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There's a right way and a wrong way to store diesel electric systems and similar equipment for generating on-site power, according to James Frankow, service manager for Allis-Chalmers Corp's Engine Division. In any event, the less storage the better. Many generating sets are stored before installation, especially when new construction is underway. Improper storage, or mothballing, can create initial reliability problems. Therefore; arrange for inside storage with no drastic extremes in temperature or humidity. If engines and alternators are stored in areas other than inside a dirt-free and temperature-controlled building, the unit or engine should be completely covered and protected against the environment. Before covering it with a canvas or with plastic, the unit should first be sealed at the following critical engine openings:

Jan 3, 1978

ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Graduate mining engineer, with 10 years' experience, having an office in New York, would like to represent a mining company as selling and purchasing agent, and general supervision if desired. Machinery agency considered. No. 259. Member, technical graduate, with several years' experience as engineer for a pyrites company, and as geologist and engineer for copper, nickel, and silver companies, desires a position as engineer or superintendent of mines. No. 260. Member, technical graduate, aged 29, with experience as draftsman, surveyor, and superintendent of iron and gold mines, and as construction engineer, is open for a position as mine superintendent, or in mine examination or construction. No. 261.

Jan 11, 1915

By H. E. Montgomery

H. L. Burghoff.*—I have a question, Dr. Smith. A number of the alloys you mentioned contain lead, which, of course, is present as discrcte particles. At what level of concentration does lead begin to play an important part in determining these elevated-temperature characteristics ? A. J. Smith.—That is a difficult question to answer because of the complicating features of the alloys that arc lead free. I do not know of any work done on the subject. But for comparison, 85-5-5-5 has about the same characteristics at, say 450°F. as 88-10-2, which is lead free or contains at most 0.30 per cent. Both 85-5-5-5 and 88-10-2 precipitate delta. The specification limit of usage is 406°F., temperature of saturated steam at

Jan 1, 1945

By Chas. Kohl

ABOUT 1929 an engineer was engaged to organize a Safety Department, lay out an educational program, and achieve a reduction in accident frequency. Due to the large number of employees, about 12,000, and the distances between the various properties, it was a big undertaking. Most of the workmen are from the Sierra and for generations have been agricultural people, with little conception of modern tools and machinery, and to a large degree are illiterate. However, gratifying results have been obtained, as evidenced by the accident frequency curve during the sixteen-year period. Safety offices have been established in each of the six major properties, staffed by men who devote their entire efforts to inspections of working conditions and equipment, instructions as to safe methods, and investigations of accidents. The Corporation is a member of the Inter-American Safety Council, receiving their publications and literature, which serve to keep us up to date and informed on modern methods. Dissemination of this material is accomplished chiefly through word-of-mouth and bulletin boards. When it is found that the accident rate is increasing in a certain occupation, as for instance underground haulage or mine hoisting, the operators so engaged are assembled and given renewed instructions on the safety code pertaining to their work. Inter-camp competitions in accident avoidance are being conducted, with annual awards for that unit having the lowest severity rate for the year.

Jan 1, 1945

By G. L. Wilhelm

Prior to the construction of a 450 tpd concentrator at the Mayflower mine, owned by the New Park Mining Co. and operated by the Hecla Mining Co., the common mining methods were cut and fill, with waste or gob filling and square set timbering with waste fill. Stoping operations were beset with the usual problems related to waste filling methods- storage and handling of fill material from development, costly waste excavations necessary to obtain a portion of the needed waste rock, slow mining cycles due to filling and inefficient ground support. After Hecla Mining Co.'s successful utilization of sandfill in its mines in the Coeur d'Alene district, utilization of hydraulic fill in stoping operations at the Mayflower was a logical development of the modernization plan then in progress. The mine, located in the southeasterly part of the Park City mining district, Utah, is a medium size producer of lead and zinc ores, with gold, silver and copper as secondary minerals. The mine has been producing commercial ore since 1939 from a dual vein system which outcrops at an elevation of 7200 ft in the Wasatch Range. Access to the present mining areas is gained by a 7200-ft haulage tunnel and by an interior, three-compartment main shaft. The present mining horizons are about 2400 ft deep. The average horizontal cut and fill stopes, ranging from 3-15 ft wide and up to 120 ft long, can be classed as small.

