Search Documents

By Paul Billingsley

The term Boulder batholith was first applied in 1897 by W. H. Weed2 to the extensive mass of granite in western Montana within whose borders occur the ore deposits of Butte. In a general way this was known to extend from Helena on the north to the Highland Mountains near Butte on the south, and to be relatively narrow in its east-west diameter. Its intrusive relations to the surrounding sedimentary rocks, and its probable Tertiary age, were described by Weed, but in many ways his statements, based upon incomplete data, have required revision. Most notable of the errors of this description of the batholith were the failure,3 since corrected, to recognize the intrusive contact of the granite with the capping of andesite, and the complete absence of any reference to the many extensions of the granite beyond the somewhat narrow limits of its largest exposure.

Jan 1, 1915

By F. E. Bedale

STUDY of several severe mine explosions that occurred during the winter of 1907 led to the belief that coal dust was a definite explosion hazard. The Consolidation Coal Co. was a pioneer in the early work to' eliminate this hazard and to combat the dangers incident to poor ventilation and the presence of methane. Maintenance of high humidity throughout the mines was one of the first measures adopted, later to be superseded by rock-dusting. In the twenty years from 1907 on, many safety measures were developed and adopted, and several prizes were won, though the practice was crude by present-day standards. But in 1927, the company went to work in earnest, and organized a Department of Safety with adequate personnel and with authority to enforce all approved rules for the prevention of accidents and the preservation of company property. All plans for new construction work, changes in mining systems, and proposals for the purchase of new mining equipment had to receive the approval of this Department. A set of operating- and safety standards was written to govern the activities of all employees, and physical examinations for them were required.

Jan 1, 1938

By Elmer W. Pehrson

NINETEEN FORTY-SIX was an eventful year for the mineral industries. Perhaps the most significant development was the socialization of industry in Great Britain, initiated in 1945 but carried to fruition in the coal industry in 1946. On Jan. 1, 1947, management of the coal industry will be vested in a National Coal Board, responsible to the Ministry of Fuel and Power. A sum of £164,660,000 has been provided to compensate private owners for assets transferred to the Board. The British coal industry has been a problem for many years. Production has declined to a point where serious shortages of fuel for domestic needs have developed. Exports have dwindled to a small fraction of the previous trade. Costs have increased greatly, and quality has deteriorated. The industry's physical plant has not kept pace with the rapidly mounting wage scales in recent years. Some claim that the best and most accessible coal reserves of Britain are heavily depleted. The industry has been harassed by difficult labor problems, including bad morale among the workers and a shrinking labor force.

Jan 1, 1947

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 W. T. Isbell

Although the pressure to meet the heavy demand for lead still took precedence over new metallurgical developments in the field of roasting, smelting, and refining of lead in 1948 there nevertheless has been considerable activity in the experimental development of new processes and improvements as well as plans for the modernization of many plants both here and abroad. Increasing labor and material costs have stimulated the trend to greater mechanization, revamping of flow sheets, and construction of larger units wherever possible. Although there have been many serious labor stoppages in the United States, Mexico, and Europe, labor supply has improved in most plants even if it has fallen off in efficiency.

Jan 1, 1949

By M. L. Fuller

DURING the last several years many papers have appeared dealing with the structure of highly polished metal surfaces. The awakening of interest in this subject is due to the applicability of the electron diffrac-tion technique to the study of surfaces. The original theory of Beilby1 considered the surface of polished metals as of the nature of a super-cooled liquid or a vitreous, amorphous solid. The electron diffraction effects from polished metals have been interpreted by many to be a direct experimental proof of the correctness of the Beilby theory. This inter-pretation has been strongly opposed by others, so that at the present time the subject is in an uncertain and controversial state. In the present paper new, and hitherto unpublished, electron diffrac-tion effects from polished zinc are described. These observations indicate that the polished surface of zinc is crystalline.

