通过分析磷石膏蒸压后样品的物相组成、相对结晶度、烘干抗压强度、微观形貌,研究了蒸压温度、保温时间、液固比、杂质等因素对磷石膏蒸压制备α-半水石膏的影响。结果表明：磷石膏蒸压后所得样品的烘干抗压强度与α-半水石膏晶体的相对结晶度呈正相关关系;在蒸压温度为130 ℃、保温时间为3~5 h、液固质量比为0.25条件下,所得α-半水石膏的相对结晶度高、烘干抗压强度大、晶体微观形貌完整且长径比小;磷石膏中的杂质会对蒸压样品的力学强度产生影响,将磷石膏水洗处理后,在蒸压温度为130 ℃、保温时间为3 h、液固质量比为0.25条件下,可制得2 h抗折强度为7.3 MPa、烘干抗压强度为32.8 MPa的α-半水石膏,该α-半水石膏符合JC/T 2038—2010《α型高强石膏》α30强度等级的要求。

By analyzing the phase composition,relative crystallinity,drying compressive strength and microscopic morphology of the samples after autoclaving of phosphogypsum,the effect of autoclavic temperature,holding time,liquid-solid ratio and impurities on the preparation of α hemihydrate phosphogypsum by autoclavic compaction was studied.The results showed that the drying compressive strength of the samples obtained after autoclaving of phosphogypsum was positively correlated with the relative crystallinity of α hemihydrate gypsum crystals.When the autoclaved temperature was 130 ℃,the holding time was 3~5 h,and the liquid-solid ratio was 0.25,the obtainedα-hemihydrate gypsum had high relative crystallinity,high drying com-pressive strength,complete crystal micromorphology and small aspect ratio.Impurities in phosphogypsum would affect the me-chanical strength of autoclaved samples.After the phosphogypsum was washed with water,the α hemihydrate gypsum with a 2 h flexural strength of 7.3 MPa and a drying compressive strength of 32.8 MPa could be prepared under the conditions of au-toclaved temperature of 130 ℃,holding time of 3 h and liquid-solid ratio of 0.25,which was in line with the requirement of α30 strength grade in JC/T 2038—2010“α-type high strength gypsum”.