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By D. Virely, M. Gasc-Barbier, J. Guittard

"The valleys of the Dordogne and the Vézère (France) have been inhabited since prehistoric times, as evidenced by the famous site of Lascaux. A few miles away, the village of La Roque-Gageac is also a very popular tourist destination (about 1.5 million tourists per year): The village is sandwiched between a massive limestone cliff and the Dordogne river. The collapse of a cave roof high above the village in January 2010 led us to characterize instability together for the cave and the whole cliff and propose a adapted instrumentation to monitor the fracture openings in the rock mass that are linked to climatic variations. Measurements have been going on and been recorded for nearly 4 years. They point out the role of thermal stress fatigue in the breakdown of the rock mass. In this paper we describe the site under study, the instrumentation and its main results. INTRODUCTIONThe phenomenon of thermal fatigue has been very little studied as far as rocks are concerned, whereas it is rather well characterized for other types of materials: Elsevier published a journal dedicated to fatigue (International Journal of fatigue). In the case of rocks, thermal phenomena and their impacts on mechanical behavior have been analyzed from a micro-structural point of view, and it is now well-known that an increase in temperature causes a dilatation of crystals (Arnould et al., 2004; Berest & Weber, 1998). This dilatation may lead to the development of inter-granular traction and compression stresses, and if those stresses are greater than fracture strength, inter-granular and intra-granular cracks may take place. On the other hand, the fatigue phenomenon (cyclic repetition of a temperature variation which is less extreme than the one that may lead to this inter-granular or intra-granular fracture) is a phenomenon which has not been much studied.The principal studies on thermal fatigue on rocks come mainly from the field of geomorphology, particularly in connection with the analysis of the evolutions of past climate that can explain the present shapes of those landforms: those studies remained essentially qualitative and not quantitative. Le Ber & Oter Duthoit (1987) proposed a thermal and thermodynamic approach to analyse the disaggregation of rock masses. This analysis is dedicated to the study of paleoclimates and was implemented to better understand the formation of slope deposits in order to propose transfer models permitting the reconstruction of the climactic conditions contemporary to their appearance. Since deterioration in the cliff only appears after several cycles, it means that it is a gradual and irreversible deterioration which leads to an increase of the « disorder ». Seen from a macroscopic system point of view, this irreversible evolution is quantified by the internal creation of entropy."

Jan 1, 2015

By Toshiaki Akahoshi

Keywords: Wasted catalyst, Hydrodesulfurization, Ammonium vanadate, Ammonium molyb-date, Hydrometallurgical process. The fundamental reactions have been investigated in order to develop a hydrometallurgical process for recovery of molybdenum and vanadium from wasted catalysts generated in the hy-drotreating desulfurization of heavy oil. The principal steps of the process are a mild oxidation roasting of the waste catalysts at temperature around 500°C, leaching of the target metal components with dilute ammoniacal aqueous leachates, selective precipitation of vanadic acid, and ammonium molybdate precipitation. The selective recovery of vanadium as vanadic acid is successfully performed using ammonium sulfate as a salting-out agent. Recovery of ammonium molybdate is based on large dependence of solubility of ammonium molybdate in ammoniacal solutions upon temperature and ammonium salt concentration. In this process, the solution after recovery of vanadium and molybdenum is recycled to the leaching stage of the roasted materials, and the ammonium salts in the process liquor is in the repeated use. Employment of am-moniacal system makes it possible to operate the roasting at much lower temperature than that for the currently operating process.

