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By King E. J

Department of Pathology, British Post-graduate Medical School, London:The experiments here recorded were devised and carried -out during the last two years in an attempt to corroborate the important work of Denny, Robson and Irwin (1939) in which they found that experimental silicosis could be prevented by means of metallic aluminum. By causing rabbits to inhale powdered quartz for several months they induced experimental silicosis. These animals then served as controls for comparison with another group which were dusted with a mixture of quartz and aluminum. In the second group silicosis failed to develop.Our experimental procedure was somewhat different. We resorted to intratracheal insufflation instead of simple inhalation, and we used rats instead of rabbits: otherwise the essential features of the original experiments were carefully duplicated.EXPERIMENTAL PROCEDURES.A single dose of dust was delivered into the lungs of each animal. The dust was suspended in a fluid medium and injected by means of a syringe directly into the trachea in known quantity (technique of Kettle and Hilton, 1932). The suspensions were autoclaved before use and were injected with aseptic precautions. Having had a long experience of this technique we employed it with confidence and usually secured a fairly uniform dispersal of dust throughout both lungs. To carry out injections successfully one requires, above all, an even suspension of dust which will flow smoothly and quickly from the syringe. This is not difficult in the case of quartz, for, though it tends to settle out rather quickly, this can be avoided by constantly agitating the suspension. The syringe containing the inoculum may be shaken gently right up to the moment of injection and then emptied quickly to prevent sedimentation. Powdered aluminum is more difficult to handle, for the particles tend to flocculate and are not readily made to disperse evenly in saline, even by violent shaking. For this reason an emulsifying agent may be used to advantage, provided it does not complicate the experiment, a point to be mentioned again presently.THE EXPERIMENTSExperiments with quartz alone: Extensive silicotic lesions were produced in 23 out of 26 rats by the administration of pure quartz dust in doses of from 50 to 200 mg. per rat. The dust was so finely pulverised that the particles averaged about 1-p. in size: none was larger than 5 p. and 99 per cent. were under 2.5 p.Eight of these animals survived for seven months and were then killed...

Jan 1, 1945

By Joshua Hoffman, Braden Lusk, Kyle Perry

This study explores how different geometries affect the shock tunnel’s performance and is broken down into three phases. Phase 1: Open arena testing in which theoretical energies produced by the detonation of small (<1.0 kg) charges are compared to actual experimental values. Phase 2: Shock Tunnel testing in which realized energies are experimentally recorded for the UK and S&T shock tunnels. Phase 3: Analysis of the data to begin building a pressure-forecasting tool for the UK shock tunnel given the explosive characteristics, sample size and desired pressure and impulse.

Jan 1, 2009

By Lucien Eaton

THE use of filling in mines is less common in the United States than it is in Europe, where in some places it is required by law. In most cases the filling is placed by hand, and the material used for this purpose is the waste from development and that sorted from the ore in the stopes. When these sources provide an insufficient supply, additional rock must be quarried on surface or mined underground, or some other material :st be used. In different parts of the world sand, clay, gravel, culm, nulated slag, mill tailings, and even ashes, have been used as filling material in place of or in conjunction with rock. Of all the materials used for filling the best is probably clean sand. Gravel, finely crushed rock, granulated slag and coarse mill tailings are almost as good, and the methods used for placing and confining sand will apply equally well to any of these. The advantages of sand are its comparatively slight compressibility and the ease, economy and convenience with which it may be placed. On account of the voids, which necessarily occur in fills made of coarse waste, such fills will compress 10 to 25 per cent before they develop their full strength, whereas clean sand seldom compresses more than 5 per cent. Sand is especially desirable when practically complete filling is required, and sand derived from mill tailings, especially when not thoroughly cleaned, has been remarkably effective in sealing off and extinguishing mine fires. When natural sand is available on surface, or when it can be obtained from the mill tailings or tailings dump, the cost of using this material for fill will probably be considerably less than that of rock. In this paper it is not proposed to discuss all methods of filling, butt to describe some of the methods used for placing sand fill and to make a brief comparison of their merits.

