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The Institute is custodian of funds for support of numerous gold medals and prizes and has representatives on boards awarding still others. Details regarding the Institute Awards are given below. The Institute is represented on the boards of the John Fritz Medal, the Hoover Medal and the Washington Award, in connection with the three national societies of Civil, Mechanical and Electrical engineering; and, also, in the case of the Washington Award, with the Western Society of Engineers.

Jan 1, 1929

By Joseph H. M. Beaty, Gust Bitsianes

Successful blast-furnace operation depends upon securing an optimum balance between a number of important variables. This balance will vary somewhat from furnace to furnace in the same plant and with raw materials available in different plants. It is difficult to isolate the effect of any one variable unless it has a rather pronounced effect upon the efficiency of operation. The physical properties of iron ore and coke are known to affect the process, yet it is difficult to set up any definite yardstick by which these differences can be appraised. In recent years, whenever practicable, operators have taken steps to obtain better control over the absolute size and uniformity of size of the ore and coke. The size and physical character of the stone, however, have received comparatively little attention, emphasis being placed upon chemical composition, fluxing efficiency, and action as a desulphurizing agent. Since the stone occupies only about 10 per cent of the volume of the stock column, its influence upon permeability is less than that of the ore and the coke. The large pieces now used have a tendency to roll to the center and thus increase the permeability of this part of the stock column. Smaller pieces would be more effective in promoting the permeability of denser portions of the stock. The size and physical properties of blastfurnace stone are important also for reasons best understood by considering the results obtained by the crushing and the sizing of iron ore. Crushing ore to about 2 in. at Provo, Utah, and to about I in. in Alabama produced material somewhat less permeable to gases, even though sized. In spite of some sacrifice in permeability, the efficiency of the process was improved by crushing and sizing the ore, as indicated by a substantial saving in fuel and increased output. This saving in fuel is due in large measure to more thorough reduction of ore in the upper part of the furnace and to a corresponding decrease in the amount of carbon consumed prematurely above the tuyeres by the reaction CO2 + C = 2CO - 70,080 B.t.u. [I] The physical properties of stone, its size and rate of calcination are important because they influence the rate at which CO2 is released and the completeness of calcination before reaching a level in the furnace where the temperature does not exceed 1050°C. (1920°F.). Briefly, carbon dioxide from the limestone or from the reduction of ore may cause premature corn bustion of carbon above the tuyeres. Assuming that 1000 Ib. of limestone is used per ton of pig iron, about 435 Ib. of CO2 will be liberated during calcination of a good grade of stone. If all this CO2 from the stone were to oxidize carbon prematurely, about 120 lb, would be consumed above the tuyeres in a heat-absorbing reaction. The amount of carbon thus consumed when a

Jan 1, 1943

Through the courtesy of Mr. J. H. Batcheller, we are able to give the following extracts from a letter written by Mr. Caetani: It has been a nice idea of yours to collect for me all those scraps of news I received a few days ago and to send me such a long interesting letter. In four years war I have had practically no news. Burch wrote several times but several of his letters were lost and so mine. I believe I even wrote to you. Much has changed since our last days in Telluride; here and there many have disappeared. Of myself I will tell you in a few words: for a year I was in Cadore(?), where I had the good luck to do to the others what they wished to do to me, and had good luck on my side. Then I went to Macedonia for 5 months, did little fighting but lost my faithful fellow officer and companion.

