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By Lloyd A. Morley

A guide to the development and use of an APL computer program for the analysis of load-flow problems is presented. The program is designed to provide an interactive method of load-flow study to improve underground coal mine electrical system design and safety. The theoretical basis for load-flow analysis is discussed, along with per-unit calculations which facilitate computation. Specific input/output, execution and network modification procedures are presented for using the APL program. In addition, typical results are given for examples taken from power system analysis literature.

Jan 1, 1977

By T. H. Jeffers

The U.S. Bureau of Mines has developed porous beads containing immobilized biological materials such as sphagnum peat moss for extracting metal contaminants from waste waters. The beads, designated as BIO-FIX beads, have removed toxic metals from over 100 waters in laboratory tests. These waters include acid mine drainage (AMD) water from mining sites, metallurgical and chemical industry waste water, and contaminated ground water. Following the laboratory studies, cooperative field tests were conducted to evaluate the metal adsorption properties of the beads in column and low-maintenance circuits, determine bead stability in varied climatic situations, and demonstrate the beads' potential as a viable waste water treatment technique. Field results indicated that BIO-FIX beads readily adsorbed cadmium, lead, and other toxic metals from dilute waters; effluents frequently met drinking water standards and other discharge criteria. The beads exhibited excellent handling characteristics in both column and low-maintenance circuits, and continued to extract metal ions after repeated loading-elution cycles. Based on laboratory and field data, cost evaluations for using BIO-FIX technology to treat two AMD waters were prepared. Operating costs for BIO-FIX treatment, which ranged from $1.40 to $2.30 per 1,000 gal of water treated, were comparable with chemical precipitation costs.

Jan 1, 2010

By E. P. Youngman

At the time of the preparation of the monograph upon the mining legisla- tion of Newfoundland, by the Imperial Institute of London, the existing local statutory law (as distinct from case laws and the applicable English acts) con- sisted of the following legislation: 1. Chapter 129 of the consolidated statutes, entitled "Of Crown Lands, Timber, Mines and Minerals," as amended by the Crown lands act, 1928. 2. Chapters 131 and 132 of the consolidated statutes (acts relating to mines regulation and rewards for discovery of minerals, respectively). 3. Crown lands act, 1918, as amended by the crown lands (amendment) act, 1921. 4. The Labrador Act, 1927. 5. The Crown royalties act, 1927. 6. Crown lands act, 1928, together with rules and regulations issued thereunder.

Oct 1, 1932

By K. C. Dean

During investigation of the occurrence of manganese deposits in the western United States, examining engineers of the Bureau of Mines collected samples from several properties in Montana. Extensive laboratory tests were made to determine the amenability of these ores to standard ore-dressing methods of concentration to produce marketable-grade products. The Tzarena claim, one of the properties sampled, is on the western end of the Rama or Black Chief vein in the city of Butte, Silver Bow County, Mont., on the southwestern periphery of the mining district. The Black Chief 'WAR system contains one of the largest and most extensive known rhodochrosite deposits in the world. Test work was conducted on two samples of Tzarena ore. Sample 1 is representative of a vain 5 feet wide on the 150-foot level of the Tzarena shaft. Sample 2 is representative of a vein 8 feet wide in the 100-foot level of the shaft. The Minnie Jane mine, 1/2 mile northwest of the Tzarena claim, contains ore similar in mineralogical composition to Tzarena ore but differing materially in manganese content and to some extent in physical characteristics. Ore-dressing investigations were made on three samples of Minnie Jane ore. Sample 1 represented stock-piled ore, sample 2 represented ore from Minnie Jane mine having a considerable sulfide content, and sample 3 represented low-grade ore.

