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Discussion o f Papers. Meetings of the Institute offer opportunity for social acquaintance and exchange of ideas, for the--presentation of papers, and-for discussions. thereon ; also incidentally for viewing under especially favorable conditions mining operations and industrial establishments, and for hospitalities which demonstrate the brotherhood clue to kindred interests. Placing sociability prominent is not to be assumed as relegating other features of meetings to subordinate positions; but during about 40 years of membership in the Institute, the value of acquaintances formed (often ripening into close friendship), and the interchange of data, have frequently demonstrated that the social feature of meetings is of great and lasting value to the membership. Of a roll embracing 4,011 members, resident in all parts of our country, and scattered in various portions of the world, only a small fraction are able to attend meetings, even if the localities selected are alternately widely separated. Hence, the return which most members receive for their annual assessment of dues is limited to the publications issued, and the credit of being recognized as a. member of a great and worthy organization. The greater the value of the contents of our publication, the fuller the return which goes to members. While the Institute disavows responsibility for views or statements made ill papers which appear in its Transactions, the fact that these contributions, after passing proper censorship, are accepted by the Institute and spread before the world may properly be received by the writers as endorsements of their (the writers') ability to present a specific technical or industrial proposition worthy of being carefully read. But the mere presentation and publication of contributed papers falls short of fulfilling one important feature of our meetings. If the purpose is confined to having the writers' views, discoveries, theories, or methods published, this can be obtained through the technical or trade journals and magazines. The true value of a paper presented at a meeting of the Institute may often be gauged by the discussion which it encourages, although there are contributions of decided value which do not especially invite discussion. However, most Of the papers offered contain statements apt to encourage criticism or elaboration by others whose experience or knowledge, or both, assist in combating or endorsing statements made.

Jan 7, 1913

By E. DeGolyer

PROSPECTING for new deposits is a part of the ordinary routine business of the petroleum industry to an extent that is not true for any other mineral industry. The health of the industry depends upon whether we are successful or unsuccessful. How many know what it costs to find oil today and what it has cost in the past? Very few, I will wager. The industry is not well informed upon this extremely important point. We cannot deal in averages for lack of information. Does it cost more or less than previously? Prospect wells are increasingly deeper and, since the introduction of the core drill, prospecting techniques have required increasingly expensive field oper-

Jan 1, 1939

By F. C. Blare

THE best method for the estimation of copper in ores and secondary products is that proposed by Dr. Steinbeck* for the award offered by the Mansfeld'schen Ober-Berg-und Hutten-Direction. It is based upon the decolorization of the blue ammonia solution of copper by potassic cyanide,† It is necessary for the accurate estimation of copper in arsenides that the arsenic be separated from the copper before the ammonia solution is made. The presence of a notable amount of arsenic renders the titration by potassic cyanide inaccurate, the end reaction being obscured by the appearance of a yellowish-green tint towards the end of the titration. The change of the color of the ammonia solution from blue to the tint caused by the presence of arsenic cannot be used for an end reaction, for the intensity and quick appearance of the latter-color depend upon the amount of arsenic present in the solution. In the analysis of speise, the method of separating the copper by an oxidizing and reducing treatment in the muffle, to volatilize the arsenic, gives poor results, and there may easily be some loss of the weighed sample. The separation of the precipitated sulphides of arsenic and copper by treating with sodic sulphide, gives good results, but the process is tedious. I have used the two following methods, which are simpler and more expeditious than those mentioned, with good results. * Fresenius, Zeitschrift Air Anal. Chemie., viii, 1. †First noted by Parkes in the Mining Journal for 1861.

