Search Documents

By Tomohiro Yamasaki

"At the pre-construction foundations of the controlled waste disposal site built at the Port of Kinuura, the clayey soil account for the most, and with lesser amounts of sand compaction piles and sand mat. The cement deep mixing method (CDM) was used to improve ground impermeability and to reinforce the foundations on the seawall. Laboratory mixing and testing was performed to determine the appropriate quantities of cement additive for clayey soil, SCP sand, and sand mat. The test results indicated that maintaining the design strength of qu = 1,550 kN/m2 would require C = 100 kg/m3 of cement additive for all three soil types (clayey soil, SCP sand, sand mat). The permeability performance needed to improve ground impermeability assumes a permeability coefficient of K = 1.0×10-6cm/s. And the clayey soil satisfied the performance requirements at C = 100 kg/m3. However, to improve grand impermeability of the SCP sand and sand mat required more than 5% of particles having diameters of less than 75 µm. Thus, in the latter two cases, the required cement adding quantity was C = 250 kg/m3. The test specimens at one to two weeks after the created with a permeability coefficient of K = 10-6cm/s became permeability coefficient of K = 10-7cm/s six week later due to the effects of cement solidification. So the permeability coefficient declined about one order. The permeability coefficient three months later tends to decline continued with a somewhat lower.INTRODUCTIONBetween 2008 and 2011, the Aichi Seaside Environment Center constructed the Kinuura No. 3 offshore controlled waste final disposal site at Taketoyo in Aichi prefecture. (see Figure 1). The disposal site offers a landfill capacity of 5.21 million m3 and measures 472,000 m2 in area, of which some 344,000 m2 is a managed controlled sector enclosed within an impermeable seawall."

Jan 1, 2015

Past President Shirl McArthur opened the meeting at 9:30 a.m. He called on the Auditing Committee to give its report. Stan Shubart, who checked the financia1 report of the treasurer, read the report. He asked that it be approved. A motion was made, seconded and carried. Shirl thanked all the committees for an excellent job in making this meeting a most successful one. Special thanks to Park Lamborn for a fine program and to Gussie Whiteside for all her efforts in behalf of the Institute. An increase in salary was voted for the secretary-treasurer. It was decided to return to Vail for the 1979 convention. The Resolutions Committee was called upon to give its report. Roy Coulson, Chairman, submitted the following: (I) RESOLVED, Whereas, in the year since the last convention of The Rocky Mountain Coal Mining Institute, the Institute and the coal mining industry have suffered the loss through death of the services of: O. F. Bridwell C. L. Book O. F. Lewis Frank Kolar O. H. Littrell L. B. Phillippi Weston L. Potter George C. Trevorrow

Jan 1, 1978

By Robert McClure

The detection, recovery and disposal of commercial explosives and explosive waste has always carried a level of risk and requires specialized equipment and technical expertise. Improperly stored, discarded, deteriorated, misfired, stolen or surplus products are often the primary sources of explosives that require safe disposal. Detection and disposal tools available today have advanced significantly due to developments in Counter-Improvised Explosive Devices (C-IED) operations and commercial blasting technology. These technologies have provided safer more efficient ways to detect, investigate and dispose of commercial explosives products in order to minimize property damage and potential harm to disposal personnel and the general public.

Jan 1, 2015

Laboratory experiments show that the delay detonators, either electric (copper coated or aluminium) or non-electric (down-the-hole) as generally used in opencast mines and quarries have some scattering from the actual firing time due to manufacturing inaccuracy and variations in basic ingredients of the product. This scattering varies from 1 to 4 % depending on the product quality. Due to this component scatter, adverse blasting effects like misfires, overbreak, underbreak or fly-rock may occur if the design patterns are not judiciously made. It has also direct impact on muck profile and fragmentation.

