Photochemical separation of mercury isotopes. V. Further studies on the reaction of Hg²⁰²6(³P₁) atoms, photoexcited in natural mercury vapor, with hydrogen chloride

Journal Article · Tue Sep 01 00:00:00 EDT 1959 · Canadian Journal of Chemistry

DOI:https://doi.org/10.1139/v59-210· OSTI ID:4226110

McDowell, J. R.; McDonald, C. C.; Gunning, H. E.

A study was made of the reaction of Hg²⁰²( Pi) atoms, in natural mercury vapor (Hg^N), with hydrogen chloride under flow conditions at room temperature. Emphasis was placed on the effect of reaction parameters and mercury-recovery techniques on the Hg²⁰² content of the solid calomel formed in the reaction. For pure hydrogen chloride the Hg²⁰² content of the Calomel was found to be 39.9 plus or minus 0.3%, compared to the natural abundance of 29.8%. With 20 to 40 mole% of butadiene-1,3 in the hydrogen chloride, calomels containing 83 to 84% of Hg²⁰² were consistently obtained. The Hg²⁰² content of the calomel product was found to increase markedly when unsaturated hydrocarbons were added to the hydrogen chloride stream. The addends studied included butadiene -1,3, benzene, isoprene, acetylene, propylene, and ethylene in order of decreasing effectiveness. From steady-state calculations the effectiveness of the addend can be shown to be determined by the rate ratio, k₈/ k ₄. For the maximally enriching mixture of hydrogen chloride and butadiene, the effect of variations in lamp temperature and reaction pressure was studied. At lamp temperatures exceeding approximately 35 deg 'C, reduced enrichments were obtained owing to emission-line broadening. A progressive reduction in enrichment was also observed with substrate pressures greater than 25 mm, owing presumably to Lorentz-broadening of the hyperfine absorption contours of the Hg^N in the reaction cell. The Hg²⁰² content of the calomel product was determined by resonance radiation absorbiometry. The apparent Hg²⁰² abundances of the mercury recovered from the calomel product were found to depend strongly on the method used for isolating the enriched mercury from the calomel. Evidence was obtained for the occurrence of isotopically degradative exchange reactions during the recovery process. A recovery technique was developed which appeared to eliminate this exchange degradation.

• Research Organization: Univ. of Alberta, Edmonton, Can.
• Sponsoring Organization: USDOE
• NSA Number: NSA-13-023138
• OSTI ID: 4226110
• Journal Information: Canadian Journal of Chemistry, Vol. 37, Issue 9; Other Information: Orig. Receipt Date: 31-DEC-59; ISSN 0008-4042
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

07 ISOTOPE AND RADIATION SOURCES
ABSORPTION
ACETYLENES
BENZENE
BUTADIENE
EFFICIENCY
ENRICHMENT
ETHYLENE
HYDROCARBONS
HYDROCHLORIC ACID
ISOTOPE SEPARATION
ISOTOPIC EXCHANGE
MERCURY
MERCURY 202
MERCURY CHLORIDES
MERCURY ISOTOPES
PHOTONS
PRESSURE
PROPYLENE
QUANTITY RATIO
RADIATIONS
RECOVERY
RESONANCE
VAPORS