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Discussion of the paper of LAWRENCE ADDICKS, presented at the Salt Lake meet-ing, August, 1914, and printed in Bulletin No. 91, July, 1914, pp. 1671 to 1674. JAMES H. PAYNE, Baltimore, Md. (communication to the Secretary*). -Mr. Addicks's account of the behavior of the nodulizer at Chrome on blast-furnace flue dust leads me to outline what has been done so far upon the application .of the same apparatus to fine sulphide concentrates. As Mr. Addicks states in his paper, the conditions prevailing in the test kiln at Yorktown in the demonstration I made for him upon Chrome material were strongly oxidizing; so much so that the sulphur was roasted down to less than 1 per cent. It is therefore to be expected that the first test made upon sulphide ore a short time after this, in which Ducktown green ore fines were used, did not show very promising results. Although the Ducktown ore contained only 13.52 per cent. of sulphur its gangue was quite fusible, and the intense heat generated by the oxidation of. the extremely fine sulphide particles slagged the mass, bringing about a condition approximating that of a Brückner roaster in distress. During the spring and summer of 1912, the writer kept working upon different schemes to cut clown this slagging. Two successful methods were finally worked 'out embodying opposite principles, one promoting oxidation of the finer particles and the other retarding. their oxidation. In the early part of the present year the writer succeeded in interesting the Braden Copper Co. in nodulizing, with the result that an extensive series of tests were made at Yorktown upon oil-floated concentrates covering quite a wide range in analysis. These tests led to trials in the Chrome rotary on the part of the U. S. Metals Refining Co. of Minerals Separation concentrates which they had in stock, and later to test runs to check up the Yorktown runs on Braden concentrates. The large-scale tests checked up with the Yorktown tests in every way (except fuel consumption, which was, however, correctly predicted), and led to the Braden company's decision to adopt the process at Braden. The fuel consumption upon oil-floated concentrates is not over 6 gal. per ton and in many cases is less. The action in the furnace is independent of the sulphur content, and there is actually less tendency to form nose rings in the Chrome rotary than upon flue dust. It is believed that the improvements entering into the design of the Braden kilns will cut down the nose-ring trouble to where it will no longer be a drawback to the process.

Jan 11, 1914

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Jan 1, 1942

By McDowell Graves, Joseph Jensen, W. D. Goold, M. L. Gwin

During the present year the Santa Fe Springs field has proved to be the most important oil field under development in the United States. Its production will exceed that of any other field. Without it, production within the United States would have been almost in even balance with consumption. The field has forced to the fore and compelled, more than any other single factor, serious consideration of the need of conserving the gas resources of the State of California. It has also contributed much to the development of new drilling equipment and important features in petroleum engineering, and has required the development of a new cement for use in deep wells because of high temperatures. It is the only oil field in the country where wells 8000 ft. deep have become so common that they are no longer given special attention. The field covers a little less than 1400 acres of land. In it 196 producing deep-zone wells have already been drilled since August, 1928, and 224 wells are still drilling. More wells may be drilled. This indicates that probably more than 450 wells will be drilled in the present campaign. In hardly a year's time it has caused the outlay of nearly $50,000,000 for drilling, and within the year 1929 it will have returned practically an equal amount of revenue. In contrast to conditions during 1923, when this field was once before an important and disturbing factor, the California oil industry has not been forced to refinance to meet the situation presented by such a large production of oil. There has been practically no unit selling and no stock selling, nor any unnecessary development far beyond the limits of the field. Production is now about 275,000 bbl. per day and gives every promisc of remaining at this figure or increasing to nearly 300,000 bbl. Six months from now the field should still be capable of producing more than 200,000 bbl. per day. Obviously, the need for conserving gas that would be blown to the air, incident to the production of so large a volume of oil, represents a problem in conservation deserving of the most serious attention of the oil industry and of the State of California.

Jan 1, 1930

Jan 1, 1892

By James A. Burns

The challenge to designers of bulk materials handling systems is to apply the existing technology in areas where it has not been used and to foster better, cheaper and safer job performance. The Dashaveyor Co., a subsidiary of The Bendix Corp., built and tested a pilot system at Copper Range's White Pine mine. Based upon this success, a prototype system development was begun in 1967 to test the concepts in a full-scale, realistic environment.

