增钙煤矸石的结构特征及其活化机理研究

对原样煤矸石进行了系统分析.通过X射线衍射(XRD)和核磁共振(NMR)等测试方法对其活化过程的微观结构进行了分析.结果表明:在煤矸石的增钙煅烧过程中掺入适量的石膏和萤石等组分作为矿化剂时,有水硬性矿物生成.此状态的煤矸石中29Si峰产生了裂解和宽化,铝氧多面体结构由原样中的六配位为主转变为以四配位为主,这样的结构有利于改善煤矸石的活性.对煤矸石活化过程进行了力学性能试验.试验结果同样表明:各种增钙煅烧煤矸石的力学性能和微观结构的分析结果是相一致的.     

活化煤矸石基免烧砖胶凝性能的研究

对六盘水矿区煤矸石原粉组成进行分析,测定了煤矸石原粉和活化煤矸石粉制备免烧砖的胶凝性能,系统地研究了机械、热、化学及复合活化方式对原状煤矸石活性激发作用。研究表明,六盘水矿区煤矸石属于高铁高砂型煤矸石,活化煤矸石能够显著提高煤矸石基免烧砖的胶凝性能,复合活化效果优于单一活化方式,复合活化的煤矸石能够大幅度地提高免烧砖的胶凝性能,达到JC/T422-91(96)《非烧结普通黏土砖》MU15的标准。     

自燃煤矸石复合活化的正交试验研究

在对辽宁阜新高德矿自燃煤矸石进行了基本性质检测的基础上,采用物理和化学的激活方法,研究了自燃煤矸石胶结料的力学性能.物理研究表明该矸石易磨性较好;对以自燃煤矸石为主要材料的胶结料进行了正交试验研究,分析了矿粉、生石灰、二水石膏及水玻璃掺量对胶结料强度的影响.化学研究表明自燃煤矸石在复合激发剂的共同作用下,高掺量(74%)仍可配制出满足42.5强度等级的水泥.根据正交设计方差分析结果给出了胶结料的最佳配合比,为利用自燃煤矸石开发地聚物水泥提供了有益的技术参考.     

煤矸石少熟料水泥的研究

利用工业废渣研制少熟料水泥,是解决工业废渣资源化的有效措施。煤矸石是工业固体废弃物中排放和堆存量最大的一种,针对煤矸石的组成特点,通过正交试验研制较高标号的煤矸石少熟料水泥,并对其物理力学性能及耐久性做系统测试分析。研究表明,本文所研制的煤矸石少熟料水泥具有广泛的应用前景。     

The composition,morphology, and mechanical properties of ethylene propylene diene monomer‐encapsulated coal gangue powder/polypropylene composites

The ternary composites of coal gangue powder encapsulated by ethylene propylene diene monomer (EPDM) filled polypropylene (PP) were prepared to reduce the cost and control the microstructure aiming at high performance cost ratio materials. The result showed that EPDM can not only enhance the interaction between coal gangue powder and the matrix but also promote the dispersion of coal gangue powder. With the addition of coal gangue encapsulated by EPDM, the impact strength of composition dropped greatly, but it still kept about 11 kJ/m² when the content of encapsulated coal gangue powder is more than 18 wt%. The tensile strength and fracture toughness (w_e) also dropped with the addition of encapsulated coal gangue powder, but only a small drop occurred when the content of encapsulated coal gangue powder is less than 18 wt% and great drop emerged when the content is larger than 18 wt%. Compared with coal gangue powder/PP binary composition, the ternary compositions involve higher content of coal gangue powder but present better properties. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

萍乡废弃煤矸石理化特性及热活化性能研究

为研究不同种类煤矸石的理化特性及煅烧温度对其活化程度的影响,以萍乡废弃煤矸石不同矿区样A、样B、样C为研究对象,开展了XRD测试、物理性能试验、高温试验及力学性能试验,从理化特征、力学特征、表观特征等方面对煤矸石进行了基本性能及热活化性能分析。结果表明:不同种类煤矸石的理化特性不同,活性物质含量高的煤矸石活性较高;与样A相比,样B、样C更适合做填料,且样C具有更高的孔隙率、吸水性和抵抗风化破裂的能力。不同种类煤矸石的最佳煅烧温度略有差距,但都在800 ℃左右,未煅烧或未达到最佳煅烧温度的煤矸石活性较低,所制试件胶结较差,强度不高;最佳温度煅烧的煤矸石活性最高,所制试件胶结最好,强度最高。     

