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By William G. Gruzenaky

The separation of yttrium and the individual rare-earth elements (lanthanons) from mixtures in which they occur has been a difficult problem through-out the years. Because of the increased interest in the various uses of these metals, the economy of their production may become of great importance. Studies relative to this problem, undertaken at the Federal Bureau of Mines Albany Metallurgy Research Center, resulted in the development of a solvent extraction method by which yttrium can be separated from the rare-earth metals. A separation factor of 10.93 was obtained between yttrium and cerium from a single-stage extraction, and a factor of 1.78 was obtained between yttrium and erbium from a multistage system. The valuable metals were extracted from euxenite by caustic soda fusion or by chlorination, and several separation methods were investigated. Partial separation of the yttrium and rare-earth element fraction was made by chemical methods and by solvent extraction. Thermal decomposition of aqueous rare-earth nitrates or selective ignition of yttrium and rare-earth oxalates yielded a fraction enriched in cerium. A fraction enriched in the light rare-earth elements resulted from a double sulfate precipitation, whereas a potassium ferrocyanide pr cipitation yielded a fraction enriched in yttrium. Precipitation with dimethyl phosphate yielded a fraction enriched in yttrium and heavy rare-earth elements. Enriched fractions were obtained with several solvent extraction systems. A system consisting of rare-earth nitrates, nitric acid, and tri-n-butylamine-3 methyl-2-butanone favored the separation of yttrium from the heavy as well as from the light rare-earth elements.

Jan 1, 1961

By R. V. Ramani, C. B. Manula, A. Owili-Eger

MINE PROTOTYPE The prototype chosen for application demonstration is from Kingery (1960). The mine and the ventilation plan is presented in Figure 11. A new coal mine is projected with entrance by slope 1,500 feet long. Nine train entries will be standard for development, five as intake and four as return. One return shaft is planned near the slope bottom. The slope will have an area of 150 square feet and a perimeter of 55 feet. The return shaft will be circular with a diameter of 18 feet and will be 500 feet deep. Two hundred feet of the shaft and 500 feet of the slope will be concrete lined. Will it be possible to operate five units per shift with amount of air at each unit not less than 25,000 cfm? Additionally, a shop at the slope bottom will require 10,000 cfm. The problem is completely worked out using standard ventilation formulas and simple manual calculations in the above reference and is reproduced here in Appendix II for ready reference. APPLICATION In this manual, four different applications of the PSU/MVS are outlined. An article by Stefanko et al (1972), outlines how one can move from a mine map to a network for the generation of computer input. Attention is drawn to Figure 12, which is the network line diagram of the mine ventilation system in Figure 11. Note that every roadway junction has been numbered. The dotted lines represent leakage paths and the letter 'R' on a branch denotes that the split is regulated for the quantity shown. For example, there is a leakage

Jan 1, 1975

By A. J. Rambosek

An evaluation of diamond-bit performance data accumulated from core drilling in quartzite shows that core recovery and physical characteristics of drill bits and diamonds have economic significance. Relatively inexpensive, low-quality, small Congo diamonds will perform as well as, or better than, other diamonds used as drill bart. M-type bits set with oriented Congo diamonds provide those engaged in core drilling with near optimum combination. Various factors that affect bit performance, including size of diamonds, size and type of bits, grade or quality of diamonds, and percentage of core recovered, are evaluated by means of tables, charts, and discussion.

Jan 1, 1958

By Kenneth C. Stewart

Eight brands (three samples of each kind) of commercially available audio-dosimeters were performance-tested. Each unit was placed in an anechoic chamber and subjected to various acoustic signals to measure its A-weighting response and overall integration accuracy. All units met the A-weighting tolerance for type II sould level meters, and six brands were within the Bureau I s overall accuracy requirements of ±2 dbA referred to input.

Jan 1, 1974

By W. M. Dressel

Over 2 million tons of steel furnace dust containing approximately 100,000 tons of zinc and 10,000 tons of lead are produced each year. Recycling of the dusts would conserve mineral resources, lessen land area requirements for disposal, decrease pollution problems, and aid in solving our balance of payment problem. Steelmaking dusts can be pelletized and thermally treated to remove lead and zinc and to reduce the iron oxide to form metallized pellets. In laboratory tests more than 99 pct of the zinc and 85 pct of the lead was volatilized from the dust by roasting at 1,000° C in carbon monoxide. The volatilized material can be collected and treated further for lead and zinc recovery. Reduction and volatilization of over 95 pct of the zinc and most of the lead was achieved by roasting self-reducing mixtures of steel furnace dusts and high carbon steelmaking wastes in an inert atmosphere at 1,100° C. Over 80 pct of the iron in the resulting pellets was metallized.