Jan 1, 2005

By D. Dreher Whetstone, Paul M. Blakita, Christopher M. Reith, Ravi P. Malviya

"Micro-piles are small diameter (5 to 10 inches), cast-in-place piles which can develop high load capacities by bonding with soil or rock. Micro-piles are particularly well-suited for moderate to heavily loaded structures requiring deep foundations in difficult subsurface conditions, such as karst, bouldery mine spoil, or unsuitable fills with concrete debris or other obstructions. Attempts to install conventional deep foundations including driven piles, drilled piers, or auger-cast piles are likely to be fraught with construction difficulties and disputes, delays, cost overruns, and may be unfeasible in some cases. Micro-pile installation equipment is very effective in installing foundations through such overburden or rock materials.This paper presents case histories of Micro-pile installations on two projects with difficult soil/rock materials. The project sites are located in Charles Town, West Virginia and Masontown, Pennsylvania.Charles Town, West Virginia ProjectThe Charles Town project entailed construction of a four-story pre-cast concrete garage. Triad Engineering, Inc. performed a geotechnical investigation for this project (Triad, 2001). The subsurface, geologic, and project specific information described in th is paper are largely based on the aforementioned geotechnical report.Ground ConditionsThe project site is located in Jefferson County, West Virginia, and is mapped to be underlain by the Elbrook Formation. This formation is described as argillaceous, dolomitic limestone with beds of dolomite and aphanitic and algal limestone (Dean, et al. , 1990). The carbonate rocks at the site were characterized as ""moderately solution-prone, highly calcareous and weathers differentially to produce a pinnacled or ""sawtooth"" top of rock profile. (Triad, 2001 )"" Overburden soils consist of low to high plasticity, fine grained residual soils formed by weathering of the parent carbonate rock. The residual soils include variable proportion of sand and rock fragments."

Jan 1, 2005

By Roger L. Goin

Maintaining smooth haulage roads is a key to significant cost savings at Kennecott Copper Corp.'s Bing- ham Canyon copper mine, located near Salt Lake City, Utah. The truck operations section of the mine moves an estimated 300,000 tpd of waste plus some ore to maintain a balanced production cycle. A three-year truck replacement program has produced a dramatic new look in both size and capacity of the truck fleet. Currently there are 95 haulage trucks in the Bingham fleet with capacities up to 150 t. The trend towards the larger haulage units places greater importance on overall truck availability. The impact of a 150-t truck being out of service is far more critical than with the former 65 or 85-t units.

Jan 12, 1974

By Frank V. Hicks

THE following paper-in no sense a technical paper-is a summary of a safety campaign instituted by a coal-mining company to improve an unfortunate safety record. The experience should be suggestive equally to coal and metal-mining companies. With few precedents to follow in the beginning, the course was charted by trial and error. The endeavor, often disheartening, finally resulted in the capture of the most coveted safety trophy in the mining industry, "The Sentinels of Safety," awarded by the Hercules Powder Co. of Wilmington, Del., through the U. S. Bureau of Mines. The period described covers the 10-year interval, 1924 to 1933, the year 1933 being that for which the award was made. The coal company considered has produced annually for a number of years an average of 2,750,000 tons of coal, employing at various times from 1.800 to 3000 men. Prior to 1924, the

Jan 1, 1935

By B. K. Shibler

A highly flexible laboratory-scale fluidized-bed reactor was designed, constructed, and successfully operated continuously at temperatures up to 1,300° C during an investigation of thermal methods for decomposing gypsum. This report discusses briefly the many problems encountered in developing the 10-inch-diameter reactor and describes its design and construction in sufficient detail to enable other research organizations to build a comparable unit. The reactor consists of a 10-inch-inside-diameter vertical tube which can be varied from 6 to 10 feet high; it is formed from 2-and 3-foot sections of silicon carbide pipe. The tube is surrounded by a 3-inch heating space formed by an outer 4.5-inch-thick circular wall of insulating firebrick. A cone-shaped fluidizing chamber is bolted to the bottom of the reactor. Fluidizing gas enters through the bottom of the cone, and ore is introduced by means of a screw feeder connected to an inlet located just above the gas port. A silicon carbide overflow tube of 1.25-inch inside diameter extends upward into the reactor. The depth of the bed is controlled by substituting different lengths of overflow tube. Twin dust-recovery systems, each composed of a cyclone and Fiberglas filter, are attached to two gas outlets at the top of the reactor tube. The reactor is designed for research on both exothermic and highly endothermic reactions. It can be fired externally by means of four natural gas burners that jet tangentially into the annular space at the base of the reactor. Alternatively, it can be fired internally, using a mixture of air or oxygen and natural gas as the fluidizing medium. A separate instrument panel contains flowmeters, manometers, an automatic program controller, and a multiple-point recorder for printing a record of the temperatures measured by thermocouples located at critical points in the reactor.

