Preparation of α-Calcium Sulfate Hemihydrate from Phosphogypsum in CaCl2 Solution under Atmospheric Pressure

Bao Guo Ma; Xiao Hong Ru; Si Wen Lu; Kai Bo Zou

doi:10.4028/www.scientific.net/AMR.554-556.570

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HomeAdvanced Materials ResearchAdvanced Materials Research Vols. 554-556Preparation of α-Calcium Sulfate Hemihydrate from...

Preparation of α-Calcium Sulfate Hemihydrate from Phosphogypsum in CaCl₂ Solution under Atmospheric Pressure

Abstract:

With the growing demand of phosphoric fertilizer a great quantity of phosphogypsum (PG) was produced in China.To utilization of PG in an energy-saving way,the phase transition of PG from DH to α-HH in CaCl₂ solution under atmospheric pressure was conducted, the reaction time of phase transition was significantly shortened by higher reaction temperature and CaCl₂ content of the mixtures. The suitable temperature and CaCl₂ addition of the mixture were 95 °C and 24 wt.% respectively, morphology of the corresponding dehydration product phase is rod-like shape. Preparation of α-HH from PG in hot CaCl₂ solution at atmospheric pressure was based on dissolution- crystallization mechanism. The increasing addition of CaCl₂ in solution makes the solubility of CaSO₄ decrease due to the common ion effect.

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Advanced Materials Research (Volumes 554-556)

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570-574

DOI:

https://doi.org/10.4028/www.scientific.net/AMR.554-556.570

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Online since:

July 2012

Authors:

Bao Guo Ma, Xiao Hong Ru, Si Wen Lu, Kai Bo Zou

Keywords:

CaCl₂ Solution, Phosphogypsum, α-Calcium Sulfate Hemihydrate

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