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By AIME AIME

A MODERN copper reduction works has both a genera1 chemical laboratory for control work and a research laboratory for the study of improvement of present processes and better working-up of by-products. The division of work in the general laboratory would naturally differ in different plants. The following statement to the writer from a chemist in one of the works will give a good idea of the type. of work in the general laboratory :

Jan 1, 1929

By J. B. Newsom

IN the September 1936 issue of MINING AND METALLURGY the pioneer work of boring a 5-ft. shaft to a depth of 1125 ft. at the Idaho Maryland mine in California was described. Later, a Bureau of Mines Information Circular (No. 6923) gave additional data. In re¬cent months still further progress has been made in this technique through the sinking of a 5 1/2-ft. shaft for Pickands, Mather & Co. at their Zenith mine, Ely, Minn. The present work was done with new carefully designed equipment and several experienced men so that progress, as shown below has been much better:

Jan 1, 1938

By AIME AIME

IN RESPONSE to a request from the president- elect of the Institution of Civil Engineers of Great Britain, Mr. Calvin W. Rice, secretary of the American Society of Mechanical Engineers, prepared a brief history of the joint activities of engineering societies in the United States, from which we have taken the following facts. National Societies Our first joint activities were in collection with the celebration of the eightieth birthday of "Uncle John" Fritz in 1902, and it is of interest to note that two of the members of the original celebration committee, Messrk. . Ambrose Swasey and Jesse Merrick Smith, will be members of the official deputation to England in June. Mr. Rice, also,' was .a member, of the original committee.

Jan 1, 1921

By Edwin Ludlow

To THE members of the American Institute of Mining and? Metallurgical Engineers who were fortunate enough to be able to attend the Fiftieth Anniversary at Wilkes-Barre, it was brought home that commercial anthracite requires not only expensive mining but that the milling or preparation of it is also a costly operation, requiring very large capital expenditures and high maintenance and labor costs. The great trouble that coal men meet in discussions of coal problems today is the difficulty the average coal user, especially in the East, finds in distinguishing between anthracite and bituminous coals. They are two entirely separate problems and yet the people who are burning coal complain bitterly of the high cost of anthracite and quote the figures furnished in regard to the prices of bituminous coal and feel that the anthracite operators are making an excessive profit, without realizing the enormous difference in the cost of production in the two fields. The great difference that can be marked is that in this year of industrial depression the prices of anthracite have been not only maintained but have increased during the summer, while the price of bituminous coal has been continually dropping since the first of the year, and yet the same law of supply and demand governs both anthracite and bituminous. In order to understand the situation the two problems must be considered from their separate points of view.

Jan 1, 1921

By Walter S. Tower

IN making comparisons of steel industries, one country with another, the convenient common denominator is annual capacity to make raw steel in the form of ingots. It is always necessary, however, to remember that there are different methods of figuring such capacity. For most countries no official figures on capacity are available, and the only authentic data on production are now six or eight years old. But in spite of those limitations on the accuracy of statistical comparisons, any flaws in the figures are probably not serious enough to alter materially the larger conclusions which may be drawn from them.

Jan 1, 1944

By Frances H. Clark

DEVELOPMENTS in powder metallurgy have been disappointing in 1943. If any new part has gone into large-scale production, knowledge of it has been restricted by considerations of national security. Nor have any outstanding papers appeared to advance the theory of the subject during this period.

Jan 1, 1944

By E. W. Enqelmann

DURING January, 1933, burlap or coco matting was placed in the bottom of launders handling various products of the flotation plant of the Magna mill of the Utah Copper Co., with the hope of increasing the total recovery of gold. This was soon followed by placing various materials, such as coco matting, cotton twill, and common 10-oz. burlap on the bottom of the main tailing launder. The burlap was found to be the most economical material to use. The test was first conducted in an old wooden launder, 40 in. wide and 2000 ft. long, with 10-oz. burlap fastened

Jan 1, 1935

By AIME AIME

THIS year the Petroleum Division holds its fall meeting at Houston, Texas, Oct. 2 and 3, with head- quarters at the Lamar Hotel. Technical sessions will be held in the morning and afternoon of both days. A smoker on Friday afternoon will afford an opportunity to get together socially. Saturday evening is left free for private parties to the beach at Galveston, where a wide variety of entertainment is available. On Oct. 4 there will be an excursion to Sugarland oil field, with luncheon at Boling and a visit to Boling sulfur mine and plant in the afternoon. There are nine technical papers on the program for Friday. Saturday morning will be devoted to oil production control and it is planned to make the discussion more