Jan 1, 1932

By Steven R. Munts

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied 8,445 acres of the 20,650-acre Tunnison Mountain Wilderness Study Area in order to evaluate its identified mi nerd 1 resources. The study area is located in Lassen County, CA, about 8 miles northeast from Susanville. No mineral resources were identified in the study area based on literature, field observations, and sample results. No mines were operating in or near the study area in 1985, and no mines, prospects, or claims have been located in or within 1 mi le of the study area. The study area is underlain by Pliocene and Pleistocene volcanic units composed of basalt, andesite, rhyolite, and some pyroclastics. No metallic and only nonmetallic commodities are present in the study area. These included stone and sand and gravel. Although substantial volumes of basalt and andesite (stone) occur within the study area, no identified resources of these commodities were delineated. Sand and gravel is not economic because of small occurrence size and lack of local markets.

Jan 1, 1987

Minerals are vital to any industrialized civilization. Annually, the United States uses more than 4 billion tons of new mineral materials, or about 40,000 pounds per person-about half being mineral fuels and the other half being metals and nonmetallics. Stable and economic domestic mining, mineral, metal, and mineral reclamation industries are essential to the economy. The value of United States energy and processed materials of mineral origin exceeds $200 billion annually. Although a number of minerals are imported, especially some designated as "strategic and critical," most U.S. mineral supplies are derived from the domestic mines and processing facilities that you will be seeing, reading about, and visiting as you use this visitor guide. We hope you enjoy your experiences. This pamphlet, a guide to mining and mineral operations that may be observed or visited and some other points of interest relating to minerals, is intended to aid tourists and students who are interested in mining. Some may wish to study our Nation&apos;s romantic past; others may plan to enter the minerals industry as a career; still others may have a primary interest in conservation practices. The pamphlet is also intended to aid State and local officials, Chambers of Commerce, and mining firms in answering some of the many questions of tourists and students.

Jan 1, 1976

By M. A. Kujoana

Following on the design of good mining layouts and regional support systems, and the implementation of sound strata control practices, stope support is the ultimate strategy to combat the hazards of rockfalls and rockbursts. The primary function of stope support in intermediate and deep level mines is to stabilize the rock mass immediately surrounding stoping excavations, that is, the zone of fractured rock which behaves in elastically around stopes. Support design is a process resulting in a support system which is both practical and meets or exceeds by a factor of safety the requirements for a particular geotechnical environment. The aim of this project was to design a support system, which accommodates the factors of rockfalls and rockbursts. The pack support unit must be easily handled, less costly and can be used in stopes without any significant convergence. The project tested the structural stability of packs to their expected deformation, in order to design a height to width ratio for stopes where little convergence is expected.

Jan 1, 2009

By G. S. Hume

Production of petroleum and natural .gas increased in Canada in 1940 over the previous year. Alberta produced more than 97 per cent of the total Canadian production of 8,718,053 bbl. of oil, an increase for this province of nearly 12 per cent, whereas in Ontario and New Brunswick, where the production is relatively small, there was a slight decline. In Alberta the main producing field is Turner Valley, on the eastern edge of the foothills southwest of Calgary, and development continued in this field in 1940 with the completion of 36 wells, all of which obtained production. In the Red Coulce field, close to the International Boundary, near Coutts, no new wells were drilled and the seven producing wells showed a decline of 900 bbl. below the previous year. Also, in the Wainwright field of east central Alberta, four wells, yielding heavy crude oil, produced 4000 bbl. less oil than in 1939, owing possibly rather to discontinuous operation than to actual decline in potential yield. This decline was more than offset by production from a new field 40 miles northeast of Wainwright, at Borradaile, producing oil of 14" to I 5° A.P.1. There was a small increase in production during 1940 from the Del Bonita field, in southern Alberta, where the production is from two wells. The outstanding development of the year was the completion of Standard Oil Princess No. 2 well in the Steveville area, on the Plains 100 miles east of Calgary. This well was completed late in December with an initial flow1 of 520 bbl. of 26.3" A.P,I. oil, and 12,750 M cu. ft. of gas from the upper part of the Mississippian limestone. It has opened up a new field and given a further proof of the potentialities of the Southern Plains. The production of petroleum in Canada is shown in Table I. Since most of the yield comes from Alberta, the production is shown from the various fields in Table 2. The sale value of the petroleum produced in Canada in 1940 exceeded 11.1 million dollars, which is still somewhat less than the value of the natural gas production, shown in Table 3. Table i.—Production of Petroleum in Canada" Barrels Province 1939 1940 New Brunswick........ 20,101 21,161 Ontario............... 206,196 186,471 Alberta............... 7,595,000 8,493,237 Northwest Territories. . 17,013 8,493,23717.184 Total............... 7,838,310 8,718,053 Value............... $10,353,351 $11.113,000 0 Bureau of Statistics, Ottawa. Turner Valley, Alberta Turner Valley continues to be by far the largest producing field in Canada (details are given in Table 4), The limits of the Pr in- field are now Known. On the east the oil area is bounded by the gas cap, which in turn is cut off on its east side by a major overthrust fault; on the west, ii is defined by edge water at a level of 4roc

