水煤浆分散剂作用机理及常用分散剂种类

水煤浆成浆性、黏度、流变性及稳定性除了与煤质本身的性质存在匹配关系外,还与分散剂种类、结构及性能密不可分。在对水煤浆使用优势分析的基础上,详述了分散剂作用机理及制取水煤浆常用的萘系分散剂、木质素系分散剂、腐殖酸系分散剂及聚羧酸系分散剂的分子结构和各自在使用过程中的优缺点。同时指出了水煤浆使用方向,利用复配增效作用,提出了发展我国水煤浆技术的长远策略:研究开发新型水煤浆分散剂,并将其与其他分散剂复配,对水煤浆的进一步开发和应用有十分重要的意义,达到廉价、高效的目的。     

水煤浆分散剂的研究进展

对水煤浆工业中普遍使用的阴离子和非离子分散刑的种类作了介绍,简要概括了其分散机理。并对水煤浆分散剂的研究开发与工业应用前景作了展望。     

水煤浆添加剂的研究现状及发展趋势

介绍了分散剂、稳定剂、辅助剂等水煤浆添加剂的分类及研究现状,着重分析了对水煤浆性能影响较大的添加剂分散剂的研究现状。目前研究和应用较多的水煤浆分散剂主要有木质素系、萘系等,根据分散剂特点进行复配使用,可以在一定程度上提高成浆性能、降低成本。简单分析了水煤浆添加剂的发展方向,认为充分利用含油废水、焦化废水、印染废水等制备水煤浆添加剂是未来的发展趋势。     

木质素磺酸钠/萘系复配分散剂的性能

选择应用广泛的木质素磺酸钠(木钠)和萘系(萘磺酸甲醛缩合物,NNO)分散剂,探究单一分散剂以及木钠和NNO复配分散剂对水煤浆性能的影响.在此基础上,详细考察木钠和NNO复配分散剂的配比及其用量对水煤浆性能的影响,并研究了复配分散剂对不同煤种的成浆性能.结果表明:与单一分散剂相比,木钠和NNO合理的复配具有良好的协同作用,当木钠与NNO的质量比为7∶3、用量为干煤基的0.50%时,制备的水煤浆流动性和稳定性良好,黏度为490.16mPa·s,质量分数高达63.1%,各项性能均满足工业制浆要求且成本较低,同时该复配分散剂均适用于不同的煤种并能满足工业制浆要求.     

聚羧酸系分散剂的侧链结构对水煤浆性能的影响

合成了两种以丙烯酸和苯乙烯磺酸钠为主链,淀粉以及甲氧基聚乙二醇(MPEG600)分别为侧链的聚羧酸系分散剂,将两种分散剂用于制备水煤浆,考察聚羧酸系分散剂的侧链结构对水煤浆性能的影响。结果表明,以淀粉为侧链的PC-St分散剂具有较好的分散降粘能力,且当PC-St分散剂用量为0.45wt.%时,水煤浆的最大成浆可达66.5wt.%,且PC-St水煤浆的稳定性也高于PC600水煤浆。     

磺化萘酚甲醛/萘系复合水煤浆分散剂的性能

以2-萘酚、浓硫酸和甲醛为原料合成了磺化萘酚甲醛(NPF)水煤浆分散剂.首先探讨了分散剂的合成条件对其性能的影响并进行了性质分析;其次,通过NPF与萘系(NSF)分散剂进行复配改善了NSF的稳定性能.结果表明,当甲醛和2-萘酚的配比为0.86:1,聚合温度为130℃,反应时间为2h时分散剂性能最好.用此分散剂,在分散剂用量为0.5%,煤浆浓度为64%时,水煤浆黏度为463mPa·s,分散性能良好.萘系(NSF)水煤浆分散剂中NPF的掺杂量为20%时,水煤浆黏度降低了150mPa·s,7d后析水率下降1.07%,无硬沉淀出现,稳定性提升明显.     

新型腐植酸基水煤浆分散剂的合成与性能

以腐植酸为原料,通过磺甲基化和缩聚反应,合成了一种具有良好水溶性和较高分子量的新型腐植酸系水煤浆分散剂.改变亚硫酸钠及甲醛用量对所合成分散剂进行工艺优化,确定最佳用量分别为22%和40%.采用红外、热重及凝胶渗透色谱等分析方法对产物进行结构表征;根据分散剂的不同添加量对水煤浆的黏度及稳定性进行分析,得出当水煤浆浓度为63%,分散剂用量为水煤浆总重量(干基煤)的0.6%时,水煤浆具有最低的表观黏度588mPa·s.     

