煤中无机矿物组分的溶出性及其对水煤浆流变特性的影响

用等离子体原子发射光谱考察了１４种不同变质程度煤中的无机矿物质在煤浆分散体系中的溶出性，并就其对浆体流变特性的影响进行了讨论。结果发现；煤中无机矿物质的溶出性视煤种和煤中矿物质含量的不同而有很大差异，而且，除个别煤熔出相当数量的铝离子外，其余煤在浆体分散体系中溶出的无机矿物离子均主要以钙出子为主，其次为镁，铁离子。     

Preparation and characterization of microwave-treated carboxymethyl chitin and carboxymethyl chitosan films for potential use in wound care application

CM-chitin and CM-chitosan films were successfully crosslinked by microwave treatment. Crosslinking of the microwave-treated CM-chitin films involved mainly the carboxylate and the secondary alcohol groups, while crosslinking of microwave-treated CM-chitosan films involved the carboxylate and the amino groups. In addition, the crystallinity of CM-chitin increased with increasing microwave treatment time, whereas an increase in the crystallinity of the microwave-treated CM-chitosan films was not observed. At a similar percentage of weight loss, the crosslinking of either CM-chitin or CM-chitosan films by microwave treatment required much less stringent condition when compared with the crosslinking by autoclave treatment. Based on both direct and indirect cytotoxicity assays, the cytotoxicity of the microwave-treated CM-chitin films was negative, while that of the microwave-treated CM-chitosan films was positive. Human fibroblasts adhered on the surface of microwave-treated CM-chitosan films much better than on the surface of microwave-treated CM-chitin films.     

黑液水煤浆主要矿物元素在炉内的迁移和沉积行为研究

为了研究黑液水煤浆的灰沉积机理，采用沿烟气行程从实验炉不同部位抽取空间灰粒和提取相应位置炉壁灰渣样相结合的方法，并与常规水煤浆相对比，研究了各主要矿物元素（Na、K、Si、Al、Fe、Ca）在烟气流中的迁移趋势和沉积特性。并且通过X射线衍射（XRD）和扫描电镜（SEM）等分析从微观角度进行了验证。结果表明，与常规水煤浆不同的是，Na、Si、Al的迁移和沉积是引起黑液水煤浆沾污结渣的主要矿物元素，灰沉积物中主要包括无水芒硝、霞石等低熔融温度富Na物相，而Fe的沉积是次要因素。     

煤沥青水浆的制备及影响规律的研究

以中温煤沥青为原料,经冷冻粉碎后制得具有一定粒径级配的煤沥青粉,加入适量分散剂和水在高速搅拌下制备煤沥青水浆.结果表明,JL-C01中裂乳化剂是制备煤沥青水浆的优良分散剂,在此基础上进一步考察了分散剂用量及浆体浓度对煤沥青成浆性、煤沥青水浆流变性及稳定性的影响.结果表明,最大成浆浓度为70％;在分散剂用量相同的条件下,...     

全温度段裂解提质对锡盟褐煤成浆特性的影响

通过对锡盟褐煤进行涵盖高、中、低完整温度段的裂解提质,研究了裂解过程对煤质特性、成浆浓度、浆体流变特性以及稳定性的影响。对锡盟褐煤在隔绝空气条件下裂解,测量不同浓度浆体的黏度,并对剪切速率和表观黏度进行拟合得到不同浆体不同浓度的流变特性曲线,根据国标规定方法测量浆体的实际浓度以及浆体稳定性。并从裂解过程中样品表面官能团和孔隙结构变化角度分析裂解对锡盟原煤及半焦成浆特性的作用机理。实验结果表明,裂解过程可以减少样品中的含氧官能团,降低其亲水性,有利于成浆浓度的提高,成浆浓度随裂解温度的升高呈现先增大后减小的变化趋势,但是裂解对浆体的稳定性有负面影响。随裂解温度的提高,含氧官能团的分解导致半焦的孔隙结构发生显著变化,平均孔径先减小后增大,比表面积和孔容积呈先增大后减小趋势。     