Jan 1, 1951

By T. A. Sullivan

The use of sulfur combined with either sand or waste copper tailings was investigated by the Bureau of Mines as a substitute for a good graded aggregate in asphalt paving materials. The research was part of a utilization program to develop meaningful uses for a projected oversupply of sulfur. Many sections of the country lack good aggregate for paving but do have available sources of sands and sulfur. The development of paving mixtures of desert sands or tailings with sulfur and asphalt was accomplished in the laboratory and tested by laying small paving test sections. Three types of material were studied for use with the sulfur and asphalt. They were (1) a concrete sand similar in gradation to river or beach sands, (2) desert blow sand, and (3) waste copper tailings. Desert blow sand and waste copper tailings are much finer than concrete sand. Mix designs were established for the three types of materials, sulfur, and asphalt used in the paving materials. The best mix designs were as follows, in weight-percent: 80.5 concrete sand, 13.5 sulfur, and 6 asphalt; and 77 either blow sand or tailings, 17 sulfur, and 6 asphalt. Small-scale testing showed that these mixtures were suitable paving materials but would require specialized equipment for transporting and laying. The chemical modification of sulfur to obtain properties that would allow placement of these materials with normal asphalt paving equipment was studied. Results indicate that reacting sulfur with dicyclopentadiene before adding it to the paving mixture was effective in modifying the sand-sulfur-asphalt paving so it could be placed and rolled with conventional equipment.

Jan 1, 1975

By David M. Hyman

The Bureau of Mines has developed two experimental designs for deter- mining the volumes and relative proportions of the various gas species, particularly methane (CH4), occluded in rock salt. To date, the rock salt samples analyzed have been relatively small (400- to 1,000-gram) grab samples from Louisiana Gulf Coast domal salt mines. The results obtained are comparable to results in Polish domal salt mines, in terms of occluded gas volumes per mass of rock salt. The notable difference between the Louisiana and Polish occluded gas mixtures is in the relative proportions of the individual gas species. The two methods used by the Bureau are ballmill crushing and dissolution. Of the two, the dissolution method appears to be more versatile because it can be performed in situ. The relevance and applicability of data on the occluded gas contents of rock salt are dependent on sample size, sample collection method, geologic context of the sample, and the correlation with gas emissions that occur as a result of mining-induced fractures and pressure differentials.

Jan 1, 1982

By D. B. Gawthrop

"In connection with the proposed use of Cordeau-Bickford to fire L.O.X. (liquid oxygen explosives) in well drill holes, the question has arisen as to the effect of very low temperatures on (1) the rate of detonation of Cordeau-Bickford; (2) the sensitiveness to detonation of its TNT filling; and (3) the lead covering of Cordeau-Bickford.The Cordeau-Bickford used in this investigation was the standard 6 mm. size, such as is regularly used in blasting, and was manufactured and furnished by the Ensign-Bickford Company, Simsbury, Conn. All pieces tested were taken from rolls, all of which were from the same melted batch of TNT in order that all the pieces tested might be as nearly identical as possible.Different portions of this Cordeau-Bickford were tested plain (not countered), countered, and double countered. The countering and double countering was carried out by the manufacturer prior to shipment.The determination of the temperature at the instant of making a test was accomplished by the use of a Leeds and Northrup potentiometer and copper constantan thermocouples. Each couple was made from No. 28 B & S gage wire with short junctions. One junction was inserted in a hole drilled by a No. 60 drill through one lead wall of the Cordeau-Bickford to approximately the opposite wall, so that this junction was in the center of the TNT filling while the other junction was immersed in ice water. The potentiometer readings in millivolts were converted to °C. from the calibration curve of the thermocouple wire,"

Jun 1, 1924

By J. E. Tiffany, Z. C. Gaugler

In presenting this list of permissible explosives and blasting devices , the Bureau of Mines desires to call attention to pages 16 and 23 , outlining the conditions in use under which , and only under which , the explosive or blasting device is permissible . In view of publications recounting trade practice favoring the use of a blasting device without stemming , particular emphasis is placed upon condition 4 on page lt and condition 2 on page 23 .. An explosive or a blasting device enumerated in the permissible lists of this Bureau is not permissible in use unless it is properly confined with clay or other incombustible stemming .

Dec 1, 1943

By Vernon F. Swanson

Several laboratory flotation tests were conducted by the Bureau of Mines on a sample of unweathered diorite from the B. F. Camden property, Amherst County, Va. Results showed that an ilmenite concentrate analyzing 45.5 percent Ti02 (titania), 0.07 percent P205 (phosphorus pentoxide), and 2.21 percent Si02 (silicon dioxide) could be produced from a feed containing 7.72 percent Ti02 and 3.94 percent P205. Ti02 recovery in the concentrate was 47.6 percent in a batch test. The weathered saprolite material overlying the diorite required scrubbing and desliming to remove argillaceous material and preliminary flotation of apatite followed by flotation of ilmenite. The resulting concentrate analyzed 47.3 percent Ti02, 0.19 percent P205, and 0.99 percent Si02 from a starting feed of 8.99 percent Ti02 and 3.37 percent P205; TiO2 recovery was 54.5 percent.

