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By Alton B. Cook, G. B. Shea

"INTRODUCTION In February 1945, Captain (now Commodore) W. G. Greeman, U. S. N., Director, Naval Petroleum and Oil 3hale Reserves, requested the Bureau of Mines to assist the Navy in its wartime development of Naval Petroleum Reserve No. 1, Elk Hills field, Calif., to assure adequate supplies of petroleum products in the Pacific theatre. Unit Operation 4/,engineers desired pressure volume-temperature and viscosity data on the reservoir oil in the shallow oil zone to augment data previously obtained for the purpose of calculating reservoir performance and oil reserves. Accordingly, arrangements were approved by the Operating Committee far, the Bureau of Mines to proceed with a program of field sampling and laboratory determinations designed to obtain the desired information.To carry out the assignment, the Bureau transferred the necessary person¬nel, subsurface pressure, temperature, and sampling instruments, and laboratory equipment for analyzing subsurface oil samples from the Petroleum Experiment Station, Bartlesville, Okla., and the San Francisco, Calif., office and set up a temporary field headquarters in the Elk Hills. The program of work as out-lined by Unit Operation required the 6 months period March-August 1945 to complete during which time individual reports comprising data on pressure-volume-temperature relationships and reservoir oil viscosities as determined on subsurface oil samples and recombined oil and gas samples for 5 selected wells were submitted to Unit Operation.This report is a summary compilation of the data contained in the original reports supplemented by correlations of some of the physical properties of the reservoir oil with the A.P.I. gravities of the produced oil. The report also includes material-balance calculations relative to one of the oil horizons in the shallow zone. The Bureau of Mines believes that publication of the results of these analyses is a worthwhile contribution to the petroleum literature and of particular interest to the California industry."

Apr 1, 1947

By J. Girard-Dwyer, T. Camm

Direct costs such as medical, legal, administrative, and worker’s compensation costs, property damage, lost earnings, and lost benefits are typically used to compute the economic impacts of occupational injuries. However, there are also a number of less obvious, indirect costs that substantially contribute to the overall loss costs. In fact, for every $1 of direct costs an estimated $3 to $5 of indirect costs are also incurred. This paper presents a systems approach that incorporates engineering, economics, psychology, and sociology in order to evaluate the total value of investments in safety. By studying the interrelated system comprised of the injured worker, their family and coworkers, as well as the organizational structure that was the setting for the incident, a methodology can be developed that will more accurately capture the true costs of mine injuries.

By L. E. Geyer

"The following list gives the title and author of various publications of the Ceramic Experiment Station, Columbus. Ohio, of the Bureau of mines, together with other ceramic publications of the bureau, which have been published in technical journals and by cooperating agencies. The list also includes the publications on ceramics which have been issued as bulletins, technical papers, or mimeograph Report of Investigations of the bureau.Papers Published in the Technical Press.The Effect of some Electrolytes on the Properties of Clays. Schurecht, H.G. Jour. Am. Cer. Soc., Vol. 1, #3, March, 1918.A Pycnometer Operated as a Volumeter. Schurecht, H.G. Jour. Am. Cer. Soc.,Vol. 1, #8, August, 1918.The Properties of some Ohio and Pennsylvania Stoneware Clays. Schurecht,H.G. Jour. Am. Cer. Soc., Vol. 1, #4, April, 1918.The Fusibility of Graphite Ash and its Influence on the Refractoriness of Bond Clay. Booze, M.C. Jour. Am. Cer. Soc., Vol. 2, #1. Jan., 1919.Behavior under Brass Foundry practice of Crucibles containing Ceylon, Canadian and Alabama Graphites. Stull, R.T. Jour. Am. Cer. Soc., Vol. 2, #3. March, 1919."

