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By Antonio Mendoza

El presente texto describe el sistema de manejo de agua y aire, las actividades integradoras, preventivas, de análisis y ejecución realizadas para describir la respuesta a los retos del futuro inmediato para alcanzar los objetivos ambientales en la mina Antamina.

Jan 1, 2012

By Carmel Bofinger, Maureen E. Hassall, David Cliff, Eric Stemn

Incident investigation is of utmost importance in most high-risk industries and is often used to improve organisational safety. This study was undertaken to examine the content of past incident investigation reports to determine the effectiveness of the incident investigations. The study uses a semi-quantitative method to assess the effectiveness of incident investigations in the Ghanaian mining industry by evaluating the quality of past investigation reports. The assessment tool consists of five elements with several indicators and rating scales for assessing the quality of an investigation report as a measure of the effectiveness of the investigation. The method was applied to 304 investigation reports of three Ghanaian large-scale gold mines, and the results correlated with incidence rates of the mines to determine if any relationship existed. The results showed that the mines differ significantly in the quality of their investigation reports, suggesting differences in the effectiveness of their investigations. In addition, the incidence rates of the mines negatively correlated with some elements of the assessment tool. In general, the method was found useful and revealed areas where improvement is needed.

By H. R. Wells

The Blackbird district, Lemhi County, Idaho, has long been recognized as a potential source of cobalt and copper. However, the comparatively low grade and small size of the known ore bodies, the small demand for cobalt, and. the lack of adequate roads throughout the region precluded extensive exploration of the early discoveries in the area. Recent advances in alloy metallurgy, accentuated by wartime activities, greatly increased the demand for sources of domestic cobalt. Beginning In 1941, engineers of the Bureau of Mines conducted an examination and exploration program in the Blackbird district. This work was supplemented by an exploration program by engineers of the Howe Sound Mining Co., 730 Fifth Ave., New York 19, N.Y.

Jan 1, 1948

By F. G. Heivilin

There will be 3 billion people moving into cities by 2050. Permitting is both the biggest obstacle and the biggest opportunity for mining. The problem is not if we have the right minerals, but how we can permit and produce it in a ?Sustainable? manner. A ?Permit? and a ?Sustainable Development Plan? may soon be the same thing. How do we produce the minerals we need with: 1. The lowest possible carbon footprint. 2. Social license from community outreach by being a catalyst and not a problem in a ?Green World.? 3. Enhanced water supply during all stages of production. 4. Meeting requirements of our customers for service, quality, & cost. How important is it to have a complete ?Sustainable Development Program?? First, no plan is complete!!! It is a work in progress subject to continuous improvement. We need to work together to get the results we want. The goal of the world communities is to become carbon neutral by 2050. What is the mining community?s goal? Do we have one???? When a Clorox, Colgate Palmolive, Wal-Mart, Toyota, or Caterpillar buys a product, what are your chances of getting an order without a good program in place? The answer is it will be difficult or impossible shortly and you will be requiring the same thing with your suppliers. This is an opportunity if you are in the lead and it soon will be a necessity for most mining and processing companies requiring much extra effort to catch up. For some mines it was a necessity to get most of the SD plan to get permitted. The number of companies in the extractive industries with a full Sustainable Development Programs is expanding rapidly as shareholder demands for transparency continue to grow.

