Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Processing of spent hydrorefining catalysts by selective chlorination

Journal Article · · Metallurgical Transactions, B (Process Metallurgy); (United States)
DOI:https://doi.org/10.1007/BF02650069· OSTI ID:6967224
;  [1]
  1. Inst. National Polytechnique de Lorraine, Vandoeuvre (France)

Spent hydrorefining catalysts may contain 4 to 6 pct CoO and/or NiO, 8 to 16 pct MoO[sub 3], and up to 10 pct V[sub 2]O[sub 5], generally supported by alumina. Raw samples are roasted to eliminate C, S, and hydrocarbons contained in the spent catalysts. The optimum roasting temperature and time are 500 C and 7 hours. Chlorination of roasted samples with Cl[sub 2] + air, Cl[sub 2] + N[sub 2], and Cl[sub 2] + CO is investigated in order to recover the valuable metals selectively. Depending on the chlorination parameters, it is possible to recover more than 80 pct of the Ni and Co, about 95 pct of the Mo, and up to 80 pct of V compounds. The Co and Ni chlorides are obtained by leaching the chlorination residues with acidified water. The Mo and V chlorides and/or oxychlorides are obtained by selective condensation from the vapor phase. The chlorination of the catalyst support, Al[sub 2]O[sub 3], can be limited to less than about 5 pct. Besides the reaction temperature and time, the O[sub 2] partial pressure of the chlorinating gas mixture appears to be the key factor for the reaction's selectivity.

OSTI ID:
6967224
Journal Information:
Metallurgical Transactions, B (Process Metallurgy); (United States), Journal Name: Metallurgical Transactions, B (Process Metallurgy); (United States) Vol. 25:4; ISSN MTTBCR; ISSN 0360-2141
Country of Publication:
United States
Language:
English