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By Constantine C. Popoff

During 1946 several limestone deposits near Fortson, Snohomish County, Wash., were examined by the Bureau of Mines. These examinations were part of a long-range investigative program of regional mineral supplies required by the anticipated industrial development of the Pacific Northwest. The .study outlined in the following paper was specifically undertaken to disclose new sources of high-purity limestone and to appraise, their economic aspects. The deposits examined -namely the Galbraith, Climax, and Hi, Hi -are somewhat similar in physical features and geologic environment. They are lenticular and belong to the same formation of metamorphosed sediments that underlies the prominent Whitehorse Ridge.

Jan 1, 1949

By Paul S. Schopf

The results of an experimental investigation into the possible use of medium energy acoustic fields (130 to 140 dB) to precipitate 1 to 10 micron particles is presented. The aerosol was produced with a LeMer generator using oleic acid and nitrogen. The sound field was a sinusoidal standing wave field in an acrylic tube, with light transmission data used for concentration determination. The results showed collection efficiencies of up to 80% on 2 micron particles with a residence time of 11.8 seconds at a sound pressure level of 139 dB re 2x10-5 N/m2. A discussion of the possible turbulent mechanism is made, as well as review and comparison with others? work.

Jan 1, 1972

By Welby G. Courtney

The Bureau of Mines conducted an exploratory field survey to determine the amount of airborne coal dust, the size distribution of the dust, and the rate of dust deposition in coal mine airways. The survey was taken at eight underground locations in operating coal mines. The rate of dust deposition in the airways depended upon the concentration of air-borne dust and decreased exponentially with distance from the dust source. The rate was seemingly independent of the size of the airborne dust particles. The rate of deposition, along a return, for the coal dust from a fade being mined with a continuous mining machine closely matched the rate for the rock dust from a trickle duster. A sample rock-dusting schedule for that return is presented; that is, the trickle duster should be operated for 3-112 hours after every five shifts to protect the average deposit of new float coal dust in the return, but operation after every three shifts is preferred, to protect an occasional heavier deposit.

Jan 1, 1982

By R. V. Holmes

The properties of the Colorado Copper Co. in Sinbad Valley, Mesa and Montrose Counties, Colo., were rehabilitated and sampled by the Bureau of Mines in October, November, and December 1942. The several deposits were reexamined in March and April 1945 to obtain information disclosed by company work after December 1942. The development program included surface trenching, rehabilitation of several edits, and channel sampling of the exposures. Assay determinations wore made on 204 samples from the surface and underground workings. The results are given in the appendix. Several copper deposits in the Sinbad Valley area are similar in origin. The host rocks are sedimentary and mice in age from Pennsylvanian to Cretaceous. The Colorado No. 3 deposit occurs in the Cutler formation, which consists of many small lenses of conglomerate, sandstone, and shale. Mineralization is closely associated with faulting. On the Pyramid group the enrichment occurs in a zone of fracturing and jointing end also spreads into the adjoining sandstone. The ore deposition on the Copper Rivet claim is associated with a fault zone and is confined to en area above the contact of the Dolores-Wingate formations. Mineral deposits on the Sinbad claims occur at intersections of faults with blue-gray Pennsylvania limestone. Copper enrichment occurs along faults and as replacement of the surrounding limestone. Metallurgical tests indicate that ores from the Colorado No. 3 and Pyramid claims can be treated successfully by leaching with sulfuric acid. This method cannot be applied to ores from the Copper Rivet or Sinbad deposits because of high calcite content. Flotation tests at Boulder City, Nev., showed a recovery of less than 60 percent with a 14.24 percent copper concentrate.

Jan 1, 1952

By K. C. Dean

Horizontal and vertical air classification systems were tested individually and in simulated tandem use for the recovery of ferrous and nonferrous metals and of other noncombustible and combustible products from shredded urban refuse. The horizontal air system with a larger tonnage throughput was used to obtain preliminary separations, and a smaller capacity vertical system was used as a cleaning device. Air elutriation, magnetic separation, and screening of shredded minus 6-inch municipal refuse recovered 92 percent of the metal in a relatively clean iron product contaminated only by adhering coatings or entrapped materials, recovered 97 percent of the combustibles in a 97-percent combustible product, and rejected 88 percent of the nonmetal noncombustibles. Cleaning of the preliminary combustible fraction produced a 98-percent paper product while rejecting other combustibles (plastics, rubber, textiles, etc.) into a 94-percent combustible product. Retreatment of the preliminary noncombustible fraction produced a relatively clean glass product.

