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By John T. Galey

Production of crude oil for 1940 in southwestern Pennsylvania was off nearly 70,000 bbl., largely as a result of the great number oi abandonments, together with the lack of extension of the Washington and Green County pools. Oil wells completed numbered 51, which is 26 more than last year, but the total initial production of 259 bbl. is only 18 bbl. greater than in 1939. There was an increase of 72 over last year for a total of 209f gas wells. However, 68 7 dry holes were drilled, which is 40 more than a year ago. Thus, 328f wells were drilled during the year, and rigs are erected or drilling is progressing on 59 t more. Shallow Development Oil.—Butler County led in number of oil wells completed, with a total of 27 for an initial production of only 69 bbl. Washington County, with 12 new oil wells, one of which made 40 bbl. from the Fifth sand in S. Franklin township, has 95 bbl., while in Allegheny County 9 wells gave an initial of 86 bbl. for the highest Per well average in the area. This initial was given a considerable boost by one 35-bbl and another 2;-bbl. well in West Deer township, where the Fourth sand produced at 1840 feet. Greene County had only one oil well completed during 1940, and Washington County had 12. The subnormal totals for these counties may be explained by the higher cost of completions and the declining price of crude. The first price change in crude during the year occurred on May 22, when a 25 cut was made. A second 25 cut was made July 12, and was followed by a 156 cut on .Aug. 28. This price held until Nov. 12, when there was a restoration of 156. On Dec. 17 a second 156 increase was put into effect, bringing the price to $I.So per barrel. Gas The large increase in the number of gas wells completed may be attributed to three factors; namely, the recently discovered production possibilities of moderately deep, hitherto little tested horizons, together with increased demand and price. The latter has been made possible by a recent decision of the court, which ruled restraining the public service Commision's prohibition of a raise in the minimum monthly charge to small consumers by one of the major gas companies. A portion of the revenue derived in this manner is being passed along to the producer in the form of higher prices in the field. This higher field rate will remain in effect until a new ruling is made, when it will be reduced in proportion to the reduction of the monthly minimum charge. In an effort to extend the chambers Dam Fifth sand oil pool southwest from Amwell township, Washington County, several wells have been drilled. One of these, in Morris township, washington County, had an initial of 3.2 million cu. ft. open flow from the Big Injun sand. This indicates an entirely new productive area for the latter horizon. Allegheny County had one spectacular well in South Fayette township-—at a depth of about 2500 ft. a 4-million-CU. ft.

Jan 1, 1941

By John T. Galey

Production of crude oil for 1940 in southwestern Pennsylvania was off nearly 70,000 bbl., largely as a result of the great number oi abandonments, together with the lack of extension of the Washington and Green County pools. Oil wells completed numbered 51, which is 26 more than last year, but the total initial production of 259 bbl. is only 18 bbl. greater than in 1939. There was an increase of 72 over last year for a total of 209f gas wells. However, 68 7 dry holes were drilled, which is 40 more than a year ago. Thus, 328f wells were drilled during the year, and rigs are erected or drilling is progressing on 59 t more. Shallow Development Oil.—Butler County led in number of oil wells completed, with a total of 27 for an initial production of only 69 bbl. Washington County, with 12 new oil wells, one of which made 40 bbl. from the Fifth sand in S. Franklin township, has 95 bbl., while in Allegheny County 9 wells gave an initial of 86 bbl. for the highest Per well average in the area. This initial was given a considerable boost by one 35-bbl and another 2;-bbl. well in West Deer township, where the Fourth sand produced at 1840 feet. Greene County had only one oil well completed during 1940, and Washington County had 12. The subnormal totals for these counties may be explained by the higher cost of completions and the declining price of crude. The first price change in crude during the year occurred on May 22, when a 25 cut was made. A second 25 cut was made July 12, and was followed by a 156 cut on .Aug. 28. This price held until Nov. 12, when there was a restoration of 156. On Dec. 17 a second 156 increase was put into effect, bringing the price to $I.So per barrel. Gas The large increase in the number of gas wells completed may be attributed to three factors; namely, the recently discovered production possibilities of moderately deep, hitherto little tested horizons, together with increased demand and price. The latter has been made possible by a recent decision of the court, which ruled restraining the public service Commision's prohibition of a raise in the minimum monthly charge to small consumers by one of the major gas companies. A portion of the revenue derived in this manner is being passed along to the producer in the form of higher prices in the field. This higher field rate will remain in effect until a new ruling is made, when it will be reduced in proportion to the reduction of the monthly minimum charge. In an effort to extend the chambers Dam Fifth sand oil pool southwest from Amwell township, Washington County, several wells have been drilled. One of these, in Morris township, washington County, had an initial of 3.2 million cu. ft. open flow from the Big Injun sand. This indicates an entirely new productive area for the latter horizon. Allegheny County had one spectacular well in South Fayette township-—at a depth of about 2500 ft. a 4-million-CU. ft.