Jan 1, 1931

By W. M. Raynor

LARGE quantities of "midnight oil" have been consumed by researchers in attempting to develop a process to produce cold ductile zirconium at low cost. The tantalizing facts that zirconium is a bright, silvery, tarnish-proof metal and is 2 1/2 times as abundant in the earth's crust as copper, and thirteen times as plentiful as lead have resulted in much speculation on uses, ranging from automobile radiator grills to kitchen sinks. but unfortunately no low-cost process of producing it has so far been found. In the case of zirconium, we cannot say that "virtue is its own reward" for the principal virtues of the metal, namely, corrosion resistance at ordinary temperatures and ability to absorb gases at high temperature, are the very characteristics that defeat all of the usual recovery methods such as sintering, plating, or direct chemical reduction. The only method giving a pure metal sufficiently low in oxides, nitrides, etc. to be truly cold-malleable is the one developed by Van Arkel and DeBoer in 1925. This process involves decomposition of zirconium tetraiodide in contact with a hot filament and pre

Jan 1, 1947

By AIME AIME

THE non-ferrous alloys have been placed in the same class with steel by metallurgical research on hardening, and hardenable alloys of all metals except zinc are now manufactured. The hardening of the non-ferrous alloys is accomplished by a process of heating, quenching and ageing. R. S. Dean, head of the research department of the Western Electric Co., told of the results of this research in 'a lecture on "Recent Advances in the Art and Science of Fabricating Metals," given before the Missouri Mining and Metallurgical Association on Jan. 24, 1929.

Jan 1, 1929

JamEs F. Kemp, New York, N. Y.:—Mr. Hewett's paper is one of exceptional interest, because it not only adds an important contribution regarding one of the rarer, valuable elements, but also because it introduces compounds hitherto unknown and in associations no less novel. While we have occasionally discovered and recorded asphaltite in metalliferous deposits, for example in the Joplin and Granby districts, we have not seen a metallic ore in a deposit eesentially asphaltite. The source and method of introduction afford a subject well worth serious reflection.

Jan 1, 1910

HeRbert A. MeGRaw, San Luis de la Paz, Guanajuato, Mex. (communication to the Secretary*) :—Although Mr. Bordeaux prefaces his paper with the statement-that it is a general outline of practice in the Republic, many of his statements seem to be made from the view-point of a particular case, which does not always agree with general practice. For the purpose of calling attention to some of these variations, I respectfully offer the following comments: The operation of crushing and grinding is performed by so many different methods and systems that it is useless to select any one as the standard. However, primary crushing in rock-breakers followed by stamps is thus far so general that it might be so classified. Whether or not it is the best way, is open to question. Regrinding may be performed by any of the various types of Chilean mills, Huntington mills, or similar machines, or the material may be taken directly from the stamps and delivered to the tube-mills. Mr. Bordeaux's statement that " the slimes can be treated only by decantation; the new Butters slime-filter, as used in Nevada, does not seem to be successful with silver-ores," is surely an error. All over Mexico many of the purely silver-ores are being successfully handled by the Butters or similar filters, such as the Moore and the Burt filters, and a letter to the manufacturers of these filters will undoubtedly bring a list of the silver-ores now being successfully treated in this way. The statement that crushing silver-ores in solution is impossible is equally erroneous. Most modern mills crush the ore in solution, in some cases containing as much as 0.12 per cent, of KCN. I cannot for the moment recall any modern mill in Mexico which does not follow this practice. There may be some reason for it in particular instances, but, generally speaking, the practice is to crush in solution. Care in installation avoids any mechanical loss of cyanide, and the chemical loss is so small as to be negligible.

Jan 1, 1910

Allan Gibb, Queensland, Australia (communication to the Secretary*):—It is gratifying that Mr. Edward Keller,' who has clone so much work elucidating the principles of copper-metnllurgy, should have subjected only that portion of our investigation relating to magnetic iron oxide to anything like adverse criticism. Situated as we were on a rnining-camp, it was impossible to undertake work that would cover all the intricate possibilities connected with the materials commonly classed as matte. We therefore began the investigation on matte produced from ores that contained no other components than the sulphides of copper and iron that would be likely to enter into the composition of matte. We were, accordingly, free from ally possibility of magnetic iron oxide entering the matte, unless it were formed in the operation itself. The work done on this subject was incomplete, and the results thereof recorded as giving only negative evidence as to the absence of magnetic iron oxide. It would have been better to have left the matter open, as " not proven." The trend of the investigation was to account for the insufficiency of sulphur in matte to satisfy the requirements of ferrous and cuprous sulphides. So far as our deductions are correct, it was unnecessary to consider the (in our samples) somewhat doubtful constituent, magnetic iron oxide. The mattes that mere investigated were among those mentioned by Mr. Keller, " which scarcely show ally magnetic property." The samples showed no such property. There was no unaccountable variation in the specific gravity, which only varied, as would be expected, with the proportion of ferrous sulphide. I have had experience in smelting ores of which the gangue was a siliceous magnetite, both in blast- and rever-beratory furuace. The mattes so produced contained magnetic

