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By F. Windolph

There are no hard and fast rules for building tailing dams, and each case has to be analyzed individually because of special conditions encountered at each location. Certain criteria are used for building dams at Climax, Colo., where they must be placed in rather steep mountain valleys on foundations that are practically impermeable. The tailing is relatively coarse, and a coarse fraction stays near the berm where it is deposited, while most of the fines flow with the water to the pool. Thirty years experience has led to certain design for toe dams, decanter lines and towers and tailing dams. A new tailing disposal area, started at Climax in 1958, will ultimately have a height of 495 ft and impound about 300 million tons. The following applies to the construction of this new tailing area.

Jan 11, 1961

By P. W. Neurath

IN recent years the domain theory of ferromag-netism has been put on a sound experimental and theoretical basis. But its application to one of the most widely used high quality magnetic materials, the cold-rolled grain-oriented 3 pct Si-Fe used in transformer cores, has been rather difficult because of the complexity of the domain structure of the poly crystalline sheet material. This paper presents some experimental data for this material, showing the relation between plastic and elastic stresses, 60-cycle watt losses, and the domain structure as observed visually. Only a very tentative qualitative explanation of the effects will be attempted. Some initial results were reported earlier.'

Jan 1, 1957

By Axel Sahlin

The day is long past when linen and cotton rags were the exclusive raw material of the paper-trade. Wood-fiber, chemically or mechanically prepared, straw, hemp and Esparto grass have largely supplied the demand, which the old materials did not suffice to fill. But even these newer fibers have been of late supplanted, to some extent, by mineral pulp. Weighting and filling materials have also been resorted to, partly to give body to the fabric, partly to increase its weight and reduce the cost per pound. China clay, sulphate of lime and soapstone have generally been employed as loading materials. Even though these materials lack fiber, their addition must by no means be viewed, as it too generally is, entirely as an adulteration. No doubt, to a certain extent, they weaken the paper ; but for ordinary grades the addition of these non-fibrous substances is a positive advantage, as they close the pores between the fibers and lend to the paper a great degree of opaqueness and a superior finish. Fibrous talc, as a form of pulp, has the same effect, without appreciably weakening the paper. When, therefore, some fifteen years ago, fibrous talc in large quantities, and of marvellous purity and whiteness, was discovered in the neighborhood of the town of Gouverneur, it was not long before the

Jan 1, 1893

By B. E. Mix

THE present methods of unloading ore and coarse-crushing at the Magna plant of the Utah Copper Co. are the developments of the past five years. Hand dumping and breaking have given way to the rotary car dump and large gyratory; and the bucket elevators and stationary screens have been replaced by conveyors and shaking screens. The coarse-crushing plant may be broadly divided into two units: the primary crushing and the secondary crushing, or primary roll, unit. The former was erected in 1923; with the exception of the excavation, the construction was carried on by forces of the company. Excavation was started in the middle of March, the first concrete was poured July 16, erection of the steel building started Oct. 30, and the unit was com-pleted and operating Dec. 30. The unit has a capacity of over 24,000 tons of ore per day, and cost more than a million dollars. Remodeling of the primary-roll unit extended over a period of years preceding this, some of the work having been done as early as 1918.

Jan 8, 1925

SEC. 1. The membership of the Institute shall comprise seven classes, namely: 1. Members; 2. Honorary Members; 3. Senior Members; 4. Associates; 5. Junior Members; 6. Rocky Mountain Members; 7. Junior Foreign Affiliates. All shall be equally entitled to the privileges of membership, excepting that no member of any class whose residence shall be outside of the United States of America, except those residing in Mexico and Canada, shall be entitled to vote. SEC. 2. Members: A person to be eligible for election or transfer into the class of Member must be at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy, or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. This shall not apply to Rocky Mountain Members.

Jan 1, 1946

By E. P. Pfleider

THE history of fundamental research in mining is not one of which the profession can be particularly proud. It has been one of the slowest industries in applying the fundamental sciences to the solution of many of its more difficult problems. True, many of the processes are not adaptable to laboratory techniques, and much of the work must, of necessity, be done in the field. It is for this reason that the mining executive seldom has been conscious of the value of research on a laboratory scale on problems pertaining strictly to mining. Most of them, however, fostered much testing in the allied fields of ore dressing and metallurgy.

