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By D. H. Thompson, A. W. Tracy

E. A. ANDERSON*—At the outset, I note that you are using a humid atmosphere containing ammonia but that you make no reference to the variable of carbon dioxide content. Edmunds in his work in this laboratory found very marked effects on the rate of failure due to variations in carbon dioxide in the environment. This point is, of course, strongly related to the overall corrosion rate problem since the role of the carbon dioxide seems to be to permit the formation of hygrogroscopic salts which give a controlled moisture film on the specimen surface, which in turn seems to support the intergranular penetration more consistently than would otherwise occur. (2) Your results with various copper binary systems are very striking. It is curious, however, that the time-to-failure minima all occur at percentages of the alloying element which are considerably below the solubility limits as given in the conventional equilibrium diagrams. If your theory regarding the presence of these impurities in some concentration in the grain boundaries is correct, then either the existing diagrams are not accurate in the room temperature region, or there is a difference in solubility in the grain boundaries as compared -with the grains. A study along these lines might be very revealing. (3) The undesirable effect of silicon in copper calls to mind our own observations on the influence of silicon on the stress corrosion cracking resistance of alpha brass. In this case, silicon was found to have a very marked beneficial effect, particularly when a heat treatment capable of producing a grain boundary constituent was used. I should appreciate it if in the discussion of your paper this point should arise, you would attempt to clarify the difference between the copper-silicon binaries and the copper-zinc-sili-con ternary alloys. D. H. THOMPSON and A. W. TRACY (authors' reply)—(1) We have no data on the constancy of the carbon dioxide content of the air used for the test atmosphere but have believed that the normal carbon dioxide content of the air was as constant as could be obtained by using Edmunds' method of removing carbon dioxide from the air and then adding a measured quantity. In any event, the test atmosphere was the same for all specimens in a test run. We agree with Mr. Anderson that the carbon dioxide content is important in the formation of a hygroscopic film on specimens. (2) We can imagine that there could be a concentration of solute atoms at the grain boundaries which would be so small that present methods would not detect it even if it exceeded the solubility limit of the alloy. There could be somewhat greater solubility at the grain boundaries for an interstitial solute. There is a possibility that phosphorus dissolves in this way but we believe that none of the other solutes studied does. In our present studies we hope to find out something about conditions at the grain boundaries of some of the systems mentioned in the paper. (3) Mr. Anderson points out that silicon brass, which has had a high temperature heat treatment followed by a quench. is highly resistant to stress-corrosion cracking. Although the test conditions used by Anderson* et al were different from our test conditions, it is noted that the silicon brasses which had not had the special heat treatment were less resistant to stress-corrosion cracking than copper containing approximately equal amounts of silicon. G. R. GOHN†—Nonferrous metallurgists and particularly, materials engineers, have been accustomed to thinking

Jan 1, 1950

By David R. Maneval, Sylvester Lemezis

All acid mine drain waters, regardless of source, share certain characteristics; but they do differ in exact chemical composition, degree of acidity, and total solids content. Any serious program to treat such waters must recognize these differences and apply to each specific case the technique which offers the best promise of each specific case the technique which offers the best promise of technical and economic success. The Pennsylvania Dept. of Mines and Mineral Industries has originated and funded studies of many different treatment means. Neutralization with lime is now being used on 200 different polluted streams in Pennsylvania, and multistage flash evaporation has been selected for a particularly large and troublesome outfall near Wilkes-Barre, Pa. A 5 x 106 gpd plant for this latter site is now being designed by Westinghouse Electric Corp. which developed a concentration process based on multistage flash evaporation as part of the State's research program.

Jan 1, 1973

SEC. 1. The membership of the Institute shall comprise seven classes, namely: 1. Members; 2. Honorary Members; 3. Senior Members; 4. Associates; 5. Junior Members; 6. Rocky Mountain Members; 7. Junior Foreign Affiliates. All shall be equally entitled to the privileges of membership, excepting that no member of any class whose residence shall be outside of the United States of America, except those residing in Mexico and Canada, shall be entitled to vote. SEC. 2. Members: A person to be eligible for election or transfer into the class of Member must be at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy, or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. This shall not apply to Rocky Mountain Members.

