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By Sidney A. Swensrud

MUCH discussion has occurred as to the use or uses which might be made after the war of either or both .of the large diameter (24 inch and 20 inch) War Emergency pipe lines built by y the United States Government during the war, to move crude petroleum and refined products such as gasoline and light distillate fuels. Indeed, the disposition and future use of these lines constitutes, in the minds of many people, one of the most important problems of postwar readjustment in the Oil Industry. The two lines, running from points in Texas to the New York-New Jersey-Philadelphia area, were constructed only because of the inability during the war to continue normal ocean tanker movements from the Gulf Coast to the East Coast. Physically they could continue after the war to move crude or refined products, and it appears that lines of such large diameter as these, if operated at or near capacity, could move these liquids at costs per barrel which might be considered in the same general cost range as for tanker movements.1 If, therefore, we were to look forward at the end of the war to a shortage of tankers, it is probable that the continued use of these pipe lines for petroleum movements to the East Coast would be worth considering, as against building new tankers to take over the movement, provided there were no other economic or national defense reasons for restoring tanker fleets and no other better use for the pipe lines. Because of the extensive tanker construction program which has been and still is in progress, and because of our Navy's marked success in combating the submarine problem, it appears to be quite possible, however, that instead of a shortage of tankers at the end of the war, we may have a surplus instead. If this should turn out to be the case, then there would seem to be considerable doubt that these lines would continue to be used for moving petroleum or products to the East Coast at the expense of tying up tankers. It would hardly seem probable that the owner of any such tankers would ship via one of the large lines at the expense of tying up one of its own tankers, unless the pipe line tariff rate charged was lower than the out-of-pocket cost of operating a tanker as against the out-of-pocket cost of keeping it tied up. And considering that a substantial part of the cost of operating a tanker goes on even when it is tied up, it is very difficult to figure out how any pipeline tariff could be established that would be low enough to compete with individually owned tankers that otherwise would be idle. Certainly a pipe line tariff rate high enough to cover direct costs plus even a low rate of depreciation and return on the investment would be far above the out-of-pocket tanker operating costs. In view of these considerations, it has seemed desirable to examine with some care some of the various alternatives that have been suggested as to other possible uses to which these lines might be put. One of these is for transportation of natural gas to the New York-New Jersey Philadelphia area. This Eastern area, located at the destination of these lines, contains the heaviest concentration of population in the United States, and is not now served with natural gas. At the other end of the lines lie the greatest discovered natural gas reserves in the United States, if not in the world, and many

Jan 1, 1944

Jan 1, 1912

Jan 1, 1916

Jan 1, 1900

By Russell C., Fleming

FOK, many years the officials of the Magma Copper Co. mine at Superior, Ariz., have had to contend with adverse conditions underground in the form of high rock temperatures, hot water, and high relative humidity. These conditions in the mine have been such that working the mine would have been impossible were it not for the constantly expanding and improved sys- tem of ventilation to produce bearable conditions in the working places. Results that have already been achieved make an interesting study of what can be done along those lines. From the time the mine was first opened in 1910 it has been hot. An idea of the conditions that have persistently been encountered can be obtained from parts of the mine that are not being worked at present or that do not yet have sufficient ventilation. Virgin rock temperatures as determined in drill holes at the faces range from 104° to 116°*. An observation made at the face of No. 5 West footwall drift on the 2800-ft. level.

Jan 1, 1930

By R. J. Corfield

MODERNIZATION of the entire electrical system and improvement of Rotation process efficiency is the twofold goal of the improvement program underway at the Arthur and Magna concentrators of the Utah Copper Div., Kennecott Copper Corp. Copper ore from the Bingham pit goes to these two concentrators where an interlocking program calls for complete electrical modernization and increased flotation process efficiency through additional capacity and flow scheme revisions. Flotation plants at the two mills are essentially duplicates, and while this article deals with the changes at the Arthur mill similiar improvements are being made at the Magna mill.

Jan 3, 1953

By C. G., Fink

The dissolution of gold by cyanide solutions was studied by determining the time required for the solvents to dissolve gold leaf. Minute traces, even 0.5 ppm, of sulphide ion retard the dissolution of gold, and this behavior cannot be accounted for by the presently accepted hypotheses involving oxygen-depletion or thiocyanate formation. On the other hand, traces of the salts of lead, bismuth, mercury, and thallium considerably accelerate the dissolution. The beneficial effect of lead is dependent upon the pH and cyanide ion concentration of the solution.

