Search Documents

By R. A. Beall

This bulletin reviews the historical background of the cold-mold arc-melting technology, with specific references to the development that led to homogeneous zirconium ingots. Descriptions are given of modern production arc-furnaces for vacuum melting of troth exotic and conventional metals. Besides zirconium, specific data are given for production of chromium, thorium, and copper. The development of the skull-casting technique for titanium is detailed, and the application of the technique to such refractory metals as molybdenum and tungsten is described. Factors of operation of the apparatus and furnace design are considered.

Jan 1, 1968

By Chris M. Healey

"Abstract- The Jasper Gold mine in northern Saskatchewan produced a total mill feed of 140 127 tonnes at an average grade of 19.0 g/t Au. Both diamond drilling and chip samples from under­ ground workings returned extremely high values, up to 12 851 g/t (375 oz/I) Au over 0.10 meter from a chip sample. In the presence of such extremely high grades, the accurate estimation of reserves is a major problem.ln the first part of this study, production data from the mine were used to evaluate the results of a variety of reserve estimation techniques in this environment. In two out of three cases studied, indicator kriging with assays cut to 342.9 g/t (10 oz/I) gave extremely good results. In the third case, however , indicator kriging gave unacceptable results. Instead, lognormal kriging of uncut data gave the best results.Secondly, from the same database, a number of drill-hole spacings were simulated, and reserves estimated from the simulations. As may be expected, the results of this analysis show increasingly better results with tighter drill-hole spacing. However, even with a 5 m by 5 m spacing the variation from actual grade was quite large. This is not a systematic under- or over-estimation of grade, rather a random scatter of results .The results of this study show very clearly the problems of deriving good estimates of reserves when extremely high-grade samples are encountered. There is a high degree of randomness to this database, so reserve estimation in this situation will remain a high-risk operation."

Jan 1, 1993

By Unkown

To the Membership of the Institute Gentlemen: The Mineral Industry of Canada in 1948 The preliminary estimate issued by the Dominion Bureau of Statistics and tabulated in the Bulletin of January, 1949, indicated that the value of Canada's mineral production in 1948 reached an all-time high of $808,180,216, showing an increase of 25 per cent over the previous record of $644,696,007 established in the preceding year. The output value of metallics was increased by 22.4 per cent; of fuels, by 43.7 percent of other non-metallics, by 19 per 'cent; and of structural materials, by 16.8 per cent. The value of metals produced in 1948 at $483,770,759, was about $87,000,000 more than in the previous year. There were substantial increases in the tonnages of copper, lead zinc nickel, and other base metals produced, but the rises in market prices for such metals accounted for most of the gains in output values. Production of gold at 3,495,403 ounces valued at $122,339,105 indicated an increase in volume of approximately 500,000 ounces and an increase in value of 14 per cent. Despite the benefits provided under the Emergency Gold Mining Assistance Act 1948 the volume of gold produced in the year was still nearly 2,000,000 ounces less than the record of 5,300,000 ounces established in 1941. The value of mineral fuels produced in 1948, at $158,787,255, was 44 per cent above the 1947 total. Coal production at 18,431,250 tons valued at $107,298,757, while substantially higher than in the preceding year was still half a million tons below the record reached in 1942. Striking developments in the Leduc field in Alberta were responsible for bringing the output of crude petroleum in the year to a new high of 12,098,166 barrels, valued at $36,858,959.

Jan 1, 1949

By C. M. Frost

Two Federal Bureau of Mines recycle hydrogenation experiments to prepare catalytic cracking feed stock were made at 3,000 pounds pressure with crude shale oil retorted from Green River (Colo.) shale in the gas-combustion retort. The hydrogenated product from the first experiment, made at 784° F., was used for investigating the effects of nitrogen content on catalytic cracking yields and for determining the quality of the catalytically cracked gasoline. Hydrogenated product containing 0.14 percent or more of nitrogen produced less gasoline when cracked in a CAT "A" unit than was obtained from East Texas light gas oil cracked at the same conditions; product containing 0.10 percent or less nitrogen produced a quantity of cracked gasoline equal to that obtained from the East Texas light gas oil. The catalytically cracked gasoline had research octane numbers calculated to be approximately 95 clear and 103 with 3 ml. of tetraethyl lead. The principal product from the second experiment, made at 828° F., was a low nitrogen content gas oil which was used for investigating the yields of cracked products obtained when it was catalytically cracked to different degrees of conversion. Yields of cracked products, when plotted as functions of conversion, were essentially the same, within the experimental range of the data, as published yields from catalytic cracking of East Texas heavy gas oil; however, yields from cracking the shale-oil product did not display the sensitivity to change of cracking temperature that has been found for East Texas gas oil.