Jan 5, 1968

By HERRBERT HOOVER

I AM glad to join with my fellow-members in this celebration of the fiftieth anniversary of the founding of the American Society of Mechanical Engineers. It would be a difficult task to measure the blessings brought by this association through the stimulation to invention, the improvement of methods, the adequate training of engineers and the advancement of knowledge in a large sense. During its span of life it has contributed a great part in the development of an art into a mighty profession upon whose capacity and fidelity rest so much of human progress. "I feel especially honored that the association should, through the beneficence of Mr. Lauer, have established a new distinction among engineers, and should have designated me as its first recipient. The purpose of this medal is to mark the public service of men who have gone outside their strictly professional work to interest themselves in civic and humanitarian affairs. And the engineers have something to contribute to public service. . "With the development of our great national tools -our engines, our railways, our automobiles, our airplanes, our steamships, our electric power and a score of other great implements, together with the supplies of material upon which they depend-the engineer has added vastly to the problems of government, for government must see that the control of these tools and these materials is not misused to limit liberty and freedom, that they advance and do not retard equality of opportunity among all our citizens.

Jan 1, 1930

"The largest variety of asphalt and related bitumen deposits in this country is found in Utah. Utah is one of the few places in the world where the hydrocarbon minerals, gilsonite or uintaite, wurtzilite (trade name elaterite) and ozokerite are produced. These bitumens occur in an area embracing nearly 10,000 square miles in eastern Utah near the Colorado line. This area is largely in the western part of the Uintah basin. The bitumens are in the Tertiary horizon in the various divisions of the Eocene series.Gilsonite is an asphaltite derived from petroleum, wurtzilite is an asphaltic pyrobitu¬men derived from petroleum, and ozokerite is a native mineral wax resulting from the met-amorphosis of paraffinaceous petroleum.Gilsonite is produced by the Gilson Asphaltum Company, a subsidiary of the Bar¬ber Asphalt Company, at Watson, Utah. A narrow guage railroad, seventy miles in length and with a 7 1/2 percent grade over the Book Cliffs on Baxter Pass, was constructed by the company from the Denver & Rio Grande Western railroad main line in order to open up the gilsonite deposits. The veins range from narrow upward to 18 feet in width. The Rainbow vein at the present wokings is eight feet wide, vertical, and has sandstone walls. This vein has been opened up for a distance of about three miles and in some places four hundred feet deep. Forty men usually are employed with a production of eighty tons per day."

Jan 1, 1925

By W. P. Lass

Discussion of the paper of W. P. LASS, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 103, July, 1915, pp. 1443 to 1447. ROBERT M. KEENEY, Somersville, Conn. (communication to the Secretary *).-There is not only a possibility of improvement in present methods of treatment of the byproducts of refining in the cyanide plant by the use of the electric furnace, but also in melting and refining of gold precipitate. This interesting paper by Mr. Lass shows an electric furnace in successful operation in a large plant for the treatment of by-products. Electric melting of cyanide precipitate is a cheaper form of treatment in many cases than any of the combustion methods now used because of the high cost of oil, coke or coal in many camps, while on the other hand electric power may be had cheaply, especially in a place where there is possibility of development of high-head hydro-electric plants for power purposes. Also, if the oil-fired tilting furnace is used for direct melting of the precipitate, as is the case at many small mills, a great saving in cost is made by the use of the electric furnace because of the high crucible cost in melting with the tilting furnace. A study of this paper indicates the cost of the operation approximately. Consider all the fluxes to be turned in as byproducts and coke at $18 per ton.

