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By Beatrice Lukens, David Schlain, John D. Prater

"The electrolytic manganese process4/ developed by the Bureau of Mines involves the electrolysis of a solution of manganese sulfate and ammonium sulfate in a diaphragm-type cell. Metallic manganese is deposited on the cathodes, and sulfuric acid is produced at the anodes. The spent electrolyte contains, in addition to the sulfuric acid, approximately 40 percent of the manganese sulfate and most of the ammonium sulfate originally present in the feed solution. This spent solution is used to leach fresh ore that has previously been subjected to a reducing roast. The resulting leach liquor is purified and returned to the cell.Manganese of very high purity is produced by the electrolytic process. The properties of this metal are so different from those of the best grade of manganese that can be made by any other commercially feasible process that it is virtually a new material. Electrolytic manganese has been used in the preparation of new high-manganese alloys with valuable properties.3/ and further developments are to be expected. The electrolytic manganese process not only results in a product of superior qualities, but is applicable to large tonnages of domestic ores that are unsuitable for direct use in producing ferromanganese.The future industrial use of electrolytic manganese is of course, related to its cost. Decreases in the cost of production will lead to wider use of the metal; conversely, increases in the volume of production made possible by greater demand will bring further .decreases in cost."

May 1, 1946

By B. F. Naylor, C. H. Shomate, F. S. Boericke

"Ilmenite is the most important titanium-bearing constituent of titaniferous iron ores. Such ores, of which the United States has abundant reserves, are of interest because they constitute an important potential source of both iron and titanium that may be tapped in times of stress, and which eventually may be utilized in the normal course of events.As the iron and titanium constituents of titaniferous iron ores are not completely separable from each other by ore-dressing methods, any process for metal recovery will, of necessity, involve reduction of the iron in ilmenite. Consequently, knowledge of the thermodynamic properties of ilmenite should supplement information already available concerning those ores. With this in view, the Pacific Experiment Station of the Bureau of Mines undertook to evaluate thermodynamic properties; the data obtained are the subject of this report.Three types of experimental work were involved. First, low-temperature specific heats of ilmenite were measured in the temperature range 500 to 29S° K. These data serve to evaluate the entropy, a quantity necessary for a reliable evaluation and correlation of other thermodynamic properties. Second, high-temperature heat-content measurements were made in the temperature range 298° to 1,743° K. The data serve to bridge the gap between room temperature and elevated reduction-process temperatures. Finally, hydrogen-reduction equilibria were measured in the temperature range 1,220° to1,375° K. These data-give a direct measure of the free energy of reduction of ilmonite at these temperatures and, in conjunction with results of the other two types of measurements, serve to obtain the heat of formation of ilmenite, a quantity not readily determinable by direct calorimetric means.The data are correlated to form a composite, self-consistent portrayal of the thermodynamic properties of ilmenite, which may be used in evaluating the efficacy of any reducing agent of known thermodynamic properties. Selective-reduction of iron in ilmenite by hydrogen, carbon monoxide, and carbon are considered in this report."

May 1, 1946

By R. G. Knickerbocker, David Schlain, F. K. Shelton, J. H. Jacobs

"Many manganese ores contain from 0.1 to several percent cobalt. If such ores arc used for the production of ferromanganese, the cobalt is lost; on the other hand, if they are used for the production of electrolytic manganese, the cobalt can be recovered during the purification of the electrolyte.The production of cobalt in the United States is insignificant compared to the amount consumed, most of which is imported from the Belgian Congo. Cobalt-bearing manganese ores may therefore constitute an important reserve of cobalt in times of emergency. Moreover, the combined value of manganese and cobalt in some ores may be sufficient to warrant the recovery of both metals by the electrolytic manganese process, whereas the recovery of either manganese or cobalt alone might not be economically feasible.In view of the potential importance of manganese ores as a source of cobalt, a survey has boon made of the cobalt content of manganese ores. Most of the data have been obtained from analyses made in the Bureau of Mines, but valuable data have also been obtained from publications of the Geological Survey, various State publications, and other sources. Unfortunately, most published analyses of manganese ores do not include cobalt determinations; when such analyses were fairly detailed, but did not include cobalt, it was presumed that cobalt was not present in significant quantity.Information on the cobalt content of domestic manganese ores is given in table 1. Ores containing 0.1 percent or more cobalt are listed in table 2, and the districts in which such ores occur are shown in figure 1. Most of the known cobalt-bearing manganese ores occur in the southeastern part of the United States. A group of deposits in central Arizona and a few scattered deposits in other States also' contain cobalt."

