柠檬酸对固化硼废弃物性能的影响

Effect of Citric Acid on Properties of Solidified Boron Waste

目的研究柠檬酸改善固化硼废弃物性能的作用.方法测试柠檬酸对固化硼废弃试样抗压强度和凝结时间的影响,用电镜扫描观察掺入柠檬酸前后微观结构的变化,并用XRD分析其水化产物.结果当柠檬酸掺量为1.0%时,试样的3 d和28 d抗压强度达到最大值,分别为17 MPa和47 MPa,柠檬酸掺量在0.4%~1.0%时,对凝结时间影响较为显著.微观分析发现,掺入柠檬酸的硫氧镁水泥试样有较多的针柱状的5·1·7相晶体产生而没有Mg(OH)2晶体,且5·1·7相峰值强于未掺入柠檬酸的试样中的3·1·8相峰值.结论固化硼废弃物试样的3 d和28 d抗压强度随柠檬酸掺量的增加先增加后减小,在掺量为1.0%时最高,浆体的凝结时间呈逐渐延长的趋势.

The modification effect of citric acid on solidified boron waste is studied to improve the performance of solidified boron waste.The effect of citric acid on the compressive strength and setting time of solidified boron waste samples was test.The microstructure changes of solidified boron waste simples with before and after the incorporation of citric acid was observed by electron microscopy,and the hydration products of them were analyzed by XRD.When the content of citric acid is 1.0%,the compressive strength of the cured samples reaches 17 MPa and 47 MPa respectively for the setting time 3 d and 28 d,and the citric acid content is between 0.4%and 1.0%,which has a significant effect on the setting time.More needle-shaped 5·1·7 phase crystals found is found in the sample of bismuth oxysulfate cement with citric acid by microscopic analysis,but no Mg(OH)2 crystal.The peak of 5·1·7 phase is stronger than that of the 3·1·8 phase in the sample without citric acid.With the increase of citric acid content,the compressive strength of the cured boron waste samples for the setting time 3 d and 28 d increases first and then decreases,and the highest is observed when the dosage is 1.0%.The setting time of the slurry gradually extends.