Oct 1, 1924

By S. J. Schatzel, W. P. Diamond

High methane emissions originating from the active face areas and from the fractured formations overlying and underlying the mined coalbed can adversely affect both safety and productivity in underground coal mines. Since ventilation alone may not be sufficient to control the methane levels in the longwall mining environment, gob gas ventholes have become a standard supplementary methane control option in many mines. As mines progress into deeper and gassier coalbeds, or as longwall panel size increases, ventilation and gob gas ventholes together may not be sufficient to maintain methane levels within statutory limits. To decrease the risk associated with methane emissions under these circumstances, in-seam horizontal methane drainage is often used to reduce the gas content of the coalbed prior to mining. Horizontal methane drainage borehole completion designs, drilling strategies, and degasification lead times may need to be adjusted for site-specific conditions due to mine design, geology, and the gas content of the coalbed. This study investigates different horizontal methane drainage borehole patterns, borehole lengths, and degasification times prior to and during panel extraction to evaluate their effectiveness in reducing methane emissions using a "dynamic" 3D reservoir modeling of a 38 1-m wide longwall panel operating in the Pittsburgh coalbed. Results of this study showed that dual and tri-lateral boreholes are more effective in decreasing emissions and in shielding the entries compared to fewer shorter, cross-panel, horizontal boreholes parallel to the longwall face. Modeling results showed that after 12 months of pre-mining methane drainage, the average longwall face emission rates can be reduced by as much as 10.3 m3/min and 6.8 m3/min using tri- and dual-lateral boreholes, respectively. It was also shown that if pre-mining methane drainage time is short, it is important to continue methane drainage during the panel extraction to maximize reductions in longwall face emissions since additional face emission reductions achieved during this period can be comparable to pre-mining degasification.

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions2 issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor; if it is not, a price adjustment is made, Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1971

By Arthur Metcalfe, Edward Thomas, A. J. Barry

"Early in 1947 the Bureau of Mines became interested in adapting suspension roof support to coal mining 5/ as a possible means of reducing the high rate of accidents from falls of roof. For a time the program made little progress be¬cause of the shortage of steel products after the end of World War II, but during the past 8 months this restriction has eased, and as of May 1, 1949, 114 mines had either started experimental work or had ordered materials and equip¬ment in anticipation of trial installations. It is estimated that 30 linear miles of roof in underground passageways have been secured by this method in recent months, and no lost-time roof-fall accident has been reported in these areas up to that date.Many coal-mining companies in widely separated localities have cooperated in making experimental installations. In very few instances are these companies entirely satisfied that they have arrived at the best solution in determining the most efficient adaptation to suit their particular conditions. Moreover, new ideas and modifications of the basic principle are constantly being brought to light and are being tested. Available test data is far from complete, and it is conceivable that some new idea will be developed to alter the present concept of proper technique; therefore, this progress report does not attempt to answer all questions that might arise in connection with this method of roof support; it simply recounts the experience acquired to date. Consequently, few references to costs are made. Up-to-date quotations on material and equipment used in suspension roof-support installations may be obtained from numerous mine-supply companies.The authors gratefully acknowledge the cooperation of mining companies whose personnel made possible collection of the information contained in this circular: Bethlehem Collieries Corp., Barrackville, W. Va.; Berwind-White Coal Mining Co., Windber, Pa.; Consolidation Coal Co., (Ky.); Jenkins, Ky.; Consolidation Coal Co. (W. Va.), Fairmont, W.Va.; Clinchfield Coal Corp., Dante, Va.; Consolidated Coal Co., St. Louis, Mo.; Hanna Coal Co., St. Clairsville, Ohio; Missouri Portland Cement Co., Sugar Creek, Mo.; Pocahontas Fuel Corp., Pocahontas, Va.; Reppert Coal Co., Dola, W. Va.; St. Joseph Lead Co., Bonne Terre, Mo.; and Tennessee Coal, Iron, & Railroad Co., Birmingham, Ala.The fundamental theory of suspension roof supports is not new; in fact, its application in the construction of beams predates mining itself. The basic principle involved is the reinforcement of roof rock with steel rods inserted in the roof and anchored therein at points where the rock is least likely to be affected by stresses resulting from mining. Such roof supports have been used in mines for many years in widely separated localities. The St. Joseph Lead Co., operating in southeastern Missouri, apparently was the first large mining company to prove the practicability of the principle by applying it in a systematic manner for securing roof for more than 20 years (fig. 1)."