Apr 1, 1946

By J. Wade Watkins, Joseph W. Horne, Arthur Matzick

"A successful procedure for the recovery of a valuable product from weathered tank-bottom settlings has been developed in the laboratories of the Bureau of lines and used in a field pilot plant. These heavy emulsion settlings, generally regarded by the industry as waste material, have usually been drained into open pits or storage ponds and eventually destroyed.Laboratory examination of the waste material shows it to consist essentially of a ""water-in-oil"" emulsion containing a considerable volume of congealed ""paraffin."" This paraffin is mainly high-melting-point wax; known in the industry as microcrystalline wax, for which there is an increasing demand.Because of the physical properties of this wax, the tank-bottom settlings are not responsive to conventional methods used for demulsifying ordinary crude-oil emulsions.The work upon which this report is based was conducted by the Bureau of Mines in cooperation with -the Kansas State. Board of Health and with special cooperative agreements-with the Cities Service Oil Co, Bartlesville, Okla., and the Bareco Oil Co,. Barnsdall, Okla. The studies were made under the general supervision of R. A. Cattell, chief engineer, Petroleum and Natural-Gas Division, Bureau of Mines, Washington; D. C., and H. C. Fowler, supervising engineer, Petroleum Experiment Station, Bureau of Mines, Bartlesville, Okla., and under the direct supervision of Ludwig Schmidt, senior petroleum engineer, Bureau of Mines, Bartlesville, Okla.Gratefully acknowledged are the assistance and cooperation given by the Cities Service Oil Co. of Oklahoma and especially by M. J. Kirwan, manager of production, and by Q. E. Beecher, general superintendent of production, Bartlesville, Okla., and to members of their staff at Oil Hill, Kans.The assistance and suggestions of V. R. Oakley, general superintendent, E. R. Wiles, director of research, L. G. Willis, field engineer in charge crude-oil supply, and Gerald DeWalt, chief chemist, and his staff of the Bareco Oil Co., Barnsdall, Okla., were of much value in the laboratory and recovery work."

Mar 1, 1946

By Kenneth L. Kreamalmyer

"The demand for open-hearth iron ore and the existence of suitable smelting facilities in the St. Louis area seemed to warrant investigation of several Missouri iron-ore deposits of the filled-sink type. Preliminary examinations were made in the autumn of 1944 by an engineer3/ of the Bureau of Nines, and in December of the same year funds were allotted for the exploration of these properties by churn drilling. Three properties, the Silver Hollow Bank and the Newbauer and Coleman properties, were drilled. Work was completed May 8, 1945.The Federal Geological Survey and the Missouri Geological Survey and Water Resources assisted in the project by determining the stratigraphy from drill cuttings and by mapping the drilled areas.The properties explored are in the hilly section of east-central Missouri and are connected by all-weather graveled roads with various shipping points of the St. Louis-San Francisco Railway system within 3 to 6 miles of each property.The Silver Hollow Bank, in sec., 8, T, 40 N., R. l W. Franklin County, Missouri, is in the Meramec State Game Reserve. The nearest town and shipping point is Sullivan, Mo„ which is 6 miles distant. The Newbauer property, in sec. 28, T. 41 N., R, 2 W., Franklin County, Missouri, is approximately 3 miles west of Stanton; The Coleman property, in sec. 14, T. 38 N., R. 3 W., Crawford. County, Missouri, is within a short hauling distance of the railway at Elayer, Mb. These are shown on figure 1.The region surrounding the explored areas contains a series of low-lying hills or ridges and narrow winding valleys drained by the Meramec River system. These hills seldom rise more than 200 feet above the valley floors, most of which are approximately 700 feet above sea level. Except for numerous small farms and a few small towns, the entire region is covered by a dense growth of timber and small brush. The St. Louis-San Francisco Railway system, U. S. Highway 66, and numerous all-weather State and county roads traverse the area."

Oct 1, 1945

By Beatrice L. Lukens, David Schlain, John D. Prater

"The electrolytic manganese process developed by the Bureau of Mines4/ and now in use in the commercial plant of the Electromanganese Corp. at Knoxville, Tenn., and in the Bureau of Mines pilot plant5/ at Boulder City, Nev., involves the electrolysis of a solution of manganese sulfate and ammonium sulfate in a diaphragm-type cell. Metallic manganese is deposited on the cathodes, and sulfuric acid is produced at the anodes.. The spent electrolyte contains, in addition to the sulfuric acid, approximately 30 percent of the manganese and most of the ammonium sulfate originally present in the feed solution. This spent solution is used to leach fresh ore that has previously been given a reducing roast. The resulting leach liquor is purified and returned to the cell.Since the presence of small amounts of certain impurities in the electrolyte may be very detrimental to the electrodeposition of manganese, the purification of feed solution is a very important step in the process. According to the purification method6/ now in use in the Bureau of Mines pilot plant at Boulder city, Nev., cobalt, nickel, iron, arsenic, lead, copper, etc., are removed by precipitation as sulfides at a pH of 6.0 to 6.5. Residual sulfides and colloidal material are removed from the resulting solution by ferric hydroxide formed by adding a small amount of iron sulfate and passing air through the solution. Feed solution purified in this way contains less than 1/2 mg.-per liter-of such impurities as arsenic, iron, cobalt, nickel, copper, etc., and is pure enough to give consistently excellent manganese deposits.Although this purification scheme has given satisfactory results at the Boulder City pilot plant knowledge of the specific effects of various impurities would be valuable. Such information would be useful in diagnosing the causes of cell room operating difficulties, and might aid in the recognition and correction of impurity difficulties arising from the use of new ores.. The purpose of this investigation was therefore, to study the effects of various concentrations of some common impurities.Since the effects of some impurities may not be apparent during short deposition periods and since harmful impurities often cause erratic results rather than consistently poor ones, it was believed that conclusions concerning the effects of impurities should be based upon the results of a fairly large number of 20- to 24-hour tests. Because of the time required for such tests, it was necessary to limit the scope of the work to a few of the more common impurities."