Jan 1, 1963

By K. L. Bainbridge

This report describes the results of a study to determine which types of, and to what extent, mining wastes can contaminate groundwater through leaching of acid-forming or potentially toxic constituents. The primary focus of this study was on coal mining wastes, especially overburden spoils and preparation plant refuse. In addition, the potential for contamination by leachates from clean coal stockpiles was also examined. The study approach included investigation of (a) the amounts and geographic locations of mining wastes in the United States; (b) the chemical character of mining wastes, especially with regard to potentially acid-firming or toxic constituents; and (c) the extent to which acid and/or toxic components are leached from mining wastes by rainwater. To evaluate the leachability of coal wastes, a laboratory waste leaching method was developed during this study to specifically simulate the leaching process over a long-term. Waste samples collected during this study were also leached by the EPA extraction procedure and ASTM waste leaching method. Results of the three leach test methods were compared to evaluate their relative capabilities to predict the leachability of mining wastes.

Jan 1, 1980

By G. C. Nowlan, A. Illis, H. J. Koehler

At its iron ore recovery plant at Copper Cliff, INCO produces about 17 million pounds per year of a pure, acid-soluble, dense nickel oxide from nickeliferous pyrrhotite. The process used is also applicable to a broad range of ammoniacal nickel-bearing streams. The product has been widely accepted by the chemical, ceramic and electronic industries.

Jan 1, 1970

Large quantities of electrical and electronic equipments are discarded at the end-of-life (EOL) in different industries and house hold applications. Their disposal is creating a challenging environmental problem due to the presence of hazardous metals and non-metallic materials such as epoxy resins and plastics including brominated flame retardants etc particularly in printed circuit boards (PCBs). The recovery valuable metals and separation of hazardous materials from discarded PCBs will not only conserve the resources but also mitigate the environmental pollution. From a recycling point of view for a sustainable society, the studies have been carried out for the recovery of metal values from EOL-PCBs of DVD video players (DVD-PCBs) and vacuum cleaners (VC-PCBs) using physical beneficiation techniques. The concentration of the metals was found to be 43 wt.% and 30 wt.% in DVD-PCBs and VC-PCBs, respectively. Both the PCBs samples were ground in a hammer mill after cutting and their size analysis was carried out. The liberation of the metallic and non-metallic fractions was investigated under the microscope for different size fractions. Subsequently, froth flotation and pneumatic air separation studied were carried out to enrich the metallic constituents. The studies showed the enrichment of metals in coarser particles (-1000 +150 µm) and non-metals in the finer particles -150 µm following mechanical recycling process. A grade of 90 % with 75% recovery was achieved by froth flotation, but lower grade and recovery of 75% and 65% respectively were obtained by pneumatic separation with -1500 µm powders for DVD-PCBs. A grade of 86% metal was obtained by froth flotation with 76% recovery in the case of VC-PCBs. The lower grade of 65% with almost same recovery was achieved during pneumatic separation studies due to lower concentration of metals in VC-PCBs. The studies also showed that the froth flotation is an efficient process for enrichment of metals from both the samples. The process is environmental friendly as no chemicals are employed during entire processing. The higher recovery and grade of metal is expected to be obtained on a large scale beneficiation process.

Sep 1, 2012

The principal activities of the Bureau of Mines Explosives Research Center from July 1, 1963 to June 30, 1964 are described briefly in part 1. Part 2 gives short abstracts of publications that appeared during fiscal year 1964; in general, the research reported in these publications antedates the report period. Part 3 describes a short-term investigation into safety problems associated with shipping of molten sulfur; this investigation is not at present destined for publication elsewhere.

Jan 1, 1965

By M. S. Klima

Proper analysis of washability data can lead to the development of a maximum yield coal preparation plant flow sheet. Simulations, as simple as spreadsheet mass and water balancing, are important in examining yield maximization and middlings liberation. Key to such attribute tracking flow sheet simulations is the distribution model, expressing the probability of a species reporting to the product stream. There are many such models in the literature. This paper examines a functional form that can represent or fit most of the proposed distribution functions.