Sep 1, 1949

By H. R. O'Brien

"During the past year, the Pittsburgh experiment station of the Bureau of Mines has been investigating methods for the quantitative estimation of carbon monoxide in blood. This work was necessary because reliable methods of analysis are of the greatest importance in the bureau's research work on prevention and treatment of carbon monoxide poisoning among workers in mines and metallurgical plants. Two of the methods considered involve color comparisons. In one of these methods, differences in tint can be noted fairly readily, while in the other, they are much more difficult to detect. The latter, however, is otherwise considerably simpler. It was decided, therefore, in studying the possibilities of this second method, to use the most sensitive eyes in the laboratory force.Preliminary trials.The method under investigation was the Haldane carmine determination of carbon monoxide in blood. The plain oxyhamoglobin of the blood in dilute solution is a pale straw color, when exposed to carbon monoxide it becomes a cherry pink. In the analysis dilute indigo carmine is added to oxyhsmoglobin until the solution matches in tint the carbon monoxide hemoglobin. The eye wanted, then, was the one most sensitive to faint pinks. But just how to select the analyst was not clear At first the Williams test scale, used in the Navy, was considered, but on con¬sultation with Dr. L. L. Thurston, bead of the Department of Psychology at Carnegie Institute of Technology, the following procedure was adopted.Instead of standard tests made up of all colors, only those occurring in the analysis were used. Solutions were prepared of the two hemoglobins, from which twenty-four different pairs were made up and placed in test tubes like those expected to be used in the analysis. One of each pair differed from the other in percentage of carbon monoxide hemoglobin by amounts varying from 2-1/2 per cent to 20 per cent. Each pair was compared in a box built in our own shop. This was 20 inches long and 5 inches square in cross section. One end was covered with ground glass. Just inside this glass cover were provided two slots, each the width of the test tubes used. The tubes to be compared were dropped into these slots through two holes in the top of the box. The device was placed before a window away from the sun, and so arranged that the light conditions were the same on each slit or opening. The person to be tested was seated before the box, and as the two tubes were placed before him side by side, he marked whether A (left) or B (right) contained the more cherry pink. This procedure was continued till he had compared all the pairs."

Jul 1, 1921

By A. R. T. Denues, A. P. Rowles

"INTRODUCTION Summarized data developed by J. E. Crawshaw and E.J. Murphy, 4/of the Explosives Division of the Bureau of Mines, suggesting marked variations in oxygen condition in three permissible explosives, have been reported 5/. Such variation is of interest in other work, it having been shown, for example, that the oxygen condition may have marked effect upon the products 3/ and the propulsive strength 7/ of explosives. It seemed that a more detailed presentation and more usual statistical analysis of these data might be of considerable general interest and not complemented in the literature.This report presents both the original data developed by Crawshaw and Murphy and the results of a simplified but seemingly acceptable statistical analysis of these data. The logical ground for this analysis might seem somewhat questionable because of the lack of systematic information concerning the extent of errors in the analytical procedure but the data show that there are several cogent and seemingly unequivocal indications of real heterogeneity in the explosives."

Jun 1, 1942

By John E. Pahlman

The Bureau of Mines conducted column-leaching tests on 25 domestic Mn ores to determine the feasibility of extracting Mn by in situ or heap leaching with dissolved sulfur dioxide (S02) solutions. The ores tested were obtained from deposits in Arizona, Arkansas, California, Colorado. Maine, Minnesota, Nevada, and South Dakota. Dissolved S02 was found to be effective for leaching Mn; extractions greater than 90 pct were obtained with solution application rates of 1 mL/min from uncalcined, minus 2.5-plus 1.3-cm ore pieces. Leaching these ores with solutions containing only 5-wt-pct S02 and no added H2S04 resulted in Mn being selectively extracted over Fe except when Fe was present as goethite or siderite. Ca solubilization was inhibited by controlling the solution application rate (1 mL/min). The rate of leaching was found to be principally dependent upon the rate at which the leaching solution can penetrate the ore, since the solubilization of Mn upon contact with S02 was observed to be rapid. Despite low water permeabilities of the ores (as low as 10-2 to 10-4 darcy). greater than 90 pct of the Mn was extracted from even the largest ore pieces tested (approximately 10 cm in diameter). It appears, therefore. that leaching Mn opens up the pores, allowing penetration of the leach solution into the ore pieces.

