摘要
赤泥作为氧化铝提炼过程中强碱性危险性副产品,在我国的利用率仅9.8%,亟需处置。本文采用自主研发的曝气装置对赤泥的CO_(2)曝气脱碱技术进行了研究,详细探讨了曝气时间、赤泥颗粒大小、CO_(2)通气速率和赤泥浆液固液比四方面对赤泥脱碱的影响。同时,借助扫描电镜分析了赤泥曝气前后的形貌特征。结果表明在常温常压反应体系下,当赤泥颗粒粒径为0.3 mm以下,CO_(2)通气速率200 mL/min、液固比为7、曝气时间为60 min时,可认为曝气已完全充分并且效果最好,此时赤泥浆液pH值为6.7。物相分析表明,曝气过程中含碱不稳定物相(钙霞石、硅铝酸钠)分解消耗,同时生成方解石(CaCO3)等难溶盐层包裹赤泥颗粒,驱动微观结构从松散细颗粒堆积向密实团聚体转变。处理后的赤泥可安全用于植被种植与土木工程领域。
As a strong alkaline hazardous by-product in the alumina refining process,the utilization rate of red mud in China is only 9.8%,which needs to be disposed urgently.In this paper,a self-developed aeration device was used to study the CO_(2) aeration and dealkalization technology of red mud.The effects of aeration time,red mud particle size,CO_(2) ventilation rate and solid-liquid ratio of red mud slurry on the dealkalization process are examined.The morphological characteristics of red mud before and after aeration were analyzed via scanning electron microscopy(SEM).Results indicate that under ambient temperature and pressure conditions,when the particle size of red mud is less than 0.3 mm,the CO_(2) ventilation rate is 200 mL/min,and the liquid-solid ratio is 7,when the aeration time reaches 60 minutes,it can be considered that aeration is fully sufficient and achieves the optimal effect,with the pH value of the red mud slurry measured at 6.7.Phase analysis indicates that during the aeration process,alkali-containing unstable phases(cancrinite,sodium aluminosilicate)are decomposed and consumed,while insoluble salt layers such as calcite(CaCO 3)are formed to wrap around red mud particles,driving the transformation of the microstructure from loose fine particle accumulation to dense aggregates.The treated red mud can be safely used in vegetation planting and civil engineering fields.
作者
穆川川
张伟
赵开红
姚爱玲
兰兆禹
崔林
Mu Chuanchuan;Zhang Wei;Zhao Kaihong;Yao Ailing;Lan Zhaoyu;Cui Lin(Shanxi Road&Bridge Group Xinzhou National Highway Construction Management Co.,Ltd.,Xinzhou 034000,China;China Communications Second Highway Engineering Bureau Dongmeng Engineering Co.,Ltd.,Xi'an 610000,China;Highway College,Chang'an University,Xi'an 610000,China;Shandong Electric Power Engineering Consulting Institute Co.,Ltd.,Jinan 250000,China;School of Science,Chang'an University,Xi'an 610000,China)
出处
《轻金属》
2025年第10期41-48,共8页
Light Metals
基金
山西路桥集团重点科研项目(水泥-赤泥基材料综合路用性能与推广应用研究(LQ0000000-F-TZ-2024-0281))。
关键词
拜耳法赤泥
曝气
碳酸化
脱碱
Bayer process red mud
aeration
carbonation
dealkalization