Jan 1, 1881

By P. Barnes

SEVERAL interesting and important considerations may be based upon an analysis of the cost of producing Bessemer rails, and the facts thus set forth may be much more clearly emphasized by reducing each item of cost to its own fractional proportion of the sum total in each branch of the manufacture. The estimate given below is not absolutely complete in minuteness of detail, but it may be fairly taken as a basis for the suggestions to be noted : Perhaps the most striking comments that can be made upon this statement are those arising from a consideration of some of the smaller items, and even the least of these quite loses its insignifi¬cance when its proportion of the whole is expressed in actual money, as for the work of a year, or even for a single day. Thus, if the item A 5 be considered, the importance can be clearly

Jan 1, 1877

By N. B. Wittman

Among the objects of interest which the members of the Institute are invited to examine in connection with this meeting is the Brown segmental wire-gun, which will be seen in process of construction at the works of the Pennsylvania Diamond Drill and Manufacturing Company, at Birdsboro. This is a 5-inch breech-loading (highpower) rifle, 19 feet long, constructed upon the system of Mr. J. H. Brown, an inventor of recognized genius in many branches of mechanical industry, and under the engineering direction of Lieutenant G. N. Whistler, Fifth U. S. Artillery. The system consists essentially of the subdivision of the inner core or tube of the gun, which takes up the initial compression, into longitudinal segments of such size that a higher physical condition and degree of special elasticity may be set up therein than it is possible to produce in the larger masses of metal heretofore used for the tube of the modern high-power cannon. The process consists in winding layers of square steel wire, subjected to a constant tension of 130,000 pounds per square inch, around these segments, which, when so held together, form the tube of the gun. A lining-tube may or may not be used. The steel segments used in the gun now under construction are 18 feet 4 inches long, and 3 inches thick at the breech, from which they taper to 0.8 inches at the muzzle. The physical condition of the segments has been determined by test-pieces, cut from each end of each segment, which show the following characteristics: Tensile strength, 165,000 pounds per square inch. Elastic limit, 105,000 pounds per square inch. Elongation at rupture, 14 per cent. in 2 inches. They are of crucible chrome steel, made by the Carpenter Steel Works, at Reading, Pa. The wire which holds them together has 0.005 square inches sectional area and is wound under a constant tension of 650 pounds on each strand, equivalent to 130,000 pounds per square inch. The winding has been done by a machine designed

Jan 1, 1893

By F. L. Grammer

In these day, when anthracite is less extensively used as a blastifurnace fuel than it was a generation ago, and managers endeavor to maintain regular and known ore-mixtures, the " freezing " of tuyeres, cinder-notch or iron-notch is infrequeut; and, consequently, the oil-burner or " kerosene blowpipe "* is seldom employed; and furnace-foremen have, to a considerable degree, forgotten their former cunning and persistency in the use of the drill and sledge. Still, in starting new or abandoned plants with untrained labor, and in running some of our large 100-ft. furnaces, slips, resulting in very cold furnaces, may occur, even under experienced managers. During my superintendence of the Cleveland, O., blast-furnaces, such a misfortune, owing to a dearth of trustworthy foremen, was experienced; and our electrician, Mr. Thomas Martin, proposed to open the tuyeres and cinder-notch by means of the heat of the electric arc. We have heard that the surface-cracks or marks developed in rolling heavy plates have been closed by electric welding, as by a soldering-iron, and also that an electric burner has been employed at some German blast-furnaces; but the experiment was quite novel to us; and I think it constituted one of the first, if not the very first, successful application of this device, for the purpose named, in the United States. †

Jan 1, 1902

By Walter Lawson

THE first plans were made in 1930 for the mining by open-pit methods of the low-grade disseminated ore body now known as the Morenci open pit. It was not until 1937, however, that final plans were completed and the decision reached to go ahead with the actual development. Many advances were made in open-pit mining equipment during that period of seven years, therefore the ways and means of attack actually used were very different from those originally contemplated. Diesel-operated bulldozers, big trucks, full-revolving electric shovels and electric churn drills constitute the major equipment finally purchased for this modern stripping operation. Neither the bulldozers nor the big trucks were considered in the early operating plans, for at that time bulldozers had not, been used in mining operations and the trucks as yet were undesigned. The full-revolving shovel and the churn drills were not new developments in open-pit equipment, but both had undergone remarkable manufacturing transition, emerging far more efficient and far more dependable than their predecessors. Even the ordinary drilling steel had been fundamentally changed. It was now threaded so that the dulled cutting bits could be detached and replaced, thus eliminating the costly transportation of long bars to the drill shop for resharpening. The decision to use trucks in the preliminary stripping operations was based on the desirability of this type of transportation to economi-cally prepare the pit for rail haulage, coupled with the success that the contractors had had with them on other big excavation jobs. There are at present no plans for the use of trucks beyond the preliminary work, inasmuch as rail haulage will give lower costs after roadbeds and benches are once established.

