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By Richard I. Miller

Science Applications, Inc. has developed for the U.S. Bureau of Mines a rapid response radon monitor capable of accurately responding within three minutes to changing radon levels of magnitude from 100 to 10,000 pCi/1, typical of the levels in working uranium mines. The instrument weighs 17 pounds, is sized 12" x 10" x 6", and is capable of 8 hours of continuous portable operation with a self-contained, rechargeable battery power source. Residual chamber contamination from a radon level allowed to remain in the chamber for 90 minutes is about 10 percent, decaying about a factor of two in one hour. The instrument sensitivity is a nominal 0.1 cpm/(pCi/1), with a background count rate of less than 1 cpm.

Jan 1, 1979

By Kazem Oraee

Falls of ground have historically been the main cause for fatalities in underground mines. Although recent advances in technology have reduced the number of such accidents, when failures occur they usually result in severe consequences. Risks of rock falls, use of heavy machinery and electrical apparatus, entry to confined spaces, working in noisy and dusty environments, and working on unstable platforms are some of the hazards in ground control operations. Managing these risks requires a management regime involving strict adherence to operational codes of practice and an enshrined culture of safety. These should be subsequently reinforced through active participation of management, systematic training, and stringent internal and third party auditing. Accident reports show that the major contributing factor in most rock fall accidents is the failure to adequately manage known risks due to the lack of a systematic process. OHSAS 18001 (Occupational Health and Safety Assessment Series) is an international occupational health and safety management standard specification to develop occupational health and safety at the workplace. This standard is intended to help mine operators control occupational health and safety risks. Addressing the requirements of OHSAS 18001 can be a complex and demanding task. A comprehensive guide for efficient and accurate implementation of this standard is provided in this paper. The discipline can be used to establish an accountable management system foreground control activities in underground coal mines. The paper also provides guidelines for preparing necessary documents, devising safety policies, procedures, performing risk assessment, and handling instructions. Finally, the paper concludes by providing a sound analytical basis in terms of the creation of a robust safety management system foreground control operations in underground mines. Full benefits of implementing an effective and systematic operational health and safety management system are illustrated. The procedure adopted and prescribed in this paper can be used in all underground coal mines where lack of appropriate ground control practices can create deficiencies in both safety and productivity.

Jan 1, 2012

By S. P. Pereira

The mechanized mining cycle using loaders and shuttle cars had it speak in terms of usage in the mining industry during 1950 through 1960. In Brazil, this system is still used at underground coal mines in southern Santa Catarina coal basin. With the aim of investigating the benefits of a new mining scheme using the room and pillar method for these local mines, a computational simulator model was developed in order to investigate the mining cycle. This paper presents the methodology used to develop the simulator and the results that the simulation shows regarding impact of the proposed new scheme on mining productivity.

Jan 1, 2012

By S. P. Pereira

The mechanized mining cycle using loaders and shuttle cars had its peak in terms of usage in the mining industry during 1950 through 1960. In Brazil, this system is still used at underground coal mines in southern Santa Catarina coal basin. With the aim of investigating the benefits of a new mining scheme using the room and pillar method for these local mines, a computational simulator model was developed in order to investigate the mining cycle. This paper presents the methodology used to develop the simulator and the results that the simulation shows regarding impact of the proposed new scheme on mining productivity.

Jan 1, 2012

In practice, frothers are selected following general guidenlies and verification by laboratory and/or plant flotation tests. The terms “powerful” or “selective,” which are commonly used to characetrize frothers, have intuitive rather than scientific meaning. A research program has been set out to study fundamental properties of the flotation frothers and to identify the tests which can provide information needed to characterize and classify such flotation agents.

Jan 1, 2004

By Leslie Burnside

Homestake Mining Co. set out to complete final reclamation at a former open-pit gold mine in west central Nevada. The goal was to exceed regulatory standards by satisfying the company's own high corporate standards for successful reclamation. Homestake's completion requirements challenged available technology due to the unsuitability of heap material as a growth medium, the harsh environmental conditions of the site and the region's lack of native growth medium. Accomplishing these goals required enlisting a multidisciplinary project team to develop, test and implement appropriate and cost-effective revegetation alternatives.

Jan 1, 1999

By Roy Peratrovich

An innovative cost-saving design for a 1,100 ft bulkhead on the Tanana River at Nenana in central Alaska won Alaska Construction & Oil magazine's Construction Achievement Award. The designers utilized materials available nearby at low cost. They planned sheet pile enclosures, self-anchored back into shore without cell closures. They made it practical for inexperienced local workers to do the building. And they completed the project on time and below a reduced budget.