Jan 1, 1941

By C. F. Jenkins, G. V. Smith

Serrated plastic flow in stable austenitic alloys based on Fe/Ni has been shown to be related to the presence of carbon and/or chromium in the systems. Strength peaks and plateaus in the serrated-flow temperature region for a commercial alloy correlate with an increased dislocation content, arising, presumably, from enhanced multiplication as a result of a strong interaction between dislocations and solute atoms. The data generally support a mechanism controlled by migration of vacancies, with the energy for vacancy motion being modified by the presence of chromium. Chromium atom -dislocation interaction is responsible for effects above 500°C, whereas the defect interacting with dislocations between 200" and 500°C is suggested to be a carbon-vacancy Pair. ThE phenomenon of jerky flow, serrated flow, or the Portevin-le Chatelier (P-C) effect in austenitic stainless steels is usually attributed to substitutional at1,2 mospheres1,2 or to precipitates&apos;-4 which form at dislocations during plastic deformation. On the other hand, evidence exists which supports a direct inter-stitial-dislocation interaction mechanism for serrated flow in fcc Ni-C,5,6 Ni-H7-9 and in nickel-austenites containing carbon." The present work consists in a study of serrated plastic flow in stable austenitic al-loys. The effects of carbon and of chromium were investigated separately, and a commercial stainless steel with different levels of interstitial impurity concentration was studied in an attempt to delineate the combined effects of the alloying elements. EXPERIMENTAL TECHNIQUES a) Materials and Fabrication. A commercial AISI 330 stainless steel and several specially prepared aus-tenitic alloys have been studied. The experimental alloys were prepared by arc melting the constituents under purified argon. Analyses of the materials are given in Table I. The commercial alloy was obtained as 5/8 in. bar stock and rolled to 0.092 in. sq, with several intermediate anneals. At this stage some of the material was annealed in Pd-purified hydrogen at 1100°C to establish different levels of interstitial content. All other heat treatments were in vacuum (10-5 torr). The "pure" alloy ingots were swaged to 0.120-in. rod and annealed in Pd-purified hydrogen at 1100°C. The analyses for these conditions are also contained in Table I. Following the above treatment, the final wire sizes Table I. Chemical Analyses of Test Materials Hrin Hydrogen at Cr, Ni, Alloy 1lOO°C wt pct wt pct C, ppm* N, ppm* Type 330 As-received 14.78 33.25 430 300 Type 330 64 14.78 33.25 40 50 Type 330 200 14.78 33.25 27 21 Fe/35 Ni 72 - 35.10 <10 62 Fe/35 Ni 200 35.10 <I0 44 Fe/35 Nil15 Cr 72 14.95 34.94 <I0 61 Fe/35 Ni/15Cr 200 14.95 34.94 <10 45 Fe/35 Ni/C $ 35.OM 380 *Sensitivity: N t 5 ppm Ct10ppm. f Nominal Ni content. % A master NiC alloy was used in preparation of this material; courtesy of D.E. Sonon. were obtained by either swaging or cold drawing. The test results did not vary with these techniques. b) Specimen Preparation. Two sizes of specimen and two gripping systems were used. i) 0.070-in. wire with a chemically milled gage section: 0.75 in. long, 0.060 in. in diam. These were fastened into grips containing tapped grooves. ii) 0.050 in. wire, gage length 1.5 in. Ball bearings were welded to the ends of the wires and the gage length was taken to include all material between the welds. Socket-type grips were used with these specimens. With specimens of type ii), joining was performed in a specially constructed brass jig, under argon, and automatic timing was utilized in the procedure. No adverse effects of welding were noted. Specimens were encapsulated and solution treated for 1 hr at temperatures selected to produce the same average grain size, -50 µ. Annealing twin boundaries as well as normal crystal boundaries were counted. The temperatures used are listed in Table 11. Table 11. Specimen Size. Temperature of Heat Treatment and Resulting Grain Diameters for Test Materials Recrystallization Resulting Material Condition Temperature Grain Sue AISI 330 Not H purified 0.070 120O°C 45 to 55µ in, wire AlSl 330 H , pure, 0.070 in. 1150°C 45to55µ wire Fc/35Nil15Cr Pure, 0.070 in. wire 1000°C 45tossp Fe/Ni Pure. 0.070 in. wire 775°C 45 to 55µ Fe/Ni/C Pure, 0.050 in. wire 850°C 10 to 20p AlSl 330 Not purified, 0.050 1150CC 45to55p in. wire AlSl 330 ti, pure, 0.050 in. 1150°C 45to55p wire