Jan 1, 1974

By Gordon L. Kinney

Following a year of great uncertainty, the political situation in Bangladesh improved during 1976. The major problem for Bangladesh remained the high birth rate and crowded conditions. Bangladesh had the highest population density of any agrarian country--over 80 million people in a land area of 144,000 square kilometers, 65% of which is considered arable. The Government, with considerable foreign assistance, was actively encouraging voluntary family planning, and set a growth rate target of 2% per year or less. However, even if the growth rate was reduced to the target level immediately, the population of Bangladesh would nevertheless nearly double within 20 years.

Jan 1, 1980

By Richard H. Singleton

Native asphalt was produced in 1980 by six companies in four States. Leading States were Texas and Utah. Output decreased 22% in 1980 to 1.25 million tons while value decreased 2% to $25.0 million. Bituminous limestone was produced by Whites Uvalde Mines and by Uvalde Rock Asphalt Co. in Uvalde County, Tex.; by Southern Stone Co. in Colbert, Ala.; and by Barton County Rock Asphalt Co. in Barton County, Mo. The product was used mainly in street and road repair. Gilsonite was produced by American Gilsonite Co. in Uinta County, Utah, and by Ziegler Chemical and Mineral Corp. in Weber County, Utah. This material was used for purposes other than road repair.

Jan 1, 1981

By Charles L. Kimbell

Tables 16 through 19 continue the series of providing the world merchant fleet distribution by type of vessel and the ranking of the major fleets by country of registry. Table 20 this year provides a summary of the world's liquid gas carrier fleet. These vessels are included in the totals given for the world's tanker fleet, but gives a breakdown demonstrating the growth of the importance of natural gas in the world's energy commodity consumption. Panama and Suez Canals Tables 21 and 22 provide the latest available information on the transit of mineral commodities through the Panama Canal, by number of vessels, direction, and the commodities transported. Although the number of vessels transiting the Panama Canal dropped slightly (0.5%) between 1989 and 1990, the total amount of cargo moved rose by 3.6% and the amount of mineral commodities moved rose by 7.2%.

Jan 1, 1993

By Kelly C. Strebig

Laboratory tests were conducted by the Bureau of Mines to determine the effect of depth of cut and bit type on respirable coal dust generation. Apparatuses were constructed to contain the coal samples, measure the linear cutting forces, and analyze the dust generated. Single-bit tests were conducted in Illinois No. 5 and Pittsburgh seam coals with five bit types at four depths of cut. The results showed that bit type did not significantly influence dust production. On the other hand, deep-cutting bits were more efficient and generated substantially less respirable dust per pound of coal broke than shallow-cutting bits.

Jan 1, 1975

By N. A. Caspero, W. E. Eckard, W. T. Wertman

A thermal oil-recovery experiment was conducted in the Venango First sand, Goodwill Hill oilfield, Warren County, Pa., about 10 miles northeast of Titusville. The Quaker State Oil Refining Corp., Bradford, Pa., performed the experiment with assistance from Sinclair Research, Inc., Tulsa, Okla., and the Federal Bureau of Mines. The Goodwill Hill field was discovered in 1885. Primary-production oper- ations continued until 1930 when an air-gas injection project, which is still in operation, was started. At the location of the combustion experiment, the reservoir is 400 feet deep and 30 feet thick, with wide permeability and porosity variations. The crude oil is typical Pennsylvania Grade paraffin- base oil with a gravity of 43.9° API and a viscosity of 4.55 cp at 60° F. The well pattern for the experiment consisted of 5 producing wells, enclosing an area of 1.28 acres, and a central ignition-injection well. An air-natural gas mixture was ignited in the ignition well on July 29, 1961. Ignition was followed by injection of air and natural gas at various rates. The experiment was suspended January 5, 1962, when it became evident that economic oil production could not be achieved. There was no conclusive evidence that self-sustained combustion was achieved or that combustion increased oil and water production. A slight increase in liquid production was attributed to stripping action caused by the air-injection rates, which were higher than those normally used during air-gas injection.