Jan 1, 1908

David T. Day, Washington, D. C.: The paper of Mr. Adams is chiefly valuable because it emphasizes the ease with which petroleum can migrate in the earth's crust. Concerning this migration, I have little faith in the rôle of water as a carrier of gaseous or liquid hydrocarbon, suspended or mixed in the water in any way. My lack of faith is due to observation of

Jan 1, 1903

The world's largest steam-driven mine hoist, built by Nordberg Manufacturing Co. a half century ago, has become a major tourist attraction in Michigan's Upper Peninsula. The hoist, designed by company founder Bruno V. Nordberg, is located in the Quincy Mine Number Two, just north of Hancock. Nordberg began construction of the mammoth machine before World War I, but delayed completion until after the war. The hoist became operational in 1920 and continued running until the mine was shut down in 1931.

Jan 9, 1968

James Gayley, Braddock, Pa. (communication to the Secretary) : Mr. Potter has made reference to our practice at the Edgar Thomson works in the direction of increasing the life of the lining, and mentions the product of one of our furnaces as having reached a total of 370,000 tons. It may be interesting to know that this furnace has been put out of blast with a record of 452,685 tons, after a run of three years and nine months. A companion-furnace to this will produce, hefore the present year is ended, half a million tons. As Mr. Potter has quite correctly designated this as " the newest problem in furnace-practice," a description of the construction of this furnace lining may be Welcome to members. The bricks used in the lining are 9 and 134 inches long, with the requisite quantity of straight and key-shapes to turn the circle. There bricks are well suited for enclosing the numerous bosh-plates used for cooling. The bosh-plates (the efficient fortress of the lining) extend from the top of the tuyere arch to the mantel, and are inserted in rows, 18 inches to 2 feet apart. These form a perfect defence against encroachment on the bosh-lining, and leave the bosh at the end of the blast of the same thickness as at the beginning. The protection afforded by these bosh plates is the principal cause of the increased duration of the furnace-lining. But it must be noted that the shape and material of the plate are essential elements. The most serviceable plate is that made of bronze or copper. We have tried every form of iron plates without obtaining satisfactory results. These were replaced with bronze plates, built into the lining, which gave excellent results so long as they did not leak; but when this occurred, as it did in time, the water was shut off, and, since the plates could only be removed with difficulty, they were allowed to burn off. This permitted encroachment on the bosh-walls, which thus became enlarged beyond the limit required for economical practice. With the introduction of the removable plate, made tapering on the sides, with plain surfaced top and bottom, these troubles have

Jan 1, 1895

By Freeman Bishop

Having obviously cleared the way for fast confirmation by the Senate Interior Committee, the Administration recently named Elburt F. Osborn, vice president of Penn State University, as director of the Bureau of Mines. Interior Committee Chairman Henry M. Jackson (D of Wash.) has moved hearings on the nomination right along, forecasting that they will end in a confirmation. Dr. Osborn not only made a good impression on the Committee, he also made it amply clear that he would be the boss of his job and have right-hand aides to help straighten out conflicts stemming from recently enacted health and safety regulations for miners. Mining engineers in the field hope this clarification can come soon. They are frankly fed up with local, state, regional and national overlapping of restrictions.

Jan 1, 1970

By Frank Firmstone

The material described below was made at Furnace No. 2, Longdale, Va., Oct. 28, 1907, during a sudden derangement of working, in the course of which the furnace became entirely bridged over and for some time no solid material whatever descended into the hearth. This caused the hearth to become so completely emptied that, at the tuyere-level, a pricker put in at one tuyere could be seen by looking in at the opposite one. The tap-hole was opened and the iron got out with some difficulty. It ran sluggishly, throwing many sparks, but was not too thick to run into the chill-molds. Naturally, the product was assumed to be white iron, which is almost always produced under similar circumstances; but on removal front the molds it proved to be very strong and tough, although full of blow-holes. Most of these blow-holes bad bright, unoxidized walls. The iron could be drilled by using a "special steel" drill, the drillings curling up similarly to those of steel. An analysis by P. W. Shimer of this unusual product gave: Si, 0.019; P, 0.228; S, 0,39; Mn, 0.042; C, 2.366; and graphite, 0:000 per cent. A cast of iron made just before the disturbance contained P, 0.98, and Mn, 1 per cent. The peculiar product seems to have been decarburized in the hearth and, at the same time, to have lost much phosphorus and manganese, either by the action of the blast in the empty hearth, or, more probably, by. contact with the cinder rich in iron which was formed at the time. Unfortunately, no specimen of the cinder was preserved, so its composition cannot be given. It seems very remarkable that, with the furnace in bad condition, the temperature should be high enough to keep such