Jan 1, 1970

By Gilbert E. Doan

WHEN metallurgists and other engineers meet their college classmates or former teachers, the conversation will frequently become reminiscent and finally turn to engineering education. These graduates have tested the value of their college training in the hurly-burly of the outside world so respectful attention is due their opinions, which, strangely enough, fall into two opposite categories. A member of one group expresses a deep-seated conviction that engineers should have a fuller foundation of physical chemistry, another asks for a more thorough training in mathematics, others wish a more thorough grounding in refractories, a series of courses in petroleum engineering, or in electric welding. Each alumnus of this group

Jan 1, 1937

By Thomas T., Read

ALTHOUGH the first colonists in the area that is now the A United States, whether Spanish, French or English in nationality, were usually keenly interested in the possibilities of mineral wealth, it is a curious and interesting fact that none of them happened upon the mineral deposits that eventually were to make this the greatest mineral-producing country; up to 1800 it would probably have been rated as rather poor in minerals. Spanish explorers traversed the southeastern United States with- , out finding the Appalachian gold deposits that aroused so much interest in the early nineteenth century; Coronado sought in vain for the seven golden cities of Cibola; and the important gold \ deposits of California were not discovered until the political sovereignty of the region had passed from Mexico, which had held it for three centuries. The French also held Canada for nearly two centuries (and the British for another century) without finding the mineral deposits in Ontario and Quebec that now are so important. Though they knew of the copper of the Keweenaw peninsula, the lead ores. of Wisconsin and Missouri, and the coal of Illinois in the seventeenth century, these deposits were all too remote for exploitation. In the area held by Great Britain, iron smelting was planned at Jamestown as early as 1619 and was actually begun at Lynn, Mass., in 1643. The industry grew slowly, at first, but had reached considerable importance before the Revolution. Commercial bituminous coal mining began about 1750 in Virginia but anthracite mining in Pennsylvania was not started until 1800. As a result there was naturally little interest in the technical aspects of mineral prodnction here before 1800 by any except the few people who were actually engaged in it. Students of natural science were much interested in minerals, however. The activities of those who rank as geologists are so thoroughly covered in

Jan 1, 1941

By AIME AIME

NO MORE SUITABLE time and place than LOS Angeles on Thursday and Friday, July 28 and 29, could have been chosen for the Western Regional Meeting of the~1nstitutk. After attending two clays of technical sessions and enjoying the luncheons and dinners of the meeting, visitors, on the following days, could see the opening ceremonies and events of the Olympic Games, which started on July 30 and continued to Aug. 14. Such d spectacle can be seen only once in a generation in this country.

Jan 1, 1932

By Percival Roberts

I DESIRE to present this evening a few notes from the standpoint of a manufacturer upon the subject of tests of iron for structural purposes; not that I have any new facts to which to call your attention, but rather a statement of a few of the objectionable features of the present modes of operation, showing the absolute necessity of important and very radical changes. At the present time, as most of you are well aware, proposals for materials are accompanied by certain specifications as to quality and tests to which the manufactured article must conform. Evolved in many cases from the inner consciousness of some one more expert in theory than in practice, we find a few of the specifications to be good, many bad, and some indifferent. Appended are specimens of specifications of the most prominent engineers and railroad companies, which may be taken as representing the best and most intelligently framed specifications which we now have, arid yet in some pints scarcely satisfactory, owing to misunderstanding of tests as now made. To show the very varied opinions held as to proper quality of iron for bridge-work, I give the tests of two lots of fron made by inspectors with the results, which were referred to the maker with the following commensts : Lot No. 1. Teat of Iron for Eyebars. Reduced area. Elongation. Size. Per cent. Per cent. Breaking load. 4" x 1 3/8 26 25 68,500 Bent 120° around 1 1/2" bar with fracture. Reduced area. Elongation. Size. Percent. Percent. Breaking load. 6" x 1 7/15 24 24 48,820 Bent 110° around 2" bar. This iron should bend 180° without fracture, and is therefore rejected. Lot No. 2. Test of Iron for Brirlye. All measurements taken upon a parallel section of 10". Iron for tension members. Breaking load Elongation. size. per aquare inch. Percent. 1 5/8 49,600 20 14 61,600 27