Jan 1, 1963

By Thomas A. Phillips

The Bureau of dines present, an economic evaluation of its process for the ferric chloride leaching of chalcopyrite concentrate. In this process, chalcopyrite concentrate is leached with ferric chloride solution to extract copper, which is precipitated from the solution by electrolysis while leaving sulfur in the residue. Spent liquor from electrolysis is treated with oxygen to regenerate the ferric chloride leach solution and the sulfur-laden residue is processed to recover the sulfur. A cost estimate was prepared for a plant capable of processing 600 tons of chalcopyrite concentrate per day, 330 days per year. The fixed capital cost, on an early 1.975 basis is $27,831,600 and the estimated operating cost is 9.9 cents, per pound of copper product. In comparison, the estimated operating cost of a smelter equipped with a citrate process plant to recover sulfur is about 13.6 cents per pound of copper product. No charge for chalcopyrite concentrate or credit for recovered byproducts has been included in either operating cost. The ferric chloride leach process, therefore, appears to be economically attractive.

Jan 1, 1976

By J. L. Holman

In conjunction with its research program on separation, recovery, and recycling of metal, mineral, and energy-based materials in urban refuse, the U.S. Bureau of Mines is developing means to reuse and recycle plastics discarded in raw municipal waste. Experimental work on plastic waste from a community collection has produced some guidelines for systematic methods of processing, including air classification, cleaning, separation, and use or disposal. Sink-float methods are a practical means of separation into types. Methods for final disposition of the plastic waste include refabrication, thermal decomposition, and incineration.

Jan 1, 1972

By John J. Sammarco

The functional safety of programmable electronic (PE) mining systems is an international issue and concern. From 1995 to 2001, 11 PE-related mining incidents in the U.S. were reported by the Mine Safety and Health Administration (MSHA); 71 PE-related mining incidents were reported in Australia. MSHA does not have regulations for formal evaluations of the functional safety of PE mining systems. Hence, the National Institute for Occupational Safety and Health (NIOSH), in partnership with MSHA and the industry, generated the NIOSH safety framework for functional safety of PE mining systems. An overview of the NIOSH framework is given; the key framework elements, the safety life cycle and safety integrity levels are detailed. The safety framework approach has impacted the national and Australian mining industries by enabling the industries to advance from an ad-hoc approach to a formalized and systematic functional safety process. In retrospect, valuable lessons were learned for addressing functional safety and for changing industry perspectives and practices. These lessons continue to benefit mining and are applicable to other industries as well.

By A. L. Engel

This report is a compilation of results of brief preliminary tests on sulfide ores that contained gold and silver and, in some cases base metals. It is a companion paper to a recent similar report on oxide ores. Simple treatment methods employing the least possible equipment sometimes produce satisfactory results on marginal ores and in small-scale operations. Investigations of typical ores from newly discovered or recently explored mining districts have been made in continuation of a long-established part of the hydrometallurgical and ore-dressing program of the Reno station, Bureau of Mines. The purpose of such investigations is to encourage the search for and development of mineral resources and particularly to assist in the economical exploitation of low-grade and marginal ores as well as the conservation and recovery .of values in products that were discarded from former operations because of inability to treat them profitably. Several of these investigations have been limited to preliminary tests of samples from prospecting operations, whereas same involved samples of old dumps or tailings piles. The test work in these cases was not extensive enough to warrant publication as individual reports, but is of considerable interest inasmuch as it indicates the possibilities as well as the limitations of treating the respective materials. The samples were representative of the districts from which they wore obtained, so this information should be helpful in the future development of these districts.

