【摘要】 通过土柱实验研究磷石膏改良剂对赤泥盐碱性和团聚体稳定性的影响。结果显示:随着淋溶时间的延长,赤泥渗滤液中盐碱性离子浓度降低,而SO₄^2-浓度增加;与对照组相比,添加磷石膏可显著降低赤泥中pH、电导率、可交换钠百分比、钠吸收比和交换态Na⁺含量;对照组和磷石膏改良赤泥团聚体的平均颗粒尺寸分别为155和193 nm。同时,同步辐射微CT扫描结果也证明经磷石膏改良的赤泥获得更大的团聚体尺寸和孔径。以上结果表明,磷石膏改良可以显著调控赤泥的盐碱性,同时改善赤泥团聚体的稳定性,为赤泥堆场的修复提供一种经济有效的途径。更多还原

【Abstract】 A column experiment was conducted to investigate the effect of phosphogypsum（PG） on the salinealkalinity, and aggregate stability of bauxite residue. Results showed that: with increasing leaching time, the concentrations of saline-alkali ions decreased while the SO₄^2- concentration increased in bauxite residue leachate; compared with CK（control group） treatment, pH, electric conductivity（EC）, exchangeable sodium percentage（ESP）, sodium absorption ratio（SAR）, and exchangeable Na⁺ content of bauxite residue were reduced following PG treatment; average particle sizes in aggregates following CK and PG treatments were determined to be 155 and 193 nm, respectively. SR-μCT test results also confirmed that bauxite residue following PG treatment acquired larger aggregates and larger pore diameter. These results indicate that the PG treatment could significantly modulate the saline-alkalinity, and simultaneously enhance aggregate stability of bauxite residue, which provides a facile approach to reclaim bauxite residue disposal areas.更多还原