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By E. A. Hewitt

This paper describing the mining practices at the Park Utah mine in the Park City district is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. The Park Utah mine is situated at Keetly, Utah, about 5 miles east of Park City. The Park City district lies on the eastern slope of the Wasatch Mountains, 25 miles southeast of Salt Lake City. The district embraces a tract located between the crest of the main range on the west and the mountain meadows along the eastern foothills. The elevation of the Union Pacific Railroad station at Park City is 7,000 feet above sea level. The town and mines are served by two railroads; one 28 miles long is a branch of the Union Pacific Railroad and connects with the main line at Echo Junction, east of Ogden; the other is 35 miles long and joins the Denver & Rio Grande Western Railroad at Salt Lake City. The district and mines are also accessible by excellent automobile roads from Salt Lake City and surrounding points (fig. 1).

Jan 1, 1930

By X. Gumede

A model is being developed to quantify the benefits for mining houses resulting from the reduction in greenhouse gas and energy consumption by the application of innovative blast designs in addition to direct financial benefits throughout the mine to mill value chain. The conversion from shock tube initiation systems to electronics and some changes to powder factor measured on an open pit mine had previously been used to show significant improvement on blast outputs. Benefits were realised on drilling, blasting, loading, hauling and beneficiation. Quantification of the relationship between powder factor and reduced greenhouse gasses is investigated in this study. The study has highlighted new data that must be recorded and hence some assumptions were made as to fuel consumption and the energy in crushing was obtained from the Bond work equation. The mine to mill projects in an open pit platinum mine and a quarry produced energy savings and reduced greenhouse gas emissions associated with the careful application of explosives and blast innovations. The less fines project showed an increased carbon footprint. The model provides a new insight into how project feasibility should be decided based on economic and environmental viability.

Jan 1, 2012

By J. L. Johnson

The U.S. Department of the Interior, Bureau of Mines, investigated recovery of concentrates containing tin, tantalum, and niobium from the Kougarok deposit on the Seward Peninsula, AK. To date, 25 million lb of tin has been delineated in occurrences containing 0.36 to 1.32 pct Sn, and the resource potential is estimated to be as high as 25 million short tons at average grades of 0.75 pct Sn, 0.025 pct Ta, and 0,025 pct Nb. Deslimed ore was concentrated to 54 pct Sn, 0.3 pct Ta, and 0.3 pct Nb, with recoveries of 74 pct Sn and 44 pct Ta/Nb using a Humphrey's* spiral followed by a Deister shaking table. Tin values in the slimes were upgraded to a 5-pct-Sn concentrate using a Bartles-Mozley separator followed by flotation. The 5- pct-Sn was further upgraded by fuming to give a concentrate containing approximately 60 pct Sn. The recovery of the two products combined was 80 pct Sn and 46 pct Ta/Nb, A flowsheet with mill-design parameters resulted from the metallurgical testing. An economic analysis was made based on the proposed process.

Jan 1, 1990

By D. Diering

Having agreed to perform this task, I naturally started to wonder what on earth I was going to talk about, and on reviewing the literature I was surprised at how little I knew and how much I?d forgotten about the origins of this industry. For example: ?I?d forgotten that the Chinese invented black powder at least 1 000 years ago, back in the 10th century (although some say this invention occurred 2 000years ago). ?I didn?t know that Roger Bacon was the first person in the Western World to give exact directions for the making of gunpowder in 1242 and to understand its potential. Pepper?s Playbook of Metals quotes:?...above all, he is named as the discoverer of gun-powder, a material which has brought more wonderful changes in the great family of man than the most potent elixir that could have been devised to prolong life?.

Jan 1, 2000

By G. A. Pinsky, Pickard M. K

"IntroductionTWO METHODS of mucking have been used in sinking C shaft, the five-compartment production shaft of the Yellowknife property of Giant Yellowknife Gold Mines, Limited:(a) Band mucking during the original sinking in 1949 and 1950 (l); and(b) Mechanical mucking with the Cryderman shaft mucker during the recent deepening in 1954.This paper briefly describes the recent deepening and compares the performance figures of the two sinking operations.PlanningProduction planning in 1952 showed that it would be advisable to deepen C shaft in 1954 to provide for three new production levels and the installation of an underground crusher. To complete the required shaft work it would be necessary for a shaft crew to deepen the shaft about 500 feet, to partly excavate three level stations and a crusher station, and to cut a station for the loading pocket. Figure 1, a vertical section of the lower part of the shaft, shows the details of the deepening programme.During the planning period, Giant had a rather small supervisory staff and at the same time was experiencing a heavy labour turnover. As it was obvious that production would suffer if the sinking crew were recruited at the mine, it was decided that the merits of contracting-the shaft sinking to an independent contractor should be investigated."