腐植酸基分散剂的研究方向及展望

本文对水煤浆分散剂的各研究领域进行了初步的探讨,对国内水煤浆工业技术进行了简单介绍,讲解了各类水煤浆分散剂的分类以及使用方向和各类分散剂的优缺点。重点介绍了腐植酸及腐植酸基分散剂在水煤浆技术领域的研究现状和发展方向,并对腐植酸这类物质作为分散剂使用的优势进行了分析,为腐植酸工业应用提供了一定的发展方向。     

分散剂在煤水界面吸附的影响因素评述

分散剂在煤水界面的吸附特性直接影响水煤浆的工业应用,研究分散剂的吸附规律可揭示水煤浆体系的分散机理,并指导分散剂和煤种的匹配以及分散剂的分子设计。就影响分散剂在煤水界面吸附的因素包括煤的表面性质、分散剂的结构特征、分散剂的投加量和固含量等因素进行了讨论,认为这些影响因素主要通过改变分散剂在煤粒表面的吸附量、吸附强度和吸附层厚度来影响水煤浆的流变性和使用性。并对研究水煤浆体系吸附规律的实验手段做了展望。     

木质素系高效分散剂对水煤浆制浆性能的影响

以木质素磺酸钠为原料,通过磺化缩聚法合成一种木质素系水煤浆分散剂(GCL3S).水煤浆的流变性能测试表明,GCL3S对水煤浆的分散降黏能力优于萘磺酸盐甲醛缩合物系分散剂,GCL3S的分子量和磺化度是影响其对水煤浆分散降黏能力的主要因素,其中分子量的影响更为显著,适宜的分子量(特性黏度为6.84 mL/g～12.21 mL/g)和较高的磺化度(1.89 mmol/g)有利于提高GCL3S对水煤浆的分散降黏性能.采用Herschel-Bulkley模型对掺GCL3S的水煤浆浆体的流变曲线进行拟合,研究了GCL3S的分子量和磺化度对水煤浆流变性的影响.     

High-performance dispersant of coal–water slurry synthesized from wheat straw alkali lignin

Environmental concerns have stimulated interest in utilizing plant-derived materials in various industrial fields. The main objective of the present study was to synthesize a new type of high-performance lignin series dispersant of coal–water slurry (CWS) from wheat straw alkali lignin (WAL), and determine the affecting factors in the reaction and the application performance for CWS preparation. The experimental results showed that the inherent viscosity and the sulfonic group content of the modified wheat straw alkali lignin (MSL) are the key factors affecting its dispersing effect for CWS. In the reaction, the reactant mass concentration and the sulfonating agent amount were changed to obtain the MSL with different inherent viscosities and sulfonic group contents, and the MSL with intermediate inherent viscosity (6.0 ml/g) and higher sulfonic group content (1.80 mmol g^− 1) was found to have excellent dispersing effect for CWS. The MSL obtained from optimized process was used as dispersant for CWS preparation, the studies of the properties of CWS showed that MSL has similar dispersing effect with naphtalenesulfonate–formaldehyde condensate, and far better dispersing effect than lignosulphonate. Recently this kind of new dispersant has been applied in several power plants in China.     

不同水煤浆分散剂与煤之间的相互作用规律研究(Ⅵ)分散剂对水煤浆静态稳定性的影响

用1 4种不同变质程度的煤与1 0种分散剂成浆,研究了不同CWS的静态稳定性.结果表明,低阶的煤成浆稳定性主要取决于煤质特性,且煤的亲水性越强,CWS的稳定性越好.而高阶煤的成浆稳定性,主要依赖于分散剂的结构特征.分散剂对CWS稳定性的影响,主要取决于吸附在煤粒表面的分散剂间所产生的直接或间接的相互作用,当这种相互作用能使煤粒间在静态时形成大的三维网络结构时,则CWS具有很好的稳定性.建立了用流变曲线参数表示的CWS稳定系数模型,可用于描述不同流变特性CWS的静态稳定性.     

Influence of dispersants on coal-water slurry prepared from the solid residue of plasma pyrolysis of coal

This work presents the influence of dispersants on coal-water slurry (CWS), which was prepared from the solid residue of plasma pyrolysis of coal. The effects of dispersant type, solid concentration, dispersant content, and temperature on the rheological properties of CWS are examined. A suitable empirical model regarding the relation between viscosity and temperature is proposed. Through the sedimentation experiment of CWS, dispersants are found to significantly promote the stability of CWS.     

