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By D. E. Traut

A fluidized countercurrent ion-exchange system was developed, operated, and evaluated by the U.S. Department of the Interior, Bureau of Mines. The system consisted of integrated multiple-compartment absorption and elution columns in which the solution flows were continuous except for short periods when resin increments were withdrawn. The exchange of uranyl carbonate between a simulated in situ uranium leach liquor and a strong-base ion-exchange resin together with the subsequent elution with an ammonium chloride solution was studied. The effects of the number of sections, section height, amount of resin withdrawal, solution flow rate, and column diameter were investigated. The kinetic and equilibrium relationships for the absorption and elution steps were also examined. The experimental data indicate a strong interdependence between variables. Solution retention time appears to be a major limiting variable in the absorption process, while resin residence time is the determining factor in the elution process. The column was efficient over a range of conditions, but close control was needed for optimum operation.

Jan 1, 1978

During the drilling campaign conducted between October, 1942; and May, 1943, to prove the extent of the scheelite deposit worked by King Island Scheelite N.L. at Grassy, King Island, Tasmania, 35 holes were drilled and 606 samples recovered and assayed for their content. Of these, 238 came from outside the limits of the orebody and were for the most part barren, although a few contained some scheelite. The present statistical analysis is made only of the 368 samples taken from diamond-drill cores of the orebody itself.Drilling Pattern and Sampling MethodsFrom the purely statistical viewpoint, it is realised that methods employed in selecting sites for diamong.-drilling, and of collecting samples from drill cores, do not give a completely unbiassed set of data for analysis. Fig. 1 is a sketch plan showing the relativepositions of the drillholes, which were inclined at an angle of depression of 50 deg. The pattern does not conform to a properly randomized and' regularly-spaced grid, the positions of the later holes being determined by the results obtained from previous holes.Statistically, the bias is, therefore, favourable. The unequal spacing of the drill holes and the lack of uniformity in direction of the lines along which the holes were drilled are unsatisfactory from the mathematical viewpoint; but it is realised that these irregularitiesare difficult to avoid in determining by the most economical methods the extent of such an orebody, and are dictated by geological rather than mathematical necessity.Sampling, also, is lacking in complete uniformity. Each sample is approximately 10ft. in length. However, owing to the fact that 100% recovery of core is rarely achieved, and actual lengths of samples taken are ,primarily governed by the length of the drill runs,and secondarily by lithological changes, there is a considerable amount of variation in the sample length.AssayingWith the exception of 28 samples from three drill holes all samples dealt with in this paper were assayed in the Melbourne University Ore-Dressing Laboratory of the Commonwealth Scientific and Industrial Research Organisation. These assays were given to the nearest 0.05% WOg as it was considered that more accurate determination was not possible. This fact has been taken into consideration in the frequency analysis below. The 28 assays determined by the Tasmanian Mines Department were given to the nearest 0.01%.

Jan 1, 1950

By F. C. Foshag, P. E. Wingrove

The Kayford, Boone and Nicholas Division of Bethlehem Mines Corp. operates a modern coal preparation plant in Van, WV. Since start-up of the Van plant in 1976 until the summer of 1980, the refuse handling system proved to be a costly maintenance problem and a material handling bottleneck. During the 1980 two-week miners' vacation, the original system - which included two screw conveyors and a drag conveyor - was replaced by an installation using two Flexowall steep angle belt conveyors. This paper describes the technical and economic analysis that led to the new installation and reviews its first year operating performance.

Jan 1, 1983

By J. R. Thoenen

This circular is the third of a series summarizing the technical problems involved in the production and preparation of sand and gravel. The first, Information Circular 6668, published in December 1932, discussed the problems involved in prospecting and exploration. The second, Information Circular 6689 (March 1933), dealt with the development of gravel deposits. This is part I of a paper designed to present a study of problems arising in the excavation of sand and revel and their delivery to the treatment plant. Other circulars are planned which will discuss preparation of the material for market, plant storage, and miscellaneous subject. Definitions For the purpose of this circular, excavation is defined as the recovery of sand and gravel from developed natural deposits and their delivery to a plant for market preparation.

