Search Documents

By André. C. Louw

Diamond production from the reworked beach and river channel gravels along the west coasts of South Africa and Namibia is well known throughout the world, not only for the exceptional quality of the diamonds, but also for the sheer scope of the operations. To date an estimated 140 million carats have been produced from the resource worth some US$40 billion in today's money terms. It is therefore not surprising that it didn't take long before the attention turned towards the possible extension of this valuable diamond resource on similar submerged beaches in the adjacent territorial waters of South Africa and Namibia. This has proved to be a very successful move as the marine production in Namibia today constitutes 48% of that country's total diamond production. Although small scale recovery of diamonds from the sea commenced in the 1950's, the first large scale production came from the operations of the Texan entrepreneur, Sam Collins, in the 1960's. The De Beers Group, which took over Sam Collin's operations in 1969 had all the concession areas, as well as the financial and human resources to tackle the new mining frontier in the correct way by years of data gathering (ie diamond reserves and seafloor terrain studies) before commencing with large scale mining operations in the 1980's. Those who are familiar with the beach mining operations along the South African and Namibian west coasts will have appreciation for the daunting task of surgically removing the payable portion of diamond deposits from the non-payable material on the one hand, and the complex uneven fractured and gullied bed-rock floor of the deposits on the other hand. Not to mention the additional complexities of large boulders and hard calcretised diamond gravel layers (conglomerate) which are sometimes associated with the deposits. It was a natural development that the sea diamond mining operations were approached with the known information of the land operations, attempting to duplicate land mining operations in the sea, but taking cognisance of the variations of the terrain in the different areas. For instance, we encounter the following variations, and combinations, off the Namibian Coast. ? Close inshore - holocene sand cover often masks large areas of potentially diamondiferous gravels. ? In midwater areas (40m - 100m)

Jan 1, 1998

By AIME AIME

The following abstract of the minutes of the final Adjourned Annual Business Meeting, held Nov. 12, 1912, in the office of the Institute, 29 West 39th Street, New York City, is here presented for the information of the membership at large. On the announcement by the Secretary that there was a quorum present, President James F. Kemp called the meeting to order. The minutes of the Adjourned Annual Business Meeting of Oct. 7, 1912, were read and approved. (Sec p. xi,Bulletin No. 71, November). Prof. Jos. W. Richards, in behalf of the Special Committee of the Board of Directors and the Council (Messrs. Richards, Kirchhoff, and Rand), withdrew the two proposed amendments to the Constitution offered by the said Committee at the Adjourned Annual Business Meeting of Oct. 7, 1912. (See Bulletin. No. 70, October, 1912, p. vi., and Circular Announcement No. 8, Oct. 15, 1912, p. 15.) Professor Richards presented a syllabus of the proposed amendments to the Constitution and By-Laws prepared by the Special Committee. Several members present discussed various sections of the proposed Constitution, and the Committee advised that the suggestions would he duly considered before submitting the final document, which would be duly presented and sent to the membership at large at least 30 days before the next Annual Business Meeting, Feb. 18, 1913. Professor Richards presented a resolution, seconded by Mr. Kirchhoff, making a change in the present Certificate of Incorporation, so that it would conform to the proposed changes in the Constitution and By-Laws; said resolution was unanimously adopted. Professor Richards presented another amendment to the Constitution, which had been purposely omitted from the printed list, but had been requested by many members, namely, the creation of a " Class of Fellows." This question was freely discussed at the Cleveland meeting (see Bulletin No. 71, November, 1912, p. 1348), and in view of the diversity of opinion it was-decided to present it in separate form for separate action of the membership at large at the Annual Business Meeting, Feb. 18, 1913. In answer to question, the President announced that the proposed amendments to the Constitution and By-Laws presented by Messrs. Corning and Stone at the Adjourned Annual Business Meeting, Oct. 7, 1912, and published in Circular Announcement No. 8, Oct. 15, 1912, were still on record. Professor Richards presented a syllabus of the proposed amendments to the By-Laws, and several sections were discused by members present, but no action of record was taken. Mr. Charles F. Rand read a letter from Mr. L. K. Armstrong, Sec-retary of the Spokane Local Section of the Institute, referring to the proposed amendments to the Constitution, and he announced that many of Mr. Armstrong's suggestions were, in one form or another, already incorporated in the proposed amendments submitted by the Special Committee. A special vote of thanks was passed to Dr. Albert R. Ledoux for the valuable assistance rendered by him to the Special Committee in the preparation of the proposed amendments to the Constitution and By-Laws.