Preparation of SiC from acid‐leached coal gangue by carbothermal reduction

For the comprehensive utilization of coal gangue, acid‐leached coal gangue was used as silicon source and part of carbon source, low ash anthracite and degreasing cotton were added respectively as supplementary carbon source, SiC and SiC fiber were prepared by carbothermal reduction method accordingly. The results show that the main components in leached coal gangue are amorphous SiO₂ and carbon, which are suitable for the synthesis of SiC as raw materials. The synthesis temperature and holding time have important influence on the synthesis of SiC, and the optimum synthesis parameters for SiC are at 1550°C for 4 hours; under this condition, the yield of SiC is 78.27%, and the specific surface area is 6750 cm²/g. The results show that the resulting products are essentially composed of β‐SiC with a minor amount of α‐SiC. Besides, based on the carbon fiber transformation method, SiC fiber was prepared by using leached coal gangue and degreasing cotton as raw materials. Therefore, it can be concluded that leached coal gangue is a very effective and inexpensive source for preparing SiC, and more importantly, this work has important economic and social significance to realize waste recycling and control pollution.     

Improvement of Low-Rank Coal Flotation Based on the Enhancement of Wettability Difference between Organic Matter and Gangue

The main reason for low separation efficiency in low rank coal (LRC) flotation was the small wettability difference between organic matter and gangue. To improve LRC flotation response, a new method based on the expansion of wettability difference was proposed in this investigation. This method is that changing the adsorption liquid environment (adding Ca²⁺) to enhance the selective adsorption of surfactants on the surface of organic matter and increase its hydrophobicity, meanwhile applying ultrasonic desorption to remove the surfactants adsorbed on the gangue. The experiments were conducted on organic matter, gangue, and raw coal and combined with surfactant adsorption/desorption capacity, FTIR, and wetting heat determination to explore the underlying mechanism. The best flotation performance of raw coal was obtained when desorption time was 30 s. Surfactant adsorption results indicated that Ca²⁺ could promote the adsorption of surfactant on organic matter, but has insignificant effect on gangue. Under ultrasonic condition, surfactant capacity adsorbed on gangue decreased in the presence of Ca²⁺, but the addition of Ca²⁺ could inhibit surfactant desorption. However, in the raw coal, the surfactants could be removed from gangue surface under ultrasonic and Ca²⁺ because of the low proportion of gangue in raw coal and weaker adsorption strength of Ca²⁺ on gangue, as indicated by the ash reduction. Wetting heat results suggested that wettability difference between organic matter and gangue was expanded after ultrasonic treatment. This study may have some guiding significance for improving LRC flotation.     

回填矸石的粒度分布的分形结构与自燃特性的关系

应用分形几何理论对破碎矸石样品进行了粒度分析,研究表明,破碎矸石具有分形结构特征。通过矸石样品的H2O2氧化升温速率实验,研究了不同粒度分布的矸石自燃特性,并分析了自燃特性与粒度分布分维的关系,结果显示,矸石的氧化速率随着粒度分布分维的增大而增大。进而,提出了矸石氧化速率与粒度分布分维之间的数学定量关系式。     

煤矸石对水泥水化性能的影响

研究了煤矸石的种类、掺量以及化学激发剂对水泥水化性能的影响.煤矸石种类对水化性能有影响.化学激发剂促进煤矸石的早期水化,提高其反应程度.并对激发剂的激发机理做了探讨.     

Modification of ash flow properties of coal rich in calcium and iron by coal gangue addition

Flow property of coal ash and slag is an important parameter for slag tapping of entrained flow gasifier.The viscosity of slag with high contents of calcium and iron exhibits the behavior of a crystalline slag,of which viscosity sharply increases when temperature is lowered than temperature of critical viscosity(Tcv).The fluctuation in temperature near the Tcv can cause an accumulation of slag inside the gasifier.In order to prevent slag blockage,it is necessary to adjust the ash composition by additive to modify the flow property of coal rich in calcium and iron.Main components of coal gangue are Al2O3 and SiO2,which is a potential additive to modify the ash flow properties of these coals.In this work,we inves-tigated the ash flow properties of a typical coal rich in calcium and iron by adding coal gangue with dif-ferent SiO2/Al2O3 ratio.The results showed that the ash fusion temperatures (AFTs) firstly decreased,and then increased with increasing amount of coal gangue addition.Chemical composition of coal ash rich in calcium and iron moved from gehlenite primary phase to anorthite,quartz and corundum primary phases.The slags with coal gangue addition behaved as a glassy slag,of which the viscosity gradually increased as temperature decreased.Besides,a high SiO2/Al2O3 ratio of coal gangue was beneficial to modify the slag viscosity behavior.Addition of coal gangue with a high SiO2/Al2O3 ratio impeded forma-tion of crystalline phases during cooling.This work demonstrated that coal gangue addition was an effec-tive way to improve the ash flow properties of the coal rich in calcium and iron for the entrained flow gasifier.     

煤矸石骨料及其改性技术研究进展

煤矸石作为煤炭开采和洗煤过程中产生的废弃物,大量堆放会给生态环境带来巨大的压力,以煤矸石为骨料生产混凝土符合绿色可持续发展理念。煤矸石骨料具有孔隙率大、针片状颗粒含量高的特性,会对混凝土性能产生较大负面影响。本文简述了煤矸石骨料的基本物化特性,综述了煤矸石骨料对混凝土工作性能、力学性能、耐久性以及界面过渡区的影响;在此基础上,针对煤矸石骨料存在的缺陷,重点综述了煤矸石骨料改性技术(表面包覆、水玻璃改性、热活化和微生物矿化等技术)的研究现状,指出了每种改性技术目前存在的问题及解决方法,并对其在混凝土中的研究方向进行了展望,以期推动煤矸石骨料在混凝土的应用与发展。     

煤矸石改性聚丙烯性能研究

采用熔融共混制备了不同配比的聚丙烯（PP）／煤矸石（coal gangue）复合材料,与纯PP材料相对照,分别研究了复合材料的表面电阻率、体积电阻率,热变形温度以及拉伸强度,弹性模量、硬度等力学性能。结果表明：加入煤矸石能明显降低PP的表面电阻率和体积电阻率,起到较好的抗静电效果。当煤矸石含量约为20％时．复合材料的表面电阻率和体积电阻率均达到最小,分别为2．4×10^8Ω·cm和3．8×10^8Ω·cm,抗静电效果最佳;随着煤矸石填充量的增加,复合材料的力学性能呈现先下降后上升的趋势。材料的拉伸强度和断裂伸长率均在10％时下降至最小,而复合材料的硬度则随煤矸石用量的增加逐渐增强,其综合力学性能约在煤矸石含量为15％时达到最佳值;热变形温度随煤矸石用量的增加没有明显的下降。因此煤矸石含量约为15％的PP改性复合材料可用于生产静电逸散材料。     

石灰对煤矸石水泥砂浆性能影响研究

将铜川煤矸石进行热活化和机械活化后,加入石灰进行化学激发,掺入水泥砂浆中进行强度测试,对石灰和煤矸石掺量进行了实验研究,分析了石灰对煤矸石水泥砂浆的作用。结果表明,煤矸石和石灰掺入对水泥砂浆的强度具有较大的影响。煤矸石水泥砂浆的早期抗压和抗折强度均较低,但28 d强度随煤矸石和石灰用量增加出现先增加后降低的趋势。在煤矸石用量达到40%,石灰取代量为40%左右时,水泥砂浆抗压和抗折强度出现最大值。石灰的加入对煤矸石水泥砂浆的强度具有较大的提升作用,掺石灰后,煤矸石水泥砂浆28 d抗压强度提高约21%,抗折强度提高约31%。     

Reaction-bonded robust SiC ceramic membranes sintered at low temperature with coal gangue

Herein, we report an in-situ reaction-bonded SiC membrane sintered at low temperature using a solid waste (i.e. coal gangue) as the sintering aid to form strong neck connections. The effects of sintering temperature and coal gangue proportion on their properties regarding pore size, open porosity, bending strength and pure water permeability were investigated. The single-channel tubular SiC membrane sintered at 1300 °C with a coal gangue proportion of 12 wt% was optimal, exhibiting an average pore size of 2.78 μm, a open porosity of 47.08%, a bending strength of 34.01 ± 1.3 MPa and a high water permeability of 83967 L m⁻² h⁻¹ bar⁻¹. The membrane could completely reject D₅₀ = 0.87 μm SiC solids and presented a steady-state water permeability of 458 L m⁻² h⁻¹·bar⁻¹. The SiC membrane could be regenerated through ultrasonication and its steady-state water permeability was almost unchanged for 3 cycles, proving its mechanical robustness. This work may appeal to the practical low-cost production of high-performance SiC membranes.     

