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The principle activities of the Explosives Research Laboratory from July 1, 1961 to June 30, 1962, are described briefly in part 1. Part 2 gives short abstracts of publications that appeared during fiscal year 1962; in general, the research reported in these publications antedates the report period. Part 3 gives the results of an investigation which, although too limited to warrant separate publication, merits presentation in some detail because of current interest in ammonium nitrate-fuel oil compositions.

Jan 1, 1964

By Harry R. Nicholls

The objectives of this investigation were to determine the strain propagation laws for a strain pulse in salt and to compare the seismic effects from the detonation of different explosives in salt. The investigation showed that a strain propagation law of the type, e = K(R/W 1/3 ) n, and a strain energy propagation law of the type, Ea/W 1/3 = K(R/WI/3)b , are valid in salt. A change in the regression law coefficient, n , was noted with strain level. A similar change in b was inferred because strain energy is proportional to the square of strain amplitude. Particle velocity data may be used interchangeably with strain data under the test conditions.

Jan 1, 1962

By S. C. Brown

A number of studies have suggested that microscale asperities enhance bubble-particle attachment efficiency; however, in practice the roughening of particulate surfaces can also lead to a decrease in flotation. In the present investigation, it is proposed that nanoscale asperities may be partially responsible for this phenomenon. It is suggested that as inter-asperity separation distances are reduced capillary effects are enhanced leading to the formation of stable liquid domains, which adversely impact bubble-particle adhesion. In addition, obstruction of surfactant self-assembly may occur, further limiting flotation.

Jan 1, 2003

By T. McKeon, G. Luttrell

Spiral separators are commonly used to upgrade sand-sized particles in both the coal and mineral processing industries. Many plants utilize multiple stages of cleaning and/or scavenging spirals to improve recovery and/or final product grade. Field studies suggest, however, that the layout of industrial spiral circuits is often less than optimal. This oversight can usually be attributed to a failure by plant designers to consider fundamental process engineering rules that govern the layout of complex separation circuits. This article reviews some of these important rules as specifically applied to multistage spiral circuit design. Two industrial case studies, one involving the upgrading of heavy mineral sands and a second involving the cleaning of fine coal, are presented to illustrate the impact of good design protocols on spiral circuit performance.

Jan 1, 2007

By Stephen D. Smith

The following tables summarize data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Although crude mineral production may be measured at any of several stages of extraction and processing, the stage of measurement used in these tables is what is termed "mine output." It usually refers to minerals or ores in the form in which they are first extracted from the ground, but customarily includes the output from auxiliary processing at or near the mines. Because of inadequacies in the statistics available, some series deviate from the foregoing definition. For copper, gold, lead, silver, tin, and zinc, the quantities are recorded on a mine basis (as the recoverable content of ore sold or treated). However, the values assigned to these quantities are based on the average selling price of refined metal, not the mine value. Mercury is measured as recovered metal and valued at the average New York price for the metal. The values shown are in current dollars, with no adjustments made to compensate for changes in the purchasing power of the dollar.

Jan 1, 1995

By N Rivera, A Music, C Cisternas

In an underground mine operated with panel caving and subjected to high stresses, geotechnical events such as collapses or rock bursts are fairly recurrent. Both situations can involve risks for people, considerable production losses and increasing operational costs.This paper discusses an operational methodology for the recovery of the undercutting front carried out at El Teniente mine, which uses panel cave mining with post-undercutting, after the occurrence of severe damage due to a seismic cluster. The main objective of the recovery of the undercutting front is to prevent the spread of the collapse to the production level, risking the operational continuity. The methodology is the result of repairs that were carried out in the year 2014 at the North Reserves sector from El Teniente mine. Its characteristics are an undercutting front of almost 1000 m long, with the presence of relevant structures and faults, high stresses and high seismic activity.The practical implementation of the proposed methodology was successful since it prevented the spread of the damage, completely recovered the undercutting front and avoided production losses during the execution of the repairs. Also, considering the origin of the damage and the operations associated to the subsequent recovery of the undercutting front, in this paper we discuss the main control variables to be measured. These variables should allow any operator and short-term planner to take action in mines operated with conventional panel caving in a complex geotechnical environment.CITATION:Rivera, N, Music, A and Cisternas, C, 2016. Recovery of the undercutting front in a mine with conventional panel caving – case study at North Reserves sector, El Teniente Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 713–722 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