Jan 1, 1934

By V. J. Sikora, W. J. McGuire

Several years ago, we used an electric analogue computer to study the effect of vertical fractures on the productivity of wells in expanding fluid-drive reservoirs. The results of this work were used both as a guide to research and as a basis for the design of actual fracturing operations. In 1958, Dyes, Kemp and Caudle' published portions of the data from this study. The results were released in 1959 to service companies for use in fracturing guides. The purpose of this note is to discuss the experimental conditions and assumptions which were made to derive the information which is already partially a matter of public record. ASSUMPTIONS This study applies to fractures which extend in a vertical plane symmetrically from the well. For simplicity, we chose to study the case of a well in a square drainage area with its fractures extending toward two of its nearest neighbors. We have assumed no migration of fluid across the boundary of this area. The quadrant shown in Fig. 1 models this system. We made the usual assumptions that the reservoir is homogeneous and isotropic, that the fluid is homogeneous and that production is effected by fluid-expansion drive. We also assumed that the fracture extends from top to bottom of the reservoir. Of more practical interest is our assumption that the fracture does not change the size of the drainage area. This premise is appropriate if all the wells in the reservoir are fractured in the same way. But where a single well is fractured, its drainage area may be enlarged at the expense of its neighbors. This could be of economic importance. The assumption that the fracture will not extend beyond the established drainage area of the well also limits the application of the results. Such long frac- tures will yield benefits in excess of those predicted here. When we assume homogeneity, we disregard the frequently observed zone of damage in the vicinity of the well. Where damage is severe, the benefits resulting from by-passing it will far exceed those predicted by this study. All comparisons were made of systems producing in the semi-steady state. By this we mean that equal volumes contributed equally to flow (pressure was dropping at a uniform rate throughout the system) when the rate of flow was observed. EXPERIMENTAL SET-UP We used the pool unit of an electric analyzer' in this study. The squase drainage system of a well was rep-

By Oliver Bowles

Marble is one of tile most beautiful and enduring materials employed in the construction industries. Because of its diverse colors, decorative patterns, and varying textures, it has furnished material for artistic architectural design for many centuries. The marble industry is described in some detail in Bureau of Mines Bulletin 106, The Technology of Marble Quarrying, which, unfortunately, is now out of print but may be consul ted at most large libraries. Onyx marble and travertine are discussed in Bureau of Mines Information Circular 6751. The purpose of this paper is to describe the main features of a distinctive group of ornamental marbles known as the serpentine marbles or verde antiques.

Jan 1, 1938

The Taupo Volcanic Zone inNew Zealand and the Philippine Mobile Belt in the Philippines are characterized by active subduction, active volcanism and high seismicity. The main factors affecting characteristics of geothermal systems in both countries are: tectonic setting, source magmas, maturity of the systems, and depth to the degassing magma body. Within New Zealand, geothermal systems are grouped into arc- and rift-type. Fluids in arc-type systems contain high amounts of volatiles (<20%), with high CO2/Cl, CO2/He, and N2/Ar ratios. Mantle-type volatiles predominate in rift-type systems. Philippine geothermal systems are largely arc-type, the topography is rugged, leading to the separation of water and vapour upflows, as opposed to the overlap found in New Zealand. The relatively shallow depths of degassing magma bodies in the Philippines results in steeper geochemical gradients, leading to higher proportions of arc-type magmatic water (>40%) and higher Cl contents (3000 - 10 000 mg/kg), Maximum temperatures are also higher, reaching up to >400¦C. Arc-type alteration assemblages in New Zealand and the Philippines are similar. Because Philippine geothermal systems are less mature, have higher temperatures and steeper geochemical gradients than New Zealand ones, advanced argillization is more widespread occurring down to depths of 2000 m. Mineral phases are more varied due to the active input of magmatic waters and the formation of vapor conditions at depth, forming P04-, B-, Li-, Ce-, F-, and Cl-bearing minerals at high temperatures. In the Philippines, high temperature magmatic-hydrothermal to contact metamorphic assemblages containing biotite, amphiboles and pyroxenes are relatively common, but rare in New Zealand.