Jan 1, 1960

By K. J. Maggs

The U.S. Bureau of Mines has investigated the chemical vapor deposition of diamond films on tungsten substrates. The effects of deposition parameters on the adhesion of the films was determined. The films were produced using a hot filament chemical vapor deposition system. Parameters investigated were substrate temperature and methane concentration in the feed gas. Film quality, morphology, and composition were characterized by scanning electron microscopy and Raman spectroscopy. Adhesion testing was performed using an indentation technique, and the results were quantified by relating adhesion to interface fracture toughness. Diamond films with well-faceted crystalline morphology with grain size greater than 1 µm had poor adhesion properties regardless of substrate temperature or methane concentration. Diamond films with smooth morphologies consisting of rounded clusters of small (<0.2 µm) diamond crystallites and amorphous carbon phases displayed much higher adhesion, although the conditions that led to the growth of these films are not understood.

Jan 1, 2010

By D J. McDougall

Due to changes in the solid-state conditions of minerals in the rocks surrounding hydrothermal, contact meta-somatic or metamorphosed ore deposits, positive or negative thermoluminescent anomalies may be found in their vicinity. Several types of equipment which can be used for both quantitative and semi-quantitative measurements of the emission are discussed and compared. Methods of selecting, preparing and testing samples to ensure reproducible results are outlined, along with the kind of data which can be obtained from different types of equipment. The normal thermoluminescence of rock-forming min~ erals in the common rock types is noted, and variations in the solid-state conditions in the wall rocks which will cause marked increases or decreases of true thermoluminescence are outlined, as well as the thermolum-nescence-like emissions which are present in the vicinity of ore deposits. Introduction T HERMOLUMINESCENCE occurs when certain crystalline materials are heated to temperatures ranging between 180&apos; and 400°C. The light emission can be ascribed to the release of electrons metastably trapped within the crystal lattice, with peak emissions taking place at temperatures which are more or less specific for a particular set of traps; the area under

Jan 1, 1965

By William J. Coulter

WITHIN the past thirty years the United States has been involved in two tragic, vicious, and costly world wars. To make the world safe for democracy was the reason given for our participation, but the confusion and misunderstanding that prevails all over the world today suggests that war is not the proper approach to the attainment of that utopia. These conflicts were conceived and prosecuted by nations far advanced in civilization and culture. Their best manhood was sacrificed, a staggering tax burden was saddled on their peoples, huge financial losses were incurred, destruction of property was appalling, and cultural and peaceful scientific advancement received a setback that may require centuries to retrieve. Therefore, some basis is established for the conclusion that progress in the past fifty years has been most outstanding in the development of instruments used for death and destruction, and that progress in this direction between the two World Wars would indicate that the next war will go far toward total destruction of world civilization.

Jan 1, 1946

By A. S. Knight

THE breaking and handling of ore is obviously the most important consideration when the layout of a new mine is contemplated. The problem must be attacked with due regard to the claim area of the property, the dip of the orebody, the anticipated percentage of payability, the width of the reef, and the amount of dislocation anticipated by dykes, faults, or sills. Among these, as far as East Geduld is concerned, the three most important items are: Area. 2,640.5 claims. Average dip 12° (from flat to 35°) Average channel width 36 inches. We are fortunate on the Witwatersrand in &apos;chat there is usually sufficient information available from surrounding properties to determine, within narrow limits, the factors mentioned above. With this information avail-able, the choice of layout is not limited, and it will be found that on the Witwatersrand each group has developed its own technique to suit its individual requirements. On East Geduld, the layout of the property for handling ore is known as the endless-rope haulage system. Following is a brief description of the general principles followed.