Jan 1, 1882

By P. H. Metzger, D. W. Fuerstenau

The activation of sphalerite was found to occur at a much lower rate with Pb++ then with Cut++ or Ag+. To prevent activation with Pb++, the ratio [m in solution must approximate 103. An example is given illustrating how this condition is met in practice through the addition of zinc sulfate and soda ash. In selective lead-zinc flotation, the mill operator, especially the one who is concentrating a partially oxidized ore, often must add zinc sulfate and/or soda ash for effective depression of the sphalerite. In the present paper the authors show how this practice prevents the activation of sphalerite in the presence of Pb++. A number of years ago Gaudin (1) postulated that Zn++ might control the activation of sphalerite with Pb++ through competitive adsorption. However, recent experimentation has shown the activation of sphalerite with Ag+ and Cut++ to be a chemical reaction in which silver or copper ions replace zinc in the sphalerite lattice through the formation of a more insoluble sul-fide (2,3,4) Thus, if activation with Pb++ is similar to that with Ag+ or Cu t+, zinc salts should control the activation of sphalerite not through competitive adsorption but because the ratio of [zn++/Pb++] in solution regulates the extent of the chemical exchange between Zn++ and Pb++ in the solid phase. The objective of this investigation has been to study the kinetics and equilibrium conditions for the uptake of Pb++ by sphalerite and to investigate the prevention of lead activation with zinc salts. BASIC PRINCIPLES Sphalerite activation has been shown to be a replacement reaction wherein a less soluble compound is formed at the expense of the more soluble zinc sul-fide (2,3,4) For example, if sphalerite is placed in an aqueous silver nitrate solution, ZnS gives to the solution more S= than can exist together with Ag+, and hence the following reaction takes place: ZnS + 2 Ag+? Ag2 S + Zn ++; k = [zn ++]/[Ag ++]2 = 10 26 (1) Therefore, ZnS will dissolve in the presence of Ag+ and activation of sphalerite with Ag+ will proceed after monolayer coverage by solid state diffusion until equilibrium conditions are reached in the system (2, 4) Because of the large difference in the solubility of ZnS and Ag2S, zinc salts cannot affect the reaction unless a complexing agent, such as cyanide ions, is present to complex Ag+ more tightly than Zn++ . By complexing Ag+ and Zn++ in solution, the uptake of Ag+ by sphalerite can be regulated by controlling the ratio m. . Experimentally (2) it was found that the activation of sphalerite by Ag+ could be prevented through the addition of NaCN if this ratio reached a value of approximately 10 26. The mechanism of sphalerite activation with copper salts is given by the following reactions: ZnS + Cu ++ ? CuS + Zn + + ; (2) k = [Zn++]/[Cu++] = 10 11 ZnS + Cu + ? Cu2S+ Zn++; (3) Experimentally Mao (3) found that the activation of sphalerite with Cu++ or Cu + was prevented if the ratios expressed in Equations 2 and 3 were approximately l09 and l022, respectively, with cyanide ions as the deactivator. Although zinc salts do not affect the activation of sphalerite with silver or copper ions in the absence of a complexing agent, activation with lead ions theoretically can be controlled by the addition of zinc salts because of the relatively small differences between the solubility of ZnS and PbS (5). Equilibrium

Jan 1, 1961

By Francis Church Lincoln

I. SITUATION AND SURROUNDINGS. THE Promontorio mine is situated at the northern end of the Sierra San Francisco de Coneto, in the town of Promontorio, Partido of El Oro, State of Durango, Mexico. As shown in the sketch-map, Fig. 1, the nearest railroad station is Chinacates on the Mexican International Railroad, 82 miles north of the city of Durango. The mine is 16 miles north of the station by air-line. It is reached by means of a good wagon-road which first crosses the Guatimapé Plain, passing the ranches of San Antonio and San Julian, to Estacion-a distance of about 15.5 miles-and then entering the mountains crosses the Sierra to Promontorio-a further distance of 11.5 miles¬making in all a distance of 27 miles by road from railroad to mine. Promontorio is just beyond the summit of the range, at an elevation of about 8,000 ft. above sea-level, or 1,350 ft. above the Chinacates station. The Castillo de San Francisco, the highest peak in the Sierra, has an altitude of 10,000 ft., and the Promontorio road crosses the summit of the ridge at an elevation of 9,000 ft. by a pass just below this peak known as the Puerto del Almagre. The Promontorio mill is situated at Santa Ives, 2 miles by tram or 3 miles by wagon-road to the north of Promontorio and about 600 ft. lower. The Sierra San Francisco de Coneto decreases in height towards the north and west till it comes to an end at the Melchor Arroyo on the ranches of Melchor and Ramos. Beyond this arroyo another range, the Sierra de la Candela, begins. In the vicinity of the Promontorio mine the hills are very rugged and the surface is furrowed by ravines which contain running streams during the rainy season-July, August and

