Record Display for the EPA National Library Catalog


OLS Field Name OLS Field Data
Main Title Rate of Crystallization of Calcium Sulfate in Sulfite Liquor in the Presence of Seeding (Skorost Kristallizatsii Sulfata Kaltsiya v Sulfitnom Shcheloke v Prisutstvii Zatravki).
Author Sibirtsev, Yu. A. ; Sapotnitskii., S. A. ;
CORP Author Environmental Protection Agency, Research Triangle Park, N.C. Translation Services Section.
Year Published 1970
Report Number EPA-TR-76-115;
Stock Number PB-254 556-T
Additional Subjects Crystallization ; Calcium sulfates ; Solutions ; Supersaturation ; Translations ; USSR ;
Library Call Number Additional Info Location Last
NTIS  PB-254 556-T Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. 06/23/1988
Collation 7p
Sulfite liquor, obtained during boiling with acid and containing not only a calcium, but also a mixed calcium-sodium base, after preliminary concentration by evaporation is a supersaturated solution of calcium sulfate. Independently of the degree of replacement of the calcium ion with a sodium ion in boiling acid during the two-step method used in industry involving the neutralization of the liquor by milk of lime and ammonia, the solubility curve of calcium sulfate passes through a minimum corresponding to a pH value of 3.5 for the liquor. Upon introduction of a seeding of gypsum crystal into the calcium sulfite liquor, the supersaturation of the solution may be decreased to a significant degree. The effect of the indicated parameters on the rate of crystallization of calcium sulfate was investigated for sulfite liquors of the Kotlasskiy (calcium base) and the Solikamskiy (calcium-sodium base) cellulose-paper combines.