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By Fred Chappell

Pyrophyllite, a hydrous aluminum silicate, physically similar to talc, receives its name from the Greek word Pyr, for fire and phyllite, a rock or stone. Firestone refers to its first recorded use as firestones or hearthstones. Composition and Properties Pyrophyllite is an aluminum silicate A12O34SiO2H2O (alumina 28.3 pct, silica 66.7 [ ] pct, water 5.0 pct) (Table 1). Vanderbilt1 gives pH value of pyrophyllite as 5.6 to 8.4. Pyrophyllite is usually white or cream, though it may be found in shades of pale green, pale yellow, buff or light gray, and in darker shades and other colors principally due to oxidation of contained iron minerals. It is opaque to translucent in thin sections. Its hardness is 1 to 2 in the Mohs scale. Its specific gravity is 2.8 to 2.9. Its luster is pearly to dull; it is recognized chiefly by its micaceous structure and cleavage, and its soft greasy feel. Two other varieties occur, one in which there are radiated needles in the crystalline form, and there is also a massive homogeneous structure found. Fine grinding reduces pyrophyllite to fiat plates or scales but aggregates of minute foliated plates may be formed.1 Distribution of Deposits Pyrophyllite is found in metamorphic rocks throughout the world but it is only in comparatively recent years that it has assumed much commercial importance. The principal

Jan 1, 1960

By Eugene C. Robertson

INTRODUCTION A direct proportionality between the observed displacement of a fault and its thickness of breccia and gouge has been proposed recently (Robertson, in press). To validate this finding, an explanation of the mechanics of continuous breccia formation is needed and is offered in this paper. A summary of evidence for the finding will show why an explanation is needed. The correlation between fault displacement [d] and accompanying breccia- plus-gouge thickness [t] seems to be linear and reasonably well established over 6 orders of magnitude, with a range in [d] from 1 mm to 1 km, on a trend of [d/t]= 100, shown in Figure 1. Most of the points are for faults observed underground in mines. The [d] – [t] relation is limited to normal and reverse faults, that have a flat to steep dip and a displacement less than 5 km. It is not applied to large strike-slip and low-angle overthrust faults, whose displacements and breccia thicknesses are widely variable and uncertain. Undisplaced jointed rock is not included in the thickness measurement. A complete description of sources and analysis of the data is given in Robertson (in press). One would intuitively expect that continued movement on a fault would grind up the previously formed breccia and gouge and not produce any more, but the evidence (Fig. 1) indicates otherwise. A physical model to explain continuous formation of gouge and breccia from the wall rocks can be obtained from laboratory experiments on friction.

Jan 1, 1982

By H. R. Gardner

THE wide variation in tension and compression properties' which exist between the a,ß and ? phases of plutonium indicate that a study of the impact properties would give a greater insight into the variables affecting the mechanical properties and formability of plutonium. In tension the a phase is quite brittle with elongations less than 1 pct. The ß phase at normal test speeds is unusually ductile; elongations up to 621 pct have been obtained. However, the ß phase is quite sensitive to strain rate; elongations decrease rapidly as strain rate is increased. The y and 6 phases are less ductile than the ß phase, with the 5 phase the more ductile of the two. Neither are very sensitive to strain rate. Considering the brittle nature of a Pu in tension and compression and the strain rate sensitivity of ß -phase Pu, both unnotched Charpy specimens and standard V-notched Charpy specimens were fabricated for testing. In addition, since iron in amounts greater than 500 ppm forms a Pu-PlgFe eutectic network which inhibits microcracking in as-cast plutonium,' it was decided to prepare impact specimens with low and high iron contents. Chemical analysis and density data for the impact specimens are presented in Table I. A total of 55 impact specimens, 32 unnotched and 23 with the standard Charpy V-notch were tested at temperatures from —45' to 330°C. The test results for both unnotched and notched specimens are illustrated in Fig. 1.