Jan 1, 1908

By Robert Forsyth

As the latest plant on a large scale, the new Bessemer works of the North Chicago Rolling Mill Company, at South Chicago, presents some features of interest to steel-makers, I have ventured to lay before the Institute a short description of that plant, and some* remarks upon the practice there. At the time the South Chicago works were designed the adoption of the basic process in this country seemed imminent. Experience in Europe had demonstrated the perfect success of the process technically, and the question of its commercial value was one which, for any particular works, would have to be settled by its special advantages for procuring the necessary ores and basic materials. Under the circumstances, it was thought best at South Chicago to so arrange the plant as to allow the introdnction of the basic whenever it became advisable, and to make such other changes from the standard type of Bessemer plant as the state of the art seemed to demand and to foreshadow. As the use of metal direct from the blast furnace, while generally condemned by experts here, was in such successful practice in Europe (particularly in connection with the basic process), there was no doubt about its feasibility, while its economy in fuel and labor made it especially attractive to the Western manufacturer. It was accordingly decided to build a direct-metal plant adapted to the basic process. The ingots made were to be rolled into rails at one heat, and were to be of such size (12 inches square and long enough for three and four rails) as to be readily and quickly handled by the rolling machinery proposed. This small size of ingots, and the large number cast from each heat of 10 tons, made it necessary to provide a good deal of room in the casting-pit—much more than in any previons plant—and to put down extra facilities for handling ingots. To meet the delays incident to the basic process—to insure that one vessel should be always blowing if necessary, and to provide opportunity for current repairs to linings, etc.—it was decided that three vessels should be used, and, to properly concentrate the work of

Jan 1, 1884

By Dever Ashmead

ANTHRACITE was first mined in the Wyoming Valley and sold as an article of commerce in 1808. As some preparation has always been necessary to make it ready to burn, the preparation of anthracite must date back over a hundred years. Two vital factors have determined to a large extent the degree and method of anthracite preparation. These are, first, the character of the beds worked and the methods by which they were mined and, second, the equipment used and practices followed in the burning of the coal. It is not the intention here to go deeply into these phases of preparation as a paper of no mean length could be prepared on the history of either. Rather, the intention here is to point out the main considerations and to show the influence they have exerted on the preparation of anthracite. MINING METHODS AND THEIR RELATION TO PREPARATION In the beginning f the nineteenth century, the coal beds were virgin with the possible exception of some outcroppings that had been worked, to a slight extent, by the Indians. It is known that the American aborigines had a knowledge of the use of this fuel, because when the Wyoming Valley was purchased from them, in 1754, they mentioned the fact that, by selling the land, they would lose their coal.

Jan 9, 1921

By AIME AIME

Award of a Gold Medal : to the Institute. The Jury of Awards of the Jamestown Ter-Centennial Exposition has conferred a gold medal, the highest distinction within its power,. on the American Institute of Mining Engineers for the excellence of its publications during the past decade. ; A half-tone photographic reproduction of both sides of the medal is given in the accompanying illustration.

Jan 7, 1908

Secretary of the Interior, Franklin K. Lane, has appointed a commission of five mining and metallurgical experts from the Bureau of Mines and the Geological Survey to visit Europe to observe and study reconstruction methods in the devastated regions of France and Belgium. The chairman of the commission is Dr. Frederick G. Cottrell, chief metallurgist of the Bureau of Mines. The other members are: George S. Rice, the chief mining engineer of the same bureau; Frank H. Probert, consulting engineer of the bureau, and. professor of mining in the University of California; F. J. Cameron, consulting chemist of the bureau and expert on potash matters; and Hoyt S. Gale, of the Geological Survey, another expert on potash.