Jan 11, 1973

By G. W. Hodges

The Basic Oxygen Process shop at Gary Works is a three vessel shop tapping 220 ton heats. The larger portion of the heats are teemed into ingot molds with the remaining heats being continuously cast in a single strand continuous slab caster. Ingot production includes a wide range of carbon, alloy, and high-strength steels in many ingot sizes for bar, structural, plate and sheet and tin products. Individual ingot weights vary with the number of ingots per heat ranging from a high of 48 to a low of five. Caster production is primarily Riband, a proprietary low carbon grade for sheet and tin applications developed by United States Steel for continuous casting; some Riband steel is vacuum degassed prior to casting. Maintaining a satisfactory level of ladle performance on both ingot and caster heats with a high production rate and widely varied product mix is a demanding and exacting job requiring the best of equipment, materials, and, most importantly, personnel. The improving trend in ladle performance in the No. 1 BOP shop at Gary is due to a combination of factors, which will be described in the following presentation.

Jan 1, 1972

By T. W. Healy, M. S. Moignard

The use of electrokinetic or zeta-potential phenomena in studies of the properties of mineral sulphides has increased greatly over recent years. This review aims to examine and discuss the body of literature on the subject of electrokinetic properties of sulphides in a comprehensive and critical manner. Although the review covers the period from 1925 to 1975, it is only in the past ten years that researchers have been fully aware of the implications and problems of chemical reactions, notably oxidation and precipitation reactions, on the surface properties of sulphide minerals. These papers are discussed in more detail than the earlier publications. A table containing a list of determinations of iso-electric- points and points-of-zero-charge of mineral sulphides, and the methods employed in obtaining these results, is presented.

Jan 1, 1976

By P. L. De Bruyn

The behavior of collectors at the mineral-solution interfaces is usually explained in terms of an ionic adsorption process. Through the distribution of collector ions between the solid surface and the co-existing solution phase the mineral is believed to acquire a water-repellent surface coating. Quantitative adsorption studies have been made on simple flotation systems only within the last few years. Such investigations were made possible by the adoption of the radiotracer method of analysis. As a consequence of these studies a new parameter has been added to aid the understanding of the flotation process.

Jan 3, 1955

By Bruce H. Gardner, Stephen A. Miller, Shosei Serata

The Bryan Mound salt dome in Freeport, Texas, has some of the largest and oldest solution caverns in the U.S. There are a total of five caverns of varying shapes and sizes randomly distributed throughout the salt dome. When the caverns were converted from a brine production to an oil storage operation, the effects on long-term stability of the caverns and inter-cavern behavior were analyzed to evaluate the future safety of the storage operation. The analysis was based on a worst-possible-case scenario, including accidental wellhead pressure loss. The impact of this pressure loss upon the thinnest partition between the two closest caverns was analyzed, using a case example of storing lightest weight LPG, thereby creating maximum differential pressures between these two caverns. The finite element method with the REM computer code was utilized for this analysis. Results of the analysis illustrate the basic mechanisms of the long-term behavior of the multiple caverns in the LPG storage operation.

Jan 1, 1985

By Lloyal O. Bacon

In the spring of 1952 Calumet and Hecla Inc. began a geophysical program near Shullsburg, Wis., in the Wisconsin-Illinois lead-zinc district, to assist the geological and drilling exploration programs. Sphalerite, the ore mineral in this area, occurs with a considerable amount of marcasite. In general the higher the percentage of sphalerite in the ore, the higher the percentage of marcasite; however, there may be mineralized zones high in marcasite but low in sphalerite. Orebodies in general are relatively narrow and elongated.

Feb 1, 1956

By Zden[e]k P. Bažant

Due to their heterogeneity, most rocks fracture with a zone of distributed cracking ahead of the fracture front. This makes linear elastic fracture mechanics inapplicable. The present study describes a mathematical model in which the progressive microcracking is taken into account by strain-softening stress-strain relation. In a simpler version of the model, the triaxial strain-softening stress- strain relation is obtained by direct adjustment of the elements of the compliance matrix. This formulation is rigorous only if the principal stress directions do not rotate during fracture formation within the fracture process zone. As a more sophisticated and generally applicable model, the so-called microplane model which is an analogue of the slip theory of plasticity is outlined. Comparison with fracture data for various rocks are given.

Jan 1, 1984

HENRY FAY, Cambridge, Mass. (written discussion *).-Mr. Rawdon has made a distinct contribution to our knowledge of wrought iron, and .perhaps of steel. It will undoubtedly lead to more careful scrutiny of high-phosphorus steels, with perhaps important results. In view of his results, it would seem to be unprofitable to push further any propaganda on the use of higher-phosphorus low-carbon steels until further information is available. As is well known, and as Mr. Rawdon clearly shows, the process of solidification is a selective one, and there is abundant opportunity for those portions of the melt last to solidify to become rich in phosphorus, and the diffusion of this phosphorus-rich area is slow. Hot work does not help the situation appreciably and only serves to concentrate the low-melting material. It is undoubtedly true, as some writers have recently claimed, that the specifications for steels as they. now exist eliminate some perfectly good material. Higher phosphorus in steel may be perfectly safe provided all of the phosphide is completely and uniformly, diffused in the solid solution. If, on the contrary, it is not evenly diffused, and there is a reasonable chance for it not to be, it makes the steel unsafe. Until our knowledge: of the rate of diffusion of phosphorus in steel, and the effect of other elements upon the rate, is more complete, it seems to me unwise, in view of Mr. Rawdon's experiments, to listen to the recommendations for the use of higher-phosphorus steels.

