为探索阳离子对水热制备脱硫石膏晶须结晶调控的影响,本文以预处理后的脱硫石膏为原料,NaCl、CuCl2、AlCl3为添加剂采用水热法制备脱硫石膏晶须,重点研究Cl-存在条件下阳离子对脱硫石膏晶须结晶的影响及其作用机理.结果表明,Na+、Cu2+、Al3+对脱硫石膏晶须的显微结构、长径比和品质均有一定的影响,其中Cu2+影响最为显著.Cu2+可在晶须的(200)、(400)和(020)晶面发生化学吸附形成CuSO4膜层,使其径向生长受阻;同时,少量Cu2+可取代Ca2+,促进Ca2+的去溶剂化,使晶须长径比增大至200.Na+和Al3+均通过物理吸附作用于脱硫石膏晶须(200)、(400)和(020)晶面而阻碍其径向生长.此外,Al3+与溶液中的OH-通过羟基化反应生成Al(OH)2+和Al(OH)2+,吸附在带负电的(200)、(400)和(020)晶面,降低这些晶面的表面能,从而促进脱硫石膏晶须沿c轴生长.

为实现污泥在建材中的利用,利用X射线荧光光谱(XRF)仪、激光粒度分析仪、X射线衍射(XRD)仪,对污泥的化学成分、粒度组成和物相进行分析.以污泥和建筑垃圾为主要原料制备蒸养砖,研究不同建筑垃圾和污泥掺量对蒸养砖强度的影响.结果表明,蒸养砖配比为建筑垃圾50％～70％、污泥10％～20％、脱硫干灰10～20％、水泥10％时,抗压强度为10.7～27.2 MPa,抗折强度为3.2～4.7 MPa,满足JC/T 239-2014《蒸压粉煤灰砖》要求,固废总用量达到90％.

以处理后的脱硫石膏为原料,在H2SO4-H2O体系中以Cu(NO3)2为晶形控制剂采用水热法制备脱硫石膏晶须,探讨了Cu(NO3)2对脱硫石膏晶须生长的影响机理.结果表明:Cu(NO3)2对脱硫石膏有明显促溶作用,其中Cu2+可减小溶液中各离子的活度系数,使溶液中的Ca2+浓度增大.NO3-通过静电作用在Ca2+周围聚集并对SO2-4产生屏蔽作用,导致脱硫石膏继续溶解并使Ca2+和SO2-4的浓度处于相对稳定状态,有利于半水脱硫石膏晶体的形核与生长.此外,Cu2+还可在晶须的生长过程中选择性吸附在晶须表面,生成CuSO4,促进了脱硫石膏的结晶生长,最终在Cu(NO3)2用量为2.0％(质量分数)时制备的脱硫石膏晶须长径比约为73.

通过X射线荧光(XRF)、X射线衍射(XRD)测试技术,分析煤矸石、页岩、污泥的化学成分和矿物组成.以煤矸石、页岩和污泥为原料制备烧结砖,研究不同配比和烧结温度对烧结砖强度和物相组成的影响.结果表明,原料配比为10％ 污泥、40％ 煤矸石、50％ 页岩,模压成型砖坯,经1050℃焙烧6 h,可制备出强度达到MU15等级的烧结砖.

Desulfurization gypsum whiskers were prepared by hydrothermal method using purified flue gas desulfurization (FGD) gypsum as raw materials , CuCl2, CuSO4 or Cu( NO3)(2) as additive. The crystal samples were characterized by FTIR , XPS , XRD , etc. to discuss the mechanism of Cu2+ under different anions and these anions in crystal crystallization. The results show that the solubility characteristics of FGD gypsum and the crystal morphology of whiskers are affected by the anions under the effect of Cu2+. The effect of anions is stronger than that of Cu2+ , and the adsorption state of Cu2+ on whisker surfaces is affected by anions. The NO3- promotes the dissolution of FGD gypsum, the CV takes the second place, and the SO42- hinders the dissolution of FGD gypsum. The whiskers with uniform diameter and large aspect ratio are prepared under the effect of Cl-, the whisker samples with high content of granular products can be prepared under the effect of SO42-, and the whisker samples are coarsened under the effect of NO3-. The degree of chemical adsorption of Cu2+ is different under the effect of different anions, which leads to the right drift and narrowing of the antisymmetric stretching vibration absorption peak of SO42- on the surface of the sample, and the differences of the decrease extent of electron binding energy of oxygen elements on whisker surface and the intensity of Cu-O binding energy. The intensity of Cu-O binding energy is the highest under the effect of NO3-, the second under the effect of SO42-, and the weakest under the effect of Cl-.

