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By D. I. Bleiwas

Bureau of Mines personnel evaluated the potential availability of nickel from 151 deposits in 18 market economy countries and selected 126 for detailed analyses. An evaluation was made of tonnage-cost relationships indicating the quantity of nickel available at various total costs of production expressed in dollars per pound nickel, including a 15-pct rate of return on the invested capital. The 126 deposits studied contain approximately 73 million metric tons (t) of nickel. An estimated 52 million t is available from laterite deposits, of which less than 2 pct could be produced at $3.50/lb Ni, about equal to the average published price of nickel in 1981. Approximately 21 million t of nickel is available from sulfide deposits, of which about 10.0 million t can be produced at $3.50/lb. Sensitivity studies performed for both laterite deposits and sulfide deposits indicate that the total cost of nickel from laterites is most sensitive to increases in energy costs, and that sulfides are most sensitive to increases in labor costs; sulfides are also sensitive to changes in byproduct revenues. In 1983 the Nickel Mountain mine in Oregon was the only U.S. producer, though development continued on the Gasquet property in California. Of the total 5.1 million t of recoverable nickel in the United States, about 20 pct is available at or below $3.50/lb.

Jan 1, 1984

By V. J. Lynch, A. L. Peyton

"INTRODUCTION AND SUMMARYThe Brewer mine, near Jefferson, Chesterfield County, S.C., was originally operated as a gold mines as late as 1890 this mine was reported to have been one of the large gold producers in the southeast,Occurrence of topaz on the Brewer property was not reported until 1935, when it was discovered by Pardee and Parks. 3/ of the Federal Geological Survey while they were investigating gold deposits in the Piedmont province.During the 1940's the Chemical Engineering Branch of the Tennessee Valley Authority and the Electrotecbnical Laboratory of the Bureau of Mines at Norris, Tenn., investigated topaz from the Brewer mine to determine the possibilities of its use as mullite and for the production of calcium fluoride.From July 1950 through. April 1951 the Bureau of Mines conducted a diamond-drilling project at the Brewer mine to determine the grade and extent of the topaz deposits. Ten diamond-drill holes, totaling 2,344 feet, were completed, and 231 analyses of core samples were made during the course of the project.This report presents factual data relating only to the diamond-drilling project, The placer deposits on the Brewer property were previously investigated by the Federal Geological Survey 4/."

Aug 1, 1953

The long-term production schedule of open pit mines that maximises the net present value (NPV) of a given project relies on the proper design of phases (pushbacks) within the ultimate pit limits. There is not a phase design algorithm applied in the mining industry today that gives yearly production schedules that are optimum.The majority of phase design algorithms currently in use by the mining industry aims at grouping the blocks that fall within the ultimate pit limits into phases such that the average value of the blocks within each phase decrease as the size of the phases increase. Current phase design methods are typically based on a pit limit optimisation algorithm, originally introduced by Lerchs and Grossmann (LG) in 1965. To obtain multiple pit shells to be used for the phase design, the LG pit limit algorithm successively applied to economic block models by changing the price of the commodity or some other factor that properly parameterises the size of the pit. These modified economic block models are developed by predetermining the destination for each block in the model based on a breakeven analysis and highest economic outcome between alternative destinations. Phase designs determined by these existing algorithms may be suboptimal if a given project utilises multiple processing facilities for metal recovery and particularly if these facilities have restrictions (constraints) that require blending of attributes in the feed. To overcome these problems in obtaining phases that optimise overall production schedules, a new algorithm is developed at the Colorado School of Mines. The algorithm determines the phases of an open pit mine by taking into account multiple process options for the blocks and period by period blending requirements. This algorithm has been implemented within a software program (the software) and is being prototyped successfully in the design of improved pushbacks at a copper mine in South America and on a gold mine in Nevada. This presentation will demonstrate the shortcomings of the traditional phase design methodologies based on comparison of results coming from the new approach versus the traditional.