Jan 1, 1955

By Harry Udin

IN 1948, the writer and his associates determined the surface tension of solid copper by balancing the force of surface tension in a very fine wire against an external load.' At that time we, in common with other early workers, assumed that grain boundary energy in a pure metal is very small in comparison to the energy of an external surface. Accordingly, we neglected the internal surface energy of the coarse-grained specimens. Since that time, experimental evidence has accumulated showing that grain boundary energy, far from being small, is generally about one-third of the energy of an external surface.2-4 This is sufficient to introduce a significant error into our determination. The differential equation governing equilibrium is: wdl - yds, + y*ds2 [I] rather than wdl = yds as originally written. w is the balancing force in dynes, 1 the length of the specimen, sl the external and s2, the internal surface area, y the copper/ copper vapor surface tension, and y* the grain boundary tension. Fortunately, we had made for another purpose a careful study of the size and shape of the grains, and found that the boundaries, with rare exceptions, traversed the specimens and were perpendicular to the wire axis. For this case, eq 1 leads to w = rry -(n) r2y* [2] where r is the wire radius and (n is the number of grains per unit length. A count of some twenty 5-mil wires indicated that - n became 80 & 10 after a short anneal near the melting point, and remained nearly constant for as long as 96 hr at temperature. An assumption of y* = 1/3y leads to a defining eauation for r: [31 The term in the brackets may be considered a correction factor applied to eq 11 of ref. 1. Upon applying this factor, the surface tension of solid copper at its melting point is found to be 1650 & 100 dynes per cm, rather than 1370 as previously reported.' The new temperature coefficient is —0.55 dynes per cm per "C. Grain boundary energy is more significant than surface energy to the physical metallurgist. It is evident from eq 2 that a series of experiments with wires of different grain size can lead to an evaluation of y*. The details of such an experiment are being worked out now. References 1 H. Udin, A. J. Shaler, and J. Wulff: The Surface Tension of Solid Copper. Trans. AIME, 185, 186-190; Journal of Metals (Feb. 1949) TP 25303. 2 G. L. C. Bailey and H. C. Watkins: Surface Energies in the System Solid Copper-Molten Lead. Proceedings Physical Society. (London) (1950) 36B, 350. 3 L. H. VanVlack: Inter granular Energy of Iron and Some Iron Alloys. Ph.D. Dissertation, Univ. of Chicago, Sept. 1950. 4 . P. Greenough: Grain Boundary Energies in Silver. R.A.E. Report, No. Met. 52. (May 1950) Fan-borough, Hants, England.

Jan 1, 1952

The addition of a thallous salt to the cyanide leach of a calcined pyritic concentrate causes a marked increase in the rate of extraction of gold. This is due probably to the activation of passive gold by the thallous ions. Lead, bismuth, and mercury salts, which should produce a similar effect, fail to do so. It is postulated that this latter result, together with the reprecipitation of silver at low cyanide levels, is due to the presence of soluble sulphide.INTRODUCTIONThe work of Fink and Putnam (1950) showed that the rate of solution of gold in cyanide can be increased by the addition of small amounts of lead, bismuth, mercury, and thallium salts. Mills (1951), during a study of the electrochemistry of gold, with particular reference to cyanidation, was able to show that gold may become passive towards cyanide solution. The addition of lead or thallium salts prevented this passivity, although the action of lead was limited to the pH range 10 to 12. In a recent paper Cathro (1963) confirmed the findings of Mills, and presented results which showed that the addition of thallium to a cyanide leach of a calcine from Lake View and Star mine, Kalgoorlie, increased the rate of extraction of gold appreciably. In, this paper the use of thallium to prevent the gold becoming passive, and hence to decrease leaching time and cyanide consumption, is examined.EXPERIMENTALA series of leaching tests was carried out on a sample of Lake View and Star calcine, comprising calcined pyrite (about 70 per cent.) and siliceous gangue (about 30 per cent.) and containing 165 p.p.m. gold, 45 p.p.m. silver, 0·1...