Jan 1, 1951

By A. L. Engel

Simple treatment methods, employing the least possible equipment, can sometimes be established for marginal ores and economical results achieved. In continuation of a long-established part of the hydrometallurgical and ore-dressing program of the Reno Station of the Bureau of Mines, typical ores from newly discovered or recently explored mining districts have been investigated. The purpose of such investigations is to encourage the search for and development of mineral resources and particularly to assist in the economical exploitation of low-grade and marginal ores, as well as the conservation and recovery of values in products from former operations that were discarded because of past inability to treat them economically. Several of these investigations have been limited to preliminary tests of samples from prospecting operations, whereas some involved samples of old dumps or tailings piles. The test, work in these cases was not extensive enough to warrant publication as individual reports, but is of considerable interest inasmuch as it indicates the possibilities as well as the limitations of treating the respective materials; and because, inasmuch as the samples were representative of the districts from which they were obtained, this in-formation should be helpful in the future development of these districts. The present report is a compilation of results of brief preliminary tests on oxide ores only, which contained gold and silver and in some cases base metals. The methods of treatment used include gravity concentration, amalgamation, flotation, and cyanidation. For the most part, only standard laboratory procedures were employed. No attempts were made to develop new methods for the low-grade refractory ores in this group of samples if simple treatment was not successful, as the stage of development of the properties did not warrant extensive experimentation on the samples submitted.

Jan 1, 1951

By William R. Roy

Seven coal-related waste samples (mining, cleaning, and gasification) were characterized chemically and mineralogically. Laboratory extracts of each sample, using a variety of different extraction methods, were used in both acute and chronic bioassays. A coal slurry sample (coarse fraction) and two coal cleaning refuse samples were chemically and mineralogically similar, and generated acidic water-waste systems, both in the laboratory and in the field. Acidic laboratory extracts and field samples of acid mine drainage in the area where the solid samples were collected, tended to be in equilibrium with some type of CaSO4 phase and with maghemite. The chemical composition of the extracts was sensitive to the method used to generate the extracts, but generally had the same prevalent chemical character as the field samples. The acidic wastes contain appreciable quantities of soluble Al, Mn, Ni, SO4, and Zn as indicated by both laboratory extraction and field data. Long-term extractions suggest that some constituents (Al, Fe, SO4) continued to be released by the acidic wastes after 22 weeks with no apparent associated change in pH. Two mine spoil samples, essentially shale, tended to generate water-waste systems that were neutral in pH and consequently released lower quantities tit potential pollutants than the acid wastes. The gasification residue was compositionally similar to coal-fired power plant slag and fly ash and generated moderately alkaline extracts with low concentration of soluble potentially toxic constituents. All of the solid wastes contained a variety of organic compounds, many of which are on the EPA Priority Pollutant List. However, these compounds were essentially insoluble in aqueous media. Each extract was tested for acute toxicity with tour species of freshwater aquatic organisms; green sunfish (Lepomis cyanellus), fathead minnow (Pimephales promelas), a crustacean (Daphnia magna), and a snail (Physa anatina). The extracts of the two mine spoil samples and of the gasification residue were not toxic to any of the organisms while the extracts from the acidic refuse and slurry samples were acutely toxic to all of the organisms. For all cases, pH was significantly correlated to mortality while Al, Fe, Mn, Ni, and Zn were significantly correlated to mortality in specific instances. Data from 96-hour LC-50 determinations showed that dilutions up to 1:1000 were necessary to eliminate mortality. The most toxic extracts were those with the lowest pH which necessitated the largest amounts of dilution to eliminate mortality. Chronic bioassays with the same test organisms were investigated with leachate samples from a relatively unweathered refuse sample and an older, more weathered refuse sample. The unweathered refuse sample generated a leachate that was acutely toxic while the leachate from the weathered refuse sample was not acutely toxic. No detrimental chronic effects were noted in organisms exposed to dilutions of the non-toxic leachate while low concentrations of the acutely toxic leachate produced lower hatchability for the Lepomis cyanellus and Pimephales promelas eggs, increased mortality with chronic exposure for Lepomis cyanellus, Daphnia, Physa, and reduced weight gain for Physa. Dilutions of a toxic, high-Fe leachate resulted in the precipitation of ferric hydroxide that was implicated as the major causative factor accounting for the physical and physiological toxic effects exhibited by all of the test organisms in these acutely sublethal concentrations. The toxicity of this leachate demonstrates the potential effects that these types of wastes can have on the aquatic ecosystem if they enter a receiving water in a natural setting.

