Inorganic Chemicals Industry ›› 2022, Vol. 54 ›› Issue (1): 51-55.doi: 10.19964/j.issn.1006-4990.2021-0153

• Research & Development • Previous Articles     Next Articles

Study on process of preparing calcium sulfate whiskers from phosphate rock acid hydrolysis solution

MU Hong(),ZHOU Guiyun(),HU Haiyang   

  1. School of Chemical Engineering,Sichuan University,Chengdu 610065,China
  • Received:2021-03-16 Online:2022-01-10 Published:2022-03-14
  • Contact: ZHOU Guiyun E-mail:mh195632@163.com;zhouscu@126.com

Abstract:

Acid hydrolysis solution was prepared by decomposing of phosphate rock with hydrochloric acid firstly,and then sulfuric acid was added into the acid hydrolysis solution to prepare calcium sulfate whiskers.The effect of feeding time,stir-ring speed,sulfuric acid concentration,the amount ratio of sulfate to calcium ion,the mass fraction of calcium oxide and reac-tion temperature on the morphology of calcium sulfate and the aspect ratio of whiskers was investigated.The morphology of calcium sulfate was observed by scanning electron microscope and the SEM image of calcium sulfate was analyzed by Image-Pro-Plus to obtain the average aspect ratio of calcium sulfate whiskers.The optimal preparation process conditions for calcium sulfate whiskers obtained in the experiment were:Feeding time of 20 min,stirring speed of 350 r/min,sulfuric acid concentra-tion of 40%,reaction temperature of 70 ℃,sulfate radical to calcium ion molar ratio of 0.2,calcium oxide percentage of 5.5%. Under this process condition,calcium sulfate whiskers with a length-to-diameter ratio of 98.84 could be obtained,and the morphology was uniform.

Key words: hydrochloric acid, calcium sulfate whiskers, aspect ratio

CLC Number: