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By Bassam Kattaa

"Abstract - A heavy mineral survey of beach and dune sands including geochemical analysis for trace elements was undertaken to evaluate the economic potential of the sands and to understand the nature and distribution of the heavy minerals relative to potential source rocks. Results indicate that heavy minerals are generally derived from outcropping volcanic rocks that comprise a proportion of the hinterland in the south part of our survey area. The most abundant minerals are magnetite and pyroxene. The morphologies of the heavy mineral grains are angular to subangular, suggesting that they were transported short distances from the source rocks. Factors controlling heavy mineral distributions include wave and wind action, proximity to provenance, the fluvial drainage network, and longshore currrents.The most economically important mineral is ilmenite. Zircon and rutile concentrations are relatively minor and thus have lower economic potential."

Jan 1, 2002

The 118th meeting of the Institute was under the auspices of the Institute of Metals Division and the Iron and Steel Section, and was held at Milwaukee, Wis. The opening session was a joint meeting with the American Foundrymen's Association and the American Malleable Castings Association, and was presided over by Benjamin D. Fuller, President of the American Foundrymen's Association. At this time Hon. Emanuel

Jan 12, 1918

By Luis Elu, Andy Bolland, Jack Simmons

The gold refinery at Barrick Goldstrike Mines has increased production to more than 2,000,000 ounces poured per year while reducing the labor requirement. Safety and health has not been compromised with this increased production and in fact incident rates and exposures have reduced over the past five years. Streamlining procedures, improving ergonomics and the wise use of unique innovations has accomplished this significant achievement.

Jan 1, 1998

By Frank L. Nason

During the months of June and July of the present year, the writer made a special geological survey of the mining property of Messrs. Cooper and Hewitt, at Ringwood, New Jersey. Some of the results of this survey are presented to the society through the courtesy of Hon. Abram 8. Hewitt.

Jan 1, 1895

By Betty L. Gibbs

Computer software for mining applications has been in development since before 1970. These packages cover tasks from exploration data management through final reclamation planning. These programs were originally written in Fortran and have evolved into colorful, user-friendly packages. Programs that produced printed symbol maps now show color, three-dimensional image of an ore deposit on a computer screen. Pictures can be rotated and looked at it from all directions and layers can be peeled off to show other parts of a model. Computer users have also evolved. In the early Fortran days, users had to learn computer operating systems, have someone punch data cards, set up run files and wait a day or so to find out if there was one little mistake somewhere that caused the program not to run. With today's technology, users sit at their desks in the office, key in some data, read other data from digital files and build a model within days, rather than weeks or months.

Jan 1, 1999

By Yoshihiro Moriyama, Toshihiro Okitsu, Ryouichi Banno

The fracturing composition using the gas pressure generated by the thermit decomposition reaction gives the following performances.

Jan 1, 1995

By John C. Machisak

INJURY DATA and experience at coal mines in the United States for 1957 are presented in this bulletin under the following general sections: (A) General injury experience: Tables 1-6: Current data on number of fatal and nonfatal injuries, frequency and severity rates, and average severity. (B) Selected injury experience: Tables 7-36: Current data on causes of injuries, distribution of injuries by part of body injured, days of disability, extent of hand and machine loading, experience by employ¬ment and production groups, and various other operating factors and physical conditions related to the occurrence of injuries at the Nation's coal mines. (C) Injury experience, by States: Tables 37-41: Data on injuries, injury rates, employment, causes of injuries, and severity rates. (D) Major disasters: Table 42: Data on major disasters from 1948 to 1957. A major disaster is defined as a single accident in which, or as a result of which, five persons or more are killed instantly or die at any time thereafter. (E) Historical coal-mine-fatality experience: Tables 43-47: Data on fatalities and their causes at bituminous-coal, lignite, and anthracite mines from the earliest records through 1957.

Jan 1, 1960

By Yajie Wang

Traditionally, roof falls are usually attributed to bad roof strata and high vertical stress related to the overburden depth. However, roof falls under shallow overburden depth are oflen caused by a high horizontal stress field. Recent studies have proven that the high horizontal stress field, if existing, plays a major role in roof stability. Also the roof conditions are related to the entry diredions under a horizontal stress field. Questions are: How to orient the entry to a favorable direction to prevent the roof falls? If the entry cannot be oriented, how to support it? Through a case study in mine A, this paper analyzes the horizontal stress effect on roof stability. The guideline for the entry orientation is given based on the results of analysis. Additionally, suggestions are made for those entries that cannot be oriented to a favorable direction.

Jan 1, 1998

By G. M. Schwartz, J. N. Gundersen

John W. Gruner (Professor Emeritus, College of Science, Literature, and the Arts, Dept. of Geology, University of Minnesota, Minneapolis) — It is surprising that two men as well acquainted with the taconite rocks of the Mesabi District as Drs. J. N. Gundersen and G. M. Schwartz should have concluded that the taconite of the Eastern Mesabi before the intrusion of the Duluth gabbro consisted largely of quartz and magnetite. These minerals were "locally reconstituted" into "a wide variety of silicate mineral assemblages" by the gabbro. It is well known, of course, that the silicate mineralogy of the Eastern Mesabi ('about 14 miles in length) is quite different from that of the Main Mesabi which is over 60 miles long. The change from one to the other is abrupt and cannot be attributed to any other cause than the thermal effects of the gabbro. Are we to assume or believe that the taconite of the Eastern Mesabi was radically different from that of the Main range before the gabbro metamorphosed it?