Jan 1, 1946

SEC. 1. The membership of the Institute shall comprise seven classes, namely: 1. Members; 2. Honorary Members; 3. Senior Members; 4. Associates; 5. Junior Members; 6. Rocky Mountain Members; 7. Junior Foreign Affiliates. All shall be equally entitled to the privileges of membership, excepting that no member of any class whose residence shall be outside of the United States of America, except those residing in Mexico and Canada, shall be entitled to vote. SEC. 2. Members: A person to be eligible for election or transfer into the class of Member must be at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy, or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. This shall not apply to Rocky Mountain Members.

Jan 1, 1946

By A. Blake Caldwell

In 1936 the Ertsberg story began and its development is a classic example of the courage it takes to discover one mining prospect and bring it into production. Truly, the finding and working of this mine is a modern exception to the overwhelming odds every modern prospector must surmount to be successful. Today, it takes lots of time, plenty of money and the tenacity of a bulldog to whip the laws of nature. Ertsberg ("ore mountain" in Dutch) is literally an elliptically shaped plug of magnetite which erosion has exposed for 560 ft above ground level. The deposit has been likened to an ice cream cone with the outcrop the ice cream, which is above ground, and with the cone buried below the surface. Assaying about 2.5% Cu, the 33 million tons of ore also carry 0.025 oz Au and 0.265 oz Ag per ton.

Jan 1, 1970

By G. T. Murray

The aging behavior of a Cu-Ti (3.2 at. pct Ti) alloy has been followed by electrical resistivity, hardness, and metallographic changes. The resistivity data indicate two principal processes, the first causing a sharp decrease in resistivity, and the second, which occurs over a long period of time, a much smaller rate of decrease. Lamellar nodules, Widmanstätten platelets, and homogeneous continuous precipitation was observed. The Widmanstätten platelets grow at the expense of the latter. When this study was initiated, little information was available on the aging behavior of copper-base titanium alloys. Several articles'-3 that appeared in the early 1930's showed that these alloys could be strengthened by precipitation, but a detailed study was not made. Within the past year, however, two other more comprehensive studies4'5 have been reported in the literature, one consisting primarily of an investigation of mechanical properties, the other

Jan 1, 1961

By G. W. Mao, A. M. Gaudin, D. W. Fuerstenau

Activation of sphalerite with copper salts has long been thought of as a chemical reaction of the following form: ZnS + Cu++ [=] CuS + Zn++ [ 1 ] Early experimentation1-3 showed that the reaction seemed to be stopped by the coating of insoluble copper sulfide, but since the analytical methods were crude, it was only surmised that the reaction could proceed by diffusion. Probably the most conclusive evidence for reaction (Eq. 1) was obtained by Cooke,4 who found a stoichiometric replacement of Zn++ by Cu" after 50 days' reaction at about 100°C. Cooke also found the sphalerite to be covered with a rather thick coating of covellite, which in¬dicates that activation is a continuing replacement of Zn++ by Cu" rather than diffusion of Cu" throughout the sphalerite lattice. However, the occurrence of diffusion at high temperatures has been observed.5,6

Jan 4, 1959

By Jasper Johnson

Taken in all its bearings there is, perhaps, no more interesting coal-field than that locally known and designated as " Wilmington," both on account of the superior qualities of its product as a household and steam fuel, when compared with other Illinois coal, and its geological position. The territory underlaid with coal, to which this name was originally given, embraced a very small area, including only the south half of sections 31 and 32 (township 33 north, range 9 east) in Wilmington township, and sections 5, 6, 7, 8, 17, 18, 19, 30, and 31, with occasional outliers in sections 3, 4, and 9, and, possibly, in sections 20, 28, 29, 30, and 32 (township 32 north, range 9 east) of Reed township, in Will County, comprising eleven square miles of workable coal within the known basin. Borings indicate the presence of coal on sections 30 and 33 in Wilmington

By Jasper Johnson

TAKEN in all its bearings there is, perhaps, no more interesting coal-field than that locally known and designated as " Wilmington," both on account of the superior qualities of its product as a house- hold and steam fuel, when compared with other Illinois coal, and its geological position. The territory underlaid with coal, to which this name was originally given, embraced a very small area, including only the south half of sections 31 and 32 (township 33 north, range 9 east) in Wilmington township, and sections 5, 6, 7, 8, 17, 18, 19, 30, and 31, with occasional outliers in sections 3, 4, and 9, and, possibly, in sections 20, 28, 29,30, and 32 (township 32 north, range 9 east) of Reed township, in Will County, comprising eleven square miles of workable coal within the known basin. Borings indicate the presence of coal on sections 30 and 33 in Wilmington

