A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Effect of potassium sodium tartrate and sodium citrate on the preparation of alpha-calcium sulfate hemihydrate from flue gas desulfurization gypsum in a concentrated electrolyte solution
Flue gas desulfurization (FGD) gypsum mainly composed of calcium sulfate dihydrate (DU) was used as a raw material to obtain alpha-calcium snlfate hemihydrate (alpha-HH) through dehydration in a Ca-Mg-K-Cl-solution medium at 95 deg C under atmospheric pressure. The effects of potassium sodium tartrate and sodium citrate on the preparation of alpha-HH in the electrolyte solution were investigated. The results revealed that the addition of potassium sodium tartrate (1.0 x 10-2 - 2.5 X 10-2 M) decreased the dehydration rate of FGD gypsum and increased the length/width (l/w) ratio of alpha-HH crystals, which could yield unfavorable strength properties. Addition of sodium citrate (1.0 x 10-5 - 2.0 x 10-5 M) slightly increased the dehydration rate of FGD gypsum and decreased the l/w ratio of alpha-HH crystals, which could be beneficial to increase strength. However, it also led to a partial formation of anhydrite (AH) crystals. AH was also the only dehydration product when the concentration of sodium citrate increased to 1.0 x 10-4 M. Therefore, sodium citrate rather than potassium sodium tartrate could be used as an additive in Ca-Mg-K-Cl electrolyte solutions if alpha-HH with a shorter l/w ratio is the desired product from FGD gypsum dehydration. The concentration of sodium citrate should be properly controlled to reduce the formation of AH.
Effect of potassium sodium tartrate and sodium citrate on the preparation of alpha-calcium sulfate hemihydrate from flue gas desulfurization gypsum in a concentrated electrolyte solution
Flue gas desulfurization (FGD) gypsum mainly composed of calcium sulfate dihydrate (DU) was used as a raw material to obtain alpha-calcium snlfate hemihydrate (alpha-HH) through dehydration in a Ca-Mg-K-Cl-solution medium at 95 deg C under atmospheric pressure. The effects of potassium sodium tartrate and sodium citrate on the preparation of alpha-HH in the electrolyte solution were investigated. The results revealed that the addition of potassium sodium tartrate (1.0 x 10-2 - 2.5 X 10-2 M) decreased the dehydration rate of FGD gypsum and increased the length/width (l/w) ratio of alpha-HH crystals, which could yield unfavorable strength properties. Addition of sodium citrate (1.0 x 10-5 - 2.0 x 10-5 M) slightly increased the dehydration rate of FGD gypsum and decreased the l/w ratio of alpha-HH crystals, which could be beneficial to increase strength. However, it also led to a partial formation of anhydrite (AH) crystals. AH was also the only dehydration product when the concentration of sodium citrate increased to 1.0 x 10-4 M. Therefore, sodium citrate rather than potassium sodium tartrate could be used as an additive in Ca-Mg-K-Cl electrolyte solutions if alpha-HH with a shorter l/w ratio is the desired product from FGD gypsum dehydration. The concentration of sodium citrate should be properly controlled to reduce the formation of AH.
Effect of potassium sodium tartrate and sodium citrate on the preparation of alpha-calcium sulfate hemihydrate from flue gas desulfurization gypsum in a concentrated electrolyte solution
Einfluss von Kaliumnatriumtartrat und Natriumcitrat auf die Aufbereitung von alpha-Calciumsulfathemihydrat aus Rauchgasentschwefelungsgips in einer konzentrierten Elektrolytlösung
Shen, Zhuoxian (author) / Guan, Baohong (author) / Fu, Hailu (author) / Yang, Liuchun (author)
Journal of the American Ceramic Society ; 92 ; 2894-2899
2009
6 Seiten, 7 Bilder, 4 Tabellen, 19 Quellen
Article (Journal)
English
| European Patent Office | 2024
Effect of Sodium Citrate on the Hydration Capacity of Hemihydrate Calcium Sulfate Whiskers
| British Library Conference Proceedings | 2014
| British Library Conference Proceedings | 2014
| British Library Conference Proceedings | 2013
Process for continuous production of alpha-calcium sulfate hemihydrate and granular gypsum
| European Patent Office | 2023