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By Stanley Lefond

Industrial Minerals, often called the Cinderella Minerals or the Building Blocks of industry continued their growth patterns through 1973, although profits were slightly lower due to the cost-price squeeze. Most of the individual reports which follow indicate growth rates of 3-15%. Surprisingly such commodities as sulfur held firm in spite of the over supply in the Canadian gas fields; cement was in short supply while the asbestos industry reported a worldwide shortage of group 4 and 5 fibers. Talc and perlite production set new records. In synopsis, 1973 was a productive year for industrial minerals. However 1974 onward appears to be one of contradiction. The unsettled conditions of world economics, the energy shortage, compounded by the Arabs oil embargo have created great problems for all industries. The high energy consuming segments of the Industrial Minerals field will be under intense pressures. On the other hand limestone, lime and perhaps trona, nahcolite might be consumed in ever increasing tonnages in SO2 removal systems connected with smelters and coal-fired power stations. The effects of the proposed changes in the staking, claiming and exploitation of federal lands by the BLM may also have serious repercussions not only to the industrial minerals field but to the entire mining industry. 1974-1975 will certainly be ear-marked as a year of frustrations and difficult decisions.

Jan 2, 1974

By Gordon G. Bentle, W. P. Fishel

GREINER, Marsh, and Stoughton1 have reviewed the literature in a monograph on the iron-silicon system. The lack of agreement among the various studies may be due to the difference in the purity of materials in some cases. The results of the X-ray method indicate only a general rather than a specific limit of the y loop. The iron-titanium system was investigated by Roe and Fishel,' whose results are used in determining the iron-silicon-titanium y loop. The literature indicates that no study has been made thus far of the iron-silicon-titanium system in the y loop region. Experimental Procedure The alloys were made from Armco iron, 99.86 pct Si, and 98.5 pct Ti. The titanium contains 1.07 pct Fe. The Armco iron contains 0.01 pct C, 0.005 pct Si, 0.02 pct Mn, 0.006 pct P, 0.01 pct S, and 0.04 pct Cu. A dilatation sample of Armco iron was prepared in the same manner as were the other samples. Several dilatation runs indicated that Ac3 begins at 905°C and ends at 910°C, which compares favorably with the study of Wells, Ackley, and Mehl' employing specially purified iron. All alloys were melted in an induction furnace in Alundum crucibles and were top poured into baked core sand molds. The ingots weighed about 600 g as cast. Dilatation samples of 4 in. by % in. diam were taken from the bottom end of the ingot, from which turnings for analysis were taken. Turnings from each end of two of the samples indicated that the alloys possessed uniform silicon content. A hole was drilled halfway through each end of a 4 in, dilatation sample. A chromel-alumel thermocouple was inserted in each hole and the surrounding metal peened in to hold the thermocouple in place. Fig. 1 represents the dilatation apparatus. The heating unit is an Alundum tube wound with resistance wire; the dilatation tube is a McDanel combustion tube; the push rod is zircon; the dial gage is graduated in 0.0001 in. and was vibrated to prevent sticking. A blank run over the temperature range of interest gave no significant dilatation. The thermocouples were attached to a multiple recording micromax which indicated the temperature at each end of the sample at 35 sec intervals. A Lindberg control unit governed the rate of heating of the furnace, and lowering or raising the

Jan 1, 1957

By R. A. Cunningham, A. S. Murray

If a dense fluid such as mud or water is used for circulation, the formation drilled is influenced by a hydrostatic pressure. This pressure depends on hole depth arid drilling fluid density. Laboratory tests indicute that drilling rates in many forri~ations are decreased with increased pressure,—in some cases as much as 90 per cent. A comparison between laboratory and field tests indicates that drilling fluid head affects drilling rates in the field approximately the, same as in the laboratory. Drillirrg rates of many formations are increased by reducing drilling fluid head. INTRODUCTION For many years it has been noted that field and laboratory drilling rate tests did not agree even when the formations tested were the same. For instance, tests of some shales by the Hughes Tool Co. laboratory indicated drilling rates approximately 20 to 30 ft/hour, whereas in the ground this shale would drill only 3 to 5 ft/hour. A possible reason for this discrepancy is the effect of the high pressure which the drilling fluid exerts against the formation at the bottom of the hole. Consider a small element of rock (Fig. II that is to be removed by a rock bit. If the hole is filled with mud or water. the upper surface of the rock element is subjected to a pressure which depends on hole depth and fluid density. The mass of earth around this rock element presses against the circumferential surface and the lower surface. Because of the probability of shearing stresses between the rock element and the surrounding rock, this element is not under true hydrostatic stress. However, as a first approximation for test purposes the rock element was assumed to he under hydrostatic stress. The effect of hydrostatic pressure on some physical properties of rock has been studied.1,2,3 These tests show that the "differential" compres-sive stress:': necessary to cause rup- ture in rock cylinders is greater when tested under high hydrostatic pressure than when tested under atmospheric conditions. These tests were made with pressures greater than 20,000 psi which is in excess of those normally encountered in oil well drilling. Similar tests were made by the Bureau of Reclamation' using pressures equivalent to those encountered in oil well drilling. Again the "differential" compressive stress necessary to produce failure increased with increasing hydrostatic pressure. These tests indicated that drilling rates would probably decrease. Correlation between these tests and drilling tests was not practical. The purpose of this work is to study the effect of mud column pressure on drilling rate, assuming that the material drilled is in a state of hydrostatic strcss. This problem was initially investigated in the laboratory using variable bit loads and confining pressure;. Confirmation of laboratory results was obtained in the field from a series of carefully controlled drilling tests. Because of the necessity of testing many different types of formations. only results from representative formations will be presented here.