Jan 1, 1938

By L. D. Fetterolf, G. T. Mahler, W. M. Peirce, R. K. Waring

Until recently, the only commercial method of producing magnesium has been fused salt electrolysis, despite a considerable amount of experimental work on the direct reduction of magnesium oxide. In this early work, a number of investigators demonstrated that magnesium oxide would react with any one of several reducing agents to produce magnesium vapor, but that the mixture of magnesium oxide and reducing agent must be heated to a high temperature even in a vacuum. In particular, it was demonstrated that silicon and aluminum are effective reducing agents and that when either of these is used the magnesium vapor can be condensed to massive metal. In spite of this knowledge, no successful commercial reduction process was developed, at least in this country, because of the operational difficulties imposed by the requirement of high temperature and vacuum and because of the high cost of the reducing agent. The outstanding experimental work done by Pidgeon, who carefully reviewed all of the known methods of making magnesium and then selected ferrosilicon reduction, overcame some of the operational difficulties. The process developed by Pidgeon comprises briquetting a mixture of calcined dolomite and reducing agent, preheating the briquets to about 600°C. in an externally heated alloy retort, reducing the MgO with silicon in an evacuated horizontal alloy retort heated externally to about II50 C., and condensing the magnesium vapor to a solid in a cold extension of the retort projecting beyond the front of the furnace. A major advantage of Pidgeon's process is that the retort is not cooled down between charges. Earlier investigators had used apparatus that necessitated cooling and reheating of the retort between charges. Early in January 1942, when the War Production Board was considering the Pidgeon process for quickly increasing the production of magnesium, The New Jersey Zinc Co. offered to have a research investigation of the process carried on, with the hope of assisting in its further development. This offer was accepted, and a two-retort pilot plant was built at Palmerton and put in operation on Jan. 29,1942. An intensive investigation of certain phases of the process was carried out in the ensuing four months. This investigation was completed in the last part of May 1942) and the pilot plant was then shut down. Subsequently, The New Jersey Zinc Co. was requested to have further development work done on the process, and a more extensive investigation was undertaken in August 1942 under contract with the War Production Board and under the supervision of the War Metallurgy Committee. This paper describes the ,phases of the investigation that are thought to be of sufficient general interest to merit publication.

Jan 1, 1944

By Edward Keller

In order to conduct intelligently the sampling of copper of various forms and grades, solid or in molten furnace-charges, a knowledge of this subject is essential. Yet figures and tests have been persistently withheld from publication, and the books at our command give us little or no information in this regard. This gap in our copper-literature has led to a series of experiments, the results of which are given below. Nearly all gold- and silver-bearing copper, destined for shipment, is cast into the form of bars or pigs. For the sampler, the question arises, Does copper, so cast, remain homogeneous ? If it does, sampling should present no difficulties; but, from experience, we know that this is not the case, and we are thus led to study the behavior of the precious metals arid impurities in copper when the latter changes from the molten to the solid state. For the purpose of the experiments here described, all available grades of copper were selected, and all of them mere subjected to the same conditions, an important requisite for proper comparison. The molten copper obtained directly from reverberatory- and blast-furnaces was cast in a cast-iron mould, the sides and bottom of which were 1 inch thick, and would, therefore, give the copper a fair length of time to chill. The inside dimensions of the mould, and, consequently, of the block of copper obtained, were: length, 10 inches; width, 9 inches; and depth, 5 inches. Fig. 1 illustrates the method employed to obtain samples from these blocks. A was cut away, and the face so produced BALTIMORE COPPER WORKS,

Jan 1, 1898

By S. H. Chauvenet

THE binding of the boshes and in walls of blast furnaces has always been an expensive piece of work. When the old stone stack was replaced by the iron shell, the brickwork was kept at a thickness of five feet or more. These five-foot walls were still too thick, and the practice now is to have as thin walls as possible and to have a free circulation of air about the brickwork of the furnace. The "basket," or lattice-work binding, accomplishes this object, but it is expensive, as to first cost, and, if any change in the diameter of a furnace has to be made, it necessitates an alteration of the binding or of the thickness of the walls.