Jan 1, 1962

By Edward Perry

IN the exploration of a copper deposit by drilling, obvious advantages are to be gained from a distinction between primary and secondary ore.1 Perhaps the chief of these is the aid which such a distinction renders in determining where a given hole should stop. The copper assay, often a sufficient guide, cannot always be exclusively relied upon. Primary ores may extend downward indefinitely and may fluctuate in value independently of depth: if primary ores are consistently lean for a considerable vertical distance, there is little reason to expect that, still deeper, they will increase to the commercial grade; on the other hand, rich primary ores may persist uninterruptedly downward or may come in again below a lean interval. Secondary ores, however, have a comparatively limited vertical extent; in a large way enrichment decreases with depth and finally gives out. It follows then, that when a hole descends from profitable ore into ore of less than the commercial minimum, the practical significance of the situation depends upon whether this decrease results from a decrease in secondary enrichment or is a variation in primary content: if the copper of the ore passed through has been chiefly secondary, little is gained in the average case by extending the hole much below the point at which the commercial limit is reached; but, when copper is chiefly primary, due weight must be given to the possibility that, still deeper, the ore may again improve.

Jan 2, 1916

By J. P. Manning

UNQUESTIONABLY, the outstanding feature of the piping for the sulphide plant is the large amount which had to be done in almost every size from instrument tubing to 84 in. OD pipe. In this article the piping will be considered under the main headings of Yard Piping and Building Piping. Tables I and II give data concerning the individual systems. In the case of yard piping the figures pertaining to lengths and weights are approximately correct; those for building piping are given only for the concentrator and smelter buildings where the amounts were the most extensive. Yard Piping The installation specifications for yard piping called for all sizes larger than 12 in. to have welded joints made with outside welding rings. This type of joint was selected over butt-welded joints because less time would be needed for lining up, damaged pipe ends would be less of a problem, and deflections up to 6° per joint could be made when necessary. These advantages were thought to outweigh the disadvantage of the greater amount of welding required. Yard piping in sizes of 3 to 12 in. was specified to have butt-welded joints made with inside welding rings which were intended to facilitate lining up and keep welding material out of the lines. Screwed connections were specified for sizes under 3 in. No protective coatings or wrappings were required on pipe to be buried because of the dry climate at Chuquicamata.

Jan 1, 1952

By E. E. Russell Tratman

The use of dynamite in cold weather is attended with some difficulty, owing to the freezing of the material and its consequeut liability to fail to explode when the fuse is fired. With proper methods and care the dynamite can be thawed with reasonable safety, but numerous accidents occur (more than get reported in the public press), due to carelessness in the operation and to the treacherous nature of the material, or a combination of both conditions. Dynamite will stand treatment at one time which at another time will result in explosion. An expert on explosives says that the most dangerous means of thawing cartridges are ingeniously devised by ignorant laborers; baking, boiling and toasting being favorite methods, while at a stone-quarry, in one instance, an apparatus was arranged for steaming the cartridges over a pot of boiling water. In this latter case the nitro-glycerine leaked through the canvas cover and settled on the bottom of the pot, with the result that an explosion occurred, the water acting as a tamping to the charge. The fact that small quantities of explosives containing nitroglycerine will burn quietly and without explosion if ignited by direct contact with a flame, has led to the dangerously mistaken reasoning that merely heating the explosive can produce no ill effect. If . a dynamite cartridge is ignited or placed in a fire it will probably burn harmlessly away, but if placed on a stove or in an oven and

Jan 1, 1893

By Douglass D. Donald

The New Jersey Zinc Co. successfully holed through a 2 ½ -mile haulage tunnel connecting its new Ivanhoe shaft with the Van Mater Shaft at Austinville, Va. This 8 x 10-ft cross-section tunnel was driven from both ends and met at a point approximately a mile from one shaft and a mile and a half from the other. In order to make certain that the faces met accurately on line and grade it was necessary to refine conventional mine surveying practices. The mines that are serviced by these shafts are located in the southwestern part of Virginia approximately midway between Roanoke and Bristol at the west foot of the Blue Ridge. While the presence of lead-zinc sulfide ores has been known in this area for more than 200 years, it was in 1902 that New Jersey Zinc Co. acquired the Austinville property, which has been in constant operation since that time. About ten years ago the company undertook an extensive diamond drilling program at Ivanhoe several miles to the southwest. This program was successful in locating sufficient ore to justify the purchase of a number of the properties in this area and plans were made to develop the new orebodies. The discovery of this ore as well as substantial additional reserves at Austinville resulted in a decision by the company to increase its daily milling capacity to 3000 tons, of which about 1000 tons would be supplied from the Ivanhoe mine.

