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By Truman Aldrich

THE Clinton group of the Silurian holds the red or fossiliferous ore; its outcrops have been mapped by the State or U. S. Geological Survey. This group is from 100 to 500 ft. thick in Alabama. There are places where it is entirely missing (doubtless islands in the Silurian Sea). In Etowah County, in part of Greasy Cove and vicinity, the upper seam is a coral reef impregnated with the red ore; in this same county, step, faults bring up the ore in three or four separate ridges practically parallel. In Blount County and on Raccoon Mountain, the ore runs under the carboniferous rocks and outcrops in the valleys. In examining some bore holes made in drilling for oil, the writer found the Clinton group continuing under the Warrior coal field wherever the drill has gone deep enough. It demonstrates the possibility of a source for red ore not seriously thought of until lately. The following bore holes made principally for oil, given in Bulletin No. 22, Geological Survey of Alabama, show the presence of either ore or red rock, and suggest vast resources yet to be outlined and developed for ore in the future. The locations are given by number on the map. Hole No. 1 was drilled 6 miles southeast of Russellville, Franklin County, by the Woodward Oil & Gas Co. It passed through 160 ft. of Clinton, but only a small show of red ore was found at 1280-1400 feet. A test well, No. 2, drilled near Atwood, Franklin County, in section 26, township 8, range 14, penetrated the Clinton at 1608 ft. and found 38 ft. of limy red rock, also 8 ft. of some blood red ending at 1820 ft., making 46 ft. of red rock in all. It is reported that some good ore was cut through but this work was done by a churn drill. The hole was continued by diamond drill from here. At least 400 ft. of the formation was classified as Clinton.

Jan 10, 1924

By A. L. Sweetser

EXPERIENCE has shown how difficult it is to obtain information regarding laboratory-tests in connection with the chlorination-process for the extraction of gold from its ores, and I therefore present the following method, somewhat in detail, for the benefit of those who may desire to pursue research work in this field. The ore chosen was a partly-decomposed porphyry, extremely siliceous and comparatively soft, and of an average value per ton of from $25 to $26 in gold and $0.68 in silver. The chemical analysis gave : Fe2O3, 3.35; FeS, 1.5; MnO2, 0.75; ZnCO3, 4; Al2O3, 3.20; H2O, 0.7; SiO2 and insol., 83.50 per cent. The ore, first crushed to pass a 5-mesh screen, was coned and quartered until a 45-lb. sample was obtained. Samples for assay and analysis, taken from this lot by means of riffles, were crushed to pass a 100-mesh screen. The original sample was divided into 10-lb. lots, of which one was crushed to pass a 10-mesh screen; another through a 12-; the third through a 20-, .and the last through a 30-mesh screen. Because of the production of an excessive quantity of fine material it was deemed inexpedient to crush finer than 30-mesh size-a decision the wisdom of which is proved by the data in Table I., showing the increasing ratio of slimes, in proportion as the ore is crushed finer. In order to determine the percentage of fines in the sizes of mesh selected, a weighed sample of ore was taken from each mesh, and a sample from the 10-mesh lot was passed successively through 20-, 40- and 100-mesh screens, and the percentage remaining on each screen determined. This process was repeated with the 12-, 20- and 30-mesh lots, with the results given in Table I.

