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By Van E. Shaw, D. J. Bauer

Conversion of euxenite concentrate to sulfates with sulfuric acid and solvent extraction of the yttrium- rare - earth mixture with EHPA were studied to determine extraction and separation characteristics . Digestion with 3.5 pounds of 96 percent sulfuric acid per pound of concentrate at 336 ° C for 4 hours resulted in an easily handled product with a yield in excess of 98 per- A thorium- free product was obtained by calcining the sulfated material for 3.5 hours at 650 ° C prior to leaching with water . Di ( 2 - ethylhexyl ) phosphoric acid solvent is an effective extractant with preference for cerium ( IV ) and heavy - group rare - earth elements including yttrium . Separation of complex rare - earth mixtures into light- and heavy - group fractions is feasible , and these fractions can be further processed to isolate ytterbium , neodymium , and dysprosium by changing processing conditions to obtain separation factors greater than two between these and adjacent elements .

Jan 1, 1965

By E. A. Rowe, G. H. Keith, B. D. Jones

An evaluation of electrowon tungsten powder was made by comparing its characteristics with conventional hydrogen - reduced tungsten powder . Electrowon tungsten powder was investigated with respect to particle size and shape , apparent density , flow rate , compressibility , green strength , and sintering characteristics . In addition , its chemical purity , absolute density , and purification by melting were determined . Significant findings were higher flow rates and better compressibility than hydrogen - reduced tungsten powder . However , the large particle size peculiar to the electrowinning process effectively prevented conventional sintering to a high- density material . The possibility of producing high - density material , using a new technique of hot swaging sheathed sintered - tungsten compacts , was demonstrated by the achievement of densities of 92 percent of theoretical .

Jan 1, 1965

By W. H. Frederic, F. H. Gibson, R. F. Abernethy

This publication contains the quantitative values for phosphorus , chlorine , sodium , and potassium in United States coals . The samples tested were taken from commercial shipments and have been selected to represent the principal coal producing areas of the country . Due to combining the analytical results from two separate surveys , values for the four elements are not available for all samples .

Jan 1, 1965

By J. R. Ross

Techniques for recovering scandium from uranium plant iron sludges and from wolframite concentrates are described. The best procedure found comprised (1) dissolution with sulfuric acid, (2) preliminary concentration by solvent extraction with a primary alkyl amine, (3) further enrichment and purification by a combination of ion exchange, solvent extraction, chemical precipitation, and calcination. Recovery of scandium from these raw materials, which contained 0.058 and 0.14 percent scandium, ranged from 83 to 90 percent in products analyzing 99.6 to 99.9 percent scandium oxide.

Jan 1, 1965

By John Nagy

Results of initial research by the Bureau of Mines are given on the dust explosion hazard of float coal and on the related factors of occurrence, rate of production, sampling techniques, transport, and deposition of float coal. Tentatively, it is suggested that where float coal deposits prevail, a mini-mum of 80 percent incombustible be maintained in the top 1/8-inch layer to neutralize the explosion hazard of the surficial coal deposit.

Jan 1, 1965

By R. V. Lundquist

The specific conductance of solutions of sodium hydroxide and of sodium aluminate was directly proportional to the temperature. The specific conductance of sodium aluminate solutions with identical sodium ion concentration and at constant temperature decreased with increase in aluminum concentration. The aluminate ion population in solution was shown to consist of a mixture of monovalent and polyvalent ions. Aluminate ions did not influence the temperature dependence of pH in caustic solutions containing sodium aluminate. The density and viscosity of a solution was inversely proportional to the temperature and directly proportional to the concentrations of sodium and aluminate ions.

Jan 1, 1965

By B. B. Letson

The heats of formation of lithium chloride and lithium oxalate were determined with the aid of a Bureau-developed, glass Dewar-type solution calorimeter which uses thermistors as its temperature sensing element. Values obtained at 298.15° K were -98.38 ± 0.54 kcal/mole for lithium chloride and -329.02 ± 0.79 kcal/mole for lithium oxalate, using graphite as the standard state for carbon.

Jan 1, 1965

By W. W. Agey

An inexpensive technique that laboratory studies indicated would significantly reduce seepage in irrigation canals was devised and tested through research sponsored by the Bureau of Reclamation and the Missouri River Basin Field Committee. Laboratory tests simulating optimum field conditions determined that easily applied sodium carbonate solutions made test beds of canal lining materials virtually impermeable for long periods. The study comprised alternative laboratory treatments of 3-inch-deep test beds of canal earths with 74 water-soluble chemicals in search of one 01' more that would effectively improve the water barrier characteristics of the component clays. Sodium carbonate, one of the least expensive, was among the most effective. The addition of 0,4 lb of reagent per sq yd greatly reduced the seepage from typical, highly permeable test beds. The reagent penetrated and sealed surface for about a 1.5-inch depth.

Jan 1, 1965

By John S. Berber

Tar produced as a byproduct from low-temperature carbonization of coal contains only small amounts of valuable lower boiling tar acids but relatively high percentages of high-boiling tar acids. These high-boiling tar acids are characterized by a high degree of alkylation and can be converted into the lower boiling homologs by catalytic treatment to remove the alkyl groups or decrease their chain lengths.