Jan 9, 1958

Henry C. Carlisle: This is a husband-and-wife act, in which Mary Carlisle is going to listen, and break in as often as she feels like it. I am going to describe my career as a mining engineer. We are at Nantucket, in the 75 Main St. house; The year is 1959. Q: This is something the boys and I have wanted you to do for a long time. Carlisle: After leaving Columbia in 1910, I arrived at Ray, Ariz., January 1, 1911, and rustled a job from Louis Cates, Ralph Nowland and Sprott Boyd, who were running the Ray mine. I went to work as a surveyor's helper, made $90 a month, and paid $35 a month board. I lived in a dormitory where about 25 other engineers, graduates from different colleges, were living. It was very social and you made a lot of young friends early in the game. I did not think much of the idea of being a surveyor, or even a surveyors, helper; the higher-up surveyors only got $125 a month, and had been there quite a long time. So, I asked to be changed to underground sampling, where I would see the mine faces every day and learn more about mining. In about three months, I became an underground sampler and remained at this for a year, but in three months I was promoted to head sampler, with six people under me.

Jan 10, 1963

By Frederick Prime

IN this second supplementary list no titles to which an * is. Pre-fixed have been seen by the compiler; and he will be most thankful to have, any omissions or inaccuracies in the list sent to him to be published as a third supplement in the next volume of- the Trans-actions. The author is indebted to Prof. J. J. Stevenson, of New York, Prof. P. R. Uhler and John W. M. Lee, Esq., of Baltimore, and Lloyd P. Smith, Esq., of Philadelphia, for valuable assistance. OFFICE, ALLENTOWN IRON COMPANY, 230 SOUTH THIRD STREET, PHILADELPHIA, September 5th, 1881. ALABAMA. Geological Survey of Alabama. Report of Progress for 1879 and 1880, by Eugene A. Smith, State Geologist. Montgomery, 1881. 8vo., 158 pp., and 2 maps. CALIFORNIA. Omit Report of Hon. T. Butler King, in Supplement 1. For Trash's Geology and Industrial Resources, etc., in Supplement I., read Tyson's, etc: Fremont's Memoir on Upper California, is also published as XXXth Congress, 1st Session. Senate Mis. Doe., No 148, and has a map. For Randall's Report in Supplement I, read Report of the Special Committee in favor of a Geological Survey, submitted by Mr. Randall, April 24th, 1851. a.d., 1851. 8vo., 1.9 pp. XXXIst Congress, 1st Session, Sea. Ex. Doc., No. 47, Part 2 [Part 1 is Tyson's Report.] Report of the Secretary of War in further compliance with the Resolution of the Senate, calling for Copies of

Jan 1, 1881

By Eugene H. Cowles

Now that a determined public effort is being made on this side of the Atlantic to create a steel ship-building industry, the materials that are demanded for this purpose assume a new interest to the American metallurgist. In the past, the uses of metals in this country have been almost exclusively connected with the land, while in England their application to marine purposes has been equal in importance to that on shore. In the future the same should be the case here. This is the reason for bringing a somewhat nautical or rather naval topic before a body the chief interests of which are supposed to lie in the mines and mountains of the interior of the country. A modern war-ship or " ocean-grayhound" (like the City of Paris) is an epitome of philosophy and human skill. In her graceful lines we have, as Ruskin might quaintly say, a " builded geometry ;" while in her wonderful machinery for motion, offensive and defensive, we have the summation of the ideas of a host of students who have, at one time or another, during the course of a hundred years of her evolution, contributed their intellectual mites to render her a thing of beauty and of power. Notwithstanding her present perfection, the modern ship contains room for further improvement. One of the most important things about her is the propeller. This active member is of more impor-

