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By Leonard Waldo

PROBABLY some of the views advanced in this paper will appear, from a metallurgical standpoint, little less than revolutionary. It is with considerable hesitancy that I venture to offer a few thoughts concerning what, seems to me to be perhaps the most important development of metallurgy since the introduction of Bessemer steel. Dr. John Percy, with that rare insight which characterizes the epoch-making man, described in a communication to the Royal Society, about 1855, an alloy of duminum and copper which he called aluminum-bronze. The name has "stuck." The term "bronze" has been so variously used that I confess I do not know exactly what constitutes a bronze; but I know that in the great materials of engineering simplicity of composition is a cardinal excellence; and I wish to venture the suggestion that aluminum-bronze is not an alloy of aluminum and copper in any such sense as the compounds of tin and zinc with copper (except the copper-tin compound SnCn3) are alloys. There are several reasons which lead me to this view. In the first place, if a series of bars be prepared containing varying percentages of aluminum and copper, and the electrical conductivity of these bars be carefully determined, a curve of conductivity will be obtained, as shown in Fig. 1, which represents the result of such experiments. While I am not sure, at this time, that the values of conductivity shown in this diagram are wholly dependent upon the percentage of aluminum added, the assumption is a probable one; and the curve indicates that an extremely small percentage of aluminum affects the conductivity in a ratio out of all proportion to the amount of that metal. Another reason is drawn directly from experience in the foundry. If we take from the furnace a crucible containing melted aluminum and one containing melted copper, both at a little more than a red heat, and pour them together, the reaction is so intense that the

Jan 1, 1895

By W. H. Emmons

THIS paper is the third of a series treating of the relations of ores of the metals to igneous rocks. The first1 outlined the general problem; the second2 proposed a classification of lode ores, and showed how the distribution of the deposits is in a certain measure controlled by the contour of the roof of the parent batholith. A number of mining districts were discussed, the examples being selected chiefly from group 2 of the classification. The proposed classification of lode deposits, briefly stated, is as follows: 1. Cryptobatholithic: near hidden batholiths which have not yet been exhumed by erosion. 2. Acrobatholithic: in and near cupolas or domes of batholiths-the high points of larger underlying masses. 3. Epibatholithic: on batholiths, near their rims, but below eroded cupolas, or below the highest points of the roofs. 4. Embatholithic: among closely-spaced outcrops which probably are parts of a single batholith. The outcrops of invaded rocks predominate. 5. Endobatholithic: in and near roof pendants of large batholiths. The invading rocks predominate. 6. Hypobatholithic: in deeply-eroded batholiths, where even roof pendants, have been -eroded. Deposits of certain metals on the roofs of the batholiths are much more numerous in some positions than deposits of other metals, and the horizontal zonal arrangements of lodes of different metals are shown characteristically only in certain groups. In a large measure, also, the character of the fracturing and metallization is determined by, the-position on the roof, of the batholith.

Jan 1, 1927

By Charles M. Rolker

THIS remarkable and well-known district lies about 320 miles south of Salt Lake City, in Washington County, near the Arizona border of the territory. It is now reached by the Utah Southern Railroad and its extension, and the last 100 miles are run by stages. These vehicles are called "jerkies" in the West, which name conveys a good idea of the comfort they afford, and the relief experienced when you alight. Arriving at Silver Reef, the main camp of the district, one sees at once that he stands where once a surging sea had its domain, marked now by heavy sandstone deposits of a red and white color. The town itself, a neat, clean, and orderly mining town, is encircled on the north by traohyte and granite mountains, skirting to the west. They are cut through in places by deep gorges, left us as the only trace of the force of former currents, which drained the adjoining territory to the north; and which when swelled and infuriated by tempests and cloud-bursts, took in their grasp the huge blocks of

Jan 1, 1881

By B. J. Steblay

Roof bolts are the primary means of supplemental support in coal mines and are widely used in other mines. Presently, post installation loads are measured infrequently on only about 10% of the bolts by using standard torque wrenches that limit accuracy to about ± 30%. Because mine roof bolts are long, slender, non-uniformly sized, roughly forged, placed in a difficult environment, and subject to severe bending on installation, researchers have been unable to use ultrasonic reflection techniques to measure strain. A complete measurement system has now been assembled by the US Bureau of Mines, Denver Research Center. Obstacles such as bolt preparation, transducer mounting, reliable reflection, and calibration have been dealt with. The seemingly simple concept of measuring the time of flight of an ultrasonic pulse to a reflector is actually complex due to the need to measure to 0.0025 mm (0.0001 in.) accuracy, the sensitivity of velocity to temperature, and stress, and the stability required to make measurements over several years.