Jan 1, 1999

By Darryl Lovato, Ramiro Pereyra, Daniel S. Schwartz

"During an annual inventory of nuclear material, a plated steel container which contained plutonium oxide failed. The container had been packaged for temporary storage but had been overlooked and remained in storage for more than 23 years. Although it was determined that the failure occurred through the slip-top rim, a metallurgical evaluation was requested to help to determine the integrity of the container.Optical metallography and scanning electron microscopy were used to analyze the character and degree of corrosion in the container. The depth of corrosion, measured at approximately 10 µm, did not pose a threat to the integrity of the container. However, the corrosion morphology and chemistry did suggest that a galvanic cell had developed between the tin and steel from the condensation of water. The morphology also suggests that the attack of the steel took place over a series of cycles due to changes of the environment.IntroductionMetallographic analysis was requested as part of the investigation into the mechanism of the failure of a slip-top container (#38621) containing plutonium oxide (PuO2) powder. The container had leaked during a special nuclear material (SNM) annual inventory causing contamination and closure of the vault. A photograph of the container and interior container is shown on the right in Figure 1. An initial investigation established that the source of contamination was the consequence of the failure of multiple layers of containment. Initially by the deterioration of the interior plastic bottle and polyvinyl chloride (PVC) bagout bag, and finally through the lid and steel container interface at a location where tape had not adhered properly [1]. Although the source of the breach was established, it was determined that metallographic analysis was important to establish the extent of deterioration of the steel container."

Jan 1, 2008

By D. R. Wilburn

This summary of international mineral exploration activities for the year 2005 draws upon available information from literature, industry and U.S. Geological Survey (USGS) specialists. It provides data on exploration budgets by global region and mineral commodity and identifies significant mineral discoveries and exploration target areas. It also discusses government programs affecting the mineral exploration industry and presents analysis of the mineral industry based on these data. Two types of information are reported and analyzed in this annual review of international exploration for the year 2005. They include budgetary statistics provided by Metals Economics Group (MEG) and information on regional and site-specific exploration activities in 2005 compiled by the USGS.

Jan 1, 2006

A nine-month investigation was conducted into the effect on coke quality and blast furnace operation of the addition of bentonite and southern coal to the northern coal fed to the coke ovens at the Newcastle steelworks.Additions of 0·3 per cent bentonite or 25 per cent southern coal to the northern coal increased the coke strength from 15-20 A.S.T.M. stability to 25-30 A.S.T.M. stability. It is likely that improved mixing and blending facilities would, in both cases, give a coke of over 30 A.S.T.M. stability.For the same coke strength, the use of 0 3 per cent imported Wyoming bentonite was considerably cheaper than the use of 25 per cent southern coal, but the use of Australian bentonite promises the same coke strength for still lower costs. Other additives such as coke breeze, charcoal, iron ore fines, and certain other finely divided materials, gave relatively minor improvements in coke quality.There appeared to be sufficient improvement in blast furnace operation and production to justify full scale addition of bentonite to improve coke quality, although other variables, particularly iron ore physical quality, overshadowed on many occasions the effect of coke quality. Further coke trials with southern or bentonite will be carried out when ore quality has been improved by the introduction of ore sintering at Newcastle.INTRODUCTIONDuring the period of operation of the Newcastle coke ovens and blast furnaces from April 1960 (when No. 3 blast furnace was blown in after rebuilding) to December 1960, a bentonite coke trial was carried out based on earlier research findings (Gregory, 1959a, 1959b; Felton and Gregory, 1960; Gregory, 1960) that as little as 0 3 per cent to 05 per cent bentonite clay added to northern N.S.W. high volatile coking coals gave a significant increase in coke strength. The bentonite coke trial was followed by trials...

Jan 1, 1962

By Javad Koleini S M

The sources of arsenic compounds vary from As(lll) oxide produced from roasters to wastes containing arsenic from chemical or mineral processing plants. The removal of arsenic via co-precipitation with iron is currently proposed as an acce

Jan 1, 1994

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 Nic Slatalla

Resin anchored rock bolts are an effective tool to control the deformation of an underground opening because they combine high support capacity with fast installation. However, there are still numerous shortcomings concerning the understanding and interaction of the system bolt-resin-rock. Field and laboratory test series have been conducted for evaluating the load capacity and bond strength of resin grouted rock bolts in different host rocks under axial load. This paper describes that the behavior and shear strength of the system bolt-resin-rock depends on the rock type and discusses a simple correlation between peak shear strength and shear stiffness in the ratio 1:1000 which may moreover be helpful for estimating rock bolt capacity after installation.