Feb 27, 2013

By G. L. Oldright, Virgil Miller

"This paper is the ninth 4 of a series on smelting in the lead blast furnace, and the fourth on modifications brought about by the introduction of richer charges.ACKNOWLEDGMENTSThe authors wish to express their appreciation to Stanley A. Easton, Frank M. Smith, and A. F. Beasley, and to their staff for the whole—hearted cooperation that made it possible to obtain the data in this publication at the Bunker Hill smelter, Kellogg, Idaho.INTRODUCTIONIn tie account written of the conditions obtaining at the tuyere zone in the blast furnaces at Tooele (R. I. 2965) the authors gave references to articles covering (1) the effect of temperature on the equilibrium 2C0 - CO2 + C, (2) experimental work that has been done on learning the gases existing at various elevations in columns of burning coke, (3) extension of this work to the tuyere zone of an iron blast furnace, and (4) the paper itself gave similar analyses of the gaseous oxides of carbon at the tuyere zone of a lead blast furnace and showed the temperatures obtaining there. There were also references in the above paper to the literature on (5) how the lead compounds likely to be present might be ex¬pected to react. A careful study of the original articles selected as references will give a good background for the present work.The following very brief recapitulation may be convenient before considering the tuyere zone in the blast furnaces at Kellogg. The ""producer gas reaction"" (1) of course goes to the left at increasingly higher rates of speed with increase of temperature. When air is blown upward through a grate and a column of hot fine coke alone, oxygen as such penetrates from some 2 to 3 inches only, under the conditions obtaining as to the amount of surface exposed per unit volume of air. When air is blown at about 20 pounds pressure through the tuyeres in the side of an iron blast furnace into a column of coarse coke (plus furnace charge) it may penetrate for 30 inches before the oxygen is entirely used, burning first largely to CO2. Within wide limits, the rate of feeding air into the furnace has practically little effect on the composition of the gases obtaining in the fuel bed of fine coke, this being true particularly of the gases leaving the bed. Some 10.5 inches above the grate the gases contained 22 per cent of CO by volume, and a little further up the CO2 had practically disappeared. This gave the familiar three zones in both the iron blast furnace and the gas producer; in order of entry of the air, in the first the oxygen burned largely to CO2, in the second the CO2 was reduced to CO, and the third the CO2 was practically absent. In the furnaces at Tooele, conditions were somewhat erratic but the first two zones were present, there being, however, no zone in which CO2 and 02 were both entirely absent."

Apr 1, 1931

By Frank J. Wiebelt

Under a general program to extend the resources of mineral deposits, the Bureau of Mines examined the Quien Sabe antimony mine in October 1948. The preliminary evaluation demonstrated that a diamond-drill program was warranted co establish the tenor and persistence of the veins and permit an estimation of antimony reserves. The Bureau of Mines conducted a diamond-drilling program on the property from December 1949 to May 1950. Ten holes aggregating 2,483 feet were drilled. Nine of the holes encountered antimony-bearing vein material.

Jan 1, 1956

By Aline Tatom

This paper presents numerical and experimen¬tal results dealing with the application of ferric ion oxidation of uranium in acidic media. Conclusions are derived from matching numerical results to experimental data taken on one-dimensional laboratory leaches using ore from a South Texas Coastal plain deposit. Since the numerical results can be made quite general, we are able to extract and quantify the effects of oxidant concentration, flow velocity, mass transfer, chemical kinetics, and competitive oxidant consumers (pyrite and molybdenite) on the experimental results. Our results suggest that the leaching of uranium is a mass transfer controlled while that of pyrite is kinetically controlled.