Jan 1, 1964

By J Edman, RáBeamish, G Cambourn, B Beamish

Moist Adiabatic Benchmark (MAB) and R70 testing have been applied to core samples of a multiple seam sequence from a borehole at the Doyles Creek Project. The coal samples range in rank from high volatile B bituminous to high volatile A bituminous, with a general increase in coal rank as depth increases in the borehole. The intrinsic coal reactivity to oxygen decreases with coal rank as indicated by the R70 values. The time taken to reach thermal runaway shown by the MAB testing however is strongly modified by the interaction between the intrinsic coal reactivity, the moisture content of the coal and the retained gas content of the coal. This is clearly demonstrated by the lowermost seam of the sequence. The MAB test for coal from the Whynot Seam took 20 days to go to thermal runaway, which projects to heating issues taking between eight to 12 months to occur for loosely piled coal found in coal roof falls or a longwall goaf and uncompacted stockpiles, assuming sufficient air is available for coal oxidation. The results from this project illustrate leading practice for the operational planning and development of an appropriate spontaneous combustion management plan (SCMP).CITATION:Beamish, B, Cambourn, G, Lewis, G, Edman, J and Beamish, R, 2013. Application of leading practice spontaneous combustion assessment to exploration at the Doyles Creek Project, in Proceedings The Australian Mine Ventilation Conference , pp 293-298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

By G. R. Hopkins

One of the largest items in the expense of operating a refinery is the cost of the fuel used in distillation and for miscellaneous purposes such as in the heating of buildings and in the generation of electricity, On a B. t. u. basis, the average refinery consumes approximately one-tenth as much fuel as it produces. Theoretically, the fuel consumption at refineries should be much smaller than this, but furnaces can riot be designed to be 100 per cent efficient' and, in addition, a large part of the waste heat is low-temperature heat which would not pay for the expense of recovering it. Annual surveys of fuel consumption at refineries have been made by the United States Bureau of Mines, beginning with 1925. During the 5-year period, 1925-1929, the refineries made steady progress in fuel economy. This is evidenced by the Computed figures of heat requirement Per barrel of crude oil refined, which show a decline from 829,000 B. t. u. in 1925 to 639,000 B. t. u. in 1929 (see fig. 1). In 1930, however, the trend in fuel economy was reversed and the quantity of heat utilized in refining the average barrel of crude oil rose to 672,000 B. t. u. There were undoubtedly a number of reasons for the apparent decrease in fuel economy at refineries in 1930, chief of which were the tendency to carry the distillation farther instead of merely topping the crude and a gain in the consumption of waste oils, such as acid sludge, which in actual practice yield less heat per unit consumed than has been theoretically assigned to oil. The consumption of natural as fuel at refineries has declined since 1927, but this has been more than compensated by a rapid increase in the use of refinery or still gas. The total consumption of oil as refinery fuel in 1930 was not much below the 1925 total, but the consumption of coal has declined rapidly, so that in 1930 liquid and solid fuels contributed only 56 per cent of the total heat units- utilized at refineries as compared with 77 per cent in 1925 (see fig. 2).