Jan 1, 2006

By Bobby Dupree

I remember a big problem with a seismograph in the winter two years ago. In response to a citizen’s complaint I placed a transducer near the corner of a two-story home. It was a pretty nice day for the winter months, the people were pleasant, and I had no problems digging a hole to place the transducer.

Jan 1, 2004

By Arthur D. FitzGerald

EDC established an Environmental Review Framework in 1999. Throughout the early fall of 2001, the Corporation held public consultations across Canada to strengthen that framework, leading to a public release on November 15, 2001 of a report summarising the results of these consultations. Following this, the Corporation implemented strengthened environmental review requirements in the form of its Environmental Review Directive, in compliance with legislated amendments to Canada?s Export Development Act that went into effect on December 21, 2001. Over the past few years, there has been a global trend towards an increase in the social and environmental requirements of multilateral/bilateral financial institutions and export credit agencies. More recently, this activity has focussed on capturing institutions that have not yet adopted similar requirements and, more specifically, on developing a convergence of the requirements from institution to institution. This paper describes EDC?s new ERD and some of the initiatives that have taken place or are in process that are moving international financial institutions toward converging their environmental and social requirements for projects in the private sector.

May 1, 2002

By J J. Plumb, P D. Franzmann

A study was conducted to describe the microbiology of the MICCL Monywa chalcocite heap bioleaching operation. Microorganisms were detected in the heap using culture-based techniques and cultureindependent PCR-DGGE analysis of the 16S rRNA gene. The metabolic requirements, temperature and pH optima were determined for selected strains isolated from the heap material. Six strains (BH1-BH6) were enriched and isolated from heap solids and leachate samples. Phylogenetic analysis of the 16S rRNA genes showed that strains BH3 and BH4 were closely related to the acidophilic bacterium Acidithiobacillus caldus and strains BH5 and BH6 were closely related to Leptospirillum ferriphilum. The optimum growth temperature for L. ferriphilum was 41.3¦C and the optimum pH range was 1.1 to 1.5. A new species of Archaea was isolated from the heap samples. Cells of the proposed species, Ferroplasma cyprexacervatum (æcyprusÆ L.n. meaning copper; æexacervoÆ L.v. meaning æto heap upÆ), are non-motile pleomorphic cocci, capable of chemomixotrophic growth with ferrous sulfate and yeast extract. Cells grow anaerobically on ferric iron in the presence of potassium tetrathionate and yeast extract as electron donors. Growth occurs from 14¦C to 63¦C, with an optimum temperature of 55.2¦C. The optimal pH for growth was 1.0 - 1.2. The species was phylogenetically most closely related to Ferroplasma acidiphilum with a 16S rRNA gene sequence similarity of 95 per cent. Molecular analysis of mine samples (16S rRNA PCR-DGGE) detected the above-mentioned cultured strains of microorganisms as well as species of Sulfobacillus and other unknown Proteobacteria. The microbial community of the Myanmar bioleach heaps contained similar levels of diversity to a dump bioleach operation in Chile, but contained greater amounts of biomass than another heap bioleach operation in Australia. The operating parameters of the Myanmar heaps (low pH and moderate temperature) have selected for the growth of moderately thermophilic microorganisms that are more commonly found in extremely low pH acidic mine drainage sites than in heap systems. The novel species of Ferroplasma is thought to be involved in the aerobic and anaerobic cycling of iron within the heap bioleaching environment.

Jan 1, 2004

By Harold C. Price

Prior to Sept. 1, 1928, there had never been constructed what might be termed a long pipe line with electric-welded field joints. A year later more than 2500 miles of electric-welded lines had been completed which varied in diameter from 6 to 20 in., and in length from 50 to 700 miles. This paper discusses methods used on five lines with a total length of about 750 miles. The welding equipment used for the firing line or rolling welds, was 300-amp. generators driven with six-cylinder gasoline engines, and for the bell-hole or tie-in welds, 200-amp. generators driven by four-cylinder gasoline engines. A welding gang consisted of a foreman, 6 to 12 firing-line welders and 2 to 4 bell-hole welders, a mechanic and a tractor driver. Coupons about 1/4 in. thick were frequently cut from completed welds, which showed a cross-section of the weld and an indication of its size and penetration. For tests of tensile strength complete welds were cut out. The tensile strength of 52 welds cut from 420 miles of 12-in. line averaged 50,870 Ib. per square inch. The following results give a fair average of the number of welds made per man per day: on 157 miles of 8-in. line both firing-line and hell-hole welds averaged 15.3—the firing-line average was 21; on 39 miles of 10-in. line the firing-line average was 19.9; on 50 miles of 6-in. line, with unfavorable weather, the average was 17.7; on 424 miles of 12-in. line most of which was welded during the spring, 10.3, and with good weather the average rose to 13 welds per day. The average time for making a complete weld on 12-in. pipe 0.313 in. thick was found to be 30 min. for the rolling weld and 45 min. for tie-in welds. A comparison of costs between electric and gas welding shows that the cost of labor for electric welding is 25 per cent. more than gas, generating cost 61 per cent. less than gas, welding wire 40 per cent. less than gas, and supervision and overhead the same. Estimating 50 per cent, annual depreciation on electric welding equipment, and no depreciation