Jan 1, 1950

By John Mullen

Impingers TWO types of midget impinger apparatus are used at Climax. The Mine Safety Appliances Company's midget impinger (MSA) and the Climax Molybdenum Company's midget impinger (CMC) (Fig. I). The Leiman Brother's No. 25, positive displacement pump is used in the CMC impinger instead of the four-cylinder radial pump that is used in the MSA impinger. With the MSA apparatus it is possible to obtain the proper vacuum by adjusting the needle valve on the vacuum chamber, while with the CMC impinger the proper vacuum is obtained by varying the rate at which the pump is cranked. The Leiman Brother's No. 25 pump is built to displace 0.1 cu. ft. of air per min. when operated at 145 r.p.m. In the CMC impinger this pump is so geared that the required crank speed is approximately 59 r.p.m. Both types of impinger apparatus are equipped with a water gauge mounted on top of the case and they are calibrated and operated in reference to the gauge. The MSA impinger flasks and nozzles are used with both types. Calibrating Impingers A calibrated precision Sargent wet-test meter (Fig. 2) is used in calibrating the impinger apparatus. The apparatus is set up as for taking a sample in the field, except that the hose from the outlet side of the meter is attached to the impinger nozzle. One revolution of the large hand of the meter indicates 0.1 cu. ft. of air displaced. The impinger pump is cranked for one minute, therefore, at a rate that will cause the large hand of the meter to make one revolution. The gauge reading is noted, then the impinger is cranked at this rate for 10 min. and is checked for error. If the meter indicates that more or less than I cu. ft. of air has been displaced, the impinger must be cranked—ither slower or faster according to the error—for another 10 min. and again checked for error. This operation is repeated until the proper gauge reading for a sampling rate of 0.1 cu. ft. per min. has been determined. This gauge reading is used in all sampling operations until the impinger is again calibrated. An impinger is calibrated at least twice each week. MlCROPROJECTOR A Bausch and Lomb model B micro-projector is used (Fig. 3). It consists of a substantial metal base supporting the light source and a microscope. Illumination is provided by a Bausch and Lomb 4.5-amp. arc lamp with mechanical feed. A glass water cell filled with a heat-absorbing and color-filter solution is placed between the arc lamp and the microscope. Two types of solution have been found satisfactory— a 2 per cent solution of copper sulphate or a 2 per cent solution of picric acid and distilled water. This percentage may be varied to give the desired color to the light reflected upon the screen. Any standard microscope may be used. A Bausch and Lomb microscope with

Jan 1, 1946

By S. S. Raymond, C. R. Hayward

In reheating quenched steel to remove part of the hardness, the softening effect has generally been considered to be a function of temperature and time. The temperature effect is well known, and long before pyrometers were heard of the blacksmith was able to do a good job of tempering, by rule-of-thumb methods and experience in judging temperatures. Modern conditions, which demand steel that will withstand the severest tests, require that the heat treatment be carried out with every possible precaution to secure the best results obtainable. Pyrometers and heat-treatment furnaces of many types are on the market and improvements are continually being made so that it is now possible to regulate the temperature in heat treatment very accurately. There is still a question regarding the time that the steel should be subjected to treatment. It is customary with all operators to insure the desired temperature throughout the specimen and it is generally supposed that a longer treatment of a hardened steel produces a further softening but there are few published figures showing the exact effect of time of treatment at constant temperature. A search of the literature disclosed several brief statements that the tempering effect was a function of both time and temperature, but in no case were any figures given. The opinion is very generally held that the well-know tempering colors are accurate indicators of the degree of tempering. This is disputed by Brearley (The Heat Treatment of Tool Steel, page 102) who states: It has been said that the result would be the same in respect to both hardness and other properties whether the colors were obtained by a shorter heating at a higher temperature or a longer heating at a lower one. This, to say the least, is a very doubtful conclusion, and is certainly not borne out by mechanical tests on oil-hardened and tempered motor car steels which, after tempering for periods varying from 15 min. to 2 hr., show no very great bifferences. The present investigation had for its object the obtaining of some definite data regarding the effect of time, which might serve as a guide to those engaged in the heat treatment of steel. The Rhode Island Tool Co. cooperated by furnishing the steel and machining the test specimens.