Jan 1, 1971

By M. H. Stanczyk

The Bureau of Mines made bench-scale laboratory tests on a sample of typical Florida phosphate slime to determine alumina and phosphate extractions obtainable by agitation leaching, by baking and curing, and by a leach-electrolysis scheme. Recovery of mineral values from leached slime pulps by resin-in-pulp ion exchange contact and the reaction of the leached pulps to filtration, flocculation, and settling were also investigated. The best extractions of alumina and phosphate were obtained by (l) agitation leaching with sulfuric, hydrochloric, or nitric acid at an elevated temperature or (2) curing or baking the slime with sulfuric acid. Alumina extractions ranged from 80.8 to 90.0 percent and phosphate extractions ranged from 93.3 to 98.4 percent when the slime was leached at 90° C with sulfuric, hydrochloric, or nitric acids. Baking the slime with sulfuric acid at 200° C for 4 hours yielded an alumina extraction of 92.3 percent and a phosphate extraction of 97.0 percent, whereas curing with sulfuric acid at 100° C for 24 hours gave slightly higher alumina and phosphate extractions. Flocculation and settling properties of the slime were virtually unaffected in all cases. Filter area requirements, although somewhat improved as compared to untreated slime, remained relatively high. The lowest filter area requirement obtained was 44 square feet per ton of dry solids treated per day. Contacting leached slime pulps with ion exchange resins depleted the leach pulps of solubilized values; however, the filtration and settling properties of the barren pulps were unaffected. A leach-electrolysis scheme resulted in some concentration of solubilized phosphorus, but the method showed little promise of being commercially feasible.

Jan 1, 1966

By Leon W. Dupuy

Marquette's first reported the existence of iron In Missouri in 1673. Recorded production wan begun in 1815, increasing in size and importance until 1888, when the low price of iron resulting from Minnesota's production of high-grade ore caused most of the operators to close down. Missouri's iron production came from three types of ore: (l) Brown ores, including the deposits of primary and secondary limonites in southeast and southwest Missouri, (2) hematites of the filled sinks, including the ores of Central Ozark district, and (3) specular ores in porphyry, including the deposits of the St. Francois Mountains.

Jan 1, 1949

By M. W. Pullen

It is recognized that the determination of electrical resistivity of the earth within a given area may furnish information concerning the location of certain mineralized strata of economic importance. Present knowledge of the electrical resistivity of the various rock formations is almost nil, and the geophysicist who is detailed to make a survey of an area without any data as to the relative resistivity of the underlying rocks is greatly handicapped. Such surveys are usually made within areas known to contain mineral deposits to aid in locating desirable points for drilling. Usually these areas have been prospected by diamond drilling, and drill cores of the various rocks and ores are usually obtainable. Were it possible to make resistivity tests in a laboratory of the drill cores or from pieces of the rocks and ore within an area before attempting a field survey, this would indicate not only the advisability for such a survey but would aid considerably in the interpretation of the results of such a survey. To be of most value a definite method should be used for all such tests, and as yet such a method has not been established.

Jan 1, 1929

Develop geophysical techniques suitable for enhancing miner safety. Specifically, to use geophysical methods to detect hazardous conditions in a rock mass in deep underground mines as well as to assess the mechanical integrity and monitor changes of the rock.

Jan 1, 1997

By R. E. Heithecker, Van A. Mills

"Crude oils are capable of dissolving quantities of gas under pressure. This fact has been known for some time, but questions have arisen as to the effects of gas in solution upon the characteristics of the oil. Previous investigations4 show that gas in solution in an oil affects the viscosity and surface tension of the oil, but the effects on the volume and A. P. I. gravity of the oil have not been known. The results given in this report show that there is a decided change both in volume and in the A. P. I. gravity of the oil due to the solution of the gas in the oil under pressure. As gas is dissolved, the volume of the oil and the A. P. I. gravity increase. The converse of this phenomenon is also true: if the gas is released from a saturated oil, there is a shrinkage in volume and a decrease in A.P.I. gravity due to the release of gas from solution. However, various oils show marked tendencies to retain a portion of the dissolved gas upon releasing the pressure to that of the atmosphere. This retained gas has an appreciable effect on the volume and A. P. I. gravity of the oil because the oil does not resume its initial volume or gravity while it retains dissolved gas. In a sense the oil has been ""freshened"" and will not return to its original or weathered volume until it loses some of the lighter fractions. Wiggins5 has shown that a fresh oil decreases both in volume and in gravity because of the weathering of the lighter fractions while the oil is standing in storage tanks.This paper includes data attained during the determination of volume and gravity correction factors to be applied in the oil recovery investigations of the Bureau of Mines. Three oils having a wide range in gravity were used in determining the correction factors. These oils were from the Bartlesville-Dewey field, Oklahoma, the Seminole field, Oklahoma, and the Inglewood field, California. The same gas that was used in the oil recovery experiments was used throughout this investigation. Determinations were made of the volume and A.P.I. gravity increases resulting from the gas going into solution at 200, 400, 600, 800, and 1,000 pounds pressure; also the increases in the volume and gravity of the oil due to retained gas were determined after the dissolved gas was liberated from solution by releasing the pressure to that of the atmosphere.Samples of residual and liberated gas were taken throughout the investigation in order to study the selective absorption and selective retention by the oil of the various constituents of the gas. The analyses of these gas samples showed that there was selective absorption and selective retention of the constituents of the gas. The tests on Inglewood crude gave the most pronounced example of selective absorption and selective retention of the gas.All of the tests were conducted at a constant temperature of 709F."