Sep 1, 1907

By H. E. Rorschach

Oil-field activities in Oklahoma made 1936 the best year since 1930. Approximately 2800 wells were completed, an increase of about 20 per cent over 1935. Purchasers' reports filed with the Corporation Commission showed a total of 200,240,252 bbl. of oil purchased from leases in 1936. The assembly of a complete table of the oil fields of the state was not achieved, as many of the early records of operators and pipe-line companies are not complete, and data for the older fields will perhaps never be fully tabulated. Table 1 includes all of the new fields and most of the important fields of the State of Oklahoma. The outstanding developments of the year were: the discovery of rich Wilcox-sand production in the Moore pool; the spectacular drilling campaign in the Capitol or Mansion extension in the Oklahoma City pool; the surprising extension of the Olympic pool and the Hunton lime zone in the Fitts pool; and the failure to find more Ordovician production in southern Oklahoma. Wildcat discoveries, which were on a par with 1935, resulted in the discovery of such promising pools as Billings-Wilcox, North Bethel, North Earlsboro and North Lucien. The Fitts-Upper Simpson, Edmond, Jesse, Keokuk Falls and South Burbank pools underwent considerable development. Fitts Pool.—The Fitts area in Pontotoc County was greatly extended during the year and was the leader in drilling activity in the state. The producing limits were pushed to the east and north and the development of the Hunton lime horizon was outstanding. In the Upper Simpson zone 162 wells were completed; 137 in the Hunton lime zone and 26 in the Wilcox zone. The Oil Creek zone, a sand body below the Wilcox member, was discovered by the Magnolia-Statler No. 3 well located in the 1/4. 1/4 of sec. 28-2N.-7E. Moore Pool.—The Moore pool, in Cleveland County, which was opened in 1935 by the Sinclair Prairie-Franklin Community No. 1 well, surprised the oil industry when the Sinclair Prairie-Marvel No. 1 well, on Apr. 1, 1936, discovered a rich body of Wilcox sand below the distillate

Jan 1, 1937

By Chung Yu Wang

DURING the time I was in charge, of this mine, from 1914 to 1915, I had occasion to read the interesting papers by T. T. Read and C. M. Weld about these deposits, to find how far their observations corroborated mine. To quote from the paper on "The Mineral Production and Resources of China" by T. T. Read:' "The iron ores at Tayeh lie along the contact between a marble and an intrusive body of a dark gray syenitic rock. * * * * At one place it is slightly magnetic, apparently having been partly reduced to the magnetic oxide by the action of reducing solutions, which have deposited small amounts of copper and iron sulphides along the foot wall." To quote from the paper on "The Tayeh Iron Ore Deposits"2 by C. M. Weld: "I find the orebodies described as occurring along an approximately E-W contact between horn-blende-granite and limestone. * * * * The granite is a granitoid rock consisting essentially of quartz, potash-feldspar and hornblende." These quotations show the differences of opinion entertained by two observers. My own study of these interesting deposits has been intermittent amid the manifold duties devolving upon a superintendent. General Description of the Deposits The deposits are situated to the west of the Yangtse River, being con¬nected with the river by a standard-gage railroad of 56 li (16.16 miles, 26 km.) in length, as shown in Fig. 1. The general topography of the region is of mature age, showing broad valleys with sluggishly meandering streams. These deposits are worked as two mines, named the Tieh Shan Mining Department and the Teh Tao Wan Mining Department; the former consisting of three orebodies more or less connected, named Tieh Man Kan, Sha Mau Tze and Lung Tung, and the latter consisting of Chang Pei Shan, Sze Tze Shan, Ta Shih Men, Yeh Chih Ping and Tsin Shan, also more or less connected, as shown in Fig. 2.

Jan 3, 1917

By C. R. Kuzell

IN COMPARISON with recent years 1932 has yielded much less tangible evidence of progress in copper reduction and refining. The industry has been extremely quiet, especially in the United States. Design and construction has been throttled by lack of new capital expenditures. The excess producing capacity of the whole industry and the extremely gloomy outlook for the future have made it unwise to tie up more capital except under special conditions. The plants built during the previous year have, however, been placed in operation. Older plants have been abandoned, temporarily shut down, placed on part time operating basis, or continue to operate at a low percentage of normal capacity. In the United States the Phelps Dodge Corporation at Douglas, Ariz., has completed the remodeling of the former Calumet & Arizona smelter. A new roaster and Cottrell plant chimney was completed this year. Though operations have been limited the new equipment has been found to justify all expectations. The reverberatory plant addition consists of two furnaces 26 by 107 ft. inside dimensions, with a high arch, and modern steel binding of excellent design. Natural gas fuel gives good results. One of these furnaces will treat 1000 tons of solid charge per day with a fuel consumption of approximately 3,000,000 B.t.u. per ton. The larger converters have not only yielded the expected lower costs, but have simplified operations in the converter department. One of the noticeable results is the greater cleanliness in the environment and the absence

