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By C. E. Ells, A. Sawatzky

The effect of neutron irradiation on tensile properties of the Zr-2.5 wt pet Nb-0.5 wt pet Cu alloy has been evaluated for integrated neutron fluxes up to 3 x 1020 n per sq cm (E > 1 Mev). Specimen temperature during irradiation was normally 300°C. The material was studied both in annealed and in quenched and aged conditions. When the alloy (fab-ricatedfrom sponge zirconium) is quenched from a temperature =40°C below the a + ß/ß transformation and aged 6 hr at 535oC, neutron irradiation up to the maximum studied has little effect 071 reduction in area, although there is a drop in uniform elongation and the yield strength is increased by = 25 pct. Conversely, irradiation of the alloy in an annealed condition can result in much greater changes in properties, with yield-strength increases of up to 200 pet. The dose dependence of irradiation hardening obeys the saturation equntion proposed by Makin and Minter to explain hardening in copper and nickel: Act = C[1 - exp(-Døt)/1/2 A rnodel is proposed to explain the effect of niobium content and metallurgical condition on irradiatiotz behavior. THE Zr-Nb alloys form a class of material susceptible to marked strengthening by quench and age heat treatment. With niobium concentrations as low as 2.5 wt pet, strengths can be developed which are double those of annealed zircaloy-2.1 Since the neutron-capture cross section of the Zr-2.5 wt pet Nb alloy is nearly identical to that of Zircaloy-2, significant gains in power-reactor neutron economy could be obtained by replacing stressed in-reactor components of Zircaloy-2 with the heat-treated Zr-Nb alloy. When the solution heat-treatment temperature is in the high (a + ß) phase, then the tensile properties of the quenched (and aged at 500°C) material have been shown to be relatively insensitive to neutron irradiation.1-3 Addition of small quantities of copper to the binary Zr-2.5 wt pet Nb alloy gives a useful reduction to the corrosion rate in air and carbon di- oxide,&apos; and a ternary alloy of composition Zr-2.5 wt pet Nb-0.5 wt pet Cu was chosen for one component in the Douglas Point Reactor. This application utilizes both the corrosion resistance to a moist air-carbon dioxide environment and the strength developed by a quench and age heat treatment. By suitable choice of solution heat treatment and aging temperatures, tensile properties of the ternary alloy can be made nearly identical to those considered as optimum for the binary alloy. One effect of the copper addition, however, is to give marked changes in the aging kinetics of the alloy.&apos; For this reason, it appeared that neutron irradiation might promote overaging in the ternary alloy, particularly at the elevated service temperature (=300°C). This paper describes the effect of neutron irradiation on the tensile behavior of the Zr-2.5 wt pet Nb-0.5 wt pet Cu alloy in several metallurgical conditions pertinent to its use as a reactor material. The metallurgical conditions included those for which aging occurs in the unirradiated material, and fully annealed conditions for which a higher degree of thermal stability could be expected. 1) EXPERIMENTAL Two batches of alloy were used, both made from sponge zirconium. The fabricator&apos;s analysis of principle constituents showed no significant difference between the two batches, Table I. The rod material was rolled to 1.5 in. diam, and then swaged to final sizes of 0.5 to 0.375 in. diam at nominal temperatures of 785" and 625°C for the AM and AS batches, respectively. Subsequent hydrogen analyses at CRNL confirmed that the hydrogen concentration of the as-received rod was indeed <20 ppm. However, it was found that the (a + ß)/ß transus for the AM material was approximately 25°C lower than that of the AS material, indicating rather more difference in oxygen concentration than given in Table I. Except for a small difference in yield-point behavior, the tensile prop-

Jan 1, 1965

By I. B. Lambert

The guide has been developed by officials from resources and environment agencies in the Australian Government and the South Australian and Northern Territory Governments. It elaborates on the Australian Government?s policy that new uranium mines are to be approved subject to world best practice environmental and safety standards. The guide outlines the best practice principles and approaches that apply generally to mining in Australia, before giving more detailed consideration to best practice environmental protection and regulation for ISR mining.

Aug 1, 2010

"In 2008, the Committee for Mineral Reserves and International Reporting Standards (CRIRSCO) and the Russian State Commission on Mineral Reserves (GKZ) entered into an agreement leading towards harmonization of Russian and international minerals reporting systems. The purpose of the protocol is to define an agreed method by which mineral resources and reserves, reported by companies in Russia according to the current Russian classification system, can be expressed in terms that are comparable to the CRIRSCO reporting codes in Russia and elsewhere."

