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By Kwang-Tae Kim, Yong-Kun Choi, Jeong-Soo Chong, Yun-Jae Lee

An annex building at the former Agency for National Security Planning(NSP) complex located in downtown Seoul was demolished by progressive collapse method. This work was done as a part of efforts to restore the landscape of Namsan Mountain which lies in the Center of Seoul. The five-story reinforced concrete structure was razed in 5.5 seconds by the 29kg of high powered explosives which were placed in some 320 holes in the building with floor area of 2,577 m². The asbetos and all the other finishing materials in the building were removed before the demolition and the specially coated wrap minimized the spread of blasting dust. Seismic and air overpressure waves were monitored at 8 points, which were below safety limits and the continuous communication with neighborhood prevented any complaint.

Jan 1, 1998

[Ferro Alloys Producers Association The South Africa Institute of Mining and Metallurgy www.saimm.co.za Mintek www.mintek.co.za Eskom www.eskom.co.za ]

Jan 1, 2004

By Sergio Neves Monteiro

This work had as its objective the characterization of a waste material, steel slag, generated from an integrated steel plant, with a view to its recycling and incorporation into red ceramics fabrication. The characterization was performed in terms of chemical composition by X-ray fluorescence (XRF), particles size distribution, X-ray diffraction (XRD), thermal analysis (DTA/TG) and scanning electron microscopy (SEM). The results indicate that the steel slag presents high amount of Ca, Fe, Mg and Si. The weight loss of the steel slag at temperatures above 800oC is associated with calcium carbonate decomposition. The coarse particle size of the steel slag is inadequate for its direct recycling into red ceramic fabrication. It is necessary to screen or to grind the waste. As a possible solution, it is suggested that screening or grinding the steel slag to a convenient particle size distribution would allow its successful industrial incorporation into red ceramics products.

Jan 1, 2006

The Bibliographic Data Base contained in the present volume is the result of a literature search conducted as one task of the Bureau of Mines project concerned with research in borehole assay technology. The data base includes articles, symposia, books, corporate and government reports, patents, and other literature concerned with some aspect of borehole logging, from January 1969 through December 1975. Occasional updating to keep the data base current is anticipated. The remainder of the intro¬duction will be devoted to the explanation of the organization of each entry, along with the translation of terms and abbreviations used in the text. Each entry contains six sections. These include an ID code, a title, an author section, a source section, an abstract, and a descriptor section. The first item listed in an entry is the ID code. This serves to identify an entry. It consists of the first six characters of the first author's (or editor if no authors are involved) last name, along with the last two digits of the year of publication. A letter sometimes follows the year of publication to assure a unique alphanumeric code. For example, if an author named Wilson writes more than one piece of literature in a given year (for example, 1972), the ID code for the entries identifying these pieces of literature would be identical. Therefore, to allow for unique ID codes, the first piece would he identified as "WILSON 72,', the second piece as "WILSON 72A", the third "WILSON 72B", and so on.

Jan 1, 1976

By T. Nishimura, H. Kiyama, K. Wakimoto

Discussion on the load bearing capacity of ground and the stability of tunnel is presented. We derive a simplified solution of a circular lined-tunnel in an elastic ground. The solution results in a better understanding of characteristic curves. Use of DEM allows us to consider effects of possible yield of the overstressed zone around the tunnel and inherent discontinuity of ground on the curves. Diskussion auf der Last Tragfähigkeit Bodens und die Stabilität des Tunnels wird dargestellt. Wir leiten eine vereinfachte Lösung eines kreisförmigen Ausbautunnels in einem elastischen Boden ab. Die Lösung ergibt ein besseres Verständnis der Kennlinien. Um Gebrauch DEM erlaubt uns, zu betrachten Effekte des möglichen Ergebnisses der überbetonten Zone den Tunnel und zugehörige Unstimmigkeit des Bodens auf den Kurven. La discussion sur la portance de charge de la terre et de la stabilité du tunnel est présentée. Nous dérivons une solution simplifiée d'un revêtement-tunnel circulaire dans une terre élastique. La solution a comme conséquence une meilleure compréhension des courbes caractéristiques. L'utilisation de DEM nous permet de considérer des effets du rendement possible de la zone surchargée autour du tunnel et de la discontinuité inhérente de la terre sur les courbes.