Jan 1, 1933

By L. J. Howell, R. C. Sommer, H. H. Kellogg

WORK described herein was undertaken with the aim of determining some of the physical-chemical properties of electrolytes suitable for the electrodeposition of pure zirconium metal. In this paper the phase diagram, vapor pressure, and activities in the melt are considered. In a companion paper,' the electrolytic conductivity of some of these melts is reported. The melts studied were mixtures of NaCl and/or KC1 with ZrC1,. Chloride melts were chosen for study because 1) if the electrolyte is to be useful for industrial electrodeposition of zirconium, the chlorides will be preferred to the relatively costly bromides and iodides; 2) fluoride melts were being studied in another laboratory (Horizons Inc., Cleveland); and 3) melts containing oxygen, in any form, are unsuitable for preparation of pure zirconium, because of the great affinity of this metal for oxygen. Unlike electrodeposition from aqueous solution, the fundamental behavior of fused-salt electrolysis is poorly understood. In most cases, such basic electrochemical information as the phase diagram of the melt system, activities in the melt, conductivity, the nature of the current-carrying ions, the equilibrium electrode potentials, and the overvoltage behavior of the electrodes is unknown to the researcher who would develop a new electrodeposition process employing a fused salt. This research project was designed to supply information about some of these basic physical-chemical properties so that an intelligent choice of electrolyte for electrodeposition studies could be made. Experimental The experimental difficulties-encountered in this work result from the properties of zirconium metal and ZrC1,. ZrC1, is a solid which sublimes at 334°C. It is rapidly hydrolyzed by moist air to HC1, ZrOCl,, and ZrO,. Unusual precautions were exercised in this work to prevent hydrolysis of ZrC1, and rigidly to exclude oxygen, nitrogen, hydrogen, and carbon from the melts under study. These elements are known to react with and contaminate zirconium metal. All melts were studied in vacuum systems, i.e., in the presence of ZrC1, vapor only. Transfer of ZrC1, to or from the melts was accomplished entirely by vacuum sublimation. In this way, neither the melts nor the ingredients thereof were permitted to

Jan 1, 1958

By H. S. Munroe

The dressing-works of the St. Joseph Lead Company were destroyed by fire, February 26th, 1883. Within about four months, or on July 5th, 1883, the new mill, with a capacity of 500 tons per day, was built and in active operation. The capacity of the new mill has since been increased to 800 tons per day. The old mill was built in 1867, by Mr. C. B. Parsons, the present superintendent. It was a curious rambling old structure, which had grown with the demands of the business; a few jigs having been added in one place, a table or two in another and wings and sheds added to the main buildings, from time to time, as it was found necessary to increase the efficiency or the capacity of the mill. The old mill was, moreover, a most interesting place to the student, a perfect "museum of ore-dressing." Nearly every form of dressing apparatus known to the art had, at one time or another, found a place under its roof, jigs of many kinds, concave, convex, side-bump and stationary tables, tyes, buddles, dolly-tubs, etc., etc. The method of dressing followed in the main the lines of English practice, but with many modifications, both in the machinery and the methods of working, due to the inventive genius of Mr. Parsons. Different forms of crushing apparatus were tried, and the best method of handling the ore and the different products of