Jan 1, 1890

By D. W. Gillmore, C. C. Wright

DEWATERING is a major problem in the preparation and utilization of fine-sized coals now being recovered in increasing amounts from colliery effluents, refuse banks, and silt ponds. Of the various methods which have, been proposed for dewatering fine coal, gravity drainage is probably the oldest and most widely used, and yet little information on this subject has been published. Consequently a laboratory investigation of gravity drainage phenomena was undertaken not only to provide basic data for predicting the drainage behavior of fine coals in cars, bunkers, basins, and silos, but also to obtain some understanding of the moisture retention properties of fine coal. Because of practical interest in the problem, a reproducible laboratory technique, which simulated plant conditions as closely as possible, was developed for the evaluation of drainage variables. The ap- paratus selected consisted of vertically-mounted lucite columns, nominally 4 to 8 ft in length and 2, 3 or 6 in. in diam; the bottom of the column was provided with a rubber stopper through which was inserted a -in. diam drainage tube; a wad of glass wool was placed on the upper part of this outlet tube to retain the coal and a plug was temporarily located at the lower end to prevent drainage during charging of the column, see Fig. 1. The most satisfactory testing procedure is as follows: 1—The fine coal, which has been thoroughly

Jan 1, 1953

By R. W. Raymond

The sudden death of Dr. Drown, on Nov. 17, 1904, brought to multitudes the pang of personal loss. Of all those who, as students at Lafayette College, the Massachusetts Institute of Technology and Lehigh University, were brought under his influence, not one can have forgotten him, and all will now acknowledge, with an unfading gratitude, what they owe in professional equipment to his wise, clear, skillful guidance, and in character to his sympathetic, stimulating personality. Outside of this wide circle, the experts of both hemispheres will lament the departure of one who, in his department of scientific investigation, both knew what work was needed, arid how to do it so that it needed not to be done again. The older members of the Amierican Institute of Mining Engineers will remember with gratitude the part he took, as Secretary from 1873 to 1884, in promoting the interest of that organization, and in shaping the plan and policy which it has followed with such noteworthy success. And, in addition to all these (though partly included among them), there are a host of friends, who can scarcely think of the public loss by reason of their own. Thomas Messenger Drown was born March 19,1842, at Philadelphia, Pa. His parents were natives of New England; and he was the youngest of their three sons. He received his preliminary education in the public schools and the High School of Philadelphia, from which he was graduated in 1859. Be-

Jan 1, 1906

By W. V. Youdelis, W. H. Bear, G. Cochrane

HERETOFORE, there has been very little study of the effects of various metallurgical factors on the behavior of thermoelectric materials, the need for which is evident if optimum processing and design of thermoelectric devices is to be realized. Accordingly, we have undertaken such an investigation on the thermoelectric materials bismuth and Bi-Sb alloy and in this paper present some preliminary results which merit consideration, in particular the relatively high thermoelectric power and figure of merit values obtained for the Bi-12Sb (at. pct) alloy powder compacts. The thermoelectric parameters for ingot and powder compact specimens are determined and the results are compared with published data for single crystals. Preparation of Materials. The bismuth and antimony used in this investigation are six nines pure. Melting and casting of the ingots was carried out in air for expediency, since most oxidation unavoidably occurs during the preparation of the powder by filing of the ingots. Chill cast ingots of pure bismuth were prepared by pouring the melt into split copper chill molds, and unidirectionally solidified ingots of bismuth and Bi-Sb alloy were obtained by slow directional cooling in pyrex tubes. All melts remained bright during melting and casting, indicating minimum oxidation. Powder for the powder compact samples was obtained by filing the ingots with a fine and coarse file to give a variation in the particle size of the compacts. The particles in the fine powder compacts varied in size from approximately 28 pct less than