Jan 6, 1919

By O. George Specht, Carl A. Zapffe

IN recent print, some remarkably contradictory statements have appeared regarding the importance to be attached to sponge iron,1-6 a metallurgical commodity whose history goes back at least to the time of Diodorus Siculus in the fourth century B.C. This disagreement, however, expresses the lack of a satisfactory method for producing sponge iron rather than defection in the commodity. The blast furnace is admitted to have certain inherent disadvantages, such as a general unsuitability for magnetite and the heating and blowing of vast quantities of undesirable nitrogen, so that a workable sponge-iron process remains attractive. In this respect, low-temperature gaseous reduction shows especial promise; but confusion persists regarding the factors involved. The present paper, therefore, has three principal divisions: (I) an exhaustive examination of all previous work on low-temperature gaseous reduction, (2) experimentation on the reduction of a magnetite with hydrogen, and (3) development of certain thermodynamic relationships in reduction, with a summarized depiction of the factors in the general process. PREVIOUS INVESTIGATIONS Gaseous media used in the reduction processes under discussion can be classified in three types: (I) H2, (2) CO, and (3) other gases. In the second, the CO is often admixed with H2. The third principally comprises hydrogeniferous gases, such as natural gas and producer gas, and in addition includes chlorine. Because hydrogen therefore features in all three, a study of hydrogen reduction based on investigations using pure hydrogen alone may be incomplete. The present paper reviews the three groups of investigations in the listed order, paying particular attention to hydrogen reduction. For the benefit of future workers, an exhaustive bibliography has been prepared and similarly classified. GROUP I: REDUCTION WITH HYDROGEN Equilibria Although the present problem is specifically one of kinetics, a first consideration is the equilibrium of the system, since the reactions to be studied comprise that equilibrium, and their direction and end points are defined by it. The historic development of these researches is interesting and informative.

Jan 1, 1946

By H. W. Graham

[ ] Even though we have a small audience, I am sure there are some here who are interested in sponge iron. It is a large subject, with a lot of economic interest, and one that will continue to grow in importance as the years go by and as the conditions that urge action in that direction increase. The authors have chosen to deal in this paper with one particular narrow phase of a long program of work by the Bureau of Mines. Before asking for any general discussion, I would myself like to ask Mr. Buehl if he would tell us just a little bit about the mechanism of discharge and the form in which the material was discharged; that is, when dolomite is added, what happens to the dolomite? R. C. Buehl (author's reply)-You are interested in the equipment that was used? H. W. GRAHAM-No, just the product. R. C. Buehl-The product was in granular form, of a shape very similar to that of the ore used. Using minus 10-mesh ore, the product is essentially minus 10-mesh, mixed with the coal and dolomite. It is then passed through a belt type of magnetic separator, which picks up the magnetic iron and allows the dolomite and coal to fall off. If the coal is sufficiently valuable, it can be separated from the dolomite and, provided the coal has a sufficiently low ash content, it can be reused. For instance, if a low-ash reducing agent like petroleum coke is used, it can be reused until all the carbon is consumed. H. W. Graham-That clears the point for me. I was not quite sure whether the experi-

Jan 1, 1947

By J. H. Wernick, S. Geller

A number of new AB, compounds, in which A is a rare earth or yttrium atom and B is Al, Mn, Fe, Co, or Ni, having the cubic MgCu, structure (Laves phase) are reported. In most of the compounds, the interatomic distances are normal; the lanthanide contraction is observed. However, in the compounds CeB2, B = Fe, Co, Ni, Ce appears to have a valence substantially greater than three; in CeAl2, Ce appears to be trivalent. These results are interpreted as vesulting from an energetically more favorable situation for the 4f electron of Ce to be lost to the 3d band of Fe, Co, nnd Ni. Evidence for the existence of homogeneitj! ranges in these compounds is presented. THE purpose of this paper is to report on the crys-tallographic investigations of a large number of new compounds, Table I, with the MgCuz structure (cubic Laves phase). It is a part of a continuing study of the magnetic properties and structures of binary systems involving the rare earths. In a previous paper' some of the magnetic properties of such systems were reported briefly. We have also reported2 a number of compounds of the CusCa type. The compounds were prepared by induction melting in Argon atmosphere of mixtures of stoichiomet-ric amounts of the constituent elements.* For most of the compounds fused alumina or silica crucibles were used as the containing vessel; graphite crucibles were used to prepare CeA12, NdAl2 and TbA12. X-ray powder photographs were taken with CrKa radiation and the use of Straumanis-type Norelco cameras of 114.6 mm diam. The compounds AB2 belong to space group Fd3m-Ol with 8A in a): (000; 01/2 '/2;3) + 000-; b % XA and 16B in dl: (000; oVa %; 3) + 5/87; % %; 7e % Vs\£>. Because the intensities of the reflections on the powder photographs of the different compounds are similar, relative intensities were computed only for DyMnz for CrKa radiation, Table 11. In the calculation of intensities, the Thomas and umeda3 atomic scattering factors, corrected for dispersion,4 were used. The agreement between observed and calculated intensities leaves little doubt that DyMnz has the MgCuz structure. Crystallographic data for the ABz compounds are given in Table JII. Twelve of these compounds have been reported by other authors. A comparison of the published results with our work is given in Table W.* ers of elements of lower purity, to peritectic reactions in some cases, and to the presence of homogeneity ranges in these alloys, so that melting losses would still result in single phase alloys. The possibility of existence of homogeneity ranges in these compounds was investigated systematically only for GdMnz. At room temperature, the solid solution range is between

