草酸钠对半水硫酸钙晶体稳定性的影响  

Effect of sodium oxalate on stability of calcium sulfate hemihydrate crystal

作　　者：李正 胡蒙 窦焰 崔鹏 沈浩[2] 郑之银[2] 刘荣[2] LI Zheng;HU Meng;DOU Yan;CUI Peng;SHEN Hao;ZHENG Zhiyin;LIU Rong(School of Chemistry and Chemical Engineer,Hefei University of Technology,Hefei 230009,China;Anhui Liuguo Limited Liability Company)

机构地区：[1]合肥工业大学化学与化工学院,安徽合肥230009 [2]安徽六国化工股份有限公司

出　　处：《无机盐工业》2022年第1期62-65,90,共5页Inorganic Chemicals Industry

摘　　要：以半水硫酸钙为原料、草酸钠为稳定剂,在反应温度为100℃、反应时间为20 min条件下,考察添加草酸钠对于半水硫酸钙保持稳定性的影响。采用XRD、TG和离子束切割晶体结合SEM-Mapping等手段对产物进行表征。实验结果表明:随着草酸钠添加量的增加,半水硫酸钙稳定时间不断延长,在草酸钠添加量(质量分数)为2.5%时,半水硫酸钙稳定时间最长,达到120 min。表征结果证明了CaC_(2)O_(4)·H_(2)O完全包覆半水硫酸钙,其作用机制是由于草酸钠在水中电离出C_(2)O_(4)^(2-)与Ca^(2+)发生沉淀反应,在半水硫酸钙表面生成CaC_(2)O_(4)·H_(2)O沉淀,从而提高了半水硫酸钙在水中的稳定性。Calcium sulfate hemihydrate used as raw material and sodium oxalate used as stabilizer,under the conditions of reaction temperature of 100℃and reaction time of 20 minutes,the effect of sodium oxalate on the stability of calcium sulfate hemihydrate was investigated.The products were characterized by XRD,TG,ion beam cutting and SEM mapping.The experimental result implied that with the increase of sodium oxalate addition,the stability time of calcium sulfate hemihydrate was continuously extended.When the addition amount of sodium oxalate was 2.5%,the stability time of calcium sulfate hemihydrate reached 120 min which was the longest.The characterization results showed that CaC_(2)O_(4)·H_(2)O completely covered calcium sulfate hemihydrate,and its mechanism was that sodium oxalate ionized C_(2)O_(4)^(2-)in water and precipitated with Ca^(2+)to form CaC_(2)O_(4)·H_(2)O precipitation on the surface of calcium sulfate hemihydrate,so as to improve the stability of calcium sulfate hemihydrate in water.

关 键 词：半水硫酸钙 草酸钠 化学沉淀 形貌 水化 

分 类 号：TQ132.32[化学工程—无机化工]