磷石膏煅烧过程中添加剂对其杂质和白度影响
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摘要
以氯化铵、氯化钠、连二亚硫酸钠为添加剂对磷石膏进行煅烧处理。对磷石膏进行球磨、筛分,考察了煅烧温度、煅烧时间、添加剂量对磷石膏中铁、有机碳的脱除情况及磷石膏白度的影响。采用白度仪、火焰原子吸收光谱仪、紫外分光光度计分析了处理前后磷石膏的白度、铁及有机碳含量的变化。结果表明:煅烧条件为温度475℃、时间2 h,随添加剂量增加,白度逐渐增大,加入NH4Cl 2%与磷石膏充分研磨进行煅烧,磷石膏白度由26.8%升高到87.12%,铁去除率达到96.61%,有机碳去除率为44.90%。磷石膏经过处理后白度提高,满足建材行业对石膏粉白度的要求(大于70%)。
Phosphogypsum was calcined with ammonium chloride, sodium chloride and sodium dithionite as additives.The effects of calcining temperature, calcining time and added amount on the removal of iron, organic carbon in phosphogypsum and the whiteness of phosphogypsum were investigated. The whiteness, iron and organic carbon contents of phosphogypsum before and after treatment were analyzed by whiteness meter, flame atomic absorption spectrometer and ultraviolet spectrophotometer. The results shows that the optimized process conditions were obtained as follows:calcining temperature 475 ℃, calcining time 2 h, NH4 Cl was selected as calcined additives and 2%, with the increase of dosage, the whiteness increases gradually,When adding 2% ammonium chloride to calcinate phosphogypsum,, whitening was improved from 26.8% to 87.12%, iron removal rate was96.61%, and the organic carbon removal rate was 44.90%. After treatment, the whiteness of phosphogypsum was improved to meet the requirements of building materials industry for the whiteness of gypsum powder(>70%).
Phosphogypsum was calcined with ammonium chloride, sodium chloride and sodium dithionite as additives.The effects of calcining temperature, calcining time and added amount on the removal of iron, organic carbon in phosphogypsum and the whiteness of phosphogypsum were investigated. The whiteness, iron and organic carbon contents of phosphogypsum before and after treatment were analyzed by whiteness meter, flame atomic absorption spectrometer and ultraviolet spectrophotometer. The results shows that the optimized process conditions were obtained as follows:calcining temperature 475 ℃, calcining time 2 h, NH4 Cl was selected as calcined additives and 2%, with the increase of dosage, the whiteness increases gradually,When adding 2% ammonium chloride to calcinate phosphogypsum,, whitening was improved from 26.8% to 87.12%, iron removal rate was96.61%, and the organic carbon removal rate was 44.90%. After treatment, the whiteness of phosphogypsum was improved to meet the requirements of building materials industry for the whiteness of gypsum powder(>70%).
引文
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[9]付彦林,李博,崔鹏.硬石膏煅烧-酸浸提增白技术的研究[J].应用化工,2012,41(1):16-18.
[2]REIJNDERS L.Cleaner phosphogypsum,coal combustion ashes and waste incineration ashes for application in building materials:a review[J].Building&Environment,2007,42(2):1036-1042.
[3]黄照昊,罗康碧,李沪萍.磷石膏中杂质种类及除杂方法研究综述[J].硅酸盐通报,2016,35(5):1504-1508.
[4]SINGH M.Treating waste phosphogypsum for cement and plaster manufacture[J].Cement&Concrete Research,2002,32(7):1033-1038.
[5]付全军,罗蜀峰,马先林,等.浸取中和法脱除磷石膏中杂质的研究[J].无机盐工业,2015,47(7):44-47.
[6]付彦林.含山硬石膏矿粉除杂脱色方法的研究[D].合肥:合肥工业大学,2012.
[7]戴瑾.铁染高岭土的漂白及煅烧增白工艺研究[D].厦门:厦门大学,2009.
[8]刁润丽,刘丹丹.平顶山高岭土的除铁增白实验研究[J].陶瓷学报,2016,37(4):400-403.
[9]付彦林,李博,崔鹏.硬石膏煅烧-酸浸提增白技术的研究[J].应用化工,2012,41(1):16-18.