偶联剂与固化剂对煤矸石改性酚醛树脂制热固性塑料的影响

以廉价的煤矸石为主要原料,加入硅烷类偶联剂KH550、固化剂乌洛托品等改性物质对酚醛树脂进行改性处理,采用热压成形法制备了热固性酚醛模塑板. 对其部分机械性能和物理性能作了检测,发现固化剂的较佳用量为6%,偶联剂较佳用量为1.5%~2.0%,煤矸石中的有机质有利于改善材料性能,灰分较高的煤矸石对材料性能的改善较差. 所制板材除拉伸强度略低于国家标准外,其余所测指标都达到国家标准,说明煤矸石改性酚醛树脂的思路可行. 关键词：煤矸石;酚醛树脂;热固性塑料;改性     

煤矸石粉填充硫化天然橡胶性能的研究

对废弃煤矸石进行超细粉碎、焙烧,用环氧化天然橡胶(ENR)进行表面处理,然后与硫化天然橡胶(NR)充分混炼,对混炼胶表观交联密度、补强性能、应用性能、动态力学性能等进行了测定。试验结果表明,超细煤矸石粉对NR具有较好的补强性能和分散性。经过ENR改性处理后的煤矸石粉其性能更好,完全可以作为补强填料取代或部分取代炭黑。     

Basic principle,progress, and prospects of coal gangue ceramic proppants

Ceramic proppants are preferred in hydraulic fracturing because of their high strength, good sphericity, and excellent acid corrosion resistance. Bauxite is the main raw material of ceramic proppants, but with the increasing depletion of bauxite resources, substitutes for bauxite need to be sought. Coal gangue is a solid waste that is rich in SiO₂ and Al₂O₃, making it a potential substitute for the preparation of ceramic proppants. The use of coal gangue to prepare ceramic proppants can reduce the cost of ceramic proppants and benefit environmental protection. Studies on using coal gangue to prepare ceramic proppants have been conducted and achieved progress, but further improvement can still be obtained. Here, the basic principle, progress, and prospects of coal gangue ceramic proppants are reviewed. First, coal gangue ceramic proppants are divided into two categories, namely, proppants prepared using coal gangue as an auxiliary material and proppants prepared using coal gangue as the main material. Second, the progress of research of coal gangue ceramic proppants is summarized from the perspective of additives, and the influence of different kinds of additives on the sintering temperature and performance of proppants is discussed. Lastly, the future prospects of coal gangue ceramic proppants are presented.     

煤矸石填充改性聚酰亚胺复合材料的研究

以廉价的煤矸石为填料,利用原位聚合法制备了一种煤矸石填充改性聚酰亚胺(PI)复合材料.用傅立叶变换红外光谱仪和偏光显微镜研究了PI/煤矸石复合材料的微观结构,并测试了复合材料的力学性能和热性能.结果表明,加入适量煤矸石能提高PI/煤矸石复合材料的力学性能,当煤矸石的质量分数为10%时,PI/煤矸石复合材料的降解温度比纯PI提高了34.8℃;煤矸石在PI基体中分散较均匀,粒径为几微米到几十微米.     

贵州典型煤矿区煤矸石灰化释汞研究

为弄清贵州煤矸石资源化利用(烧砖、发电)过程中汞的释放特征,对贵州水城、兴义、麦坪等地典型矿区煤矸石进行了灰化实验,测定了煤矸石在不同灰化温度下的烧失量以及汞含量,研究了煤矸石在灰化过程中汞的含量变化。结果表明:所有煤矸石烧失量在300℃～500℃时随温度的增加与温度呈正相关性,500℃以后烧失量的增长趋势平缓;水城、麦坪、兴义等地煤矸石可燃有机成分高达20%～40%,可作为能源适用于发电、烧砖等;煤矸石中的汞很容易灰化释放,400℃时煤矸石中的汞大部分都可以释放出来,500℃时的灰化产物中汞含量基本趋向零,汞挥发率达到95%左右。