Jan 4, 1919

By R. V. Whetsel, Valentin R. Garfias

Mexican petroleum production for 1928 was approximately 50,000,-000 bbl., the lowest in 12 years, showing a decrease from 1927 of over 14,000,000 bbl. The steady downward trend for the past 7 years has allowed Russia to outrank Mexico by a wide margin for third position and if the expected decline continues during 1929 it should place Persia ahead of Mexico as fourth in rank. The year 1928 was characterized by a continuation of the reentrench-ment previously begun by the oil industry in Mexico in an attempt to adjust itself to the adverse conditions caused by the steady depletion of the fields, the rapidly increasing competition from Venezuela and the United States and the as yet unsettled petroleum legislation and taxation situation. With the exception of the Isthmus of Tehuantepee, drilling in proved fields was considerably curtailed and although the number of wildcats completed exceeded those of the previous year, no extensive drilling programs were undertaken. Practically without exception, the major companies reduced personnel and operations to a point where they could meet existing conditions and mark time while awaiting a more stable basis for the future testing of unexploited regions. Many terminal and transportation facilities were abandoned during the year. Development Only 371 wells were completed during 1928, as against 583 in the previous year and 808 during 1926, and although the percentage of producers in 1928 was 34 per cent., compared to 26 per cent. in 1927, the initial production of -wells was considerably lower than during the previous year, a great number of the wells showing salt water and becoming "strippers" from the time they started to flow. Development is summarized in Table 1. Drilling in the Northern fields did not prove any new pools of importance, the most successful wells being located in the old producing areas of Cacalilao, Panuco and Topila. (Fig. 1 Very few of the producers made more than 1000 bbl. daily, and a great many less than 300 bbl. a day.

Jan 1, 1929

By J. Mizrahi, A. M. Baniel, A. Mitzmager, S. Star

This article gives an account of the latest developments in the use of TBE for sink-float separation of silicate minerals. A number of minerals for which the process has been tested and found suitable are reviewed. Specific examples are discussed in relation to the particular problems of sink-float separation and recovery of TBE as compared with non-silicate minerals. The economic aspects are outlined. Silica and silicates comprise the most common and abundant group of minerals, and since they are present in variable amounts in most ores, they constitute an appropriate subject for the review and discussion of the recent developments in the use of TBE for mineral concentration. The silicates considered as a group have an extremely wide range of chemical and physical properties. Some of these properties, which are common to all minerals, are of importance to concentration by TBE and are discussed in some detail in this paper, as well as the development of methods and apparatus for concentration and recovery of TBE and several examples of concentration of silicates. PROPERTIES OF MINERALS WITH RESPECT TO CONCENTRATION BY TBE The properties considered as most important to concentration by TBE are specific gravity, structure, surface and shape. The specific gravity of a mineral is a fundamental property and is constant between very close limits for the same species of different sources if particles are pure and free from cavities or cracks. In many species, however, solid inclusions and changes in chemical composition due to replacement of elements cause variations in the specific gravity. The plagio-clase series of feldspars between albite and anorthite illustrate this point (specific gravity from 2.60 to 2.77). Fig. 1 shows the specific gravity distribution of some of the common silicate minerals.&apos; The highest specific gravity is about 4.7 (zircon) and the lowest is 2.0 (sepiolite), with most of them ranging between 2.6 and 3.5. Although most of the silicates given in Fig. 1 are found as constituents of rocks, those generally considered as rock making minerals are comparatively few. They include quartz, feldspars, nephelite, sodalite, leucite, mica, pyroxenes, amphiboles, chrysolite, kaolin, talc and serpentine. These minerals may appear in igneous rocks as coarse crystals in granites, syenites and diorites or as very fine grained dispersions in basalt and felsite. When the latter rocks occur in an ore, their specific gravities depend on the minerals present and structure. The same is true for the sedimentary and metamorphic rocks (sandstones, shales, gneiss, slate, schists). A comparison of specific gravities for the minerals listed in Fig. 1 with that of TBE (see Table I) shows that the important rock-forming minerals, with the exception of pyroxenes, amphiboles and chrysolite (olivine), lie in the specific gravity range of less than 2.96 and can therefore be separated by TBE. The ore structure is important both in determining the apparent specific gravity and the efficiency of TBE recovery. The structure can be compact (as in