Jan 1, 1917

By Brahm Prakash, R. Schuhmann

Chemical conditions for flotation and nonflotation of quartz with oleic acid as collector and barium, calcium, aluminum, iron, and tin as activators were studied using a simple vacuum-flotation technique in glass-stoppered graduates. The detailed study of barium activation led to an interpretation based on ideal Langmuirian chemisorption.

Jan 1, 1950

By Rees D. Rawlings, C. W. A. Newey

The aging characteristics of an Fe-11 at. pct Mo alloy have been studied by means of light metallography together with density, Young&apos;s modulus, and hardness measurements. The results were consistent with the precipitation of a single intermetallic compound during aging; overaging was slow relative to that in other iron-based binary alloys. The solution treatment temperature had a small effect on the rate of hardening whereas deformation prior to aging had a marked effect on both the rate of hardening and the peak hardness. The density data indicate that the compound precipitated is Fe3MO2 and not the Laves phase Fe2Mo. Analysis of the modulus and density results gave values for the time exponent for precipitate growth of approximately 1.0 and 1.5 for the alloy aged with and without prior deformation, respectively. DETAILED studies of precipitation hardening in bcc matrices have been confined largely to the effects of carbides and nitrides. In view of this and the growing technological interest in intermetallic compound strengthening, e.g., in maraging steels, a study of precipitation in iron-based alloys with a low interstitial content has been undertaken. This paper is concerned with the aging behavior of an Fe-11 at. pct Mo alloy; the mechanical behavior of the alloy will be reported later. The early work of sykes on Fe-Mo alloys showed that precipitation of the intermetallic compound was accompanied by an increase in hardness and a decrease in volume of the material. More recent surveys of the strengthening associated with precipitation have been made3-5 and, in particular, Elsen and wassermann4 showed that deformation prior to aging increased the rate of hardening. These latter workers also followed the precipitation process by means of dilatometry, electrical resistivity, and lattice parameter measurements. Their results confirmed that there is a decrease in volume on aging. Except for the work of Hornbogen on an Fe-20 at. pct Mo alloy, neither clustering nor the precipitation of a nonequilibrium phase has been observed in Fe-Mo alloys. Studies of alloys of lower molybdenum content475 indicate that the equilibrium intermetallic compound is precipitated during aging. However, there is some doubt concerning the nature of the equilibrium precipitate phase. According to the phase diagram constructed by Hansen,8 the phase should be precipitated. This phase has a rhombohedra1 crystal structure which is characterized by the formula Fe706,&apos; although the composition of the molybdenum-rich boundary corresponds approximately to Fe3Mo2. The version of the diagram proposed by Sinha, Buckley, and Hume-Rother indicates that the A phase, a Laves phase Fe2Mo, should be precipitated. Their observation of a Laves phase supports the earlier findings of Bechtoldt and Vacher,13 although, in a recent study of the system by means of diffusion couples, Rawlings and Newey did not detect the phase. The work presented here describes the effect of solution-treatment temperature, aging temperature, and prior deformation on the aging characteristics of the alloy as revealed by light metallography together with hardness, density, and Young&apos;s modulus measurements. In addition the density data are used in an attempt to determine the compound precipitated during aging. EXPERIMENTAL PROCEDURE A 29-kg ingot of the alloy was cast at R.A.R.D.E., Fort Halstead, from deoxidized, Japanese electrolytic iron and sintered molybdenum. The ingot was homogenized for 6 hr at 1473°K and then worked, with intermediate anneals, into 6- and 16-mm-diam rods and 6-mm plate. Chemical analysis of the alloy gave, wt pct: Mo, 17.5 (11 at. pct); C, 0.003; Si, 0.002; S, 0.005; P, <0.002; and02, 0.0098. Solution treatments were carried out under a dynamic argon atmosphere in a vertical, "crusilite" element, furnace which had a facility for rapid quenching into iced water. Except for the study of the effect of solution treatment temperature, all specimens were solution-treated at 1573" * 2°K for 1 hr. Salt baths were used for the aging treatments. Specimens for hardness, density, and Young&apos;s modulus measurements were produced, after heat treatment, from the stock rod or bar using a precision silicon carbide slitting wheel. As described later, the quenching treatment produced local plastic strain in the stock material; consequently, care was taken to ensure that the specimens were not prepared from these regions. Those specimens used in the studies of the effects of prior deformation on the aging behavior were strained in compression in a Denison universal testing machine. Specimens for light metallographic observations were mechanically polished on successively finer grades of diamond paste down to and then etched in either alcoholic ferric chloride or in a 2 pct nital solution. Vickers diamond pyramid hardness data were obtained using a 30-kg load. At least five impressions were averaged for each determination. Density measurements were made using a displacement technique in which each specimen was weighed in air and in dibromoethane at 296°K. The specimens were cylindrical and weighed 3 to 4 g; all weighings were made on a balance reading to 1 x 10"5 g. For each specimen the mean value of five weighings was used to calculate the density. The density of the dibromoethane was determined using the displacement procedure and a standard nickel specimen. The error in an absolute density value was estimated to be HI.01 pct. To obtain the density as a function of aging time a single specimen was used and the density meas-