Jan 1, 1942

By R. Gilman Brown

INTRODUCTION. MINES are interesting by reason of what they have done for man, or of what has been done for them by nature. Not all are interesting on both scores. Many profitable mines are commonplace to the geologist; and many presenting unique geological conditions have been sad failures commercially. The Standard group at Bodie has produced in 25 years, $14,500,000, paying $5,000,000 in dividends.&apos; On the other hand, this output has been mined (almost wholly above the 1,000-ft. level) from a system of more than 100 veins, ranging in thickness-from 0.5 in. of "specimen rock" to 30 ft. of clay and quartz; distributed through a zone about 2,000" ft. in width, and representing from three to five distinct periods of formation. This group, therefore, by reason of its industrial record as well as its geological features, may fairly be regarded as doubly interesting. The Bodie district occupies an island of recent (Tertiary) hornblende-andesite, surrounded by a complex of igneous rocks and breccias. It lies at the summit of the eastern foot-hills of the Sierra Nevada mountains, and within the Great Basin, a few miles from its western edge, marked here by Mono lake on the line of the Great Fault. The average elevation of the outcroppings of the veins may be taken at about 5,700 ft. The andesite projects from south to north in a great tongue, 12,000 ft. long and 5,000 ft. wide, reaching an extreme height at the northern end of perhaps 1,000 ft. above the adjoining small canyons. These separate it from the main mass of the foot-hill

Jul 1, 1907

By W. G. Davenport

A flash furnace can be run many different ways. It can, for example, be operated with: (a) highly 02"enriched, ambient temperature blast and no fossil fuel (b) considerable fossil fuel and hot, slightly Or enriched blast. It can also produce different grades of matte. With all these possibilities, the flash furnace operator can benefit from any technique that will indicate the &apos;best&apos; way to operate his furnace. One such technique is Excel&apos;s &apos;Solver&apos;optimizationroutine#. This chapter shows how our matrices and Excers optimization.abllity can be used to optimize a flash furnace operation. The chapter sets three optimization goals: (a) minimum industrial oxygen + oil cost, $ per tonne of concentrate (b) maximum smelting rate, tonnes of concentrate per hour (c) maximum profit, $ per hour.

Jan 1, 2001

By G. E. Viens

The electric arc furnace has characteristics which make it attractive for a number of metallurgical applications. Some of these characteristics are: high thermal efficiency, the possibility of attaining very high temperatures, low off-gas volume compared to fuel-fired furnaces, no impurities are introduced by the heat source, and impurities in only minor amounts are introduced by the electrodes. It also has disadvantages, the chief ones being the relatively high cost of electrical energy compared to fossil-fuel energy and the fact that, when oxide ores are smelted using carbon as reductant, the off-gases emitted are rich in carbon monoxide. As in many other pyrometallurgical processes, fumes and dust are emitted from melting or smelting operations. In many installations, some or all of the off-gases are flared, thereby wasting their energy and contributing to atmospheric pollution. During the last eight years, a shaft-electric furnace has been under development at the Mines Branch, Department of Energy, Mines and Resources, Ottawa, Canada. This project was initiated to try to overcome, or at least minimize, the disadvantages of the electric furnace. Experience on other projects, prior to the beginning of this program, had indicated that preparation of the charge materials, for example by sizing raw ore, sintering concentrates and crushing and sizing the sinter, or agglomerating concentrates into uniform-sized pellets, could make a substantial contribution towards achieving success in arc-furnace smelting projects; This entire

Jan 1, 1971

By S. Todd Mickleborough

The geostatistical technique of conditional simulation is applied to measure the uncertainty in factor of safety predictions for soil slopes where there is incomplete knowledge of the spatial distribution of soil properties. A case study considers a natural clay slope in Canada. The sequential indicator simulation technique is used as a means for generating a series of spatial maps of soil properties for this site. These maps approximate random draws from the conditional probability density function that characterizes existing uncertainty in the spatial distribution. Factor of safety determinations are then made for each simulated map using the simplified-Janbu approach, where the computations are performed with a new computer program that can operate on irregular spatial profiles of soil properties specified on a discrete grid. A unique capability of this approach is the ability to generate the distribution of factor of safety conditional to the type, position, and value of existing site characterization measurements. This capability should reduce uncertainty in FS predictions.

Jan 1, 1993

By P. H. S. W. Kulatilake

The presence of discontinuities strongly affects the mechanical and hydraulic behavior of rock masses. Joint geometry networks play a vital role in civil, mining, and petroleum engineering projects associated with jointed rock. The need for a realistic representation of joint geometry in rock masses has been recognized. The first part of the paper shows how to build three-dimensional stochastic joint network schemes and also shows how to perform validation studies for these schemes using joint data from the Stripa mine, Sweden. Due to the existence of complex joint patterns, mechanical behavior of jointed rock masses usually exhibit scale effects and an-isotropic properties. A correct understanding of the mechanical properties (strength and deformability) of jointed rock masses is important for designing and performance estimation of structures build in and on rock masses. Beyond a certain volume, the mass proper-ties of the rock may remain essentially constant with respect to the effect of joints. This minimum volume may be used as the element size to represent the equivalent properties of a statistically homogeneous rock mass volume which contains a significant number of joints. This volume may be termed as a "Representative Elementary Volume" (REV) and may be of great importance for engineering purposes. Investigations are underway at both the 2D and 3D levels to look into the possibility of establishing relationships between REV mechanical properties and joint geometry parameters. Recently developed joint geometry modeling schemes are linked with existing distinct element codes (both 2D and 3D) to create a stochastic/deterministic stress analysis approach in achieving the goal. Results obtained so far in this direction are presented in the second part of the paper.