Jan 1, 1986

By C. H. Jr. Herty

THE removal of sulfur from steel has been studied by many investigators, but the quantitative relationships between the factors involved have not been determined. This is undoubtedly due to the number of variables encountered in practice, an attempt to study any one reaction or relation being affected by other reactions the relative importance of which cannot be estimated. The factors that affect the extent of removal of sulfur in the basic open-hearth process are generally considered to be: 1. Basicity of the slag: (a) Iron oxides in the slag; (b) carbon in the metal, or carbide in the slag; (c) temperature. These factors affect the reactions: FeS + CaO = CaS + FeO FeS + CaO + C = CaS + CO + Fe. 2. Amount of sulfur in the gas. 3. Amount of manganese in the metal. The factors which affect the rate of removal of sulfur include, in addition to these 4. Fluidity of the slag: (a) Normal changes in fluidity with temperature; (b) changes in fluidity because of the addition of special reagents such as fluorspar. 5. Agitation of the bath.

Jan 3, 1925

By Gordon H. Chambers

MANGANESE ore is a true jack-of-all trades among industrial minerals, its only possible rival being iron ore. It is used in porcelain enamel, dry batteries, building brick, glazed pottery, floor tile, plastics, welding rods, chemicals, and varnish. You may be reading this through spectacles decolorized with manganese, and the light bulb above you contains some of this element. GEOLOGY Nearly all commercial manganese oxide deposits are of secondary origin; that is, they are concentrated by weathering from other manganese minerals more sparsely distributed in veins. The oxide minerals usually form irregular masses but in some places (Russia) they occur as beds of varying thickness and purity. Some manganese oxide bodies occur in soft gravel or clay formations but in other places the minerals are found in the form of veins and rounded nodules in limestone and other hard rocks. The geologic features of manganese deposits closely resemble those of iron deposits. Classification of the deposits is shown in the following table: I. Classification of manganese deposits based upon form of occurrence A. Stratiform masses 1. Oxides interlayered with sediments or layered volcanic or metamorphic rocks 2. Carbonates or silicates interlayered with sediments or layered volcanic or metamorphic rocks 3. Oxides, as surface bog deposits B. Veins and breccia filling 1. Oxides in larger part 2. Carbonates or silicates partly weathered to oxides C. Irregular masses 1. Oxides 2. Carbonates or silicates largely weathered to oxides D. Aggregates of small oxides in clay or weathered rocks 1. Mainly oxides E. Unclassified deposits II Classification of manganese deposits based upon mode of origin A. Hydrothermal deposits

Jan 1, 1949

By Milton E. Wadsworth, Daniel B. Brimhall

Column leach studies of a low-grade porphyry copper ore were made. The technique used involved alternating oxygen absorption and copper leach cycles. The leach solution was displayed from the column with oxygen. The volume of oxygen reacting with the ore was measured with a gas burette. The copper released as a result of exposure to oxygen was correlated with the oxygen uptake. The oxidation rate was found to be dependent on the pH of the solution wetting the particles and was markedly increased by increasing the temperature of the system. Decreasing the particle size of the sample increased the oxidation rate. A material balance on the system indicated 1 mole of oxygen yielded in excess of 1 mole of copper in solution. A discussion of the important parameters is presented and the results are related to dump leaching in general.

Jan 1, 1974

By R. E. Hook, H. J. Garrett, A. M. Adair

X-ray diffraction and metallographic techniques were employed to examine the impurity phases occurring in as-swaged and recrystallized chromium produced fvom high-purity iodide chromium crystals. Chromium oxides are found to form in a consistent manner associated with the temperature of recrystallization. Microscopically observable second phase particles of Cr203 are observed to form intergranulurly beginning at 1300T. Beginning at 1500°C. Cr30, is formed intergvanulurly, atzd at 1600°C and above Cr30, is also formed in association with migrating grain boundaries. Geometrical traces formed by particles of this high temperature oxide uithin the grains rez)eal the histmy of grain boundary motion. X-ray evidence is presented which suggests the existence of a high temperature form of Cr203. Other impurity phases in addition to the oxides of chromium are also present. THE partitioning Of impurity elements between grain boundary aid lattice sires, either as solutes in solution or as second phases, may exercise an important influence on the mechanical behavior of metals and alloy systems. This partitioning of impurities could have a direct bearing on the iecrys-