Jan 1, 1995

By A. C. Fieldner

"Decline of the Beehive Coke OvenTwenty years ago a favorite theme of the crusader for fuel conservation was the enormous waste of valuable by-products incurred in the manufacture of blast-furnace coke in beehive ovens. Indeed, there was good reason for arousing the national conscience to this needless' loss of an irreplaceable mineral resource. In 1910, 83 per cent of the coke production was made in beehive ovens, from which surplus gas, tar, light oil, and ammonia, aggregating in value (at 1910 prices) 40 million dollars annually, were discharged into the atmosphere.In 1929, proportions were reversed and 90 per cent of the production was made in by-product ovens. The average value of by-products obtained in the production of 1 ton of coke in 1929 was $3.60, as compared with $1.16 in 1910, although the value of a ton of coke had increased only from $3.47 to $4.80. As shown in Figure 1,1 the production of by-product coke progressed rather slowly until 1915. War needs suddenly expanded the demand for coke and the by-products benzol and toluol for the manufacture of explosives. Except during the depression of 1921, this accelerating rate of production was maintained up to 1929, largely at the expense of beehive plants. The 1929 production of 60 million tons of coke will probably remain a record-breaking figure for several years. The developments which are now in progress in long-distance transmission of rural gas and in the utilization of volatile petroleum products and refinery gases for augmenting, city gas supplies may retard an other- wise accelerating demand for coke and coke-oven gas for domestic and industrial heating, Trends in Value of By-ProductsThe increasing value of by-products in comparison to the value of coke is shown in Figure 2. In 1913, the average value of by-product coke was $3.38, the value of the by-products per ton of coke was $1.41, and the cost of coal per ton of coke was $3,27, In 1929 not shown in figure) the value of the coke had risen to $4.80 per ton, the value of the by-products to $3.60, and the cost of coal per ton of coke to $5.07. The by-product values in were 155 per cent higher than in 1913, although the coke value had increased only 25 per And the cost of the coal 55 per cent. Actually the increase or the total value of coke plus by-products in this period was very little more than the increase in the coat of the coal, being 55per cent for coal and 60 per cent for coke plus by-products."

Mar 1, 1931

By Leo F. Reinartz

It was with humility that I accepted the invitation of the Board of Directors of our Institute to deliver the Twentieth Howe Memorial Lecture. Many previous lecturers could speak from personal experience of the great work done by Professor Howe. It was not my privilege to be one of his students but, indirectly, I came under the influence of his work many years ago. My mentor in Metallurgy at Carnegie Institute of Technology, Prof. Fred Crab tree, was an ardent admirer of Professor Howe and his work. Professor Crabtree taught me early to appreciate Professor Howe's love of truth and keen desire to find a scientific reason for every metallurgical phenomenon. In this early search, Professor Howe encountered many unexplainable facts. Nevertheless, in the classic text, "The Metallurgy of Steel," published in 1891, he indicated that he believed Research could light the way. Under the heading of "The Treachery of Steel" he said: "In the early use of Bessemer and Open Hearth Steel, many then unexplained and hence mysterious failures occurred. With our present knowledge, an easy explanation of most of them would probably have been seen. But even today certain unexplained and apparently inexpli- cable failures occur in steel; inexplicable in spite of full and intelligent investigation." Then Professor Howe continued to talk about "the trustworthiness of steel" in the following manner: First, the steel-maker has learned by experience. He knows today far better the effects of a high percentage of carbon or of phosphorus; of cracks, pipes and blow-holes; of segregation and imperfect mixing; of over-heating; of finishing too hot or too cold. Knowing, he guards against them more effectually, and keeps at home much steel that he would formerly have sent into the market. Those who would not, or could not learn and do, have been driven out of the business; the conditions necessary for producing good sound steel by the acid Bessemer and the acid Open Hearth processes have been mastered. By and by, the basic process came along with new conditions, new liabilities to unsoundness, a great hue and cry about mysterious fractures followed, and Lloyd's register provisionally forbade the use of basic steel. Much basic steel was irregular and brittle throughout; too much carbon, too much phosphorus, too cold teemings—imperfect mixing. Still there was little doubt that, with further experience, these difficulties of the basic process would be mastered as those of the acid process had been. This shows that Professor Howe could not take anything for granted. Believing that careful research would find the answer to all mysterious phenomena, he was several generations ahead of the practical acceptance and adoption of this principle.

Jan 1, 1943

By Leo F. Reinartz

It was with humility that I accepted the invitation of the Board of Directors of our Institute to deliver the Twentieth Howe Memorial Lecture. Many previous lecturers could speak from personal experience of the great work done by Professor Howe. It was not my privilege to be one of his students but, indirectly, I came under the influence of his work many years ago. My mentor in Metallurgy at Carnegie Institute of Technology, Prof. Fred Crab tree, was an ardent admirer of Professor Howe and his work. Professor Crabtree taught me early to appreciate Professor Howe's love of truth and keen desire to find a scientific reason for every metallurgical phenomenon. In this early search, Professor Howe encountered many unexplainable facts. Nevertheless, in the classic text, "The Metallurgy of Steel," published in 1891, he indicated that he believed Research could light the way. Under the heading of "The Treachery of Steel" he said: "In the early use of Bessemer and Open Hearth Steel, many then unexplained and hence mysterious failures occurred. With our present knowledge, an easy explanation of most of them would probably have been seen. But even today certain unexplained and apparently inexpli- cable failures occur in steel; inexplicable in spite of full and intelligent investigation." Then Professor Howe continued to talk about "the trustworthiness of steel" in the following manner: First, the steel-maker has learned by experience. He knows today far better the effects of a high percentage of carbon or of phosphorus; of cracks, pipes and blow-holes; of segregation and imperfect mixing; of over-heating; of finishing too hot or too cold. Knowing, he guards against them more effectually, and keeps at home much steel that he would formerly have sent into the market. Those who would not, or could not learn and do, have been driven out of the business; the conditions necessary for producing good sound steel by the acid Bessemer and the acid Open Hearth processes have been mastered. By and by, the basic process came along with new conditions, new liabilities to unsoundness, a great hue and cry about mysterious fractures followed, and Lloyd's register provisionally forbade the use of basic steel. Much basic steel was irregular and brittle throughout; too much carbon, too much phosphorus, too cold teemings—imperfect mixing. Still there was little doubt that, with further experience, these difficulties of the basic process would be mastered as those of the acid process had been. This shows that Professor Howe could not take anything for granted. Believing that careful research would find the answer to all mysterious phenomena, he was several generations ahead of the practical acceptance and adoption of this principle.