Jan 1, 1961

By T. D. Murphy

This chapter deals with those types of silica raw materials that have been segregated and refined by natural processes into nearly monomineralic deposits and hence, by virtue of their high degree of purity, have become the sources of commodities having special and somewhat restricted commercial uses. In some instances, these raw materials occur in nature as unconsolidated quartzose sand or gravel and can be exploited and used with very little preparation and expense. More often, they occur as sandstone, conglomerate, quartzite, quartz mica schist, or massive igneous quartz which must be crushed, washed, screened, and sometimes chemically treated before commodities of suitable compositional and textural characteristics can be successfully prepared. The occurrence and distribution of silica raw materials is summarized and an effort has been made to bring commodity definitions, critical properties, and specifications up to date. Presentation of mining and processing methods is considered beyond the scope of this article; they are, for the most part, conventional and well known. New production techniques are currently reported in the trade journals and are later adequately described in technical publications as promptly as competitive restrictions allow. Discussion on Basis of Use ABRASIVE USES Industrial silica used for abrasive purposes falls into three main categories: (a) blasting sand; (b) glass-grinding sand; and (c) stone-sawing and rubbing sand. Blasting sand is a sound closely-sized quartz sand which, when propelled at high velocity by air, water, or controlled centrifugal force, is effective for such uses as cleaning metal castings, removing paint and rust, or renovating stone veneer. It is commonly referred to as Sand Blast sand. Multicycle quartz sand is an efficient blasting agent by merit of its survival characteristics which are soundness, toughness, and hardness. Steel grit and shot have supplanted it to a large extent but owing to their higher cost and tendency toward deterioration in storage, are still not universally used. It is conceded that angularity promotes faster cutting but this is offset by a higher loss in fines. The peening action of a rounded grain is a desirable feature in achieving a satin finish for certain light metal castings but a subangular grain is unsurpassed for fast heavy cutting. Specifications are chiefly based on size frequency distribution but it is mandatory that the grain be free of adhering clay or irony coatings. Material that dusts upon handling will not be tolerated. There is no uniform trade designation for the many blasting sand grades. Most producers sell on the basis of numbered grades; that is, No. 1, No. 2 and so on, this generally connoting fine to coarser grades. Designation of grade by the two sieve sizes between which most of the material lies, is practiced in some areas. Thus, in a No. 1220 grade, 98 pct of the material passes a 12 mesh sieve and is retained on a 20 mesh sieve. Blasting sand specifications vary according to use. Coarse grades range from 4 mesh to 12 mesh, medium grades range from 12 mesh to 30 mesh, finer grades may range from 20 mesh to 100 mesh or finer. Specifications generally call for narrow limits of gradation, requiring precise sizing methods. The fact that most blasting sands are retained

Jan 1, 1960

By J. E. Schiller, S. E. Khalafalla

Due to its unique surface properties, magnesium oxide (MgO) is an excellent medium to filter asbestos and other suspended solids from water. MgO operates up to twice as long as a sand filter before backwashing is required while flow rate and filtrate clarity are as good or better with MgO.

Jan 1, 1984

By A. C. Freeze

The first use of electric punched card accounting machines as an aid in calculating reserves at the Sullivan mine in Kimberly, B.C., was made in January, 1948. At that time their use was limited to totalling individual reserve blocks for the various reserve classes and for calculating total metal content. The immediate objective was to increase speed, improve accuracy, and to effect some savings in labor that could be employed more usefully elsewhere. It was recognized also that the potential for achieving even greater advantages was excellent. The initial experiment proved so successful that it was inevitable that the use of the method would expand. Thus, for the past nine years assay data from core hole and development headings have been processed by these machines and the results integrated with the program of calculating reserves. It was also learned that the machines could store and classify a large amount of other information concerning the mining characteristics of each reserve block in addition to tonnage and metal content. This has proven very useful for the preparation of monthly production reports as well as in long term planning, in forecasting production schedules, and in analysing the results achieved.