Jan 1, 1956

By C. M. Tucker, Kent R. Van Horn, W. P. Sykes

RECENT investigations of the molybdenum-carbon alloys have been reported by Becker and Ebert1‡, Westgren and Phragmén2, T. Takei3, and H. Tutiya4. Takei3 studied the Mo-C system by employing metallographic and X-ray methods, and the other publications described the determination of the crystal structure of the molybdenum carbides. In exploring this system by a technique previously applied to the tungsten-carbon series5, the results of Takei were confirmed with two definite exceptions; i.e., first the composition of the eutectic, and second the nature of the carbon-fish intermediate phase. Consequently, a more thorough examination of the molybdenum-carbon constitution was initiated in an effort to correlate the data supplied by the microstructures, diffraction patterns and chemical analyses. METALLOGRAPHIC INVESTIGATION A briquette of molybdenum powder when heated in a carburizing atmosphere at 1500° to 1600° C. for several hours develops the carbon-rich layer shown in Fig. 1. The carburization was accomplished by placing the briquette in a carbon tube, which was heated in the hydrogen atmosphere of an alundum muffle wound with tungsten resistor. While the macrostructure indicates two distinct shells, and suggests the possibility of two carbon-rich phases, no evidence of this condition could be detected by the microscope, which revealed but one high-carbon constituent. This carbide forms next to the molybdenum as a relatively

Jan 1, 1935

By Lawson P. Entwistle

One of the important reserves of mangani-ferous iron ore is at Boston Hill, near Silver City, New Mexico. The area consists of a faulted block of gently dipping Lower Paleozoic shale, dolomite, limestone and sandstone, which has been intruded by a roughly circular mass of quartz-bearing monzonite porphyry and subordinate dikes. Prom a noselike protuherance of the intrusion radiate many premineral faults, which have localized much of the hypogene mineralization. Three important stages of hypogene mineralization can be recognized: (I) mesitite, a manganiferous iron magnesite, (2) quartz sulphides, and (3) barite-galena The carbonate stage is widespread but stronger near the intrusion. The quartz may have been derived from hydrothermal alteration of the igneous rocks. Barite-galena is most important in the Chloride Flat mining district, about one mile north, where argentiferous galena provided silver for the supergene ore. The hypogene carbonate, lean in iron and manganese, has been oxidized and consequently enriched by meteoric waters containing an excess of oxygen and carbon dioxide to form ore bodies of intimately mixed hematite and pyrolusite. The ore bodies, at one place attaining a length of 1600 ft., a width of 300 ft., and a thickness of 25 ft., are largely confined to areas of brecciation and to spreads from faults in Silurian dolomite beneath soft Devonian shale. Boston Hill comprises three rolling hills southwest of and adjoining the town of Silver City (pop. 5044), Grant County, N. Mex. The mining district covers less than 2 sq. miles. Silver City, on a branch line of the Atchison, Topeka, and Santa Fe Railway, is a supply point for the important mining communities at Santa Rita, Hurley, Hanover, Tyrone, and Mogollon. The Chloride Flat mining district adjoins Boston Hill on the north. History and Production Bonanza-type silver ores were discovered in the Chloride Flat mining district during the silver boom of the seventies and eighties, at which period it has been credited with as much as $5,000,000 production. In 1916 manganiferous iron ore was first shipped from the Boston Hill mining district to Pueblo, Colo., where it was mixed with manganese ore from Lead-ville and smelted into spiegeleisen. During 1926 and 1927 the Colorado Fuel and Iron Co. mined and churn-drilled part of the district. Mining operations ceased during the depression of the thirties, but production was resumed in 1937. Since 1916 the Boston Hill mining district has produced about 600,000 long tons of ore averaging about 12 per cent manganese and 35 to 40 per cent iron.