Dec 1, 1912

By G. M. Potter

During investigation of the occurrence of manganese deposits in the western United States, the Bureau of Mines collected 2-ton samples of 4 ores from 3 properties in northeastern Nevada. Laboratory tests were made to determine the amenability of these ores to ore-dressing methods of concentration. The Caviglia-Vietti property is situated 11 miles southeast of Ely, White Pine County, Nev. The ore deposits are lenticular veins and irregular masses found in limestone fracture zones and along the contact of limestone and underlying shale. Two samples, of the ore were tested: Lot A, from the Vietti shaft, and lot B, from the. Caviglia shaft.

Jan 1, 1954

By Campbell Brown G A

IN 1904-5 diamond drilling operations in the Mount Morgan mine proved the presence of some millions of tons of rich copper-gold ore, averaging about 45%to 50%silica and 22%Fe as sulphide. To smelt this ore in blast furnaces, without previous concentration, large quantities of basic flux were required. Unlimited quantities of cheap limestone were available at Marmor, on the GladstoneRockhampton railway, 50 miles from Mount Morgan, but the supply of iron flux was a more difficult problem. Smelting Operations started with one furnace in January, 1906, using as flux low-grade sulphide ore from the mine, containing very little silica. When the second furnace was blown in this was supplemented by ironstone from small deposits in the immediate district. It was recognized that these sources of supply would be insufficient to keep the full plant going after the third furnace had been blown in. Accordingly, the deposits at Kabra and Mount Etna were opened, neither of which proved capable of supplying the quantity required-viz., 1000 tons per week. Negotiations were meanwhile being conducted with the Marble Island Iron and Limestone Co. to obtain the right to mine at Iron Island, where a sufficiently large deposit was known to exist. Shipments from this source commenced in January, 1907, and ceased at the end of July of this year, when the metallic flux from...

Jan 1, 1911

By K. Webb, M. Hohn

"This paper reviews the evolving Ontario mining regime for mining industry-Aboriginal engagement and its apparent alignment with court decisions, domestic law, emerging international norms, mining industry rules, and mining firm-Aboriginal agreements, drawing on publicly available commentary from government officials, the private sector, and Indigenous communities. This paper provides a preliminary analysis of the potential implications of the new regime, especially for the mining industry and Aboriginal communities and, on that basis, discusses possible future developments.RÉSUMÉ Le présent article analyse le régime minier de l’Ontario pour l’engagement entre l’industrie minière et les Autochtones et son harmonisation avec les décisions des tribunaux, le droit interne, les nouvelles normes internationales, les règles de l’industrie minière et les ententes compagnies minières- Autochtones en se basant sur des commentaires, disponibles publiquement, d’officiels gouvernementaux, du secteur privé et des communautés autochtones. Cet article fournit une analyse préliminaire des implications potentielles du nouveau régime, surtout pour l’industrie minière et les communautés autochtones et, en s’appuyant sur ces données, il traite des futurs développements possibles."

Jan 1, 2016

By John K. Alley

Fibrous silicon carbide was produced by thermal decomposition of certain silicates contained in graphite crucibles. Induction heating was used to produce the necessary temperature and thermal gradients. Both green and white fibers were mainly the beta modification even though each color grew within a different temperature zone. Alpha silicon carbide, present in insufficient amounts for X-ray detection, was identified by electron diffraction. The white fibers formed in a zone between 1,365° and 1,634° C (±50° C). The green fibers (less contaminated) formed in a much more narrow zone between 1,650° and 1,672° C (±50° C). The average lengths and widths of microscopic fibers grown by this method were 1.5 mm/0.002 mm (white) and 1.2 mm/0.0035 mm (green); however, same fibers observed by electron microscope had cross-sectional measurements of 150 to 300 A. Both differential thermal analysis and thermogravimetric analysis showed that silicon carbide fibers oxidized in air at temperatures above 500° C. Fibrous silicon carbide was indexed as a cubic cell with the dimensions a = 4.358 A. The density calculated from X-ray data was 3.217 g/cm3.