Jan 1, 1988

By Robert P. Apa

Energy Incorporated has prepared this final report presenting the results obtained from the program for extracting alumina from anthracite culm along with the recovery of energy. This work has been accomplished under the auspices of the U.S. Bureau of Mines with technical coordination through the bureau's Reno, Nevada facility. The objective of this program was to develop a process to recover alumina and energy from Northeastern Pennsylvania anthracite mining waste. The program included Identification of sufficient resources to support a commercial facility, identification of the operating parameters which maximize alumina and energy recovery, the development of a conceptual process design, preparation of material and energy balance(s), and the performance of a system economical analysis. The program was conducted in three major phases. In the first phase the program concentrated on selecting several anthracite culm banks capable of supporting a commercial alumina producing facility. The chosen banks were then sampled and analyzed leading to the selection of two banks which were chosen far testing. The Harry E. and Eckley culm banks were the ones selected. Material from these banks was tested in Energy Incorporated?s Idaho Falls, Idaho testing facility. Parametric testing was accomplished in an eight-inch-diameter fluidized bed test facility. The test program consisted of twelve separate tests. After critical operating parameters were determined, the second phase started: process development in EI's 18-inch fluidized bed test facility. Three material and energy balance tests were completed in this facility. Following these tests a 72-hour demonstration test was performed. The data acquired from these tests were used in the last phase: the process conceptual design and economic analysis. The design basis was a commercial scale facility capable of producing 500,000 tons of alumina per year for 15 years. Based on the test program, It is technically feasible to build and operate such a plant today. The facility would produce, along with the alumina, 81.5 MWe of electricity for outside consumption. A preliminary rate of return indicates that the plant is not feasible with today's economic conditions. An increase in the market price of either the alumina or the electricity is required to provide an attractive rate of return for the facility.

Jan 1, 1982

By Tracy. L. D.

"Since the introduction of pulverized coal as a substitute fuel for natural gas in the various types of heating furnaces used, in steel mills, a number of fires and explosions have occurred, resulting in the loss of life and property.As one of the primary functions of the Bureau of Mines is to conduct investigations in the utilization of mineral substances with a view to increasing safety in the use thereof, it was deemed advisable to investigate the hazards involved in the industrial use of pulverized coal and, if possible, to devise methods of preventing future accidents arising therefrom. The knowledge of the explosive qualities of coal dust which the Bureau has gained in studies affecting dust explosions in coal mines was of material assistance in these investigations.Several plants were visited in which either fires or explosions had occurred, and data obtained as to the probable cause of the accidents.There was found to exist, among some of those employed about the furnaces, a lack of knowledge of the explosive and inflammable qualities of powdered coal.A small stream of pulverized coal leaking down from a defective joint in a coal transport line did not attract much attention, whereas, had a leak in a natural gas line occurred -wider similar circumstances, no doubt it would have had immediate attention.As a matter of fact, if by any means the duet cloud should come in contact with an open flame or hot metal, the effects would be as disastrous as if it had been gas.This is exceedingly well illustrated by an accident which came to the writer's attention. In the system used at this particular plant, the pulverized coal is transported to the furnace through compressed-air lines. The fuel is fed from a storage bin to a blowing tank in quantities as desired, after which compressed air is admitted and the powdered coal blown to the furnaces. At the time of the accident some repairs were being made to the tank, and it was supposed that the air pressure had been entirely released as the pressure gage stood at zero. There was, however, one or two pounds air pressure remaining and when one of the connections was taken off, a cloud of dust was blown across the room, 30 or 40 feet towards the drier furnace where it came in contact with some live coals. Immediately the entire room was filled with flame which rolled back and forth over a specs 50 feet or so in length."

Apr 1, 1921

By Albert E. Long

To date the commercial diamond bit setters have been principally interested in the speed with which they could produce a sharp, fast-cutting bit. Thus, a premium has been placed on setters who combine a high degree of manual dexterity with the ability quickly to select the Sharp points and edges of the diamonds and set them in the mold without lost motion. The premium on speed does not allow the setters the time, nor are they trained, to consider also the crystallographic structures of the diamonds which are the clues indicating the harder and more suitable working surfaces. Since early fall of 1949, the Bureau of Mines has been conducting a long-range series of experiments in which drill bort have been oriented in diamond bits in an effort to determine the effects and economic practicability of utilizing the hardest surfaces of the diamond crystal structure. The preliminary experiments completed to date indicate that a substantial saving in diamonds may be affected by using the harder areas of the diamonds as working surfaces in the crown of diamond bits. The experimental work is being conducted by the Bureau of Mines in the laboratories and full-scale mine of the Mining Research Branch, Minerals Technology Division, Region VIII, of the U. S. Bureau of Mines at the Mount Weather Station, Bluemont, Va.