Jan 12, 1915

By Behram H. Wadia, Robert S. Lehto

A new metallurgical treatment for capturing as much of the values as possible from zinc refinery feed has been devised by personnel in Cerro de Pasco's Peruvian operation at La Oroya. Results from a pilot test illustrate that 50 metric tons of throughput can be maintained whereby substantially all the silver and copper report in the sponge iron while zinc and lead with indium and cadmium volatilize in the fume. This new technique named the Zileret (zinc leach residue treatment) process complements the electrolytic system used in the refinery so that all values in a zinc concentrate are economically recovered. In the system, dried zinc leach residue is pelletized with soluble zinc sulfate which already exists in the leach residue and a finely divided reducing agent such as anthracite coal. Upon heat addition, the loose anthracite in the charge maintains a reducing atmosphere while the free space above the charge has an oxidizing nature. When the charge reaches the reaction zone at about 1100°C, metals such as zinc, lead, cadmium and indium volatilize from the pellets, are oxidized in the upper kiln atmosphere, and are then carried in suspension as an oxide fume to the cooler and baghouse. The copper and silver content in their reduced forms, along with the iron, discharge from the kiln as a calcined product which is then cooled to below 130°C before being exposed to the air.

Jan 9, 1969

By Eric Kula, Åke Josefsson

L. J. Dijkstra and R. Sladek, (Ontario Research Foundation, Toronto, and Institute for the Study of Metals, Chicago, respectively)—This interesting paper confirms some results obtained some years ago in collaboration with Fast: namely the broadening of the nitrogen peak by the presence of small amounts of manganese. Later on a more extensive study of this effect was made at the Institute for the Study of Metals at Chicago. As the work has not yet been submitted for publication we wish to mention here briefly some of the results. The effect of about 0.5 atomic pct manganese, chromium, molybdenum, or vanadium on the nitrogen-peak in iron was examined. The broadening found previously in the case of manganese was even found to be more pronounced for chromium. In the case of molybdenum and vanadium a double peak was observed which seemed to justify the idea that in all cases mainly two relaxation times were involved: namely, the normal relaxation time as found in pure iron and a second relaxation time related to the existence of abnormal interstitial lattice sites introduced by the foreign metallic element. The analysis showed that for the normal nitrogen-peak as a reference at 22°C the abnormal peak was found at about 32°, 47°, 75°, and 87°C in the case of manganese, chromium, molybdenum, and vanadium, respestively. In the manganese alloy the free energy difference for a nitrogen-atom at an abnormal and a normal lattice site was estimated at 2800 cal per mol. This means that for temperatures above 100°C the solid solubility and overall diffusion rate of nitrogen is not much affected by additions of 0.5 pct Mn. We believe that the difference in rate of precipitation of nitrogen in pure iron and the manganese alloy is mainly a question of the number of potential nuclei available in the different steels. In studying the effect of these alloying elements on precipitation of nitrogen, a distinction must be made between the para reaction and ortho reaction, using terminology introduced by Hultgren.7 The ortho reaction in which the alloying metallic element participates in the diffusion under formation of nitrides occurs at high temperatures such as 600°C. The para reaction in which the alloying metallic element does not diffuse and in which the nitride inherits its alloy content from the matrix occurs at lower temperatures. To prevent the ortho reaction the alloys have to be quenched rapidly from the phase. It is not surprising that the authors find that the height of the peak indicates a lower nitrogen content than chemical analysis. In the first place the peak is not a single relaxation peak and secondly, the steels were not quenched from the phase after the nitrogen was introduced at 580 °C.