Jan 1, 1938

By Edward Keller

Jan 1, 1906

By Stanford O. Grodd

The Sanford Lake district encompasses an area covering 24 square miles in the central Adirondack Mountains of northern New York State. Discovery of the titaniferous magnetite deposits dates back to 1826. Several attempts to exploit the ores for iron prior to 1942 proved uneconomical because of difficulties with the associated titanium, lack of transportation facilities, and the isolated location. Since 1942, the National Lead Company has produced ilmenite concentrates for the titanium pigment industry, and a magnetite by-product used in the steel and refractory industries. Rocks of the area are Precambrian in age and of igneous origin. The area has a history of erosion, deformation, and metamorphism, subsidence, and finally uplift and glaciation. The resulting topography is extremely rough with drainage patterns controlled by a combination of fault patterns and glacial modifications. The district is within the large anorthosite massif making up the central high peak area of the Adirondacks. All of the various lowsilica rock types associated with the massif are found within the boundaries of the district. These consist of both the Marcy and Whiteface types of anorthosite and of gabbroic anorthosite, gabbro, and different grades of titaniferous magnetite ores. All of the rocks contain the same minerals and differ only in their percentages of these consitituents. Gabbro, and ore associated with it, demonstrate flow structure as both have foliation and lineation. Anorthosite and its associated ores are massive and show very little primary structure. Minor pegmatites and diabase dikes provide evidence of remobilization in selected areas and of late intrusion as well. Faulting is prevalent and follows a regional pattern of major faults trending northeastsouthwest and of minor faults at nearly right angles to them. There are four mineralized areas where an economic grade of ore has been found. Three of these have both gabbroic-type ore and anorthositic-type ore. The fourth has only gabbroic ore. Ores are graded according to their TiO, content, and these range from 9.5 per cent to over 30.0 per cent TiO,. Ore bodies of both types are related to gabbro and conform to the configuration of the gabbro bodies within the anorthosite. At least three distinct theories of ore genesis have been expounded by different investigators. Others propose some variations of one or more of these. Although complete agreement probably never will be reached, it is certain that no one process of ore emplacement can explain the complicated picture as seen today. Further understanding of the ores and their origin will require detailed mapping, sampling, and mineralogical studies of the entire district, and then it may never be understood without qualification.

Jan 1, 1968

By Robert F. Mehl

EXTENSION of physical and chemical methods of research in the study of metallic behavior continues rapidly, particularly in the correlation of behavior with crystal structure, and in the analysis of elastic and plastic properties. The growth of the science of metals during 1933 calls for special comment; the need for special reviews and for textbooks and monographs is now acute, as might he supposed from the number of references appended to this article, a list which is much abbreviated.

Jan 1, 1934

TITANIUM is one of the most abundant elements in the minerals that make up the earth&apos;s crust but its use in industry is only a generation old; yet probably no other important commercial mineral raw material (except possibly magnesium) has undergone more changes and developments in sources of supply, in processing techniques, in uses and applications, in the past 10 years, or stands on&apos; such a threshold of still more advances. Its outstanding use today is as the oxide, and because of its extreme whiteness, high refractive index, chemical stability, and relative cheapness, it has become the white pigment used in the largest volume. New developments in the uses of titanium metal, potential and actual, may surpass the pigment use of the oxide before many years. TITANIUM-BEARING MINERALS Although a number of minerals contain titanium as the principal metal, only a few are of commercial importance. These are arizonite, ilmenite, and rutile. The other oxides, brookite, pseudobrookite, and anatase, occur in a few deposits, one at least of minor importance. The silicate titanite, and the double oxide of calcium and titanium, perovskite, occur in a few deposits in quantities sufficient to be considered as potential ores were not richer deposits of the oxides available elsewhere. Arizonite is a name given by Palmer46a to a mineral found some years ago in minute quantities in Arizona, which has the formula Fe203.3Ti02. Unexpectedly, it was found that the black titaniferous iron oxide found in large quantities on the beaches of many continental land masses corresponds in chemical composition to this formula (although ferrous oxide is always present). No one has yet been able to prove that the commercial mineral on the beaches is truly arizonite, or an allotropic modification of it, since X-ray investigations by Howard Carl and A. F. Gabriel, of the U. S. Bureau of Mines, and by the X-ray laboratory of the Chemical Department at the Experimental Station of the du Pont company, have shown only that the sand mineral gives just a jumble of lines, rather than an identifiable pattern. Lack of a better name,