Jan 1, 2003

By Andreas Prucker

The Greater Vancouver Water District (GVWD) is currently constructing the largest water treatment plant in Canada. As part of this treatment scheme twin water transfer tunnels are being constructed. Work commenced with the 11 m diameter, 185 m deep Seymour Shaft which was excavated by drill and blast using a mobile crane for hoisting. The Seymour Shaft is the first large diameter shaft that has been sunk in Western Canada in recent years. The operational aspects associated with the hoisting, the drill-blast-support cycle and water control in the shaft are the focus of this paper.

Jan 1, 2008

By J. Arzuúa, U. Castro-Filgueira, L. R. Alejano, F. Malan

"Pillar design for underground mining is typically done using empirical formulae or numerical modelling. Practical experience and recent literature, nevertheless, illustrate the shortcomings of these design approaches. Ongoing monitoring of pillars is therefore recommended to minimize the risk associated with these designs.In a mine where a large number of pillars are cut, different pillar strengths can be expected owing to variations in rock mass strength from area to area. This problem is compounded by the fact that in mining environments the pillars are not always cut according to the prescribed dimensions. Although the original design using either empirical methods or modelling may predict stable pillars, unstable pillars will be encountered in reality. Very conservative designs with large factors of safety may circumvent this problem, but this approach is uneconomical.A possible solution to localized stability problems may be to enhance the strength of a few unstable pillars. It may even be hypothesized that reinforcing a few critical pillars may prevent ‘pillar runs’ on a much larger scale. Rockbolting, strapping of pillars, and pillar shotcreting have occasionally been used in the past as possible solutions. It appears that these have not been successful in all cases and large collapses have occurred in spite of the pillar remedial work.The authors investigated the strapping of pillars by conducting laboratory tests on cabled rock specimens. The results were qualitatively compared to actual attempts of pillar reinforcement available in the literature, as well as additional observations in an old haematite roomand- pillar mine in Spain. Based on these results, the value of steel cabling and mesh wrapped around pillars to improve stability is demonstrated. Some cases where this approach will not be successful are also discussed."

Jan 1, 2017

By Stephen P. Signer, John L. Lewis

This paper presents the results of a case study conducted in a two-entry gateroad in a coal mine where excessive roof deformation and bolt loading resulted in failure of many roof supports. The instruments consisted of 16 fully grouted, strain-gaged resin bolts, load cells on both full and partially grouted cable bolts, and vertical deflection multipoint extensometers. These instruments were installed on-cycle to measure loading on bolts in an existing support pattern and to determine if cable bolts could be used to improve roof stability. Results showed significant amounts of movement within the bolted zone. In some cases, these movements were enough to load the supports past their ultimate strength. Geology appeared to be a significant factor in localized roof degradation; that is, a very weak rock layer in the immediate roof overlain by a very strong rock layer contributed to the development of shear planes. Only one instrumented bolt had a maximum strain of less than 2,000 microstrain, which was the yield point of the steel. The average maximum strain on all bolts was 20,000 microstrain. However, electrical continuity to many gages was lost and a pattern was noted that would indicate possible bolt failure. Wire mesh and concrete cans installed as secondary support performed very effectively.

By G. T. Lineberry, W. J. Wiehagen

A Paradigm Shift As market economists, mine managers are interested in "staying in business" and even "prospering." Bottom-line results are the "order of the day." Concern for bottom-line results invokes questions such as: How much was produced? At what cost? And, was anyone injured? While these questions will always carry everyday emphasis at the mine, they are fundamentally lacking in that they often appear, especially to lower levels of management and to the production worker, as preeminent concerns. Driven by market economics, many organizations have decentralized, outsourced, downsized, restructured, and formed new coalitions. Investments in new technology and concentration on productivity have been part and parcel with these changes, contributing to improvements in both safety and efficiency. A reason for (and, perhaps a result of) these improvements has been the development of a highly experienced and flexible work force. These changes in mining present an interesting opportunity to modify a few paradigms about work life in general, and perhaps a few paradigms about how we invest in the miner, in particular. Studying these issues now might offer some interesting opportunities for the future, as the foundations for the next generation of mine workers are laid. With the average "experienced" U.S. miner five to fifteen years from retirement, perhaps a key determinant of future success in the world market might be how well we make the transition from today's work force to the work force of tomorrow. We can ill afford to wait a few more years to tap into the special knowledge residing within a veteran mining work force. The WCPM work Crew Performance Model, see pp. ) is one approach to defining, capturing, and transferring this expertise.