Dec 6, 2010

By Earl E. Hunner

At the end of the year 1914, the main North Star incline shaft had reached the 6300-ft. level, and encountered a vein dipping southwest, or exactly opposite to the North Star. Subsequent development failed to find the North Star vein continuing beyond this intersection, so the 6300-ft. level proved to be the bottom level of the North Star vein, and very little ore was found below the 5300-ft. level. The new vein was called No. 1 vein. Development work carried on for the next 10 years discovered a third vein, called No. 2, branching off about 1200-ft. to the east, with a north-south strike and a west dip. No. 1 vein had about 900 ft. of backs above the 6300-ft. level before reaching the boundary line of the property, and No. 2 vein died out about 800 ft. above. During these 10 years, the money spent on development was increased from $54,000 in 1914 to $184,000 in 1924; the ore reserves steadily diminished until it was evident that the mine must close down unless by some means a large tonnage of ore could be developed quickly. Problems and Plans In order to understand what follows, the general layout and equipment of the mine as it was at this time must be briefly described. Fig. 6 indicates the relative positions of the shafts. The North Star (incline) shaft extends from the surface to the 6300-ft. level following the vein, with an average pitch of 26", between limits of 11" to 38. There is at present no hoisting equipment in this shaft between the 2700 and 4000-ft. levels. The Central (vertical) shaft connects with the North Star shaft at the 4000-ft. level, at a vertical depth of 1600 ft. In two compartments of this shaft 4-ton skips made a vertical turn of 15 ft. radius at the 4000-ft. level and ran down the incline to the 6300-ft. level. A cage operated in the third compartment to the 4000-ft. level. Men and supplies were transferred to a truck running on a third track down the incline shaft to the 6300, operated by an electric hoist on the 4000-ft. station. When the shifts changed double-deck cages were substituted for the skips in the vertical shaft, but they stopped at the 4000-ft. station. The truck to 6300 carried 22 men, and it required 8 min. to make a trip down and back. This arrangement was satisfactory as long as a fairly large proportion of the work was

Jan 1, 1930

By Mary S. Esfandiary

This list of organizations that conduct research and development programs on coal has been compiled by the Bureau of Mines with the thought that such a directory may provide a useful guide to worldwide research efforts in the areas designated and may facilitate communication between organizations with similar interests. This list includes government, university, private, and commercial organizations. Many of these groups are conducting comparatively modest but often particularly interesting or specialized investigations. The areas of investigation have been defined in a broad manner--these include analysis and constitution, mining and geology, preparation, combustion, briquetting, high- and low-temperature carbonization, gasification, hydrogenation, Fischer-Tropsch, and health and safety. In some instances such information is not available, but the names of the organizations themselves often indicate immediate arias of interest. Special publications issued by and describing the work of each organization have been cited, when known; almost all of the organizations also publish results of their investigations in the technical press. Several foreign technical and trade publications that include such information and are not published directly by any of the organizations listed are cited in the pages following the list of organizations in each country. This list is not complete. Information that would improve coverage and/or accuracy will be welcomed by the Bureau of Mines.

Jan 1, 1961

By L. Furtenbach, T. Möller

"Grinding mills are the heart of the mineral processing plant, and are production-critical machines which are required to achieve high availability. Liner wear life and a liner design that promotes ease of installation are important variables to achieve a high level of mill availability. Increased mill size results in more mill internal surface to protect, and more liner components to install and remove. This drives designers toward an increase in liner size to minimize the number of components to be installed by the liner handler. The liner attachment method can also have a large impact on mill availability as well as safety during installation.This paper outlines the experience from the development, installation and follow-up of liners installed in two 38' x 45' AG Mills at Boliden Aitik in Sweden. A new Poly-Met shell liner concept has been developed to minimize the number of liner components. The new Poly-Met shell liner components are made much larger than conventional Poly-Met or steel liners. This reduces the number of components to be installed/removed by the liner handler and helps to minimize installation time and consequently down- time. A new attachment system has also been developed to eliminate the need for the installation crew to be in the “drop-zone” of the shell liners while installing the liner bolts.One interesting aspect of this project was the requirement to predict liner life for these new large format AG mills. The existing 22' diameter mills at Aitik provided a base-line reference for this purpose, and DEM studies were used in the project development stage to predict the wear life of shell liners for the new 38' diameter AG mills. The results from this study are included."

Jan 1, 2012

By Matt Manson

?? Current Exploration and Assessment ?? Overview of Potential Development ?? Infrastructure ?? Opportunities and Challenges ?? Renard? 1-10 kimberlite pipes and ?Lynx-Hibou? kimberlite dyke system within ?Foxtrot? property ?? 50/50 Joint Venture between Ashton (a subsidiary of Stornoway) and SOQUEM ?? Discovered 2001-2003 ?? Québec is routinely assessed as one of the top mining jurisdictions in the world ?? Agnico-Eagle Mines Ltd. Is Stornoway?s largest shareholder and a leading mine developer in Québec

May 1, 2008

By S. C. Schaefer

The Bureau of Mines investigated tIle standard Gibbs energies of formation, 8Gfo, for MllF2 (manganese difluoride) and CoF2 (cobalt difluo-ride). High-temperature galvanic cells employing CaF2 (calcium diflu-oride) as the solid electrolyte were used to measure the open-circuit potentials for the cell reactions ?

