Notes

NONFERROUS METALLURGY. II. Zirconium, Hafnium, Vanadium, Niobium, Tantalum, Chromium, Molybdenum, and Tungsten

“…Cheng (52) studied the factors affecting color formation and the properties of the complexes formed by zirconium and hafnium with xylenol orange and methylthymol blue. It was observed that zirconium formed (268) Lumogallion: Ta, Zr (6) Derivatives of 2,3,7-trihydroxy-6-fluorone: Study of reagents (201) Compounds containing , '-dihydroxyazo: Study of reagents (9) Phosphomolybdic acid: Study of conditions and/or reagents (256) Peroxide: Pyrochlore soils (22) Pyrogallol: Ti, Nb (181)', Ti (179)•, Be, BeO (115)', V (47); minerals and ores (279); complex alloys (110) Methyl violet: Study of reagent (221,222) 1-(2-Pyridylazo)-resorcinol: Nb, Ti, Zr (7) Pyrocatechol Violet : Study of reagents (19) 12-Molybdotantalic acid: Nb, Ti (102) s-Diphenylcarbazide: Study of reactions (178,294); Be (228); U, U oxides (119, 237); W, Mo, V (286); Nb, Ta, W (110); sapphire and ruby (56); diphenyl (190) EDTA, NTA, HEDTA, DCTA, DTPA: Study of absorption spectra (33) EDTA: Ores (25) 1,2-Diaminocyclohexanetetraacetic acid: Ores, refractories (248) Tribenzylamine: Study of conditions and/or interferences (86) Thioglycolic acid: Study of reactions (143) Thiocyanate: Study of interferences (116); W (219); U (119); Cr, W, V (286); steel (92); sea water (281) Diantipyrylmethane-thiocyanate: Steel (264) 8-Quinolinol: Study of conditions and/or interferences (171); U (192); nuclear reactor materials (75) Xylenol orange: U (38) Thioglycolic acid: Study of conditions and/or interferences (143) 8-Quinolinol-5-sulfonic acid: Alkaline earths, Ni, Cd, Al, Th, Mn, Cr (41) 8-Mercaptoquinoline: Study of conditions and/or interferences (170) 1,10-Phenanthroline: Study of conditions and/or interferences (109) 2-Amino-4-chlorobenzenethiolhydrochloride: Steel and cast iron (139) Chloroanilic acid: Study of conditions and/or interferences (158) Diethvldithiocarbamic acid: Study of conditions and/or interferences (103) 1-Mercaptopropionic acid: Study of reagent (42) Solochr...…”

“…Cerrai and Testa (49) determined zirconium after extraction with tri-ro-octylamine by using xylenol orange. Headridge and Dixon (110) first separated zirconium from niobium, tantalum, and tungsten by means of ion exchange and then determined it with xylenol orange. Olson and Margerum (207) studied the zirconium complexes with a related compound, semixylenol orange, and described a method for the determination of zirconium using this reagent.…”

“…Webb, Ashworth, and Hills (279) determined both niobium and tantalum with pyrogallol following a cupferron separation. Headridge and Dixon (110) used anion exchange resins and hydrochloric acid solutions to separate the constituents of complex alloys before determining the niobium spectrophotometrically with thiocyanate and the tantalum with pyrogallol.…”

“…Although it appears that spectrophotometric methods for the determination of chromium are somewhat less popular than they were in the past, some additional papers report the application of the s-diphenylcarbazide method for the determination of chromium in beryllium (223), uranium and uranium oxides (119, 237), diphenyl (190), and sapphire and ruby maser crystals (56). s-Diphenylcarbazide was also used by Witwit, Magee, and Wilson (286) for the determination of chromium following separation from tungsten, molybdenum, and vanadium by partition chromatography, and by Headridge and Dixon (110) following ion exchange separations from alloys containing niobium, tantalum, and tungsten. Zittel (294) found that exposure to -ray radiation introduces very little error into the s-diphenylcarbazide method for chromium.…”

Thorium content of primary standard grade ammonium hexanitratocerate: an optical emission spectrographic study

“…These investigators, too, found that the number of recrystallizations required to obtain high radiochemical purity depended on the purity of the starting material. The recommended procedures (3)(4)(5) for preparing the primary standard grade reagent do not incorporate these multiple recrystallization steps.…”