Jan 1, 1997

By A S. Fogliata, L Bengochea, G Mas, J E. Lazarte

The Culampajß auriferous district is located in the northern sector of the eastern edge of the homonymous hill, Catamarca Province, Argentina. Tajo Largo mine is situated in the southern flank of Las Minas gulch at an approximate height of 3.600 m above sea level. In the studied area main outcrops are orthogneiss rocks of Chango Real Formation. The ore mineral is native gold with a lesser amount of pyrite, chalcopyrite, haematite, limonite, malachite, azurite and covellite. These ore mineral assemblages are disseminated in quartz veins filling tension fractures in the host orthogneiss.Several types of inclusions have been recognised, including three phase H2O-CO2liq-CO2vap inclusions, polyphase inclusions with H2O-CO2 and one or more solid phases, and two phase aqueous inclusions. In the three phase H2O-CO2liq-CO2vap inclusions the Tmclath is about 1¦C and the CO2 liquid-vapour homogenisation occurs at 26 - 28¦C, to liquid phase. The homogenisation temperature of H2O-CO2 occurs at 365 - 380¦C in the aqueous phase. This set of data defined a solution with a salinity of 14, 4 wt per cent NaCl equivalent and a density of 0.84 g/cm3. In the two phase aqueous inclusions the melting temperature (Tm) of -5.4¦C and the eutectic point (Te) in -38¦C indicates a salinity of about 7.5 wt per cent NaCl equivalent, with the probable presence of Ca2+. Density of fluid is about 0.83 g/cm3. Homogenisation temperature ranges between 260¦ and 280¦C. The pressure, temperature and salinity of fluids in the polyphase inclusions suggest an early fluid of high density and high salinity. The three-phase fluid inclusions may be the result of an unmixing-phase separation of post magmatic hydrothermal fluid due to pressure decrease along fractures. It is suggested that the deposit was formed during the late magmatic hydrothermal stage genetically linked to granitic rocks and can be comparable with the intrusion-related gold system of Baker (2003).

Jan 1, 2008

By Lloyd M. Kniffin

[This paper is one of series being prepared by the United States Bureau of Mines on mining methods, practices, and costs in the various mining districts of the United States. It describes the mine of the Hanover Bessemer Iron & Copper Co. at Fierro, Grant County, N. M., which is the only operating iron mine in the southwestern part of the United States. This mine is in a district noted for the great variety of ores that it produces. Within a small area, as shown is Figure 1, there are noteworthy deposits of nearly all the common metals. The ore occurs in lenticular masses dipping at about 50°. An underhand stoping method has been developed that requires but a very small amount of handling of ore. As the ore is very irregular in iron content and also in the distribution of the impurities--chiefly sulphur, silica, and magnesia--a method has to be used that will permit selective mining and will also allow ore and waste to be taken out separately as conditions change. A magnetic cobbing plant raises the grade of the ore shipped about 10 per cent.]

Jan 1, 1930

The extraction and recovery of gold from copper electrorefining slimes by leaching and solvent extraction using dibutyl carbitol (DBC) has been practiced for several decades. Yet, the deportment of some common elements in this process has not been reported. The focus of this paper is to report the behavior of copper, bismuth, silver and selenium during the processing of industrial solutions by batch and continuous extraction on the laboratory scale. It was found that DBC, while an excellent extractor of gold from a highly oxidative chloride leach solution, also loads significant quantities of Cu, Bi, and Se. Silver was not present in significant quantities in the leach solution nor did it load appreciably. The deportment of gold and impurities are reported for batch and continuous operations of a two-stage extraction process using distribution ratios and separation factors.

Jan 1, 2010

By Sam Warren, Antonio Marinucci, Genesis Z. Figueroa, Anne Lemnitzer

Drilled Displacement Piles (DDP) provide an ideal deep foundation solution that combines the benefits of ground improvement with traditional advantages of piling systems. This paper consolidates data from 20 construction projects in which more than 30 DDPs were installed and tested axially. High quality site exploration data (e.g., Cone Penetration Test and Standard Penetration Test) were evaluated to derive geotechnical analysis parameters. The test sites consisted of mostly mixed soil types with strongly stratified layers of sand, silt, and clay. Pile diameters ranged between 40 cm and 61 cm. Test results were compared with predictive methods developed specifically for DDPs as well as methods used in general geotechnical practice. The accuracy of the empirical methods is presented in terms of total pile capacity, pile length/diameter, and soil type. The large majority of all examined methods underpredict the in-situ pile capacities. It was also found that the difference between the tested and predicted capacity is strongly related to the level of improvement in the surrounding soil due to the piles’ installation. A general comparison between predictive axial accuracy and the observed level of ground improvement upon installation is also discussed.