Jan 1, 1992

By Muhammed Şener, Ahmet Gültek

The flotation chemicals are important in mineral processing, and new progress is made in this area day by day. For sanidine purification, some commercial collectors, which can be harmful to the environment, are used. In that respect, the poly(amidoamine) (PAMAM) dendrimers, which are non-toxic for the environment, are good candidates for flotation applications. In this study, the second-generation PAMAM dendrimer was used as a collector to remove magnetite from sanidine by microflotation method, and obtained results were compared with commercial collectors. The results showed that the PAMAM dendrimer is an efficient and selective collector for magnetite. PAMAM adsorption mechanism was determined by zeta potential and FTIR spectra. According to the microflotation results, 87.76% of magnetite recovered at pH 8 by using PAMAM as a collector. It was found that the flotation recovery with the PAMAM dendrimers is similar to the Aero 704 between pH 2 and 6 but less between pH 6 and 9 and more between pH 9 and 12. All experiments were carried out five times and the standard deviation of all results was evaluated with p = 0.05 confidence interval. The second-generation PAMAM dendrimers can be an alternative flotation chemical to the commercial ones concerning usability at a wide pH range, recovery potential, and environmentally benign.

Apr 28, 2023

By Edward H. Bzirdick

THE territory under particular consideration in this article comprises portions of La Plata and Montezuma Counties, situated in the southwestern corner of Colorado, and around the base of the La Plata Mountains. (See Fig. 1.) In southeastern Utah and northeastern Arizona there are several mountain systems whose origin and structure are practically identical with the La Platas so that ore occurrences found in the latter can be hopefully looked for in the former. With this assumption, there is an area around the laccolithic ranges which offers promise for a successful exploration for gold ores. Ore occurrences of the Silverton, Telluride, Rico, or Ouray Districts will not be discussed, although in these areas the Mesozoic sediments are more or less involved within the ore-bearing complex. These have been intensively studied and developed. The idea is to set forth what my mining experience has been within the largely unaltered . Mesozoic horizon which remains around the extreme bases of the La Plazas. This, until recent years, has been almost entirely neglected by prospectors and operators and, so far as similar territory in Utah and Arizona is concerned, so remains.

Jan 1, 1934

By William J. Coulter

WITHIN the United States the problem of meeting maximum production by our metal mines has been solved by: (1) Conservation of man power by mechanization. (2) Increasing man-power efficiency as expressed in tons per man-shift by the adoption of new and more efficient methods. (3) Production from submarginal properties made possible by some form of government subsidy. (4) Selective mining of high-grade areas. (5) Drawing on broken ore reserves and reducing advanced development work to a minimum. (6) Making maximum use of available equipment. (7) Repairing equipment that normally would be replaced. (8) Working a seven-day week on a three-shift basis to get maximum use of equipment and man power. (9) Adoption of incentive plans to increase maximum efficiency and unit production. (10) Important advancement in metallurgy, resulting in larger recoveries. (11) Improvements in safety, health, and general working and living condi-

Jan 1, 1945

By J. D. Doherty

That America&apos;s great coal deposits eventually will be our principal source of liquid as well as solid fuels is generally accepted. Moreover, the day when synthetic oil from coal will begin to supplement our petroleum supplies does not appear to be far off. The American petroleum industry has not spared effort or expenditure in its attempt to keep pace with the demand for oil, and recent production has exceeded expectations. However, the rapidly rising demand for liquid fuels plus the increasing difficulty of finding and developing the new oil needed even to maintain present production rates make it highly unlikely that oil from domestic wells can fully meet future oil requirements. Therefore, it appears that one or more of the following courses must be followed: 1. Curtail oil consumption. 2. Increase imports. 3. Develop new sources such as synthetic liquid fuels.