Jan 1, 1969

By A. D. McMaster, M. L. Gimpl, N. Fuschillo

Low-power, high-speed, radiation-resistant, monolithic thin-film integrated circuits require thin-film resistors of high sheet resistance which are compatible with the processing requirements for monolithic silicon devices. For this purpose the structure and electrical resistance as a function of temperature were investigated for Nichrome-silicon monoxide cermet films on passivated single-crystal silicon substrates. A suitable material was found to be a mixture of 50 vol pct Nichrome-50 vol pct silicon monoxide. This mixture, when evaporated onto 300°C substrates. showed a low temperature coefficient up to 400°C, at both 270 and 1100 ohms per square. Resistors deposited on room-temperature, 300°, and 500°C substrates were heat-treated at 600°C in air for short periods of H- seed, low-power, radiation-re sis tant, monolithic thin-film integrated circuits&apos;-3 require thin-film resistors of high sheet resistance and low temperature coefficients of resistance which are compatible with the processing requirements for monolithic silicon active devices. The present investigation is directed towards the replacement of the Nichrome in the sandwich-type SO2-Nichrome-SiO resistors, currently used for DTL monolithic thin-film integrated circuits, with codeposited Nichrome-SiO cermet resistors. These Nichrome-SiO resistors are provided with an overcoat of SiO and are deposited onto thermally oxidized silicon wafers used in monolithic mi-crocircuit technology. The cermet resistors are shown to provide a lower temperature coefficient of time totaling up to 45 min. Electron nzicrogvaphs and diffraction patterns were taken of the as - deposited and heat-treated films. These results were then compared with electrical-resistance measurements for each condition. The room-temperature and 300°C substrate films showed a large decrease in resistance. The 500°C substrate film remained stable throughout the entire cycle. Electron-microscopy results show that the increased stability after heating to 600°C is largely due to crystallization of the films which begins in the vicinity of 400°C. The slight oxidation of the films when heated in air had a negligible effect on the resistance. The resistance of the film was a function of the substructure. resistance and a more versatile compatibility with silicon monolithic processing. Previous work3, on chromium-SiO coevaporated cermet resistors on glass and ceramic substrates without overcoats of SiO has been reported. For the present application, the thin films should possess the following ideal requirements: a) a temperature coefficient of resistance as near zero as possible up to 300°C; b) have a sheet resistance higher than 200 ohms per sq to conserve space on the chip; c) be easy to evaporate; d) be oxidiation- and radiation-resistant; e) show long-time stability at 100°C; } be stable in N2 atmospheres up to 600°C for short periods of time (5 to 45 min). Requirements a to e are well-known. The last requirement was optional and was due to a mask elimi-

