表面活性剂结构对细粒煤过滤脱水的影响及其机理研究

doi:10.3969/j.issn.1001-1803.2022.09.006

摘要/Abstract

摘要：

为降低细粒煤的水分,选取具有不同疏水基的聚氧乙烯型非离子表面活性剂AEO₉,LAE₉,OP₉和不同亲水基的AEO₄,AEO₇,AEO₉,AEO₁₅,AEO₂₀表面活性剂分别进行了细粒煤的过滤脱水试验。选取滤饼水分、过滤速度、滤饼比阻、滤饼渗透率为脱水效果评价指标。进行了表面张力、红外、润湿热、吸附量、Zeta电位的测试表征。细粒煤脱水实验结果表明,不同疏水基表面活性剂中的AEO₉表现较好的过滤脱水性能,不同亲水基的AEO系列表面活性剂中AEO₇具有较好的过滤脱水性能。针对表面活性剂AEO₇进行了细粒煤的过滤脱水的机理研究,发现在药剂用量为120 mg/L时,含氧官能团减弱程度最大,润湿热最低,表明煤表面的疏水性增强最显著,此时滤饼水分降低4.66%。同时滤液表面张力在AEO₇药剂用量超过120 mg/L几乎不再降低。吸附量测试结果表明表面活性剂用量在超过120 mg/L后,可能煤表面发生双层吸附使得煤表面变得亲水,从而减弱过滤脱水性能。

关键词: 细粒煤, 脱水, 表面活性剂, 疏水性

Abstract:

In order to reduce the moisture content of fine coal, both nonionic polyoxyethylene surfactants with different hydrophobic groups such as AEO₉, LAE₉, OP₉ and surfactants with different hydrophilic groups including AEO₄, AEO₇, AEO₉, AEO₁₅, and AEO₂₀ were selected for fine coal filtration dewatering experiments. The filter cake moisture, filter speed, filter cake specific resistance and permeability were used as the evaluation indexes for the dewatering effect. The surface tension, infrared spectroscopy, wetting heat, adsorption capacity and Zeta potential were employed. The results of the fine coal dewatering experiments show that AEO₉ among the surfactants with different hydrophobic groups has best performance, and AEO₇ among AEO series surfactants with different hydrophilic groups has best performance. The mechanism of the surfactant AEO₇ in the filtration and dewatering of fine coal was studied. The obtained results show that when the dosage of AEO₇ is 120 mg/L, the maximum amount of oxygen-containing functional groups have been decreased and the lowest wetting heat of the fine coal treated by AEO₇indicating that the hydrophobicity of the coal surface has significantly been enhanced. At this time, the moisture content of the filter cake is reduced by 4.66%. The surface tension of the filtrate solution hardly decreases when the dosage of AEO₇ agent exceeds 120 mg/L. The adsorption capacity results show that when the surfactant dosage exceeds 120 mg/L, it is possible that double-layer adsorption on the coal surface may make the coal surface hydrophilic, thereby weaken the filtration and dewatering performance.

Key words: fine coal, dewatering, surfactant, hydrophobicity

中图分类号:

TQ423

赵珂,刘生玉,张素红. 表面活性剂结构对细粒煤过滤脱水的影响及其机理研究[J]. 日用化学工业, 2022, 52(9): 951-959.

Zhao Ke,Liu Shengyu,Zhang Suhong. Effect of surfactant structure on filtration dewatering of fine coal and its mechanism research[J]. China Surfactant Detergent & Cosmetics, 2022, 52(9): 951-959.

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粒级/mm	产率/%	灰分/%	累计
粒级/mm	产率/%	灰分/%	产率/%	灰分/%
0.5~0.25	34	27.47	34	27.47
0.25~0.125	13.98	23.46	47.98	26.30
0.125~0.075	13.94	24.60	61.92	25.92
0.075~0.045	16.03	24.19	77.95	25.56
<0.045	22.05	25.17	100	25.48
合计	100	25.48

煤样	润湿热/（J/g）
原煤	-3.25
AEO₉+原煤	-1.659
LAE₉+原煤	-2.162
OP₉+原煤	-1.68

煤样	润湿热/（J/g）
原煤	-3.25
AEO₄+原煤	-1.876
AEO₇+原煤	-1.362
AEO₉+原煤	-1.659
AEO₁₅+原煤	-2.011
AEO₂₀+原煤	-1.744

煤样	润湿热/（J/g）
原煤	-3.25
20 mg/L-AEO₇+原煤	-1.362
120 mg/L- AEO₇+原煤	-1.116
160 mg/L- AEO₇+原煤	-1.327