Jan 4, 1961

By Charles W. Tandy, Wm. I. Weisman

Sodium sulfate is an important industrial chemical, being one of perhaps a dozen or so chemical commodities that are produced and consumed in the United States in quantities exceeding one million short tons per year. In recent years over half of the country's production of sodium sulfate has come from natural sources, whereas 20 years ago only 25% was derived from these sources. Production of natural sodium sulfate from various types of deposits is the main source of this chemical in Canada and Mexico, and probably in Argentina, Chile, and the USSR. [Table 1] illustrates the growth in production of natural sodium sulfate in the United States. Mineralogy and Physical Properties Sodium sulfate is widespread in occurrence and is a common constituent of many mineral waters, as well as seawater. Many of the saline or alkali lakes throughout the world contain varying amounts of sodium sulfate. In its natural form it is found as the hydrous salt, mirabilite, commonly called Glauber's salt, and as thenardite, the anhydrous variety. The largest quantities occur in the form of mirabilite. Sodium sulfate is found in varying degrees of purity, from theoretically pure efflorescent crystals of mirabilite to combinations and admixtures of other salts and impurities. It is a common constituent of some brines, and it is from this source that much is extracted commercially. Sodium sulfate is also found combined with other compounds, such as the mineral glauberite, the double salt of anhydrous sodium and calcium sulfate, and blödite, the double salt of sodium sulfate and magnesium sulfate. While these and other minerals containing sodium sulfate are not economically important, they are of interest because of their frequent occurrence. The reader is referred to other publications (Cole, 1926; Dana, 1932; Grabau, 1920) for descriptions of these minerals. Only the two economically important minerals, mirabilite and thenardite, will be described herein. Mirabilite, Na2SO4 • 10H2O, contains 55.9% water of crystallization. It is noted for its efflorescence or spontaneous loss of water. On

Jan 1, 1975

By Ta M. Li

In Gila County, Ariz., the Jaquays Mining Co. still finds the mining of asbestos a worthwhile and economical venture. At a time when domestic productive capacity is being reduced because of rapidly rising costs and tough environmental dust standards, this firm has dramatically brought its mine and mill operation into full productive capacity and compliance with both Federal and State regulations. Jaquay's Mining Corp. owns four underground mines in the Tonto National Forest, located approximately 32 miles north of the Globe-Miami District in Arizona. Only one mine, the El Dorado, is presently active. It mines an estimated 45,000 tpy of ore and waste. From this figure about 3000 tpy of fiber (No. one crude to Grade 4T) and fiberized shorts (No, seven) are recovered at the firm's mill, located in Globe, Ariz. Based on current ore reserves, the El Dorado mine has an estimated life between 15 to 17 years, assuming current mining rates and stable market conditions.

Jan 3, 1975

By A. M. Gaudin, D. W. Fuerstenau, M. M. Turkanis

SOLUBLE silver salts are effective activators for flotation of sphalerite with potassium ethyl xanthate as collector.' Since sphalerite takes up large quantities of silver ions rapidly," investigation of this system appeared fruitful for studying the mechanism of sphalerite activation and deactivation. Experimental data presented here comprise studies of the mechanism and rates of activation and deactivation of sphalerite with silver and cyanide ions. A 20-lb sample of sphalerite from Ottawa County, Oklahoma, was handpicked, crushed, screened, hydrosized to produce a 65/100-mesh fraction, and purified by electrostatic separation. The sphalerite was then leached with benzene and absolute ethyl alcohol to remove possible organic contaminants and with 0.1 M NaCN to remove any copper that might have been picked up during screening. The benzene had been specially purified by grinding with fine sphalerite for 12 hr to remove trace impurities that might have had a specific affinity for sphalerite. Finally, the mineral was washed, dried in flowing nitrogen, and stored in large ground-glass stoppered weighing bottles under a small nitrogen pressure.

