城市污泥-煤矸石-稻壳制备轻质烧结砖的研究

在研究分析城市污泥和煤矸石理化特性的基础上,以城市污泥和煤矸石为原料、稻壳作为造孔剂制备轻质烧结砖.结果表明,当城市污泥用量在50％时,随着污泥的增加,烧结砖的表观密度和抗压强度逐渐减小,而气孔率和吸水率逐渐增大;当污泥用量超过50％范围后,随着污泥的增加,烧结砖的表观密度和抗压强度反而有所增大,吸水率和气孔率相应明显减小.当煤矸石∶污泥=60∶40时,外掺6％和10％稻壳时,相应轻质烧结砖的抗压强度为10.27 MPa和4.44 MPa,分别达到承重墙体材料和非承重墙体材料抗压强度的国家标准要求.污泥中重金属等有害物质经过高温焙烧,形成稳定的固溶体,不会造成对人体及环境危害.     

煤矸石提铝提硅废液对烧结砖性能的影响研究

以煤矸石、粉煤灰和煤矸石提铝提硅废液为主要原料制备烧结砖,研究废液掺量对烧结砖抗压性能的影响。结果表明,不掺加废液时,烧结砖的最佳配方为:煤矸石80%,粉煤灰20%,水固比为15%,烧结砖的抗压强度为29.78 MPa;废液替代水的量为50%时,烧结砖的抗压强度为24.97 MPa,满足MU20等级的要求。     

煤矸石中杂质含量对堇青石多孔陶瓷烧结与性能的影响

通过不同酸浸处理时间控制煤矸石原料中的杂质含量,研究煤矸石原料中杂质含量对有机海绵浸渍法制备的多孔堇青石陶瓷烧结过程和性能的影响.通过X射线衍射分析和扫描电镜研究了烧结过程中的物相结构的演变及微观结构变化等特性.并考察了酸浸处理时间和烧结温度对多孔陶瓷样品的显气孔率和抗压强度影响.结果表明,使用酸浸处理后的煤矸石为原料制备的多孔堇青石陶瓷气孔率和抗压强度均显著增加,1200℃下,使用未经酸浸的煤矸石制备的多孔堇青石陶瓷,气孔率为73.69％,抗压强度为2.23 MPa;而酸浸处理8h后,陶瓷样品的气孔率保持在78.78％,抗压强度提高至3.33 MPa.讨论了酸浸处理对煤矸石原料中起烧结助剂作用的杂质含量的调控以及杂质含量对物相形成和陶瓷性能的影响规律.煤矸石原料中这些杂质的存在也降低了堇青石陶瓷的烧结温度.     

空心微珠轻质陶粒的制备与性能EI北大核心CSCD

以煤矸石空心微珠和玻璃空心微珠坯体为主要原料,采用滚动成球法制备陶粒生坯,经烘干、烧结,得到轻质陶粒,研究了烧结温度、保温时间以及玻璃粉添加量对空心微珠轻质陶粒性能的影响。结果表明:随着烧结温度的升高,陶粒的表观密度和吸水率逐渐增大,颗粒抗压强度先增大后逐渐减小;烧结温度为700℃,单颗粒抗压强度为200.5 N,达到最大值。随着保温时间的延长,颗粒抗压强度先增大后减小。加入玻璃粉可以明显提高陶粒的单颗粒抗压强度,并且随着玻璃粉加入量的增大,颗粒抗压强度显著增大,700℃烧结的样品中玻璃粉加入量为25%(质量分数)时,单颗粒抗压强度增大到327.5 N,提高了63.3%。     

空心微珠轻质陶粒的制备与性能

以煤矸石空心微珠和玻璃空心微珠坯体为主要原料,采用滚动成球法制备陶粒生坯,经烘干、烧结,得到轻质陶粒,研究了烧结温度、保温时间以及玻璃粉添加量对空心微珠轻质陶粒性能的影响。结果表明:随着烧结温度的升高,陶粒的表观密度和吸水率逐渐增大,颗粒抗压强度先增大后逐渐减小;烧结温度为700℃,单颗粒抗压强度为200.5 N,达到最大值。随着保温时间的延长,颗粒抗压强度先增大后减小。加入玻璃粉可以明显提高陶粒的单颗粒抗压强度,并且随着玻璃粉加入量的增大,颗粒抗压强度显著增大,700℃烧结的样品中玻璃粉加入量为25%(质量分数)时,单颗粒抗压强度增大到327.5 N,提高了63.3%。     

