Inorganic Chemicals Industry ›› 2024, Vol. 56 ›› Issue (8): 110-115.doi: 10.19964/j.issn.1006-4990.2023-0533

• Environment·Health·Safety • Previous Articles     Next Articles

Study on whitening of phosphogypsum by low⁃temperature calcination

TANG Xuemei(), WANG Meibo, XU Li, ZHANG Xujie, TAI Shijun, YI Xianmei, LIU Hongjuan, PAN Linyi   

  1. Guizhou Shengwei Research Institute of New Chemical Materials Co. ,Ltd. ,Guiyang 550014,China
  • Received:2023-11-09 Online:2024-08-10 Published:2024-09-26

Abstract:

Based on the fact that phosphogypsum whiteness had a crucial influence on the subsequent bulk utilization of phosphogypsum,in order to better utilize the phosphogypsum resources,maximize the value of phosphogypsum,and improve the phosphogypsum whiteness,the whitening of phosphogypsum by low⁃temperature calcination was studied.Phosphogypsum was sieved and calcined under the conditions of no additives,adding single additives(ammonium chloride,hydrogen peroxide,calcium hydroxide),and composite additives,and the results showed that the whitening effect of ammonium chloride in the single additives was better,and the whiteness of phosphogypsum was increased from 68.3% to 80.5% after adding ammonium chloride with the mass fraction of 1% and calcined at 460 ℃.At the calcination temperature of 400 ℃,using ammonium chloride with a mass fraction of 1% and calcium hydroxide with a mass fraction of 2.8% as a composite additive could increase the whiteness of phosphogypsum to 84.2%.In addition,under the condition that the whiteness of phosphogypsum was above 80.0%,the calcination temperature of phosphogypsum could be reduced to 350 ℃.This composite additive could effectively improve the whiteness of phosphogypsum and reduce energy consumption.

Key words: phosphogypsum, calcination, whitening, composite additive

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