Jan 1, 1889

By Robert Baker

IT has been demonstrated in the laboratory by A. J. Phillips1 that a transformation or conversion from beta directly to alpha may take place in a brass of 61 to 62.5 per cent copper content. The completion of the transformation is dependent on a rapid rate of cooling from the all-beta field through the alpha + beta range to the alpha field. Phillips states that in a slowly cooled alloy containing 62 per cent copper and 38 per cent zinc the copper content of the beta is progressively decreased from 62 to 56 per cent by precipitation of alpha. Rapid cooling tends to prevent the separation of alpha with a copper content of more than 62 per cent by reducing to a minimum the time required for passing through the alpha + beta range. Upon crossing beyond the (alpha + beta.)/(alpha) boundary to the all-alpha region below, the material is transformed from beta to alpha. It is essential that there be no change in composition. Phillips obtained his results by quenching a 62:38 copper-zinc alloy from 850° C. in iced brine at -8° C. No reference to the occurrence of this transformation in a manufacturing process has been found in the literature. An investigation of the microstructures of a number of hot forgings made from leaded brass rods yielded one forging in which this striking conversion from beta to alpha had occurred. The purpose of this paper is to describe the transformation and certain conditions under which it may occur during the hot pressing of brass. The conversion was noted in a shape forged from a leaded brass rod, the composition of which was: Cu, 60.26 per cent; Zn, 37.86; Pb, 1.88. In this study the lead content was disregarded and the alloy was considered to be equivalent to an alloy of 61.40 per cent copper and 38.60 per cent zinc (98.12 parts = 100 parts). The possibility that the lead might obstruct or accelerate the precipitation of alpha was not studied. The lead appears as black globules in the photomicrographs and has a negligible solubility in the alloy.

Jan 1, 1931

By Chung Yu Wang

During the time I was in charge of this mine, from 1914 to 1915, I had occasion to read the interesting papers by T. T. Read and C. M. Weld about these deposits, to find how far their observations corroborated mine. To quote from the paper on "The Mineral Production and Resources of China" by T. T. Read:' "The iron ores at Tayeh * * * * lie along the contact between a marble and an intrusive body of a dark gray syenitic rock. * * * * At one place it is slightly magnetic, apparently having been partly reduced to the magnetic oxide by the action of reducing solutions, which have deposited small amounts of copper and iron sulphides along the foot wall." To quote from the paper on "The Tayeh Iron Ore Deposits"2 by C. M. Weld: "I find the orebodies described as occurring along an approximately E-W contact between hornblende-granite and limestone. * * * * The granite is a granitoid rock consisting essentially of quartz, potash-feldspar and hornblende."' These quotations show the differences of opinion entertained by two observers. My own study of these interesting deposits has been intermittent amid the manifold duties devolving upon a superintendent. General DescriptLon of the Deposits The deposits are situated to the west of the Yangtse River, being connected with the river by a standard-gage railroad of 66 li (18.16 miles, 26 km.) in length, as shown in Fig. 1. The general topography of the region is of mature age, showing broad valleys with sluggishly meandering streams. These deposits are worked as two mines, named the Tieh Shan Mining Department and the Teh Tao Wan Mining Department; the former consisting of three orebodies more or less connected, named Tieh Man Kan, Sha Mau Tze and Lung Tung, and the latter consisting of Chang Pei Shan, Sze Tze Shan, Ta Shih Men, Yeh Chih Ping and Tsin Shan, also more or less connected, as shown in Fig. 2.

Jan 1, 1918

By F. F. Hintze

Petroleum production in the Rocky Mountain district during 1929 registered a small decline from that of the previous year, conforming with a gradual decrease in the amount of oil produced during the last few years. A number of causes may be mentioned to account for this result, chiefly overproduction in other regions and the apparent desire of operators in this territory to conform to the policy of proration and retrenchment adopted by special agreement among operators in many of the fields. Unit operation has been adopted to control oil production from the Sundance sands in the Salt Creek field, Wyoming, in line with the general effort to stabilize this phase of the industry and prevent excessive drilling of new wells. Another factor which greatly retarded development in the Rocky Mountain region was the executive order of President Hoover issued in March refusing the award of new prospecting permits to future applicants and threatening cancellation of all existing permits upon which actual drilling had not been done as specified by law. Only four states in the Rocky Mountain region are important oil producers. In 1929 Wyoming led with an average daily output of 52,600 bbl., followed by Montana, with 10,730 bbl.; Colorado, with 6500 bbl., and New Mexico with 2700 bbl. daily average. These states bear the following percentage relation to total production in the Rocky Mountain district: Wyoming, 72; Montana, 15; Colorado, 9; New Mexico, 4., (Table 1.) The total average daily production was approximately 73,000 bbl. and the total production of all four states during the year was 26,534,606 bbl. This is 2.7 per cent. of the total oil production of the United States during this period. Colorado Although Colorado is not a large producer of oil and natural gas, its oil operations are widely distributed over the state. The Florence field is one of the oldest oil fields in the country, and there are good reasons for believing that the state will retain its place for many years to