成型方式对石英砂烧结砖性能的影响研究

利用低品位石英砂制备高性能石英砂烧结砖,通过对原料和砖体物相分析、砖体的显微结构分析以及砖体的物理性能分析,研究了成型方式对砖体性能的影响。结果表明:等静压成型的压力比手压成型的大得多,使得坯体内部气孔数量少且孔径小,有利烧结。等静压成型所制备的砖体抗压强度(34.8MPa)比可塑(手压)成型的砖体抗压强度(19.5MPa)高得多,但与烧结砖的国家标准相比,两种成型方式的烧结砖各种性能都达到标准。     

煤矸石-粉煤灰烧结砖的研制

利用煤矸石和粉煤灰烧结砖不但可减少固体废弃物的排放,还可创造可观的经济效益.利用阜新本地煤矸石和粉煤灰,经原料制备、原材料的处理、砖坯成型和烧结等工艺,可生产出满足国家质量标准的烧结砖.经制备工艺正交试验,制品抗压强度主要受材料配比和烧结温度的影响,其次是升温速率和保温时间.由于助熔剂的加入,煤矸石-粉煤灰砖的焙烧温度可以由1200℃降低到1100～1150℃.由试验分析的结果,合理的材料配比为:灰矸比3∶7,外加2％玻璃粉;合理的砖坯成型水分为12％,砖坯成型压力为30 MPa;合理的烧成制度为:升温速率80min/h,烧成温度1150℃,保温时间100 min.研制的烧结砖呈粉红色至砖红色,与普通粘土砖基本相同,外观规整,无裂纹其它大的缺陷且无石灰爆裂现象.产品从制坯到烧成的过程中各方向的变形均满足质量要求.本文研究为普通黏土烧结砖厂技改成煤矸石-粉煤灰砖厂提供了有力的技术保障.     

新型建筑烧结砖烧成性能的研究

烧结砖是传统的主要建筑材料之一,新型烧结砖是利用淤泥等固体废弃物资源化利用而制成的烧结砖,与一般的红砖生产过程相比,环保性能良好,能源利用率高。本文通过对原料的组分分析、差热曲线分析、热膨胀分析、烧失分析以及烧结性能的分析研究建筑烧结砖的烧结性能,能对企业的生产带来一定的意义。     

等静压成型压力对石英砂烧结砖性能的影响研究

利用低品位石英砂制备高性能石英砂烧结砖,通过对原料和砖体物相分析、砖体的显微结构分析以及砖体的物理性能分析,研究等静压成型压力对砖体性能的影响.结果表明:随着成型压力的增加,砖体的烧结温度逐步降低至最低点然后升高,其中65MPa成型的砖体比100MPa成型的砖体的烧结温度要高15℃.砖体的抗压强度随着成型压力的增大,先升高后降低,其中在100MPa等静压成型所制备的砖体抗压强度达到35.1MPa,与烧结砖的国家标准相比,性能达烧结普通砖的国家最高标准MU30级.     

利用煤矸石制备泡沫陶瓷的研究

以煤矸石为研究对象,利用XRD和XRF技术,研究了煤矸石的矿物组成和化学成分.以煤矸石和低品位铝矾土为主要原料,长石作为助熔剂,振实成型后在1 200℃下焙烧成泡沫陶瓷.结果 表明,当原料中煤矸石的含量为61wt％时,所制备泡沫陶瓷的基本性能为:导热系数0.059 W/(m·K)、体积密度118.6 kg/m3、体积吸水率1.3％、抗压强度1.3 MPa、抗折强度1.4 MPa.利用煤矸石制备泡沫陶瓷,为煤矸石综合利用提供了一条可行的途径.     