Jan 1, 1875

By Richard F. Miller

The investigations of large-grained specimens carried out by Polanyi and Schmid,l Sykes,2 Goucher,3 Yamaguchi,4 Gough, Cox, and Sopwith,5 Carpenter and Elam,6 Aston,7 and others have shown qualitatively that grain boundaries restrain the deformation of adjacent crystals. But whether or not the influence of the grain boundary is confined to the glide planes intersected by the boundary has not been demonstrated in any of these investigations, nor has there been carried out any quantitative analysis of the influence of a boundary on the deformation of a crystal. Indeed, the specimens employed in the previous work contained so many complicating factors that it would have been difficult to observe any variation of the extent of the influence of the grain boundaries in relation to their sizc. The specimens were small, the grain boundaries irregular and at no particular angle to the specimen axis or the

Jan 1, 1934

By Arnold H. Kackman

At the Kaiser Cement and Gypsum plant near San Jose, Calif., one rod-ball mill has taken over the entire raw grinding function for the largest single cement operation in the West. Installed as part of a major overhaul performed on the plant by Kaiser Engineers, the new mill does the work of seven previous mills in feeding the plant's six kilns and keeping pace with its annual capacity of 8.5 million bbl of cement. Installation of the mill, which is the largest in the world, was started in December of 1966 and completed in April of 1967. The over-all modernization program surrounding the new mill has included the modification of existing crushing facilities; the building of new raw materials handling and blending facilities, new raw milling facilities, and new slurry handling facilities; and the installation of a digital-analog control system.

Jan 7, 1967

By Thomas P. Forbath

THE sudden realization that known sulphur reserves amenable to mining by the Frasch hot water process are nearing exhaustion focused attention on widely scattered surface deposits throughout the world. These deposits are not necessarily of lower sulphur content than ores located underneath Louisiana or Texas salt domes which usually aver- age about 30 pct sulphur disseminated in limestone matrix. Their near surface occurrence, however, renders exploitation by the Frasch process impossible. As is well known, the Frasch process depends on the presence of 500 to 1000 ft of overburden and cap rock above the sulphur deposits to permit melting underground sulphur in place by diffusing hot water under pressures of 200 to 600 psig in the formation and raising the molten sulphur to surface by air lift. This process renders possible the production of pure sulphur which is 99.5 pct pure without any subsequent treatment.

Jan 9, 1953

By Albert Sauveur

The instrument about to be described meets so perfectly the special needs of the metal microscopist that there eeeme to be little doubt but its merits must be readily appreciated by those who have had any experience in the microscopical examination of metals. The Microscope-Stand.—The microscope-stand proper, Fig. 1, consists of a microscope-tube, provided with both coarse and fine adjustments of the best construction, and with a draw-tube, rigidly mounted on a bar supported at both ends on substantial and firm cast-iron legs. The height between the table and the under side of the supporting bar is 5 in. and the distance between the supporting legs 12 inches. This arrangement affords free space below the objective for the examination of large epecimens of metals, such as full rail-sections, without detracting in the least from the value of the

Jan 1, 1912

BOSTON SECTION R. L. AGASSIZ, Chairman, - JAMES G. CARLETON, Vice-Chairman, E. E. BUGBEE, Sec.-Treas., Mass. Inst. of Technology, Cambridge, Mass. W. E. C. EUSTIS, G. A. PACKARD. The forty-fifth meeting of the Boston Section was held, at the Engineers' Club, on Tuesday, Nov. 6, 1917. Mr. F. C. Carstarphen, tramway engineer of the American Steel and Wire Co., was the guest of the evening. After dinner, Mr. Carstarphen gave a most interesting illustrated talk on the subject of aerial tramways. The views-showed the various forms of aerial tramways and three' unique installations, one carrying 285 tons of coal an hour, undoubtedly the maximum quantity transported by any tramway up to this time. The second installation is that of a lumber-carrying tramway, 5 miles long, operating in California. The last views illustrated a 13 ½ -mile tramway for carrying salt over the

Jan 2, 1918

By R. Neilson Clark

THE coal-beds of Canyon City are situated six miles below the town, upon the Arkansas River. At this point the Rocky Mountains have thrown out from their main ridge two spurs. The one to the north, containing Pike's Peak and Cheyenne Mountain, is known as part of the "Rim Range;" the one to the west and south is known as the "Greenhorn Range." Against these syenitic mountains, the later rocks are piled and uplifted ; at right angles to the direction of this main uplift is the axis of a lesser plication. On the north, west, and south, the pitch is steep, gradually flattening as it approaches the centre of the basin and rising again to the east at a pitch of about 5", thus forming a perfect basin, the centre of which is only three miles east of the base of the Greenhorn Range.