Jan 1, 1985

By José Darío Sanabria Cerrón

El presente texto describe la operación de las zarandas de alta frecuencia en la etapa de molienda de las operaciones mineras del país. Durante esta etapa se consume la mayor parte de energía que debe ser aprovechada eficientemente a través de una buena clasificaciónen húmedo de la molienda en minerales para disminuir los costos operativos sobre la base productiva de la planta.

Jul 1, 2015

By S. R. Zimmerley

Recent investigations of finely ground materials have verified Rittinger's law of crushing.4, This law states that the surface produced is proportional to the work expended in the crushing operation. Thus, for a unit of work applied to crushing quartz a definite amount of surface will be produced. Obviously, this amount of work applied to some other mineral will not produce equivalent surface. It follows that in an investigation of mill practice, where ore is being crashed, the relative crushing resistance of the component minerals must be known. In a previous investigation of the Rittinger law,5 the crashing resistance that is, the work required to produce a unit of surface - was accurately determined for quartz. The surface values were obtained by means of the rite of dissolution of quartz in hydrofluoric acid.6 If it were possible so to measure surface on other minerals the determination of relative crushing, resistance would be a simple matter; however, the results obtained on minerals other than quartz by a dissolution method were not encouraging. Moreover, if accurate values could be obtained by dissolution this method could probably never be used on a mixture of minerals such as occurs in an ore.

Jan 1, 1929

By Cale J. Dubois

At Cameco Corporations' Cigar Lake Project, large excavations are developed on the 480 Level and 500 Level must remain stable for at least 15 years to host underground processing infrastructure. Following the successful dewatering of the mine in October 2009, subsequent internal rockmechanics investigations augmented by third party technical investigations; determined that to keep the back of the Water Flush Crusher/Run-of-Mine (WFC/ROMs) excavation stable; required a rehabilitation strategy to mitigate deterioration/deformation of the WFC walls and intersection pillars. The mechanism of failure propagating the movement of the excavation walls is understood to be controlled by the presence of a dominant E-W striking and steeply dipping foliation within a relatively weak and mildly altered rockmass sub-parallel in strike with 14 meters high walls and an intersection span approaching 15 meters. The application of open and resourceful communications between site mining engineers, geologists, contract mining staff, construction management experts, corporate mining and civil engineers, and third party technical experts resulted in a multi-faceted short-term ground support strategy consisting of standard bolting and screening, deep-seated modified-strand cable bolts coupled with heavy gauge mesh straps, rockmass reconditioning using low-pressure grout injection, and horizontal cable-lacing for the intersection pillars applied in lifts using a top-down methodology. The intention of the short-term strategy was to stabilize the excavation so that a long-term structural steel support installation - consisting of composite concrete walls, and arch support applied to the side walls and crown of the back - could be constructed safely. This paper summarizes the evolution of the short and long-term ground support strategy and criteria for the WFC/ROMs excavation developed using elements of civil, mining and hydrogeologic design.

Nov 1, 2011

A research and testing facility has been developed at Simtars to allow the spontaneous combustion testing of coal on a large scale. In this adiabatic reactor, the coal particle sizing is closer to that which could be found in the goaf and therefore the reaction is more likely to simulate the underground situation. This allows aspects of the spontaneous combustion process and methods for detecting a heating to be investigated which cannot be done in an operational mine. Up to 18 tonnes of run of mine or crushed coal is loaded into the reactor and allowed to self-heat while the temperature and gas profiles within the coal pile are monitored. The gases evolved from the coal are analysed using a fixed gas monitor system and gas chromatography to determine which of the common mine fire indicators and ratios can be used to predict the onset and progress of coal heatings. Benchmarking of the inherent propensity of a coal to spontaneously combust at both the large- and laboratory-scale is also possible by comparing the sample against previously tested samples. It has been found that the coal particle size affects both the time it takes for the coal to react and the location of the developing heating. The heatings generate approximately one metre from the inlet but in the crushed coal case do not progress to an advanced heating stage until the æhot spotÆ migrates towards the coal surface where there is an increased oxygen supply. Physical properties such as the compressive strength of the coal also affect the heating size and the time it takes for a heating to develop. Higher strength coals appear to oxidise more slowly and therefore take longer to self-heat as oxidation of the coal is the heat-generating step in the spontaneous combustion process. The best indicators of the state of the heating were found to be CO make and GrahamÆs ratio which are independent of air flow. Investigation of a potential spontaneous combustion should begin as soon as the CO make or GrahamÆs ratio exceed the background levels. The results from the tests undertaken on a number of Queensland and NSW coals are reported here together with the implications for the mining industry.

