EDTA对脱硫石膏制备α-半水石膏晶体生长的影响  

Effects of EDTA on crystal growth of α-hemihydrate gypsum prepared by flue gas desulphurization gypsum

作　　者：张稼祥 徐玲玲[1,2] ZHANG Jiaxiang;XU Lingling(College of Materials Science and Engineering,Nanjing Tech University,Nanjing 210009,China;Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM),Nanjing 210009,China)

机构地区：[1]南京工业大学材料科学与工程学院,江苏南京210009 [2]江苏先进生物与化学制造协同创新中心,江苏南京210009

出　　处：《南京工业大学学报（自然科学版）》2018年第2期90-94,131,共6页Journal of Nanjing Tech University(Natural Science Edition)

摘　　要：采用常压盐溶液法工艺以脱硫石膏为原料制备α-半水石膏,研究乙二胺四乙酸(EDTA)对脱水反应速率、产物晶体形貌的影响,并结合多种分析手段从微观角度对转晶机制进行探讨。结果表明:EDTA能显著降低脱硫石膏脱水反应速率,在0.2%~1.0%掺量下,脱水反应时间逐渐延长至4 h;EDTA对α-半水石膏晶体形貌改善作用明显,使之由细长的针棒状转变为短柱状,在1.0%掺量下晶体长径比约为1.5∶1;EDTA在晶体生长过程中会吸附在(111)晶面上,阻碍半水石膏晶体在c轴方向上的生长,但并未掺杂在产物石膏晶格中,不会改变晶体的晶型。Alpha hemihydrate gypsum was prepared from flue gas desulphurization(FGD)gypsum by hydrothermal method in salt solution at mospheric pressure.The effect of ethylene diamine tetraacetic acid(EDTA)on the dehydration rate and crystal morphology of the products was investigated,and the related mechanism of crystal modifying was discussed by various analysis means from the microscopic view.Results showed that the dehydration rate of FGD gypsum decreased with the incorporation of EDTA,and the dehydration time was gradually extended to 4 h under the dosage of EDTA from 0.2%to 1%.With the addition of EDTA,the morphology ofα-hemihydrate gypsum was modulated from acicular to short columnar crystals,and the crystal length diameter ratio was 1.5∶1 at the dosage of 1%.EDTA could absorb on the crystal face(111)of theα-hemihydrate gypsum,and inhibit the growth on the c-axis direction,but not dopein the gypsum lattice of the product,and the type of crystals was not affected.

关 键 词：脱硫石膏 Α半水石膏 EDTA 晶体形貌 

分 类 号：TQ177.3[化学工程—硅酸盐工业]