Jan 1, 1970

By F. E. Bash

IN recent years, there have been a number of experiments conducted to determine the rates of heating and cooling of various sizes and shapes of steel ingots. Up to date, however,-most of the published data has dealt with small sized ingots, the largest being an 18-in. (46 cm.) cube, the data on which was presented before the Iron and Steel Institute in May, 1918, by E. F. Law. It is due to thus lack of information on the rate at which large ingots absorb heat and come to temperature that the heating- practice varies so widely in different plants. One of the questions over which there is much debate is the proper rate of heating of large ingots for forging and the time actually required for the center of a mass of steel to come to forging temperature. As a continuation of experiments described by M. E. Leeds1 and at the request of Mr. G. R. Norton of the Sizer Forge Co. and Mr. R. C. Drinker of the Emergency Fleet Corpn., the test described in this paper was carried out on a 24-in. (61 cm.) round ingot and the rate of heating and cooling determined under regular production conditions. The ingot had been partly forged at one end but, on developing a flaw, had been scrapped so that it was available for test. The size and shape of the ingot and its position in the furnace are shown in Fig. 1.

Jan 9, 1919

By Robert Burrows

IN preparing this paper the object has been to set forth facts relating to illumination problems, which, judging from the results realized in the iron and steel and other industries somewhat similar to mining, will tend toward furthering safety, production, and contentment of employees, as well as economy of operation in mines. By applying the principles of illumination with the assistance of modern appliances, the full benefits in efficiency may be derived from improvements already made in other details of mine operation. The lighting of a typical coal mine may be divided into four distinct parts: 1, The lighting of the buildings about the top; 2, the lighting of the working faces; 3, general illumination at the bottom; and 4, special applications of lighting. The lighting of buildings about the top may be treated in the same manner as that of any other industrial plant, for we have a boiler room, an engine and generator room, a forge, a machine shop, and a hoist room. These can be well and efficiently lighted by the use of 100-watt tungsten-filament multiple lamps with proper reflectors so spaced and suspended that a power consumption of from ¼ watt per square foot in the boiler room to 1 watt per square foot in the machine shop is obtained. The methods that apply to this kind of lighting have been ably treated by a number of authors,1 and for this reason a detailed discussion is unnecessary.

Jan 11, 1915

By D. W. Gillmore, C. C. Wright

DEWATERING is a major problem in the preparation and utilization of fine-sized coals now being recovered in increasing amounts from colliery effluents, refuse banks, and silt ponds. Of the various methods which have, been proposed for dewatering fine coal, gravity drainage is probably the oldest and most widely used, and yet little information on this subject has been published. Consequently a laboratory investigation of gravity drainage phenomena was undertaken not only to provide basic data for predicting the drainage behavior of fine coals in cars, bunkers, basins, and silos, but also to obtain some understanding of the moisture retention properties of fine coal. Because of practical interest in the problem, a reproducible laboratory technique, which simulated plant conditions as closely as possible, was developed for the evaluation of drainage variables. The ap- paratus selected consisted of vertically-mounted lucite columns, nominally 4 to 8 ft in length and 2, 3 or 6 in. in diam; the bottom of the column was provided with a rubber stopper through which was inserted a -in. diam drainage tube; a wad of glass wool was placed on the upper part of this outlet tube to retain the coal and a plug was temporarily located at the lower end to prevent drainage during charging of the column, see Fig. 1. The most satisfactory testing procedure is as follows: 1—The fine coal, which has been thoroughly

Jan 1, 1953

By Milan Matula

One of the main characteristics of the development of rock mechanics in some countries is a close cooperation between experts in rock mechanics and workers in related fields, including soil mechanics and engineering geology. The purpose of this chapter is to outline the contribution that engineering geology can make to rock mechanics and to present a few examples of engineering geology studies that have been used in solving some practical rock mechanics problems. Engineering geology investigations dealing with the influence of geological factors on the physical properties of rock materials and rock masses fall into three main categories : 1) Systematic study and correlation of the physical properties of the main rock types with the petrogenetic evolution that caused the differences in the properties of these various rock types. 2) Study of the heterogeneity and anisotropy of both rock materials and rock masses. 3) Delimitation of rock masses which are approximately uniform in physical properties (quasihomogeneous units). Delimiting of the quasihomogeneous rock masses is the main contribution that the engineering geologist can make to rock mechanics. This delimiting is based on the evaluation of many complex geologic factors, not on test results alone, and therefore is most effectively done by trained engineering geologists. The foregoing types of studies are being used in Czechoslovakia for several purposes, including : 1) the compilation of regional engineering petrologic data-that is, the systematic definition of the main rock types of the country in terms of their representative physical characteristics;