Jan 1, 1953

By H. F. Yancey, M. R. Geer, C. L. Allyn, R. H. Eckhouse

Four coals were treated in the Humphreys spiral concentrator, and the products were examined by float-and-sink and screen-sizing tests to determine fundamental performance characteristics. The efficiency of the separation between coal and impurity was shown to be influenced greatly by particle size. FOUR coals exhibiting different washability characteristics were washed in the Humphreys spiral concentrator and the products examined by float-and-sink and screen-sizing tests to determine the mechanics of the separation between coal and impurity. With one coal, each 1/2-in. increment of the full width of the stream in the spiral was examined separately to determine where each size and specific-gravity fraction of the feed was stratified. The basic performance characteristics of the spiral were found to be the same for all of these coals. The coarsest fraction of heavy impurity stratified so far out in the stream that it could not be removed through the refuse ports and thus either entered a middling product or contaminated the washed coal in the case of a two-product separation. Impurity particles finer than about 100-mesh also were carried out in the main body of the stream and therefore were not removed in the refuse product. Little loss of clean coal in the refuse occurred in sizes coarser than 28-mesh or finer than 100-mesh, but considerable coal of intermediate size stratified in the stream that was drawn off through the refuse ports. Because of this modifying influence of particle size, the spiral is unable to make an efficient two-product separation between coal and impurity without some retreatment. Recirculation of a middling product through the same spiral as a means of obtaining more efficient operation was not attempted in this investigation. The size and specific-gravity composition of the middling product are, however, such as to render it amenable to simple hydraulic classification for recovery of coal. Retreatment of a middling product would improve the efficiency of the spiral, but even when making a substantial amount of middling, considerable clean coal enters the refuse product. Consequently, retreatment of a combined refuse-middling product would appear to offer greater promise for providing maximum efficiency. Because of the sizing characteristics of the spiral, a classified feed can be treated with higher efficiency than is possible on a natural raw coal. For this reason, semiclassified feeds, such as silt-bank or classifier-underflow materials, can doubtless be treated with higher efficiencies than those shown for raw coals in this report. Performance is, of course, only one of many factors that enter into the choice of cleaning equipment. The fact that the one company now using the spiral for cleaning coal has built a second spiral plant is ample evidence that the inherently low efficiency of this unit may be overshadowed by the low operating costs afforded by its extreme simplicity. Introduction A number of factors enter into the selection of coal-cleaning equipment, and most of them bear directly on the final cost of prepared coal. One of these factors is performance of the cleaning unit in terms of the efficiency of the separation it effects between clean coal and refuse. The importance of performance in the selection of a coal-cleaning unit varies with the difficulty of the cleaning problem. Obviously, if the character of the coal is such that only certain types of cleaning units are capable of yielding a clean product meeting market requirements, performance is of prime importance. If, on the other hand, the cleaning problem is so simple that any type of cleaner will provide coal of suitable quality, performance is important only insofar as it affects costs by determining the amount of salable coal lost in the washery refuse. With the objective of providing the coal industry with information that is helpful in the selection of