Jan 1, 2005

By C. L. Kosmoski, B. M. Eiter, B. P. Connor

"In the recent past, the mining industry has witnessed a substantial increase in the numbers of fatalities occurring at metal and nonmetal mine sites, but it is unclear why this is occurring. One possible explanation is that workers struggle with identifying worksite hazards and accurately assessing the associated risk. The purpose of this research was to explore this possibility within the mining industry and to more fully understand stone, sand and gravel (SSG) mine workers’ thoughts, understandings and perceptions of worksite hazards and risks. Eight mine workers were interviewed and asked to identify common hazards they come across when doing their jobs and to then discuss their perceptions of the risks associated with those identified hazards. The results of this exploratory study indicate the importance of workers’ jobrelated experience as it applies to hazard identification and risk perception, particularly their knowledge of or familiarity with a task, whether or not they had personal control over that task, and the frequency with which they perform that task. IntroductionAccording to the U.S. Mine Safety and Health Administration (MSHA, 2015a), 37 mine workers were fatally injured in accidents at metal and nonmetal mine sites between October 2013 and January 2015, following a record low of 16 in 2012 and in 2011. In 2014 alone, 29 mine workers were fatally injured at a metal or nonmetal mine site, and 52 percent of these fatalities occurred at a surface stone, sand or gravel (SSG) mine. In January 2015, Joseph A. Main, Assistant Secretary of Labor for Mine Safety and Health wrote to stakeholders in the metal and nonmetal mining community and identified several areas where improvement was necessary to promote the health and safety of mine workers. One area identified was an increased focus on “daily and effective workplace exams to find and fix hazards” (MSHA, 2015b).Hazard detection is challenging in the mining industry, despite the existence of regulation. Mining is a major undertaking involving the use of complex heavy machinery, equipment and processes as well as numerous and diverse worker activities that take place in a dynamic, challenging environment (Scharf et al., 2001). In other industries that are similarly dynamic and unpredictable, such as the construction industry, a large proportion of hazards go undetected (Carter and Smith, 2006). It is critical that miners are able to both recognize worksite hazards and accurately assess the risk associated with the hazards, because their health and safety depend on their deciding whether and how to remove hazards and mitigate risks."

Nov 1, 2016

By J. G. Groppo

A series of performance studies have been conducted using counter-current column flotation to recover a marketable clean coal product from existing preparation plant fine waste streams. The test work was conducted at several preparation plant sites in Kentucky and Virginia and utilized a 0.15m (6 in.) I.D. column that was 5.79m (19 ft.) high. The refuse streams tested included both thickener feed and classifying cyclone overflow with a typical size distribution of 100 mesh X O. The percent solids of the column flotation feed varied from 1.5 to 15% while the ash content ranged from 30-60%. The concentrates produced contained 2-10% ash with BTU recoveries of nearly 90% using 0.12-1.25 kg/ton (0.25-2.5 lbs/ton) fuel oil and 0.12 kg/ton (0.25 lb/ton) MIBC. These results were consistent with or better than results obtained in preliminary laboratory scale column flotation evaluation. Test results from 7 different seams are discussed as well as scale-up relationships utilized to design a full scale installation presently in operation.

Jan 1, 1990

By Charles J. Stehlik

This report deals with the changing behavior of mine roof bolt and roof rock as a result of repetitious production blasting . Observations were made in the upper shale production headings at the White Pine Copper Co. room and pillar mine , White Pine , Mich . Roof bolt compression pads and a stratascope were used in the investigations , which were carried out in three separate test sites in which nearly identical procedure produced comparative , repetitive , and anomalous observations . Results indicate roof bolt tension change and roof quality deterioration anomalies were coincident with blasting . The hypothesized cause of the anomalies is a seismic shock generated by the blasts .

Jan 1, 1964

By John A. Johnson

The first report of investigations5/ in this series pertaining to the investigation of stemming at the Mount Weather testing adit dealt with dust produced from blasting. The present report discusses the effect of stemming on eases generated by blasting, describes the test procedure, and analyzes the results from, blasting 61 standard rounds. Following care the types of stemming that -,re being investigated: 1, No stemming. 2. Sand in 2 paper cartridges. 3. Clay in 2 paper cartridges. 4. Commercial hydrated lime in 2 paper cartridges. 5. Combustible blasting plugs. 6. Ceramic is blasting plugs with clay in 2 paper cartridges.