Jan 1, 1981

By B. L. Razzaboni, P. Bolsaitis

"The formation of reactive oxygen species resulting from the interaction of silica dust particles with red blood cell membranes was investigated; particularly, the effect of surface hydroxyl (silanol) group concentration on the rate of formation of such reactive oxygen species was investigated. The rate of formation was measured indirectly through the effect of catalase, a hemoprotein peroxidase, on silica-induced hemolysis. It was found that the addition of exogenous catalase to erythrocytes markedly reduces the hemolysis caused by silica particles. Furthermore, the amount of catalase required for deactivation of silica per unit area of particle surface is lower for fumed silica particles and calcined crystalline particles than for uncalcined, crystalline silica, suggesting a correlation between the concentration of OH groups at the silica particle surface and its potential for generation of H2O 2• The addition of albumin, a copper chelator, also decreases hemolysis. These results suggest that the hemolysis caused by silica particles is at least partly related to the formation of H2O2 at the particle surface and its subsequent reaction with Cu+ ions. The relationship between the concentration of surface silanol groups on the silica surface and the amount of catalase required to decrease hemolysis may also provide a method for testing potential fibrogenicity of respirable dusts. IntroductionReactive hydroxyl groups on silica surfaces are known to be cytotoxic and are believed to play a major role in silicosis (1-9). It has been proposed that this cytotoxicity results from hydrogen bonding to cell membranes and a resulting increase in membrane fluidity and permeability (4). Surface hydroxyl groups on silica surfaces have also been shown to interact with carbonyl oxygens in cell membranes (1,5). An extensive study by Nolan et al. (6) of the relationship between the negative surface charge resulting from ionized silanol groups and the hemolytic activity of crystalline a-quartz (Min-U-Sil) has shown a positive correlation between hemolytic activity and the surface concentration of silanol groups. These authors demonstrated that the hydrogen bonding of polyvinyl-N-oxide (PVPNO) with silanol groups, as well as the bonding of metal cations to the ionized sm- groups, results in significant decreases in hemolytic activity. Furthermore, it has been found that the complete removal of surface hydroxyl groups from the surface of respirable silica particles nearly eliminates the hemolytic potential of silica (7), suggesting that hydroxyl groups might be involved in other cytotoxic processes associated with silica-induced lung injury. Reactive oxygen species have been .implicated in cellular damage caused by respirable silica particles. Evidence for the presence .of oxygen radical species (02, OH°, H2O2) generated by silica, especially on freshly formed surfaces, has been produced by various investigators. Kalbanev et al. (8) detected H2O 2 in aqueous suspensions of quartz. Electron spin resonance and spin trapping by Shi et al. (9) confirmed the presence of OH"" radicals in aqueous suspensions of quartz, and Gulumian and van Wyk (10) suggested that both glass and quartz produce hydroxyl radicals in the presence of H2O 2 • Gabor et al. (11) detected the presence of malondialdehydereactive lipid peroxides (i.e., lipid-0°) in cultures of macrophages and respirable silica particles using the thiobarbituric acid (TBA) reaction test. Will (12), however, reported that iron enhances the TBA value of peroxidized lipids, and Scheulen and Kappus (19) found that catalase augmented malondialdehyde formation, thereby increasing the TBA values."

Jan 1, 1990

By Francois E. Heuze

The mined geologic burial of high-level nuclear waste is how the favored option for disposal. The underground repositories must keep the waste away from the biosphere for very long times - several thousands to tens of thousands of years. Also, access must be maintained to the vaults for several tens of years, so that the waste can be retrieved, if necessary. Both the excavation of the underground chambers, and the radiogenic heating will disturb the rock mass. The overall rock mechanics problem is to understand and predict the processes associated with these perturbations, and their impact oh the isolation and containment of the waste (3)**. The specific rock. mechanics issues which have been identified for the three candidate hard rocks (basalt, granite, and tuff), are summarized in Table 1. The table also indicates the level of adequacy of our knowledge in the areas of the various issues. Such an evaluation is consistent with the general consensus of the rock mechanics profession, as explained in several key reports and publications (1 to 11). The main shortcomings of today's rock mechanics for waste repositories can be summarized as: ? lack of resolution for remote mapping of fractures in rock masses ? great difficulty in testing large volumes of rocks to determine their mechanical properties.

Jan 1, 1981

By Raymond J. Poletto

This paper describes the special problems that occur with the construction of diaphragm walls and discusses the lessons learned during the repairs of structural walls. Although diaphragm or slurry wall technology and equipment has vastly improved since its development in the late 1950?s, significant problems still occur. Key issues are repairs related to panel joints between wall panels, concrete defects associated with tremie concrete problems, leaks and other defects at tieback reservations or inserts, wall leaks within the plane of the wall and surface repairs. The paper supports the position that diaphragm walls are relatively watertight when properly constructed, but cautions that it is necessary to address potential problems in the design stage and allow for flexibility in construction so that the problems that occur can be corrected once encountered. Due to the fast track nature of most projects the time available for design, detailing and construction is limited. As a result, insufficient attention to detail by any of the responsible parties can lead to imperfections and defects in the wall. The authors describe the nature of these problems and their potential resolution based on ?lessons learned.? The timely response to wall problems is essential to the successful completion of a diaphragm wall project. Appropriate repairs have resulted in largely successful jobs starting with the World Trade Center in New York City. The authors? total 80 years of experience as the engineer of record and designer, inspector and contractor?s representative for the diaphragm wall results in a unique insight to deal with these problems.

Jan 1, 2011

By O&apos

Southern Ohio Coal Company (SOCCO) and the U.S. Bureau of Mines have identified techniques to optimize the use of scrubbers on continuous miners. The techniques provide maximum respirable dust control while maintaining a high output. The use of radio remote control and scrubber help to achieve greater advance between lifts by locating the operator in fresh air during the mining cycle. He is also kept away from newly exposed roof, which is not supported. An alternative to fan-powered scrubber was also evaluated at SOCCO. A high-pressure water-powered scrubber system eliminated the noise associated with fans, and achieved an intrinsically safe system. Experience in the use of these scrubber systems and remote control at SOCCO are discussed.