Jan 1, 1943

By G. Bierie

The conveying of bulk materials is prone to problems. These problems can reduce the capacity and efficiency of the plant, and even threaten the health and safety of the workforce. This presentation will look at new conveyor technologies systems, and how, used separately or in combination, they can improve material handling.

Jan 1, 2007

By William R. Yernberg

SME’s Arizona Conference was held at the Doubletree Hotel at Reid Park in Tucson on Dec. 5and 6, 2004. The annual conference is organized by the Arizona Conference Board of Directors, which represents SME sections in Arizona and adjacent areas. The conference provides an opportunity for individuals and corporations associated with mining in the region to get together each year to discuss the status of the industry. The meeting featured a keynote address and more than30 technical papers. Two years ago, the U.S. copper industry was facing on a run for two years now,” and “both precious metal and base metal prices are going up.” The increases in metal prices were attributed to development in China and other Asian countries. “With a population of 1.6 billion, China has recently created 80 million jobs,” said Silver.

Jan 1, 2005

By E. R. Bauer

Prolonged exposure to noise can cause permanent damage to the auditory nerve and/or its sensory components, known as noise induced hearing loss (NIHL). It is the most common occupational disease in the United States today. The Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) is addressing NIHL in the mining industry through several research efforts. This paper presents a general review of NIHL, the status of NIHL in mining, the results of the longwall noise surveys, and a review of the longwall engineering controls research efforts.

Jan 1, 2008

By T. Tholana

South Africa hosts some of the world?s largest known resources and reserves of minerals that are strategically important to the global economy. The country?s mining industry contributes significantly to the national economy in terms of gross domestic product, export earnings, corporate tax receipts, remuneration earnings, and employment. Platinum, gold, and coal are significant minerals because they make the largest individual contributions to these economic indicators. Several factors impact the cash cost performance of operations that mine these minerals, thus affecting the future sustainability of these operations, which are generally ?price-takers?. It is therefore important that the cash cost performance of operations for these key minerals is analysed. Commercially available industry cost curves can be used for such analysis. However, some companies may not be able to afford to purchase these curves. This paper presents a simple Microsoft Excel® algorithm for constructing the curves. It also demonstrates how the constructed industry curves were used to analyse the cash cost performance of South African mining operations for the three selected minerals for the period 2007 to 2011, which included the 2008 global financial crisis. The analysis revealed that the operations were affected by several global and local factors during the review period. The work reported in this paper is part of an MSc research study at the University of the Witwatersrand. Keywords cost curve algorithm, economies of scale, cash cost performance

Jun 1, 2013

By G. W. Jones

As part of its program for the promotion of safety, the Bureau of Mines has investigated various means of mitigating or eliminating the explosion hazards of combustible gases and vapors found in the mining and other industries. Knowledge as to the explosive characteristics of cyclopropane in air, oxygen, and other gaseous mixtures is of both theoretical and practical importance because cyclopropane is now used extensively in anesthesia. As such an agent it has many desirable characteristics, and increased consumption of this gas may be expected if the explosion hazards now attending its use can be minimized or eliminated. The present practice of using mixtures of approximately 20 percent cyclopropane and 80 percent oxygen should be discouraged because such mixtures are violently explosive and have led ,to fatal accidents.