Jan 1, 1985

By D. V. Roberts

Approximately 800 private consulting engineering firms in America specialize in geotechnical engineering. The gross income from these firms totals about $500 to $600 million per year. Sixty-five to seventy-five percent of this geotechnical work is per­formed by consulting engineers that belong to the Association of Soil and Foundation Engineers (ASFE). This paper presents statistics concerning the business activities and functions provided by ASFE member firms. The procedures used in typical projects are described. The paper concludes with a summary of major trends which are impacting the American geotechnical practice today.

Jan 1, 2010

By James Barr

Geology and Mineralogy1 TENNESSEE phosphates are commercially divided into three varieties: Brown, blue and white. The first two only are now of commercial importance. The white phosphates of Perry county are not being mined at present owing to their pockety occurrence. The white phosphate is Fig. I.-DEPOSITS OF 75 PER CENT. BROWN PLATE ROCK UNDERLAIN BY SAND. the highest grade of the three varieties, running often more than 90 per cent. tricalcium phosphate. The brown rock is found in three varieties, grading from the dense almost vitreous gray rock, 76 to 82 per cent. tricalcium phosphate, down

Jan 9, 1914

By J. Janin, J. F. Bougard

Development of improved transportation networks in major urban centers has led more and more to underground construction, the only reasonable solution for decreasing surface traffic congestion. Excavations required by these projects usually cause decompression of the surrounding soil mass which results in subsidence of several centimeters. While these magnitudes of subsidence have no consequences in undeveloped areas, they are often unacceptable in urban areas where existing buildings, structures and utilities are endangered. Recent tunneling projects for the extension of the Paris Metropolitan Transit System (R.A.T.P.) underground network were carried out with this in view and gave rise to the development of a number of innovative techniques for minimizing ground decompression and subsidence. As shown in Figure 1, the recent R.A.T.P. expansion program includes a new express metro, 46 km long, crossing Paris from East to West, and the extension of many existing metro lines in the suburbs. From the start, R.A.T.P. was faced with many unique technical problems for which there was little precedent experience. The structures to be built have large dimensions, with cross-sections typically ranging from 40 to 300 m2, and exceptionally to 600 m2. The new lines are often very deep because the shallow profile is already congested by the existing metro, interceptors, sewers and a very large number of utilities. As a result, new construction is often below ground water level by as much as 20 m. Moreover, the geology varies widely from hard limestone with compressive strength over 1500 kg/cm2 to inconsistent water bearing sand. Finally, curves in the East-West line must have a minimum radius of 500 m which frequently forces the alignment to pass below existing structures, buildings and monuments.

Jan 1, 1974

By Stephen H. E. Phillips

This report outlines the modifications that have been carried out to the original prototype rectangular shaft sinking equipment for its use in a circular shaft. The surface testing of the machine is described where seven, 24 ft. diameter shafts were excavated to an average depth of 21 ft. at rates ranging between 1 ft/hr and 1.9 ft/hr depending upon the prevailing conditions. The durability and productivity standards for the equipment were established indicating that the objectives of the project had been realized. That is, when using the machine the sinking rates could be increased by 25% and costs reduced by a corresponding amount compared with conventional drill and blast methods. In addition it was shown that the machine had been developed to a state of fitness for sustained underground use.

Jan 1, 1981

By S Arai

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Podiform chromitites are commonly found in the Moho transition zone to the mantle section of ophiolites, but have been very rarely found from the current ocean floor, even though some ophiolites are considered as a slice of oceanic lithosphere. One of the factors controlling podiform chromitite formation is the chemistry of host mantle peridotite; an intermediately refractory harzburgite is the optimum host for chromitites. This harzburgite represents the most common lithology of the oceanic lithosphere, where the peridotite-melt reaction, which is another condition, is possibly common there. The oceanic lithosphere mantle is thus a good host for podiform chromitites. The apparent rarity of documented oceanic chromitites is solely due to under-sampling of mantle materials from the fast-spreading ridge and the segment centre of slow-spreading ridges. Some ophiolitic chromitites formed not from genuine mid-ocean-ridge basalt (MORB) but from wet MORB due to the situation of typical ophiolites, which formed not at ordinary mid-ocean ridges but at supra-subduction zone spreading centres.CITATION:Arai, S, 2015. Podiform chromitites do form beneath mid-ocean ridges , in Proceedings PACRIM 2015 Congress, pp 465–468 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Trevor Yeomans, David Yaschyshyn