Jan 1, 1957

(Under this heading will he published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Member, mining engineer, technical education with 9 years' varied experience as superintendent and operating engineer, desires position with mining or manufacturing company requiring the services

Jan 3, 1918

By N. G. W. Cook

When an excavation is made underground the original rock stresses are removed from the surfaces of the excavation. These surfaces converge to partially close the excavation and the superincumbent rock mass moves down towards the excavation. If the convergence of the surfaces of the excavation were controlled, energy generated by their motion against the controlling forces could be extracted. Since the total forces in the rock mass are not significantly affected by the excavation, stress concentrations arise around the excavation, which compensate exactly for those stresses no longer transmitted through the excavation. These phenomena give rise to two general principles which provide the basis for analyzing the effects of making any underground excavation. The first of these is that the total force resulting from the stresses across any plane in the rock, including any plane through the excavation, must be the same before and after the excavation is made. The second of these is that energy must necessarily be released as a result of making an underground excavation. It is instructive to consider the implications of these two principles for two extreme cases of material behavior between which the actual behavior of rock must lie, namely, the behavior of a fluid and the behavior of an elastic solid. For the purpose of analysis in this paper, an underground excavation is defined as an excavation in which the smaller horizontal dimension of any open void at a particular horizon is less than the depth of that horizon below surface. In the case of a fluid, any unsupported excavation would fill immediately, as a fluid cannot sustain shear stresses. For the same reason, stress concentrations could not arise and the forces across any plane would necessarily be the same before and after excavation. If the filling of the excavation were controlled by forces applied to the surfaces of the excavation, an amount of energy equal to the product of the fluid pressure

Jan 1, 1967

Jan 1, 1951

By R. G. Johnson

The prevailing system of locating wells on a rectangular basis, as shown in Fig. 1-A, has developed because of the exigencies of offsetting at boundary lines. When, however, a very large tract is being drilled, it is often possible to abandon this inferior method for the superior arrange- ment known as "staggering," which is illustrated in Fig. 1, B and C. The advantages of the triangular over the rectangular method are evident from Fig. 2, computed on the basis of one well to 10 acres (4 ha.). With the triangular system, no land is more than 409.4 ft. (124.8 m.) from a

Jan 1, 1920

B. F. TILLSON,* Franklin, N. J.-A preliminary study of this paper did not, in my case, succeed in checking with the shovel dimensions of one of the large shovel manufacturers. I therefore raise a question as to there being some difference in standards used by different manufacturers in regard to the dimensions of the shovels for similar sizes and styles, so it may be rather confusing to some of us when we attempt to use the table in this paper and classify the capacity of the shovels as given here with some that are on the market.

Jan 4, 1919

By Philip R. Whitney

Deposition of manganese oxides is of common occurrence in streams of the north-eastern United States. Manganese entering the stream in solution in ground water is oxidized and deposited in the stream, primarily as oxide coatings on detrital materials. Prevalence and thickness of the coatings increases with increasing particle size in the coarse sand and gravel range. A number of metals of economic and environmental interest are enriched in these coatings. Samples of 8 to 16 mm pebbles were obtained from two streams in the Shawangunk region of southeastern New York State, an area of know71 Pb/Zn/Cu mineralization. The pebbles were leached to remove the oxide coatings and the resulting solutions analyzed for Mn, Fe, Pb, Zn, Cd, Cu, Co, and Ni. Trace-metal/Mn ratios in these streams are generally one to two orders of magnitude higher than regional background values. Profiles of trace- metal/Mn ratios along the streams show considerable detail; contributions of metals from tributaries are sharply reflected in the metal content of the oxides. The potential advantages and disadvantages of using coated stream gravel for geochemical prospecting and environmental studies are discussed in the light of these and other data.