THE CHAIRMAN.- This meeting is under the auspices of the American Institute of Mining and Metallurgical Engineers, and I think the germ of the idea originated in the steel business. Last year there was a meeting of prominent people in the steel industry with the idea of getting together and discussing practical phases of their business, so that everybody could contribute and from that there might be benefit derived for the industry. Several months ago when Mr. Bain was in Salt Lake City, he and Mr. Oldright asked me what I, as an individual, thought of it. From that originated this idea of having the copper people come together to discuss reverberatory smelting and all its phases. In starting out, it seemed the best plan to ask members what particular subjects they wished to discuss first; that is, the ones that would be considered more important. We asked Mr. Oldright, or suggested sometime ago that the meeting be postponed until May because May is a lovely month in Salt Lake. There are a number of attractive features around the city. We have a number of smelters here and I think that probably the most of the benefit will be derived from talking in an informal way and visiting the various plants around. the valley. At any rate, speaking as a resident of Salt Lake, I am glad to see all of you gentlemen here, and hope you have an interesting and instructive time. The tentative list of subjects for discussion at this conference is as follows: Construction Walls, etc. Walls, proper design and thickness of brick for various types of charging. Bottoms, construction of. Binding steel, correct weight and arrangement, where thrust of arch should be taken. Refractory materials, feasibility of using different material in various parts of the furnace. Water jackets, where applicable. Should bricks be used inside of same. Gas space, proper design for, height of roof above bath, etc. Roof Shape of Roof, in hot zone and elsewhere, longitudinally. Construction of roof, in various zones, around openings.

Jan 1, 1930

By M. Clair Smith

This report is one of a series being prepared by the Bureau of Mines on exploration, development, mining methods, and costs at various open-pit mines in the United States. These reports have been prepared in cooperation with various mining companies. A similar program, conducted from 1928 to 1939, was generally conceded to have contributed to improving the efficiency of mining operations. The purpose of these reports is to promote development and conservation of our mineral resources by disseminating technological information on mining methods and practices. This report describes exploration, development, equipment, and mining by open-pit methods of the remainder of an ore body that had been previously worked by underground methods. The Tripp pit of the Consolidated Coppermines Corp. is located at Kimberly, Nev., a small mining company town having an elevation of 7,250 feet, 9 miles by road west of Ely, Nev. (fig. 1). The pit extends over the area formerly mined by underground methods from the Morris and Brooks shafts.

Jan 1, 1962

By Wilfred P. Schmoe

Introduction An integrated oil company has two options in approaching strategic planning. It has to decide whether it is in business for the long-term. I state this in all seriousness. Those who help manage public companies have the responsibility of good stewardship of other people's money. We must decide whether continued investment in our basic business will generate a reasonable rate of return. With a world surplus of petroleum production capacity, and continuing downward pressure on prices, this question should be addressed by all oil companies. And a positive answer is not necessarily a foregone conclusion in all cases. The decision should be made based on proven competence in finding and developing petroleum reserves on a cost-competitive basis with other producers, and on a frank analysis of future prospects. This should include a realistic assessment of the projected rate of return on specific investment projects. If a company did not pass these tests, its strategy could take one of four paths. Diversification First, it could diversify. But recent history suggests that oil companies are not good at managing other businesses. Second, it could seek a buyer for its business at the optimum return for its owners. Third, it could sell its assets on a piecemeal basis. And, fourth, it could adopt a longer-range plan of self-liquidation by living off current recoverable reserves. In other words, by not investing in exploration and development, it could maximize short-term profit and pass the money back to shareholders in the form of dividends. The Conoco component of DuPont has a below-average cost of finding petroleum, a good track record of efficient production, and a full plate of projects that pass the test of return-on-investment. In short, Conoco is in business for the long-term. That fact, in itself, determines at least one key element in strategy. This is to extend the life of the petroleum reserve base while at the same time maintaining maximum efficient rates of production to provide a strong cash flow. A company that is able to maintain a strong reserve base will ultimately see the value of those reserves escalate as world oil supplies tighten. Our planners expect this tightening to occur within the next decade as demand grows and production in non-OPEC areas of the world begins to decline. An exploration program tailored to meet the requirements of reserve replacement and current production should have two basic parts. The first is relatively low-risk exploration in proven oil provinces. This is augmented by

Jan 6, 1985

By Thornton L. Neathery

Geologic investigation of a mineralized zone in eastern Alabama indicates that large quantities of talc and soapstone are scattered over a wide area close to the surface. Laboratory experiments show that this material may be upgraded to a high-quality talc. A market survey indicates that the talc deposits may be of current and long-range interest. The anthophyllite asbestos which is associated with the talc does not appear to occur in sufficient quantities to be considered as a primary commercial source.