Jan 1, 1963

A knowledge of airway friction factor (K-factor) is necessary to designing mine ventilation systems for least cost and optimum effectiveness. The friction factor used must be accurate and reliable to estimate correctly roadway resistances and pressure sources for required flows. Though the resistance to flow offered by mine airways has been an object of study over the last half century, no accurate relation has yet been established from which the prediction of the resistance of a projected airway can be made. In Kentucky, only limited and incomplete data on local K-factors are available. Therefore, there is a need for field investigations to determine these values in-situ for existing mining conditions. The author describes a study concerning K-factor that was carried out in ten coal mines, located in eastern and western Kentucky. The results of these investigations are presented in both tabular and graphical form.

Jan 1, 1991

Reduce well construction and operation costs associated with in situ leach mining while increasing mineral recovery. Approach To accommodate the size of centrifugal pumps presently in use, in situ leaching production wells are typically drilled to 6 inches in diameter, while monitor wells are drilled to measure 4 inches in diameter. However, in order to reduce the cost of drilling these larger diameter wells and to increase recovery, the Bureau has developed jet pumps which have smaller diameters than centrifugal pumps of the same capacity. This allows both production and monitor wells to be drilled smaller. Bureau estimates indicate that the cost of drilling a 3-inch-diameter production well at in situ leaching operations would be about 35 percent less than the cost of a 6-inch well. Similarly, the cost of drilling a 2-inch-diameter monitor well would be about 26 percent less than the cost of a 4-inch well. Such significant savings in the cost of drilling these wells would effect a substantial reduction in total capital cost. Use of the new jet pumps can also increase the percentage of recovery because less costly wells allow closer well spacings, improving the distribution of the leach solution. How the System Works After the borehole is cased, the new small-diameter jet pump, along with piping and accessories, is installed and connected to a centrifugal pumping unit on the surface. High-pressure water from the surface pump is forced through a nozzle into the venturi of the jet type pump injector. This jet action lifts the leach and mineral-bearing solution to the surface.

Jan 1, 1984

By Paul Fouche

The past decade has seen a tremendous revival of the base metal industry in Africa, coupled with an unprecedented increase in the prices of base metal commodities in the last couple of years. The theme of the 4th Southern African Base Metal Conference, is therefore, ?Africa?s base metals resurgence?. This conference will explore the contributions made by the mining and metallurgical disciplines to the base metals industry in Africa. It will also investigate how the base metals industry in Africa can capture the maximum potential from the increase in base metal prices through research, innovative thinking, new ways of operating and project implementation. The conference will also consider the influence of Europe?s REACH programme on the base metal industry in Southern Africa. The conference will include a technical visit to Rössing Mine (Uranium) and will be followed by technical visits to Ongopolo (copper), Skorpion Mine (zinc) and Rosh Pinah Zinc Corporation(zinc and lead). The conference, to be held in Swakopmund, Namibia, also confirms the commitment of the Southern African Institute of Mining and Metallurgy (SAIMM), to hosting a regular forum on base metals in the Southern African region. Swakopmund is an ideal conference venue for local and international mining and metallurgical professionals to be exposed to the latest advances in exploration, resource evaluation, projects and technological advances in Southern Africa?s base metal industry. The organising committee is looking forward to your participation at the conference in July 2007.

Jan 1, 2007

"Mechanical alloying (MA) synthesizing technology and thennohydrogen processing (THP) were utilized to produce nanocrystalline Ti-MMC's reinforced by TiB intermetallic compound by using TiH2-B powder mixtures. Powders MA'ed up to 8 hours were examined by X-ray diffraction and SEM study. All MA'ed powders afterwards were HIP'ed at 700, 800 and 950EC for 1 hour. Detailed XRD, SEM and TEM study of the samples were carried out to determine the structure and micrography of the Ti-TiB MMC material processed by MA+THP approach followed by HIP'ing at high temperatures.IntroductionThe fiber reinforced titanium base composites [1,2] which possess a great resistance to high temperature have been investigated. In these studies fibers of C and SiC were used as reinforcing materials. However, these fibers react with Ti-matrix at elevated temperature resulting in product formation at the interface between the matrix and the fiber. Because of the chemical reactions, strength of the product MMC material diminishes.In conventional techniques of whisker reinforced composite material production, the mixtures of matrix metal powders and dispersed fibers are consolidated by hot pressing, HIP and/or hot extrusion. These techniques, however, have some shortcomings. Hard and brittle fibers could be broken during mixing cycle of the processing. Consolidation techniques could also be the cause for fiber breakdown. Attaining of the uniform dispersion of fibers into the metal matrix is not an easy process. The chemical reactions at elevated temperature exposures in the interface between the matrix material and fiber reinforcement cause product formations leading to poor mechanical properties."