Jan 1, 1931

By P Moser, P Schimek, F Ouchterlony

This paper summarises the findings of 27 model-scale bench blasts in magnetic mortar, which were conducted from 2011 to 2014 at the blasting site of the Montanuniversitaet Leoben.The aim of the study was the investigation of the influence of blasthole delay times in small-scale bench blasts on the face characteristics and cracking damage created in the surrounding rock, which affects the fragmentation in subsequent rows.The test specimens or blocks, which were produced out of magnetite concrete, were roughly 1:100 in scale to normal bench blasts. The confinement of the testing blocks at the sides and back ensured the similarity to normal bench blasts with regard to the wave transmission into the surrounding rock. The specimen contained three or four rows with five blastholes each and were shot row by row, with virgin (undamaged) material in row 1 and increasingly damaged or preconditioned material in the following rows.The tested delay times varied between 0, 28, 73 and 140 µs, which corresponds to 0, 0.4, 1.0 and 2.0 ms/m of burden.The evaluation of the material properties showed that the use of magnetite concrete eliminated the inhomogeneous behaviour of rock, but some unexpected differences of the individual production cycles were still detected.The characteristics of the bench after each blast was evaluated along three horizontal lines out of a 3D model of the bench face. The tested delay time sequences of the virgin (first row) and single preconditioned blasts (second row) produced more overbreak for longer delays, while the third-row shots resulted in a smoothened surface independent of the chosen delay.The introduced damage after every blast was evaluated by an observation of irregularities on the newly blasted bench face. The visible cracks at the top of the testing blocks were documented and divided into several crack families according to their angle, length and origin. The remaining block was broken out of the blasting site after blasting, cut into several horizontal and vertical slices and dye penetrant spray was used to visualise the cracks created. Some of the detected crack families showed an influence of the delay time. The calculated mean crack density and mean crack intersection density showed that longer delays resulted in a higher degree of damage.The fragmentation results were well reproduced by the basic three-parameter Swebrec function. The observed improvement of fragmentation in the second- and third-row blasts was linked to the preconditioning of the burden for the following row while blasting the actual row. With the exception of the simultaneously initiated blastholes, the blasts showed coarser fragmentation for the shortest delays, while the longest delays generated the finest fragmentation.CITATION:Schimek, P, Ouchterlony, F and Moser, P, 2015. Influence of blasthole delay times on fragmentation as well as characteristics of and blast damage behind a remaining bench face through model-scale blasting, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 257–266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

In 1987 Wyoming became the largest coal producing state in the country. The state is known for its extensive coal resources and extremely thick coal seams. Wyoming's coal reserves total about 69.3 billion tons, or 14.2 percent of the U.S. coal reserve. Coal seams range generally from 10 to 80 feet in thickness, although one seam is 220 feet thick. The coal-bearing areas of Wyoming underlie approximately 41 percent of the state's total land area. Wyoming's coal ranges from lignite to high volatile bituminous. Most of the coal produced is subbituminous from the Powder River coal region near Gillette. The presence of coal in Wyoming was discovered before 1834 on the Belle Fourche River. The state's first mine opened in Carbon County in 1865, and with the completion of the trans- continental railroad, the demand for coal increased. Currently approximately 80 percent of Wyoming's coal production is shipped out-of-state to meet the growing demand for low- sulfur coal to fuel electric generating plants. Wyoming received conditional regulatory approval November 26, 1980. Its Abandoned Mine Land Program was approved February 14, 1983.

Jan 1, 1992

Organization Place Date 1917 American Electrochemical Society Pittsburgh, Pa. Oct. 3-6 American Institute of Mining Engineers St. Louis, MO. Oct. 8-13 American Gas Institute : Washington, D. C. Oct. 16-19 American Institute of Architects Philadelphia, Pa. _ Dec.. 26-29 American Society of Mechanical Engineers New York City. Dec. 26-29 American Mining. Congress State Chapter Phoenix, Ariz. Dec. 26-29

Jan 10, 1917

By Donald J. Olson

The North 27th St. ISS Extension tunnel will, under present plans, be the last constructed section of Milwaukee Metropolitan Sewerage District?s (MMSD?s) existing deep tunnel system. The 6.5 m (21 ft) finished diameter tunnel is approximately 3,260 m (10,590 ft) long and is located in NE Milwaukee County. When disputes over the pro-cesses to be used in owner-directed pre-excavation grouting in rock threatened the completion date stipulated between MMSD and the State of Wisconsin, the MMSD and J.F. Shea, the contractor, entered into a unique agreement. Shea accepted responsibility for all shaft and tunnel grouting and water control during the project in exchange for settlement of claims related to grout quantities and perceived delays. This significantly reduced risk for the MMSD and helped ensure the stipulated completion of the project.

By Michael S. Miller

In 1987 and 1988, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 3,100-acre Borah Peak Wilderness Study Area (10-047-004) and a 708-acre parcel adjacent to the north in order to evaluate their identified mineral resources. The study area is located in Custer County, ID, about 18 mi northwest from MacKay. The study area lies along the western foothills of the Lost River Range and is underlain by quartzite, sandstone, shale, argillite, dolostone, and limestone. The Lost River fault, a major active fault, lies along the length of the study area. Large alluvial fans spread out from valleys originating east of the study area.

Jan 1, 1989

By G Fakes

This paper describes the history of civil engineering tunnelling and developments in soft ground techniques during the 19th and 20th centuries, culminating in the design and use of high speed tunnelling machines for all types of ground conditions. Some of the problems encountered are outlined, and descriptions are given of some contemporary developments in rock tunnelling techniques, with comparisons of methods used in the mining industry.