Jan 1, 1967

By Allen Johnson

WITH a realization of the rapidly increasing importance of automatic stokers as a medium for domestic heating, the Anthracite Institute Labo-ratory has conducted extensive investigations, over a period of several years, to determine the various outstanding characteristics of stoker design and performance. The purpose of this paper is to summarize these findings as a guide to current practices. STOKERS INVESTIGATED One or more models of the underfeed stokers listed below were included in the various phases of this investigation: Beckley Gilkoal Burnwell Iron Fireman Combustioneer Motor Stokor Electric Furnace Man Norristown Super-Stoker Erie Heat Generator Whitney Fire Ball (Tests Incomplete.) Fuel Saver Principles of Construction.-The operating principle of the leading makes of underfeed stokers is similar (Fig. 1). A plungers, or slowly revolving worm2, conveys the buckwheat or rice sizes of anthracite to the center of a specially constructed tuyere pot where air is admitted to the coal. through suitable ports of varying design. As the fuel burns, it is slowly forced to the outside circumference of the tuyere by the pressure of the incoming coal; eventually the ash falls over the edge of the pot, either entirely by gravity or aided by mechanical sweepers. In at least one model, the entire firepot revolves. While various special details have been included in the design of a number of stokers, they do not affect the ,general principles as described above, and therefore have not been included in this discussion.

Jan 1, 1935

Jan 1, 1922

Jan 1, 1922

By A. L. Sweetser

EXPERIENCE has shown how difficult it is to obtain information regarding laboratory-tests in connection with the chlorination-process for the extraction of gold from its ores, and I therefore present the following method, somewhat in detail, for the benefit of those who may desire to pursue research work in this field. The ore chosen was a partly-decomposed porphyry, extremely siliceous and comparatively soft, and of an average value per ton of from $25 to $26 in gold and $0.68 in silver. The chemical analysis gave : Fe2O3, 3.35; FeS, 1.5; MnO2, 0.75; ZnCO3, 4; Al2O3, 3.20; H2O, 0.7; SiO2 and insol., 83.50 per cent. The ore, first crushed to pass a 5-mesh screen, was coned and quartered until a 45-lb. sample was obtained. Samples for assay and analysis, taken from this lot by means of riffles, were crushed to pass a 100-mesh screen. The original sample was divided into 10-lb. lots, of which one was crushed to pass a 10-mesh screen; another through a 12-; the third through a 20-, .and the last through a 30-mesh screen. Because of the production of an excessive quantity of fine material it was deemed inexpedient to crush finer than 30-mesh size-a decision the wisdom of which is proved by the data in Table I., showing the increasing ratio of slimes, in proportion as the ore is crushed finer. In order to determine the percentage of fines in the sizes of mesh selected, a weighed sample of ore was taken from each mesh, and a sample from the 10-mesh lot was passed successively through 20-, 40- and 100-mesh screens, and the percentage remaining on each screen determined. This process was repeated with the 12-, 20- and 30-mesh lots, with the results given in Table I.

Sep 1, 1907

By B. M. Larsen, T. E. Brower

For some years we have been carrying on a rather comprehensive investigation of the occurrence of oxygen in liquid open-hearth steel. This investigation was interrupted by the war emergency and is therefore incomplete, with many questions still answered only partially, if at all; yet it seemed worth while to present a report of progress on this difficult field of research, if for no other reason than to promote discussion and further investigation of this important problem. The significance of such studies depends in large measure upon the accuracy of measurements of oxygen content in liquid steel while it is still in the furnace or as it flows into the ladle, or thence into the mold and there is, as we shall show, good reason for believing that the main source of uncertainty is in the sampling, not in the analytical method as such. The difficulty arises from the fact that any method of sampling is of itself apt to alter the amount of oxygen in solution in the liquid steel, because this oxygen is in a readily reactive condition. On the one hand, being usually present at a concentration appreciably in excess of that corresponding to equilibrium with the carbon then present, it may decrease rapidly in percentage by reaction with carbon and evolution of CO, especially if the liquid metal is in any way shaken or brought in contact with a cooler solid surface. On the other hand, it may increase rapidly by ab- sorption of oxygen from a slag, a furnace atmosphere, or from air. These circumstances, which are inherent in the problem, as well as our conclusion that, despite the considerable amount of careful work already done, there is still no method of sampling liquid steel acceptable as an unquestioned standard, ed us to undertake systematic comparisons of oxygen content of large numbers of samples taken: (I) by a single method at different positions and levels in the bath; (2) at the same place by different sampling methods; and (3) from bath, tapping stream and pouring stream. The different sampling methods yield somewhat different values and there is as yet no way to tell with certainty which is the most accurate. But the general reproducibility and consistency of the results give us some confidence in certain inferences we draw from them: namely, that the "spoon" method of sampling, properly carried out, gives somewhat more consistent results than the "bomb" method, as it has usually been practiced; that, in the bomb method, an aluminum cap is preferable to a steel cap; that the oxygen content of liquid steel in a finished heat is substantially the same all over the bath at the same level, and tends to decrease at lower levels further from the slag interface; also that it tends to decrease, and to decrease erratically, from furnace bath to tapping stream entering the ladle. Accordingly it seemed desirable to report these observations in detail as a first step, so that the reader may judge their significance as a contribution towards solution of the main problem, which is to find a means of pre-2