May 1, 1946

By M. Mahan, D. D. Blue, O. C. Garst, F. Fraas, L. Fink

"Early in World War II it became apparent that the known bauxite re- serves might not be adequate to supply the demands of the American aluminum-producing industry, as the transportation of bauxite from abroad to this country might easily be interfered with by hostile action. Consequently, the Bureau of Mines set up an intensive, well-integrated program for the production of cell-grade alumina from low-grade domestic ores. This pro-gram of investigation covered the production of alumina from clay, alumite, red mud, and other low- and marginal-grade ores. In line with the Bureau's usual policy of conservation of natural resources, it was decided that the investigation should be extended to cover the production of alumina and other valuable byproducts from aluminum dross.Statistical information showed that during the year 1943-44, an average of 2,900 tons of aluminum dross was generated monthly. This dross, after partial removal of free metal, had an average metallic aluminum content of approximately 9 percent. Some of this dross was produced by the melting of alloyed aluminum; but a large proportion 1,700 out of 2,900 tons - was generated by two producers of primary aluminum, and the dross did not contain an great proportion of alloying metals. Compared with dross from other sources, this 60 percent of the country's capacity can be assumed to have relatively uniform composition. Moreovcr, the problem of collection and distribution can be minimized because of the relatively small number of plants included in the organization of these two producers of virgin metal.Except for large pieces of metallic aluminum that easily can be mechanically separated for remelting, this dross has been discarded and scrapped. Inasmuch as chemical analyses show that the alumina content of dross is far higher-than ordinary ores - 111 percent alumina equivalent in dross compared to 57 percent alumina in bauxite - aluminum dross is a far richer source of aluminum than any known naturally occurring ores. The discard, of this waste material during the war and reconversion periods would be unsound economically. The work reported herein describes tests at the College Park Station of the Bureau of Mines on the recovery of metal, alumina, ammonia, methane, and abrasive-grade corundum from dross."

May 1, 1946

By William E. Dennis

"At the request of Philip S. Hoyt, the Eagle Mountain fluorspar deposits in section 35, block 68, Texas & Pacific Railroad Survey No. 9, were examined by an engineer3/ of the Bureau of Mines during March 1943: As a result of this examination; a preliminary program of trenching, sampling and core drilling by the Bureau of Mines was begun in. June 1943.4/ Eight deposits were explored.The Federal Geological Survey mapped the properties and furnished geologic information throughout the program, while the Texas .Bureau of Economic Geology6/ made preliminary maps that facilitated planning the exploratory work on section 35.The eight deposits explored by the Bureau of Mines are in block 68, Texas & Pacific Railroad Survey No. 9, Hudspeth County, Tex., approximately 7-1/2 miles south of. Hot Wells and 12-1/2 miles south of Allamoore, which is 10 miles west of Van Horn and 20 miles east of Gierra Blanco on U. S. Highway 80(fig. 1). A graded gravel road, built by the Public Roads Administration, leads from Hot Wells to the deposits in section 35, and there are unimproved roads, passable,by automobile, to all the other deposits.Carload shipments can be made to and from Hot Wells on the Southern Pacific Railroad, and complete railroad facilities are available at Allamoore on the Texas & Pacific Railroad.Van Horn and Sierra Blanca are the only local source of labor and. supplies. The prevailing wage for common labor is 60 cents an hour. Living accommodations are obtainable in Horn and Sierra Blanca.No electric power lines pass near the deposits. Diesel and gasoline motors are employed to furnish power for mining and milling operations.Two recently 'drilled water wells on section 35 furnish water for the mill. Other wells will be drilled if the present supply is inadequate for prolonged Peak operation.The properties lie in the foothills on the northeast side of the Eagle Mountains at 5,500 feet altitude. The Eagle Mountain Range rises sharply from a broad, flat valley known as Eagle Flat. Eagle Peak, the highest in the range, has an altitude of 7,510 feet. In the vicinity of the fluorspar deposits the topography is moderately reliefs ranging from 50 to 300 feet."