Jan 1, 1941

By G. S. Hume

Production of petroleum and natural .gas increased in Canada in 1940 over the previous year. Alberta produced more than 97 per cent of the total Canadian production of 8,718,053 bbl. of oil, an increase for this province of nearly 12 per cent, whereas in Ontario and New Brunswick, where the production is relatively small, there was a slight decline. In Alberta the main producing field is Turner Valley, on the eastern edge of the foothills southwest of Calgary, and development continued in this field in 1940 with the completion of 36 wells, all of which obtained production. In the Red Coulce field, close to the International Boundary, near Coutts, no new wells were drilled and the seven producing wells showed a decline of 900 bbl. below the previous year. Also, in the Wainwright field of east central Alberta, four wells, yielding heavy crude oil, produced 4000 bbl. less oil than in 1939, owing possibly rather to discontinuous operation than to actual decline in potential yield. This decline was more than offset by production from a new field 40 miles northeast of Wainwright, at Borradaile, producing oil of 14" to I 5° A.P.1. There was a small increase in production during 1940 from the Del Bonita field, in southern Alberta, where the production is from two wells. The outstanding development of the year was the completion of Standard Oil Princess No. 2 well in the Steveville area, on the Plains 100 miles east of Calgary. This well was completed late in December with an initial flow1 of 520 bbl. of 26.3" A.P,I. oil, and 12,750 M cu. ft. of gas from the upper part of the Mississippian limestone. It has opened up a new field and given a further proof of the potentialities of the Southern Plains. The production of petroleum in Canada is shown in Table I. Since most of the yield comes from Alberta, the production is shown from the various fields in Table 2. The sale value of the petroleum produced in Canada in 1940 exceeded 11.1 million dollars, which is still somewhat less than the value of the natural gas production, shown in Table 3. Table i.—Production of Petroleum in Canada" Barrels Province 1939 1940 New Brunswick........ 20,101 21,161 Ontario............... 206,196 186,471 Alberta............... 7,595,000 8,493,237 Northwest Territories. . 17,013 8,493,23717.184 Total............... 7,838,310 8,718,053 Value............... $10,353,351 $11.113,000 0 Bureau of Statistics, Ottawa. Turner Valley, Alberta Turner Valley continues to be by far the largest producing field in Canada (details are given in Table 4), The limits of the Pr in- field are now Known. On the east the oil area is bounded by the gas cap, which in turn is cut off on its east side by a major overthrust fault; on the west, ii is defined by edge water at a level of 4roc

Jan 1, 1941

By Andrew Pontecorvo

The design of foundations for the tall buildings of lower Manhattan rely on the use of high capacity, rock anchors to resist overturning forces generated by lateral loads from wind, earth, water and, to a lesser degree, seismic forces. Once completed, the proposed towers at the World Trade Center (WTC) site will be among the tallest buildings in New York City. The towers are exposed to coastal winds and from several levels of below grade structure soil and water loads. The design loading required under the current New York City Building Code (NYCBC) is similar to the requirements of the building code used to design the original WTC Twin Towers. We will compare how rock anchors were deployed in the Twin Towers and how they are used in the new buildings. Changes to the building code are less significant that the changes to the design of the structure; that is how the outer skin or perimeter structure interacts with the building core. The result is a significant increase in the number of rock anchors required for the new buildings when compared to those installed in the original WTC Twin Towers.