"Placer Dome (CLA) operates the 90-year-old Dome Mine, in South Porcupine, Ontario.The milling operation currently processes 5 million tons of ore per year, from both the underground and Open pit mining operations, producing 320 000 ounces. The milling process is conventional crushing and grinding, with gold recovery by gravity followed by leach/CIP.Cyanide tailings are impounded in a large (325 ha) tailings area where cyanide is allowed to degrade naturally. Effluent is discharged seasonally during the summer and early fall months to maintain site water balance. Pond water is reclaimed for sole use within the mill process.In 1995, an Effluent Treatment Plant (ETP) was constructed for the purpose of removing dissolved metals and suspended solids. In 1997, an INCO S02/Air cyanide destruction module was added.During this time period, the treated effluent often failed toxicity tests required by the Ontario MISA Regulation, even though effluent chemical parameters were below permit limits. Two studies identified ammonia as the toxicant to Rainbow Trout, and free copper as the toxicant to Daphnia magna.From a literature study, and contacts within the Ontario Mining Association, the use of chelation as a final end of pipe treatment step to render any remaining free copper and metal fractions biologically unavailable was considered. Lab and plant scale tests followed.During the 1999 ETP operating season, the addition of the chelant EDTA (ethylene-diamine-tetraacetic-acid) commenced. To date discharged effluent has passed all toxicity tests.The paper will review the effluent treatment history, current effluent treatment plant operation, and detail the use of EDTA for successful toxicity control.History of Tailings Deposition, and Effluent Treatment From 1910 to 1995Over it’s ninety years of operation, the Dome Mine milling circuit has changed from the original 1910 stamp-mill mercury plant, to today’s modem 14 000 ton per day automated gravity and Carbon in Pulp based plant.By the 19803, a modern mill was operating on mainly underground mined ore. The plant was operating at some 3 800 tons per day, using fairly conventional processing routes.The number 4 tailings dam was being used for tailing’s deposition.All effluent treatment was by natural degradation of cyanide. Discharge was from decanting type structures during the summer months only, maximizing the use of natural degradation no tailings effluent was recycled for Mill use."

Jan 1, 2001

By John A. Johnson

The purpose of this report is to clarify the interpretation of some phases of previous progress reports5/ on the use or omission of stemming that have been brought to the attention of the authors by readers. As the stemming problem was approached from an entirely disinterested viewpoint and the data were presented impartially, results of investigations published in previous reports5/ were obtained under a definite set of conditions and procedure, and they may of may not be duplicated under different conditions and procedure in actual mining practice. Final conclusions regarding the use or omission of stemming in blasting have not been reached pending completion of all aspects of this investigation.

Jan 1, 1942

Executive JOHN M. LOVEJOY, Chairman ERLE V. DAVELER G. B. WATERHOUSE WISER JUDSON WILLIAM WRAITH J. V. W. REYNDERS, Consultant Finance HENRY KRUM, Chairman PAUL D. MERICA R. M. ROOSEVELT H. G. MOULTON, Consultant Admissions. RALPH M. ROOSEVELT, Chairman GEORGE D. BARRON, Vice-chairman JOHN L. CHRISTI PHILIP KRAFT W. A. SINSHEIMER

Jan 1, 1936

By K. Lang

A case study is provided that highlights the successful use of high efficiency electrical submersible pumps (ESPs) adapted from the oil and gas industry for a large scale, open pit mine dewatering operation. In this case, the mine is Goldcorp?s Peñasquito Mine, Peñasco and Chile Colorado open pit development areas in Zacatecas, Mexico. At the time of publication (July 2012), there were 18 vertical bedrock dewatering wells producing an average flow rate of 350 liters per second (lps) from the Peñasco and Chile Colorado development areas. Average pumping rate per well was 18 lps, with a maximum of 44 lps. The depth of wells varies from 330 m to 500m, and includes both in-pit and perimeter (ex-pit) pumping centers. A network of 50 piezometers was used to monitor the response of groundwater levels to pumping. Since dewatering operations were initiated in 2007, groundwater elevations decreased overall, from approximately 1950 m above sea level (masl) to around 1625 masl, for a total of 340 m of drawdown. The pit floor elevation was approximately 1655 masl. All of the producing wells were constructed with 16-inch boreholes, completed with 10-inch diameter blank casing and louvered screen sections and equipped with ESPs. The application of ESPs has proven to be highly effective in the case of Peñasquito?s dewatering operations. Noted advantages include the following: ? Small diameter pump allows use of smaller diameter boreholes (16 inches) and casing / screens (10 inches) reducing well drilling and construction costs ? Greater application range for flow rate and total dynamic head ? Variable speed drive systems for greater energy efficiency and flow rate optimization ? Integration of downhole instrumentation into the motor and pump assembly The advantages and benefits of using high efficiency ESPs revolutionized the dewatering program at Peñasquito open pit mine as evidenced by the number of deep vertical well installations and high dewatering flow rates and total dynamic head requirements.