Jun 1, 1946

By Joseph B. Cummings

"Occurrences of fluorite on the Packard property were first examined by an engineer3/ of the Bureau of Mines in July 1943 as the result of receipt of an application for an access road. In August of the same year the showings were examined by a geologist4/ of the Federal Geological Survey. The property was again examined by an engineer5/ of the Bureau of Mines in March 1944. This last examination resulted in a proposal that access be gained by construction of a truck trail and that the Bureau of Mines undertake to explore the fluorite showings.The truck trail was constructed by the Public Roads Administration, which began the work on February 17, 1945, and completed it 8 days later.The Bureau of Mines exploratory program was completed on May 16, 1945. It consisted of stripping overburden, trenching, test pitting, tunneling, sampling, and topographic mapping.In addition to being described in some detail, the extent of the work as well as results are shown in accompanying tables and figures.Mrs. Rhoda A. Packard, Mrs. Nora 1. Cline, and C. B. Pettingill, all of Tonto Basin, Ariz., own the property, which comprises four contiguous, unpatented lode mining claims recorded at Globe, Ariz., as the Walnut and the Bluebird 2, 3, and 4. The claims are situated in T. 6 N., R. 11 E., Gila County. David L. Roscoe of Tombstone, Ariz., holds a lease and option to purchase.Access to the property is by Highway 88 from Globe, 34 miles to Roosevelt, thence 24 miles by a graded county road along the west side of Roosevelt Lake to Tonto Basin. Here the Greenback Ranch road, constructed by the Forest Service and maintained by the county, crosses Tonto Creek and continues easterly to the foothills. The truck trail leaves the road 8.5 miles east of Tonto Basin and runs 2.5 miles in a southerly direction to the property. (Fig. 1.)The fluorite deposits lie in and along a small canyon in a rough, rocky area at an altitude of about 3,400 feet, Vegetation is scant and of the usual desert variety. The summer climate is dry and hot and the winter climate moderate. Rainfall at the Forest Service Station in Tonto Basin was 11.4 inches from May 1944 through March 1945."

May 1, 1946

By William Seymour, L. D. Schmidt, J. W. Myers, W. T. Reid

"This investigation was conducted by the Bureau of Mines as part of a program of the Solid Fuels Administration to encourage the utilization of anthracite fines, the objective being to determine the practicability of using anthracite fines in the manufacture of packagedThe experimental loss of packaged fuel covered by this report were made at a commercial plant using the Glenn Smith process and ordinarily making packaged fuel from Pocahontas screenings. These lots included several made from straight antimacite mines and others made from various blends of anthracite fines with four different bituminous coals. In all cases an asphalt binder was used. Determinations of the physical properties and the cobustion characteristics o the various samples of packaged fuel were made by the. Bureau of Mines at the Central Experiment Station.The physical tests indicated that a packaged fuel of sufficient strength for ordinary handling can be made from straight anthracite coal or from a wide variety of blends of anthracite fixes with bitunimous coal, using asphaltic binder. However the combustion tests indicated that packaged fuel made from anthracite alone tended to crumble excessively during burning and that as much as 30 to 50 percent of a caking coal may be required In the mixture to produce a block having satisfactory combustion characteristics.The authors wish to acknowledge the. splendid cooperation of Messrs. H. W. Kelly, J. L. Mooney and C. H. Stoss of Columbus, Ohio, who were chiefly responsible for obtaining the materials and making all the arrangements necessary for the production of the packaged fuel for testing.Thanks are due to the officials of Carnegie Institute of Technology for the use of their Olsen. Testing Machine and to H. M. Cooper and W. A. Selvig of the Bureau of Mines for analyses and tests."

May 1, 1946

By W. P. Huleatt, R. B. McCulloch

"The Big Four zinc-deposit, directly above the north bank of the Green Mountain Reservoir on the Blue River, Summit County, Cole., was discovered in 1937 by the present owner, Walter McDaniel, who lives on the property. Mr. McDaniel, together with members of his family, have worked the mine on a small scale since its beginning and have shipped quantities of sorted high-grade ore to the International Smelting Co. at Tooele, Utah, and the Combined Metals Corp. at Bauer, Utah. More recently, parts of the nine have been operated by lessees.The property had been examined previously by the Federal Geological Survey, and the geological report was made available' to the Bureau of Mines.The Big Four mining claim was located in 1937 by Walter McDaniel and his wife Frances,- who had been prospecting in the vicinity since 1933. The discovery of the high-grade zinc deposit caused considerable excitement, as it had not been regarded as a mineralized area.Mining was begun in 1937 and carried on until 1944 by Mr. and Mrs. McDaniel with the help of a few hired miners. During 1944, parts of the mine were leased: to various parties Who produced small quantities of ore but did no development work.Shipments during 1941 .totaled 752 tons; during 1942, 387 tons; and during 1943, 510 tons. From the beginning of 1944 to April of that year, 98 tons wore produced and shipped to Utah,Since the lessees began operations, a grade of 30 to 35 percent zinc has been maintained by careful sorting. No production has been recorded for 1945.The Big Four mine is situated on Colorado State- Highway 9 between Dillon and Kremmling on the south face of Green Mountain overlooking the Green Mountain Reservoir, a Federal irrigation project on the Hue River, Green Mountain rises 1,600 feet above the general level of the valley to an altitude of 9,408 feet and the surrounding terrain, i s correspondingly mountainous and rugged."

