摘要
煤化工废水成分复杂,处理困难。为了揭示煤化工废水中的典型组分吡啶对褐煤水煤浆流变性的影响规律,在添加0~1.3%的吡啶下,测试了褐煤水煤浆的浓度、黏度及浆体流体特性,采用单组分吸附和双组分吸附试验,通过对褐煤颗粒在吸附吡啶和分散剂前后的Zeta电位、接触角、表面官能团分布和数量的变化、亲疏水性强度的变化、颗粒分散团聚行为的变化情况进行分析研究,解释流变性变化的机理。结果表明,随着吡啶添加量增大,褐煤水煤浆的浓度变化不大,但黏度从1050 mPa·s增大到1250 mPa·s,浆体屈服应力从29 Pa增大到40.28 Pa,流动性指数从0.686增大到0.976,假塑性降低,吡啶吸附量最高达到10.5 mg/g,分散剂吸附量则从5 mg/g减小到3.5 mg/g。褐煤吸附分散剂后的Zeta电位绝对值与分散剂浓度成正比关系,而吡啶有所增大,但当分散剂和吡啶同时存在时,Zeta电位绝对值从27.9 mV增大到42 mV左右。吸附吡啶前后褐煤颗粒的接触角也从55.4°降到35.8°。主要是因为吡啶吸附在褐煤颗粒表面,使得Zeta电位减小,接触角降低,从而增强了表面负电性及静电排斥作用,且吡啶与分散剂形成竞争吸附,导致褐煤对分散剂的吸附量显著降低,从而引起分散剂对褐煤颗粒的分散降黏效果降低,黏度升高,表面官能团分析发现,褐煤吸附分散剂、吡啶,都是发生了物理吸附过程。双组分吸附时,由于吡啶的加入,也会使得原有的分散剂吸附褐煤颗粒所形成水化膜中的自由水量减少,从而使得褐煤水煤浆的黏度升高,假塑性降低。
Coal chemical waste water is often difficult to treat due to its complex composition. Pyridine is a typical component of coal chemical industry wastewater. In order to reveal the effect of pyridine, a typical component in coal chemical wastewater, on the rheological properties of lignite CWS,the concentration, viscosity and slurry fluid characteristics of lignite CWS were tested under the addition of 0-1.3% pyridine. The mechanism of the effect of pyridine on rheological properties of LWS was investigated by various characterization methods. Zeta potential, contact angle, distribution and quantity of surface functional groups, hydrophilic and hydrophobic properties of lignite particles before and after the adsorption of pyridine and dispersant were measured in the single-component adsorption and the two-component adsorption tests. Analytical studies are performed to explain the mechanisms of rheological changes. The results show that with the increase of pyridine addition, the concentration of LWS had little change, but the viscosity increased from 1 050 mPa·s to 1 250 mPa·s, and the yield stress increased from 29 Pa to 40.28 Pa. Besides, the fluidity index increased from 0.686 to 0.976 indicating that the pseudoplasticity decreased with the increase of pyridine addition. The maximum adsorption capacity of pyridine was 10.5 mg/g while the adsorption capacity of dispersant decreased from 5 to 3.5 mg/g. The absolute value of Zeta potential of lignite after the adsorption of dispersant was directly proportional to the concentration of dispersant, while the absolute value of Zeta potential of lignite had little increase with the increase of the concentration of pyridine. In addition, the absolute value of Zeta potential increased from 27.9 to 42 mV in the presence of both dispersant and pyridine. The contact angle of lignite particles before and after pyridine adsorption also decreased from 55.4° to 35.8°.The main reason is that the adsorption of pyridine on lignite particle surfaces reduced the Zeta potential an
作者
郑剑平
刘凯林
薛继峰
李高辉
张立峰
涂亚楠
ZHENG Jianping;LIU Kailin;XUE Jifeng;LI Gaohui;ZHANG Lifeng;TU Yanan(School of Chemical and Environmental Engineering,China University of Mining and Technology-Beijing,Beijing100083,China;China Coal Processing&Utilization Association,Beijing100013,China)
出处
《煤炭科学技术》
CAS
CSCD
北大核心
2022年第8期270-276,共7页
Coal Science and Technology
基金
国家自然科学基金面上资助项目(51974325)
中国矿业大学(北京)越崎杰出学者资助项目(2017JCB03)。
关键词
褐煤
水煤浆
吡啶
竞争吸附
流变性
lignite
coal water slurry
pyridine
competitive adsorption
rheology