Jan 1, 1962

By M. J. King, W. K. B. Loftus, H. S. Simpson

SYNOPSIS The history of the early diamond fields and primitive methods of diamond recovery are traced, giving a brief description of the improvements made in final diamond recovery processes and techniques up to the present day. In particular the emphasis is on the effect of improved equipment in reducing final hand sorting time and labour, better security and greater recovery of fine diamonds.

By C J. N Wilson

The central Taupo Volcanic Zone is a region of intense Quaternary silicic volcanism accompanying rapid crustal extension. Modem central TVZ is the most frequently active and productive silicic volcanic system on Earth, erupting rhyolite at c.0.28 m3 s-1. The rhyolites show no major compositional changes with time, but the total extent of magma chamber zonation has changed with the advent of rifting and crustal extension at c.0.7 Ma. At least 34 caldera-forming ignimbrite eruptions have formed a complex sequence of relatively short-lived, nested and/or overlapping volcanic centres in central TVZ. Taupo contrasts with other large silicic magmatic systems in the exceptionally high frequency, but small size, of caldera forming eruptions. This contrast reflects the thin, rifted nature of the TVZ crust that precludes the development of long term magmatic cycles at Taupo. Within central TVZ, non-rhyolitic compositions have been erupted apparently irregularly in time and space; in particular there is no evidence for a geographic separation of basalts from andesites. TVZ is a rifted arc, but its segmented nature, high thermal flux and voluminous rhyolitic volcanism make it unique on Earth.

Jan 1, 1995

By J. C. R. van Schoor

In this study the applicability of a batch press to predict the energy consumption and particle size distributions for medium-pressure roller presses was investigated. The relationships between energy consumption, feed size and product size are discussed with reference to Hukki?s interpretation of Bond?s and Rittinger?s laws, as well as the particle size parameter used. It was found that the comminution laws have limited utility for the characterization of the performance of the medium-pressure roller crushers or the batch press used, and also depend on the particle size distribution indicator used. It was also found that the batch press is not a suitable simulator for medium-pressure roller mills as it was notable to predict the energy requirements, or to predict the size distributions that would be obtained for the ores evaluated.

Jan 1, 2012

By S. Al-Hassan

The deposit has been exploited for Mn oxide and carbonate since 1916. Known reserves of MnO, however, are almost depleted and the survival of the mine will depend on the exploitation of the carbonate. Kriging, inverse distance weighting (IDW) and cross-sectional methods have been applied to the evaluation of the carbonate resources and reconciliation of the estimates obtained shows that kriging and IDW give almost identical block values. A comparison using conditional probability indicates that there is virtually no difference between the global reserve estimates derived from the cross-sectional and kriging methods. The physical causes of these similarities are highlighted and the problems of dealing with multimodal distributions are discussed together with the difficulties of semi-variogram modelling

Jun 19, 1905

By C. S. Barrett, P. Coheur

AXnealing twins are common in the microstructure of copper that has been rolled and recrystallized. In such samples it follows that a twin relationship should exist between components of the re-crystallization texture,' and several examples of this have been reported. For example, twin relationships have been found in recrystallized electrolytic copper sheet, as indicated in Fig. I, from a paper by Coheur and Lejeune.2 In this pole figure the cube texture (100) [001] is indicated by the hollow squares in the lower half of the figure (the pole figure for 200 reflections) and in the upper, (III), part of the figure. The texture contains, in addition to this orientation, the first-order twins of it, shown in the figure by the filled triangles. This orientation relation has been suggested by others also, under certain annealing conditions,3'4 although pole figures have not been published to confirm it. Some orientations in recrystallized sheets are identical with their twins, because of the symmetry elements of the texture— this is true, for example, with the (113) [ZII] texture so commonly reported for brass—hence it appears impossible in such samples to decide whether the twin relationships result from twinning or merely from the symmetry of the deformation process. The present investigation of a commercial copper strip seems to yield an example in which annealing twins account unambiguously for the principal orientations present. It proves to be a case, also, for which the recrystallization texture cannot be viewed as derived from the deformation texture by a first or second-order twinning mechanism. Materials and Methods The samples investigated were of secondary copper (melted in belgium) to which 0.19 per cent iron had been added to raise the recrystallization temperature. How much the orientation characteristics of this metal can be ascribed to the iron content and how much to other impurities or to melting and pouring practice have not been investigated.* The rolling was done in one direction only, on a mill with rolls of about 20-cm diameter. A strip I. cm wide was reduced from 5 mm thickness to 0.05 mm by several cold passes at commercial speeds. The samples cut from this 99 per cent reduced strip were X-rayed throughout their entire thickness. A pole figure made soon after rolling and annealing was identical, within experimental error, with one that was made when a two-year interval occurred between rolling and annealing. X-ray patterns were made on a camera2 that traversed

