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Dissolution Modeling and Experimental Measurement of CaS‐H 2 O Binary System
Author(s) -
Zekker Ivar,
Tenno Toomas,
Selberg Aare,
Uiga Kalev
Publication year - 2011
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201180399
Subject(s) - chemistry , dissolution , solubility , retort , oil shale , sulfide , sulfur , inorganic chemistry , mineralogy , analytical chemistry (journal) , environmental chemistry , organic chemistry , waste management , engineering
CaS formed during the retorting process of oil shale has a hazardous influence on surface water quality. Interaction of retorted oil shale with water generates highly alkaline leachate with a high content of sulfur due to the CaS component. A theoretical model describing the behavior of solid calcium sulfide in contact with water was developed. The model was consistent with the measurements showing change in dissolution behavior when solid CaS remained in the solution. Experimental measurements of pH and concentrations of ions were carried out in oxygen‐free water at 25°C using CaS concentrations from 24.2–131.5 mg·L −1 (0.335–1.823 mmol/L). Analysis of pH and concentrations of ions in the solution and calculations by the developed model showed that the solubility of CaS was estimated as 125.0 mg·L −1 (1.733 mmol/L), and therefore the solubility product of CaS is 3.41×10 −10 (mo·L −1 ) 2 at a temperature of 25°C.