Jan 1, 1967

The modelling of lithological domains is a critical step in mineral resource and reserve evaluation. Deterministic models rely on an interpretation of the available drill hole data and expert knowledge, but do not account for the uncertainty in the spatial extent of the lithological domains. Instead, probabilistic models based on conditional simulation can be used to map the probabilities of occurrence of the domains within the deposit, which reflect the uncertainty in their presence or absence at unsampled locations. The mineral grade model is then obtained by weighting the predicted grades associated with each lithological domain by the probability of occurrence of this domain. Such an approach accounts for the continuity of the grades proper to each lithological domain and for the uncertainty in the spatial extent of these domains within the deposit. An application to a porphyry copper deposit is presented. Keywords: spatial uncertainty; plurigaussian simulation; geological control; kriging; geostatistics.

Jan 1, 2007

This report covers the results of an industrial engineering study that assessed the safety and efficiency of underground ore handling in U.S. metal mines. Significant conclusions that will be of benefit to the entire mining industry are the following: It appears from the study that the productivity of the slushing equipment itself cannot be substantially increased using the existing technology; the unsafe situations associated with slushers can be improved by better anchoring practices, by providing better work station layout that incorporates improved clearances and protected walkways over the ore pocket, by lighting the slusher drift, and by improved operator training; improved technology needs to be applied to the movement of broken ore in the stopes; and slushers will continue to be used in the mining industry in certain spedial and unique situations outlined in the report.

Jan 1, 1974

By Fred P. Giese

Southeastern reserves of titanium ores are large, widespread, and ample for anticipated demand. The leading titanium industries are mining and beneficiating sand deposits, principally in Florida, and manufacturing titanium pigments. Most of the mineral output is consumed by the producers themselves. In 1962, 20 percent of the national pigment capacity was in the Southeast.

Jan 1, 1964

By J. R. McVey

A 10-channel automatic data acquisition system has been designed and environmentally packaged for use with underground strain-gage applications and associated instruments. The system uses commercially available components and is assembled in two plastic enclosures. Environmental control is provided through a specially designed (compressed-air) air-conditioning system and water-resistant cabling. Accuracies of 0.01 pct and resolution of 1 µV have been obtained in underground tests.

Jan 1, 1973

By D. Harrington, G. S. Rice, R. R. Sayers

"The Bureau of Mines in Serial No. 2606,4 issued in May, 1924, gave tentative specifications for rock-dusting to prevent coal-dust explosions in mines. Subsequently, a sectional committee of the American Engineering Standards Committee was appointed to formulate recommendations for standard practice in rock-dusting coal mines. The report of this Committee which follows was approved by the American Engineering Standards Committee, December 30, 1925. Several members of the Bureau of Mines staff served on this Sectional Committee and its recommendations are essentially in harmony with those of the Tentative Specifications in Serial No. 2606.As certain explanatory details contained in that serial are not included in the recommendations formulated by the American Engineering Standards Committee, it should be considered by coal-mine managements in conjunction with the committee's report which follows:Recommended American Practice for Rock-Dusting Coal Mines to Prevent Coal-Dust Explosions 1. Definitions of Terms Used: The term ""Mine"" shall include all underground excavations from which coal is hoisted or transported to the surface, through one or more openings.The term ""Main Haulage"" shall include all underground slopes and planes, all rock tunnels, and all entries excepting those from which rooms or chambers are turned.The term ""Entry"" shall include all underground haulageways, travellingways and airways, excepting working places as defined below:"

Mar 1, 1927

By Stefano Trevisani

Abstract The FIEC Sustainability Vision states that “risks should be identified and allocated in a fair manner across the project team from the early stages of the design phase. A partnering approach, where objectives and timescales are agreed in advance together with all relevant partners in the value chain, offers a useful solution to improve on site efficiency and reduce disputes”. An alliance or collaborative form of contract involving all parties is the best way to ensure fair contract conditions and proper risk allocation in construction projects. Collaborative contracts are particularly useful where there is uncertainty or undefined information or in the event of technical difficulties and other risks difficult to allocate among the parties involved in the project. Owners sometimes require even special output in terms of innovative technical solutions or special performance. In addition, this particular form of cooperation has been construed and developed with the intention of avoiding and mitigating another great risk associated with the construction industry (especially in complex projects): disputes and conflicts, which are often a major cause of delays, increased costs, loss of reputation and opportunities. In contrast, Alliances are a way to increase and strengthen business relationships, technical and economic innovation and effectiveness, in a worldwide global context where the waste of resources must be avoided in order to guarantee future recovery and growth. Of course, the total cost of a project is usually a key factor and the main driver for the Owner and the Contractors in deciding the type of relationship between them as well as the subsequent relationship with subcontractors and lower-tiers. This paper and presentation, will explain the main features and the principle benefits that the use of collaborative contracts can bring to all parties involved in the construction project, including the sustainable financial return that might be achieved if costly and time consuming disputes can be avoided.