Dec 1, 1963

By W. M. Merritts, Charles Findlay, Stephen Krickovic

Methane emission rates were studied in a Pittsburgh coalbed mine in northern West Virginia. A fullface boring-type continuous miner, equipped with a methane monitor, was used in the development of a set of eight main headings, one side of which was near old workings; the other side abutted virgin coal. Two air splits ventilated the section. Air volumes and methane percentages were recorded, and time studies of the miner were made during five consecutive operating days, during which a complete cycle of mining the headings and one line of related breakthroughs was accomplished. Methane emission rates increased significantly as mining progressed from the side near old mine workings toward the virgin area, and generally increased with coal extract ion. Mining in the heading immediately adjacent to virgin coal was interrupted quite frequently, owing to excessive methane concentrations at the face, despite adequate air volumes and acceptable methane concentrations in the immediate return airway.

Aug 1, 1970

By Carlton E. Brown, William P. Yant

"INTRODUCTION Direct visual microscopic determination of particle-size distribution and number concentration of atmospheric dust is time-consuming and trying to the eyes. By using the microscope to project images of the particles at high magnification onto a screen much of the eyestrain can be eliminated and particle-size distribution results obtained with less effort and at a considerable saving in time. It also permits simultaneous observation of the images by more than one person. Microprojection requires no more skill and very little more apparatus than is required in the use of the microscope. Anyone familiar with the microscope should be able to obtain as perfect images on the projection screen as in direct visual microscopy since the same laws and limitationsThe theory and practice of microprojection are described in detail in texts. 5/6/ The procedure has been used and found to be satisfactory for measuring the particle-size distribution of sub-sieve-size substances, such as pigments and powder 7/8/ in the same size range as that of atmospheric dust. The Bureau of Mines has used the microprojector and found it to be quite satisfactory for (1) the determination of the number concentration of atmospheric dust R.I. 3289 in samples collected by the Owens jet dust counter; (2) particle-size distribution in samples of atmospheric dust collected by the Owens jet dust counter and by the electric precipitator; and (3) the particle-size distribution of dusts, blood cells, bacteria, and pollen. Work is in progress at this Bureau on the use of the microprojector in counting impinger samples. The use of different kinds of illumination, such as reflected (dark field), polarized, monochromatic, and ultraviolet, in the projection of images of atmospheric dust particles is being considered."

Oct 1, 1935

By Charles D. Martens

Raw non fuel minerals produced in the United States during 1981 had an estimated value of $25 billion, about the same as that of 1980. In terms of 1980 dollars. the value of minerals produced during 1981 was $23 billion.2 This chapter includes tables for 1980 that were not available for publication in the 1980 Minerals Yearbook, but does not include the corresponding tables for 1981. The underlying causes of the overall decline in U.S. nonfuel mine production during 1981 were varied, but the common factor was the worldwide recession. In some cases the decline was traced to foreign competition. For example, iron ore production was lower in part because of increased imports of steel products such as coiled steel sheet. Another problem experienced by the domestic mining industry was the continuing difficulty in attracting capital. This was due in part to the attractiveness of investments outside the mining industry, such as short-term, high-interest securities. Another reason was the importation of commodities from countries where overall costs were lower because of such factors as high ore grade, lower taxes, lower wages, government subsidies, and less stringent safety and environmental regulations.

Jan 1, 1982

By Edward D. Thimons, Jay F. Colinet

NIOSH conducted a strategic planning effort to identify those areas in mining with the greatest research needs. Data analysis and stakeholder input identified the need to reduce worker exposure to respirable crystalline silica dust as a high priority area. MSHA dust sampling data were analyzed to target the mining commodities and occupations with the greatest percentage of samples containing silica above compliance levels. In response, the Pittsburgh Research Laboratory (PRL) has implemented a multi-faceted research program to improve silica dust control for these problematic commodities and occupations. A review of silica compliance trends, PRL silica research programs, and recent control technology developments are provided here.

By C. C. Shale

A semicommercia1, high-temperature electrostatic precipitator and adjunct equipment are described, and operating characteristics at 1,470° F and 80 psig are presented for both positive and negative polarity. Removal efficiency for negative corona waS about 91 to 96 percent while that for positive corona was only about 75 to 77 percent. Results are compared with those from bench-scale investigations, and equipment limitations are discussed. Theoretical aspects of the precipitation process are related to the operating characteristics.