Jan 7, 1951

By Ying-Chu Hoh, Renato G. Bautista

The chemically based models previously developed to describe and predict the distribution coefficients and separation factors for several different single and multicomponent metal extraction systems are presented in a more general form in this paper. The degree of formation of the aqueous phase inorganic metal complexes, the extraction mechanism of the complexes, and the equilibrium constant for the extraction reaction are used in the development of the models. The concept has been successfully applied to extraction systems where the organic solvent extracts an ionic species and where the organic solvent extracts only the neutral species. In addition, a model to describe a system where the organic solvent is extracting several extractable species has been derived on the same basis

Jan 1, 1981

By W. R. Ingalls

THE MAJOR use of spelter has always been for the coating of iron and steel products, the process of coating being known as "galvanizing" and the products themselves as "galvanized," except for a couple of years during the war, when the consumption for brass making became superior, in the United States at least, owing to military demands. Since 1919, however, the consumption of spelter for galvanizing has regained the premier position, but not with such a long lead over brass making as previous to the war. The last development is ascribable to two main reasons, viz., an increased demand for brass in new industries, especially automobile manufacturing; and a diminished use of spelter per unit of iron and steel galvanized. MAJOR IMPORTANCE OF SUBJECT The last mentioned matter has already been the subject of some discussion and of some literature. The galvanizers have been charged with deliberately thinning their zinc coatings, with the consequence of producing inferior goods and thereby jeopardizing the whole galvanizing business. Zinc producers have been concerned about this, out of consideration of both the less use of zinc per unit of iron and steel and the fear that, the number of units produced may be curtailed. It has been argued, among other things, that the present policy of American galvanizers would impair their ability to compete in foreign markets with British galvanizers, who have been represented as making a superior product.

Jan 7, 1923

By A. G. H. Andersen

A FEW years ago, while the writers worked on the constitution of ternary and quaternary alloys consisting mainly of iron, chromium and silicon1,2 some information on microstructures and hardness, not incor-porated in the published work, was obtained. It has not been possible to do any further work on the properties of the alloys. The information possessed is hereby presented for the interest it. may have in connection with the constitution of the alloys.

Jan 1, 1937

By William I. Watson

Problems encountered in beneficiating mineral raw materials become increasingly difficult as there is a shift to lower grade and more complex raw materials, and because of the economic need to strive for ever higher recoveries, higher grade products, and lower processing costs. Methods of attacking the many problems should include not only the familiar chemical and physical tests and equipment, but such techniques as X-ray analysis, infra-red analysis, differential thermal analysis, and the use of electron and X-ray microscopes. Many people in the mineral-treating field are unfamiliar with these newer methods and techniques. The differential thermal analysis method, in particular, does not seem to be very well known, even though it offers interesting possibilities in the study of many ore treatment problems.

Jan 7, 1959

By E. J. Quinn, M. F. Fogler

In a recent paper, Rawdon and Mutchlerl gave some exceptionally interesting results on the Brinell and scratch hardness of severely cold-worked metals. In their work, they found that, on continued cold rolling, the metal hardened up to a particular point and then reversed and became softer; this was true for both Brinell and scratch hardness values. The generally reported behavior2 of metals, with respect to Brinell tests on cold-worked material, is that the metals harden up to a certain point and then, on further cold rolling, no change in Brinell hardness occurs. Jeffries and Archer3 state that there is little difference between the scratch hardness of annealed and cold-worked metals; the work of Faust and Tammann4 also indicated no difference between the hardness of annealed and cold-worked copper. Rawdon and Mutchler found, when they plotted the reduction ratio (initial thickness divided by thickness after rolling) against the hardness value for the cold-rolled material, that the hardness number increased up to a reduction ratio of about 3 and then decreased and became even smaller than that for the annealed metal. This behavior was reported for both scratch and Brinell hardness; Figs. 1 and 2 show their results for Brinell hardness on the metals for which they published data. This is an exceptionally interesting phenomenon, if it occurs under all conditions of rolling, and would have an important bearing on the practice of cold

Jan 1, 1925

By K. V. S. Sastry

First attempts to apply computers for the modeling, simulation and analysis of mineral processing unit operations date back to almost twenty years. Since then substantial efforts have been directed to the development of computer software for mineral processing. Current literature indicates considerable activities in the development of computer packages for interactive and batch simulation of individual unit operations and integrated plant operations. This paper presents a comprehensive review of various simulation systems that have been described in the literature along with a discussion of present trends in the development of mineral processing simulation software. Finally, the paper includes a detailed discussion of the desirable features in future simulation packages.