Jan 1, 1965

By Manuel Gomez

Carbon number distributions were obtained for tar acid fractions from five low-temperature tars by low-ionizing voltage mass spectrometry. Quantitative data for phenols representing seven structural compound types were examined by statistical analysis. It was shown that for the phenols discussed, the data could be represented by regression equations expressing phenolic concentration as a function of the reciprocal of the carbon number and the carbon-to-hydrogen ratio of the parent coal. The total concentration of each structural type present was found to depend on the molecular weight and boiling point of the initial member of the group. Carbon distribution data for the tar acid fractions studied support the view that low-temperature tars contain the same chemical compounds but in different proportions.

Jan 1, 1965

By Mulligan John J.

The Bureau of Mines investigated lode tin deposits on Potato Mountain, Seward Peninsula, Alaska. Tin was found to occur as cassiterite associated with quartz, tourmaline, pyrite, arsenopyrite, and earthy clays, but the deposits lack the varied accessory minerals commonly found in tin districts. The tin-bearing deposits are in metasediments along minor breaks and bedding planes but not in the crushed earthy filling of major faults. Cassiterite and sulfides occur with quartz in veins, both with and without earthy clays, and disseminated through tourmalinized wall rocks. The deposits are characterized by irregular segregations containing 1 to 10 percent tin within zones averaging not over 0.25 percent tin. The largest segregation exposed is on the summit of a low hill on the east-central slopes of Little Potato Mountain; most of the outcroppings are in an area trending east to west, roughly 10 to 30 feet wide and 300 feet long. Sample values ranged as high as 12 percent tin, but the average grade may be about 1 percent tin. The extreme irregularity of both grade and composition precludes a more exact determination. Similar concentrations are scattered for over 1,000 feet to the west and north, but these are smaller and lower in grade. Elsewhere on Potato Mountain, generally similar deposits occur as clusters of veinlets at widely separated points in the metasedimentary walls of major faults.

Jan 1, 1965

By Oliver Q. Leone

The effect of oxygen content in the anode metal on titanium electrorefining characteristics was studied. Increasing quantities of oxygen in the anode resulted in increased anode scale formation, decreased anode and cathode current efficiencies, lower titanium recovery efficiencies, and higher oxygen content of the cathode products. The titanium electrorefining process performed best when the anodes did not contain more than 0.5 percent oxygen, although anode dissolution was recorded for alloys containing up to 25 percent oxygen. Back emf affords a useful index of an alloy to electrorefining.

Jan 1, 1965

By James S. Browning

The Bureau of Mines conducted laboratory batch and small-scale continuous flotation tests of weathered mica pegmatite ores from Alabama and North Carolina to determine the technical feasibility of recovering commercial-grade mica concentrates. A new anionic-catonic method was developed for recovering mica in the presence of clay slimes. In continuous tests, concentrates containing 98.1 percent mica were obtained from the Alabama pegmatite ore; the North Carolina pegmatite ore concentrates contained 97.2 percent mica. The recoveries were 83.8 and 81.6 percent, respectively.

Jan 1, 1965

By H. J. Heinen

A technique offering promise as a metallurgical processing sequence the recovery of molybdenum (Mo) from the sulfide mineral--molybdenite?was investigated. The method consists of two steps: (1) electrosynthesis of pure dimolybdenum carbide (Mo2C) from molybdenite (MoS2) and (2) interaction of Mo2C and molybdic oxide (MoO3) to produce pure molybdenum metal. Two molten salt systems were satisfactory for electrosynthesizing Mo2C. The first was a mixture of potassium chloride (KCl), potassium fluoride (KY), and sodium metasilicate (Na2SiO3), and the second consisted of sodium fluoride (NaF), KF, sodium tetraborate (Na2B4O7), and sodium carbonate (Na2CO3). Yields up to 0.42 gram of Mo2C per ampere-hour were obtained. The carbide, mixed with monitored amounts of MoO3, was converted to molybdenum metal of 99.9 percent purity by sintering at 1,500° C.

Jan 1, 1965

By Tilman M. M.

The effects of substituting cobalt for nickel on the acid corrosion resistance of two types of austenitic stainless steel were determined. Cobalt substitutions to a maximum 2.2 weight-percent were made in types 302 and 309 stainless steels. Total immersion corrosion tests were made in 10 volume-percent hydrochloric acid, and boiling-acid tests were conducted in 65 weight-percent nitric acid and in undiluted glacial acetic acid. For modified type 309 in acetic acid, corrosion rates decreased for additions greater than 0.57 weight-percent cobalt. Corrosion rates increased as cobalt was increased up to about 1 weight percent for modified type 302 in nitric and hydrochloric acids and for modified type 309 in nitric acid, but these rates decreased with a further increase in cobalt content. A gradual increase in corrosion rates with increasing cobalt content was shown for type 302 in acetic acid and for type 309 in hydrochloric acid. Cobalt substitutions in larger amounts (above a ratio of 8 Ni to 1 Co) may increase the corrosion resistance of the austenitic stainless steels.

