Abstract The aqueous chemistry of micron-sized lignite particles has essential influences on the dispersion stability of water-lignite slurry. In this work, the adsorption behaviors of dissolved humics on lignite surface in lignite–water slurry were studied through batch adsorption experiments. The influences of adsorbed humics on the surface properties, particle size distribution and dispersion stability of lignite particles in water-lignite slurry were examined by advanced analysis techniques, EDLVO theory and settlement tests. The adsorption results indicate that the adsorption capacity of humics on lignite increases from 4.11 mg·g−1 to 8.25 mg·g−1 with the humics concentration increasing from 100 mg·L−1 to 200 mg·L−1. The adsorption process can be well described by the pseudo-second order kinetic model. The adsorbed humics significantly improves the hydrophilicity and electronegativity of lignite surface and reduces the apparent particle size of lignite. The EDLVO calculation and settlement tests reveal that the total interaction energy of the humics-adsorbed lignite particles at 18 nm of separation distance is enhanced from 0.85 × 10−17 J to 1.45 × 10−17 J with the initial humics concentration increasing from 100 mg·L−1 to 200 mg·L−1. The dispersion stability of micron-sized lignite particles is improved with humics adsorption on lignite surface.

中文翻译：

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褐煤-水浆中微米级褐煤颗粒的水性化学进一步探索：腐殖质吸附的影响

摘要 微米级褐煤颗粒的水性化学性质对水-褐煤浆的分散稳定性有重要影响。本工作通过批量吸附实验研究了溶解性腐殖质在褐煤-水浆中褐煤表面的吸附行为。通过先进的分析技术、EDLVO 理论和沉降试验研究了吸附的腐殖质对褐煤颗粒在水-褐煤浆中的表面性质、粒度分布和分散稳定性的影响。吸附结果表明腐殖质对褐煤的吸附量从4.11 mg·g-1增加到8.25 mg·g-1，腐殖质浓度从100 mg·L-1增加到200 mg·L-1。吸附过程可以用拟二级动力学模型很好地描述。吸附的腐殖质显着提高了褐煤表面的亲水性和电负性，降低了褐煤的表观粒径。EDLVO 计算和沉降测试表明，腐殖质吸附褐煤颗粒在 18 nm 分离距离处的总相互作用能从 0.85 × 10-17 J 提高到 1.45 × 10-17 J，初始腐殖质浓度从 100 mg 增加·L-1至200mg·L-1。褐煤表面腐殖质吸附提高了微米级褐煤颗粒的分散稳定性。85 × 10−17 J 到 1.45 × 10−17 J，初始腐殖质浓度从 100 mg·L−1 增加到 200 mg·L−1。褐煤表面腐殖质吸附提高了微米级褐煤颗粒的分散稳定性。85 × 10−17 J 到 1.45 × 10−17 J，初始腐殖质浓度从 100 mg·L−1 增加到 200 mg·L−1。褐煤表面腐殖质吸附提高了微米级褐煤颗粒的分散稳定性。