为实现固体废弃物的资源化利用,采用XRD、XRF等分析测试技术,研究了建筑垃圾和脱硫干灰的化学成分、矿物组成等相关性质.以建筑垃圾、脱硫干灰、矿渣为主要原料,采用压制成型的方法制备蒸养砖,强度达到MU20等级,建筑垃圾用量达到85％,固废总用量达到90％.

The controllable transformation of flue gas desulfurization (FGD) gypsum to calcium sulfate hemihydrate (HH) whiskers under facile, readily monitored, and cost-effective hydrothermal conditions could play a vital role in the preparation of high quality HH whiskers and improve our understanding of the transformation process. This work assessed the conversion of FGD gypsum to HH whiskers in 5 x10(-4) mol/L H2SO4 and 1.5 wt% CuCl2 at 120 degrees C while determining the effects of temperature as well as H2SO4 and CuCl2 concentrations on transformation kinetics. The preparation of HH whiskers was found to involve a solution-mediated transformation from the dihydrate (DH) to the alpha-HH. This transition was determined to proceed via a dissolution crystallization mechanism, the rate of which was controlled by nucleation and growth of the HH whiskers. An autocatalytic kinetic model was established based on variations in the HH whiskers mole fraction over time, and this model accurately fit the experimental data with R-2 = 0.990. Increasing the temperature or H2SO4 concentration accelerated the transformation by modifying the super-saturation and water activity in the reaction solution, while increasing the CuCl2 concentration had the opposite effect. The hydrothermal conditions had an important effect on the transformation from FGD gypsum to HH whiskers. (C) 2020 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

通过添加剂调控制备形貌各异、结晶良好的半水石膏晶体备受关注.简述了有机添加剂、无机添加剂及复合添加剂调控半水石膏晶体生长成纤维状石膏晶须或短柱状高强 α 石膏的研究现状;总结并评述了有机、无机两类添加剂对半水石膏晶体成核和生长过程的调控机制;分析了该领域亟待深入研究的问题,为半水石膏晶体及同类晶体材料的结晶生长控制提供了参考.

近些年,随着石墨烯及其衍生物的问世,利用氧化石墨烯(GO)改性增强水泥基材料已经成为了现代胶凝材料领域一个新的研究方向.针对现有的研究成果,综述了近年来GO在水泥基材料中的研究现状,主要包括GO制备与分散、GO改性水泥基材料性能及作用机理等.此外,还针对目前研究存在的问题进行了总结归纳,并对未来的研究方向进行了展望.

为实现建筑垃圾的资源化利用,采用SEM、XRF、XRD等分析测试技术,研究了建筑垃圾微粉的颗粒形貌、化学成分、矿物组成等相关性质.选用Ca(OH)2、Na2SO4、CaCl2为激发剂,在相同条件下激发建筑垃圾的活性,以建筑垃圾为主要原料,采用压制成型的方法制备蒸压砖,以蒸养砖的强度来评价激发效果.结果 表明:Ca(OH)2激发效果较好,建筑垃圾总用量达到90％,制备的蒸压砖强度达到MU15等级.

