Accession Number : AD0697068

Title :   ANALYTICAL TECHNIQUES FOR THE COMPOSITIONAL ANALYSIS OF REFRACTORY METALS AND COMPOUNDS.

Descriptive Note : Summary technical rept. 1 Apr 67-31 Dec 68,

Corporate Author : LEDOUX AND CO INC TEANECK N J

Personal Author(s) : Kallmann,S. ; Hobart,E. ; Conradi,R. ; Kazanjian,B. ; Wieland,J.

Report Date : OCT 1969

Pagination or Media Count : 21

Abstract : The report summarizes research aimed at devising and applying analytical chemical methods to refractory materials of interest to the Air Force. A simplified version of effluent gas analysis was investigated for application to a variety of refractory carbides. Experimental difficulties led to abandonment of the approach. A new method for determining nitrogen in refractory metals was devised and applied to various samples. Refractory metals were found to be dissolved readily by a mixture of HF-H3PO4 and K2Cr2O7. The nitrogen in such samples is converted to ammonium salts, readily distilled and measured with good sensitivity by the indophenol blue photometric method. The sensitivity of the dithiol method for determining tungsten and molybdenum in niobium and tantalum has been improved by use of a preliminary solvent extraction procedure to remove the bulk of tantalum or niobium from large samples. A modified counter-current extraction technique using the 6M HC1-2.4M HF and methyl isobutyl ketone system has been devised for determining as little as 5 ppm of tungsten in molybdenum. A new gravimetric system for determining major quantities of cobalt has been divised. Cobalt oxalate (CoC2O4.2H2O) is easily precipitated and dried to a constant composition containing 32.22% of cobalt. This technique is simpler and more accurate than the conventional electrolytic method. (Author)

Descriptors :   (*REFRACTORY MATERIALS, *CHEMICAL ANALYSIS), (*REFRACTORY METALS, CHEMICAL ANALYSIS), REFRACTORY METALS, REFRACTORY METAL ALLOYS, GAS ANALYSIS, CARBIDES, NITROGEN, GRAVIMETRIC ANALYSIS, TUNGSTEN, MOLYBDENUM, COBALT

Subject Categories : Inorganic Chemistry
      Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE