Kinetics of reactions of cyanide and reduced sulfur species to form thiocyanate

Technical Report · Tue Aug 01 00:00:00 EDT 1978

DOI:https://doi.org/10.2172/6166154· OSTI ID:6166154

Luthy, R. G.; Bruce, Jr., S. G.

Interactions of cyanide and reduced sulfur species in aqueous solution can produce thiocyanate. Kinetics of reaction of cyanide and polysulfide, and cyanide and thiosulfate were investigated. Initial rate kinetic data for reaction of cyanide and polysulfide showed the reaction is mixed order and that the order decreases from 1.91 to 1.18 as pH increases from 8.2 to 12; this was largely accounted for by a decrease in reaction order with respect to cyanide as pH increases above the pK/sub a/ for hydrogen cyanide. Catalysis and inhibition studies showed that high concentrations of ammonia were inhibitory and that coal char fines were catalytic. The rate of reaction of cyanide and polysulfide is approximately three or more orders of magnitude faster than reaction of cyanide and thiosulfate depending on pH value. A neutral or slightly alkaline solution containing on the order 10/sup -3/ M or more total sulfide can form polysulfide on exposure to oxygen, and in the presence of cyanide there should be reaction to yield thiocyanate. 7 figures, 3 tables.

• Research Organization: Carnegie-Mellon Univ., Pittsburgh, PA (USA). Dept. of Civil Engineering
• DOE Contract Number: EX-76-S-01-2496
• OSTI ID: 6166154
• Report Number(s): FE-2496-32
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AMMONIA
CARBONIC ACID DERIVATIVES
CATALYSIS
CHALCOGENIDES
CHARS
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
COAL FINES
CYANIDES
DATA
DATA FORMS
EXPERIMENTAL DATA
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
ISOLATED VALUES
KINETICS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PH VALUE
REACTION KINETICS
SULFIDES
SULFUR COMPOUNDS
THIOCYANATES
THIOSULFATES
YIELDS