An investigation of a separation process involving liquid—water—coal systems

A liquid—liquid—solid separation procedure wherein a water—oil—coal—mineral matter slurry is allowed to come to equilibrium through mechanical agitation has for many years been applied to the separation of coal from mineral matter. The product is a black “cottage cheese”-like mass of agglomerated coal particles and oil suspended in the excess water which supports the dispersed mineral matter particles. A liquid “bridge” model was proposed by earlier investigators which is reviewed critically and used to estimate the free energy per unit area of the separation of coals of different ranks. Observations of the kinetics of the process suggest that the simple liquid “bridge” model is insufficient, probably due to the heterogeneous surfaces of the coal. An alternative model is proposed.     

Single-step microwave digestion with HNO(3) alone for determination of trace elements in coal by ICP spectrometry

A microwave digestion method with HNO₃ alone was conducted at a temperature as high as 250 °C for determination of 19 trace elements (Li, Be, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Cd, Cs, Ba, Hg, and Pb) in coal jointly by inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and flow injection ICP-MS (FI-ICP-MS). The validity of determination was assessed by using three standard coals, SRM 1632c, BCR 180, and SARM 19. It was found that the high-temperature digestion led to an extensive decomposition of the organic matrix and clay in coal, and no dissolved and solid carbon remained in the final solution after evaporation. Good recoveries were observed for all trace elements in three coals, with the exception of V, Rb, and Cs in high-ash SARM 19. Additionally, FI-ICP-MS combined with the present digestion without evaporation pretreatment was proved to be a rapid and efficient approach for determination of ultra-trace elements such as Se, Cd, and Hg in coal.     

原煤和黑液水煤浆燃烧特性的热分析对比研究

在热天平上进行黑液水煤浆和原煤的燃烧、热解实验,得到不同升温速率下的燃烧、热解特性曲线和碳转化率特征曲线。试验结果表明,黑液水煤浆中的钠及其化合物在燃烧过程中催化作用明显,并且黑液中有机物成分对燃烧起到一定促进作用。在20 ℃/min升温速率下黑液水煤浆和原煤的燃烧活化能分别为12.98 kJ/mol和106.59 kJ/mol,反映出黑液水煤浆比原煤有更好的着火特性。     

外加无机电解质对煤浆性质调控作用的研究

考察了数种无机电解质对煤浆分散体系流变特性的影响。结果发现，煤浆的流变特性不仅与电解质种类有关，还取决于煤质特征。某些煤适，适量的无机电解质可使浆体的屈报胀塑料转化为屈服假塑性。     

Yield Stress Measurement of Dense Pastes with Pipe Transport and Vane

Yield stress is a key rheological parameter of dense paste. Considering practical utility and to estimate the possible slipping flow, yield stress measurements were carried out using the curve extrapolation method and vane method with rheometer in both controlled shear stress (CSS) and controlled shear rate (CSR) model. All measured yield stresses show to increase exponentially with concentration in different scale. The vane method yield stresses are both higher than the extrapolation curve yield stress. For the coal slurry used in this paper, the extrapolation curve yield stress is lower by 17–30% than the dynamic yield stress that obtained under test model CSR. It indicates that wall slip exists in pipeline transportation; meanwhile wall slip can reduce transportation resistance of dense paste to some extent.     