Jan 1, 1930

By F. Benard

Recovery of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.l During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 165,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. Equipment Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 1/2-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 Ib. steam pressure. The solution is circulated through the steam chest by a pump of antimoniallead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1944

By Frederic Benard

Recovery of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.l During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 166,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. Equipment Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 1/2-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 Ib. steam pressure. The solution is circulated through the steam chest by a pump of antimonial lead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1943

By Frederic Benard

Recovery of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.l During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 166,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. Equipment Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 1/2-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 Ib. steam pressure. The solution is circulated through the steam chest by a pump of antimonial lead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1943

By Frederic Benard

RECOVERY of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.1 During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 165,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. EQUIPMENT Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and. arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 3-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 lb. steam pressure. The solution is circulated through the steam chest by a pump of antimonial lead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1938

By David Keys

THE object of this investigation was to determine with a vertical magnetic variometer the extent of the titaniferous ore deposit that occurs not far from Ivry in Terrebonne County, Quebec, about 70 miles north of Montreal. The Ivry mine, on lots 37 and 38 of range V, Beres-ford township, Quebec, is one of the largest and most accessible to transportation of the deposits of ilmenite in Quebec. The ore consists of an aggregate of ilmenite anhedra serving as host for numerous fine plaques of hematite. No magnetite is known from any occurrence near this lot, and in this way the deposit differs from many others that contain a large percentage of magnetite with the ilmenite. The deposit at Ivry thus has much lower magnetic susceptibility than those containing abun-dant magnetite, and a sensitive magnetometer was necessary for the work, although a body of magnetite with ilmenite about a mile from the Ivry mine was successfully prospected with a dip needle. The principal orebody is exposed in a quarry known as the Ivry mine, from which about 16,000 tons of ore have been shipped. Small exposures of ilmenite isolated by drift serve to show the presence at the surface of some of the bodies indicated by the magnetometer,- but most of the hill is covered with glacial till and second growth hardwood. At the lower levels the till gives place to fluvioglacial sands and gravels from which the forest has been cleared. The increasing thickness of the sand and gravel as the hill descends makes the tracing outward of the deposits from the rocky knob of anorthosite a difficult matter. Within the orebodies too, some masses of anorthosite persist, which may account for some local irregularities. Fig. 1 is a photomicrograph, taken by reflected light, of a typical specimen of the ore. The dark patches are hematite and the light parts are ilmenite. No trace of magnetite was found. Fig. 2 is a photo-micrograph of a thin section of the country rock showing the texture of the anorthosite. The mean of four analyses quoted by Robinson1 is: titanium, 19.26 per cent; iron 45:41 per cent.

Jan 1, 1936

By A. S. Callen

These iron mines of Spain are located on the mountain ridge forming the boundary between the Teruel and Guadalajara provinces, called Sierra Menera. They form a property of 25 mines extending over an area of 1,677 hectares (4,140 acres) situated at a height varying from 1,200 m. (3,940 ft.) to 1,500 m. (4,920 ft.) above sea level. The deposit follows the direction north to south; huge masses of ore are being found both on the slopes and at the summit of the Sierra. The ore occurs among quartzites and magnesite limestone, in some places overlaid by quartzite 15 m. (50 ft.) thick; in some others (and this is more general) the ore is overlaid by earth and boulders of quartzite origin; this layer is about 8 m. (26 ft.) thick. The ore beds occupy the geological horizon of the Superior Trias or Muschelkask, which are here in direct contact with the Silurian quartzites. The lime-stones have been more or less transformed. There is ample evidence to show that these mines were worked in very ancient times—objects and tools employed in mining by the ancient Romans and Arabs are to be found plentifully in old workinigs which extend down into the deposits. It has been estimated that more than 10,000,000 tons of ore were mined in the old days in this district and carried to the primitive forges in the vicinity where iron of much renown in Spain was extracted. Remains of more than 20 of these forges are found in the neighborhood of Sierra Menera and are usually situated near waterfalls and forests. Much investigation has been carried on for the purpose of determining the quantity of ore to be found in these mines, but no exact calculations can be made at present. When the investigation is completed it will surely be found that the deposit contains a much larger quantity than the 100,000,000 tons indicated by the present workings. The mines are now worked as open quarries and this method can and will be followed for a long time, probably until the deposit is worked out. Figs. 1 and 2 give some idea of the quarries in operation and the reserves, the iron-ore stocks, screening installation and general arrangement. From these quarries 1,000,000 tons can be mined annually (987,000