Jan 1, 1951

By Edward A. McClatchie

A novel nondispersive electro-optical gas analyzer has been designed, fabricated and tested. The instrument is based on a pressure modulated absorption technique. Key features of this new gas analyzer technique include long-term zero and calibration stability. The technique was investigated for the gases carbon dioxide (CO2), carbon monoxide (CO), methane (CH4) and nitrogen dioxide (NO2). The delivered analyzer was capable of measuring the three species CO, CO2 and NO2. It is a compact (300 cu in) package, is battery powered and weighs 15 lbs. Some thirty readings of each gas may be made on a single battery charge.

Jan 1, 1980

By Clyde E. Eilliams

In recent ye.ars much intere,t has been centered on the possibility of pro­ducing alumina from clq, a.nd proposed methods tor the recove:r,v of alumina are appearing constantly in parent lit,erature, As a good· grade of clay contains from 30 t<> 40 per cent of al"WDina, the prospect of tecovering it is alluring, al though obviously ditfieul t. A patent typical of m projected thermal processes is that 0£ Paul Migu.et, (U, S, Patent No, l,376,563) entitled nprocess for the preparation of pure alkaline alu:ninates.'' Re proposes to prepare alkaline a.luminate by fusing clay, lime, and acrap iron with a reducing aget in the electric furnAce, thereby reducing the silica a.r.d formin1s calcium alumina.te and ferrostlicon, The calcium aluminate, being lighter, would. float on top substantially free from foreign oxides, It could. then be tapped ott, cooledf ana later crushed and leached with aodium carbonate solution to torm, by double decomposition, sodium aluminate, and calcium carbonte. The fonMr is soluble and yields readily aluminum hydroxicie. 'l'he ferrosilicon wo'Uld be r,covered as such and sold at a profit.

Aug 1, 1922

By K. L. Paciorek

The aim of this program was to develop a reliable and meaning-ful basis for assessing certain safety aspects, namely fire and, in particular, toxicity hazards of articles employed in underground coal mining operations. The present investigation was concentrated on the thermal oxidative degradation of representative hydraulic fluids. To achieve this goal all products formed on thermal oxidative degradation of the fluids studied were analyzed, identified I and the amount of each individual species present was determined quantitatively on a weight of product per weight of material basis. The weight/weight data thus obtained can then be factorized to reflect the relative toxicity of each individual species present, using for example the Threshold Limit Values adopted by the American Conference of Governmental and Industrial Hygienists, whereby an overall "toxicity index" can be arrived at which makes it possible to compare the different fluids and/or classes of fluids in a quantitative manner insofar as their toxicity is concerned.

Jan 1, 1976

By R. August Heindl

A process for recovering manganese from open-hearth steel-plant slags was investigated. The proposed method of accomplishing this is indicated by the flow diagram in figure 1. Mixtures of open-hearth, steel-plant flush slags and limestone, so proportioned as to have molar [CaO -3P205] ratios of approximately 2, were fired at approximately 2,400° F. in an oxidizing atmosphere and then cooled slowly. This treatment produced a clinker consisting principally of two solid phases comprised of (1) various combinations of the oxides of manganese, iron, aluminum, and magnesium, probably in spinel complexes, and (2) a dicalcium silicate phase, which contains the phosphorus. Reduction of these clinkers with hydrogen or with gaseous mixtures containing CO, CH4, and other hydrocarbons at about 1,300° F. formed manganous oxide as well as varying amounts of ferrous oxide and iron. Carbon monoxide and mixtures of hydrogen and carbon monoxide effectively reduced the clinkers but also gave higher proportions of soluble iron when the manganese was extracted from the reduced clinkers by leaching at about 80° F. with ammonium carbonate solutions containing 26 to 28 percent ammonia and 15 to 26 percent carbon dioxide. It is believed that the manganese is in solution as an ammonia-manganese complex. Concentrations of about 90 grams of manganese per liter were obtained by batch countercurrent procedures. By distilling 50 percent of the ammonia, the ammonia-manganese complex was decomposed, and approximately 90 percent of the manganese was precipitated as the carbonate with the simultaneous precipitation of 15 to 30 percent of the iron, the larger amounts of iron precipitating in the continuous tests. The manganese-iron ratio in the product could be increased either by recycling more manganese from the distillation to the extraction or by aerating the liquor to purge it of iron before, rather than after, the distillation step. Calcination of the pelletized manganese carbonate in an oxidizing stmosphere at 2,000° F. or above gave a final product, Mn304, resistant to crushing and apparently possessing the other physical properties essential in a ferromanganese blast-furnace feed.