壬基酚聚氧乙烯醚聚合度对水煤浆浆体性质的影响

研究了壬基酚聚氧乙烯醚型添加剂的聚合度对变质程度不同的8种煤所制得的水煤浆浆体性质的影响规律。结果表明,壬基酚聚氧乙烯醚添加剂的聚合度对于8种煤所制得的水煤浆的成浆性、流变性以及静态稳定性均有一定的影响,存在一最佳范围。研究还发现,用壬基酚聚氧乙烯醚型添加剂制备水煤浆时,该添加剂的作用与煤的分析基水分质量分数、丝质组分质量分数以及孔体积之间存在着相关性。     

分散剂分子结构特征对煤浆流变特性的影响

系统考察了具有不同分子结构特片系列分散剂对高浓度煤浆性质的影响。发现煤的成浆性、浆体的流变特性和稳定化作用与分散剂的分子结构特征密切相关。就本研究所涉及的分散剂种类和煤种而言，分散剂单体结构中多核芳烃结构所占比例较小时易于使浆体呈屈服假塑性，相反，则使浆体呈屈服胀塑性。分散剂单体的侧链结构对煤成浆性和浆体流变性的影响不很突出，而分散剂的第二单体结构的影响却非常显著。结果还同时表明，分散剂的高分散性能是导致浆体呈屈服胀塑性流体和弱化浆体稳定化作用的重要因素。     

中国不同变质程度煤制备水煤浆的性质研究

在相同的制浆条件下,以中国煤种资源数据库为依据,考察了24种不同地区、不同变质程度煤制备成水煤浆的成浆性、流变性及静态稳定性。结果表明,山西阳泉、山东淄博石谷、河北下花园等煤种适宜制浆,这些煤的浆体质量分数均可达到66%以上,浆体呈假塑性流体,且煤浆产生软沉淀的静态稳定性均在15 d以上;山西潞安石圪节、安徽淮南、淮北石台等煤成浆性较好,稳定性在7 d左右,浆体呈胀塑性流体;山东枣庄八一、甘肃靖远红会、河南鹤壁等煤可达到较高的煤浆质量分数,浆体流变性及稳定性均较差,其他的煤则不适宜用于制备水煤浆。     

水煤浆燃烧炉内固体残留物的微观分析

以不同特性煤浆的炉内燃烧固体残留物为研究对象，对取自炉内不同部位及沉积于硅碳棒和灰污探针上的典型燃烧灰的化学成分、矿物组成、元素分布及微观结构等进行分析研究。结果表明，水煤浆灰样中含Al、Fe、Ca的化合物和矿物的质量分数高于黑液浆，Na、K、S、Cl的情况与此相反。Fe的富集是造成水煤浆沾污结渣的根本原因。Na和Fe是引起黑液浆沾污结渣的主要矿物元素，Na的作用比Fe更大。黑液浆灰样中含有大量的霞石和硫酸钠等低熔融温度富钠化合物，Na是引起沾污结渣的根源。微观分析结果与实际燃烧状况是一致的，黑液浆结渣特性强于水煤浆，并且二者的灰沉积机理是不同的。     

天然气水合物浆体分解对其在垂直管中流动特性影响的研究

针对天然气水合物浆体开采提升过程中水合物分解的问题,采用Euler多相流模型以及Finite-Rate/Eddy-Dissipation模型对天然气水合物浆体垂直管输的固-液两相流动以及气-液-固三相流流动特性进行研究。结果表明,受天然气水合物分解产生的气体影响,天然气水合物颗粒的速度分布、体积浓度分布均随高度的变化呈现出波动-均匀-波动的规律;水合物分解对浆体管道运输具有减阻作用,并提出天然气水合物浆体分解工况下,其流动速度不应低于3m·s~(-1);通过对管道的阻力特性分析,拟合出水合物分解下的水力提升阻力损失与流速的关系式,为天然气水合物浆体管道的经济提升参数提供指导。     

阴离子型添加剂的分子结构特征对水煤浆浆体性质的影响

选用分子结构特征不同的三类共七种添加剂和变质程度不同的八种煤,对添加剂的分子结构特征与煤质及水煤浆浆体各性质间的匹配规律进行研究。结果表明,以多核芳烃为缩聚单体的磺酸盐类添加剂中甲基取代基的引入对煤的成浆性不利,但有利于浆体向塑性流体转变和静态稳定性的提高;苄基取代基的引入能提高分析基氧体积分数低的煤种的成浆性,但是其浆体的静态稳定性较差。富含极性含氧官能团且变质程度较低的煤种在使用磺化程度较高的腐植酸盐类添加剂制浆时,可以制备出较高定黏浓度的水煤浆。腐植酸类添加剂磺化度较高时改善了浆体的流变性。对于腐植酸类和木质素类添加剂,磺化度较高的添加剂有利于挥发分较高的煤种所制浆体的静态稳定性的提高。     