Jan 1, 1984

By James Fiore

The Nuclear Waste Policy Act of 1982 provides a set of rules for proceeding with the identification and selection of sites for a mined geologic repository as well as for interim storage facilities for high level waste in the event storage facilities are needed. The following paper summarizes the sequence of procedures in site selection, and presents the interaction of governmental agencies, the states, the public, and affected Indian tribes in this process. Several agencies have published regulations assocated with the selection of high level waste sites. These regulations set down a diverse collection of requirements designed to ensure public safety. This paper identifies the organizations working to satisfy these requirements, and outlines the role of the geotechnical community in performing data collection activities to support these same requirements.

Jan 1, 1984

Jan 1, 1970

By Thomas W. Healy

Particles present in mineral processing systems that are termed ultrafine are those that are small enough to be unaffected by gravity or the flow conditions imposed on the pulp. As such, their interaction with one another and with other larger particles are controlled by specific attractive and repulsive colloidal or surface interactions. Electrostatic repulsion between ultrafines is dominated by surface potential, double layer thickness and specific adsorption potential effects - controlled by pH, salt and complexing ion concentrations. Attraction due to van der Waals interactions must be assessed in terms of bulk and surface coating effects and of particle size and shape. The net effect of attraction and repulsion must finally be related to the average kinetic energy of particles in the real system.

Jan 1, 1979

By B. Heide, A. Bergrnann

The Meggen mine and the concentrator plant of the Sachtleben Bergbau GmbH are located in the southern part of the Ruhr district of the Federal Republic of Germany. The mine has been in operation for more than 100 years, but the concentrator described in this paper was started up in January 1963. The Meggen orebody is of sedimentary origin and occurs in a zone of limestones, graywacke and shales of Devonian age. The average thickness of the deposit is 3 meters and due to an intense folding of the area, the mineralized zone dips steeply at 80º towards the north.

Jan 6, 1973

By N. J. Themelis

What is the "best" copper smelting technology? When a future Agricola examines the development of copper smelting in the 20th century, he will be amazed at how little took place in the first half of the century and how much in the second. In a period when the technology of transportation, communications and chemical processing advanced many fold, copper smelting remained practically static. The result of tightening energy supplies and stringent environmental controls in recent years has been a spate of development activity that not only is challenging the supremacy of the reverberatory furnace, but threatens to wipe out pyrometallurgical techniques entirely.

Jan 1, 1976

By A. W. Mitchell

Barite occurs as bedded and vein-type deposits in Nevada along a north-northeast trending zone that Parallels the Antler orogenic belt. The Nevada bedded deposits presently supply 85% of domestic barite production, used primarily as a weighting agent in the petroleum drilling industry. The ore bodies are controlled structurally and stratigraphically along regional and local structural breaks in siliceous eugeosynclinal rocks of lower to middle Paleozoic age. Evidence for the origin of the barite includes sedimentary and hydrothermal features, indicating that localization probably took place along fractures in the sea floor.

Jan 1, 1982

By S. W. Parr

STUDIES relating to the behavior of coal toward oxygen may have for their purpose the determination of the fundamental factors that underlie spontaneous combustion, weathering and deterioration, and the general topic of storage, as well as those properties that have to do with the underlying principles of carbonization. There is also involved the possibility of developing information relating to the constitution of coal, or at least the chemical properties inherent in the type substances of which the coal is composed. It is the purpose here to record certain FIG. 1. results bearing on this latter idea of the chemical properties that characterize the main constituents of bituminous coal. The avidity of freshly mined coal for oxygen has long been known. What happens to the coal or to the oxygen is not so clear. Is the oxygen absorbed or chemically combined, and what are the conditions as to time, temperature, texture, or components that are most involved in the phenomenon?

Jan 6, 1925

By E. D. Peters

The Sudbury ore-deposits possess a peculiar interest for a variety of reasons. In the first place, they are deep within the borders of the Huronian rocks, and are consequently amongst the oldest deposits that we know of, unless, indeed, the ores were deposited at a much later period than the country rock. Again, they carry nickel in unusual proportions, and lastly, they are unique in containing a small amount of platinum, although arsenic is not present. I shall not pretend to go into the geology of this region. The Huronian and Laurentian rocks are familiar to all American geologists, and these present only the usual series of gneiss, graywacke, quartzites, greenstones, clay-slates, etc., characteristic of this gigantic system of rocks, which has excited so much discussion of late years. As in all parts of Canada where it occurs, I believe, the rocks of this system are tilted to such an extraordinary degree that it may be said that the whole country is standing on edge at an angle of something like 70°. The general strike of these rocks is southwest

Jan 1, 1890