酶解木质素―磺化丙酮―甲醛缩聚物的合成与应用

以酶解木质素、亚硫酸氢钠、偏重亚硫酸氢钠、丙酮和甲醛为原料制备酶解木质素―磺化丙酮―甲醛缩聚物(E-LSAF),并作为水煤浆制备中的添加剂。通过测定E-LSAF的红外光谱、吸附量和ζ-电位的,探讨了添加E-LSAF对水煤浆体系的影响,并对比了E-LSAF、碱木质素―磺化丙酮―甲醛缩聚物(A-LSAF)和工业木素磺酸钠作为水煤浆添加剂对水煤浆分散稳定性的影响。E-LSAF作为添加剂应用于水煤浆的制备中,既可以有效地利用酶解木质素,又可降低水煤浆制备的成本,提高水煤浆的分散稳定性能。     

Effects of chemical structure on the properties of carboxylate-type copolymer dispersant for coal-water slurry

In this study, a series of carboxylate-type copolymer dispersants were prepared. The effects of chemical structures of the copolymer dispersants, including the molecular weight, kind, quantity and ratio of hydrophilic/hydrophobic groups, and side chain length, on the solid loading, apparent viscosity, zeta potential, rheological behavior, and stability of coal-water slurry (CWS) prepared from Dongtan, Yima, and Datong coals were systematically investigated. The dispersion performance of the copolymer can be improved by adjusting its chemical structures, and the dispersion mechanism was discussed. In addition, a high solid loading CWS with excellent stability toward settling can be achieved by means of the copolymer dispersant and carboxymethyl cellulose sodium salt (CMC-Na). Experiments have proved that the copolymer has the potential to be developed as a new high-effective dispersant for CWS. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

Evaluation of sulphonated acetone–formaldehyde (SAF) used in coal water slurries prepared from different coals

A new type of water-soluble polymer, sulphonated acetone–formaldehyde resin (SAF), was developed as dispersant for the preparation of highly-loaded coal water slurry (CWS). In this study, in order to evaluate the practical use in industry, the SAF and a naphthalene sulfonate formaldehyde condensate are used to prepare CWS using four Chinese coals with different coalification degrees. The evaluation of the properties of CWS shows that SAF has better ability in reducing CWS viscosity at lower dosage than naphthalene sulfonate formaldehyde condensate, and that the CWS prepared from SAF has excellent stability within 48 h and exhibits shear-thinning apparent viscosity/shear rate behavior at lower dosage. Based on the results, the SAF is an effective and promising dispersant for highly-loaded CWS.     

改性木质素磺酸盐水煤浆添加剂对神华煤制浆性能的影响

针对神华煤难以制成高浓度水煤浆的现状,采用Haake RV-Ⅰ流变仪等研究了改性木质素磺酸盐水煤浆添加剂(GCL3S)对神华煤水煤浆制浆性能的影响,GCL3S的质量分数为0.8%、制得的煤浆中煤质量分数达到62.63%,黏度可低至896 mPa.s,优于同等条件下萘系添加剂(FDN)的降黏效果,在接近中性条件下GCL3S的制浆性能最好,升高温度可以提高浆中煤的质量分数,对于用GCL3S制得的浆体,最佳搅拌时间是20~40 m in,其抗剪切性能明显优于FDN,GCL3S对煤浆的稳定时间为10 d,优于萘系添加剂。     

Evaluation of treated black liquor used as dispersant of concentrated coal-water slurry

The paper making waste liquor is a great water pollution source and much work has been done over the years to overcome this challenge. We present here a solution of black liquor used as dispersant of coal-water slurry (abbreviated as CWS) following chemical treatment. The treated black liquor (abbreviated as TBL) is used to prepare CWS for three bituminous coals, and the factors influencing its dispersing ability and the properties of CWS are investigated. The results show that the increasing sulfonating agent and formaldehyde dosage increase the sulfonic group content while reducing the molecular weight of TBL. The comparison with a naphthalene dispersant shows that TBL has a similar or better dispersing ability, and the large quantity of sulfonic groups engrafted in lignin molecules and the markedly increase of molecular weight are considered the key reason for the excellent performance of TBL. Moreover, the change of the molecular configuration from globular to flocculent in solution observed by TEM is also considered as an important reason for the excellent dispersing effect of TBL for CWS.     

复配分散剂与不同煤化程度煤成浆性能的研究

为了考察复配分散剂对不同煤化程度煤的成浆性能的影响,以木质素磺酸钠与萘磺酸钠复配分散剂对山西王坡煤(WP)、淮北朱仙庄煤(ZXZ)、内蒙古上湾煤(SW)3种不同煤化程度的煤样进行了制浆试验。结果表明:复配分散剂对上湾煤样所成浆的流动性和稳定性产生较大影响,但成浆浓度不高;对较高煤化程度煤样的成浆性提高效果明显,选用3号分散剂王坡煤的成浆浓度达到最大66.8%;朱仙庄煤选用4号分散剂可以制成流动性和稳定性较好的煤浆,其煤浆浓度达67.0%。木质素磺酸钠及萘磺酸复配分散剂的协同作用对不同煤化程度煤样成浆性的影响与煤的结构有关,此复配分散剂对煤化程度较高煤的成浆性提高较有利。