Jan 1, 1918

By John J. Childress, Russell L. Cook

Stringent environmental regulations, which have limited the use of sludge ponds, coupled with the economic incentive to clean more coal or to add fine coal cleaning additions to existing preparation plants have increased the use of static thickeners in preparation plants. The Lamella Gravity Settler, sometimes designated Lamella Thickener, is a shallow depth sedimentation device which has been applied in a variety of industrial process and wastewater control projects in place of the conventional raked thickeners. This paper presents the theory and design of the Lamella Thickener, as well as describing the operating results from several full scale installations in a variety of Appalachian preparation plants.

Jan 1, 1979

By George Burgess

NOTE BY THE EDITOR.-This resume of a Technologic Paper which is published in full by the U. S. Bureau of Standards, is brought before the membership of the Institute with the object of affording an opportunity for the open discussion of results of an investigation by the authors named above, of some phases of the manufacture of steel rails which are of great importance to manufacturer and consumer alike. This resume will be presented at the Pittsburg Meeting of the Institute. Discussion is invited, by either members or non-members of the Institute. The discussion may be sent in writing to the Editor, in advance of the meeting, or should preferably be presented in person at the meeting. To those who desire to discuss, copy of the full Technologic Paper (No. 38), as published by the Bureau of Stanaards, will be sent upon request addressed either to the Bureau of Standards, Washington, D. C., or to the Editor, American Institute of Mining Engineers, 29 West 39th Street, New York, N. Y. Summary of Researches and Conclusions The main objects of this investigation were to determine, from measurements taken at representative rail mills, the present American practice regarding the temperatures at which rails are rolled; to demonstrate the ease and accuracy with which such temperatures may be measured, without interfering in any way with the manufacture of the product; to find out what the "shrinkage clause" in rail specifications really means; and, finally, to determine some of the physical properties of rail steels, particularly those of interest in manufacture, some of which seem to be insufficiently known as yet. 1. Ingot Temperatures.-Measurements made in four mills show that ingots for rails are rolled at temperatures ranging from 1,075° to 1,150° C. (1,965° to 2,100° F.), and that, in a series of 20 to 40 ingots, the variation in temperature from one ingot to another is only 10° to 20° C. 2. Finishing Temperatures.-Rails are finished at temperatures ranging broadly from 880° to-1,050° C. (1,615 to 1,922° F.), but usually ranging within 50° C. of 935° C., and occasionally above 1,100° C.

Jan 9, 1914

By Thomas Fraser, Robert MacLachlan

The dry cleaning of coal is a relatively new art and, as might have been expected, a number of unforeseen problems have been brought to light in the few years that dry methods of treatment have been in commercial use. The pneumatic concentrators that were first adapted to the cleaning of coal had already been developed to a fair degree of efficiency, although at low ratings, in the field of ore dressing. The concentrating machines, therefore, were in a relatively more perfected state than the general technology of dry cleaning and, for this reason, the major difficulties encountered in the early plants were in the accessory operations involved in the servicing of the cleaners rather than in the functioning of the cleaners themselves. The crudities of a new technology were further aggravated, in some cases, by meagerness of appropriations which precluded even the provision of adequate storage bins and such other facilities as had been long recognized as indispensable to the proper functioning of older types of cleaning plants. The practice of dry cleaning is now sufficiently established so that we may examine critically auxiliary equipment and operations. The cleaning processes have been so simplified, with respect to presizing of the raw coal required and the quantity of air circulated, that stinting of expenditures for auxiliary equipment is not necessary to keep the per ton cost of installation in line with complete and well designed plants of other types. Furthermore, sufficient operating experience has been accumulated to ascertain the conditions most conducive to effective operation of dry-cleaning machines; at least the essentials of a definite technology of dry cleaning has been established. Early Operating Problems The problems that have occupied the builders and operators of dry-cleaning plants from the beginning have been relatively few, but difficult of solution. The principal difficulties have been: 1. The proper sizing of the raw coal to suit the cleaning process. 2. The handling of raw coal when it is delivered wet from the mine. 3. Dust collecting. 4. The maintenance of uniformity in cleaning performance.