By I. N. Zavarine

THE observations presented in this paper were recorded during a study of the spheroidizing process. Spheroidization of cementite in steel is either brought about to develop a set of desirable mechanical properties or is an incidental result of mechanical and heat-treating manipulations. Physical properties of steel are materially influenced by the state of the cementite. Conversion of cementite from the lamellar to the spheroidal state is usually accom-panied by a decrease of hardness and of strength and by an increase in ductility. The spheroidized structure is usually considered as an ultimate step in the process of the softening of steel. The unorthodox hardening of a 3.5 per cent Ni steel (SAE No. 2330) after a heat-treatment that previously proved entirely suitable for a complete spheroidization of cementite in carbon steels led to the observa-tions that constitute the subject of the present paper.

Jan 1, 1939

By I. E. Rosenzweig

THE problem considered in this paper is as follows: An arbitrary horizontally stratified area is given. The electrical properties of this area are characterized by a function p(z) (Fig. 1), which shows the relationship between resistivity p of thes oil and the depth z. For such general case the apparent resistivity p* will be computed, by FIG. 1.-GRAPH OF FUNCTION p(z) FIG. 2.-GRAPH OF p(Z) FOR n HOMO-GENEOUS LAYERS. earth-resistivity measurements carried out by any given configuration of electrodes. General solutions of this problem appear to be very important for interpretation of field results of resistivity measurements, concerning structural investigations. Such solutions have been given by many authors for the special case of a finite number of homogeneous layers (Fig. 2)1-4 as well as for the more general case of continuously rang-ing resistivities. 5-8

Jan 1, 1939

By Jack D. Arthur

The Surface Mining Control and Reclamation Act of 1977, as amended, and related regulations take blasting safety into consideration by requiring compliance with existing state and federal laws. The regulations are based on blasting practices developed by the industry, as well as research and experimentation by the US Bureau of Mines and explosive manufacturers. Residential areas in the proximity of surface mines have made it mandatory that blasting operations be conducted under restrictions and requirements designed to protect the public and structures located within 0.8 km (0.5 mile) of any surface blasting activities. Restrictions against blasting apply where dwellings, schools, churches, hospitals, or nursing facilities are within 305 m (1000 ft) of blasting operations. They also apply where wells, petroleum or gas storage facilities, municipal water storage facilities, fluid transmission pipelines, gas or oil collection lines, and sewage lines are within 152 in (500 ft) of blasting operations.

Jan 11, 1979

By J. H. Berryman

THE use of oxygen as a bath reagent in hearth furnaces during the refining period is a familiar story. Investigations and tests in which oxygen was substituted for iron ore to reduce carbon date back 25 years and include the work of Bigge,1 Browne,2 and Chelius.3 During this past year the majority of the experimental work in the use of oxygen was carried on mainly in open-hearth shops, since it was felt that the greater field for application lay in this type of furnace. Much constructive work was done in evaluating the carbon-oxygen relationships, as reported by Slottman and Lounsberry4 and by Hughes.5 Steelmakers using the electric furnace have been actively engaged meanwhile in an experimental program of their own, with such success that the oxygen injection pipe has become a tool in the day to day production of low-carbon and stainless steels.

Jan 1, 1947

By I. Stapf

Systematic investigations on silver-rare earth metal systems have been extended on the Ag-Ce system in order to clarify the discrepancies reported in literature. The phase diagram has been reinvestigated on the base of thermal analyses and of microstructure examination on cast and annealed specimen. All intermetallic phases Ag4Ce, Ag3Ce, Ag2Ce and AgCe show no extended range of homogeneity, they melt congruently fm), or decompose peritectically (d) at 815 °C (d), 1030 °C (m), 855 °C (d) and 855 °C (m), respectively. The system shows eutectics at 793 °C/10 at.%, 780 °C/42 at.%, and about 505 °C/81 at.% Ce. d-Ce dissolves up to 2 at .% Ag and decomposes metatectically at 710 °C. Furthermore, the phase transformation of the intermetallics would be clarified. The phases Ag5Ce and Ag51Ce14 reported in literature could not be verified.

Jan 1, 1984