Jan 1, 1940

By John A. Johnson

The first report of investigations5/ in this series pertaining to the investigation of stemming at the Mount Weather testing adit dealt with dust produced from blasting. The present report discussed the effect of stemming on eases generated by blasting, describes the test procedure, and analyzes the results from, blasting 61 standard rounds. Following care the types of stemming that are being investigated: 1, No stemming. 2. Sand in 2 paper cartridges. Clay in 2 paper cartridges. Commercial hydrated lira in 2 paper cartridges. 5. Combustible blasting plugs. 6. Ceramic is blasting plugs with clay in 2 paper cartridges.

Jan 1, 1940

By Norman A. Grant

"Location and Transportation FacilitiesTHE BEAVERLODGE area of North Saskatchewan is on the north side of lake Athabasca, 500 air miles northeast of Edmonton.The main Eldorado operation and townsite are on the north •side of Beaverlodge lake, which is immediately north of lake Athabasca and is separated from it by only a mile long portage at Lodge bay. The once famous town of Goldfields. Saskatchewan, and the Box property of the Consolidated Mining and Smelting Company of Canada, Limited, are located on lake Athabasca nine mines from Beaverlodge townsite.Previously, all Eldorado freight was delivered by barge at the Lodge Bay portage, hauled across the portage, and across Beaverlodge lake by small Northern Transportation Company barges, which involved many handlings.In 1952 the port of 'Bushell' was established at Black bay. This is a particularly snug harbour, well protected from the main body of the lake and with good foundations for docking facilities. A Butler building, 300 ft. by 60 ft., and tank farms provide storage at the port. A •road from Bushell to the main Beaverlodge operation, a distance of twelve miles through rugged terrain, was built by the Saskatchewan Government. The cost was shared by the Saskatchewan Government, the Federal Government, and Eldorado and other mining companies.Along this road are located the properties of several enterprising mining companies and near the midpoint lies the ambitious budding town of Uranium. This road has made portaging unnecessary and palletized freight loaded at Waterways, Alta., is now loaded directly on trucks at Bushell and delivered to the point of consumption."

Jan 1, 1953

By Richard L. Sayrs

The Eve Mills deposit is in Monroe County, Tenn., near the southeastern corner of the State. The deposit was examined in February 1943 by a Bureau of Mines engineer, and drilling the property was recommended to increase the on: reserves enough to justify mining should war needs require it. The deposits were explored, by 32 diamond-drill holes totaling 11,649 feet during the periods from July 1943 to November 7, 1945, and from April 1944 to August 17, 1944. The drilling campaign disclosed a large area of mineralization. The ore, however, is apparently confined to long, narrow sheets. The indicated grade of the ore bodies blocked cut by the Bureau of Mines is 4.o8 percent zinc and 2.10 percent iron.

Jan 1, 1949

By Duluth Engineers' Club, Engineers' Club of Northern Minnesota

"The history of Duluth commences with Daniel de Greysolon du Lhut, one of the explorers of the Upper Mississippi who came to the head of the lakes in the summer of 1679. Radisson and Groseillier, and Claude Allouez, a Jesuit priest, are supposed to have visited the head of the lakes, -but there is no authentic record previous to that of du Lhut.In 1792, the fur traders established a fort at Fond du Lac, fifteen miles up the St. Louis River from Lake Superior, but within the limits of the present city •of Duluth. In the early 50's, there were a few scattering settlers at Oneota and around the George Stuntz trading post on Minnesota point. In 1855-6, the settlement on Minnesota point was called Duluth, commemorating the name du Lhut, and organized as a town in 1857. The first board of trustees and town council consisted of -William Nettleton, J. B. Culver; Robert E. Jefferson, Grin W. Rice and William Old: In 1870, the city of Duluth was incorporated, and five years later a portion of the same territory was incorporated as the village of Duluth, and the two municipal corporations were still in existence on March 1, 1887, when the city and the village of Duluth were incorporated as the present city.The first saw mill in Duluth was erected in 1856-57, on the present site of the ship canal. It cut logs from a virgin forest at the upper end of Minnesota point.The first railroad was built to the head of the lakes in 1870. The charter for this road had been granted in 1861 to the Lake Superior and Mississippi Railroad Company, afterward called the St. Paul and Duluth, and which is now a part of the Northern Pacific Railroad."

Jan 1, 1920