Jan 1, 1916

By Shiou-Chuan Sun

THE fact that coals of different ranks and even of the same rank differ greatly in their amenability to iroth flotation is well known. In recognition of the need for an explanation of this phenomenon, two hypotheses have been suggested. Wilkinsl reported that the floatability of coals increased with an increase of the carbon content or rank. This postulate is handicapped by the fact that bituminous coals that possess moderate carbon contents are actually more floatable than anthracite coals that have high carbon contents, as shown in columns 6 and 9 of Table I. Taggart and his associates' implied that the difference of floatability between bituminous and anthracite coal was caused by the variation of carbon-hydrogen ratio. This is not applicable to the relative floatability of other coals and carbons. For example, column 11 of Table I shows that the carbon-hydrogen ratios of low-floating lignitic coal and non-floating animal charcoal are not only smaller than the moderate-floating anthracite coal, but are also similar to the high-floating bituminous coal. Furthermore, according to this hypothesis, high temperature coke-A (464), Ceylon graphite (1238), and lamp-black (357), all possessing extremely high carbon-hydrogen ratios, should be less floatable than other substances having much lower carbon-hydrogen ratios such as high volatile-B bituminous coal (11.9 to 22), anthracite coal (35.7 to 60.5), lignitic coal (15.6 to 33.6), and charcoal (13 to 26.2). However the former group is actually more floatable than the latter group. In this paper, a surface components hypothesis is Proposed to explain the different floatabilities of coals, carbons, and hydrocarbon minerals. The validity of the hypothesis is experimentally supported by the actual floatability, natural floatability, wettability, and adsorbability for neutral oils of coals, carbons, and hydrocarbon minerals tested. The combustible recovery of the flotation results, as used in this paper. was calculated from Eq. 1: P (100-Ep) 100 RWCP Rc= [1] F (100-E,) C, where R, is the percent combustible recovery; F and P are, respectively, the weight of feed and the weight of concentrate or product; E, and Ep are, respectively, the total percent of ash plus moisture in feed and in concentrate; Ru. is the percent weight recovery: and C, and C, are, respectively, the percent of combustible in feed and in concentrate. Except for ash and moisture content, all chemical components of a coal are assumed combustible. The experimental work included studies on flotation, ultimate and proximate analyses, contact angle tests, extractions of bitumen-A with benzene, adsorptions for liquid hydrocarbons, and wetting tests. Most of the flotation experiments were performed in a laboratory Fagergren machine; others were tested in a small Denver machine. The solid feed for the former was 300 g and for the latter was 30 g. The solid materials used for flotation were crushed to —48 mesh. After the mineral pulp in the flotation cell was agitated for 6 min and the pH was adjusted to 7.5 & 0.2 with sodium hydroxide or hydrochloric acid, a petroleum light oil having a viscosity of 5.73 centipoises at 77 °F was added and conditioned for 2 min. Finally, pine oil was introduced and the froth was collected for exactly 3 min. The weight ratio of petroleum light oil to pine oil was kept constant at 1.5 to 1. Tap water was used for all flotation tests. Contact angles were measured with a captive bubble machine. For each coal sample, three specimens were mounted in transoptic mounts and polished with levigated alumina, first on a sheet glass, then on a cloth-covered metal polishing wheel. The polished specimen was first washed with distilled water and wiped thoroughly on a cleaned linen pad, then transferred into the pyrex cell of the captive bubble machine and conditioned for 6 min., and finally measured for contact angles at three or more points. Except where otherwise stated, the induction time for each measurement was 1 min. The contact angle representing each material was obtained by averaging the measurements of three specimens. The linen pad was first washed with warm distilled water, then boiled 30 min in a 2N sodium hydroxide solution, and finally washed with distilled water until no trace of sodium hydroxide could be detected in the decanted solution. The cleaned linen pad was stored under distilled water. Immediately before using, the pad was rewashed and transferred into a clean pyrex petri dish partly filled with distilled water. The glassware and rubber gloves used were cleaned by soaking in sulphuric acid-potassium dichromate cleaning solution, followed by rinsing with distilled water. The polished specimens were handled only by glass forceps. The ultimate and proximate analyses were made in accordance with the ASTM standard procedures for coal and coke. The extractable bitumen-A was determined by weighing 1 g of —100 mesh sample and placing it in a desiccated and weighed ASTM aluminum-extraction thimble. The thimble was placed in condenser hooks and inserted into an extraction flask containing 100 cu cm of benzene. The flask was heated and the benzene vapor was condensed by water coils. At the end of 24 hr of percolation, the thimble was removed, desiccated, and weighed. Loss in weight of sample was taken as bitumen-A and calculated to dry and ash-free basis.