Oct 1, 1928

By Floyd D. Everett

The Cougar Spar property is in southwestern Beaver County, Utah, approximately 35 miles by road northwest of Lund, a station on the mainline of the Union Pacific Railroad (fig. 1). Original fluorspar discoveries on the property were made a. short time before 1941. During 1941 lessees produced approximately 600 tons of ores averaging 40 percent CaF2. Bureau of Mines engineers examined the property in 1942 and recommended development. Work was begun in December 1942 and completed in October 1943. The area was mapped by members of the Federal Geological Survey during the project period. Development included surface trenching; drifting, and crosscutting, a short distance below the outcrop. The surface work comprised a total of 440 linear feet of bulldozer and hand trenches. A total of 550 feet of workings was driven on the 100-foot level. Samples were taken for assay from the trench exposures and from the underground workings as work progressed. Pocks in the area of the Cougar Spar property are igneous and consist mainly of fine-grained tuff and quartz monzonite porphyry. The fluorspar mineralization occurs in a northwest fault zone.

Jan 1, 1951

By M. M. Barr

Rapid expansion of the titanium-metal industry focused attention upon ilmenite as a possible substitute for the more expensive and less abundant rutile in producing titanium tetrachloride. Most of the rutile available for this use is imported. Preliminary studies were undertaken to determine the chlorination characteristics of high-titanium slags produced by electric-arc furnace smelting of alluvial Idaho ilmenite at the Federal Bureau of Mines Northwest Electrodevelopment Experiment Station, Albany, Oreg. Low silicon, calcium, and aluminum contents of the slags enhanced their potential value for chlorination.

Jan 1, 1958

By E. C. Tarpley

The Federal Bureau of Mines has studied solvent extraction as a means of concentrating the mineral components in coal. Solubilities of a number of American coals were determined using abietic acid as a solvent. The effect of rank on solubility was investigated, and maximum solubility was found with coals of intermediate rank. Vitrinite is the most soluble petrographic component; fusinite, micrinitc, and exinite are nearly insoluble. Spore exines also have a low solubility. Abietic acid is a hydrogen donor and reduces pyrite to ferrous sulfide. Mild hydrogenation of high-molecular-weight fragments of the coal structure to those of lower molecular-weight probably contributes to the solvent action. Even where solubility of the coal substance exceeds 90 percent, contamination of the mineral matter with coal makes identification of the mineral components difficult. Further separation might be possible by the application of float and sink techniques to the residue. INTRODUCTION Work n the solvent extraction of coal is conducted to recover commercially useful products and to characterize coal;. and obtain information on their structure. Some coals, particularly those of low rank, contain waxes, resins, and humic acids which can be removed by solvent extraction and find varied industrial uses. In World War II, solvent extraction of coal was conducted on a commercial scale in Germany to obtain a low-ash feed material for hydrogenation and to produce electrodes carbon for the aluminum industry.4 5/

Jan 1, 1960

By Robert F. Droullard

The Bureau of Mines has investigated techniques of using gross alpha or beta detectors to continuously measure working levels. Both methods measure radioactive particulates collected on a filter paper using a constant airflow. Inherent-error studies indicate a value of about ±3 percent for the gross alpha method and about ±8 percent for the beta method in typical mine atmospheres. However, the beta method avoids problems associated with alpha detectors and is therefore more useful. Applications of these continuous working-level detectors include work area monitoring of exposure levels in underground openings, such as mines and caves, and calibrating personal dosimeters exposed over extended time intervals.