By M. C. Fuerstenau

Collophane, cryptocrystalline fluor-apatite, is examined as a substrate for plant water and wastewater remediation. The attenuation of Fe3+, Fe2+, Hg2+, Pb2+, and Cd2+ is presented as a function of metal ion concentration, amount of collophane, initial pH and conditioning time. TCLP results for Pb2+contaminated collophane are presented. Mechanisms of adsorption for divalent and trivalent species are suggested.

Jan 1, 2001

By Onur Golbası, Berk Gokce

Investment decisions in the mining industry are complicated by sector-specific uncertainties. This study presents a multi-submodule system dynamics model to capture the dynamic complexities of decision-making across mineral property development stages. The model includes five interconnected subsystems: valuation, production, growth strategy, demand, and finance. Developed through system decomposition, expert input, and literature, the model is tested on a hypothetical copper mine with 850 ktpa capacity and 1% cu grade. Simulated over five years with quarterly steps, it estimates an enterprise value of $78.9 million and a target growth rate of 11.2%. Results highlight the significant effects of operating costs, capital policies, and inflation on free cash flow, and the critical role of mineral reserves in sustaining growth. This model supports strategic investment analysis across different minerals and development phases, offering mining investors a robust tool for optimizing decisions.

Feb 22, 2026

By Emma Arakelova

An increase in concentration of a Zn-containing volatile complex for synthesis of ZnO films was investigated when processing their target by ultraviolet radiation emitted by mercury lamp. The experiments were carried out using a flow-type quartz reactor. ZnO tableted target was preliminarily irradiated during 2 to 7 hours. H2O2 (98%) vapor at 25Pa passed through the reactor with ZnO target at 373K. As substrate material, five subsequent quartz cylinders were used at 423K. The experiment lasts 4 hours. H2O2 decomposition on ZnO surface was accompanied by formation of a Zn-containing volatile complex which passed in gas phase and decomposed on the substrates with isolation of final ZnO. The concentration of the Zn-containing volatile complex (N) in gas phase increases with UV pre-irradiation time (t) (without irradiation N = 1.05 1011 particles/cm3; after t=2 hours, N = 5.19 1011 particles/cm3, after t=4 hours, N = 9.95 1011 particles/cm3; after t=7 hours, N = 1.86 1012 particles/cm3.

Jan 1, 2006

By J. R. Thoenen

In June 1929 the Bureau of Mines issued a 13-page information circular entitled "Mineral Wool," which was one of the first publications to present to the public Rome technical aspects of the mineral-wool industry. Since then several articles on the subject have appeared in the technical press as well as in publications of State organizations. Inquiries for information on mineral wool have continued to be received by the Bureau of Mines in large number, and in 1935 it was decided to make a field survey of the plants then producing and to collect therefrom technical data to be compiled in a paper for nubile distribution. With the cooperation of the industry, this survey was made, and Information Circular 6984, Mineral Wool, was published in January 1930. The issue was exhausted after a few months, and requests for copies continued to come to the Bureau. As opportunity arose, further field studies were made in American as well as Canadian plants. The present circular contains the essential information in Information Circular 6994 together with date from later field studies.

Jan 1, 1939

By Timothy C. Siegel

A piled raft refers to a shallow foundation that is structurally connected to the piles, while composite ground refers to a soil-pile matrix where the piles are not structurally connected. The design objectives for both a piled raft and composite ground are (excluding special considerations such as expansive soil): (1) to provide a sufficient ultimate resistance and (2) to distribute the load into the soil-pile matrix so that the settlement experienced by the shallow foundation is within tolerable limits. A simplified model is proposed for a shallow foundation on composite ground where the foundation settlement is estimated as the sum of the downward movement of the piles plus the downward movement of the shallow foundation relative to the pile head. The proposed simplified model is applied using conventional geotechnical analyses for two hypothetical examples of shallow foundations undergoing compression settlement.