Jan 1, 1998

By Thiemo Hagedorn, Gerhard Weissbach, Ralph Bergmann, Wilhelm J. Kogelmann

The objective of this unique method is to multiply the advance rate of conventional tunneling while improving both ground control and the safety of the crew. The high advance rate is achieved by concurrent rock excavation and installation of concrete lining at fully synchronized work phases. The novel TACHUSMATIC system consists of a high-production, robotic cutter boom, an automated slip form and continuous mucking and conveying. This novel system utilizes the inherent bearing capacity of the rock that is activated by a small, initial deformation. The supporting resistance is then provided both by the rock mass itself and the pumped in concrete lining. During the hardening of the concrete, the hydraulic cylinders of the TACHUSMATIC automatically apply the appropriate support resistance, thus providing safe ground control. This novel tunneling system is practically a fully automated, fail-safe NATM that does not require highly skilled engineers and crew. The TACHUSMATIC can be used for construction of circular, rectangular and horseshoe-shaped tunnels. When equipped with the Alpine Multi-Tool Miner (MTM) systems, the machine can work in a wide range of ground and rock conditions. The use of novel, diamond-tipped cutter bits (picks) will increase hard rock cutting capabilities and will significantly reduce pick consumption. Because of its moderate cost, the novel system is an economic alternative to conventional tunneling even at short drivages. A new installation is cost-effective for tunnels longer than 750 meters (2,500 ft.) At a typical tunneling project, the cost permeter is about 25% lower than with conventional methods.

Jan 1, 2003

By AIME AIME

THE week, of April 5 will long be remembered by those that attended the Birmingham meetings of the Open-Hearth and Blast Furnace committees of the A.I.M.E. Iron and Steel Division. Birmingham iron and steel own received the 450 delegates with open arms; described and discussed their southern metallurgical practices and problems and compared experiences with their northern brother metallurgists in two days of technical sessions on Wednes-

Jan 1, 1937

By Brian Fulcher, Matthew Bartlett, Jarrett E. Carlson

This paper discusses the challenges to complete the construction of two large underground Metro stations and connecting tunnels in the Tren Urbano system. The completion work includes the installation of specialized mechanical and electrical systems, extensive architectural finishing as well as coordination with systemwide power and controls installed by others. A unique feature of this project was the simultaneous design and construction of the structural/civil/architectural/mechanical/electrical works by KKZ separately from the power and control systems under the management of the Owner, its consultants and other contractors. Completion of this project comes after almost six years of continuous design and construction in a dense urban environment. The project was confronted by many challenges that could only be met with the combined efforts of the Joint Venture team in close cooperation with the Owner and its System wide Contractor. This paper will also address many of the major design and construction changes implemented to suit the Owner’s requirements.

Jan 1, 2003

By Peter Ehren

Global Geoscience is developing a Rhyolite Ridge project, a shallow boron-lithium resource deposit, located in Nevada about 25 km from Albermarle’s Silver Peak operation. The main minerals of interest are the boron mineral searlesite (40%wt) and lithium containing clay minerals. These minerals are found among principally calcite, feldspar, muscovite, dolomite, and quartz. The equivalent commercial value is about 7–9% boric acid (H3BO3) and 0.8–1.0% lithium carbonate (Li2CO3) equivalents. Selective agitated leach tests at SGS Lakefield laboratory showed that searlesite can be acid leached between 20 and 75 °C and at a pH lower than 4. On the other hand, lithium can be leached between 20 and 75 °C and at a pH lower than 1. In other words, lithium can be recovered at low temperatures if sufficient free acid is available, which gave the motivation to investigate heap leaching of the mineral. The PLS contains boric acid, magnesium, sodium, lithium, potassium aluminium, and iron sulfates.

