more particularly our coal mines) have accident rates two, three, or even more times as great as more or less similar mines in Europe, particularly England, Wales, Belgium, France, and Germany. The sting is alleviated to some extent by the knowledge that our coal mines produce about 4 to 5 times as much coal per man day as is produced in at least some European mines. However, all of these foreign acci- dent statistics should be analyzed carefully before we become very much con- cerned about them, because they are not strictly comparable, for several reasons, not the least of which is the fact that foreign methods of compiling or recording accident statistics often differ materially from ours. Moreover, foreign mining and other conditions are definitely dissimilar to ours in many phases, and numerous other factors affect the comparability of foreign mine- accident statistics with those of the United States. Unquestionably, it should also be taken into consideration that the accident rate of the 140,000,000 or more constituting the populace of the United States as a whole is much higher than that of any other major country in the world and is two, three, or more times the rate of the European countries that have more favor- able mine-accident rates than those of the United States (table 1). Moreover, it is significant that the mine-accident-severity rate of British mines is about six times the average accident-severity rate of the major industries of the British Isles, or but little more favorable than the comparable figures in the United States; namely, that mining has an accident severity rate about seven times the average of about 30 of the major industries of this country.

Apr 1, 1949

By J. Fletcher Smoak

Consumption of abrasive materials in the United States increased 22% in value over that of 1982 to $320 million; of which, 59% was manufactured abrasive, 35% was industrial diamond (natural and synthetic), and 6% was natural abrasive. Production value of natural abrasives, excluding industrial diamond, remained virtually unchanged. Production of crude tripol, a porous siliceous rock, decreased slightly; however, shipments of processed tripoli increased 13% in quantity and 32% in value. Production of garnet, an abundant iron-aluminum silicate, continued to increase primarily because of further increases in production from one plant that had completed an expansion program in late 1981. Production of special silica stone, both crude and finished, decreased in 1983 because of reduced demand for oilstones

Jan 1, 1984

By G. E. Bobeck

The first year's work of a proposed three-year study of the effects of the exposure of coal mine roof rocks to the mine atmosphere has been completed. The project has been terminated. The goal of the project was to determine if possible the mechanism or mechanisms by which coal mine roof rocks interact with the mine atmosphere and weaken, and coupled with mechanical stresses, ultimately fail. The scope of the study was limited to the effects of environmental factors on the deterioration of the rocks. While mechanical stresses may play an important role in the interaction of environmental factors, stress effects were excluded from the study. In order to study the effects of environment on coal mine roof rocks, samples were obtained from several coal mines in the western states. The rocks forming the roofs of most of the mines visited were shales of varying composition. These shales were subjected to numerous tests to determine how the rocks changed with time after exposure. In addition, the identity of the minerals present in the shales was determined by x-ray diffraction analysis and by thermal analysis as well as by optical microscopy

Jan 1, 1973