Jan 1, 2011

Inn mining communities throughout the western United States, cows have always been part of the landscape as they graze on surrounding rangelands. Until recently, mining companies regarded these animals as something to be kept off their properties — especially any freshly reclaimed lands. During the last few years, though, this situation has begun to change. Today, cattle can be seen in a handful of mine settings, moving up and down the slopes of mine tailings and waste rock. These animals are being used by several companies to do some of the reclamation work once performed by large earth-moving equipment, mechanical spreaders, rippers and seed drillers. This is because cows can contour slopes more naturally and produce and spread soil nutrients in ways that tractors and ripping machines cannot.

Jan 1, 1999

By L. A. Matthews

The embrittlement of the Ti-6Al-4V alloy by hydrogen dosing at elevated temperature has been investigated. Metal coupons were subjected to isothermal treatments in a partial hydrogen atmosphere in the temperature range from 650ºC?950ºC and the degree of embrittlement after treatment was determined by drop-weight impact testing. Embrittlement was found to be inversely related to reaction temperature as a result of the combined effects of greater hydrogen absorption and titanium hydride precipitation at the lower isothermal temperatures. Keywords Titanium, hydrogen embrittlement, impact energy

Jan 1, 2011

By John J. Henn

An economic evaluation was made of the Bureau of Mines incinerator residue separation process to update the one published in 1971 to a mid-1.974 cost basis. This evaluation includes a modification of the glass-recovery operation used In the original plant design as well as a unit to bale the ferrous scrap product before shipment. Products from the plant are ferrous metal, aluminum and copper-zinc scrap, and a mixed-color glass cullet. The estimated capital and operating costs for four plant sizes are as follows : [ ] The operating costs do not include credits for recovered metals and glass.

Jan 1, 1975

By Gregg Hodges, Fred Schoenbrunn, Steve Slottee, Chad McCleary

"In December, 1999 Stillwater Mining Company (SMC) commissioned a new paste /cement backfill plant to supplement the existing sand backfill system for the cut and fill mining operation at it’s Nye, Montana mine. The new plant uses the Baker Process Deep Cone TM Paste Thickener to thicken the total concentrator tailings from 30% solids slurry to a 71% solids paste. This paper describes both general paste formation concepts and the evolution of the SMC paste plant operation from original design criteria, through problem solving and plant modifications, to the operation of the existing plant.Although the original process design was not effective for consistently producing and delivering acceptable paste to the stopes for backfill, SMC was able to make the mechanical and process modifications which allow the plant to now produce and deliver an acceptable product to the stopes. Ongoing test work is targeted at increasing the pumping range of the system, increasing the paste solids concentration from the Deep Cone Paste Thickener and reducing the operating and maintenance costs of the system.INTRODUCTIONThe authors would like to thank both Stillwater Mining Company (SMC) and Baker Process for their assistance in the preparation of this paper. Stillwater Mining Company chose not to participate directly in this paper due to time constraints, but was very helpful in answering questions concerning their approach to problem solving and specific details with regard to engineering criteria.This paper will begin with a general review of the technical and mechanical concepts in paste formation and then focus on the overall design, start-up and problem solving process for the paste backfill operation at SMC’s mine and concentrator near Nye, Montana."

Jan 1, 2001

By Brent Blanchard

As most veterans of our industry are aware, explosive demolition by its very nature is often a challenging proposition. Even under the best of circumstances, proper planning and care must be taken during a variety of processes to ensure a safe, successful result. However, every now and then a project suddenly arises where safety, timing and cost factors combine to form a critical scenario requiring rapid execution in an environment far more challenging than the norm. On these occasions, the stresses, complications - and most notably the dangers - related to the industry increase exponentially, and conspire to test the mettle of even the most seasoned experts.