May 1, 2022

By Joachiim Lehner

The application of post-combustion (secondary oxygen) to avoid skull formation on BOF lances was tested in industrial trials. The main findings are that no negative impact on the metallurgical targets (i.e. carbon, temperature and phosphorus at end of blow as well as iron–oxide in the slag) could be observed. The technology is capable of avoiding the buildup of lance skull and consequently increasing the average life of lance tips. The application of post-combustion not only affects the skull formation, there are also interactions with the refractory lining, especially thermal wear, and the utilization of the process gases (CO Recovery) that have to be considered. Special attention has to be paid to the parameters determining the use of secondary oxygen because rather small changes can strongly affect the points mentioned above. Since August 2016, the PCD (Post-CombustionDistributor) lances are used on a daily basis in the steelplant LD3 in Linz.

Oct 30, 2017

By William P. Shinn

It is almost exactly seven years since the last previous meeting of the Institute in this city. In a paper on " Pittsburgh, its Resources and Sorroundings," read at that meeting, I showed that Allegheny County had produced in 1878, " one-twelfth of all the pig-iron,.... two-ninths of all the rolled iron (except rails), over one-eighth of all the Bessemer and open-hearth steel, two-thirds of all the crucible blister and puddled steel, one-fourth of all the glass, one-eighth of all the coal, and one-sixth of all the pig-lead produced in the United States;" and the object of this paper is to show that, great as the record then was, it has been greatly surpassed since.* Population. In my former paper I expressed the opinion that the census of 1880 would show the population of Allegheny County to be in excess of 300,000. The census report made it 355,869. The following shows the growth of the county in population from 1790 to 1880: 1790,...........10,309 1800,........... 15,087 1810,...........25,317 1820,...........34,921 1830,...........50,552 1840.............81,235 1850............138,290 1860............178,881 1870,...........262,204 1880,...........355,869 This makes Allegheny County, in 1880, rank sixth in population of the counties of the United States, whereas in 1870 its rank was ninth. The population of Pittsburgh in 1880 was 156,359, being twelfth

Jan 1, 1886

Conveyor belting-Dunlop Belting Division has published a manual on its Starflex plied conveyor belting. The design section of the manual contains advice on the calculation of tensile strength and horsepower needs while the section on belt selection offers helpful recommendations. Circle 200 on reader service card Hydrostroke feeders-A pamphlet from Kone Corp. highlights the uses and operating principles of its hydrostroke feeders. Circle 201 on reader service card Electric cylinders-A 24-page catalog from Raco International Inc. describes applications for its electric linear actuators in addition to the electronic options for computer - controlled operation. Circle 202 on reader service card High torque drives-T. B. Wood's Sons Co. offers a 56-page booklet providing features and specifications on its high torque drives. Information includes a step-by-step drive selection proce¬dure. (HTD) Circle 203 on reader service card Sludge depth meter-The model 600 sludge-depth meter that locates the sludge bed in clarifiers and settling tanks is described in a four-page bro¬chure from Markland Specialty Engineering Ltd. (600-84) Circle 204 on reader service card Cavity pumps-An eight-page bulletin is available from Robbins & Myers Inc. It features the application of Moyno progressing cavity pumps in handling composite slurry fuels. (400) Circle 205 on reader service card Roller chain-A roller chain catalog shows heavy duty drive chains and other specialty conveyor chains. It is available from Peer Chain Co. (PC200) Circle 206 on reader service card Belt filter-Phoenix Process Equipment Co. has available a pamphlet detailing its belt filter press. The unit is designed to dewater refuse and clean coal, yielding easily handled dry filter cakes. Circle 207 on reader service card Capabilities - Literature from International Mineral Services Ltd. highlights its services and capabilities to the mining industry. Circle 208 on reader service card Motor analysis - How to select the proper electric motor by comparing life cycle costs, power costs, rate of return, and other factors, is described in a brochure from Westinghouse Electric Corp. (SA-11376) Circle 209 on reader service card Cavity pumps - A product application data sheet is available from Robbins & Myers Inc. It details the use of Moyno positive-displacement, progressing cavity pumps in handling ground limestone slurry. (PC-21) Circle 210 on reader service card Dust collectors - "Dust Collector Selection Guide," from American Air Filter, describes dry mechanical collectors, wet collectors, fabric collectors, and electrostatic precipitators. (CAD-1-901G) Circle 211 on reader service card Wet scrubber - A 12-page bulletin from The Ceilcote Co. provides a comprehensive description of its ionizing, wet-scrubber system. (12-19) Circle 212 on reader service card Metric o-rings-Simrit Corp. has published a 16-page brochure detailing its full line of standard metric o-rings. Information includes graphics and dimensional charts, and specific data on materials and application ranges. Circle 213 on reader service card Hearing protection - A 16-page catalog from Cabot Corp., EAR Division, provides information on its hearing protection devices and noise control products. Circle 214 on reader service card Toxic gas detection - Sensidyne Inc. is offering a guide for toxic gas monitoring. A description of the electrochemical sensors, as well as ranges, complete specifications, and interference charts are included. Circle 215 on reader service card Hydraulic bolting systems - Ingersoll-Rand Co. is offering a brochure on its line of hydraulic bolting systems. These systems, hydraulic wrench and power console, are designed for heavy duty bolting applications. Circle 216 on reader service card Temperature monitoring - A brochure describing the Ramsey Engineering Co.'s micromonitor temperature monitoring system is available. Three types of switches are available for monitoring bearing temperatures. (80.300) Circle 217 on reader service card Product catalog - Shadbolt & Boyd Co. has published a product catalog. Among items described are hoist slings and cranes; compressors; hydraulics; wire rope, chains, and fittings; and materials handling and shop equipment. Circle 218 on reader service card Cylinder controls - A 12-page booklet presenting Hanna Corp.'s line of electrical controls for cylinders is available. It features proximity and limit switches for hydraulic and pneumatic cylinders, and standard and 3-amp reed switches for pneumatic cylinders only. (550) Circle 219 on reader service card Slurry pump - Pettibone Corp. has published a 24-page booklet covering its heavy duty pumps made with 'diamond alloy' materials for handling slurries of abrasive materials. Circle 220 on reader service card

