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By J. G. Donaldson

Cobalt-tungsten binary deposits were formed in laboratory experiments by hydrogen reduction of the anhydrous mixed vapors of cobaltous chloride and tungsten hexachloride. The materials were sublimed in seperately heated zones of reaction tube and were transported in a stream of purified helium into the deposition section of the tube where the chloride gases were reduced to metal by a countercurrent flow of hydrogen. Heattreating of the near stoichiometric binary metallic deposits converted nearly all to the intermetallic compound Co3W, however, small quantities of both cobalt and tungsten remained. Mechanical tests showed that the tensile strength of heat-treated 75 percent cobalt-25 percent tungsten deposits was twice as high as that of similarly treated deposits of cobalt.

Jan 1, 1965

By Edmund S. Leaver

The Precious Metals Section is concerned primarily with ore-testing problems associated with precious metals and with the analysis and concentration of a large number of the strategic-mineral samples that have been included in the research program of the Bureau of Mines. During the fiscal year 1938-39, 30 projects were completed. The requests for this service are based upon the desire of the sponsor to obtain the best or most satisfactory method for maximum recovery of the minerals. In many instances it is a question of improving present milling practice, with due regard to utilization of present equipment. In others, the probable tonnage available maybe the deciding factor in the choice of a particular recovery method. Under all circumstances the results of tests axe prepared with the thought of aiding a competent metallurgist, familiar with local conditions, to formulate a practical flow sheet or to assist the mill operator to correct known losses. A microscopic examination for identification of the mineral constituents and their association in each ore is always a big help, in planning the tests and may indicate the reason for former troubles or assist with best procedure.

Jan 1, 1940

By Edmund S. Leaver

The Precious Metals Section is concerned primarily with ore-testing problems associated with precious metals and with the analysis and concentration of a large number of the strategic-mineral samples that have been included in the research program of the Bureau of Mines. During the fiscal year 1938-39, 30 projects were completed. The requests for this service are based upon the desire f the sponsor to obtain the best or most satisfactory method for maximum recovery of the minerals. In many instances it is a question of improving present milling practice, with due regard to utilization of present equipment. In others, the probable tonnage available maybe the deciding factor in the choice of a particular recovery method. Under all circumstances the results of tests axe prepared with the thought of aiding a competent metallurgist, familiar with local conditions, to formulate a practical flow sheet or to assist the mill operator to correct known losses. A microscopic examination for identification of the mineral constituents and their association in each ore is always a big help, in planning the tests and may indicate the reason for former troubles or assist with best procedure.

Jan 1, 1940

By A. M. Gaudin

A study of the consumption of reagents used in flotation gives useful data as to the market which employment of the flotation process creates for the manufacturers of the necessary chemicals and oils, and furnishes a useful clue to the trends in flotation practice influencing the choice of reagents used and the' extent to which new reagents are displacing less suitable older reagents. In the present investigation an attempt has been made to cover both of these phases of the consumption of reagents in flotation. Unfortunately, however, the data collected in tie various districts have not been equally informative; some operators have reported very completely both the consumption of reagents and the metallurgical results obtained therewith, while others were apparently unable to supply these figures in sufficient detail to meet the requirements of this investigation. RESULTS OF INVESTIGATION Table 1 gives the tonnage of ore treated by flotation, as reported. This table shows that flotation has been most largely used in the concentration of copper ores, next in complex lead-zinc ores, followed by lead ores, zinc ores, miscellaneous ores, and copper-iron ores.

Jan 1, 1929

By Alexander M. Gow

This paper summarizes a survey of fine-grinding practice in ore-concentrating plants throughout the United States, Alaska, Canada, Mexico, and Cuba as reported in the Bureau of Mines Information Circulars on milling methods. The survey covers 49 concentrators, which have a combined capacity of over 160,000 tons per day. In these plants 470 ball, rod, and pebble mills prepare material for flotation, gravity concentration, amalgamation, cyanidation, and air separation. The ores are those of gold, silver, copper, lead, zinc, molybdenum, feldspar, and pyrite. The metallurgy is that of the period 1928-32. Of these 49 concentrators, 36 are in the United States. They can treat 134,400 tons per day, and they have 326 fine-grinding mills. In the United States there are about 100 active or temporarily idle concentrators, exclusive of the many plants in the Tri-State zinc district, the washeries of the Lake Superior iron ranges and the Florida phosphate area, and small gold and silver concentrators. These 100 plants have an estimated capacity of 290,000 tons per day and employ about 650 ball, rod, and pebble mills. Consequently, since this paper covers about half of the production of this country it may be considered as particularly representative of fine grinding in ore mills in the United States.

