摘要
用水氯镁石为原料,氢氧化钠为沉淀剂,常压下合成氢氧化镁,在不加入任何改性剂的条件下,对反应后的料浆进行水热处理,并用扫描电镜(SEM)、X射线衍射仪(XRD)和激光粒度仪表征所得产品的形貌、结构及粒度分布,主要考察了水热反应时间和水热反应温度对氢氧化镁产品的影响.结果表明:在120℃水热4h条件下的过滤速率是未经水热条件下过滤速率的8倍,在200℃水热4h条件下的过滤速率是未经水热条件下过滤速率的13倍;在200℃,水热反应6h时所得的粒度分布已达到最佳分布状态;随着反应时间和水热温度的增加,晶体的生长方向有所改变,所得产物团聚现象不再明显,形貌也由无规则片状结构转化为规则的六角片状结构,氢氧化镁薄片的边界越来越清晰,厚度也逐渐增加.
With bischofite as raw materials and sodium hydroxide as precipitant,magnesium hydroxide was prepared under the normal pressure.We Mainly studied the influence of the hydrothermal reaction time and temperature on the magnesium hydroxide under the conditions of no modifier by taking hydro-thermal treatment of the slurry and using scanning electron microscope,X-ray diffractometer,laser particle analyzer to characteristic the products from morphology,structure and size distribution.The results showed that the filtration rate at 120℃in hydrothermal condition for 4 hours was eight times than that without hydrothermal condition and the filtration rate at 200℃in hydrothermal condition for 4 hours was thirteen times than that without hydrothermal condition.The size distribution at 200℃in hydrothermal condition for 6 hours achieved the best distribution state.As the reaction time and hydrothermal water temperature increasing,the growth direction of crystal changed,the agglomeration of the product was not remarkable and the morphology of the product was transformed from a no rule sheet structure into a regular hexagonal sheet structure.The boundaries of magnesium hydroxide sheets became more and more clear and the thickness increased gradually.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2011年第4期138-144,共7页
Materials Science and Technology
基金
中国科学院研究生科技创新资助项目(2008-34)
关键词
氢氧化镁
水热反应
单分散
六角片状
magnesium hydroxide
hydrothermal
monodispersed
hexagonal-plate