Jan 1, 1990

By William R. Wayment, David E. Nicholson

The Bureau of Mines studied some physical properties of hydraulic backfills and their paramount characteristics , and made preliminary attempts to compact this type of material . The in- place density of hydraulic backfills affects the properties of strength , consolidation , and water percolation . Dense fills give better support than loose fills . In - place density properties themselves are affected by grain size , grain size distribution , and the particular conditions of sedimentation in a stope ( the amount of work the slurry water does to compact the material ) . Field sampling of in - place densities of fills presently used in four different mines and laboratory and underground compaction tests using a standard concrete vibrator show that the initial in - place density of the cohesionless fill material tested can be significantly increased by vibratory compaction .

Jan 1, 1964

By D. C. Brady

"Within six months from award of a project management contract, Les Mines Dumagami Limitée, Cadillac, Quebec, was operating its new hoisting facility. This was accomplished with less than a six-week shutdown of mine production while still maintaining shaft access for underground maintenance.The work involved installing a refurbished /3.5 ft diameter double drum hoist, replacing a timber headframe with a newsteel headframe, increasing the ore bin capacity from 500tons to 1000 tons, constructing a new substation, and upgrading related facilities.This paper describes the work and methods used by various contractors, Les Mines Dumagami Limitée and J.S. Redpath Mining Consultants Limited to bring this project to a successful completion. It discusses the history of the project from proposal stage through to the design, procurement, scheduling, and construction management. The paper also comments on problems that were encountered and the methods used to overcome them.IntroductionThe Donald J. Laronde Mine of Les Mines Dumagami Limitée (Dumagarni), a gold and copper producer, is located in northwestern Quebec, approximately half way between Val d'Or and Rouyn. The mine started production in the spring of 1988 and the first gold bar was poured in June 1988.Following a request by Dumagami, on February 22, 1989, J.S. Redpath Mining Consultants Limited(Redpath) delivered a proposal to increase hoisting capabilities from 1500 tpd to a minimum of 2500tpd. Although various concepts were considered, Redpath proposed a new hoist house along the same shaft axis as the existing hoist, and located on the site of the existing substation. They would then provide a new substation, replace the headframe with a largersteel structure , gain extra storage capacities by increasing the bin heights, and raising the roof of the bin house accordingly.Although underground mining would have to be stopped for a month, the mill production would be maintained by feed from Dumagami's open pit.Figure 1 shows the original plant layout and Figure 2 represents the general arrangement after the project was completed . Table 1 compares the original hoisting facilities to the new facilities.On March 2, Dumagami awarded Redpath a contract that included preliminary engineering, detailed engineering, procurement and contract administration, and later added construction management. The preliminary engineering refined the initialconcept, selected major equipment, and prepared schedules and capital cost estimates for the total project."

Jan 1, 1991

By David G. Dixon

Although the kinetics of leaching processes are of paramount importance in the design and analysis of nearly all hydrometallurgical flowsheets, these concepts remain poorly understood and, as a result, are only rarely applied to mass and heat balance models. In this second of two papers, we demonstrate how simple yet powerful models of leaching kinetics and other rate processes may be added to mass and heat balance models, and apply these concepts using a spreadsheet model of a simplified pyrite autoclaving flowsheet. In particular, we focus on the interpretation and scale-up of batch leaching data, and on simple means for modeling other phenomena commonly associated with leaching, such as reagent depletion, gas-liquid mixing, and the precipitation of oxides and basic salts.