By James W. Myers

The Bureau of Mines studied factors affecting ignition of coal mine refuse and on methods for control of burning. Laboratory experiments showed that air permeates more readily through segregated than through nonsegregated refuse and that air permeability is greater through coarse than through fine particle refuse. Minus 3-1/4-inch refuse ignites spontaneously more readily than minus 1/4-inch refuse. The burning of a 1,000-pound conical coal pile was con-trolled by capping with an 18-inch-thick layer of minus 1/4-inch refuse containing 37 percent combustible. In field trials, the burning of refuse at operating mines was controlled by capping with a layer of fine refuse. Water, applied as a spray or by injection, quenched surface flames and cooled the burning waste. Inspection of refuse piles at operating mines showed that the spontaneous ignition tendency is affected by the exposed surface relative to the total volume and the segregation of particles during dumping.

Jan 1, 1966

By W. M. Peirce

Commencing in 1922, each year a lecture has been presented to the Institute of Metals Division at this February meeting. The range of subjects has been very- broad. Some speakers have dealt with the most advanced work in the very heart of the science of physical metallurgy. Others have stimulated our imaginations by discussing the most recent progress in related fields of science. Others have told us of the latest art, which is at any moment of greater practical importance than the latest science, of metals. I feel that this broad precedent in the choice of subjects will justify my choosing to talk about some of the prosaic details of how, during the last generation, industry has effectively organized research to accelerate progress in our own and all other fields of science and related art. A number of years ago I visited one of this country's well-known research laboratories and had the pleasure of chatting for a few minutes with its equally well-known director. Being particularly interested at the time in the organization problems connected with industrial research, I broached that subject. My host stated in effect that he didn't believe in organized research. He was, of course, resorting to a rhetorical hyperbole. to pain: out the danger of overorganization which can so easily drift into regimentation and destroy individual initiative. Actually nearly all of us, much as we cherish our personal freedom of action, believe in organization because the history of progress in every field of human activity has been a history of men learning to work together, to cooperate, to create an efficient division of labor. We use organization to achieve this coordination. At the same time our form of organization must not stifle individual initiative or it will prove a deterrent rather than an aid to accomplishment. Research, too, must be organized for greatest achievement but especial skill and care are perhaps needed to avoid stifling the initiative of the individual workers. I have, of course, followed with keen interest and much benefit the vast amount . that has been said and written on this subject in the past twenty years but I still find new stimulation in discussions with my good friends working in this field. It is my hope that this discussion may serve a like purpose. It would be ungracious not to make due acknowledgment to the many able contributors to this particular phase of human progress, but their very number and the great volume of their writing makes it impossible to trace to any one individual a particular significant and valuable idea. I shall content myself therefore with this general acknowledgment and with acknowledgment of the specific debt that every research man owes to those who have so ably kept before the public, and in particular before industrial executives, the place of research in the modern scheme of things' Because of the legitimate publicity thus given to research, the day is past when any

Jan 1, 1944

By W. M. Peirce

COMMENCING in 1922, each year a lecture has been presented to the Institute of Metals Division at this February meeting. The range of subjects has been very broad. Some speakers have dealt with the most advanced work in the very heart of the science of physical metallurgy. Others have stimulated our imaginations by discussing the most recent progress in related fields of science. Others have told us of the latest art, which is at any moment of greater practical importance than the latest science, of metals. I feel that this broad precedent in the choice of subjects will justify my choosing to talk about some of the prosaic details of how, during the last generation, industry has effectively organized research to accelerate progress in our own and all other fields of science and related art. A number of years ago I visited one of this country's well-known research laboratories and had the pleasure of chatting for a few minutes with its equally well-known director. Being particularly interested at the time in the organization problems connected with industrial research, I broached that subject. My host stated in effect that he didn't believe in organized research. He was, of course, resorting to a rhetorical hyperbole to point out the danger of overorganization which can so easily drift into regimentation and destroy individual initiative. Actually nearly all of us, much as we cherish our personal freedom of action, believe in organization because the history of progress in every field of human activity has been a history of men learning to work together, to cooperate, to create an efficient division of labor. We use organization to achieve this coordination. At the same time our form of organization must not stifle individual initiative or it will prove a deterrent rather than an aid to accomplishment. Research, too, must be organized for greatest achievement but especial skill and care are perhaps needed to avoid stifling the initiative of the individual workers. I have, of course, followed with keen interest and much benefit the vast amount that has been said and written on this subject in the past twenty years but I still find new stimulation in discussions with my good friends working in this field. It is my hope that this discussion may serve a like purpose. It would be ungracious not to make due acknowledgment to the many able contributors to this particular phase of human progress, but their very number and the great volume of their writing makes it impossible to trace to any one individual a particular significant and valuable idea. I shall content myself therefore with this general acknowledgment and with acknowledgment of the specific debt that every research man owes to those who have so ably kept before the public, and in particular before industrial executives, the place of research in the modern scheme of things. Because of the legitimate publicity thus given to research, the day is past when any