Jan 1, 1965

By L. B. Pankratz

Heat content measurements were conducted for GaPo.996 and InPo.986 over the temperature range from 298° to 1,100° K, and for In2S2.897 over the range from 298° to 1,200° K. Both the actual experimental data and values adjusted to conform with the stoichiometric compositions (GaP, InP, and In2S3) were reported. Entropy increments above 298.15° K were calculated for the stoichiometric compounds, and heat content and heat capacity equations were derived.

Jan 1, 1965

By R. V. Lundquist

The compound 2Na2O?3CaO?5Al2O3 occurs as a minor phase in lime-soda sinters prepared for extracting aluminum from siliceous aluminum-bearing materials. About 99 percent extraction of sodium and aluminum from synthesized 2Na2O.3CaO.5Al2O3 was obtained in solutions of NaOH-Na2CO3 at leaching temperatures of 50° C and above. Extractions in water were low because insufficient NaOH was generated by hydrolysis. Extractions in NaOH solutions were limited to about 80 percent owing to the precipitation of hydrated calcium aluminates. Rapid extractions of 100 percent were obtainable in NaaC03 solutions, but the subsequent rapid precipitation of alumina trihydrate caused losses in alumina recovery.

Jan 1, 1965

By D. K. Deardorff

The hafnium-vanadium phase diagram was constructed within an estimated accuracy of ± 10° C and ± 2 wt pct composition. Alloys for investigation were melted under an atmosphere of purified helium by nonconsumable tungsten-electrode arc melting on a water-cooled copper hearth. Melting points were determined by optical pyrometer, and the remaining phase relationships were investigated by metallography, thermal analysis, and X-ray diffraction. The existence of a face-centered cubic intermetallic compound HfV2 (a = 7.38 A) was confirmed. A eutectic reaction occurred at 20 wt pct vanadium and 1,395° C to yield HfV2 and 8 solid solution. HfV2 melted incongruently by a peritectic reaction at 1,480° C, and the 3 solid solution decomposed eutectoidally at 1,165° C and 6 wt pct vanadium to yield HfV2 and a solid solution. The eutectoid, the eutectic, and the peritectic isotherms extended from 1 to 36.3 wt pct vanadium, from 8 to 36.3 wt pct vanadium, and from 26 to 89.5 wt pct vanadium, respectively. Terminal solid solubilities of hafnium in vanadium at 1,300° C and of vanadium in hafnium at 1,100° C determined to be about 3 and 1 wt pct, respectively.

Jan 1, 1965

By Edward W. Parsons

The explosive-anchored rockbolt was field tested in six mines where rock conditions varied from incompetent shale or mudstone through fairly soft sand-stone to firm sandy shales. The purpose of the testing was to document, under a wide variety of conditions and in comparison to other rockbolt anchors, the quality of the anchorage produced by the explosive-anchored bolt. In addition, the length, strength, and design of the explosive charge necessary to produce positive anchorage up to the yield strength of the weakest component of the bolt were determined. A l4-inch length beaded explosive charge was found to be suitable, in general, in relatively weak strata, and the length can be reduced in more competent strata. Of the 127 explosive?-anchored bolts tested, 118 bolts produced an evaluated anchorage in excess of 17,000 pounds. Only 4 of 43 expansion-shell bolts and 4 of 14 wedge bolts produced anchorage this good. In preliminary tests, properly coupled explosive-anchored bolts did not ignite an explosive gas mixture. Some minor phases included in the investigation were as follows: (1) effect of explosive-anchored rockbolt on surrounding rock; (2) effect of time on anchored bolts based on torque tests; (3) effect of submersion in water on rockbolt anchorage; (4) pull tests to higher loads; and (5) ignition tests.

Jan 1, 1965

By R. C. Buehl

A pyrometallurgical process for recovering manganese from open-hearth furnace slags or low-grade manganiferous iron ores is described. The slag or ore is smelted in a blast furnace to produce spiegeleisen; the speigeleisen is then blown with air in a basic converter to give an oxide slag. This slag product contains 60 to 75 percent manganous oxide and may be considered a synthetic manganese ore. In the smelting operations coke rates for five test periods ranged from 3,255 to 4,130 lb per ton of spiegeleisen. The recovery of manganese in the spiegeleisen varied from 60 to 76 percent. Recovery increased to 83 percent when the open-hearth slag feed to the blast furnace was diluted with a high-? grade iron ore sinter to facilitate smelting. In blowing the spiegeleisen a cyclic procedure was developed that gave nearly 90 percent recovery of manganese in the slag product (synthetic ore) yet prevented excessive contamination of the slag by phosphorus and iron. The overall recovery of manganese was about 75 percent when iron ore sinter was used with the open-hearth slag in the smelting step. The metal remaining after oxidizing the manganese from the spiegeleisen contained approximately 3.5 percent phosphorus. It was refined in a basic converter by blowing with air in the presence of lime" A high--grade iron and a basic phosphate slag were produced.

Jan 1, 1965