Jan 1, 1949

By Andrew Gillam

Outline of Presentation ? AMEC overview ? Benchmarked companies ? GRI 3.1 Guidelines ? Best practice examples ? Report content and boundary ? Strategy and profile ? Environmental ? Social GRI G3.1 ? Gold Standard for Reporting ? GRI ? Global Reporting Initiative ? 1997 outgrowth of Coalition for Environmentally Responsible Economies (CERES) and UN Development Program (UNDP) ? Official collaborating centre of UNDP and works in collaboration with UN Global Compact ? Coalition of companies, business organizations, accounting firms, CSR consulting firms and nogovernmental organizations (NGOs) ? Mission: develop and disseminate globally applicable Sustainability Reporting Guidelines ? Now de facto CSR reporting standard; appeal lies, in part, with supported flexibility in reporting approach and scope ? Latest generation G3.1 (March 2011); includes expanded guidance for reporting on human rights, local community impacts and gender

Aug 1, 2013

By Earl M. Woodward

INTRODUCTION Kerckhoff-2 is a 140 MW underground hydro-electric project designed and owned by Pacific Gas and Electric Company and constructed between May, 1980 and May, 1983 by Auburn Constructors. The project is located in the western foothills of the Central Sierra Nevada Mountains, about 30 miles northeast of Fresno, California, and develops the power potential of the lower San Joaquin River and its tributaries between the existing Kerckhoff and Millerton Lakes. The Kerckhoff-2 Project consists of project roads, adits, and access tunnels, service tunnels, power tunnels, powerhouse, tailrace tunnel surge shaft, buss shaft, intake structure, discharge structure, and switchyard. In the 1920s, the Kerckhoff 1 project, consisting of a dam, reservior, tunnel, and 34 MW powerhouse, was built in the same general area as Kerckhoff-2. The tunnel was constructed by conventional methods, and was left unlined. In time, other projects were built upstream, allowing the flow of the San Joaquin River to be regulated. The Kerckhoff 2 project is designed to harness that regulated flow, providing an additional 140,000 ON of power. Kerckhoff 2 will be the primary power plant; Kerckhoff I will produce power whenever the flow rate exceeds 4,800 cubic feet. The new power tunnel is built along the east side of the San Joaquin River between Kerckhoff and Millerton Lakes, parallel to the existing tunnel but extending approximately one mile further downstream.

Jan 1, 1983

By Scott Turner

Since my whole life has been spent in the mining business , I naturally tend to address my remarks particularly to the newly- graduated mining and metallurgical engineers among you . To a certain extent , all forms of engineering principles are involved in the training of the mining engineer , and most sorts of engineering are certainly utilized by him , so that every one of this graduating class is concerned with the field I propose to discuss . The fact that , beginning with to - day , you will always be styled engineers , indicates that you have passed successfully through preparatory school , and have survived the hard grind of the technical college . One object of your training here has been to instruct you in accurate , close , and clear thinking . Your minds have been taught to act directly , calmly . and always to the point . By now , you should know how to get facts , look far , and think through . You are supposed to be willing to recognize and adopt sound engineering principles and practices , in so far as they are known to you , and to furnish character , ability , and devotion to your calling . Some of you may have had a general college course before coming here to specialize in engineering . Where that has been possible , I hope it is the case , since a liberal educational course tends to make the alumnus more flexible and adaptable than the purely scientific graduate. The broader education enables one to change , with less serious loss , from one job to another; ready adaptability is a great asset ; the engineer should be capable of much more than a single special task . The necessary preliminary training for a professional occupation is intellectual in character , involving knowledge , and to some extent learning , as distinguished from mere skill . The well -balanced engineer is expected to embody a happy combination of theory and fact , of pure science and material reality ; experience shows that he is apt to give a good account of himself , once he gets the chance . For the long pull , the importance of unquestioned integrity can not be overemphasized . Leaders of big business sometimes have need for a man as agile and unscrupulous as a cat on a back fence ; on occasion , they may have to employ brilliant , smart , spectacular , and crafty people , but when the special purposes for which such men are hired have been accomplished , they are no longer wanted . Given natural health , intelligence , ability , and adequate training , probably the characteristics most admired in the young employee are steadiness , dependability , and loyalty . The last is the best . If you can not be simple , direct , and faithful in your dealings with your administrative superiors , no one will want you for long . I believe these points are of primary importance to the young engineer . Your groundwork must be right before you can get far . These personal characteristics are what eventually determine your relations with men and affairs . They are vital in the human engineering which may be a large part of your work .

Aug 1, 1932