Jan 1, 1949

By E. N. Harshman

Uranium mining and milling are rather new industries in Wyoming and South Dakota, but, in the past 15 years, ore valued at more than $400,000,000 has been mined and milled in the region. The major uranium deposits are in structural and/ or erosional basins or on the flanks of uplifts. The principal host rocks are medium- to coarse-grained sandstones that were deposited in continental or brackish-water environments and were derived in large part from the granitic cores of the uplifts and the sedimentary rocks that flank the cores. The ages of the host rocks range from Cretaceous to Miocene, but more than 95 per cent of the known reserves in the region are in rocks of early Eocene age. The bulk of the ore in the region is unoxidized and lies below the water table; some oxidized ore has been mined in the Powder River Basin and Black Hills districts. The unoxidized ore comprises pyrite, uraninite and/ or coffinite, marcasite, hematite, jordisite(?), and selenium. Minerals in the oxidized ore include hydrous uranium carbonates, phosphates, and sulfates and hydrous uranium and/ or vanadium silicates. The deposits are in the form of ore rolls that contain from a few hundred to a few hundred thousand tons of ore, ranging in grade from 0.1 per cent to 1.0 per cent U3O8. The rolls are at the margins of large tabular bodies of sandstone that has been altered by the orebearing solutions. The deposits are believed to have resulted from the interaction of an alkaline; oxidizing, ore-bearing ground water and a reducing environment. Exploration guides include the spatial relations of ore to altered sandstone, favorable lithology in the host rock, the content of certain elements and/ or compounds in ground water, and the relation of deposits to major paleodrainages.

Jan 1, 1968

By O. T. Berge

Development and production from open cut mines continued its vigorous growth trend during the year 1968. Material handling and transportation were again exposed to the use of larger equipment with shovels, trucks and front end loaders leading the way. Highlights of World Mining Activities Africa: The Anglo American Corp. opened a new high-grade copper mine in Zambia during the year. In Angola, the Companhia Minera do Lobita planned a 3 million ton iron ore production for 1968 from new mines which will ultimately produce 5 million tons per year. A feasibility study of Bethlehem Steel Co., for the development of large high- grade iron ore reserves in Gabon, was in final stages of completion this year and Pickands Mather and Co. continued its investigation of iron ore deposits along the Ivory Coast.

Jan 2, 1969

By G. A. Beiswenger

The application of the law of supply and demand to the sale of crude oil is generally conceded, but the motives underlying the buyer&apos;s (refiner&apos;s) demands are not always obvious to the seller (producer). In some cases this obscurity has led to the conclusion that the refiner may be unnecessarily particular when he selects one crude and rejects another. This preference, however, is very largely the reflection of the refiner&apos;s product demands and the quality of the stocks obtainable from the selected crude. The purpose of this paper is to point out critical characteristies of the major classes of refined products and to show how crudes vary in their suitability for such products. With relatively few exceptions, available processing methods and addition agents make it theoretically possible to produce any type of refined product from any crude source, although it may not be economically sound to do so. The widespread application of thermal cracking for converting higher boiling stocks into gasoline is well known. More recently cracking and refining in the presence of catalysts9 have been developed, as well as various processes for polymerizing lighter hydrocarbons into gasolines having desirable characteristics.6 For several years, selective solvents have been applied commercially to refining inferior quality kerosene, Diesel fuel and lubricating oil distillates.3 Improved methods for refining lubricating oils from crude residual4 formerly suitable only for fuel, are now in use and a number of special solvent processes are available for dewaxing lubricating oils to low pour point.5 These improved refining methods have been developed not only to meet the demand for improved product quality but also to enable the refiner to obtain quality products from crude sources that would not yield such products by the older refining methods. In many cases, the utilization of these modern refining tools necessitates an appreciable expenditure for equipment as well as added manufacturing costs, and their application therefore must be justified economically. Despite the availability of such tools, the added processing costs involved and yields obtainable may render their application entirely impractical. To illustrate this point, inspections of typical cuts from various crudes

Jan 1, 1940

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 G. A. Vissac

MOISTURE in coal must be considered as an impurity, just the same as ash, from the standpoint of utilization of the coal. Being incombustible, it reduces directly the heating value of the coal, and in addition absorbs heat for its evaporation. Its presence means useless expenditures in handling and transportation. In coke plants, extra moisture reduces capacity and may cause damage to brick work and equipment. Accordingly, the removal of extra moisture can be considered just as important as the removal of other impurities, such as ashes, in the modern coal preparation plant. Moisture, which can be removed by heating the coal up to a temperature of 100°C, may be retained in various forms: 1. As a film, on the surface of each coal particle, and in the interstices between particles, retained by capillary forces. 2. Or "occluded" inside the coal particles. This occluded moisture may be either free moisture (as in a sponge), or hygroscopic moisture which varies with atmospheric conditions, (also called "regain").