Jan 1, 1949

By Lawson P. Entwistle

One of the important reserves of mangani-ferous iron ore is at Boston Hill, near Silver City, New Mexico. The area consists of a faulted block of gently dipping Lower Paleozoic shale, dolomite, limestone and sandstone, which has been intruded by a roughly circular mass of quartz-bearing monzonite porphyry and subordinate dikes. Prom a noselike protuherance of the intrusion radiate many premineral faults, which have localized much of the hypogene mineralization. Three important stages of hypogene mineralization can be recognized: (I) mesitite, a manganiferous iron magnesite, (2) quartz sulphides, and (3) barite-galena The carbonate stage is widespread but stronger near the intrusion. The quartz may have been derived from hydrothermal alteration of the igneous rocks. Barite-galena is most important in the Chloride Flat mining district, about one mile north, where argentiferous galena provided silver for the supergene ore. The hypogene carbonate, lean in iron and manganese, has been oxidized and consequently enriched by meteoric waters containing an excess of oxygen and carbon dioxide to form ore bodies of intimately mixed hematite and pyrolusite. The ore bodies, at one place attaining a length of 1600 ft., a width of 300 ft., and a thickness of 25 ft., are largely confined to areas of brecciation and to spreads from faults in Silurian dolomite beneath soft Devonian shale. Boston Hill comprises three rolling hills southwest of and adjoining the town of Silver City (pop. 5044), Grant County, N. Mex. The mining district covers less than 2 sq. miles. Silver City, on a branch line of the Atchison, Topeka, and Santa Fe Railway, is a supply point for the important mining communities at Santa Rita, Hurley, Hanover, Tyrone, and Mogollon. The Chloride Flat mining district adjoins Boston Hill on the north. History and Production Bonanza-type silver ores were discovered in the Chloride Flat mining district during the silver boom of the seventies and eighties, at which period it has been credited with as much as $5,000,000 production. In 1916 manganiferous iron ore was first shipped from the Boston Hill mining district to Pueblo, Colo., where it was mixed with manganese ore from Lead-ville and smelted into spiegeleisen. During 1926 and 1927 the Colorado Fuel and Iron Co. mined and churn-drilled part of the district. Mining operations ceased during the depression of the thirties, but production was resumed in 1937. Since 1916 the Boston Hill mining district has produced about 600,000 long tons of ore averaging about 12 per cent manganese and 35 to 40 per cent iron.

Jan 1, 1949

By R. H. Hiltz, N. J. Grant

Solid-solution titanium-cerium alloys, cold-rolled to 0.010 in. thickness, and annealed, were internally oxidized to produce a fine dispersion of CeO2 in the titanium matrix. The oxidized alloys were cut into sheet stress-rupture specimens and tested for rupture life at 426°C, 538°C, and 648°C. There was noted an improvement in strength over that of pure titanium, the internally-oxidized alloys showing curves with a much flatter slope on the log stress—log rupture life plot, characteristic of the stable metal-metal oxide class of alloy. DURING the past 3 to 4-year period, considerable interest has been aroused by the potential offered by alloys based on the ultra fine dispersion of a hard insoluble phase in pure metals or solid-solution alloys for use at high temperatures. The impetus to the development and study of such alloys was provided by Irmann.1,2 through the success of the SAP alloy (pure aluminum containing about 12-14 volume pct of A12O3). Subsequent studies have thrown light on the true potential of this class of alloys in the remarkable stability of the structure after long-time exposure at high stresses and high temperatures.a-5 While success has been demonstrated in the special case of the A1-Al2O3 alloys, and more recently

