Solubility of stibnite in hydrogen sulfide solutions, speciation, and equilibrium constants, from 25 to 350°C

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

7

Scientific paper

Solubility of stibnite (Sb 2 S 3 ) was measured in aqueous hydrogen sulfide solutions as a function of pH and total free sulfur (TFS) concentrations at 25, 90, 200, 275, and 350°C and at saturated vapor pressures. At 25 and 90°C and TFS 0.01 molal solubility is controlled by the thioantimonite complexes H 2 Sb 2 S o 4 , HSb 2 S - 4 , Sb 2 S 2- 4 (and polymers of the general composition H 2-x Sb 2n S x- 3n+1 ). At higher temperatures the hydroxothioantimonite complex Sb 2 S 2 (OH) 0 2 (or polymers of composition Sb 2n S 3n-1 (OH) 0 2 ) becomes dominant. Polymerization due to condensation reactions yields long chains made up of trigonal-pyramidal SbS 3 -groups (and SbS 2 OH-groups). Equilibrium constants were derived for the dimers. The transition from thioantimonites to the hydroxothioantimonite species at approximately 120°C is endothermic and is entirely driven by a gain in entropy. Stibnite solubility calculated for some geothermal fluids indicate that these fluids are undersaturated in Sb if stibnite is the solid equilibrium phase. At high temperatures (>100°C) precipitation of stibnite from ore fluids can occur in response to conductive cooling, while at low temperatures, where thioantimonites dominate, acidification of the fluid ( e.g. due to oxidation of H 2 S) is the more likely mechanism. Precipitation of stibnite from fluids containing hydroxothioantimonite consumes H 2 S and may thus trigger precipitation of other metals carried as sulfide complexes, e.g. Au(HS) - 2 .

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Solubility of stibnite in hydrogen sulfide solutions, speciation, and equilibrium constants, from 25 to 350°C does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Solubility of stibnite in hydrogen sulfide solutions, speciation, and equilibrium constants, from 25 to 350°C, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solubility of stibnite in hydrogen sulfide solutions, speciation, and equilibrium constants, from 25 to 350°C will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1756808

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.