Jan 9, 1985

By B. G. Hunt, E. J. Kwasney, W. P. Campbell, S. L. Gertsman

"AbstractIn the separation of lead and zinc concentrates from the ore from Cominco's Sullivan mine at Kimberley, • B.C., an iron sulphide concentrate is also produced, some of which is roasted to provide sulphuric add for the manufacture of phosphate fertilizer. The iron oxide calcine from the roaster is potentially a valuable raw material for the production of pig iron and steel. To evaluate this material, six tons of .pig iron was produced from it in an experimental 75 k.w. electric furnace at Trail. The pig iron alone, and also in varying proportions with structural steel scrap and commercial pig iron, was used in the production of basic electric furnace steel at the Mines Branch Laboratories, Ottawa. Details are given of the steel making and fabrication procedure, of the visual and microscopic examination, and of the extensive series of tests on the steel produced. The steel produced using Cominco .pig iron in the charge showed normal working properties in all tests carried out.IntroductionTHIS PAPER describes (a) experimental work by The Consolidated Mining and Smelting Company of Canada, Limited ( Cominco), at Trail on the production of pig iron .from Sullivan iron concentrates, and (b) a joint laboratory investigation by Cominco and the Mines Branch, Department of Mines and Technical Surveys, Ottawa, to determine the feasibility of making a satisfactory steel from this pig iron."

Jan 1, 1955

By Raymond P. Maloney

The Bureau of Mines investigated the White Mountain mercury deposit, in the Kuskokwim River Basin, to better determine the extent of mercury mineralization and to encourage its development by private industry. A program of diamond drilling, augering, bulldozer trenching, and sampling was carried on during four field seasons, from 1960 to 1963, inclusive. Significant amounts of cinnabar, with only trace amounts of arsenic and antimony, occur in dolomite over an area about 4,000 feet long and 1,500 feet wide. The deposit differs from other mercury deposits in the Kuskokwim River Basin by the absence of silica-carbonate and rhyolite intrusives. Small-scale mining was started in 1963 as the result of Bureau investigation and continued during the summers of 1964 and 1965. The investigations indicate that open pit mining might be the most feasible method of working this deposit.

Jan 1, 1967