Sep 1, 1908

K. W. Turner, Sail Francisco, Cal. (communication to the Secretary*): The recent papers in the Transactions by Vogt,' Lindgren2 and Weed: on ore-deposits that have formed as a direct result of igneous intrusions, show that deposits of this class are widely distributed over the world, and are occasionally of commercial value. This is especially true if we consider under this head all deposits in the zone of contactrnletamorphism, the origin of which may be ascribed to the gases and vapors generated by the heat of the intrusive rock. Mr. Smith's description of the Chillagoe garnet-formations containing copper, leads one to regard these depoaits as of contactrmetamorphic origin, although he gives certain reaeons for supposing them to be of igneous origin.

Jan 1, 1904

By C. T. Holland

This discussion is concerned with those com-J- paratively infrequent bumps that eject material from the failed mass with enough energy to wreck heavy machinery and seriously injure or kill people. In such cases there is a loud report, and the pressure waves set up in the mine atmosphere wreck ventilation controls several hundred feet from the site of the failure. Vibrations are induced in the earth's crust which may be detected several miles from the point of origin, and explosive gases may be released in large quantities." Usually a dense suspension of dust is produced from the failed mass, together with dust placed in suspension by the resulting air blast. These rock bursts or bumps have also been called mountain shots, bounces, pillar bursts, and crumps. Such occurrences, when extensive, are serious catastrophes, and may force abandonment of the mine.' CAUSES OF ROCK BURSTS Rock bursts in coal mines have occurred in sev-eral places under diverse geological conditions, mining methods, and/or practices. A study of many such occurrences indicates that they depend on the following conditions: 1) cover thickness of 500 ft or more, 2) cover composed of strong members and having a strong member lying close to or on the coal bed, and 3) a floor that does not readily heave. The minimum thickness of cover under which coal mine rock bursts occur is based on observation. Under unusual circumstances involving very strong roof members and/or mining systems, and/or practices especially likely to induce bursts, a burst conceivably could occur under less roof. Under special circumstances rock bursts have occurred in marble quarries almost at the surface.' Furthermore, under very heavy cover it is likely that controlling roof members need not be as strong and as close to the coal bed to cause bumps. Just what constitutes a strong roof or roof member is open to question. Obviously the strength of a roof member is determined by its thickness, the distance between bedding planes across which little or no bond exists, the spacing and development of joints, and the inherent strength of the rock material. Strata sections showing roofs under which rock bursts in coal mines have developed are illustrated in Fig. 2. In several instances the strength of rocks composing the roof of mines developing bumps has been tested. The tests (Table I) show that these rocks develop considerable strength in compression, bending, and shear and that in some cases the strengths are very high. No quantitative data are available concerning joints in roof members over coal beds where rock bursts have occurred, but the author has examined many mines subject to bursts and has received the impression that joints in the shales immediately over the coal beds are always present and well developed. In the main sandstone or conglomerate members themselves, however, where observed, he has yet to see a fracture system indicating well developed joints. Undoubtedly joints are present, but the evidence indicates that they are few, poorly developed, and widely spaced. In a mine subject to bumps, moreover, actual measurements of roof spans up to 225 ft between supports under a cover of about 800 ft have been made before roof failure occurred. Such spans signify strong roof. In coal beds subject to rock bursts, the bottom rock is usually a sandy shale. A few tests (Table I) have been made on the floor rock of coal beds. Observations in mines indicate that they are usually weaker than roof rocks and that under load they show more plastic effects. Observation in ground subject to bursts invariably indicates a relatively strong floor highly resistant to heaving, although some heaving may occur. Other factors listed as favorable to rock bursts are: 1) mountainous surface; 2) steeply dipping beds; 3) proximity of faults, folds, and other similar geologic structures. Many bursts have occurred in mines under mountainous country, although many bursts in mines under a surface with little relief indicate that thickness of cover, not relief, is the essential factor. In steeply dipping beds, many bursts occur in mines that are essentially flat, and rock bursts have been recorded in beds dipping as much as 35o Most rock bursts in the U. S. occur in beds that dip less than 10 pct. It is also true that most U. S. coal is produced from beds dipping less than 10 pct. Geologically, faults are regarded as providing stress relief, but in the vicinity of faults, as well as sharp folds, it would seem that residual stresses could be present. The fact that rock bursts occur in areas remote from faults and sharp folds suggests that their presence is not necessary for this phenomenon to take place. There have been many bursts close to faults and folds, and it may be assumed that occasionally such structures accentuate their occurrence3 The conditions and circumstances under which they occur, coupled with the effects produced, leave In the Crowsnest Pass coalfield, British Columbia, a rock burst is estimated to have released 1.8 million cu ft of methane.

Jan 1, 1959