Jan 1, 1940

By G. W. Jones

As part of its program for the promotion of safety, the Bureau of Mines has investigated various means of mitigating or eliminating the explosion hazards of combustible gases and vapors found in the mining and other industries. Knowledge as to the explosive characteristics of cyclopropane in air, oxygen, and other gaseous mixtures is of both theoretical and practical importance because cyclopropane is now used extensively in anesthesia. As such an agent it has many desirable characteristics, and increased consumption of this gas may be expected if the explosion hazards now attending its use can be minimized or eliminated. The present practice of using mixtures of approximately 20 percent cyclopropane and SO percent oxygen should be discouraged because such mixtures are violently explosive and have led to fatal accidents.

Jan 1, 1940

GENTLEMEN, lt is with much pleasure I meet you tonight at this the second meeting of the Australasian Institute of Mining Engineers, held in Western Australia, and I sincerely thank you for the honour you have conferred upon me in electing me as your President. I greatly appreciate the distinction, and will endeavour to fulfil the duties of the office to the best of my ability, and hope to prove a worthy successor to those gentlemen who have held the position before me. On behalf of the local members of the Institute, I extend a hearty welcome to the members from the other States of the Commonwealth, who have come so far to attend this meeting, and also to the non-members whom we have invited this evening. We are especially pleased to have Mr. Gregory, our Minister of Mines and Railways, and the Government and School of Mines officials with us; and I take this opportunity to thank the Premier, Mr. Gregory, and the Government officials for the assistance given us, and for doing so much to make the visit of our members from the other States so pleasant and instructive. I have also to thank the Mayor and Councillors of Kalgoorlie for the courtesy and hospitality given to our members, which is much appreciated.I assume you want me to follow the time-honoured custom of giving a Presidential address...

Jan 1, 1909

By F. Mendaña

The characteristics of the igneous and metamorphic bedrock, extra-hard and abrasive, of the Guadarrama Tunnels, a bi-tube project of length 28.4 km without any intermediate attack, are first commented upon. Next, a detailed discussion is given of the most relevant aspects of the performance of the four double shield type TBMs. The experience of this leads to various recommendations to be borne in mind in future designs of TBM having to work in rock of similar characteristics.

Jan 1, 2007

By Paul E. Melancon, Vincent C. Kelley, Dale F. Kittel

Uranium of the Grants region occurs predominantly in continental sandstones of the upper part of the Jurassic Morrison Formation, but significant lesser deposits are found in limestone of the Jurassic Todilto Formation and in black shale of the Cretaceous Dakota Formation. The deposits are disseminations that form runs ranging from a few hundred tons to several million tons. The ore consists mainly of uraninite, uraniferous carbonaceous material, coffinite, and such secondary oxidized minerals at tyuyamunite, carnotite, and uranophane. In sandstone, the ore runs were locallized by mudstone, interstitial carbonaceous material, and primary sand channel trends. In limestone, ore deposition was related to folds and fracture zones. The great bulk of production has come from the Ambrosia Lake mines in the Grants district and the Jackpile and Paguate mines in the Laguna district. The ores, which generally have been 0.20 to 0.30 per cent U3O8, are treated at mills operated by Kerr-McGee Corporation, Homestake-Sapin Partners, and The Anaconda Company, all in the Grants district. In 14·years after discovery in 1950, the deposits had yielded concentrates valued in excess of $800,000,000. Since deposition of the Jurassic host rocks, a geologic history involving tilting, faulting, erosion, changing ground-water environments, and oxidation has considerably influenced the existence and character of the deposits. It is evident that their ongm is not simple. However, a degree of agreement appears probable for a pre-Dakota age for the original ore runs, and, at Ambrosia Lake, two principal stages of ore formation, separated by Laramide faulting, are recognized. All earlier ores have been modified by Quaternary oxidation, solution, and enrichment during which time much secondary tyuyamunite, metatyuyamunite, carnotite were formed.

Jan 1, 1968

By Mukhopadhaya K. K, Cory A. H

The concept of using travelling magnetic fields created by linear motors was stimulated by Laithwaite who advanced ideas on motors with shaded poles (Laithwaite, 1968), rack and pinion motors (Laithwaite, 1970) as well as low speed, brushless motors and three dimensional motors (Laithwaite, 1973a and 1973b).Sudan (1963) and Sundberg (1969) had applied the concept to metallurgical processes. However, the use of travelling magnetic fields has not been used widely to produce conditions for the separation of magnetic from non-magnetic minera1s or even magnetic materials from non-magnetic materials, although some attempts were made by McCarthy (1922), Davis (1934), Dean, Gottschalk and Davis (1934) and Gottschalk (1934).Laithwaite (1973, a) while working with linear motors made suggestions for designing separators and in the work described here, the observations of Laithwaite and others are extended to determine the characteristics of the motor with a view to using it as a magnetic separator.

Jan 1, 1980