Jan 1, 1969

By Richard E. Dawes

Physical variables, a principal factor in the economies of mineral production, affect both capital and direct operating costs. By using a revenue-cost system for the framework, the analyses of revenue and cost categories demonstrate the relative importance of groups of physical variables, whether explicitly defined or not, to a lead-zinc mining operation. Physical variables affecting the producer represent about 60 percent of the total system influence as expressed by cost ranking. Other physical variables affect the remaining costs as controlled by the smelter, the transporter, and the landowner. Such resource conservation aspects as mineral losses due to mining method and mineral processing constitute a portion of the total revenue effects of physical variables. The physical variable revenue-cost system presented in this report offers a framework for cost-benefit analysis of mineral related research.

Jan 1, 1969

By Robert P. Vinson

This report describes three coal mine ventilation studies by the Bureau of Mines in which sulfur hexafluoride (SF6) was used as a tracer gas. One of these studies was conducted to determine air movement and leakage in a sealed area. Another was run to determine the ventilation efficiency of a bleeder system. Finally, a study was made of air leakage across permanent stoppings of parallel intake airways. These studies proved sulfur hexafluoride to be a useful addition to the equipment commonly used in coal mine ventilation analysis.

Jan 1, 1976

By F. L. Wideman

Materials handled at metal and non-metal mines in the United States increased 10 percent compared with those of 1965 as a result of expansions in output at existing mines and development of others to meet increasing demands for mineral products. The tonnage of commercial materials mined or quarried increased as did the quantity of waste handled. Crude material from which metal or nonmetal products were derived comprised 71 percent (75 percent in 1964) of the total materials handled. Great strides were made in mining technology and there were indications that, in the future, earth moving by the mining industry will involve materials-handling systems of increasing size and complexity. Materials Handled.-Output of ore and waste at metal and nonmetal mines and quarries in the United States in 1966 totaled 3,518 million tons (3.213 million tons in 1965). The quantity of materials handled has increased at an average annual rate of 5 percent since 1962. Ore production increased 4 percent over that of 1965, also comparable to the average annual rate of increase in the last 5 years. Waste removal in 1966 increased 25 percent over that of the previous year.

Jan 1, 1967

By Oliver Bowles

"A New Mica Company in China A report has been received from the American Consulate at Chungking, China, to the affect that a new company has been organized to operate a mica mine north of Ta-chien-lu, in the province of Ssu-Chuan. The company, which is entirely under Chinese management and control, has a working capital of $10,000. While comparatively new, the mine has been worked before, and apparently with some success. The mica is said to be of good quality. It is claimed that the deposit will supply a limited amount of mica that will cut in pieces a foot square or over, and larger quantities of smaller sizes. The chief difficulty is transportation, for it is reported that a ten days' journey, part of it over mountain trails, will be necessary to transport the mica from the mine to Yachow, the nearest practical waterway. It is probable, therefore, that the output of the mine will be limited.Necessity for Careful Trimming and Grading of MicaA recent report to the Department of Trade and Commerce, Ottawa, Canada, by Acting Trade Commissioner C. G. Venus, London, England, contains information which is of vital interest to mica producers in the United States. It is pointed out that mica exports from Canada to England show a gradual decline dur¬ing recent years, the figures being as follows: 1913- 1,383 cwt: 1914 - 1,225 cwt: 1915 - 1,864 cwt: 1S16 - 879 cwt: 1917 444 cwt: 1918 - 480 cwt. Shipments from India to England, on the other hand, show a steady increase from 40,178 cwt. in 1913 to 66,401 cwt, in 1918."

Jan 1, 1920

By Gerrit V. R. Goodman, Fred N. Kissell, Charles D. Taylor

In This Chapter [Methane emission peaks Exhaust line curtain or duct The spray fan system Dust scrubbers with blowing ventilation Dust scrubbers with exhaust ventilation The ventilation of abnormally gassy faces Methane detection at continuous miner faces Ventilation and methane detection at bolter faces and Reducing frictional ignitions] This chapter gives guidelines for preventing methane gas explosions at continuous miner sections in coal mines, both at continuous miners and at roof bolters. The need to control peak methane emissions is particularly stressed. Emphasis is also placed on ventilation principles, monitoring for gas, and reducing frictional ignitions. METHANE EMISSION PEAKS Methane emission from the coal at continuous miner faces varies considerably. Plotted on a chart, methane emissions consist of a series of peaks and valleys corresponding to the cutting cycle of the mining machine, with the methane concentration spiking as the machine cuts into the coal (Figure 3–1) [Kissell et al. 1974]. These methane peaks can be substantial. For this reason, efforts to safely dilute the methane must focus on the level of the [ ]

Jan 6, 2006