Jan 1, 1933

By J. V. Batty

In the course of the investigation of manganese mineral occurrences in the United States, Bureau of Mines examining engineers collected several lots of ore from the Black Rock, Kramer, and. Morgan-Cromar properties, Tooele and Juab Counties, Utah. Extensive laboratory tests were made to determine the amenability of the ores to standard ore-dressing methods of concentration. The Black Rock claims 1 and 2 are 42 miles northwest of Jericho, Tooele County, Utah. A. J. Huber of Salt Lake City and Ross Rydalch of Tooele, Utah, are the owners. The deposit-is reported to be a definite manganese fissure vein in quartzite along which considerable shearing and cross fracturing have occurred. Laboratory work was conducted on a 2-ton sample of run-of-mine ore procured by a Bureau of Mines examining engineer and two smaller, higher-grade samples submitted by the owners as a result of later development. The Kramer deposit is described as a bed of manganese oxides in quartz. The property is being worked by L. E. Kramer, Tooele, Utah, and is 41 miles northwest of Jericho) Tooele County, Utah, approximately 1 mile north of the Tooele-Juab County line. A 1-ton run-of-mine sample was submitted for testing by the examining engineer.

Jan 1, 1952

By Charles H. Parr

A testing program was conducted to determine the suitability and reliability of adhesives and polycarbonate lenses for extended use in luminaires in mine environments. Polycarbonates were exposed, for periods up to 36 months, to four environments including ultraviolet light, humidity, intermittent water spray, and heat of either 180°F or 407 in various combinations. Rod impact tests on the exposed lens material indicated, that polycarbonate functions well under all 180°F environments and could be used with confidence for periods exceeding the test period, for as long as ten years, with a suit) able safety factor employed in design. The specimens exposed at 240°F showed decreased toughness after 24 months' exposure. Extrapolation of these data was deemed to be risky. A 462-day compatibility test between polycarbonate and six hydraulic fluids was run on stressed PC beams. One fluid caused beam breakage in less than one day, while three caused breakage at intermediate times. Two fluids exhibited essentially no effect on the PC when compared to a control. Epoxy and silicone adhesives were tested as lens adhesives and sealants. Three epoxy combinations tested showed low and erratic failure stresses. A room-temperature-cure silicone adhesive functioned extremely well for time periods up to 36 months and temperatures u2 to 240°F.

Jan 1, 1985

By W. C. Sanborn

The Bureau of Mines program of investigation and development of domestic mineral deposits had as its wartime objective the most effective immediate utilization of these resources in the interest of National security. Since the war, the results of individual projects are being prepared for publication as rapidly as practicable. Numerous chromite deposits were examined, among them those of the French Hill Mine in northern California. Situated 16 miles east of Crescent City, 76 miles from the nearest railroad shipping point at Grants Pass, Oreg., this deposit had a recorded yield of about l4,000 tons of metallurgical-grade chromite to the end of 1943. By the end of 1946, total production was more than 25,000 tons, averaging 43 percent Cr2O3, with a chrome:iron ratio of about 2.5:1.

Jan 1, 1948

By H. G. Iverson

The effects of adding boron and boron plus carbon to electrorefined vanadium were evaluated with respect to mechanical properties at low temperatures and response to heat treatment. Grain size was significantly decreased with the addition of 0.05 percent boron, the decreases ranging from 30 percent at 800° C to 75 percent at 1,100° C. Increasing the boron content resulted in only a small increase in strength at room temperature, but at 77° K, boron contents of 0.005 to 0.076 percent increased the yield strength of vanadium over 50 percent, from 70,000 psi to 110,000 psi. When boron and carbon were present together, the individual grain-refining effects obtained with either element were retained. Approximately a twofold increase in strength was obtained by age-hardening the alloys containing both boron and carbon. Alloys with only boron additions did not age-harden.