Jan 1, 1963

By William Greenawalt

The Greenawalt electrolytic copper extraction process is applicable to suitable oxide ores, sulfide ores and concentrates, and low-grade matte. The process is self-sustaining in acid on sulfide ores or concentrates, on mixed ores, on high-grade oxidized ores; and on low-grade oxidized ores the amount of acid to be purchased or manufactured is greatly reduced. The ferric iron is under easy control, and copper may be effectively deposited from solutions of any acid or iron content likely to be used in copper leaching. From 60 to 75 per cent. of the copper may be removed from the solution in passing through the electrolytic department, before returning the solution to the ore. The amount of copper requiring chemical precipitation, from the waste and foul solutions, is only about 5.0 per cent, of the total copper produced, and this 5.0 per cent. is converted into the electrolytic metal in the regular operation of the process. The entire process can be made practically automatic, and can be carried out mechanically. There is no uncertain departure of any kind in the application of the process; no unusual or unproved apparatus is used. EVER since electrolytic copper refining gave promise of success, about a half century ago, efforts have been made to apply the idea to the extraction of copper from its ores. The methods of attack have, usually, been to leach with a dilute acid and then to deposit electrolytically the copper from the resulting solution with the simultaneous regeneration of the solvent used in the process. Many efforts have been made, and many patents have been taken out, both in the United States and abroad, to give this idea practical application, but only within the past few years have the difficulties been surmounted. Leaching and electrolysis, as applied to copper ores, are among the most promising fields in modern metallurgy. New conditions are arising, which will bring the wet methods into prominence; while high freight rates and increasing cost of fuel will tend to limit smelting to highly favored localities. The possibilities offered by the installation of hydro-electric plants and the greatly enlarged range of power transmission will greatly widen the field of electrolytic methods.

Jan 1, 1924

By D. S. Jacobus

COMPRESSED-air motors are specially desirable, if economically practicable, for underground haulage, because they require no fuel, involve no danger of fire, and not only avoid heating and fouling the atmosphere with smoke and combastion-gases, but by the emission of expanding fresh air, cool and improve it and aid ventilation. The highest developments in the use of compressed-air motors for locomotion are to be found, in the opinion of the writer, in the principles of the Mekarski car-motor as applied to street tramways, and it is thought that notes taken regarding this system, during a recent trip to Europe, where two plants are in successful operation, at Nantes and Vincennes respectively, will be interesting to mining engineers. The plant at Nantes operates a street-line 5.2 miles long, requiring about twenty motors; the one at Vincennes about 7 miles of road. Each car at Nantes carries its own motor. At Vincennes, however, the motor-car is arranged to tow a second car containing no motor. The road at Nantes is the older, having been in successful operation for ten years, during which time neither the American consul, Mr. Shackelford, who has resided at Nantes for about five years, nor the vice-consul, Mr. Bennett, who has been at Nantes ever since the road started, has ever seen anything go wrong with the motors. DESCRIPTION OF THE RAILROA at Nantes. Motor-Car.—Two small engines are connected&apos; so as to rotate the front axle of the car, a reversing lever being used to alter the cut-

Jan 1, 1891

MONDAY, FEB. 17 9.00 A.M. to 9.00 P.M. Registration at Institute Headquarters. 9.00 A.M. Meeting of Committee on Development of the Activities of the Institute, Room 905, 9th Floor. 10.00 A.M. Simultaneous Sessions of Institute of Metals Division, Room 2, 5th floor. Industrial Organization, Room 1, 5th Floor. 12.30 P.M. Luncheon at Headquarters, 5th Floor. 2.00 P.M. to 4.25 P.M. Simultaneous Sessions of Institute of Metals Division, Room 2, 5th Floor. Industrial Organization, Room 1, 5th Floor. Petroleum and Gas, Room 905, .9th Floor. 2.30 P.M. Sightseeing trip by automobile for the ladies. Among the points visited will be: The American Museum of Natural History. The Episcopal Cathedral of St. John the Devine. The Spanish Museum. The American Geographical Society. The American Numismatic Society. The visits will be followed by Tea. 4.30 P.M. Memorial Service to Dr. Rossiter W. Raymond, Auditorium. 8.30 P.M. Smoker, 5th.floor.