Jan 1, 1963

By Norman Brown, Victor V. Damiano

ThE present paper proposes a mechanism of dislocation multiplication at internal inclusions or cavities and presents experimental evidence of such sources in zinc. Using an etching technique recently described by Damiano, Tint, and Herman1 to study the three-dimensional aspects of dislocations in bulk zinc crystals, an investigation was made of helically shaped and closed-loop etch patterns found to be associated with inclusions. Crystals containing 0.1 pet Cd and grown from the melt were deformed slightly by bending and then aged at room temperature to precipitate cadmium at the dislocations. The crystals were cleaved along the (0001) plane and then etched with Gilman's2 etch. Crystals were continuously viewed on the (0001) plane while the etching was in progress and numerous helical and closed-loops etch patterns were continuously recorded as shown in the sequences printed directly from the cine film in Fig. l(a) and (6). These etch patterns are not to be confused with the etch patterns previously reported by Damiano and Herman3 which revealed dissolution spirals on the (0001) plane of high-purity zinc crystals. In the present case, precipitates arranged in the form of closed loops or helicies are progressively uncovered by etching after suitable aging of cadmium doped zinc crystals. Viewed with dark-field illumination as shown in Fig. 2, portions of a helical figure and subboundaries were revealed simultaneously. Continuous viewing while the etching was in progress revealed in Fig. 1(b) that the short line segments observed on single photomicrographs were in fact continuous and described a helix which had its terminus at an inclusion. The observations suggested that a dislocation once nucleated at the interface between the inclusion and matrix may act in such a way as to produce ad-

Jan 1, 1964

By Charles M. Rolker

THIS remarkable and well-known district lies about 320 miles south of Salt Lake City, in Washington County, near the Arizona border of the territory. It is now reached by the Utah Southern Railroad and its extension, and the last 100 miles are run by stages. These vehicles are called "jerkies" in the West, which name conveys a good idea of the comfort they afford, and the relief experienced when you alight. Arriving at Silver Reef, the main amp of the district, one sees at once that he stands where once a surging sen had its domain, marked now by heavy sandstone deposits of a red and white color. The town itself, a neat, clean, and orderly mining town, is encircled on the north by trachyte and granite mountains, skirting to the west. They are cut through in places by deep gorges, left US as the only brace of the force of former currents, which drained the adjoining territory to the north; and which when swelled and infuriated by tempests and cloud-bursts, took in their grasp the huge blocks of

Jan 1, 1881

By Charles Mitke

(San Francisco Meeting, September, 1915) INTRODUCTION THE Copper Queen mine is composed of seven divisions which are operated through the following shafts: Division Shaft Depth, Air Current No. Feet Uncle Sam 600 Downcast (shut clown April, 1914, to 1 curtail production) Southwest 600 Downcast 2 Czar 400 Downcast 3 Holbrook 600 Downcast 4 Spray S00 Downcast (shut clown April, 1914, to curtail production) 5 Gardner 1,000 Downcast 6 1 Dallas 1,400 Downcast 1 Lowell 1,600 Upcast 7 Sacramento 1,700 Downcast " I I The workings of the different shafts are connected by motor-haulage drifts on the even numbered levels. The general location of the orebodies and workings is illustrated by the vertical projection of orebodies of the district as shown in Fig. 1. The Uncle Sam, Southwest, and Czar workings have many connections to the surface through raises and extensive cracks that were caused by moving ground. These divisions are cool and are ventilated entirely by natural means. The Holbrook is ventilated partly by natural and partly by artificial ventilation, while the Spray, Gardner, Lowell; and Sacramento are ventilated entirely by mechanical means. In some of the divisions mentioned above a considerable quantity of air exhausts through shafts of adjoining properties.