Jan 1, 1951

By R. H. Eckhouse, M. R. Geer, H. F. Yancey, C. L. Allyn

Four coals were treated in the Humphreys spiral concentrator, and the products were examined by float-and-sink and screen-sizing tests to determine fundamental performance characteristics. The efficiency of the separation between coal and impurity was shown to be influenced greatly by particle size. FOUR coals exhibiting different washability characteristics were washed in the Humphreys spiral concentrator and the products examined by float-and-sink and screen-sizing tests to determine the mechanics of the separation between coal and impurity. With one coal, each 1/2-in. increment of the full width of the stream in the spiral was examined separately to determine where each size and specific-gravity fraction of the feed was stratified. The basic performance characteristics of the spiral were found to be the same for all of these coals. The coarsest fraction of heavy impurity stratified so far out in the stream that it could not be removed through the refuse ports and thus either entered a middling product or contaminated the washed coal in the case of a two-product separation. Impurity particles finer than about 100-mesh also were carried out in the main body of the stream and therefore were not removed in the refuse product. Little loss of clean coal in the refuse occurred in sizes coarser than 28-mesh or finer than 100-mesh, but considerable coal of intermediate size stratified in the stream that was drawn off through the refuse ports. Because of this modifying influence of particle size, the spiral is unable to make an efficient two-product separation between coal and impurity without some retreatment. Recirculation of a middling product through the same spiral as a means of obtaining more efficient operation was not attempted in this investigation. The size and specific-gravity composition of the middling product are, however, such as to render it amenable to simple hydraulic classification for recovery of coal. Retreatment of a middling product would improve the efficiency of the spiral, but even when making a substantial amount of middling, considerable clean coal enters the refuse product. Consequently, retreatment of a combined refuse-middling product would appear to offer greater promise for providing maximum efficiency. Because of the sizing characteristics of the spiral, a classified feed can be treated with higher efficiency than is possible on a natural raw coal. For this reason, semiclassified feeds, such as silt-bank or classifier-underflow materials, can doubtless be treated with higher efficiencies than those shown for raw coals in this report. Performance is, of course, only one of many factors that enter into the choice of cleaning equipment. The fact that the one company now using the spiral for cleaning coal has built a second spiral plant is ample evidence that the inherently low efficiency of this unit may be overshadowed by the low operating costs afforded by its extreme simplicity. Introduction A number of factors enter into the selection of coal-cleaning equipment, and most of them bear directly on the final cost of prepared coal. One of these factors is performance of the cleaning unit in terms of the efficiency of the separation it effects between clean coal and refuse. The importance of performance in the selection of a coal-cleaning unit varies with the difficulty of the cleaning problem. Obviously, if the character of the coal is such that only certain types of cleaning units are capable of yielding a clean product meeting market requirements, performance is of prime importance. If, on the other hand, the cleaning problem is so simple that any type of cleaner will provide coal of suitable quality, performance is important only insofar as it affects costs by determining the amount of salable coal lost in the washery refuse. With the objective of providing the coal industry with information that is helpful in the selection of

Jan 1, 1951

By Clyde Evarts Weed

SOME one once affirmed his great belief in luck, adding that he had found that the harder he worked the more luck he had. Clyde Weed is a firm believer in this method of courting the fugitive lady. He is at work early and late, often leaving his staff at Anaconda's offices at 25 Broadway breathless trying to keep up with the ideas teeming from a fertile brain and the actions those ideas entail. Miles ahead of his assistants much of the time, he still manages to be an agreeable fellow to work with, no small accomplishment as many can testify. Mr. Weed arrived in the world at Moorestown, Mich., on Aug. 8, 1890. Sixteen years later he entered Michigan Agricultural College, a lowly freshman. The following year, with the experience and wisdom expected of a sophomore, he transferred his studies from the reaping of a harvest on the surface of the earth to delving into the deeper, unpredictable bowels of the earth, his studies now shifted to the Michigan College of Mines. Last June his alma mater conferred upon him the degree of Doctor of Engineering.

Jan 1, 1947

By AIME AIME

This volume, in the preparation of which all former annual or collective indexes have been not only compiled but revised, is published for the special benefit of all who do not possess complete sets of the Transactions. And it is published at this particular time, as part of a plan by which it is hoped that the Library of the Institute, which, through liberal donations, has become unexpectedly comprehensive and valuable, may be made useful throughout the world. Thus, any person possessing this Index can ascertain at once what has been published in the Transactions on a given question, and can learn, by writing to the Secretary, what is its nature, whether it is still to be had in pamphlet form, where it can be consulted in a public library, at what cost it can be copied by hand, etc., etc. In short, to those who own complete sets of the Transactions, this Index will be a great convenience; but to those who do not, it will be a professional necessity. The edition now in press is limited, and orders received will be supplied according to date.