Pipeline transport of biomass

The cost of transporting wood chips by truck and by pipeline as a water slurry was determined. In a practical application of field delivery by truck of biomass to a pipeline inlet, the pipeline will only be economical at large capacity (>0.5 million dry t/yr for a one-way pipeline, and >1.25 million dry t/yr for a two-way pipeline that returns the carrier fluid to the pipeline inlet), and at medium to long distances (>75 km [one-way] and >470 km [two-way] at a capacity of 2 million dry t/yr). Mixed hardwood and softwood chips in western Canada rise in moisture level from about 50% to 67% when transported in water; the loss in lower heating value (LHV) would preclude the use of water slurry pipelines for direct combustion applications. The same chips, when transported in a heavy gas oil, take up as much as 50% oil by weight and result in a fuel that is >30% oil on mass basis and is about two-thirds oil on a thermal basis. Uptake of water by straw during slurry transport is so extreme that it has effectively no LHV. Pipeline-delivered biomass could be used in processes that do not produce contained water as a vapor, such as supercritical water gasification.     

混合煤制浆对水煤浆性质的影响

实验选用三种性能较差，不适宜制浆的煤作为原料煤，选用成浆性、稳定性或流变性较好的三种煤作为配煤进行混合煤制备水煤浆。实验结果表明，在相同的制浆条件下，加入成浆性、稳定性较好的煤种，使得水煤浆性质较差的煤成浆性、稳定性均有不同程度的提高，浆体流变性得到改善，煤浆粘度明显降低。根据配煤加入量的不同，煤的成浆浓度可提高约2%～3%，浆体稳定性增加，产生软沉淀的时间由1 d提高到10 d。加入成浆性较差的褐煤，亦可明显提高难制浆煤种的稳定性和改善浆体的流变性，使得浆体由胀塑性流体变为假塑性流体。煤的表面性质分析表明，配入表面性质差异较大的煤种，有利于改善难制浆煤种的水煤浆性质。     

不同水煤浆分散剂与煤之间的相互作用规律研究 Ⅴ. 煤在分散剂水溶液中的溶出离子及其对CWS性质的影响

通过原子吸收和等离子体原子发射光谱法，研究了6种不同分散剂对14种煤溶出Ca2+、Mg2+、Fe3+(Fe2+)、Al3+、SiO32－离子的影响。结果表明，煤中溶出高价离子的数量，主要取决于分散剂与高价离子间的相互作用特征，以及矿物质的种类和数量。煤在不同分散剂水溶液中溶出高价离子的多少，并不单纯与水煤浆（CWS）的流变性或煤的成浆性具有相关性。煤中矿物质对CWS性质的影响，是多种因素综合作用的结果，溶出离子的种类和数量只是其中的重要因素之一。     

煤的岩相显微组分对水煤浆性质的影响

通过对不同变质程度煤的岩相显微组分分析，考察了煤的岩相显微组分对水煤浆性质的影响。结果表明，在相近的灰分含量下，对于烟煤较高的镜质组、较低的丝质组含量有利于煤的成浆性和稳定性。从多元线性回归结果来看，镜质组和丝质组的含量对煤浆成浆性和流变性的影响较为明显，稳定组分的含量对水煤浆性质的影响较小。丝质组含量对稳定性作用明显，当煤中丝质组含量低于30%时，煤浆产生软沉淀的时间一般都在15d以上。煤的平均最大镜质组反射率与煤的成浆性具有较好的相关性，成浆性随煤的最大镜质组反射率增加而增加，因此可以用最大镜质组反射率来预测煤的成浆性。