Jan 1, 1882

By Magnus Troilius

The following is a very rapid method for determining copper in steel. I have found it to give results very closely agreeing with those obtained by galvanic precipitation of the copper. Five grams of steel are dissolved in a mixture of 100 C.C. of water and 10 C.C. of sulphuric acid. When all is dissolved, add 2 C.C.

Jan 1, 1883

By S. M. Brisbane

The life of refractory linings in rotary cement kilns can be shortened by uneven or inadequate support of the kiln and its shell and by variations in the conditions of operation. Alteration of these factors may, according to their nature, bring about mechanical deterioration of the lining or promote chemical attack. Chemical attack has been described elsewhere. The distortion of cement kilns has been discussed in a general manner by Rochow, who indicates the amount of distortion which may occur in an unlined shell, and by Rosenblad; who states that the deformations of the shell are greatest above the trunnions. The present article indicates the extent of the distortion of a kiln to an oval shape in certain selected positions and the deviation from a straight line of the kiln along its length between two supports. The cement kiln is a long, hollow, rotating cylinder consisting of steel plates which may be either welded or riveted together. This shell is supported on tires, frequently 60 ft apart, which roll on trunnions. The large mass of the kiln causes distortion of its cross-section; it becomes slightly oval, i.e., diameters lengthen as they become horizontal and shorten as they become vertical. There is also a tendency for the shell to bow between supporting tires; this bowing may be upwards or downwards depending on the position of the weight forces and the supports. The extent of the deviations from the ideal kiln shape was investigated.

Feb 1, 1956

By B. M. O Harra, George M. Fowler, R.E. Illidge

The Tri-State district comprises an area of about 2000 square miles in southwestern Missouri, southeastern Kansas, and north- eastern Oklahoma. The part that is in and contiguous to Missouri is still sometimes designated as the Joplin district (Fig. I). Early Operations Mining operations in what is now the Tri-State district date from about 1848 and have been continuous to the present. Apparently the first discoveries of ore were made about the same time near the present sites of Joplin, Oronogo, and Granby. Lead minerals were found at grass roots, probably in shattered rock in shallow excavations, then these minerals were followed in shear zones to deeper horizons. The mining of zinc followed. Before 1874, zinc ore was worthless and discarded as waste. According to published records, the total production of lead to that date was 49,000 tons of metal from 70,000 tons of concentrates. Production The a.ggregate ore production from the Tri-State district was recorded at intervals

Jan 1, 1943

By George M. Fowler, B. M. O Harra, R. E. Illidge

The Tri-State district comprises an area of about 2000 square miles in southwestern Missouri, southeastern Kansas, and north- eastern Oklahoma. The part that is in and contiguous to Missouri is still sometimes designated as the Joplin district (Fig. I). Early Operations Mining operations in what is now the Tri-State district date from about 1848 and have been continuous to the present. Apparently the first discoveries of ore were made about the same time near the present sites of Joplin, Oronogo, and Granby. Lead minerals were found at grass roots, probably in shattered rock in shallow excavations, then these minerals were followed in shear zones to deeper horizons. The mining of zinc followed. Before 1874, zinc ore was worthless and discarded as waste. According to published records, the total production of lead to that date was 49,000 tons of metal from 70,000 tons of concentrates. Production The a.ggregate ore production from the Tri-State district was recorded at intervals