Jan 1, 2011

By Stephen C. Tadolini, Yunqing Zhang, Thomas M. Barczak

Standing crib supports have been applied in underground mining programs to resist large roof movements and sustain high-loads. The strength and deformation capability of these systems has been documented under both laboratory and field conditions. The parameter that has not been examined and is not well understood is the effect that a crib or other types of standing support has on the primary and secondary bolting systems. A crib support system with low system stiffness may allow large amounts of closure and deformation and cause the bolting systems to yield or even fail. Conversely, cribs or standing support that are too stiff may experience brittle or buckling failures, negating the advantage of the intrinsic supports previously installed. Utilizing a combination of field measurements and 3-dimensional finite element modeling techniques, the relationship between system stiffness and the subsequent performance of the installed bolting system is evaluated. Additionally, a simple method for calculating the combined system stiffness for standing supports, when using materials with different strengths such as steel, concrete, wood, etc., is presented.

By Junior Santos

Kinross Paracatu started the operation of the new gold processing plant in the end of 2008, being composed by one SAG mill and two ball mills. During the first year of operation the plant had several problems related to stability and throughput capacity, mainly due to low grinding efficiency of the ball mills. In this period many actions were taken to maximize the throughput rate. Among the actions are reducing the size of balls in the mills, increasing the ball charge in the SAG mill, changing cyclone configuration and return of circulating load to SAG mill. With better stability of the circuit, the second stage of improvements has begun with the objective of increasing throughput rate and also reducing operation costs. Among the actions are the optimization of ball charge in the mills and a better operational control of cyclone parts. After two years of operation was obtained a significant increase in plant capacity, but still requires the addition of a third ball mill in order to maximize the use of SAG mill, which has spare capacity.

Jan 1, 2012

By Paul Wellman

A computer program is presented that may be used to calculate the bare equipment cost of the major processing units for any hot potassium carbonate gas purification system. The program is designed such that, with only minor modifications, it could be used with a variety of computer systems.

Jan 1, 1968

By Avery H. Reed

RECORD production of marble, kaolin, scrap mica, and talc high-lighted the mineral industry of Alabama in 1962. Among the States, Alabama ranked second in scrap mica, third in the production of bauxite and native asphalt, and fifth in iron ore. The mineral industry of Alabama was dominated by mining and processing of coal and iron ore, and the manufacture of cement, which together comprised 73 percent of the total value of production, compared with 72 percent in 1961. Other important industries were the production of crude petroleum, and stone quarrying. Leading companies were Tennessee Coal & Iron, Southern Cement Co., Southeastern Electric Generating Co., Alabama By-Products Corp., and U.S. Pipe & Foundry Co.

Jan 1, 1963

By R. Luhrman, E. Christ, B. Gores, S. Fischer, E. Johanning

North American railroad locomotive operators (engineers and conductors) are exposed to multi-axis vibration and shocks (1, 2). A recent epidemiological survey showed a prevalence of serious type of neck and lower back disorders nearly double that of a control group (3). Ergonomic working conditions are important co-factors in a vibration and shock exposure risk assessment (4, 5). The goal of this study is to illustrate typical work stations (cabs and seats) in US/Canadian type locomotives and assess shock related exposure risk by calculations of the new proposed shock risk indicators according to the new ISO 2631-5 (2004) (6). Methods Locomotive cab and seat inspections were conducted and operators’ activities were assessed by a trained observer. Field measurements (n=50) were obtained during normal revue service following generally accepted guidelines (ISO 2631 (1)). A sub-sample of n=20 locomotives were selected for the calculation of proposed shock indicators (ISO 2631 (5)). Results There has been little change in basic locomotive cab and seat design in the U.S.. Two locomotive cab design concepts are used: the Association of American Railroad (AAR) Control Stand and in newer series wide-body locomotives the “Control Consol” (Figures 1-2), with varying seating conditions, but frequently subjecting the operator to an awkward body posture in addition to the vibration and shock exposure. [ ]

Jan 6, 2006

By Susan Jacob

The heat of fusion of silver was measured using high temperature differential scanning calorimetry (HTDSC). Heating rate, sample mass, calibration standard and cover gas flow rate were varied to determine their impact on instrument accuracy and reproducibility. Good reproducibility was achieved in most of the runs. Accuracy was not satisfactory in most of the runs, though three runs gave results within 1.7%, 3.3% and 3.5% of the literature value, within the acceptable limits. A larger mass and higher heating rate tend to generate more accurate results.

Jan 1, 2006