Jan 1, 1959

By R. L. Huntington, Frank P. Vance, George F. Russell, Robert Thompson

With the advent of higher pressures in the operation of natural-gas transmission lines, the removal of water vapor from the gas has become increasingly important in order to prevent condensation or formation of gas hydrate from slowing down or stopping the flow of gas. Intelligent design of these dehydration or gas-drying plants has been hampered through the Iack of experimental data on the water vapor content of natural gas at elevated pressures. In view of this need, this present investigation was sponsored by the Southern Natural Gas Co. in the Chemical Engineering laboratories at the University of Oklahoma Research Institute. Experimental results were obtained on the water-vapor content of natural gas up to 2000 lb. per sq. in. at atmospheric temperatures. The water content at 2000 lb. is approximately two thirds as much as it is at 1000 Ib. Deviations from the ideal gas laws vary directly with pressure and indirectly with temperature. Introduction The removal of water vapor from natural gas is an important operation in connection with the production and transportation of this commodity because: I. Liquid water accelerates internal corrosion of a pipe line. 2. Accumulation of water at low points in a pipe line reduces markedly its capacity. 3. Gas hydrates, icy snowlike growths, form readily under high pressure in the presence of the lower hydrocarbons and water, often plugging up the pipe line. In order to design dehydration plants for stripping the gas of its water content, it is essential that the engineer. have a knowledge of the saturated or equilibrium water-vapor content of the gas to be processed. With the gradual increase of operating pressures around gas-producing wells and pipe lines, it was observed that the quantity of water recovered from dehydration plants or condensed in colder lines was considerably greater than had been expected from calculated contents, based on vapor-pressure data taken from steam tables. This observation prompted a number of investigators, for instance, Laulhere,3 Dea-ton,l and Hammerschmidt2 to carry out experimental work at pressures up to 600 lb. per sq. in. in order to determine quantitatively the water content of various gases. Sage, Lacey, et al.4,5 have recognized more recently the need for such data at higher pressures, but their work was done at temperatures of 100ºF, and higher. Since hydrate formation usually, if not entirely, occurs at temperatures below 100ºF., the present investigation was confined to the . lower temperature range at pressures from 600 to 2000 lb. per sq. in. gauge.

Jan 1, 1945

By Charles R. Fettke

BefoRe the Drake well on Watson Flats below Titusville, Pa, inaugurated the modern petroleum industry on Aug. 28, 1859, a considerable industry, based on the manufacture of mineral oils through the destructive distillation at relatively low temperatures (750' to 800' F.) of cannel coals and shales in closed, air-tight retorts, had already sprung up in Europe and America because of the increasing cost of animal and vegetable oils and fats and the growing demand for illuminating and lubricating oils. In 1860, eight out of 55 such coal-oil companies in the United States had plants located in Pennsylvania.' Of these, the Lucesco Works, costing $120,000, situated near Kiskiminetas Junction, was the largest operating in the country. It was equipped with 10 revolving 2.5-ton retorts and 16 stills for rectifying the oil, each holding 2000 gal. The total output of crude oil was almost 6000 gal. per day.2 The discovery of an abundant supply of natural petroleum by the Drake and other wells stopped the distillation of coal oil in America. Most of the smaller plants were closed and others were converted into petroleum refineries. At present, in spite of the temporary over-production of petroleum, the coal and oil-shale carbonization industries are again attracting the attention of far-sighted oil companies who realize that the gradual exhaustion of the American petrol-

Jan 1, 1923

By Charles R. Fettke

BefoRe the Drake well on Watson Flats below Titusville, Pa, inaugurated the modern petroleum industry on Aug. 28, 1859, a considerable industry, based on the manufacture of mineral oils through the destructive distillation at relatively low temperatures (750' to 800' F.) of cannel coals and shales in closed, air-tight retorts, had already sprung up in Europe and America because of the increasing cost of animal and vegetable oils and fats and the growing demand for illuminating and lubricating oils. In 1860, eight out of 55 such coal-oil companies in the United States had plants located in Pennsylvania.' Of these, the Lucesco Works, costing $120,000, situated near Kiskiminetas Junction, was the largest operating in the country. It was equipped with 10 revolving 2.5-ton retorts and 16 stills for rectifying the oil, each holding 2000 gal. The total output of crude oil was almost 6000 gal. per day.2 The discovery of an abundant supply of natural petroleum by the Drake and other wells stopped the distillation of coal oil in America. Most of the smaller plants were closed and others were converted into petroleum refineries. At present, in spite of the temporary over-production of petroleum, the coal and oil-shale carbonization industries are again attracting the attention of far-sighted oil companies who realize that the gradual exhaustion of the American petrol-

Jan 1, 1923

By F. L. Holderreed

A choosy in what they would smelt. The furnace charge had to be coarse, and it had to be rich. They discarded fines in excess of about 1/10 the total weight. They wanted 10% copper content and fussed about anything with as low as 5%. They concentrated the copper content of the charge as much as they could by prior selection. They roasted off enough sulfur to further enrich the copper content of the succeeding fall of matte (a melt of cuprous and ferrous sulfides or Cu2S.FeS). Then they desulfurized the iron and fluxed it by carefully adding silica (quartz, not silicates) for a slag of lower density than the cuprous sulfide (Cu2S or white metal). After skimming off the slag, they further desulfurized the white metal by blowing the molten bath with compressed air. The result was blister copper. Yesterday Their techniques and furnaces? Some experimented with mechanically rabbled roasters, but their standard roasting practice was burning coarse sulfide ore in 250-ton heaps. These heaps, approximately 24 x 24 x 6 ft, were burned for about 75 days down to 6-10% sulfur. The turnaround time for a given roasting position was 100 days. Assuming the base was a hearth, the calculated rate of treatment was on the order of 0.004 tpd per sq ft.