Hemihydrate calcium sulfate whiskers (HH-CSWs) were hydrothermally synthesized in a sulfuric acid solution at 120 degrees C for different holding times (20, 40, and 60 min). The phase structures and morphologies were characterized by XRD and SEM, respectively. The XRD pattern of the sample under 60 min was refined via the Rietveld fitting method. The structure models of the HH-CSW sample under a 60-min holding time was established based on Rietveld fitting results. No difference in the positions of diffraction peaks was determined. The as-prepared holding time increased the intensity and aspect ratio of the diffraction peaks of both samples. In the prepared HH-CSW structure, Ca-O polyhedron is a 12-sided polyhedron similar to that in the gypsum structure; the Ca atom is located in two positions in the oneunit cell; the H2O channel along the c-axis similar is O-shaped and bigger than that in hexagonal and monoclinic CaSO4 center dot 0.5H(2)O structures. Therefore, although the prepared HH-CSW crystals' structure are similar to that of the reported hexagonal and monoclinic CaSO4 center dot 0.5H(2)O structures, they are not the same. The formation mechanism of HH-CSW from flue gas desulfurization (FGD) gypsum is discussed based on the analysis of gypsum structure. (C) 2021 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

研究了等温淬火时间对D2冷作模具钢微观组织与力学性能的影响.结果 表明:随等温淬火时间延长,D2钢硬度先升高后降低,冲击韧性逐渐升高;应用Image pro-Plus6.0定量计算的下贝氏体含量逐渐增多,X-射线衍射仪(XRD)衍射图谱显示基体中含有残留奥氏体.其中,270℃等温淬火6h时D2钢硬度与冲击韧性配合最佳,分别达到了61.1 HRC与56 J/cm2,此时试样基体中下贝氏体含量为28.28％;M/B下复相组织中残留奥氏体的碳含量较高,为1.345％,其室温稳定性较强,这更有利于冷作模具在服役过程中组织和精密尺寸的稳定.

以钛酸丁酯、无水乙醇、硝酸银等为原料,通过溶胶-凝胶法制备了不同Ag掺杂含量的TiO2纳米晶粉体,用X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)检测分析了粉体的晶型转化、微观形貌和晶粒尺寸,用光致发光光谱(PL)表征材料的光电性能.结果表明,Ag掺杂后的TiO2纳米晶粉体的锐钛矿相比未掺杂Ag样品的含量有所增多,当Ag掺杂量为1％和3％时,锐钛矿的相对含量约为65％;随着Ag掺杂量的增加,锐钛矿晶粒尺寸逐渐减小;由TEM图像可知,Ag颗粒较为均匀地弥散在TiO2纳米晶粉体中;由PL荧光检测结果可知,Ag掺杂TiO2纳米晶粉体的荧光强度比未掺杂的TiO2纳米晶粉体的低.试验结果表明,Ag颗粒较为均匀地弥散在TiO2纳米晶粉体中,有利于在锐钛矿界(表)面形成Ti-O-Ag的键合,有效阻止锐钛矿向金红石的转变,同时抑制锐钛矿TiO2纳米晶粒的增长,Ag颗粒与TiO2纳米晶粉体接触形成肖特基势垒,加速光生电子由TiO2向Ag颗粒传输,减小光生电子与空穴的复合几率,从而提高TiO2纳米晶粉体的光电性能.

以电厂排放的固体废弃物脱硫石膏、粉煤灰为主要原料,压制成型制备砖材,研究了激发剂对其物理力学性能的影响.研究结果表明:随着激发剂掺量的增加,脱硫石膏-粉煤灰砖的强度先升高后降低.粉煤灰掺量为40％,激发剂掺量为1％,脱硫石膏-粉煤灰砖在龄期14 d时,其抗压强度为6.99 MPa,同时其软化系数为0.75.

Porous, phosphate-silicate glass with high-conductivity and nano-size pores was synthesized through a xero-gel route, using non-ionic surfactant polyethylene glycol monocetyl ether (Brij 56) to control pore size. The influences of Brij 56 concentration on pore size and conductivity under different humidity were studied by measuring conductivity and calculating the volume ratio of adsorbed-water to pore volume. Samples prepared with 0.1 wt% Brij 56 had 5.2 nm pore size, 0.91 volume ratio, and narrower pore size distribution than other samples. The nano-size pores were filled with water, which in pores of 5.2 nm is mostly chemically bonded with the hydroxyl groups on the pore surfaces, resulting in higher conductivity than other samples in high relative humidity (over 55%).