Jan 9, 1915

By C. M. Loeb, A. M. Gaudin, J. H. Brown

THE object of most size reduction operations in the mineral industry is to liberate the grains of valuable minerals in the ore from those of the gangue. This is usually accomplished by crushing and grinding the entire mass of ore until there is only a small probability that any single particle contains more than one mineral. During this size reduction only limited control exists over size or composition of the particles exposed to the breaking action, and there is no control over the paths followed by cracks generated during the operation. This lack of control usually results in overgrinding and in production of large quantities of very fine material. The first detriment, overgrinding, is costly in itself, but when combined with the second factor it is doubly so. Not only is the fracture of a free particle unnecessary-the fracture of these particles may also make subsequent separation operations difficult, inefficient, and wasteful. It has been pointed out' that if the object of size reduction is to liberate the valuable mineral component of the ore then, ideally, fracture should follow intergranular paths to the exclusion of trans- granular ones. This would result in liberation of the valuable minerals with as little size reduction as possible. This ideal comminution operation is referred to as intergranular comminution, and it was the object of the investigation to determine the extent to which it could be developed by heat treatments.

Jan 4, 1958

By George M. Fowler, R. E. Illidge

Part I. Developing BY GEORGE M. FOWL INTRODUCTION The Tri-State district comprises an area of about 2000 square miles in southwestern Missouri, southeastern Kansas, and north [ ] eastern Oklahoma. The part that is in and contiguous to Missouri is still sometimes designated as the Joplin district (Fig. I). EARLY OPERATIONS Mining operations in what is now the Tri-State district date from about 1848 and have been continuous to the present. Apparently the first discoveries of ore were made about the same time near the present sites of Joplin, Oronogo, and Granby. Lead minerals were found at grass roots, probably in shattered rock in shallow excavations, then these minerals were followed in shear zones to deeper horizons. The mining of zinc followed. Before 1874, zinc ore was worthless and discarded as waste. According to published records, the total production of lead to that date was 49,000 tons of metal from 70,000 tons of concentrates. PRODUCTION The aggregate ore production from the Tri-State district was recorded at interval

Jan 1, 1943

By J. M. Bugbee

THE engineer and the conservationist agree that effective water drive is the desirable reservoir production mechanism. Water drive may result either from the expansion of edge water, the reservoir water bordering an oil pool, or from the artesian flow of edge water from the outcrop. Thus, the extent of the reservoir has an important bearing upon both the rate and the ultimate quantity of water influx to an oil pool. Lens-type reservoirs are generally recognizable, but the complete structure of the more important domal types, having possible limitations from crestal and synclinal faulting, is not well understood. The delineation from cores, electrical logs and exploitation phenomena of the crestal portions of reservoirs is increasingly exact. This paper suggests that inference from these factual pictures, combined with the scattered well and geophysical data of the synclines and with consideration of the dynamics of structural formation, may be applied to solving the complete geologic structure. Since faulting on the domes and in the synclines may effectively seal and thus limit the size of a reservoir and bar additional water influx, consideration of geologic structure and its possible effects is essential to complete analysis and prediction of reservoir performance.

Jan 1, 1942

By John Fulton

The following table shows the shipments from the four Lake Superior iron-ore districts during the year 1887, and their total outputs from their beginning until the close of 1887.* It will be noted that the Menominee district is second in importance in its total output tonnage to the close of the year 1887. These ore deposits are found in jasper-slates and in the horizon between these and their associated clay-slates; in the latter they are true contact-deposits. They are found in this jasper- and clay-slate formation under varied conditions, yet, in all, certain characteristic laws are preserved. The angle of dip varies from 15° to 20°, and up to 85° and even 90°, with the horizon. The ore is rather soft, bluish-black in color, and is a hematite. It varies in thickness from a few inches to one hundred feet, or more. It is mainly "Bessemer" ore, containing 57 to 63 per cent, of metallic iron, and .03 to .07 per cent, of phosphorus. In the mining nomenclature of this range two conditions of the ore-lens are described by the terms "dip" and "pitch." The former is in common use in defining the relation of the ore-plane to the horizon ; the latter indicates the posture of the ore-body as it inclines east or west from its position at the opening of the mine. In the