Jul 1, 1907

By S. P. Kinney, A. J. Boynton

This paper states that progress in blast-furnace engineering during the past five years is unimportant except for the advent of the electric precipitator for gas cleaning. It describes improvements in certain furnace details and in materials of construction. The paper is largely given over to a discussion of difficulties in operation due to disproportion between the diameter of the present-day furnace at the bosh and at the stock line. It is proposed to remedy this disproportion, and to restore relations in the diameter of stock line and bosh as they formerly existed, by a new method of filling. This method requires a double bell arranged to discharge towards the periphery or towards the center of the furnace. Coke is classified into two sizes, the small size going to the middle of the furnace, and the larger to the periphery along with the ore. By this means the resistance of the center of the furnace is increased, and the stock line diameter may be greatly increased. The writer believes that these modifications will result in a somewhat improved fuel economy and regularity of operation and also in a very greatly reduced production of flue dust.

Jan 1, 1935

By S. P. Kinney, A. J. Boynton

This paper states that progress in blast-furnace engineering during the past five years is unimportant except for the advent of the electric precipitator for gas cleaning. It describes improvements in certain furnace details and in materials of construction. The paper is largely given over to a discussion of difficulties in operation due to disproportion between the diameter of the present-day furnace at the bosh and at the stock line. It is proposed to remedy this disproportion, and to restore relations in the diameter of stock line and bosh as they formerly existed, by a new method of filling. This method requires a double bell arranged to discharge towards the periphery or towards the center of the furnace. Coke is classified into two sizes, the small size going to the middle of the furnace, and the larger to the periphery along with the ore. By this means the resistance of the center of the furnace is increased, and the stock line diameter may be greatly increased. The writer believes that these modifications will result in a somewhat improved fuel economy and regularity of operation and also in a very greatly reduced production of flue dust.

Jan 1, 1935

Two Canadian mining companies, Noranda Mines, Ltd., and Wright-Hargreaves Mines, Ltd., have agreed to buy $500,000 worth of shares each in Anglo-American Exploration Ltd., controllers of thousands of acres of possible oil-rich land in southern Saskatchewan and Manitoba. Samuel Clarence Nickle, Sr., reported as possible president of the newly formed exploration company, said that $20 million in assets have been accumulated by the firm, mainly in the Williston basin in parts of the Dakotas and Montana, aid extending into Southern Manitoba and most of Saskatchewan. The M. A. Hanna Co. reported a record profit for the seventh consecutive year with total 1951 profit reaching $14,081. The company handled a record 16.8 million tons of iron ore in 1951, compared with 14.9 million tons in 1950. The company is also preparing to open four iron ore mines in the Lake Superior district which are expected to produce more than 5 million tons annually by 1954. The company built two new iron ore concentrating plants at Mesabi range mines in 1951,a with a third plant going into, operations soon.

Jan 1, 1952

MINING AND METALLURGICAL SOCIETY OF AMERICA San Francisco Section The San Francisco Section of the Mining and Metallurgical Society of America held a joint meeting with the local section of the American Institute of Mining Engineers at the Engineers' Club, San Francisco, on Tuesday, Apr. 16, 1918. The meeting was preceded by a dinner. Letters from the parent body in NewYork asking for the consideration of the proposed bill before Congress, and an expression of opinion relative to the appointment of a Federal Administrator of Mines justified the joint meeting of the local sections of the two mining societies, in that a more representative opinion of the engineers of California could he obtained. The meeting was called to order at 7:15 P.M. by Mr. Frank H. Probert acting as Chairman. About thirty engineers were present. Mr. Probert read a letter of March 14, from Secretary Huntoon, asking that the meeting be called. He read excerpts from Bulletin 117 of February 28, 1918, of the Mining and Metallurgical Society containing a copy of the proposed bill, so that all present might be advised of its essential contents. He briefly commented on the urgent need of such legislation and invited discussion of the subject. After long and thorough discussion on the part of the members present, Professor Lawson made the following motion: I move that a resolution expressing the sense of the joint meeting of the local sections of the American Institute of Mining Engineers and Mining and Metallurgical Society of America be forwarded to the secretaries of the two societies to the effect that we heartily approve of the purpose and intention of the bill designed to promote and stimulate the production of minerals necessary for the successful prosecution of the war; and that we suggest prices should be fixed for the period of the war and two years thereafter, and that these prices, guaranteed by the Government, should apply at the nearest shipping point to place of production of the minerals. This motion was carried. The meeting then adjourned, and a telegram was sent by Mr. Probert, the Chairman, to Mr. Huntoon, notifying him of the motion that had been carried at the meeting.

