An experimental study was carried out on fluoride removal from the wastewater after acid leaching process in one enterprise.In the experiment,zirconia was used in the 1st-stage reaction and amorphous aluminum hydroxide was adopted in the 2nd-stage reaction for fluoride removal,and effects of reaction temperature,reaction time and adding amount of zirconia-based reagent on the fluoride removal effect were explored.It is found that both higher temperature and longer reaction time can promote fluoride reduction effect of fluoride removing reagent.1st-stage reaction ran for 50 min at 75 ℃ with an addition of 50 g/L zirconia-based reagent,the fluoride reduction rate was up to 96％and fluoride mass concentration in the wastewater was reduced from 600 mg/L to 25 mg/L.After that,2nd-stage reaction at 70 ℃ ran for 60 min,by adding 5 g/L amorphous aluminum hydroxide,the fluoride mass concentration in the wastewater was down from 25 mg/L to 6.5 mg/L.It is shown that the residue left after fluoride removal process has a good crystal structure and obvious diffraction peak.XRD analysis shows that Na3AlF6 is the main component in the residue.
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