Feb 27, 2013

The condition of the domestic mining industry is obviously affected by the cycles in general business conditions. This study, the results of which are presented in a series of 78 charts, attempts to examine the interrelationships between the general business indicators and the major statistical measures for the base-metals industries during the cycles in the United States economy following World War II. For these industries the cyclical problem is perhaps less acute than the secular-trend problem. However, short-run fluctuations in production and employment do have very important impacts upon the welfare of the regions which derive a significant portion of their income from base-metals mining and processing industries. Any information concerning the normal patterns of development as the industries enter into a cyclical recession will permit better forecasts and perhaps help promote measures to alleviate the distress that occurs. Also, a systematic study of the comparative movements among the statistical measures during a series of cycles can bring to the fore the economic causation involved, and perhaps, after intensive study, can lead to a better method of short-range forecasting for these industries. This study has not fully achieved these aims. However, observations which significantly aid the interpretation of the current monthly statistics on these commodities are made, and some very general conclusions are drawn. The charts are presented so the interested people can examine them and draw additional conclusions. The charts refer specifically to cyclical analysis. The technique of indexing each cycle to its turning point effectively subordinates the longer term trend movements of the data. Thus, certain general conclusions flowing from this study and from the continuing economic research of the Office of Chief Economist will aid the reader by clarifying the frame of reference within which the charts should be examined.

Jan 1, 1961

By V. Lakshmanan, Dan Mackie, J. Melnbardis

"Crystalline Flake Graphite is a strategic mineral. Since 1954 nearly all North American consumption has been imported from offshore. The Bouthillier Project in Quebec, Canada, is Orrwell Energy's bid to enter the market, with plans to begin production of a 500 TPD operation in 1984.Milling of flake graphite is considered easy, yet more problems have been encountered in flowsheet and plant design than in most other minerals. A fresh approach to existing technology was taken, giving results that are highly satisfactory. The key to graphite liberation without flake deterioration is found to be in autogeneous grinding. In addition to producing marketable coarse graphite by such autogeneous grinding, flotation and tabling, super purity fines can be produced using repeated regrinding, elutriation and flotation. This paper discusses the design of a 500 TPD plant based upon the results obtained from bench and pilot plant studies. INTROOUCTIONWhen the Black Oonald mine at Calabogie Ontario ceased production in 1954 nearly all North American crystalline flake graphite had to be imported from offshore. Orebodies in the United States were too small or too low in grade to be exploited economically.The Houthillier Township near Mont Laurier in Quebec (Figure 1) was a known graphite-bearing area The Orrwell property in that area was delineated in 1957 Some test work including minor footage of diamond drilling was carried out by Italia Copper and the MHM Syndicate prior to 1981 when Orrwell acquired the property"

Jan 1, 1984

By Chen Song

Keywords: Co3O4, Cobalt Compounds, Morphology, Urea, Homogeneous Precipitation Depending on experimental condition, precipitation from cobalt nitrate and chloride solution in the presence of urea yield dispersed cobalt compounds with different chemical compositions and morphologies. The effects of concentration of cobalt solution and urea, agitation, on precipitation morphology were investigated experimentally. Generally in closed systems the particles are identified as cobalt (II) basic carbonate with needle type shape. In open system, spherical and plate-like precipitations of cobalt (II) basic cyanate are formed. The chemical formula of cobalt compounds was confirmed. They are CoII,III(OH)0.83(CO3)0.49 Ay?0.14 H2O (in tightly-capped reactor: A stands for NO3?, Cl?; y[A]molecular weight < 12.9) and CoII,III(OH)0.83(NCO)XAy?0.14 H2O. (in open reactor A stands for: NO3?, Cl?; 42 x + y[A]molecular weight < 44.82). The main reason was that the primary particles had different chemical compositions for the effects of the different kinds of anions and stoichio-chemical compositions of the primary particles. The effect degree of the anions depended on the co-existing anion radius in the reaction solution. According DTA-TG analysis of the cobalt compounds, the latter particles transform to Co3O4 powders on calcining. The shape of the Co3O4 particle with porous character has inheritance with precipitation. In this paper, it concludes that the particle formed by the principle of nucleation-aggregation in aqueous solution. The process of aggregation has played an important role in formation of particles. During calcination, the aggregation would be destroyed partly.

Jan 1, 2005

By John A. Johnson

The purpose of this report is to clarify the interpretation of some phases of previous progress reports5/ on the use or omission of stemming that have been brought to the attention of the authors by readers. As the stemming problem was approached from an entirely disinterested viewpoint and the data were presented impartially, results of investigations published in previous reports5/ were obtained under a definite set of conditions and procedure, and they may of may not be duplicated under different conditions and procedure in actual mining practice. Final conclusions regarding the use or omission of stemming in blasting have not been reached pending completion of all aspects of this investigation.

Jan 1, 1942