• Characterization of Alaska's coals

      Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1974)
      Coal characterization is a systematic determination of those properties of coal, or of its constituents, that affect its behavior when used. It will help in planning for recovery and use of the extensive Alaskan coal deposits, which have proven reserves of 130 billion tons. This estimate is of necessity based on widely scattered outcrops and meager drill hole data, and the reserves in the Cook Inlet region and the Northern Alaska field are considered to be several fold this figure.
    • Determination mercury in Alaskan coals by flameless atomic absorption

      Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1973)
      An oxygen combustion, double gold amalgamation system is constructed for the determination of mercury in Alaskan coals. Solutions have been found for certain problems in design and operation. The effect of operating variables have been thoroughly evaluated and analytical procedure is outlined. The system involves combustion of goal in an oxygen atmosphere and amalgamating mercury on gold coils. The amalgamated mercury is released by heating and measured in an atomic absorption cell.
    • Determination of molybdenum in geological materials

      Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1971-09)
      This paper will describe a method for the determination of molybdenum in geological materials. It is known that molybdenum as molybdate or phosphomolybdate ion can be extracted using the liquid ion exchanger, Aliquat 336 (methyl tricapryl ammonium chloride, available from General Mills, Inc. Kankakee, Ill.). Aliquat 336 has been used for analytical separation of gold, tungsten, and actinide-lanthanide elements.
    • The determination of titanium in titaniferous magnetite ores by atomic absorption spectrophotometry

      Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1972-03)
      Amos and Willis (1) first investigated the use of nitrous oxide for the determination of titanium. They found that the presence of HF and iron enhance the absorption of titanium. They recommended “much more extensive investigation before a practicing chemical analyst can determine this element in a routine fashion by atomic absorption.” Various authors (2, 3, 4, 5, 6) have investigated titanium by atomic absorption and have recommended a number of different procedures to remove interference. In attempting to analyze lithium metaborate fusions (7, 8) of titaniferous magnetite ores of Alaska by atomic absorption, it was found that the interferences are not completely removed by any single approach suggested in the literature. Silicon, iron and aluminum could vary widely between samples and an approach was needed that would completely eliminate interference effects of all these elements, without having to match the gross matrix composition of samples and standards.
    • Solvent extraction procedure for the determination of tungsten in ores

      Rao, P.D. (University of Alaska Mineral Industry Research Laboratory, 1970-11)
      Atomic absorption methods have not been widely used for the determination of tungsten in ores due to its low sensitivity in aqueous solutions (1). A method has now been developed for solvent extraction of tungsten, making rapid determination of tungsten at low concentrations possible. It was found that tungstates, when converted to phosphotungstates, can be effectively extracted into di-isobutyl ketone (2-6 dimethyl - 4 - heptanone) (DIBK) containing Aliquat 336 (methyl tricapryl ammonium chloride from General Mills). This system was effectively used for the extraction of gold from cyanide solutioins (2). Even in aqueous solutions, phospho-tungstates give greater sensitivity (37 µg/ml for 1% absorption) compared to simple tungstates (63 µg/ml for 1% absorption). Standard tungsten solutions for extraction studies were prepared by converting aqueous solutions of sodium tungstate to sodium phospho-tungstate by boiling with ortho phosphoric acid. A Perkin-Elmer Model 303 atomic absorption spectrophotometer was used with a nitrous oxide-acetylene flame at a wavelength of 4008.75 A.