Jan 1, 1944

By W. M. Peirce

Commencing in 1922, each year a lecture has been presented to the Institute of Metals Division at this February meeting. The range of subjects has been very- broad. Some speakers have dealt with the most advanced work in the very heart of the science of physical metallurgy. Others have stimulated our imaginations by discussing the most recent progress in related fields of science. Others have told us of the latest art, which is at any moment of greater practical importance than the latest science, of metals. I feel that this broad precedent in the choice of subjects will justify my choosing to talk about some of the prosaic details of how, during the last generation, industry has effectively organized research to accelerate progress in our own and all other fields of science and related art. A number of years ago I visited one of this country's well-known research laboratories and had the pleasure of chatting for a few minutes with its equally well-known director. Being particularly interested at the time in the organization problems connected with industrial research, I broached that subject. My host stated in effect that he didn't believe in organized research. He was, of course, resorting to a rhetorical hyperbole. to pain: out the danger of overorganization which can so easily drift into regimentation and destroy individual initiative. Actually nearly all of us, much as we cherish our personal freedom of action, believe in organization because the history of progress in every field of human activity has been a history of men learning to work together, to cooperate, to create an efficient division of labor. We use organization to achieve this coordination. At the same time our form of organization must not stifle individual initiative or it will prove a deterrent rather than an aid to accomplishment. Research, too, must be organized for greatest achievement but especial skill and care are perhaps needed to avoid stifling the initiative of the individual workers. I have, of course, followed with keen interest and much benefit the vast amount . that has been said and written on this subject in the past twenty years but I still find new stimulation in discussions with my good friends working in this field. It is my hope that this discussion may serve a like purpose. It would be ungracious not to make due acknowledgment to the many able contributors to this particular phase of human progress, but their very number and the great volume of their writing makes it impossible to trace to any one individual a particular significant and valuable idea. I shall content myself therefore with this general acknowledgment and with acknowledgment of the specific debt that every research man owes to those who have so ably kept before the public, and in particular before industrial executives, the place of research in the modern scheme of things' Because of the legitimate publicity thus given to research, the day is past when any

Jan 1, 1944

By K McLeod

{Figure 1} The Placer Dome-Western Areas Joint Venture?s South Deep Twin Shaft Complex, has been planned and dreamt of for nearly 20 years. [ ] The gold reserve at the bottom of these shafts is one of the largest single intact gold deposits remaining in the world today, containing an estimated 57 million ounces. This is about the size of the fictitious reserve created by inventive prospectors for the infamous BREEX scam in Kalimantan about ten years ago and about the size of the reserve Harmony claims as its own in it?s current hostile takeover bid for Gold Fields. So it is certainly of the magnitude that dreams are made of. [ ] {Figure 2} The unique orebody lies in a continuous, highly concentrated, thick deposit, an estimated twelve kilometres along dip and a two kilometre wide strike. Due to the thickness of some sections of the reef, up to 60 metres in places, bulk mining methods will be required for it?s extraction. [ ] {Figure 3} The twin shaft system comprises a main shaft which had an initial design depth of 2765m and a ventilation shaft of 2760m, making them the world?s deepest to be sunk in a single lift. The shafts were

Jan 1, 2005

CONTENTS [The Nature of Strain Markings in Alpha Brass (paper by J. E. BURKE and C. S. BARRETT, Met. Tech. Feb. 1948. TP 2327). ......................... 2 X Ray Studies of Twinning and Untwinning in Magnesium Alloys (paper by J. B. HESS and R. L. DIETRICH, Met. Tech. Feb. 1948. TP 2328) ................ 11 ]

Jan 1, 1948