Jan 1, 1968

By F. S. LOTT, I. S. CULVER

The number of petroleum refineries in the United States decreased during 1948 from 390 to 375, continuing the trend to fewer units of larger individual capacity that has persisted since the peak in number of plants was recorded on January 1 , 1936. Large - scale construction of new processing facilities continued through 1948 with a resultant gain in daily crude-oil throughput capacity of installed equipment from 6,034,252 barrels on January 1 , 1948 to 6,438,995 barrels on January 1 , 1949. The capacity of the average refinery to process crude oil therefore increased during 1948 from 15,472 barrels daily to 17,171 . The principal areas of expansion of facilities were the strategic seaboard districts of the Texas and Louisiana Gulf Coast and the East Coast , and the important Indiana , Illinois , Kentucky, etc. , district that supplies markets in the upper Middle West region . These four districts accounted for 79 percent of the total new capacity added in the United States in 1948. The relatively small petroleum- refining industry of the Other Rocky Mountain district experienced a vigorous expansion in 1948 that will continue during 1949 . Capacity building on January 1, 1949 , amounting to 341,500 barrels daily, was 25,750 barrels lower than the comparable total on January 1 , 1948, but was the second highest on record . New construction was heavily concentrated in the Texas Gulf, East Coast , and Indiana -Illinois

Sep 1, 1949

By John Owens, Hamid Maleki

Efficient and safe use of mobile roof supports (MRS) depends on the interaction between the MRS and coal strata. Of particular interest to this study are the mechanics of strata deformation as influenced by geologic conditions, pillar extraction methods, and MRS load-bearing capabilities. To provide a better understanding of the mechanics of strata deformation, the authors have collected and reviewed measurements of convergence and stress in one western U.S. mine and have completed pseudo-three-dimensional, boundary-element modeling for two typical pillar-pulling plans. Stress distribution in the mine roof above pairs of MRS’s was calculated to demonstrate how MRS’s contributed to the control of roof block movements. It was shown that overall stress and roof-floor convergence patterns were most influenced by the stiffness of coal-measure rocks and by pillar-pulling sequences and layouts. MRS’s and other support systems play a critical role in controlling the stability of both the immediate roof and the middle roof for a distance of up to 18 m (60ft) above the seam. MRS’s provide unique ground control advantages over other types of secondary support by significantly reducing the time between mining and installation of secondary support. Although MRS’s are similar to posts in stiffness and capacity, they are more effective than posts under static loads because they can yield and still maintain loads at near-peak capacity, whereas posts fail and loose their ability to limit mine roof deformation.

By D. W. Frommer, L. Bonicatto, M. M. Fine

A mineral - dressing investigation was conducted to demonstrate the ability of an anionic silica - flotation process to produce high- grade concentrates from submarginal iron ores of the western Mesabi and Menominee ranges . Commercially available equipment and reagents were used . Samples from the Menominee range were exclusively from the Groveland , Mich . , mine and contained hematite as the chief iron - bearing mineral . Bench- scale investigations established that the anionic silica flotation method can function effectively on a variety of undeslimed ores . Continuous tests completed on one Mesabi semitaconite ore and on Groveland mill feed , have verified the validity of the bench research . The Mesabi samples yielded a concentrate containing 60.3 percent Fe and 6.0 percent Sio with an accompanying iron unit recovery at 90.5 percent . Iron recoveries from the mill feed ranged from 79.0 to 87.4 percent .

Jan 1, 1964

By B. W. Gandrud, G. T. Bator

The recent introduction of small coal jigs in Alabama to meet the needs of truck - mine operators for cheap and economical cleaning equipment marks another step in Alabama's pioneering record in the mechanical cleaning and preparation of coal . During the past 4 or 5 years a number of these small jigs , with capacity of 5 to 10 tons per hour , have been installed at Alabama truck mines and at a few truck mines in Illinois , Tennessee , and Pennsylvania . Most of the installations have been at mines that specialize in the production of domestic , stoker coal . This report describes three models of small jigs and includes performance data obtained recently on one of the models by the Bureau of Mines, United States Department of the Interior , in cooperation with the University of Alabama, Tuscaloosa , Ala . , for the purpose of comparing it with fullsize jigs on a performance basis . With literally hundreds of truck mines now in operation throughout the country , it has been assumed in preparing this report that there is widespread interest in the availability of small - scale inexpensive preparation equipment for use at such mines in the production of steam and domestic coal and in some instances coal for manufacture of coke . Practically none of the coal from Alabama truck mines is scld to coke - oven plants ; but in some sections of the country truck mines supply a considerable amount of coking coal, and the use of small, inexpensive washers at some of them might be very advantageous during the present war emergency from the standpoint of increasing pig - iron production through improvements in coke quality .

Aug 1, 1943

By Donald E. Redmon

This Bureau of Mines report reviews injury experience in the metallic mineral industries for 1966-67. For each of the years, 27 tables summarize disabling work injuries by department, source of injury, extent of disability, part of body injured, and nature of injury. Correlative information on employment, worktime, and operating activity is also presented.