Jan 1, 1970

By D. K. Crampton

NEARLY everyone who has not had the benefit of study in the field of metallurgy subscribes to a persistent and enthusiastic belief in the legendary lost art of hardening copper. This of course supplies a perfect introduction to a chapter of information on copper and its alloys, since the dissipation of fallacies and superstitions affecting an art probably constitutes the best method of getting at its real substance. Metals are hardened, but also embrittled, by a plurality of impurities. In the modern technology of copper-base metal products, we are familiar with a great host of materials, passing from one extreme of dead soft copper better than 99.9 pct pure, which in the form of wire about as thick as a match will stand hundreds of full twists in a 12-in. length, to an alloy containing less than 3 pct of alloyed substance possessing the strength of pretty good steel and capable of manufacture into razor blades, should we suddenly be deprived of steel; certainly a much better material for this purpose. Every copper alloy known to primitive man lies in some inter- mediate position and the ancient bronzes that have been found all over the world wherever an early civilization existed are usually contaminated by such impurities as sulfur, oxygen, antimony, arsenic, iron, or other materials, so that they could not possibly conform to any modern intelligent specification insuring the best combination of useful properties in alloys of their type and would go

Jan 1, 1953

By W. White, C. S. Barrett, R. M. Mueller

THIS communication reports film-recorded low-energy (-100 kev) proton blocking patterns'-3 for hcp and wurtzite crystals. In particular the sequence of relative line intensities* (corresponding to planar blocking) of common hcp metals is compared with those of the wurtzite semiconductors CdS and CdSe. The results show that the sequence is characteristic of structure. For closely similar structures such as those of CdS and CdSe, differences of line intensity attributable to the difference in atomic number, 2, of the scattering centers may also be seen. The apparatus and techniques used in this work were identical with those reported previously in a study of cubic systems.3 All metals were given standard metal-lographic etches, and the semiconductors cleaved, immediately prior to introduction to the vacuum system. Fig. 1 shows the unit cell of the wurtzite structure, and the geometry used to obtain the [1120] and [0001] patterns of Fig. 2. The axial ratio, c/a, for all ma- terials of Fig. 2 is close to 1.63. The patterns are then directly comparable in linear dimensions inasmuch as they have been reproduced at the same overall magnification of the patterns. (Overall magnification is proportional to the product of film-to-target distance and printing magnification. Thus the 1/6-in.-diam beam passage hole in the center of the film need not appear of uniform size in the prints.) The patterns for a given orientation, though similar

Jan 1, 1970

By Robert Roberts

(Butte Meeting, August, 1913.) IN order to obtain data on the thermal effect of the blast-furnace jacket and oil the water consumption in these jackets a series of tests were run on the 56 by 180 in. blast furnaces at the Great Falls Reduction Department of the Anaconda Copper Mining Co., at Great Falls, Mont. The arrangement of the jacket is shown in the transverse section of one of the furnaces (Fig. 1) on which the tests were made. The nose, spout, and breast jackets have independent water supplies and discharges. The end and side jackets are connected in pairs, as regards water supply, the feed water entering at the bottom of the lower jacket and overflowing into the bottom of the jacket immediately above it, and discharging into an independent overflow pipe for each pair of jackets. Tests were run on the main side and end jackets, the breast jacket, the spout, and the nose. Measurements were taken of the quantity of water discharged per minute and the rise in temperature of the water in its passage through the jacket. The product of these two results, expressed in the proper units, evidently gives the number of units of heat removed per minute by the water. Sufficient work was done on each type of jacket to determine its behavior under different conditions, and the results from each set of conditions were checked by repeating the work from three to six times.

Jan 7, 1913