摘要
以镍渣为原料,通过高温氧化分解、碱溶的方法溶出硅,用于制备层状结晶二硅酸钠,采用X-射线衍射(XRD)、傅里叶红外光谱仪(FT-IR)和扫描电镜(SEM)对制备的二硅酸钠进行了研究。结果表明,镍渣的氧化程度随着氧化温度的升高而增加,且细粒径镍渣更易被氧化。在氧化时间为1 h时,氧化温度由500℃升至1000℃,粗粒径镍渣的氧化率由24%增加到99.7%,而细粒径镍渣的氧化率则由41.7%增加到99.6%。XRD分析表明氧化过程中镍渣中的铁橄榄石相转变成赤铁矿和石英,在低温下生成的石英多为无定形状态。随着水热温度的增加,镍渣中硅铝的溶出率越大,但超过160℃后,由于铝硅反应生成不溶性的水合铝硅酸钠,溶出率反而略有下降。合成的二硅酸钠经XRD和SEM分析为δ-层状结晶二硅酸钠,其钙镁交换能力分别为366 mg/g和404 mg/g。
The silicon component was recovered by alkaline dissolution method from nickel slag after high-temperature oxidation to prepare layered crystalline sodium disilicate,which then was studied by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM).The results showed that the oxidation degree of the nickel slag increased with the increasing oxidation temperature,especially the fine particle size was beneficial to be oxidized.The oxidation degree of the coarse nickel slag bulit-up from 24%to 99.7%with the oxidation temperature increasing from500℃to 1000℃at 1 h,while the growth of the fine nickel slag was 41.7%to 99.6%.The XRD results of the oxidized nickel slag indicated that the fayalite in the nickel slag transformed to hematite and quartz during oxidation,while the quartz formed at low temperature was mostly amorphous.The dissolution rate of silicon and aluminum from the oxidized nickel slag grew up with the increase of the hydrothermal temperature,but the dissolution rate slightly decreased when the temperature exceeding160℃due to the reaction of aluminum and silicon to form insoluble hydrated aluminosilicate.The synthesized sodium disilicate was confirmed asδ-layered crystalline sodium disilicate by the analysis of XRD and SEM,with a calcium-magnesium exchange capacity of 366 mg/g and 404 mg/g,respectively.
作者
宋西珍
盛广宏
马研
王诗生
SONG Xizhen;SHENG Guanghong;MA Yan;WANG Shisheng(School of Energy and Environment,Anhui University of Technology,Ma'anshan 243002,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2019年第12期39-44,共6页
Environmental Science & Technology
基金
安徽省高校自然科学研究项目(KJ2018A0056)。
关键词
镍渣
高温氧化
碱溶
层状结晶二硅酸钠
nickel slag
high temperature oxidation
alkali dissolution
layered crystalline sodium disilicate