Jan 1, 2003

By Paul E. Melancon, Vincent C. Kelley, Dale F. Kittel

Uranium of the Grants region occurs predominantly in continental sandstones of the upper part of the Jurassic Morrison Formation, but significant lesser deposits are found in limestone of the Jurassic Todilto Formation and in black shale of the Cretaceous Dakota Formation. The deposits are disseminations that form runs ranging from a few hundred tons to several million tons. The ore consists mainly of uraninite, uraniferous carbonaceous material, coffinite, and such secondary oxidized minerals at tyuyamunite, carnotite, and uranophane. In sandstone, the ore runs were locallized by mudstone, interstitial carbonaceous material, and primary sand channel trends. In limestone, ore deposition was related to folds and fracture zones. The great bulk of production has come from the Ambrosia Lake mines in the Grants district and the Jackpile and Paguate mines in the Laguna district. The ores, which generally have been 0.20 to 0.30 per cent U3O8, are treated at mills operated by Kerr-McGee Corporation, Homestake-Sapin Partners, and The Anaconda Company, all in the Grants district. In 14·years after discovery in 1950, the deposits had yielded concentrates valued in excess of $800,000,000. Since deposition of the Jurassic host rocks, a geologic history involving tilting, faulting, erosion, changing ground-water environments, and oxidation has considerably influenced the existence and character of the deposits. It is evident that their ongm is not simple. However, a degree of agreement appears probable for a pre-Dakota age for the original ore runs, and, at Ambrosia Lake, two principal stages of ore formation, separated by Laramide faulting, are recognized. All earlier ores have been modified by Quaternary oxidation, solution, and enrichment during which time much secondary tyuyamunite, metatyuyamunite, carnotite were formed.

Jan 1, 1968

By D. Knuutila, G. Goyette, James A. Finch, G. Bartolacci, A. Fortin, Chi Ho Lau, A. Lockhart

"In a COREM-McGill collaborative research and development project, gas dispersion parameters and froth properties were manipulated in a copper flotation plant to study interactions between the collection and the cleaning zones. In this paper, specific work on developing some relationships between operating conditions and froth stability in a rougher column flotation cell of 125 m3 is reported. Froth stability, measured by image analysis, was related to the following process conditions for specific flotation machines in an industrial case study: Gas flow rate, collector dosage, pH, frother type and dosage. Across the range examined, froth stability was improved through a decrease in gas flow rate and/or increasing frother dosage. Metallurgical results (grade and recovery) showed that both gold and copper were dependent on froth stability.INTRODUCTIONMcGill and COREM have over the past two years collaborated in a research and development project to merge gas dispersion parameters, frother analysis (McGill technology), and froth properties (COREM’s imaging system) to study the interactions between the collection zone (pulp) and the cleaning zone (froth). The main goal is to increase knowledge of flotation cell hydrodynamics since it is known to govern the metallurgical performance of the flotation process (Power et al., 2000). In this paper, specific work on developing some relationships between operating conditions and froth stability in a copper flotation circuit is reported.The objective of this work is to study gas dispersion in a large volume flotation column (hydrodynamics) and to measure its impact on the froth. By froth imaging, it is possible to diagnose operational problems on the basis of froth characteristics (Bartolacci et al., 2005a) and consequently, to propose ways of improving process performance by froth analysis (Bartolacci et al., 2005b).Another approach to froth characterization is investigated in this paper. In the same flotation column, a froth stability apparatus (column) was included (Triffet and Cillers, 2004). The mechanical froth stability apparatus is used to link “hard” froth characteristic measurements to “soft” froth characteristic measurements (those obtained by imaging)."