Jan 1, 1943

J. M. HARTMAN, Philadelphia, Pa.: Mr. Fackenthal can remember some queer things that occurred at Durham, Pa., Aug. 3, 1876, while he was superintendent. The furnace was working stiff, i.e., blast-pressure 10 to 11 pounds, which was high pressure for those days. With this pressure there was some circulation through the stock. At 9 p.m., flushed cinder. After flushing, air was thrown off' for a moment to " bot up "; the keeper turned the lever and threw on air just as the scaffold dropped, which eased up the pressure to 4¼ pounds. The air-receiver is twice as large at Durham as at other places. The air from this receiver, added to the two seven-foot blowers, gave an extra large volume, which, rushing into the furnace, fired the finely-divided carbon, causing an explosion that threw part of the stock in the furnace out into the open air, threw up the bell-and-hopper with the tunnel-head plates, and gave off' a large volume of carbondust. The bell-and-hopper going up first, the stock followed, and, striking the bell-and-hopper, was deflected in a shower over the cast-house roof, breaking the slates. Sitting at the corner of the engine-house at the time, the stock pelted me, when I ran around the corner to get rid of it. Remembering there were two men at the furnace-top, I shut down the engines, and, running to the top, found them sitting in the hoist-house enjoying the fire-works. The explanation of this explosion is simple. There is in the blast-furnace a bed of fuel extending up, say, 16 to 18 feet above the tuyeres; in this bed of fuel some stray pieces of limestone are found, and a few pieces of unreduced ore; but, generally speaking, it is all fuel. On this bed of fuel is the zone of fusion. In this zone the descending stock is liquefied, except the fuel; the iron, melting, drops out of the ore, and the gangue unites with lime, forming cinder. The iron falls in the form of shot, and, with the cinder, trickles

Jan 1, 1899

By Cyril Stanley Smith

BETA brass (consisting of approximately equal atomic proportions of copper and zinc) exists as a random solid solution at high temperatures, but at low temperatures [ ] an ordered structure is stable, with the copper and zinc atoms occupying alternate sites on the body-centered-cubic lattice. On cooling, ordering commences at a temperature of 450° to 490°C., depending on the composition. The degree of ordering progressively increases at lower temperatures until it becomes virtually complete at about 100°C. The electrical resistivity of the alloy illustrates the changes clearly (Fig. I). This type of reaction has been a favored subject for study by physicists. An [ ] excellent summary of the theory is to be found in a paper by F. C. Nix and W. Shockley.1 All published data on electrical conductivity, specific heat and other properties agree in indicating that the ordering reaction in beta brass takes place so rapidly that it cannot be prevented or even retarded by quenching. With most ordered alloys, cold-working induces disorder and

Jan 1, 1942

Discussion of the paper of F. C. NEWTON, presented at the New York meeting, Feb-ruary, 1915, and printed in Bulletin No. 9S, February, 1915, pp. 473 to 477. H. 0. HOFMAN, Boston, Mass.-The results of these large-scale experiments, which were carried on at Perth Amboy, show that there are many differences between theoretical conceptions and their applications to work on a large scale. The author has given reasons why the results of bringing a desilverizing kettle to the high melting point of the zinc-silver alloy, Zn3Ag2, melting at 665° C., are not satisfactory. In all probability the alloy is dissolved in the lead; it may also be decomposed by the lead; the practical result is that this high temperature does not work. It remains now for the laboratory man to carry on systematic experiments

Jan 5, 1915

By Edward D. Peters

IT frequently occurs in the establishment of reduction works, in an entirely new and untried mining district, that the metallurgist in charge finds considerable difficulty in determining the process best adapted to the ores which he receives for treatment. At the first glance it would seem easy enough to decide what style of furnace is best adapted for beneficiating any one class of minerals. If the ore possessed a quartzose gangue and was comparatively free from base metals, while salt could be obtained at a reasonable price, one would naturally resort to a chloridizing roasting, and pan or barrel amalgamation for the extraction of its silver contents. If galena or carbonate of lead was the prevailing mineral, and charcoal could be obtained at moderate figures, the blast-furnace would beneficiate the ores most advantageously. But if, as is usually the case in Colorado, the ores consisted of an intimate mixture of galena, zinc-blende, copper-pyrites, and noble silver minerals, associated with an overwhelming mass of siliceous heavy spar, or limestone gangue, the common reverberatory furnace can be used to the greatest advantage; and, although the product is only a copper matte, I do not hesitate to affirm that it can be treated, and the silver, gold, and copper produced at nearly the same price for which silver and lead can be separated. In Germany, blast-furnaces are frequently used for this same purpose, both for argentiferous and non-argentiferous copper ores ; but any one who will take the trouble to examine the statistics of smelting at Fahlun, the Oberharz, and other Continental works of this description, will see that the expenses are far too great, and the production much too small to think of employing this method in our mining districts, where only the softest and most miserable kind of charcoal is obtainable. I propose in this paper to give an accurate account of the expenses incurred at the Mount Lincoln Smelting Works in treating the same kind of ore, and producing the same end-product in both blast and reverberatory furnaces. I have taken for comparison a favorable campaign of the blast-furnace, and a good average month's running of the reverberatory. In the blast-furnace estimate I have included the calcining and concentration of the matte produced during that campaign, as I always, when possible, concentrated the regulus made