Jan 1, 1971

By Edwin M. Chance

During the last decade many conditions have been encountered that have materially increased the cost of the production of coal. As in most cases it has not been practicable to increase the selling price of such coal sufficiently to insure the necessary margin of profit, the mine management has been forced to avail itself of what might be termed unusual means that costs might be held at as low a figure as possible. The so-called efficiency engineer has been called upon, costly power plants have been built and machinery has been installed to replace manual labor wherever possible. Another aid used recently to secure economies through the more intelligent production of coal, is the chemist. As the coal industry, barring the production of byproduct coke, does not at once give evidence of its need of the services of the chemist, the writer will endeavor to point out a few of the services that this branch of the staff has been able to render. The preparation of coal in the past has been carried on entirely upon an empirical basis, that is, the criterion adopted has been an ocular inspection. Unfortunately, the appearance of a coal and especially of an anthracite, has but little relation to its fuel value, and as long as coal is purchased for the heat that can be obtained from it by its combustion, the quantity of such heat that is purchased must be one of the principal desiderata in selecting or preparing a coal. Were coals purchased for use as bric-a-brac or for exhibition in museums it might be both wise and just to purchase them upon their appearance. After 4 or 5 years of investigation the fact has been established that coals of very inferior appearance, and I now have special reference to anthracite, might and often did possess heating and burning properties superior to those possessed by bright coals which in the past had commanded considerable and uniform premiums in the market. This being the case the question arose as to whether the trade could be convinced of this fact. While at first some difficulty was experienced in establishing the quality of such dull coals, still it was found that the real obstacle to the sale of these materials in the past had been the fact that the coal producers' own sales departments felt convinced of the inferiority of this type of fuel and when complaints were registered they were given ready credence. Upon convincing the sales department of the quality of this type of fuel, but

Jan 1, 1917

By Fritz Wald, Richard W. Stormont

lHE general constitution of a number of metal-lead telluride and metal-tin telluride systems has recently been studied in an effort designed to furnish background information for the study of degradation mechanisms on junctions between thermoelectric power generation materials and metals.1"4 This paper reports further results of that effort. It was found that cobalt-lead telluride constitutes a stable pseudobinary section through the ternary Co-Pb-Te system. Materials used in the study were lead and tellurium of semiconductor-grade purity (American Smelting and Refining Corp., 99.999+ pet). Cobalt (Johnson Matthey & Co., 99.999 pet purity) was used in the form of slices cut from rods of 5 mm diam. Twenty- gram charges of the alloys were melted in evacuated quartz ampoules. Thermal analysis, as described previously,2'3 and metallographic and X-ray diffraction methods (Debye-Scherrer photographs) were used as investigative tools. Substantial difficulties were encountered in polishing, as reported previously for the lead telluride-iron system.3 A number of different etches were used, including dilute aqua regia, Murakami solution, an etch containing copper nitrate,3 and HC1-HNO3-acetic acid-water mixtures. None of these etches gave consistent results over the complete range of cobalt concentrations. On the alloys containing bulk cobalt in the form of primary