Jan 1, 1888

By Charles W. Goodale

The attention of the Institute has been called by Prof. John A. Church* and Mr. W. Lawrence Austin? to the free-milling ores of the Tombstone mines and their treatment, but the silver-bearing man ganese ores of the district have received only a passing notice. As these ores show some interesting peculiarities, and have yielded not less than 750,000 ounces of silver, they are worthy of some study. The Knoxville, Lucky Cuss, Luck Sure, and Wedge mines (named in the order of their importance) are situated along the northern border of the district. They have been the leading producers of this manganese ore, and possess the same general characteristics. Special attention will be given to the Knoxville, as it has been the one most extensively developed. The limestone belt, in which the Knoxville ore bodies occur, has an easterly and westerly trend, is about 1680 feet wide, and rests on granite on the north, the plane of contact being nearly vertical. It is overlain by quartzite, the contact-plane having a dip of 82°. Some mining has been done along these contacts, and a considerable amount of pay ore has been extracted, but development has been very superficial. The ore found along these contact planes contains very little manganese, and differs entirely from the ore in the lime stones. No attempt will he made to assign this limestone country-rock to a particular geological horizon, as no fossils have been found in it. Prof. Blake, in a paper on "The Geology and Veins of Tombstone, Arizona" (Trans., x., 334), speaks of the middle and upper strati-

Jan 1, 1889

By William G. Brissenden

Gaspe Copper Mines Ltd., a subsidiary of Noranda Mines Ltd., operates a completely integrated copper mining, milling and smelting plant at Murdochville, on the Gaspe Peninsula of Quebec. Operating six days a week, the mine produces 8000 tpd of ore. The mill runs continuously and capacity is rated at 6500 tpd of ore. Treating Gaspe concentrate output plus a certain amount of custom concentrate, the smelter produces between 3700 and 4000 tons of copper anodes per month.

Jan 9, 1959

By J. J. Bailey, R. C. Dean

Dr. Maurer has reviewed the large and confused field of rock mechanics and drilling. We have focused our attention on advance drilling and the disengagement of rock. To understand drilling in greater detail is certainly desirable, but such understanding does not necessarily hold any certain promise of near-term practical advancement. In the longer term, it is probably essential. Present work on drilling and our understanding of drilling falls roughly into three separate classes (and, indeed, these are in no way peculiar to drilling): 1) we have knowledge of certain (scientific) topics which seem to be relevant to the process, 2) we have knowledge of the drilling process in both qualitative and quantitative terms from observation of the actual process, and 3) we have certain modeling procedures, by which we bridge the gap between these two previous areas. The usefulness of our scientific knowledge depends critically upon this last item. In all our following remarks we shall consider only those problems of drilling and the disengagement of rock in which the rock behavior is essentially brittle. Let us start by examining some of the problems of constructing an even moderately detailed theoretical model of the drilling process in the small. The prospects of any near-term success in that direction seem extremely meagre; nor is it clear that any great advancement in the practical art of drilling is even likely to result from the construction of such a detailed model. On the other hand, as we shall suggest later, considera-

Jan 1, 1967

By W. C. Hittinger, J. McGlassan, J. W. Peterson

THIS paper describes the result of an investigation of the production of thin alloyed layers on a thicker substrate of pure germanium as one step in the manufacture of transistors.' The technique of alloying materials with semiconductors is a means of introducing small amounts of impurity elements in the alloyed regions of the crystal lattice of the semiconductor, the presence of which make possible the junction type transistor.2 Impurity elements are added which will produce regions having differing electrical resistivities and means of carrying current. Impurities are of two types: those which produce an excess of electrons (negative or n-type), and those which produce a deficiency of electrons (positive or p-type) in comparison to the pure semiconductor. The boundary between two such regions is designated a p-n junction. Elements in Group V of the periodic table, having five valence electrons, give rise to an excess of electrons when present substitutionally in the semiconductor lattice (usually germanium or silicon from Group IV). Similarly, elements in Group III create a deficiency of electrons. Germanium and silicon which are substantially free of impurities of either p or n-type are designated intrinsic (i-type) semiconductors. The usual junction ----trarnsistor has

Jan 1, 1958

By H. K. Martin

IN September 1954 the Lavender pit concentrator at Lowell, Ariz., began treating low grade porphyry copper ore from the nearby Lavender mine. Nominal capacity of the mill is 12,000 tpd, but production now averages 16,226 tpd. Plant design was somewhat affected by the re-use of old equipment and the substantial re-use of old buildings. A breaking-in period between June 24 and Sept. 1, 1954, was devoted to training operators and making minor changes in launders, chutes, and piping. From Sept. 1, 1954, to July 1, 1956, the mill treated 8,598,105 dry tons of ore, from which 556,541 tons of concentrate were produced, containing an indicated 144,055,185 lb of copper.

Jan 11, 1957