Jan 1, 1945

By John L. Lamont, Walter Crafts

ADEQUATE hardenability has long been recognized as one of the first requirements for producing desired mechanical properties in a heat-treated steel. Since the introduction of the Jominy end-quench test1 and the development of correlative information to expand its use, industry has had an effective measure of hardenability. Prediction and control of the hardenability have been made possible by Grossmann&apos;s principle2 for calculating hardenability from chemical composition; and Field&apos;s conversion3 from depth of half-martensite hardening to Rockwell C hardness has made the relation more quantitative. These developments have facilitated the design of new steels and the control of standard grades to the extent that it has been possible to establish tentative hardenability bands for some of the more commonly used alloy steels.4 As the depth of hardening of the Jominy test specimen is usually measured by Rockwell C hardness, it was considered that it should be possible to predict the hardness by a more direct calculation. It has been found that this can be accomplished by the addition of Rockwell C units proportional to the carbon and alloy content, grain size, and position in the Jominy test specimen. The calculation has been found to be fairly accurate, and because of its additive character is relatively simple to use. In principle the method of calculation is somewhat similar to the expressions developed by Herty, McBride, and Hollenback,5 Burns, Moore, and Archer,6 and Burns and Riegel.7 The calculation is started from a base that includes the effects of carbon content and position in the Jominy test speimen. Rockwell C units are added to the base in proportion to the alloy content and grain size. This sum represents the Rockwell C hardness up to the level at which a disproportionate increase of hardness is caused by the formation of martensite, and above this level an increment for martensite hardening is added. The effects of alloys are directly proportional to the amounts present and are independent of each other, the carbon content, and the position in the specimen. Furthermore, the factors for determining the martensite increment are dependent only on carbon content and are independent of cooling rate and alloy content. It is this absence of interrelation between the different factors that makes it possible to calculate the hardness and makes the method of calculation consistent with the principle that the character of the hardening reaction is governed primarily by carbon and that alloys exert their effect chiefly through control of the critical cooling rate. The principle of the calculation, and the effects of alloys on the critical cooling rate,

Jan 1, 1945

By AIME AIME

MORE than thirty members of the Coal Division attended the Coal Land Valuations Round Table on Monday morning. Chairman Dilworth stated that the Committee had been appointed to take up the question and, after reading the list of members of the Committee, pointed out that the object of the meeting was to formulate a plan of action rather than to discuss any phases of valuation, per se. To this end he presented a tentative outline of points to be considered in the future by the Committee. After a lively discussion on the desirability of inclusion of some questions in the agenda of the Committee, the following outline was adopted :

Jan 1, 1931

By R. L. Tobie

The degree of automation that has evolved in the dumping and hoisting of ore at the 3A and 3B hoisting shafts of the San Manuel mine is discussed. Motormen underground now dump their own trains at shaft pockets with rotary car dumps which operate semiautomatically. The ore is then drawn out of the 1200-ton shaft pockets into measuring baskets in skip loading stations, loaded into bottom-dump skips, hoisted, and dumped into coarse ore bins on the surface, in a fully automated operation. In an underground control room on the 2075 level midway between 3A and 3B shafts, car dumping, skip loading, and hoisting systems are monitored on lighted control panels which mimic each step in the operation. Here skip loading and dumping are viewed on closed-circuit television.

Jan 1, 1972