Jan 1, 1969

By Frank Marotta, Louis B. Lesem, Frank Greytok, John J. McKetta

Although one of the primary variables in the calculation of the flowing bottom-hole pressure in gas wells from surface measurements is the temperature at any point and its distribution in the flow-string, only few experimental data are available in the literature and little attention has been given to analysis of the problem. Virtually all of the recently published methods of calculating flowing bottom-hole pressures depend on the assumption that either the temperature is constant at some average value or that the variation is linear with depth. The purposes of this work are to analyze the problem theoretically and to verify the analysis by comparison with experimental data so that practical problems in the analysis of the behavior of gas wells can be solved with greater accuracy, reliability, and ease. MATHEMATICAL OUTLINE OF PROBLEM Assuming that: 1. The mass velocity and chemical composition of the gas stream are constant and in normal gas well operations, the change in linear velocity in the entire flow-string is trivial, 2. The product of the density and heat capacity of the gas is constant, 3. No horizontal temperature gradient exists in the gas stream, 4. Net flow of heat by conduction within the formation and in the gas stream in the vertical direction is trivial in magnitude and can be neglected, 5. The regional vertical geothermal gradient is constant, and 6. The temperature of the gas entering the borehole is constant, and equal to that of the reservoir, a set of two simultaneous, linear partial differential equations with appropriate boundary conditions was derived to describe the temperature distribution in the gas stream and the surrounding formation. These equations were solved by operational techniques for the distribution of temperature in the gas stream. The resulting integrals were evaluated numerically on an IBM 604 at the Machine Accounting Div. of the Railroad Commission of Texas. DERIVATION OF FUNCTIONS FOR THE DISTRIBUTION OF TEMPERATURE The physical system is a circular hole of radius a in an infinite medium with thermal conductivity K, density p8, and heat capacity c,. Under shut-in conditions the well is in thermal equilibrium with the surroundings and the increment in temperature is given by - ?T3/L x. Gas of density pg and heat capacity c.. flows upwardly through this hole in the direction of increasing x with a linear velocity W. Writing a heat balance on an element of gas ?x in thickness, convective heat transfer + conductive heat transfer + energy required to lift a unit mass of fluid = change in energy content. pa2W po Co To - pa2Wpo Co To x+xx - 2apK?x ?T8/?r r=a - Wpa2 po?x/778 = CoPopa2?x?To/?t... Dividing by (copopa2?x) and taking the limit as ?x tends to zero, -W (?To/?x + 1/778Co) + 2 K/a Po Co ?T3/?r r=u = ?To/?t

Jan 1, 1958

By G. A. Koehler

The Hiawatha mine, a producer of iron ore, is near the City of Iron River, in Iron County, Michigan. This mine, operated by The M. A. Hanna Co., has been chosen by the author as a typical iron mine in this district that is using the cut-and-fill mining system. General Geology The Hiawatha ore body lies along the steeply dipping north limb of a syncline that closes around on the east end to form a bathtub-shaped structure. Throughout this major structure there are very many smaller wrinkles or folds, which vary the direction as well as the thickness of the ore body. The total length of the ore formation with minor interruptions so far developed is about 3600 ft. The ore body throughout the entire present depth of 2000 ft. has averaged approximately 40 ft. in thickness; it is somewhat narrower at the upper levels and shows a marked increase in thickness on the bottom levels. This increase in thickness probably indicates that the bottom of the trough is near or that a major monoclinal fold has been encountered, which flattens the ore and gives apparent horizontal thickening. The footwall of this ore body is generally a black, graphitic slate, very rich in iron sulphides, quite combustible when exposed to air, and very treacherous to handle during mining operations. The hanging wall, in most places, is a cherty, fairly hard iron formation, and in general stands quite well ill open stopes. There are places, however, where black slate is found in both the hanging wall and the footwall, which makes mining difficult, as the black slate tends to slough off after being exposed to air. In these places it becomes necessary to leave a scale of ore 5 to 6 ft. thick on both hanging wall and footwall, which is not recovered. Fig. I shows a typical vertical cross section through the Hiawatha ore body. Type of Stoping Because of the size and shape of the ore body and the hard, dense structure of the ore, sublevel stoping has been an efficient and economical method of extracting the ore. This method, with various minor changes, has been used since the mine was opened in 1893. There have never been any stope-filling operations, however, until recent years, when crushing of pillars and black-slate fires forced the issue and methods were arrived at to fill all stopes. Development of Deeper Levels Shaft sinking to deeper levels in development operations has been done successfully by two methods without interference or hindrance to production. These systems are: I. Sinking an auxiliary winze a short distance from the shaft, then drifting back to the shaft location and putting up a pilot raise through to the bottom of the shaft. This raise is always in the manway compartment of the shaft, so that no work is ever done under a cage or skip. A 20-ft.