Jan 1, 1984

By A. G. Starliper

Research was conducted by the Bureau of Mines to determine feasible roasting methods for the removal and the recovery of germanium, cadmium, and lead as enriched fractions from sphalerite concentrates. The two types of roasting processes studied were: (1) Batch, with a stationary bed, and (2) continuous, with a suspended bed, Results indicated that either method gave satisfactory metallurgical recoveries} but the continuous process is recommended because of inherent advantages. Final products were enriched fractions that could be treated by conventional methods for production of metallic germanium, cadmium, and lead. In the batch process, the concentrates were placed in a large tube furnace and heated at 1,080° C, an average of 3 hours. During the heating period, inert, reducing} or sulfur-laden gases were passed over the stationary charge to convey the sublimed metal sulfides from the hot portion of the tube to a lower temperature condensing zone at the end of the tube, where the metal sulfides were collected on baffles and recovered. In the batch and fluidizing roasting processes alike, the gases passed over or through the charge and served only as carriers for the sublimates and as suspension media in fluidization roasting. Since both processes depended on the volatilization, at relatively high vapor pressures, of the sulfides of germanium, cadmium, and lead, it was imperative that very little oxygen come in contact with the charge to alter the sulfide minerals. Germanium has a high affinity for oxygen, but in this instance it was buffered by being in solid solution in zinc sulfide.

Jan 1, 1961

By J. W. Paul

Withdrawing timber in coal mines is done for the purpose of inducing the roof to cave in the mined-out areas and thereby relieve stresses in the immediate roof material over the working places adjacent to the breakline of the roof, thus preventing the crushing of the ends of pillars and adding to the safety of those engaged in pillar extraction. A secondary purpose is the recovery of timber for further use either as prop-, crossbars, lagging, sprags or cap pieces. At some mines timber is withdrawn as a precaution against fire which may he of spontaneous origin, because wood always aids a fire of any origin. With some of the power-driven types of machines now in use a greater proportion of mine timber may be recovered, and in mines where pillars are left too narrow for their removal some of the timber in rooms might be salvaged for further use.

Jan 1, 1933

By J. F. Barkley

 This paper describes the method used and results obtained in testing a hand-fired down-draft furnace at a plant in Washington, D. C., in order to determine the method of firing that would give the best results with a minimu of smoke. The smoke regulations of the District of Columbia are very rigid, and are well enforced, A paragraph of the ordinance relating to furnaces other than household, reads, "The emission of dense or thick black or gray smoke or cinders from any smokestack or chimney 113ed in connection with any stationary engine, steam boiler, or furnace of any description within the District of Columbia shall be deemed, and is hereby declared, to be a public nuisance". This ordinance, if literally enforced, would eliminate all ordinary hand-fired grates and furnace combinations where coal other then anthracite is used. However, in several Gov- ernment plants where hand-firing of coal is still necessary conditions have been satisfactorily met by installing the down-draft type of furnace. In these plants, as at all hand-fired plants, considerable difference in operating details and methods is found. The firemen are paid day laborer's wages and are often inexperienced. The instructions of the furnace makers fre- quently do not appeal to the firemen, and are not closely followed, This is partly due to the necessity of running the boilers continuously at much higher ratings than were intended by the manufacturer. Tests were made on a Hawley furnace of this type to improve the methods of firing, particularly at the higher ratings.

May 1, 1924

[In presenting this list of permissible explosives and blasting devices, the Bureau of Mines desires to call attention to pages 17 and 23, outlining the conditions in use under which, and only under which, the explosive or blasting device is permissible. In view of publications recounting trade practice favoring the use of a blasting device without stemming, particular emphasis is placed upon condition 4 on page 17 and condition 2 on page 23. An explosive or a blasting device enumerated in the permissible lists of thin Bureau is not permissible in use unless it is properly confined with clay or other incombustible stemming.]

Jan 1, 1941

In presenting this list of permissible explosives and blasting devices, the Bureau of Mines desires to call attention to pages 17 and 23, outlining the conditions in use under which, and only under which, the explosive or blasting device is permissible. In view of publications recounting trade practice favoring the use of a blasting device without stemming, particular emphasis is placed upon condition 4 on page 17 and condition 2 on page 23. An explosive or y blasting device enumerated in the permissible Lists of thin Bureau is not permissible in use unless it is properly confined with clay or other incombustible stemming.

Jan 1, 1941