Jan 1, 1947

By C. S. Barrett, P. Coheur

AXnealing twins are common in the microstructure of copper that has been rolled and recrystallized. In such samples it follows that a twin relationship should exist between components of the re-crystallization texture,' and several examples of this have been reported. For example, twin relationships have been found in recrystallized electrolytic copper sheet, as indicated in Fig. I, from a paper by Coheur and Lejeune.2 In this pole figure the cube texture (100) [001] is indicated by the hollow squares in the lower half of the figure (the pole figure for 200 reflections) and in the upper, (III), part of the figure. The texture contains, in addition to this orientation, the first-order twins of it, shown in the figure by the filled triangles. This orientation relation has been suggested by others also, under certain annealing conditions,3'4 although pole figures have not been published to confirm it. Some orientations in recrystallized sheets are identical with their twins, because of the symmetry elements of the texture— this is true, for example, with the (113) [ZII] texture so commonly reported for brass—hence it appears impossible in such samples to decide whether the twin relationships result from twinning or merely from the symmetry of the deformation process. The present investigation of a commercial copper strip seems to yield an example in which annealing twins account unambiguously for the principal orientations present. It proves to be a case, also, for which the recrystallization texture cannot be viewed as derived from the deformation texture by a first or second-order twinning mechanism. Materials and Methods The samples investigated were of secondary copper (melted in belgium) to which 0.19 per cent iron had been added to raise the recrystallization temperature. How much the orientation characteristics of this metal can be ascribed to the iron content and how much to other impurities or to melting and pouring practice have not been investigated.* The rolling was done in one direction only, on a mill with rolls of about 20-cm diameter. A strip I. cm wide was reduced from 5 mm thickness to 0.05 mm by several cold passes at commercial speeds. The samples cut from this 99 per cent reduced strip were X-rayed throughout their entire thickness. A pole figure made soon after rolling and annealing was identical, within experimental error, with one that was made when a two-year interval occurred between rolling and annealing. X-ray patterns were made on a camera2 that traversed

Jan 1, 1947

By D. W. Horsfallt

The above paper gives a fair amount of information and is a useful addition to the literature on a subject of growing importance. I believe that more experimental results could have been given, together with more details of the modifications made to the plant that enabled it to operate with the success mentioned in the paper. One important omission is a definition of the word fines. As pointed out elsewhere!, this word is used very loosely.

Jan 1, 1980

By Alexander Blatt, Franz-Werner Gerressen

Power Point Presetation at DFI 2022

Sep 1, 2022

By Wern-ping Chen, Joseph Pratt, Thomas G. Brueckner, Tracy K. Lundin

To address and mitigate discharges from combined sewer overflows in the Providence, Rhode Island area, the Narragansett Bay Commission completed a comprehensive Combined Sewer Overflow (CSO) Facilities Plan in 1993 which included a series of deep rock tunnels. Since completion of preliminary design of the program in 1994, the program has been reconfigured in response to the Environmental Protection Agency’s (EPA’s) new CSO policy. The currently proposed system consists of a deep rock tunnel with two tunnel stubs which will provide230,000 cu m (62 million gallons) of storage at depths of up to 90 m (300 ft). This paper discusses the revised 5 km (3 mile) long deep tunnel system.

Jan 1, 1999

By Henry Wurtz

Observing in the Engineering and Mining Journal, of January 16th, 1875, page 35, a report of a brief discussion upon the nature and origin .of this unique and interesting coal, I take the liberty— on thus finding it a subject of interest to members of the Institute, and especially as my name came into this discussion—to cornmunicate some results which may serve at least to overthrow certain erroneous ideas that have prevailed. While I would not claim to -have made much approach to an understanding of this mineral—the whole of what I call Apozoic Mineralogy being as yet dark and almost unknown ground—yet I believe I have shown that few minerals of such importance and abundance, and so long before the world, have been so singularly misunderstood. On first examination of a sample of the substance to which the name of carbonite has been given, my surprise was not small, at failing to recognize in it one individual characteristic of true coke; neither the hardness, lustre, color, streak, porosity, sonorosity, structure, fracture, nor any of the so-called "pyrognostic" characters. Indeed, comparison with any coke, or variety or modification thereof, seemed altogether fantastic. Therefore the controversy regarding supposed trap dykes, whose existence at the locality is denied by some, seems useless, as we have no question of a natural coking, there having been no coking at all.

By Barnes E. L S

With the introduction of diesel powered loading and hauling equipment, a number of Australian mines producing less than one million tonnes per year from shallow orebodies have been dev- eloped by decline. This method of entry has the advantage of providing both flexible access and early prod uction. However, as the depth of mining increases so does the operating cost of haulage, due to the need for more trucks. This cost, together with increased capital requirements for both equipment and infrastructure, leads to the point where the alternat- ive of shaft hoisting must be con- sidered. With an established decline it is possible to provide an ore hoisting shaft using a drilled raise with subsequent stripping to a suitable size. Using DCF techniques and known equipment operating and capital costs, an economic comparison of the two systems is made to determine the limit- ing depth to which truck haulage can be used.

Jan 1, 1973