Jan 1, 1955

By Harry C. Gatos, Frank J. Bachner

It was shown through high-pressure experiments that tin loss by volatilizatim is necessary for the degrada-tion of the superconducting transition temperature of Nb,Sn associated with high-temperature annealing. Crystallochemical analysis of the degraded Nb3Sn showed that it constitutes a new phase with ordered niobium-site vacancies, created by the migration of niobium atoms to vaccnt tin sites. This new phase was found to form when 4 pct Nb-site vacancies were present. It has a transition temperature of 6'K and a lattice parameter of 5.283A. A similar degradation effect was observed in Nb,Al. Its superconducting transition temperature dropped from 16.5" to 8" K following a high-temperature annealing. The superconducting temperature degradation in these 0-tungsten structure compounds is attributed to the disruption of the interchain d bonding by the periodic interruption of the niobium atom chains. By annealing the degraded Nb, Sn at 1000 C in nitrogen its normal superconducting behavior is restored most likely due to the incorporation of nitrogen atoms causing the elimination of the ordered vacancies. HANAK et al.' have observed low superconducting transition-temperature values (T, - 9"K) in some NbsSn samples deposited from the vapor phase. They attributed such low T, values to disorder in the 0-tung-sten structure. Much lower T values (down to 5.6"K) were reported by Reed et al.zC for NbsSn samples annealed at high temperatures. These authors also attributed this degradation effect to disorder (random occupation of the A and B sites by niobium and tin) but pointed out that such disorder could be brought about (by high-temperature treatment) only in samples containing niobium in excess of the stoichiometric composition NbsSn. Both groups reported that the normal superconductivity behavior could be rever-sibly restored by appropriate heat treatment. Courtney et al., also found that degradation in NbsSn requires excess niobium brought about by the loss of tin during the treatment. However, these investigators proposed that the degradation is due to niobium-site vacancies resulting from the migration of the niobium atoms to the vacated tin atom sites. They did not consider the reversibility of the effect. The present study attempts to establish the nature of the above degradation phenomenon. EXPERIMENTAL PROCEDURES All compounds prepared for this investigation were made from the powders or filings of the elements which were intimately mixed, cold-pressed into a cylindrical pellet at approximately 50,000 lb per sq in., and then submitted to the desired heat treatment. The samples annealed under high pressure were placed in a MgO sample container which was mounted in a pyrophyllite tetrahedron designed for a tetra-hedral-anvil press. Details of the experimental arrangement are given elsewhere. This setup allowed heating at 1800°C or above under pressures in excess of 30kbars for 3 hr. The samples annealed in a vacuum were prepared in a high-temperature vacuum furnace which could reach temperatures up to 2400°C under a pressure of 2 x lo-' Torr. For annealing in a reactive atmosphere, a quartz tube was placed in a clamshell furnace and the desired gas ambient passed through the tube. Lattice parameters were determined using a Debye-Scherer 114.6-mm camera. Cohen's method, programmed for the IBM 7094 computer, was used to calculate the lattice parameter from the measured d spacings. X-ray integrated intensity measurements were made on several samples. These samples were ground to -400 mesh and the powder mixed with a solution of collodion in amyl acetate. The mixture was poured into a depression milled in a bakelite disc. When the mixture dried, the surface of the disc was ground flat leaving a diffraction surface defined by the face of the disc. The disc was mounted in a Philips rotating specimen holder which allowed the rotation of the sample in the plane of the diffraction surface and the integrated intensity measured using a scintillation counter and a pulse-height analysis sys-tem. The superconducting transition temperatures were determined by means of self-inductance techniques.' EXPERIMENTAL RESULTS AND DISCUSSION The Role of Tin Loss in the Degradation of Super-conductivity. The loss of tin during high-temperature annealing can be effectively suppressed by annealing under high hydrostatic pressures. Accordingly, a series of experiments were performed under pressures of approximately 30kbars. This pressure was the minimum under which high-temperature experiments could be safely performed in the particular pressure apparatus employed. Experiments were also designed to test high-pressure effects on the superconductivity behavior of NbJSn. The results of the high-pressure annealing experi-ments are summarized in Table I. All samples were prepared as described earlier. They were reacted and homogenized at 1000°C for 24 hr under argon at-