Jan 1, 2003

By Osvaldo A. Bascur

Business Challenges ? Many Versions of the Truth ? Lack of Enterprise Visibility (Transparency) ? Limited Communication & Collaboration ? Complex Implementation & Maintenance of software ? End user ease of use of information applications ? Responsive to change ? Access to timely information ? Secure computing ? Maturing Workforce Real time Portal - First of All ? Why Move to a Portal - Portals Recaptures the Business User - Broader Scope - Easy Navigation, World Standard - Features of a Portal - User Profile - Delegation (Secure Delegation of Admin Authority e.g. portal\pat) - Single Sign-On ? HUGE

May 1, 2004

By B. S. Pierce

The National Coal Resource Assessment – 2000 project was a multi-year effort by the U.S. Geological Survey to identify, characterize, and assess the coal resources that will supply a major part of the Nation’s energy needs during the 21st century. The purpose of the USGS National Coal Resource Assessment (NCRA) was to (1) digitally assess selected coal beds and zones that will be the most important in the next few decades, (2) create publically available stratigraphic, geochemical, and geographic information system (GIS) databases to answer a variety of questions of importance to government, industry and public decision makers, and (3) provide interpretive geologic and geochemical information for the primary coal resources of the Nation. Five priority regions were assessed: the Appalachian Basin, Illinois Basin, Gulf Coast, Illinois Basin, and Northern Rocky Mountains and Great Plains. The NCRA was a cooperative effort between the USGS and a number of State geological surveys in these coal-bearing regions. A study of coal resources on Federal lands was also conducted. Adequate energy supplies and the efficient use of those supplies are critical to the economic well being of a country. Affordable and reliable coal supplies are essential to the interests of our national and local policymakers. Policy makers require a range of information on the energy supply, as well as the economic and environmental issues associated with that energy source and its use. Formulation of an effective national energy policy and development of energy resources requires that we understand the geology, distribution, quality, and size of the national energy endowment.

Jan 1, 2001

By W. C. Lacy

Traditionally Australia has been a leader in underground mining methods with world standards being established at Mount Isa, Broken Hill, Kalgoorlie, and Mount Lyell. With decline in higher-grade reserves and discovery of a multitude of near-surface oxide gold de-posits attention has shifted to bulk mining of low-grade gold ores by open pit methods, heap leaching and activated carbon recovery of gold values. The paper examines historical change in mining philosophy and the economic effects of isolation.

Jan 1, 1993

By K. E. Stanfield

The oil yields of sections of Green River oil shale in Colorado, Utah, and Wyoming are presented as part of a continuing project to determine oil-shale reserves in the United States. Oil-yield logs, based upon analyses obtained from 1945 through 1952, are presented to show the thickness and richness of 202 sections of Green River oil shale. The logs are based on analyses of approximately 20,500 samples, representing 179,000 feet of shale, which were made by the Bureau of Mines, and upon analyses, representing approximately 26,000 feet of shale, which were made by other agencies. The samples consisted of cores from a Bureau of Mines coring program in U. S. Naval Oil-Shale Reserve 1, Garfield County, Colo., and cores, drill cuttings, and channel samples provided by other agencies, chiefly oil companies. Most of the samples of oil shale from Utah and Wyoming were derived from oil-well drilling operations. As a result, the oil-shale sections were widely scattered and were not extensive or reliable enough to be representative of the significant deposits of Green River oil shale in these States. The oil-shale sections for Colorado, however, were more comprehensive, and a number of the sections were used in a previous report as a basis for estimating oil-shale reserves in Colorado. The present report does not give estimates of oil-shale reserves but is limited to presentation of oil-shale analyses that may be used for future reserve estimates. Other sections of Green River oil shale are being analyzed, and the results will be published in subsequent reports.

Jan 1, 1954

By N. Sahay

Improvement in work place environment by conventional methods viz., installation of higher capacity fan, fans in parallel operation or booster fan is a risky proposition in many coal mines in India because of difficult geo-mining condition such as shallow depth, multi seam workings having thin parting and inter connected goaves one above the other. The situation is further worsened if the mines have fire affected sealed off area connected to different ventilation circuits. On many occasions circulation of more air quantity by increasing fan pressure have resulted in initiation of spontaneous heating. To address these problems, authors have made some improvement in conventional Dynamic Balancing of Pressure Technique and worked out few ventilation schemes which are aimed for neutralization of pressure differential across sealed off area at the same time having improvement in ventilation in the mine. The excess pressure differential across sealed off area is mainly caused by introduction of higher capacity fan. Similar situation prevailed in one of the mines of Jharia Coalfield, India. The problem was solved by application of the above technique. In this paper, brief description of the technique, the problem in the mine, results of investigation, computer simulation studies of various schemes and methodology adopted for implementation of the technique in the mine have been discussed in some detail. Keywords: Dynamic Balancing of Pressure Technique, Spontaneous heating, Work place environment.

Jan 1, 2003

By Fred C. Turin, Sean Gallagher, Kim M. Cornelius, William J. Wiehagen

An important part of initiating a site-wide ergonomics evaluation process is prioritizing jobs to be analyzed. While injury data is important, other factors such as worker discomfort and physical exertion requirements, should be considered. This paper describes the use of four sources of data (injury records, the Nordic Standardized Musculoskeletal Questionnaire, supervisor interviews, and management concerns) to prioritize jobs for ergonomic analysis. The approach described integrates the four sources using a decision matrix to prioritize jobs for ergonomics analysis.