Jan 1, 1930

By R. K. Koch

The Bureau of Mines produced several series of titanium castings in order to investigate the feasibility of producing commercial-grade titanium castings in bentonite-bonded olivine or zircon sand molds. The use of these molds for titanium casting was investigated as a possible alternative to the industrially used rammed graphite process. Parameters investigated were mold mixtures, mulling, gating, venting, drying, and mold washing. The investigators found that castings with superior ductility and fatigue life, compared with rammed graphite castings, could be made by fume-free pro-cesses in molds bonded by western bentonite, using either olivine or zircon sand. Zircon molds were satisfactory for both light-and heavy-sectioned castings. However, olivine molds were suitable only for light-sectioned castings because the mold-metal reaction became excessive during the pouring of heavy-sectioned castings.

Jan 1, 1981

By K. Sugawara, H. -S. Jeong, Y. Ishiguro, J. Otani, Y. Obara, A. Hirata

A series of measurements of induced stress by the Compact Conical-ended Borehole Overcoring (CCBO) technique was performed within rock mass around a tunnel excavated in a region that an underground powerhouse is constructed under high initial rock stress. In the measurements, a phenomenon of core disking was observed during overcoring. The selecting method of strain data uninfluenced by the core disking was proposed, using X-ray CT scanner. Then, the state of induced stress determined from the selected strain data was discussed, comparing with the state of initial stress. Eine Serie von Messungen von induzierter Belastung mit kompaktem konisch-beendetem Überbohrverfahren (CCBO) wurde in Felsmassen um einen Tunnel ausgeführt, der in einer Region gebohrt wurde wo ein unterirdisches Kraftwert unter hoher anfänglicher Felsbelastung gebaut wird. Bei den Messungen wurde beim Überbohrverfahren ein Phänomen des Core Disking beobachtet. Die gewählte Methode der Belastungsdaten, unbeeinflusst durch Core Disking wurde vorgeschlagen, unter Verwendung von Röntgen-CT-Scanner. Dann wurde der Zustand der induzierten Belastung aus den gewählten Belastungsdaten diskutiert, unter Vergleich mit der ursprünglichen Belastung. Une série de mesures de contrainte induite effectuée avec la technique de forage de sur-carottage compacte à embout conique a été exécutée dans la masse rocheuse autour d'un tunnel excavé dans une région de construction d'une centrale électrique souterraine sous haute contrainte de roche initiale. Au cours des mesures, un phénomène de discage de carotte a été observé pendant le sur-carottage. La méthode de sélection des données de contrainte non influencée par le discage de carotte a été proposée, en utilisant un scanneur de tomographie calculée aux rayons X. Il s'ensuit que l'état de contrainte induite provoquée et déterminé à partir des données de la contrainte sélectionnées a été traitée, en effectuant une comparaison avec l'état de contrainte initiale.