Apr 1, 1946

By F. A. Rutledge

"The chromite deposits of Red Mountain, 10,miles southeast of Seldovia, Alaska, are in an intrusive of ultramafic rocks. The earliest reference to the deposits was made by U.S. Grant3/; J.B. Mertic, Jr. 4/ made a brief examination in 1917; and A.C. Gill5/ spent 7 weeks studying the ore bodies and geology of the region in 1918. The Federal Geological Survey had a field party in the region from July until September 1940 and the Red Mountain area was mapped and geological data were assembled by P.W. Guild.6/A preliminary investigation of the Kenai chromite deposits was made in July 1941 by R. S. Sanford,7/district engineer of the Bureau of Mines, accompanied by P. W. Guild, assistant geologist of the Geologi¬cal Survey. This was followed by surface sampling and core drilling, which were completed in September 1942 under the direction of John W. Cole,8 associate engineer of the Bureau of Mines. G. O. Gates, associate geologist, and A, B. Unkelsbay, junior geologist, of the Geological Survey, logged cores and interpreted geologic features revealed by Bureau of Mines drilling and trenching.9/J. C. Roehm, associate engineer of the Territorial Department of Mines; examined the Red Mountain area in august 1941.10/Additional exploration of other deposits in. the Red Mountain area was completed during the summer of 194. Work consisted of surface sampling, core drilling, and mapping. G. O. Gates, associate geologist of the Geological Survey, spent 4 days in August investigating results of the Bureau of Mines program.Throughout the exploratory work conducted by the Bureau of Mines the cooperation of Red Mountain Chromite, Inc., and especially of John Blodgett, Jr., and Collis 2, Druley, president and superintendent, respectively, was greatly appreciated. Use of their camp in the Windy River cirque and shops at Kasitsna Bay facilitated the Bureau of Mines program."

Apr 1, 1946

By R. J. O'Dea

"The United States hat large reserves of titaniferous iron ores that are a potential future source of both iron and titanium. Although it is not now economically feasible to recover iron and titanium metals from these ores, they may become important in times of stress and, in some instances, already have served as a source of pigment-quality titania.The iron- and titanium-bearing constituents of the ores considered in this report are not completely separable from each other by ore-dressing methods, and chemical (or smelting) procedures must be employed. It is im¬portant, therefore, that information be available concerting their reactivities. The most important titanium-bearing constituent is ilmenite (FeTiO3), the thermodynamic properties of which were discussed in a previous publication.3/ The results of thermodynamic studies showed that both hydrogen and carbon monoxide are relatively ineffective reducing agents for the iron in limonite. On the other hand, carbon theoretically is effective at tempera¬tures above 8510C., at which. point the combined equilibrium pressures of CO and CO2 from the reactionsFeTiO3 + C = Fe+ TiO + COand200 = C+ CO2reach 1 atmosphere.This report gives results of small-scale tests of selective reduction by carbon of the iron in titaniferous iron ores, both with and without addition of sodium carbonate. It is shown that the bulk of the iron may be reduced and separated without serious reduction or loss of titanium. Three Wyoming ores, Iron Mountain, Shanton, and Taylor, wore studied. The principal factors investigated were temperature, time, carbon:ore ratio, particle size, and sodium carbon ore ratio.Two methods of investigation were employed. In the first, intimate mixtures of ore and carbon were roasted and the reduced iron and titanium evaluated by leaching with dilute sulfuric acid and analyzing the leach solution (and, in some instances, the dried residues).Twenty grams of ore were mixed thoroughly with carbon and tamped into an alundum thimble having a loosely fitting cover. The thimble and contents were placed in a test-tube end porcelain tube and heated to the desired temperature in a Globar tube furnace. The open end of the porcelain tube was connected to a bubbler containing sulfuric acid, in a manner that permitted complete shut-off of the tube when desired. This allowed removal of the tube from the furnace at the end of the roast period without exposure of the contents to the atmosphere."