Utilizing the purified flue gas desulfurization (FGD) gypsum as raw material and AlCl3 as crystal modifier to prepare calcium sulfate whiskers (CSWs) by hydrothermal method, the effects of the AlCl3 concentration and the pH of reaction slurry on the crystal morphology of CSW were discussed. The results show that the AlCl3 concentration and the pH of reaction slurry had a significant effect on the crystal morphology of CSWs. CSWs grown in the AlCl3-H2O slurry had diameters ranging from 2 to 6 um and aspect ratio above 80 μm, and their phase structure was calcium sulfate hemihydrate (HH).

以Bi2O3、ZnO和Nb2O5为原料,采用传统固相反应法制备(Bi1.5Zn0.5)(Zn0.5Nb1.5)O7 (BZN)陶瓷.通过CuO包覆层修饰BZN粉体表面,引入CuO助烧剂代替直接混合BZN和CuO粉体.以CuSO4溶液为先驱体制备CuO包覆层,采用液相包覆法引入助烧剂可减少CuO的添加量,从而降低CuO对BZN陶瓷介电性能的不良影响.结果表明,当CuSO4溶液浓度为0.5 mol/L时,可以促进陶瓷的烧结和致密化过程,经900℃烧结3h所得BZN陶瓷介电性能最佳,介电常数(εr)为141,品质因数值(Qf)为426 GHz,谐振频率温度系数(τf)为-357×10-6/℃(4 GHz),皆优于固相混合法所得介电性能(介电常数为134,品质因数为287 GHz,谐振频率温度系数为-374×10-6/℃(4 GHz)).

TiO2 nanocrystalline powders were prepared by sol-gel method with different process parameters. The phase, morphology and the luminescent property of TiO2 nanocrystalline powders were characterized by XRD, SEM and PL, respectively. The results indicated that the synthesized TiO2 nanocrystalline powders were transformed from anatase into rutile with the increasing of heat treatment temperature, which begin at the temperature of 500 oC and was almost completed at the temperature of 700 oC. And with the increasing of pH value the rutile proportion become larger, the nanograins become fine and powders agglomeration was decreased. The good performance TiO2 nanocrystalline powders were obtained when prepared temperature was 500°Cand pH value was 4. PL results show broad and strong luminescence band appeared near 470nm when TiO2 nanocrystalline powders were excited at 325nm at room temperature.

Microstructure of D2 steel after different treatments was analyzed by means of optical microscope (OM),scanning electron microscopy(SEM) and X-ray diffraction(XRD),and the hardness and impact toughness were tested.The influence of solid solution and high temperature tempering spheroidizing pretreatment on the microstructure and property of the D2 steel was studied.The results show that the segregation degree of carbides of the steel decreases obviously after solid solution and high temperature tempering treatment,and the carbon and alloy elements precipitate from the supersaturated martensite matrix during high temperature tempering,and the morphology and distribution of the carbides in matrix are improved by uniform aggregation and growth of alloy carbide particles.The optimum pretreatment process of the steel is tempering at 780 ℃ for 6 h,and the impact toughness increases by 23.8％ after the optimum pretreatment quenching and tempering.

To achive effective utilization of the fly ash residue after extracting aluminium oxide,the basic characteristics of the residue and the preparation of lightweight insulation board were studied. The chemical composition,mineral composition,morphology, size distribution are investigated by means of XRF,XRD,SEM and Laser particle size analyzer. The results show that the residue is mainly consisted of C2S,CaCO3and Ca(OH)2with large specific surface area and porous structure. Based on characteristics of the residue,the fly ash residue after extracting aluminium oxide is used as the main raw materials to prepare the lightweight insulation board. And the optimal ratio of components was follows:35% of fly ash residue,20% of FGD gypsum,15% of thermal insulation mortar,and 30% of water.