Jan 2, 1919

By Robert L. Akre

When Marco Polo visited China in the 13th century, no one knew what black powder was except the Chinese; they knew enough to make dazzling fireworks with it. But the realization that black powder could also do useful work came much later and, like all important discoveries, it altered the course of history. It was in the 14th century that black powder was first used to break rock in a very crude way; there were no drills and the powder was simply poured into cracks and exploded by setting it afire. Because its energy value was pretty low, the need for something more powerful was felt when the industrial revolution began. In the 1850s, miners began experimenting with liquid nitroglycerine on a limited scale. This was a very sensitive and dangerous explosive. Fortunately in the 1860s, Alfred Nobel succeeded in stabilizing nitroglycerine by absorbing it in kieselguhr-and a new product, dynamite, was born. With it, miners were able to unleash the great energy of nitroglycerine for blasting purposes. But dynamite was still a very sensitive explosive. In subsequent years, other explosives of various strengths and characteristics were developed, such as blasting gelatin, gelatin dynamite, ammonia dynamites, (all containing some nitroglycerine or nitrostarch), and liquid oxygen explosives. These products and their variations supplied the blasting trade for many years. A grained ammonium nitrate product containing some carbonaceous material entered the market in the 1930s. This explosive had below-zero sensitivity-meaning: a No. 6 blasting cap imbedded in it would not detonate it. A more sensitive initiator, called a primer, was needed to detonate this mixture. From Rags to Primacord to Solid-State The first initiator for an explosive charge was probably a rag slowly burning its way to the charge; this method was quite unreliable. Then came the burning fuse, which was an improvement. Next was the nonelectric blasting cap initiated by a fuse. With these initiators, a miner needed quick reflexes and good legs; upon lighting the fuse, he had to run immediately for cover. Development of the electric blasting cap that allowed for accurate timing eliminated this hazard; the electric cap, however, introduced other safety problems because of its susceptibility to extraneous electricity, e.g., ground currents, lightning, and static electricity. These caps also became available in millisecond delays. Development in the mid-1930s of Primacord, a detonating fuse insensitive to electrical currents or impact, further reduced blasting hazards, and is generally acknowledged as the safest known means of initiation. Eventually, Primacord millisecond connectors also became available for delay patterns in blasting. In the mid-1960s, the Primadet delay was introduced; it is a practical nonelectric detonator system that offers the precise timing of electric blasting caps-and is immune to the hazards or effects of extraneous electricity. Recently, Research Energy of Ohio, Inc. introduced a new type of solid-state blasting machine that combines a sequential timer and delay caps. It enables the efficient breakage of rock with a minimum amount of shock, ground vibration, and noise. Improvements in Blast-Hole Drilling World War II created an enormous demand for coal and other minerals in the U.S. and elsewhere. Great efforts and large amounts of capital were spent to find new mineral deposits and develop better mining methods. But while mechanization in mining proceeded at a rapid pace particularly in open-cut work, there was a definite lag in developing new or improved machines for drilling blast holes. The industry continued to depend largely on horizontal, churn, and pneumatic drills. No better machine was available for large scale production. The need for improvement in this phase of mining became more acute in the post-war years. Despite efforts toward further mechanization, mining costs rose rapidly because of mounting inflation and increasingly high wages. In most operations, drilling and blasting the overburden became the principal item of cost. Therefore, whatever size holes were being drilled, the holes had to be spaced so that any foot of the bore hole could be loaded with the maximum load required for the number of cubic yards of material that each foot of the hole was carrying. With the smaller holes that were being drilled, the proportion of drilling cost to the total drilling and shooting cost was much higher than it would have been with larger holes (because of the closer spacing required by smal-

Jan 1, 1977

By M. O. Holowaty, C. M. Squarcy

1750 to 1850: The scene shifts westward across the Alleghenys to the young town of Pittsburgh; charcoal gives way to mineral coal as furnaces grow larger and the blast is heated; above all, Pennsylvania iron is adding strength to the new Nation and building an empire in the West. TWO names are inseparably associated with the Pittsburgh iron industry-those of George Anschutz and John Hayden. The iron ore deposits of southeastern Pennsylvania were found and developed early in the 18th century, and several forges and furnaces were built and operated. It was only after the revolution that the iron men crossed the Susquehanna River, built furnaces in the neighborhood of ore deposits of Franklin County, then along the Juniata River and its valley. Juniata Iron found a ready market in the Pittsburgh area. However, difficulty in transporting it across the Allegheny Mountains induced iron mas¬ters to seek ore and plant locations in the Pittsburgh district. One of the first to reach this area was George Anschutz, who migrated to America in 1789 at the age of 36, reaching Pittsburgh in the fall of 1790. Anschutz immediately set out to organize an iron company in Pittsburgh, and was able to interest some residents in his project. After being informed of an iron ore deposit located only three miles out of town (on the site of the present 26th St. and the Allegheny River) he decided to build there his blast furnace and foundry plant. Total cost of the installation was $300. When the furnace was put in operation, Anschutz, now known as Red George, found that the ore deposit was only an insignificant one and would last no more than a few weeks. A new deposit was found on Roaring Run, in the southeastern corner of Armstrong County. Anschutz transported some of this ore to the mouth of Two Mile Run, where it was loaded on horse wagons and transported to the furnace. In this way, he operated off and on for several months, until the furnace was blown out in 1794. After working for a year as plant manager for John Probst at Langhorntown, he built the Hunting-

Jan 1, 1961