Jan 7, 1918

By Walter Miller

The broad picture of petroleum refining engineering during 1934 continued to show a tendency in the direction of highly specialized processing improvements, particularly in manufacture of lubricating oil. The slowing up of the trend toward higher octane products in non-premium gasoline noticed in 1933 was definitely established as a fact by 1934 development, with just a slight indication of recession. No outstanding engineering achievements can be credited to 1934 in refinery cracking, unless the completion and successful operation of the 30,000-bbl. crude capacity combination cracking and skimming unit at Texas City, Texas, and a 20,000-bbl. similar unit in the East can be listed as such. Development and improvement was largely a continuation of previous lines of endeavor. Such trend as there is shows a continnation in the direction of very large integrated skimming and cracking units. A lessening of the cost of ethyl lead, coupled with the reaching of the octane number "ceiling," kept the subject of "reforming" low-octane gasoline into high-octane products pretty well in the background. Considerable interest, however, was shown during the year in cracking and polymerizing of refinery gases into high-octane motor fuel. The commercial development and application of this activity was greater in 1934 than during any previous year. Fair yields of gasoline of satisfactory stability and high antiknock value were reported, ranging from 2 to 8 gal. per 1000 cu. ft. of fixed refinery gas, yields varying with both the nature of refinery gas treated and processing methods. Assuming economic feasibility, regarding which there is still difference of opinion, gas polymerization offers the industry a possible outlet for its gases more in keeping with its basic chemical composition and value. The increased interest of railroads and heavy-duty truck and tractor manufacturers served to focus more attention on diesel fuels. The publicity given the Union Pacific diesel train, the Burlington "Zephyr" and others operated on special diesel fuels served to revive the intimations and fears of several years ago as to the ultimate replacement of the gasoline motor by diesel engines in even the passenger car field. How-

Jan 1, 1935

By R. A. Wagstaff

The method of charging a reverberatory furnace has changed many times since smelting was introduced in this country from the old smelters of Swansea, England. The cause of the latest change at the Garfield plant has been the excessive fineness of the charge due to fine grinding in the concentration of the crude copper ores. The many desirable features of deep-bath smelting as now used at Garfield have been proved. The old method of dropping the charge through holes in the arch (known as center-feed method) causes excessive dusting which makes heavy slag and flue-dust losses, also rapid deterioration of the silica brickwork of the furnace through fusion with the iron oxides from the dust. The purpose of this paper is to describe a gun feeder that was designed to overcome the disadvantages of the older methods of center feeding and still maintain the good features of deep-bath smelting with the hot finer charge. A gun feeder was designed to introduce the finely divided hot calcines under the moving gas stream of the combustion zone and still have them spread in a uniform blanket over the highly heated matte bath. The temperature of the furnace was so great that it was impossible to maintain a stationary feeder, so a movable feeder was designed that could be introduced into the highly heated zone and be withdrawn after the charge had been dropped. It was necessary to protect the nozzle of the gun with a water-cooled coil. Many different types of protected nozzles were tried, such as air jackets, water jackets and heat-resisting steel alloys, but none proved satisfactory. The angle of inclination of the feeder was found to be an important factor in spreading the charge evenly over the surface of the bath. An angle of 34" to 37" was found to be the most advantageous. To allow a continuous flow of ore from the charge car to the point of discharge inside the furnace, the feeder was made with telescopic connections. The pipe leading from the car is stationary and forms the inside part of the telescope. The outside section of the telescope is movable, and is

Jan 1, 1934