Jan 1, 2008

By Rogerio de Oliveira Baldoino

The sedimentary phosphate deposit of Bayovar is located in a very dry area of Peru (desert of Sechura) which is close to the Pacific coast. It consists of seven superposed layers (beds) which call for different strategy of concentration. The ore is composed predominantly by apatite (84% in weight basis) plus silicates (16%). In order to treat the ore from beds 1-5, a suitable standard mineral processing circuit (composed of scrubbing, screening, attrition and desliming) started its operation in 2010, yielding 3.9 Mt/y of concentrate assaying 30% of P2O5. To concentrate phosphate from beds 6-7, however, it is necessary to carry out further cationic reverse flotation of silicates, at neutral pH, to yield a concentrate, which meets market specification. The new process was developed in laboratory scale by a collaborative program conducted between Vale S.A. and the University of Sao Paulo-Brazil. A pilot plant has currently been running in order to confirm the very good results yielded in laboratory scale. The successful accomplishment of flotation in the current beneficiation flow sheet will enable a capacity expansion of 1.9 Mt/y of concentrate assaying 30% of P2O5. As water resources are very limited at Bayovar region, all the steps of concentration, including flotation, must be performed with seawater, which must be continuously recycled. This work addresses some relevant topics related to the use of seawater in the reverse cationic flotation of silicates: influence of temperature, water quality (ageing and chemical composition) and collector type (ether amine versus condensate). The results indicate that condensate amine works better than ether amine. If flotation is conducted with the former collector, the separation process is able to tolerate changes in temperature (25-40oC) and water quality caused by either evaporation or ageing. Keywords: phosphate, flotation, seawater, temperature, ageing, concentration, salt

Sep 1, 2012

By S. Hamm

Elevated total dissolved solids (TDS) content in waters downstream from surface coal mines in Central Appalachia is an increasing concern, as unnaturally high TDS and/or associated specific conductivity (SC) may contribute to deteriorated stream ecosystem health. The aim of this preliminary study was to explore the efficacy of accelerated leaching as a means of minimizing long-term TDS/SC generation by problematic overburden materials. Five spoil samples were collected and leached using simulated rainwater solutions under ambient and acidified pH conditions. SC and pH were monitored during each leach cycle, and ICP-MS was used to determine how leaching conditions affected release of specific ions. This paper highlights the results of both jar and column leaching tests. Among the most significant findings was that, for certain spoil materials, SC in leach column effluent was effectively reduced when spoil was leached first with acidic rainwater followed by ambient rainwater (vs. ambient rainwater leaching alone). This suggests that accelerated leaching might aid in long-term stabilization of some materials.

Feb 23, 2014

By Michael W. Redifer

A Fortran IV computer program was developed to calculate the composition at equilibrium of products from a set of high-temperature gas combustion reactions. The program was used to develop high-temperature equilibrium concentration profiles for various constituents as a function of temperature and oxygen concentration. The computer program was specifically applied to reactions pertaining to the corrosion of superheater tubes in pulverized coal-fired boilers; however, it is useful for any multicomponent, multireaction scheme in which equilibrium constant data can be obtained and is comprised of gaseous reactants along with finely dispersed solids or liquids. General applicability of the computer program, including its limitations, are discussed along with detailed instructions for using the program.

Jan 1, 1973

By D. Earley

High metal prices and new world trade standards and accounting for environmental liability in financial disclosures are creating markets for metals commodities that are produced using ?green technologies?. A promising "green" gold leaching system uses a polysulfide based lixiviant which is non-toxic and non-polluting. Laboratory testing has demonstrated selective gold extraction rates comparable to those of cyanide. The polysulfide lixiviant is a dilute aqueous solution which can be inexpensively produced from readily available chemical reagents and even mining wastes. The reagent system is self-buffering and maintains the optimal chemical environment for leaching. Treatment of residual leach solutions is not necessary because the lixiviant itself is not toxic, and breaks down as the system equilibrates. Simple closed system boiling is used to recover gold from process solutions. The polysulfide lixiviant can then be readily renewed and recycled back into the system, forming a closed loop system that conserves reagents and energy which minimizes operating costs. Economic projections have shown that the system can be used profitably for standard ore types and grades.

Jan 1, 2009