Jan 1, 2002

CONSTRUCTED WETLANDS (CWs) ?Human-Constructed ?Built Specifically to Remove Contaminants ?Can Treat a Wide Variety of Wastewaters Including Stormwater(SW) ?Three Major Kinds ?Pond Wetlands ?Free Water Surface Wetlands (FWS) ?Sub-Surface Flow Wetlands (SSF) ?HSSF & VSSF

May 1, 2009

By J. Plant

Stream-sediment sampling undertaken to define the regional geochemistry of northern Scotland is described with particular reference to the errors involved. The region is underlain essentially by Moine schists, Caledonian granites and Old Red Sandstone sediments, which are generally characterized by low geochemical relief. Factors in the secondary environment obscure the relationship between trace-metal concentrations in stream sediments and bedrock geology. Investigation of sampling and sample preparation methods indicates that the -100-mesh material is the optimum size fraction for the regional survey of this area: it provides adequate geochemical contrast: it reduced the incidence of spurious high values in the samples investigated and it is available in amounts which are adequate for all the analyses required. Grinding samples improves precision and reduces the preferential volatilisation of metals coprecipitated with hydrous manganese and iron oxides for the optical emission spectroscopic method used initially. A study of the dispersion of metals in the drainage system of an area of Pb-Ba-Mo mineralisation and an area of U-Pb mineralisation, respectively, indicates that a sampling interval of 1 per 2 km2 based on second- or third-order streams is adequate to define anomalous metal concentrations. Regional variation can also be represented on the same interval. Modifications to the sampling procedure to reduce the effects of the secondary environment are complicated by the primary association of Mn and Fe with mineralisation in the area. The ratio of analytical and sampling error to regional variance shows that procedural precision is adequate to prepare regional geochemical maps of northern Scotland, with the exception of Cr, Cu at low concentrations and Pb.

Dec 1, 1971

The Barmac autogenous crushing mill is one of the most successful new comminution technologies to become available to the mining and industrial minerals industries in this decade.The Barmac autogenous crushing mill is an innovative Vertical Shaft Impactor which operates in essence like a high intensity dry ore centrifugal pump with the reduction occurring primarily as a result of high velocity rock to rock impact in a fully rock lined crushing chamber. With applications in a wide range of mining and industrial minerals operations the Barmac autogenous crushing mill presents an opportunity to enhance reduction and liberation whilst providing many cost savings and production increases in new and existing plants.This paper briefly describes the operation of the Barmac autogenous crushing mill and reviews its benefits.

Jan 1, 1990

By Laxman M. Amaratunga

Laboratocy flarmnability tests were perfonned on dust samples from Fraser Mine in a 1.2 L Lindenburg horizontal tube furnace to detennine the percentage of sulphur oxidized during ignition. The explosion pot ential of sulphide dusts depends on their degree of spontaneous oxidat ion, which was measured by the quantitative analysis of so2 gas released during ignition. Test results indicated that dusts with low sulphur content could exhibit a higher degree of oxidation than a sample with high sulphur content. txlst characterisation using image analysis techniques suggests that the structure and the texture of dust are important factors influencing the explosibility of sulphide dust at ignition temperatures. Therefore for safe mine operations% sulphur content cannot be considered as a reliable single index that could be used to predict the potential of a sulphide dust explosion. Physical, chemical and mineralogical characterisation of dust plays an important role in the detennination of suitable indices for the prediction and prevention of sulphide ore dust explosions.

May 11, 1988

By William L. Porter

From the first day of new miner training until the day they retire, mine workers will experience changes due to the normal aging process. It is an unfortunate fact of life that many age-related changes result in diminished physical, sensory, or cognitive capabilities. Of course, workers also gain a tremendous wealth of experience, knowledge, and insight as they age, making them a vitally important resource for their company. Effective leveraging of this precious resource requires both an appreciation of the changes that occur with age and an understanding of methods that can be used to reduce the injury risk that may result. The purpose of this training is to provide the information necessary to accomplish these objectives. Aging workers may not necessarily have a higher injury risk overall; however, the effects of a musculoskeletal injury (MSI) on older workers may be more extreme. MSHA data show that not only does the percentage of MSIs increase when workers are over age 30, so does the number of days lost per injury, as shown in the graph below [MSHA 2005]. [ ] Protecting the safety and health of aging workers requires matching the demands of the job to worker capabilities. This means reducing or eliminating risk factors for injuries, such as heavy lifting, awkward postures, static postures, repetitive movements, and/or vibration exposures. In other cases, it may mean improving visibility or streamlining processes. Designing jobs to accommodate the changing capabilities of older workers will not only reduce injury risk for older workers, it will have the added benefit of protecting younger employees as well.

Jan 1, 2008

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Jan 1, 2011