Jan 1, 1949

By J. F. Myers

A bit of old philosophy: The optimist, the pessimist, The difference is droll; The optimist, the doughnut sees, The pessimist, the hole. This is a neat summation of the viewpoint of those engaged in "treating the crude mineral crust of the earth." Many of those in high places have reminded us during the year of the diminishing supply of the resources so essen-

Jan 1, 1948

(There are 82 Local Sections in the United States, 10 Foreign) ADIRONDACK Established June 18, 1952 Official year begins in January Meets next to last Saturday monthly April through October Local Section Dues AIME Mbrs $2 Affiliate Mbrs $3 Severn P Brown, Chairman George E Erdman, Vice-Chairman Patrick F Farrell, Secretary-Treasurer Republic Steel Corp Mineville, N Y

Jan 1, 1960

By W. P. Barba

IN THE early summer of 1917, it became evident that the then existing sources of supply of guns and gun forgings were totally inadequate for the enormous and rapidly growing requirements of the Ordnance Department of the Army, so arrangements were made with sixteen makers of other products to take up the manufacture of guns and gun forgings. Nine of these makers were required to produce their own steel from the raw materials and convert it into rough machined gun forgings; the others finished and assembled these forgings into completed guns. In December, 1914, four of these makers of steel and rough gun forgings were instructed to manufacture the same amount of the 6-in. and 9.5-in. guns and howitzers. It, therefore, seemed practical .and profitable to assemble these makers into a small group, together with the officers of the Ordnance Department, and provide standard &apos;equipment in each of the four works for the production of these two types of guns. The advantages of this cooperation were immediately manifested, and there commenced an interchange of shop practice and a free discussion of facilities and methods that covered not only the equipment but the manufacturing processes.

Jan 1, 1920

Body Hoists A complete new line of hydraulic dump truck body hoists and bodies featuring many outstanding design improvements has just been announced by St Paul Hydraulic Hoist Fourteen models of this new hoist are available in a selection of capacities from 6 to 25 tons The new body hoist features low standard mounting height, advanced lifting point, new low operating oil pres [ ] sures, a new Uniflex subframe, friction-free roller bearing drive mechanism, including pump and power takeoff, to insure quiet operation and long trouble-free life A stress-eliminating design feature of the new hoists absorbs dumping shocks and permits use of a new principle in hoist design a flexible subframe which ends tendency of rigid hoists to crack or bend when flexed Circle No. 1 Combination Drill A new combination drill offering all three methods rotary, auger, and percussion drilling on the same rig is the revolutionary feature of the latest drill rig designed by Mobile Drilling Inc The B-36 drill is larger, more powerful and versatile than previous models built by this company This new drill has a hydraulic feed of approximately 8000 lb pressure The hydraulic feed cylinder is located directly over the rotary turn table The carriage of the drill is of tubular construction The drill mast, also of tubular construction, nests in the tube members of the drill carriage for cross-country travel with a maximum overall height of 10 ft The drill mast telescopes together with the feed cylinder hydraulically to an operating height of 16 ft The drill can be furnished with an auxiliary cat head, sand reel, and special high pressure water pump The B-36 maximum depth for auger drilling without water is approximately 150 ft, depth for rotary drilling with water is in excess of 300 ft Circle No 2

Jan 1, 1952

By Gordon MacVean

THE adoption of rock dusting, as a safety measure, has made notable progress in the West Virginia coal mines since May, 1925. At that time there were but two mines in the State that were thoroughly rock dusted, mines No. 2 and No. 12 of the Boone County Coal Corp., at Sharpless. Since then it is probable that 75 per cent of the coal operators in the State have given consideration at one time or another to rock dusting. This growth of interest followed the meetings of the various mining institutes all over the country, during the summer of 1925, at which papers were presented, drawing the attention of the coal mining operators to the merits of this safety measure. Yet outside of the experience with rock dusting at the Old Ben Coal Corp., of Southern Illinois, and the Carbon Fuel Co., of Rains, Utah, there had been no actual occurrence in the coal mines of the United States, which could be taken as positive evidence of the efficacy of rock dusting in the prevention of the propagation of coal dust explosions. The U. S. Bureau of Mines, however, had run innumerable tests under conditions which closely approximated actual coal mining conditions and had clearly shown that rock dusting was effective.

Jan 1, 1926