Jan 1, 1946

By George Fancher, R. L. Whitting

A typical drilling mud from the Hastings oil field, Brazoria County, Texas, containing only 8 per cent (dry basis) of material of colloidal dimensions, which is largely illite, was concentrated to a density of 10.2 lb. per gal. and used in this study. The effects of water dilution, treatment with complex polyphos-phates, temperature and the time of heating upon the rheological properties of the mud were investigated. It was found that water plays an important part in chemical treatment and that sodium acid pyrophosphate and sodium tripolyphosphate were more efficient than other complex polyphosphates for chemical treatment. Muds treated with either of these chemicals manifested maximum reduction in viscosity and minimum filtration rates at low concentrations. Furthermore, .mud treated to minimum viscosity with either of these two chemicals was virtually unaffected by heat-treatment. Introduction The drilling of deep wells is dependent upon the use of drilling mud, and problems frequently arise concerning the effects on mud of temperature, prolonged heating and aging. The use of chemicals to control the rheological properties of mud is a well-established practice. Salts of weak organic acids such as sodium tannate or gallate were used at first until the complex phosphates of sodium were found to be more efficient. Consequently, it seemed important to investigate the reaction of a mud to chemical treatment with phosphates, temperature, heat-treatment and aging, particularly since previous work in the laboratory at the University of Texas had provided the particle-size distribution and mineral composition of Hastings mud. Properties or Mud Used in Experiments A large sample of the mud from a drilling well in the Hastings field, Brazoria County, Texas, was obtained directly from the circulatory system. Some of the general physical characteristics of the mud and other data are presented in Table I. Table i.—General Properties of Hustings Drilling Mud Alex- Cur-ander keet Well Well Depth when sample was taken, It.. 5720 5700 Weight. lb. per gal............... 9.5 0.8 Viscosity, sec. A.P.I.............. 47 60 Viscosity, Stormer, grams......... 80 Viscosity, centipoises............. 13 Filtration rate, c.c. per 30 min.a. . . 19.6 22.8 Salt content (chlorides), per cent... 0.13 0.12 pH............................. 8.9 8.9 The Alexander mud was used for the experimental work. Comparison with Curkeet mud indicates a considerably greater dilution but otherwise suggests similarity. The mineral composition and particle-size distribution of Curkeet mud (Table 2) are available (Fancher and Oliphant6). It is suggested that Alexander mud would have a similar composition.

Jan 1, 1943

By R. L. Whitting, George Fancher

A typical drilling mud from the Hastings oil field, Brazoria County, Texas, containing only 8 per cent (dry basis) of material of colloidal dimensions, which is largely illite, was concentrated to a density of 10.2 lb. per gal. and used in this study. The effects of water dilution, treatment with complex polyphos-phates, temperature and the time of heating upon the rheological properties of the mud were investigated. It was found that water plays an important part in chemical treatment and that sodium acid pyrophosphate and sodium tripolyphosphate were more efficient than other complex polyphosphates for chemical treatment. Muds treated with either of these chemicals manifested maximum reduction in viscosity and minimum filtration rates at low concentrations. Furthermore, .mud treated to minimum viscosity with either of these two chemicals was virtually unaffected by heat-treatment. Introduction The drilling of deep wells is dependent upon the use of drilling mud, and problems frequently arise concerning the effects on mud of temperature, prolonged heating and aging. The use of chemicals to control the rheological properties of mud is a well-established practice. Salts of weak organic acids such as sodium tannate or gallate were used at first until the complex phosphates of sodium were found to be more efficient. Consequently, it seemed important to investigate the reaction of a mud to chemical treatment with phosphates, temperature, heat-treatment and aging, particularly since previous work in the laboratory at the University of Texas had provided the particle-size distribution and mineral composition of Hastings mud. Properties or Mud Used in Experiments A large sample of the mud from a drilling well in the Hastings field, Brazoria County, Texas, was obtained directly from the circulatory system. Some of the general physical characteristics of the mud and other data are presented in Table I. Table i.—General Properties of Hustings Drilling Mud Alex- Cur-ander keet Well Well Depth when sample was taken, It.. 5720 5700 Weight. lb. per gal............... 9.5 0.8 Viscosity, sec. A.P.I.............. 47 60 Viscosity, Stormer, grams......... 80 Viscosity, centipoises............. 13 Filtration rate, c.c. per 30 min.a. . . 19.6 22.8 Salt content (chlorides), per cent... 0.13 0.12 pH............................. 8.9 8.9 The Alexander mud was used for the experimental work. Comparison with Curkeet mud indicates a considerably greater dilution but otherwise suggests similarity. The mineral composition and particle-size distribution of Curkeet mud (Table 2) are available (Fancher and Oliphant6). It is suggested that Alexander mud would have a similar composition.