Jan 1, 1931

By Milton E. Wadsworth, Edward M. Eyring

Better understanding of solid surfaces and their associated adsorption products is of both academic and practical value. The study of detergents and their behavior in cleaning surfaces is fundamentally related to the nature of the products adsorbed and their ability to compete for certain surfaces. Similarly in flotation, the nature of the adsorbate before and after adsorption is basic to clear understanding of the process. The recently developed pellet technique employing infrared spectroscopy provides a powerful tool for the study of solid surfaces. Absorption bands, which are infrared-active, may be observed for adsorbed products. Also any changes in the surface substrate that occur as a result of adsorption may be detected by means of differential spectra

May 1, 1956

By Richard Maclin Stewart

A priest at Shenandoah, Pa., one day persuaded the president of the Philadelphia & Reading Coal & Iron Co. to slush breaker waste and culm into old mine workings in order to save his church from being destroyed by surface subsidence. The year was 1864, the project was successful, and history recorded the first use of hydraulic backfilling. Shortly afterward, the method was applied to several eastern coal mines for area fill to control subsidence. In 1884, hydraulic backfilling was used to control a mine fire in the Schuylkill region of Pennsylvania. The idea was taken to Europe by German engineers and developed successfully at the Myslovitz colliery in Upper Silesia in 1901. From there it was applied to several mines throughout Europe.

Jan 4, 1958

By Stephen E. Merritt, John W. Straton, T. Carl Shelton

Surveying and mapping are used to locate and visually portray objects, lines, or areas in relation to a reference point or line. The actual making of the measurements to locate the objects and points falls under surveying while mapping is concerned with putting the survey information into a graphical form. Generally, the type or class of proposed survey depends on the precision required. Some surveys may need only approximate measurements which can be obtained by simply pacing or by using an ordinary measuring tape; others may require much accuracy, thus calling for the use of an engineer's transit or theodolite along with a graduated steel tape for horizontal measurements, or a level and a graduated rod for measuring vertical distances. Mapping is likewise dependent on accuracy requirements. For example, a general layout showing the relative position of surface facilities may not call for a large scale of dimension or great precision whereas for detailed work, a large scale plus care in plotting points and drawing lines and curves are important factors. SURVEYING METHODS There are many kinds or types of surveying methods. Some examples include : land surveying for determining boundaries of land areas; route surveying for locating roads, highways, right-of-way, and haulways; city surveying for laying out lots, streets, and alleys; and mining surveying for projecting mine openings and locating mining operations. See Fig. 1. There are other types of surveying than those named, but in general, the type of method to be used will depend on the purpose for which the survey is to be made.

Jan 1, 1981

By E. C. Weichel

THERE have been many attempts at permanent roof support in anthracite mines, in some cases brick arches, in others concrete, and also combinations of brick or concrete walls with steel beams. These supposedly permanent roof supports have frequently failed when heavy pressure is brought to bear upon the structure, because they are so rigid that failure occurs because the structure is unable to adjust itself to the increased load. Roof pressure exerts a tremendous weight, and it is at times difficult to find any means of support which is strong enough to bear the entire pressure, unless this supporting structure has in itself the element of some flexibility which will enable the structure to hold the moving mass until it "arches" itself. If the supporting medium has flexibility enough so that it can adjust itself to the heavy initial loads, and so give the overlying material an opportunity to form a self-supporting arch, then such a roof support will be more useful than any rigid roof support. There has recently been introduced into the anthracite region a new form of gangway lining that is flexible enough to slightly adjust itself under heavy pressures, and so give the loosened material which is being supported a chance to form into an "arched" mass. This lining, manufactured under patents granted to Hans Schaefer of Essen, Germany, was introduced in the United States in the summer of 1928, at which time the Amercan licensee, Richard Howells of

Jan 1, 1930

By Carroll Wegemann

THAT Colorado was producing oil and gas before the fields of the Mid-Continent were discovered is a fact too frequently overlooked. As early as 1862, oil was obtained in the Florence district (see Fig. 1) from seepages and shallow holes. The first well that could be regarded Fig. 1. as being truly commercial was drilled in this field in 1876. The field is now producing 100,000 bbl. per year, and is credited with a total production of approximately 11,000,000 bbl. The small field near Boulder, Boulder County, was opened in 1901; production has now practically ceased but the field is credited" with a total production of 610,000 bbl. Oil was discovered at Rangeley in 1901, and the field supports a small local refinery at the present time. The first shallow well in the White River gas field was drilled in 1892, and the wells now producing have been

Jan 3, 1925