Jun 1, 1946

By S. J. Hemberger, F. W. Lee

"This project constitutes the results of a geophysical field investigation undertaken in the mining areas in the vicinity of Marion, Crittenden County, Kentucky.Results were obtained at well-known mines being worked for fluorspar. Of special interest was the determination of mineral trends at such mines, particularly in relation to the fault patterns, because of ore in them.This work also constitutes a comparison between the field information that can be obtained by purely geological means and the additional information obtained by applying geophysical surveys to the same areas.As the mineralization in this area is controlled almost surely by the faults therein, the great importance of locating faults cannot be over emphasized. Accordingly, there has been incorporated herein the analyses as well as the application of electrical resistivity methods for fault determinations.In the western part of Kentucky, particularly in that area designated as the Cave-In-Rock quadrangle by the United States Geological Survey, is located the center of the fluorspar mining district of Kentucky. From the mining as well as commercial viewpoint, this area is of considerable interest and importance. It has been described by Currier4/ as a large structural dome that collapsed, through faulting, into a mosaic composed of a main fault pattern that has a strike to the northeast in sedimentary formations. Accompanying this main fault pattern are a large number of irregular faults. This fault complex is also traversed by a dike pattern that has a regional strike for this region focusing a northwesterly direction. The faulting occurred before the dike intrusions, the latter being composed largely of peridotite rocks. According to Reed,5/ most of the metallic mineralization, composed chiefly of galena and sphalerite, occurs at or near the Intersection of the dikes with the faults, indicating a possible igneous origin of the ore deposits. Reed adds that the fluorspar generally does not follow this rule but may also be found in other portions of the faulted zone not directly related to dike intrusions. The area may be considered of equal interest in the occurrence of lead and zinc and in the occurrence of fluorspar controlled by the faults. Hatmaker and Davis6/ give detailed information concerning the form of the ore bodies and economic factors that control ore production in this area; they also suggest the application of geophysical methods in this territory. Ulrich and Smith7/ also discuss geological details in this area. This area is therefore of interest, whether examined from a large structural point of view or from a very detailed angle. The former will assist in determining the origin of the mineralization and its economic possibilities, whereas the latter will give details concerning fault locations and their geologically and geophysically controlling features. This work was undertaken as a pilot investigation relating to the study of the location of fault occurrences, in which it was attempted to determine the location of faults as well as the fault patterns in certain isolated areas. No effort was made to identify the mineralization from the gouge material in the faulted zones; this problem was left for subsequent investigations."

Jun 1, 1946

By K. L. Erickson, Gerald A. Munson

"The need for spodumene as a source of lithia for war purposes led to the exploitation of the Edison pegmatite deposit 1-1/2 miles southeast of Keystone, S. Dak. The operation was conducted during 1943 and 1944 by the Lor Mining Co., Rapid City, S. Dak. Spodumene concentrates in the ratio of 15:1 were recovered by hand picking from a sorting belt. This method was expensive and wasteful of spodumene, owing to the small size of the crystals.Data4/ obtained by the Bureau of Mines indicates that blunging with hydroflouric acid or sodium hydroxide is a prerequisite to selective flotation. Results of tests by Denver Equipment Co., Denver, Colo., indicate that economic recoveries can be obtained in an alkaline circuit after desliming.At the request of the Lor Mining Co., K. L. Erickson, metallurgical engineer, was permitted to work in the pegmatite research laboratory to verify previous investigations and to determine problems that might be involved in commercial milling. The ensuing investigation indicated that electrolytes in the mill water produced a profound inhibiting action on the flotation of Edison spodumone.An investigation of mill water from various sources showed that some waters are suitable for the process and others are not. Subsequent testing showed that all of the available waters are suitable after treatment. The flotation of the Edison spodumene in an alkaline circuit after desliming and using oleic acid as collector is efficient and economical when the water does not contain impurities.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B.Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches arc under the supervision of Dr. R. S. Dean, assistant director.As the work was of a practical nature, samples from possible mill-water sources in the southern Black Hills were obtained, and commercial softening and demineralizing methods were investigated. Data on various waters tested are given in table 1."