Jan 1, 1973

By William D. Riley

In order to evaluate the corrosion resistance of zirconium in mineral extraction processes, such as a clay-hydrochloric acid leaching process for extracting alumina, the Bureau of Mines conducted corrosion studies in HCl-AlC13-FeC13 environments. A series of weight loss and electrochemical tests were conducted at 25° and 65° C in aluminum chloride (AlC13) plus hydrochloric acid (HCl) solutions containing 0 to 1,000 ppm ferric ion. It was determined that zirconium, which normally exists in a passive state in chloride-containing solutions, undergoes pitting attack in solutions containing more than 100 ppm of ferric ion. It is also shown that an oxide film prepared in air at high temperature offers protection in acid solutions containing levels of ferric ion from 300 to 1,000 ppm.

Jan 1, 1981

By M. S. Seehra, V. S. Babu, L. Farinash

"The diesel particulate matter (DPM), a constituent of the diesel engine exhausts, is known to be a potential carcinogen. 1- 3 Consequently, suitable methods to control/eliminate DPM have ·been under investigation in recent years. The DPM can be controlled by using fibrous ceramic traps. However, clogging of traps by DPM requires the impractical periodic trap replacement. Following the recent work by Garner and Dent,4,5 we are investigating the in situ use of microwaves to regenerate the ceramic traps, thereby eliminating the trap replacement step in this process. The use of microwaves instead of conventional heating for trap regeneration has the advantage of selective heating of the DPM instead of the trap, if the trap absorbs insignificant microwave power relative to the DPM. Also, the oxidation characteristics of the DPM are needed to understand fully this regeneration process.The rate of energy absorption P per unit volume of a sample is given byP = wE"" |Eo|2 • (1 )where w is the angular frequency, |E0|2 is the intensity of the microwave radiation, and E” is the imaginary part of the dielectric constant (E = E’ + iE”) . Thus measurements of E11 for DPM and ceramic trap material are needed to determine their capacities for microwave absorption. In this paper, we report these measurements carried out at · a frequency of 8.7 GHz. Following microwave absorption, the DPM is expected to oxidize. The oxidation characteristics of the DPM have been investigated using Fourier transform infrared (FTIR) spectroscopy of the evolved gases CO2 and CO and using thermogravimetric analysis (TGA). Finally, some information on the structure of carbon in DPM has emerged from the analysis of its x-ray diffraction spectra. Results of these experiments are reported in the following pages."

Dec 1, 1996

By H. A. Doerner

For the past three or four years attention has been attracted to the deposits of lead vanadate in the Goodsprings , Nevada , district . Some ore running as high as 9 per cent 205 has been produced , but most of it runs from 0.5 to 3 per cent . Only a little ore , and that of the richer sort , has been shipped , since the low- grade ore will not stend the cost of shipment and no concentration mill has been available . Preliminary experiments indicate that chemical treatment of the low- grade ore without concentration is not feasible . Its treatment therefore involves two distinct problems ; first , mechanical concentration ; and second , a smelting or chemical treatment to obtain the lead and vanadium in marketable form . Upon this basis the work has been conducted . The writer wishes to acknowledge the excellent work done by J. T. Norton and Virgil Miller on table concentration and by J. E. Conley , who suggested and did preliminary work on the direct smelting method . Many helpful suggestions were received from Dr. S. C. Lind and John Gross of the Bureau of Mines . The ores were furnished by Mr. Frank Williams and Mr. James Ewing .

Jan 1, 1923

By Thomas Gales

Longwall mining of thin shallow coal seams utilizing open pits is technically feasible. The thinnest coal seam which can be mined using available technology is 34 inches. The capital expenditure for a 1,000,000 ton per year operation is $15,494,000, and the projected rate of return is 5 percent. Similar statistics for a conventional area surface mine are S18,937,000 capital and 14 percent rate of return. The longwall surface mining method disturbs 63 acres of land per 1,000,000 tons, and the conventional area surface mine disturbs 198 acres A significant bibliography of the technology involved is included.

Jan 1, 1976

By S. M. Shelton

The widespread occurrence of domestic manganese deposits and the shortage of ferromanganese-grade ore have been sources of much speculation and investigative effort for many years. The present emergency has intensified the search by the Bureau of Mines for methods of producing ferromanganese-grade concentrates4/ from low-grade ores.

Jan 1, 1941

By S. M. Shelton

[The widespread occurrence of domestic manganese deposits and the shortage of ferromanganese-grade ore have been sources of much speculation and investigative effort for many years. The present emergency has intensified the search by the Bureau of Mines for methods of producing ferromanganese-grade concentrates4/ from low-grade ores.]

Jan 1, 1941