Jan 1, 1955

By Lathrop E. Roberts

The opinion is general among smelter operators that magnetite formed in the converter and reverberatory furnace has much to do with the loss of copper in the slag. Its action appears to be due in part to its relatively high infusibility, chemical stability, and specific gravity, as a result of Which it tends to form a layer of highly viscous "magnetite mush" between slag and matte. Particles of matte which might otherwise settle out of the slag are unable to pass through this layer. Maier and Van Arsdele have shown that the inclusion of grills of matte in the slag is also at tires very probably due to chemical reaction between magnetite and the constituents of the matte. In smelter control and in any laboratory study of slats the determination of magnetite is therefore a matter of some importance. The difficulties in the ray of making such a determination with any accuracy are rather obvious. Iron may occur in slag as ferric oxide, magnetite, various intermediate oxides, sulphides, silicates, as free metal, and in solid solution of several of these substances. Even if only the total iron content is to be determined, accuracy can be obtained only by painstaking and time-consuming separations from interfering elements. The determination of ferrous, ferric, and free iron in the presence of each other is a difficult matter under the most favorable conditions, and when present in a slag the difficulties are increased by the refractory nature of the sample, by the presence of sulphides, and by such elements as vanadium and molybdenum.

Jan 1, 1931

By Lathrop E. Roberts

[The opinion is general among smelter operators that magnetite formed in the converter and reverberatory furnace has much to do with the loss of copper in the slag. Its action appears to be due in part to its relatively high infusibility, chemical stability, and specific gravity, as a result of which it tends to fern a layer of highly viscous. "magnetite mush" between slag and matte. Particles of matte which might otherwise settle out of the slag are unable to pass through this layer. Maier and, Van Arsdale4 have shorn that the inclusion of prills of matte in the slag is also at times very probably due to chemical reaction between magnetite and the constituents of the matte. In smelter control and in envy laboratory study of slats the determination of magnetite is therefore a matter of some importance. The difficulties in the ray of making such a determination with any accuracy are rather obvious. Iron may occur in slog as ferric oxide, magnetite, various intermediate oxides, sulphides, silicates, as free metal, and in solid solution of several of these substances. Even of only the total iron content is to be determined, accuracy can be obtained only by painstaking and time-consuming separation ions from interfering elements. The determination of ferrous, ferric, and free iron in the presence of each other is a difficult matter under the most favorable conditions, and linen present in a slag the difficulties are increased by the refractory nature of the sample, by the presence of sulphides, and by ouch elements as vanadium and molybdenum.]

Jan 1, 1931

By Paul M. Tyler

The enormous deposits of greensand in New Jersey and elsewhere in the United States, many of them close to important octant industrial centers, constitute a perpetual challenge for research chemists to convert them into a commercial asset of national importance. Following the introduction of more concentrated fertilizers, comprising synthetic mixtures of more soluble salts, the quantity of greensand used directly upon the soil has diminished, but deposits of such material still have at least potential value locally for use not only as fertilizer but also as a water softener. An annotated bibliography of the already extensive Literature on greensand, virtually complete to about the end of 1929, has been issued by the Bureau of Mines3/, and the commercial aspects as well as the technology of greensand utilization are discussed in available publications, The purpose of the present circular, therefore, is merely to provide a brief outline of certain general essential considerations for use in appraising the potential value of a greensand deposit in any given locality.

Jan 1, 1934

By Donald F. Reed

Deposits of gray hematite occur in two districts in Talladega County, Ala., the Emauhee-Tallasechatch and Weewoka, both in the; vicinity of Wintorboro, 50 miles east of Birmingham. The deposits were investigated by the Bureau of Mines in 1945 and 1944. Approximately 15,000 feet of diamond drilling was done and 6,000 linear feet of trenches excavated and sampled.

Jan 1, 1949