Jan 1, 1977

By Michael Hamilton

Mineral resources have been identified at two properties in the Ten takes RARE II area (table 1). Commodities consist of copper and silver. The deposits, in the northwest part of the study area, are hydrothermal and associated with fissure veins that developed along northwest-striking faults within the Precambrian Purcell Lava. In addition to the identified resources, there is high potential for additional copper-silver resources at these properties and moderate potential for copper-silver-lead-zinc-bariun resources at five others (table 2) in the portion of the study area that is underlain by the Purcell. There is no evidence that significant mineralization occurred in strata above or below the Purcell.

Jan 1, 1983

By H. J. Lechtenberg

This Bureau of Mines report investigates solvent injection as a means of increasing oil production from low-gravity oilfields; thus, wells in two California oilfields that produce from reservoirs having low-gravity oil were injected with highly aromatic solvents to increase their oil recovery. The wells were either allowed to soak or the solvent was circulated for a period of time. In some of the wells, the solvent was followed by a slug of water. The post-stimulation production rate was considerably higher than the prestimulation rate of the wells. Wells in which the solvent was not followed by water showed an immediate increase in oil production, and essentially all of the solvent was recovered. The wells in which solvent was followed by water essentially showed a delay in the increase in oil production, thus indicating a temporary water block. The results show that the production rate is usually increased by the injection of solvent, and the method may prevent early abandonment of marginal producers. Cumulative post-stimulation oil production indicates that cyclic solvent injection treatment can be an economic success.

Jan 1, 1974

By J. J. Forbes

The investigation of major and minor coal-mine disasters has been a routine function of the Bureau of Mines since its inception in 1910, and the facts obtained during such investigations have been used as a basis for determining the precautions that the managements and employees of many mines are observing to forestall similar occurrences. The Bureau has conducted research on roof-control and other mine problems, but a comprehensive study of other fatal accidents was not attempted until February 10, 1950, when the policy of investigating all coal-mine fatalities in the United States was approved by Bureau of Mines Director James Boyd. The investigations are being conducted by Federal coal mine inspectors functioning under the provisions of the Coal Mine Inspection and Investigation Act of May, 1941, Public Law 49; and reports covering the investigations are distributed to management, the State mine-inspection agency, and representatives of the mine workers' organization have jurisdiction at the mine.

Jan 1, 1951

By R. G. Knickerbocker

[The Electromet l'.ur.::ic'l.l LC:tt:n~ to:!'"' of' the BUl~6au 0: M_nes, Boulder City, ..rev. I invest~.f-'8tes th~ r.: nc= I (l.op itr. in tr.e redon around Boulder Dam, and thi" p2pe:.. ., 'est.3nttl t rt") d.c-velo !l'\CtltR of n seriAl of studies on "Joron uineral~ mario n.~ t~l"'t f1tn.: ... o]

Jan 1, 1940

By D. E. Fogelson

In a factorial experiment, blasting caps were detonated in three sizes of shotholes in mortar with three types of stemming--dry sand, wet sand, and hydrostone. Free-surface displacement pulses were recorded with a capacitive-displacement gage at a distance of 15 inches. The effects of decoupling and the type of stemming on the amplitude and the duration of the displacement pulse were determined. Both the amplitude and the duration of the displacement pulse were significantly decreased by increasing the decoupling, but they were little affected by the type of stemming.

Jan 1, 1965

By R. C. Hickman

"INTRODUCTION .As part of its spot drilling program, the Bureau of Mines core-drilled seven holes on the Alexander and Barber properties in Spartanburg County, S. C.Extensive surface float and outcrops of sillimanite schist on these properties appeared to justify drilling, which did not prove satisfactory, however, owing to the spotty occurrence of the schist bodies and the poor core recovery in the decomposed schist.ACKNOWLEDGMENTSIn 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, Oliver C. Ralston, chief, analyzes samples and performs beneficiation tests.This project was under the immediate supervision of Mitchell H. Kline, chief, Raleigh Division, Mining Branch, Bureau of Mines.LOCATIONThe Alexander and. Barber properties are in the southern part of Spartanburg County, S. C. The Alexander property is about 5 miles cast of Woodruff. It is reached from Woodruff by driving east 5 miles on a macadam road to the intersection with an unsurfaced road near Unity Church. The farm house on the property is 0.4 mile north on this road. The sillimanite outcrop is in a field approximately 1,200 feet east of the farm house. The Barber property is about 2 miles north along the unsurfaced road that passes the Alexander property."

Sep 1, 1947