Jan 1, 1943

By W. V. Kotlensky, H. E. Martens

In an earlier communication, Ref. 1, the authors presented the tensile properties and the changes in crystal structure and microstructure for pyrolytic graphite tested at 2750°C. It was suggested that changes in the structure may have an effect on the tensile properties of this material. Accordingly, tensile tests were run on a series of specimens, from one block of pyrolytic graphite, some of which were hot-worked by being strained at 2750°C, others of which were tested in the as-deposited condition. According to the manufacturer, General Electric Co., the polycrystalline material was deposited at 2100°C on a substrate of synthetic graphite by decomposition of a dilute natural gas mixture. The as-deposited material had a density of approximately 2.19 g per cc, and as shown in Fig. 1 had a structure of medium size growth cones which were regenera-tively nucleated. All specimens had a gage section 0.75 in. long by 0.06 in. wide by 0.1 in. thick with the thickness direction perpendicular to the basal planes. The testing method and equipment used have been previously described, Ref. 2 and 3. For both the hot-working and the testing the load was applied parallel to the basal planes; a cross-head speed of 1.5 x l04 in, per sec was used. All heating was done in an atmosphere of bottled helium.

Jan 1, 1962

By S. L. Couling, G. W. Pearsall

MOTT and Hainesl have summarized the available techniques for the examination of aluminum and some anisotropic metals under polarized light. Many of these techniques are rather complicated and cumbersome. This note presents a simplified procedure for using polarized light to obtain information about the crystallographic orientation of any particular grain in a magnesium alloy. Since other hexagonal metals are more anisotropic than magnesium, similar methods might well be applied to them. Ernst and Laves2 produced a double-refracting layer on magnesium alloy specimens by SuCCeSSiVe etches in solutions of perchloric acid in alcohol, magnesium perchlorate in perchloric acid and alcohol, and calcium and magnesium carbonates in water. They examined their specimens under polarized light and were able to determine the direction of the hexagonal axis in any particular grain from a measurement of the extinction behavior of that grain. The disadvantages of their technique were the complexity of the etching procedure and the explosive hazard of the perchloric acid-alcohol solutions. Results equivalent to those of Ernst and Laves were obtained in this investigation after etching specimens for 6 to 8 sec in an acetic picral solution containing 100 parts 6 pct picral, 10 parts distilled water and. 5 parts acetic acid. A. similar etch has been used by George3 in earlier metallographic

Jan 1, 1958

By Richard M. Foose

Most of the roofing granules produced in Pennsylvania are made by two companies at three plants. The Advance Industrial Supply Co. has three quarries and a mill at Gladhill Station, in southern Adams County. The Funkhouser Company is actively engaged in mining, quarrying and milling at Charmian, about one mile west of Gladhill Station, and at Delta, in southern York County. These three plants produced approximately 100,000 short tons of granules in 1943. The production of rooling granules in 1937 for the whole country was only about 500,000 tons, generally indicating the large growth of the industry since that time. The fundamentals of producing roofing granules were discussed comprehensively by G. W. Josephson in a paper before the Industrial Minerals Division in October 1943 (TP 1725, this volume page 460). The purpose of this paper is to describe the actual methods of mining the rock and milling it to make roofing granules, as practiced by the three Pennsylvania plants. Mining and Milling Funkhouser Company (Delta) The Funkhouser Company, near Delta, in southern York County, Pennsylvania, operates three joined quarries and a mine in the Peach Bottom slate. The joined quarries extend 1200 ft. in a northeast-southwest direction along the strike of the slate cleavage and are about 200 ft. .wide. The working face is about 45 ft. high. The quarrying operation is rather simple: Ingersoll-Rand Jackhamers, I-in. and 1 1/4-in., with hollow drill steel, are used to undercut the quarry face with 10-ft. holes. The face is "blown" and allowed to slump on the quarry floor. Loaded by a Marion electric shovel into trucks, the shattered rock is taken to the primary crusher 2500 ft. away. In addition to the normal quarrying operations, a drift into the northeast wall of the middle quarry was begun about 1935, and has advanced about 2000 ft. since then. Rooms have been driven at angles to the drift along choice beds of slate. The drifts and rooms have a roof more than 35 ft. high and the main drift and rooms are all more than 40 ft. wide. There is no cribbing at any place in the mine. Several of the rooms were driven upward on a 5' slope and in some of them there was stop-ing. Ingersoll-Rand Jackhamers are used, and only wet drilling is practiced. When visited in January 1940, an electric shovel was operating at the head of the drift, scooping up the slate blasted out of the working face. This, too, is trucked to the primary crusher. Some of the better quality slate is saved for making slate shingles. The primary crusher, which is a No. 30 McCulley gyratory, receives the slate from the trucks and crushes it to about a-in. size (Fig. I). This product travels by a 30-in. belt conveyor to Niagara vibrating screens with 2-in. holes. The minus a-in. product moves to a storage silo by bucket

Jan 1, 1948