Jan 1, 1874

By Roy A. Hardy

The Getchell mine is a comparatively recent discovery in the old Potosi mining district, Humboldt County, Nevada, a district organized in the seventies and eighties, in which some prospecting was done in several metamorphic zones along a monzonite-sedimentary contact. The district had no production in the early days and no further work was done until the same metamorphic zones were prospected for tungsten (scheelite) in 1917 and 1918, when a few small lots were shipped. It again lay dormant until 1934, when prospectors investigated a large siliceous escarpment at one end of the old district where outcroppings were a prominent feature of the topography. Undoubtedly, during the early prospecting of the district, the outcroppings had been investigated for mineral, probably by panning, with negligible results because the gold later found is invisible in the concentrate and is refractory. A fire assay revealed the presence of sufficient gold to warrant development work. The outcroppings were easily prospected by short tunnels having their portals in the siliceous material on the hanging-wall side, with a maximum distance to crosscut to the footwall of 135 ft., or a distance at right angle to dip of 60 to 90 ft. Development work, reaching a depth of over 600 ft. on the dip of the vein, was done by means of various crosscut tunnels, winzes and laterals. A churn-drill hole was also sunk, which intersected. the vein at a depth of 1100 ft. on the dip. Sufficient development work of this character was completed by 1937 to justify the erection of a reduction plant to roast the sulphide ore and cyanide the calcine, and to treat the oxidized ore by straight cyanidation, to make a doré bullion for shipment to the mint. The erection of the plant was started that year and finished early in 1938; with a combined capacity of about 800 tons per day. It has operated continuously since erection and recently was enlarged to handle 1000 tons per day. The vein dips with the slope of the mountain, and by stripping the hanging wall the ore may be mined by power shovel for several hundred feet below the outcrop. Thereafter underground methods will be necessary.

Jan 1, 1941

By Roy A. Hardy

The Getchell mine is a comparatively recent discovery in the old Potosi mining district, Humboldt County, Nevada, a district organized in the seventies and eighties, in which some prospecting was done in several metamorphic zones along a monzonite-sedimentary contact. The district had no production in the early days and no further work was done until the same metamorphic zones were prospected for tungsten (scheelite) in 1917 and 1918, when a few small lots were shipped. It again lay dormant until 1934, when prospectors investigated a large siliceous escarpment at one end of the old district where outcroppings were a prominent feature of the topography. Undoubtedly, during the early prospecting of the district, the outcroppings had been investigated for mineral, probably by panning, with negligible results because the gold later found is invisible in the concentrate and is refractory. A fire assay revealed the presence of sufficient gold to warrant development work. The outcroppings were easily prospected by short tunnels having their portals in the siliceous material on the hanging-wall side, with a maximum distance to crosscut to the footwall of 135 ft., or a distance at right angle to dip of 60 to 90 ft. Development work, reaching a depth of over 600 ft. on the dip of the vein, was done by means of various crosscut tunnels, winzes and laterals. A churn-drill hole was also sunk, which intersected. the vein at a depth of 1100 ft. on the dip. Sufficient development work of this character was completed by 1937 to justify the erection of a reduction plant to roast the sulphide ore and cyanide the calcine, and to treat the oxidized ore by straight cyanidation, to make a doré bullion for shipment to the mint. The erection of the plant was started that year and finished early in 1938; with a combined capacity of about 800 tons per day. It has operated continuously since erection and recently was enlarged to handle 1000 tons per day. The vein dips with the slope of the mountain, and by stripping the hanging wall the ore may be mined by power shovel for several hundred feet below the outcrop. Thereafter underground methods will be necessary.

Jan 1, 1941