Jan 1, 1976

By Gifford White

CONSIDERABLE attention has been directed in recent years to methods of electric prospecting other than the conventional direct-current tech-niques. It has been extensively recognized that electrical data of a more general nature than that possible by direct-current methods might be useful in geophysical studies. To this end, a number of different types of electric currents have been employed, such as single-frequency alter-nating currents, square-topped periodic current waves,4 periodic surges of a less specific nature,8 and suddenly applied direct current.1,2 Yet, to the author's knowledge, little analysis of these different types of driving currents has been made from the standpoint of network theory to determine just what type of currents would give the most useful data, and, most important of all, to determine the relation of the data taken by one method to those of another. Without touching on the actual theoretical problem of how currents flow in the earth under specified boundary conditions, some very useful information can be obtained from the study of the fundamental integral equations of electrical networks, throwing light on the problem not ordinarily appreciated by the field worker. Some manipulation of the standard network equations will be made, with the sole purpose in mind of developing expressions leading to practical results. Suppose that four points in the earth have been located and it is wished to obtain the most useful type of electrical data by inserting current into two of them and measuring the potential developed between the other two. The first problem that arises is that of which pair of the four shall be chosen as current grounds. In the direct-current case, where only steady potentials are measured, the selection is of little consequence, but as soon as currents varying with time are used at the current grounds, a new effect arises. The fact that a varying current is flowing in the current-carrying conductor between the current grounds means that magnetic and electric fields varying with time will be produced

Jan 1, 1940

By C. E. Gregor

Current modern trends in mining show that hoisting shafts are being expected to fulfill an important ventilation function. However, where rigid guides and supporting structures are mandatory, ventilating power costs will be high, unless the transverse structures (shaft sets) are streamlined. In the complex configurations of hoisting shaft furniture patterns, either for original design purposes, or for the adjustment of an existing shaft, a useful degree of aerodynamic optimization, by reduction of overall resistance, can only be effectively evaluated by model studies in a special purpose wind tunnel, as described herein. The author has shown that, in one particular case, an annual power cost saving of more than $50,000 was indicated, mainly by the selection of buntons and dividers of improved aerodynamic profile. Mining companies are now realizing the advantages that can accrue through proper attention to the aerodynamic aspects of mine shaft design. With progressive demands of civilization for an ever greater supply of coal and metals, and with greater depths of working, higher rates of extraction, advanced degrees of mechanization, and improved standards of environmental health and work comfort, shaft design is becoming an extremely important aspect of mining operations. In addition, because the cost of sinking, equipping, maintaining, and operating a mine shaft is continually increasing, there is a greater incentive to use a shaft for the maximum duty, consistent with economy. The current natural tendency is therefore to sink multi-purpose shafts, to install as much equipment as is safely and effectively possible to operate; and then, over and above all these functions, to use the shaft to its maximum possible ventilating capacity, as a major, or auxiliary, airway. Clearly, this latter additional function can only be employed at a significant cost, since the most economic operating airways are smooth-lined and devoid of internal rigid furniture. It is true that hoisting functions can be carried out in such shafts if rope guides are used, but only under restricted conditions. Where a manway must be provided, fixed guides and supporting structures are mandatory, and ventilation costs become accentuated. It is generally recognized that the prime element of cost in ventilating a mine can be represented by the power required to drive the fan unit. It is also known that the largest component of total mine resistance is that of the downcast shaft, where this shaft is equipped with rigid guides for hoisting purposes. The pressure loss varies directly as the resistance of the shaft, in accordance with a modification of the Atkinson equation p = RQ2/3600. Furthermore, the air horsepower drawn is given by the equation AHP = (p x 0/33000. Therefore, the power required to drive the fan unit varies as the resistance of the shaft and the cube of the air quantity. Clearly, if Q is a specified minimum, then the only way to minimize the pressure loss (and the power costs) is to reduce the shaft resistance R. (See Table I for a list of symbols.) The resistance to airflow of a shaft equipped with rigid guides and supporting structural sets consists of two components which, for the sake of analytical simplicity, can be regarded as additive. 1) Frictional resistance, represented by the viscous frictional forces within the boundary layer, as air flows along the surfaces of the walls and the periphery of the vertical elements (guides, pipes, cables, ropes, etc.) of the furniture. The friction loss can be readily calculated by the Atkinson equation, after selection of a suitable value for the friction factor K from the McElroy compilation.' KxLxO xQ2 5.2 xA3 Friction loss can be minimized by lining the shaft walls (particularly if of circular or elliptical cross-section) with a smooth continuous lining of monolithic concrete.

Jan 1, 1968