By Ian Mcgaffin

P.T. Kellan Equatorial Mining (KEM) is an Indonesian incorporated company owned 90% by CRA Limited of Australia and 10% by PT. Harita Jayaraya of Indonesia. The Kelian gold mine first commenced production in January 1992 and has produced in excess of 21 tonne of gold (675,000 oz) in its first 18 months of operation. The operation is a large tonnage low grade deposit that accepts a low gold recovery by industry standards due to the partially refractory nature of the orebody.

Jan 1, 1993

By C Hunter, K Fedak, J P. Todoeschuck

"Perimeter wall control has a direct effect on the overall grade of any underground miningoperation. Mine management at INCO's Birchtree Mine in Thompson, Manitoba requiresmaximum perimeter wall control to meet high safety standards and to maximize nickel orerecovery. If footwall or hanging wall contacts are damaged by over_blasting, the ore maybe greatly diluted, mine productivity may be reduced and safety problems can arise.Excessive or poorly distributed explosive energy is a major cause of damage to the hostwall rock."

Jan 1, 1993

By C. H. Burgess

ON June 5, 1947, Secretary of State George C. Marshall in a speech at Harvard University outlined a plan for the economic recovery of Europe. The plan contemplated that the United States should provide assistance which would enable the European nations better to help themselves and to help each other to reconstitute from their war-torn lands conditions which would make possible decent standards of living. The Foreign Assistance Act of 1948 was passed in April of that year, and established the Eco-

Jan 10, 1950

By Dalzell R. W

A Conveyor Belt Fire Test Program was initiated in 1985 by the Approval and Certification Center (A&CC), Mine Safety and Health Administration (MSHA), U.S. Department of Labor. The purpose was to evaluate the effect of entry air velocities on the burning properties of mine conveyor belts and assess fire test data from large- and small-scale tests. Belts meeting the fire-resistant standards of MSHA and agencies of other countries were tested in small- and large- scale fire tests.

Jan 1, 1988

By John M. Karpinski, David S. Cahn

For many years the green and dry compressive strengths of pellets have been considered as possible criteria of pellet performance during induration. Little attention, however, has been given to standardizing the unfired pellet compressive strength test or to determining the characteristics of this test. The purpose of this study was to compare the constant deformation rate test with constant loading rate tests. In addition, the dependence of these tests on such pellet properties as size and weight was to be investigated.

Jan 7, 1969

By R. Hogg, A. C. Maffei, D. T. Ray

Based on standard population balance models for agglomeration and size reduction processes, a simplified model has been developed to describe simultaneous growth and breakage in the flocculation of agitated suspensions. The results of semi-batch flocculation tests have been used for estimation of the model parameters and empirical relationships have been obtained to describe the effects of process variables and to establish scale-up criteria. Application of the model to the design, operation and control of continuous flocculation processes is discussed.

Jan 1, 1990

By Kal V. S. Sastry

Mathematical and expert system models are being used extensively for mineral process engineering; nevertheless, standardized methodologies for their computer implementation do not exist. In meeting this need, this paper introduces the concept of a process software model, or more specifically an object-oriented software model, and presents a detailed methodology for its development involving software model specification and development. These software models provide a formal basis for the subsequent design and construction of software objects corresponding to the real world process objects.

Jan 1, 1995

By Patricia Dillon

EHS Management Standards Communication and Reporting (8) ! Establish processes for internal and external communications ! Designate responsibilities for communication with COI ! Report as defined by senior management ! Report annually to employees, shareholders, COI on EHS and social performance Community Rights and Public Consultation (9) !Identify COI?s and establish process to hear concerns !Acknowledge and respond to complaints !Support local communities !Plan for closure and conduct public consultation !New projects include identification of COI?s, concerns to be considered in design

May 1, 2004

By Robert W. Hunt

In 1888 the writer had the honor of submitting to the Institute a paper on " Steel Rails and Specifications for their Manufacture."* In his judgment the specifications were sufficient for "that day and generation." In that paper I said: &apos;&apos; The first duty falls upon the railroad engineer in designing his section. If that is bad, the steel-maker will be heavily handicapped in trying to furnish a satisfactory rail. I suppose it is hopeless to expect the adoption of standard sections."

Jan 1, 1896

By Dominique François-Bongarçon

A new method for open-pit design has been devised by G. MATHERON and the writers: it replaces the search for an optimum contour by the determination of a parametrizing function. The isovalue curves of this function give the optimum pit design corresponding to varying economic parameters; The method is described and indications are given about the corresponding program. Simulated data have been processed by the program and by a standard program using LERCES-GROSSMAN graphical method: the comparative results are described.

Jan 1, 1977

By Kwang-suk You

This paper describes the characteristics of electric arc furnace slag (EAF slag) as an aggregate of concrete along with the chemical composition, leaching concentration of heavy metals, the soundness of EAF slag and compressive strength of mortar with 20% and 50% replacements of sand. The results showed that leaching of heavy metals and soundness of EAF slag satisfied Korean environmental limit and Korean Industrial Standard for aggregates. The compressive strength of mortar increased as the replacement ratio of EAF slag for sand increased.

Jan 1, 2006