Inorganic Chemicals Industry ›› 2022, Vol. 54 ›› Issue (10): 109-115.doi: 10.19964/j.issn.1006-4990.2021-0761

• Research & Development • Previous Articles     Next Articles

Preparation and characterization of anhydrous calcium sulfate whisker

QI Yuanhao1,2,3(),WU Jinxiu1,2,3(),LIU Zhaogang1,2,3,HU Yanhong1,2,3,FENG Fushan1,2,3,LI Jianfei1,2,3,WANG Xin1,2,3,LIU Conglin1,2,3   

  1. 1. School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010, China
    2. Green Extraction and Efficient Utilization of Light Rare Earth Resources Key Laboratory of Ministry of Education
    3. Inner Mongolia Autonomous Region Rare Earth Hydrometallurgy and Light Rare Earth Application Key Laboratory
  • Received:2021-12-20 Online:2022-10-10 Published:2022-11-03
  • Contact: WU Jinxiu E-mail:qyh15109117265@163.com;m13674773965@163.com

Abstract:

Calcium sulfate whiskers with high aspect ratio were prepared by hydrothermal method using ammonium sulfate wastewater produced in the production process of a rare earth plant as raw material and calcium chloride as calcium source. Firstly,the effects of reaction time,reaction temperature and aging time on the aspect ratio of calcium sulfate whisker were studied by orthogonal experiment to determine the optimal process conditions.Based on the optimal process conditions of orthogonal experiment,the effect of pH value on the morphology of calcium sulfate whiskers was studied.The surface morphology and phase of calcium sulfate whiskers were characterized and analyzed by scanning electron microscopy(SEM),X-ray diffraction(XRD), infrared analyzer(FT-IR) and thermogravimetric-differential thermal analyzer(TG-DSC).The results showed that the optimum preparation conditions of calcium sulfate whisker were reaction time of 5 h,reaction temperature of 140 °C,aging time of 4.5 h.When the pH value of the solution system was 1,pure anhydrous calcium sulfate whiskers were prepared,which had the best morphology and high aspect ratio.The average length was 117.44 μm and the average aspect ratio was 40.2.

Key words: ammonium sulfate wastewater, calcium sulfate whisker, hydrothermal method, aspect ratio

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