Jun 1, 1946

By W. A. Calhoun, M. M. Fine

"One of the most important wartime activities of the Bureau of Mines was the search for new sources of mineral necessary to the prosecution of the war. Part of that effort was in the form of metallurgical service extended to other government agencies engaged in purchasing and stock piling some of the more critical and strategic materials.Fluorite was one of the materials stock piled by the Metals Reserve Company. The fluorite was usually in the form of coarse metallurgical con¬centrate purchased in the United States and abroad. The material was stock¬piled to insure an adequate reserve of fluorite for the metallurgical industries. The domestic production of metallurgical fluorite containing a minimum effective calcium fluoride content of 55 percent,4/ however, gradually increased until production was at least equal to consumption. The stock-piled metallurgical fluorite, therefore, soon became a surplus commodity.On the other hand, the supply of acid-grade fluorite, containing a minimum of 97.5 percent calcium fluoride and n maximum of 1.5 percent silica,5/ was never entirely adequate. Increased consumption of acid-grade material in the aluminum, petroleum, and chemical industries kept that material on the critical list during the war.Under the circumstances, it was felt that a study of the possibility of producing acid-grade fluorite from the metallurgical stock piles would be of some benefit to the war effort. Consequently, samples of fluorite from several of the Metals Reserve Company stock piles were tested by the Bureau of Mines at the request of the War Production Board.Two groups of samples were submitted for testing. One consisted of metallurgical fluorite purchased from Mexico and stock-piled in the El Paso and Laredo, Texas, stock piles of the Metals Reserve Company. The second group of samples was from the stock piles at Gila, N. Mex.The sample submitted from the El Paso stock pile consisted of about 5,000 pounds of minus 4-inch material. Mineralogically, the sample consisted of fluorite contaminated by calcite, chert, quartz, and small amounts of iron and alumina. Although some of the fluorite was reasonably free from gangue at minus 1-inch, much of it remained locked in sizes as fine as 65-mesh.The Laredo sample was about 5,000 pounds of material from five different piles. The samples from each stock pile, A to E, inclusive, were analyzed separately to determine whether the grade of the material in the piles varied markedly. As there was little difference in the analyses, the samples were combined in proportion to the tonnage represented to make a composite sample for testing. The composite sample consisted of fluorite with small amounts of quartz, calcite, and barite. Most of the fluorite was the dark-colored, opaque variety. A small amount of iron-oxide staining was present, and traces of muscovite, clay, pyrite, and tourmaline were noted. The quartz was present as crystals in vugs, and as finely disseminated grains in the fluorite. The druzy quartz and the calcite were free at minus 10-mesh, but the disseminated grains, some of which were 1 to 15 microns in size, were not entirely free at minus 270-mesh. A petrographic estimate indicated that 65 percent of the silica was locked in the 150- to 200-mesh."

Jun 1, 1946

By R. H. Bedford

"The El Dorado copper mine is situated in the foothill copper-zinc belt of California, which traverses the western slope of the Sierra Nevada with unusual persistence from Butte County to Kern County, a distance of more than 300 miles. Although this area contains such important past producers as the Penn mine, Union, and others, a great part of the current production has been derived from smaller properties, which depend largely on premium metal prices for economical operation. The El Dorado mine is in the latter group, which constitutes an important source of metal in a national emergency.Exploration by the Bureau of Mines by means of eight diamond-drill holes Indicated narrow, intermittent lenses of copper ore along structures boo feet in length. The copper occurs in massive sulfides composed of chalcopyrite, pyrite, pyrrhotite, and minor quantities of bernite. The sulfides have evidently replaced tuffs, which are interbedded with the Mariposa slates and shales.H. A. Weiler and Hal T. Hall, owners of the El Dorado copper property, requested an examination by the Bureau during the latter part of 1914. In December of that year an engineer of the Bureau of Mines visited the mine and recommended the project work undertaken. The purpose was to aid the owners in bringing the property into production of copper and zinc, which at that time was critically essential to the war industries.Complete factual data obtained by the exploration are embodied in this report.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G, Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.Acknowledgment is made to A. O. Johnson, chief, Reno Division, Mining Branch, and Lowell B. Moon, chief, Mining Branch, for their aid and direction."

Jun 1, 1946

By E. M. Frost

"Helium has great value to the oil and as industry as a tracer gas, according to tests just completed in the Elk Hills Field, Naval Petroleum Reserve No. 1, Kearn County, California. When used as .a tracer gas, small percentages of helium are mixed with natural gas pumped into a reservoir for conservation, repressuring, or cycling purposes. Because minute quantities of helium added to natural gases can be detected by analytical methods and accurately determined, the variations of the helium content of gas withdrawn from various parts of a field when helium has been added to the injected gas give interesting and long-sought data on the movement of injected gas through reservoirs.The Bureau of Mines engineers began their studies of the use of helium as a tracer material in gas-injection operations in the Elk Hills, California, oil field, Naval Petroleum Reserve No. 1, in response to a request by the Navy Department for assistance in connection with an expanded oil-production program instituted in that field. This report discusses the Bureau's work on the problem of determining the direction and extent of migration of injected gas in the Elk Hills reservoir by the use of helium as a tracer gas,The Bureau appreciates the cooperation and assistance of Commodore W. G. Greenman, U.S.N., director, and Commander R. Walling, U.S.N.R., Assistant director, Naval Petroleum .and Oil Shale Reserves, Washington, D. C., Captain H. P. Stolz, U.S.N.R., commanding officer, and Commander F. G. Taves, U.S.N.R.., of the Navy's Elk Hills staff. The Bureau also appreciates the cooperation and assistance given by V. O. Wankowski, F. C. Tratt, Marray Putnam, Dana Champion, and other personnel of the Standard Oil Co., of California, operators of the Elk Hills field.R. A, Cattell, chief, and C. C. Anderson, assistant chief, Petroleum and Natural Gas Division; C. W. Seibel, supervising engineer, Bureau of Mines Helium Plants; and H. H. Hinson, petroleum engineer - all of the Bureau's staff - furnished valuable advice and assistance during the course of the work. H. C. Miller and G. B. Shea of the Bureau's San Francisco Office contributed valuable liaison work. The writer wishes to express appreciation to all these people for their cooperation and assistance."