Jan 5, 1996

By W. M. McKewan

This U.S. Bureau of Mines report discusses wire ropes used for hoisting in U.S. mines. The in-formation presented was extracted from a large body of data compiled by the U.S. Mine Safety and Health Administration (MSHA) using a data base management system (DMS). Further, these extracted data were then manipulated to provide tables of data that show the types and amount of wire rope used for hoisting. This report describes the different types of wire ropes and how a DMS can be used to manipulate MSHA's wire rope inventory data. The data indicate that more 1-1/4-in-diam ropes, 6x27 construction ropes, and right lang lay ropes are used in U.S. mines than ropes of any other diameter, construction, or lay type.

Jan 1, 1991

By Moskovits E. E

Spodumene was recovered from pegmatite by flotation in laboratory and pilot-plant tests using an anionic collector emulsion. A similar process applied to beryl pegmatite gave encouraging results.INTRODUCTIONOver the past two decades lithium and beryllium have aroused increasing interest in the metallurgical world. Both these light metals have potential uses in nuclear shielding and cooling and in lightweight alloys, and there is a growing demand for lithium chemicals for ceramics, air conditioning and lubricants. The use, technology and history of lithium has been surveyed by Schreck (1961).For many years, the only commercial production of lithium and beryllium was from pegmatite deposits amenable to hand cobbing. The most important minerals of these ores are spodumene and beryl, which are respectively lithium aluminium silicate and beryllium aluminium silicate. Norman and Gieseke (1940) investigated the treatment of lithium ores by froth flotation. The process of flotation of the pegmatite constituents away from the spodumene was applied commercially in 1951, and the operation has been described by Goter, Rainey and Hudspeth (1953). Subsequently, the flotation of the spodumene from the pegmatite was studied by Munson and Clark (1955) and Browning and McVay (1961), and this method has superceded the reverse flotation process commercially. Muskett, Tasker and Hobson (1962), in applying the method of Browning and McVay in pilot-scale tests, reported difficulty because of activation of quartz and felspar by iron salts introduced during milling of the ore.The flotation of beryl, reported by Ashton and Weir...

Jan 1, 1963

By J. M. Singer

Thermal, mechanical, and physical properties of virgin and heat-treated Pittsburgh seam coal were determined as part of a comprehensive study of combustion of monolithic coal block. The information was sought to help characterize pyrolysis and combustion processes in underground coal mine fires but should also prove useful in the study of in situ and surface coal gasifiers. Measured properties include thermal conductivity, specific heat, thermal expansion, density, compressive and tensile strength, porosity, and permeability. The transport property data were obtained (when feasible) in two mutually perpendicular directions of the anisotropic virgin coal material, and coal samples carbonized for 5 hours at temperatures of 350° C, 475° C, 500° C, 650° C, and 850° C. Other coals (Pocahontas No. 3, Sewell, and Illinois No. 6 seams) were investigated for porosity and relative permeability. Interdependence among all properties was evident from the results; however, only a few correlations could be developed owing to inhomogeneity of coal material and specimen variation, which had the effect of reducing the accuracy of measurement and increasing data scatter.

Jan 1, 1979

By H. Watari

In 1998, a voluntary agreement was reached between the European Commission and the European Car Manufacturers Association (ACEA) to reduce average carbon dioxide emissions of new cars to 25% below 1995 levels by 2008, Agreements have also been reached between the European Commission and the Japanese Automobile Manufacturers Association (JAMA) and the Korean Automobile Manufacturers Association (KAMA), However, the target average of carbon dioxide emissions of less than 140g/km in 2008 is a very challenging goal, Therefore, total product weight reduction is an objective for many manufacturers, This can be achieved utilizing materials possessing high strength and low weight, One material that has recently attracted interest is magnesium alloys, The magnesium alloys are expected to play an important role as next-generation materials, which have possibilities of contributing to lighten the total product weight when magnesium products can be used to replace aluminum and mild steel products.

Jan 1, 2005

By J. Hamilton Duffy

This is the first of, a series of papers describing dredging methods and costs in recovering sand and gravel from the beds of rivers throughout the United States and deals directly with the methods employed and costs obtained by the Ohio River Sand Co. near Louisville, Ky. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of J. R. Thoenen, mining engineer of the Bureau of Mines, in the collection of data and compilation of this report.

Jan 1, 1931