Jan 1, 1967

By L. Bombardieri, H. F. Mills

Iron King mine, producing gold-silver-lead-zinc-ore, is 10 miles east of Prescott, Ariz. At present the 1806 level is being developed. The echelon pat tern of ore deposit continues at depth but is less pronounced, and the orebody is now more or less continuous over 2600 ft of strike length, with widths 5 ft to as high as 26 ft where overlapping of lenses occurs in one section of the mine. Better continuity of ore at depth has encouraged systematic mining and improved plant facilities to offset higher operating costs. With favorable persistence of ore at depth, the three-compartment No. 6 hoisting shaft appeared inadequate to handle increased tonnage from greater depths, and in 1952, a four-compartment steel and concrete shaft was started. This is now at a depth of 1906 ft, and shaft pockets and loading cartridges are being installed on the 1806 level. Ore from the new shaft, hoisted in 5 ½ -ton Jeto bottom dump skips, is dumped into a 500-ton shaft bin, from which it is fed to a 16x30-in. gyratory crusher and conveyed 415 ft through an undersurface concrete gallery to the secondary crusher and conveying system supplying the 900-ton mill. Lead, zinc, and pyrite concentrates are floated, and the flotation tailings are cyanided after desliming. Waste from the new shaft is dumped into a 250-ton surge bin, fed from this bin to a 24-in. conveyor, and discharged into the glory hole above the block cave. The new shaft is served by a double-drum 400-hp hoist used for ore and waste; the No. 6 shaft conveys men and material.

Jul 1, 1956

By Lawrence Adler

For openings in bedded rocks, analyzed by simple beam theory, it has been shown that roof loads can be shifted from one support to another.' This transfer is effected by controlling the relative deflection of adjacent supports. If this action is used to reduce loads in the props or bolts and increase them in the ribs or pillars, it could be productive of economies averaging 30 pct. Such savings can be realized by: 1) using smaller artifical supports such as props and bolts, and 2) increasing loads in the rib to induce eventual failure for longwall caving. Since the rib is relatively load-insensitive, it provides a natural load sink. However, caution must be used in applying such permissive deflections, for while the supports are being handled properly, the stresses in the roof itself are very sensitive to such manipulations.'

Jan 5, 1960