Jan 1, 2014

By F. Haessner, M. Wilkens, U. Jakubowski

ThOUGH at present there is a wide range of possibilities for the quantitative determination of preferred orientations, pole figures of identical specimen material have not been determined by different methods as yet.''' In this paper a comparison of (Ill), (200), and (220) pole figures is presented which were obtained from a 95 pct cold-rolled high-purity cop- per sheet (99.9998 pct Cu), by three different methods. The three methods are: a) The combined X-ray reflection-transmission technique of plane samples by schulz3 and Decker, Asp, and Harker. 4 A Siemens texture goniometer was used. The experimental details are described elsewhere. 6 b) The X-ray reflection technique of spherical samples by Jetter and Boric.' A Siemens texture goniometer with some modifications was used. The samples were prepared by sticking 140 polished sheets together with an adhesive and machining a sphere (20 mm diam).* Additional

Jan 1, 1967

By K Faure

At Sams Creek a gold-bearing, peralkaline granite pophyry dike intrudes Ordovician-Silurian metapelite and quartzite. These metasedimentary rocks have undergone three phases of folding: a first phase of recumbent folds (F1), a second phase (F2) of northerly-trending inclined folds with a prominent crenulation cleavage, and a third phase (F3) of steeply plunging folds. The granite porphyry dike has a thickness of up to 40 m and intrudes thin lamprophyre dikes along its contacts. Deflection of the crenulation cleavage around the granite dike, shearing within the dike and its sinuous outcrop pattern indicate that the granite dike has been deformed during F2 and F3. The granite has been hydrothermally altered, with a first stage of magnetite-ankerite alteration. This first stage is cut by a second stage of quartz-pyrite veins and a third stage of sulphide, quartz and ankerite veins, accompanied by pervasive silicification represented by quartz-perthite-albite-rutile¦pyrite-ankerite-sericite assemblages. Lamprophyre is altered to an ankerite-chlorite-sericite assemblage. The sulphide veins are composed of arsenopyrite + pyrite ¦ gold ¦ galena ¦ sphalerite ¦ chalcopyrite ¦ pyrrhotite. The altered granite and the veins have been deformed and recrystallised. The competent sulphide minerals pyrite and arsenopyrite are fractured and brecciated, with fractures locally filled by galena, a ductile sulphide mineral. Vein quartz shows local cataclastic and mortar textures and develops pressure shadows around arsenopyrite. Alteration and mineralisation are confined to the granite porphyry and adjacent lamprophyre. These features together with the style of veining and the sulphide mineralogy indicate that the mineralisation was formed from a magmatichydrothermal fluid that was sourced from the granite. Oxygen, carbon and sulphur isotope values of the vein minerals (quartz, ankerite and sulphides) are also consistent with a magmatic source.

Jan 1, 2003

By AIME AIME

Annual net production of crude oil from the Anglo-Iranian, Oil Company's fields in Iran for the years 1940 through 1945 amounted to: YEAR TOTAL PRODUCTION (Long Tons) 1940 8,626,639 1941 6,605,320 1942 9,399,231 1943 9,705,769 1944 13,274,243 1945 16,835,000 (preliminary figure) All developed fields were on almost continuous production throughout the war, though their operation naturally was hampered by war conditions, which affected particularly supplies of equipment.

Jan 1, 1946

By E. P. Pfleider

Important economic planning by industries, companies, financial firms and governments is predicated on estimates of future growth potential. Prior to the passage of the Taconite Amendment by the people of the State in November 1964, various admittedly conservative forecasts were made of the future of Minnesota's iron ore industry. Since that date, 3 new taconite plants are under construction, 2 are being expanded, one has just gone "on stream," and a seventh is in the design stage. These plants have a total capacity of about 35 million tons of pellets annually. The pessimism of 1964 today is being replaced by unbounded optimism. In the light of such recent developments, it becomes essential to update forecasts related to production, employment and capital investments. New projections show 50 to 58 million tons of pellet production from Minnesota by 1975. This tonnage, together with some 6 to 8 million of natural ores, should provide an annual full-time employment of 15,000 by the mining companies, plus 700 in related railroad and power producing activities and 1000 in plant construction. Total capital investment in new plants should reach $1.5 billion by 1975 and $2 billion by 1990. These current estimates indicate that the conservative goals as set in 1964 for the year 1990 should actually be achieved by 1975 or 1980. BACKGROUND Various forecasts1,2,3 have been made of the future consumption and production of iron ores within the United States. The most recent of these is by Harrison,1 delivered at the American Mining Congress meeting in Las Vegas in October. His estimates reflect the latest iron ore developments on a world wide front as well as the accelerating trend toward pellets. Minnesota's Natural Resources council prepared a detailed report in 1964 outlining the various factors that affect the future of Minnesota's iron ore industry. It presented estimates predicated on the

Jan 1, 1967