Jan 1, 2003

By K S. Smith, B P. Jackson, P J. Lamothe

The upper Arkansas River south of Leadville, Colorado, USA, contains deposits of fluvial tailings from historical mining operations in the Leadville area. These deposits are possible non-point sources of acid and metal contamination to surface- and ground-water systems. We used stable-metal isotopes to help ascertain metal retention and release mechanisms that influence metal transport from the deposits to shallow ground-water systems. To accomplish this, we excavated an intact core from a small fluvial tailings deposit and performed laboratory column experiments to examine the amount of metals leaching through the core. Deionised water was continuously applied to the top of the core, and effluent was collected from the bottom of the core for a period of about two months. Three saturation conditions were used, including unsaturated, partially saturated, and fully saturated. Reducing conditions developed upon partial and complete saturation of the core. During the unsaturated leaching phase, core effluents were acidic (pH 2.8 - 3.5) and contained elevated metal concentrations. During a portion of the unsaturated leaching phase, stable-metal isotope spikes and conservative tracers were simultaneously applied to the top of the core. The isotopes provide a means to delineate metal behaviour within the core. During the unsaturated leaching phase, the isotope spikes did not exhibit breakthrough with simultaneously added conservative tracers. However, some of the stable-metal isotope spikes did break through when reducing conditions occurred in the core (during the partial- and completesaturation conditions). In this paper, we use Cd as an example of the utility of stable-metal isotopes in geochemical studies. In the case of Cd, after the core was partially saturated, the 111Cd spike was released as evidenced by a change in the Cd isotope ratios in the effluent. This release continued during the fully saturated leaching phase, however, the total Cd concentration did not increase. These results suggest that the 111Cd spike was retained inside the core during the unsaturated leaching phase, and only partially released as reducing conditions developed. Results from this core-leaching experiment indicate there is a large reservoir of water-soluble material within the fluvial tailings deposit, which yields elevated metal concentrations and high acidity, and which may degrade adjacent ground- and surface-water quality. Use of stable metal isotopes in this study facilitated the determination of different metal-retention processes, metal-release processes, and metal sources in the fluvial tailings deposit in response to changing geochemical conditions.

Jan 1, 2003

By Henry P. Chandler

COMBINED sales of abrasive materials in the United States during 1956 increased at about the same rate as the value of the Gross National Product in terms of 1954 dollars,3 which was nearly 3 percent. However, some segments of the industry did not follow the general pattern. Sales of abrasive grinding wheels increased 9 percent in value. Sales of surface-coated abrasives declined 5 percent in quantity hut increased 1 percent in value, Production of crude silicon carbide in the United States and Canada advanced both in tonnage and value, but that of abrasive-grade [ ]

Jan 1, 1958

By W. W. Simpson

During cyanidation of mercury-bearing gold-silver ores, significant amounts of mercury are extracted. The presence of mercury decreases. gold loading and increases mercury stripping time on activated carbon, complicates fire refining of the gold cathodes, and creates a potential health hazard. Addition of calcium sulfide (CaS) to the cyanide leach slurry precipitates the solubilized mercury but also some silver. The Bureau of Mines investigated silver loss during CaS precipitation of mercury. Addition of 0.1 lb CaS per short ton ore to a mercury-bearing gold-silver ore precipitated both mercury and silver. However, if copper was added with CaS, or if the ore contained copper, much of the sil-ver loss was prevented. Addition of 235 ppm Cu with 0.1 lb/st CaS, prior to carbon-in-pulp adsorption, resulted in 89-to 97-pct, 80-to 91-pct, and O-pct adsorption of the solubilized gold, silver, and mer-cury, respectively, on the activated carbon.

Jan 1, 1986

By L. M. Sekhukhune

The atmospheric leaching of copper-bearing matte by acidic ferric chloride solution was studied at the laboratory scale. The aim was to achieve maximum copper and nickel recovery by investigating the mechanisms of leaching, as well as identifying the effect of temperature, and concentration of ferric chloride and oxygen. Djurleite (Cu1.96S), hazelwoodite (Ni3S2), and Ni alloy were the primary phases detected in the matte. The quantitative composition of the matte was Cu 31%, Ni 50%, S 13%. Fe and Co constituted 2%, with platinum group metals (PGMs) accounting for 0.5%. A maximum nickel extraction of 98% was achieved using two-stage oxidative leaching at 90°C and 11 g/L Fe3+ as compared to 65% under non-oxidative conditions. A copper extraction of 99% was achieved in the first 45 minutes using two-stage non-oxidative leaching, and copper was recovered from solution by cementation. Three processes took place simultaneously throughout the leaching process, namely: dissolution, cementation/ metathesis, and oxidation. The leaching process was found to be diffusioncontrolled.

Jan 1, 2014