Jun 1, 1946

By Glen C. Reed

"The Avon mica district of Latah County, Idaho, is situated on a heavily forested spur of the Thatuna Range at an average altitude of 4,000 feet. The nearest rail connection is at Avon, a small farming settlement 7 miles to the south. The main supply point is Moscow, Idaho, which is 35 miles by graveled and graded county roads from Avon.Discovery of mica-bearing pegmatites in 1885 was followed in 1888 by exploitation of several outcrop deposits. Although factual data are unavailable, past production appears to have been well in excess of $100,000. Recent production (September 191 to April 1945) amounted to 65,824.78 pounds of trimmed sheet mica and 33,294.17 pounds of punch mica having a total gross value of $434,298.The several properties of the district are variously owned by estates, individuals, and the State. When active, all wore under lease or sublease to individual operators.The deposits are in an area of pre-Cambrian schists adjacent to a small granitic outlier of the Idaho batholith. The pegmatites are nearly concordant in dip and strike to the foliation of the enclosing schists. The more persistent bodies are usually tabular, lenticular, or pegmatite. Individual dikes range in length from 10 feet or less to 300 feet.The recoverable crude mica content of the pegmatites ranges downward from a maximum of 115 pounds per ton of pegmatite mined. Material discarded in rifting and trimming operations further reduces recovery to a maximum of 5 pounds per ton -of pegmatite mined. The average recoverable sheet content of the 'recently operated .deposit is estimated at 2 pounds per ton of pegmatite -mined. Available data indicate that about 21 percent of the district's recent production of trimmed sheet mica has been ""Group A"" material suitable for exacting condenser requirements. A few of the dikes contain local concentrations of beryl.Reserves of the three known major deposits of the district are estimated at about 600 to 1,000 tons of combined ""indicated"" and ""inferred"" crude block mica. One of these deposits is inferred to contain between 150 and 450 tons of beryl.It is believed that those mica reserves are minable only under a cost-market price ratio similar to that established during 1943 and 1944. A small part of the reserves can be ""high-graded"" under the present price structure. Profitable recovery of the beryl would require a market price four to five times that paid in 1944.Preliminary examination of the Avon mica district was made by the Bureau of Mines in the summer and fall of 1942. A study of the Muscovite mine and a brief reconnaissance of the surrounding district led the Bureau to recommend that the district be explored by angle-dozer trenching."

Jul 1, 1946

By E. M. Frost

"A new apparatus has been devised for quickly and precisely analyzing natural gas for its helium content. The following outstanding advantages make it far superior to any equipment now available for the purpose.3/4/5/6/1. It enables more rapid determinations to be made.2. It has far greater sensitivity than previous apparatus. 3. It is portable.Fifty or more samples may be analyzed in an 8-hour day with the new apparatus and procedure. A maximum of about 10 samples per day could be analyzed with previous apparatus. In the apparatus described, the volume of pure helium obtained from a sample is determined by measuring the pressures created by that pure helium when it is expanded into a constant calibrated volume. In older methods the pure helium separated from a sample is pumped into a burette and measured at atmospheric pressure. The new apparatus and Procedure used with it reduce the average time for an analysis from about 40 minutes to less than 10 minutes,Samples containing a few thousandths of a percent helium may be analyzed as readily as samples containing 1 percent or more, This was not possible with former apparatus. Duplicate samples containing a few thousandths of a percent helium have been analyzed, results checking to one ten-thousandth of a percent. Attempts to measure a corresponding volume of helium in a burette at atmospheric pressure become futile. The ability to determine very small quantities of helium has become of great importance recently in gas- and oil-field engineering studies such Os the utilization of helium as a tracer gas in following the movement of gases through underground structures.A complete apparatus was recently carried more than a thousand miles in a passenger automobile. It arrived without breakage, was .set up and ready to make an analysis in a few hours. .Former apparatus was not portable. The portability of the present apparatus permits taking the apparatus to the field for more efficient prosecution of field engineering problems. The only services required in the field are electricity, tap water, and a source of liquid air or liquid nitrogen.The principle involved is based upon the fact that large volumes of all the constituents usually found in natural gas, except helium, are adsorbed quantitatively on cocoanut charcoal that has been cooled to the temperatures of liquid air. A volume of sample is measured and transferred to a tube of cocoanut charcoal maintained at the temperature of liquid air. After adsorption of all the constituents other than helium, the charcoal tube is connected to a sensitive pressure-measuring device, and the Percentage helium originally in the sample is calculated from two pressure readings and the volume of the original sample."

Jun 1, 1946