粒径对煤矸石填充聚合物复合材料性能的影响

采用不同粒径的煤矸石粉填充高密度聚乙烯制备复合材料,研究了球磨时间对煤矸石粉体粒径的影响和粒径对煤矸石粉填充聚合物复合材料的力学性能的影响。结果表明:粒径对复合材料的性能影响明显,SEM照片显示超细煤矸石粉与HDPE相容性好;当粒径由100目提高到6000目,填充量为30%时,复合材料的弯曲模量提高了30.77%,弯曲强度提高了37.9%,拉伸强度也提高了20.12%,达到增强、增韧的目的。     

纳米α-Al_2O_3的湿化学法制备

以硝酸铝和碳酸氢铵为主要原料,采用湿化学法,在1 135℃煅烧2 h,制备了平均晶粒尺寸为31.6 nm的α-Al2O3纳米粉末。研究了表面活性剂及水与乙醇的体积比的溶剂以及前驱体的煅烧温度和时间对合成粉末的相组成及晶粒大小的影响。结果表明,制备前驱体的最佳滴定速度为将Al(NO3)3溶液一次性全部加入NH4HCO3溶液中,水和无水乙醇的最佳体积比为1∶1,分散效果最好的分散剂是PEG6000;前驱体的最佳煅烧温度为1 135℃,时间为2 h。     

Characteristics of brick used as aggregate in historic brick-lime mortars and plasters

Mortars and plasters composed of a mixture of brick powder and lime have been used since ancient times due to their hydraulic properties. In this study, raw material compositions, basic physical, mineralogical, microstructural and hydraulic properties of some historic Ottoman Bath brick-lime mortars and plasters were determined by XRD, SEM-EDS, AFM, TGA and chemical analyses. The mineralogical and chemical compositions, microstructures, morphologies and pozzolanicities of the brick powders and fragments used as aggregates in the mortars and plasters were examined to find out the relationship between hydraulic properties of the mortars and the bricks. The characteristics of bricks used in the bath domes were also determined to investigate whether the brick aggregates used in mortar and plasters were prepared from these bricks. The results indicated that the mortars and plasters were hydraulic owing to the presence of crushed brick powders that have good pozzolanicity. The brick powders had high pozzolanicity because they contained high amounts of calcium-poor clay minerals in their raw materials that were fired at low temperatures. On the other hand, bricks used in the domes had poor pozzolanicity with different mineralogical and chemical compositions from bricks used in mortars and plasters. Based on the results of the analysis, it was thought that the bricks manufactured with high amounts of clays were consciously chosen in the preparation of hydraulic mortars and plasters.     

Use of mineral coal ashes in insulating refractory brick

Coal ash from Candiota thermoelectric power plant in southern Brazil is a waste generated in great amount. Current estimates indicate that coal ash production is likely to reach 2.000.000 tons per year. Of this total, only 10% are commercialized, so the price of this material is very low. In this work, it was investigated the use of coal ashes in a composition of refractory insulating brick. In coal combustion process, fly ashes and bottom ashes are generated. Bottom ashes are formed by partially fused ashes that precipitate to the bottom of the boiler, due to their coarser particle size. Therefore, it was analyzed fly ash addition in a refractory body and the addition of bottom ashes, partially replacing chamote (calcinated clay). The results showed that the effect of the ash is small in the fired materials. In terms of technological characterization, the bricks formulates with coal ash were considered suitable to commercial brick standards. Density and thermal conductivity of the refractory bricks with coal ashes had revealed to be similar the commercial products. Then, the use of ash is economical attractive and technical feasible. Translated from Novye Ogneupory, No. 6, pp. 60–63, June 2008.     

Effect of Size Distribution of the Starting Powder on the Pore Size and its Distribution of Tape Cast Alumina Microporous Membranes

Thin disc type pure alumina membranes have been prepared by tape casting technique. Pore size distribution and pore volume have been determined by mercury porosimetry. Initial particle size of the alumina powder and the size distribution are found to have a strong influence on the ultimate median pore size and pore size distribution of the fired membranes. The spread of the particle size distribution of the powders is expressed by ‘quartile ratio’ which represents the size ratio corresponding to the cummulative finer percentages of 75 and 25 in the particle size distribution curve. With higher quartile ratio ( wider particle size distribution ) not only the median pore size increases but also the distribution tends to be bimodal. This is explained on the basis of certain basic sintering behaviors of the fine powders in general. ©     

煤矸石对泡沫混凝土孔结构的影响

本文将粉磨之后的煤矸石替代部分水泥掺入到混凝土中,通过物理发泡工艺制备煤矸石泡沫混凝土。采用FiJi-imageJ图像分析技术等对泡沫混凝土的孔径分布、平均孔径、气孔直径等进行表征,分析了煤矸石改善泡沫混凝土成孔的原因以及煤矸石粉磨粒径对泡沫混凝土抗压强度的影响。结果表明:当掺入粒径为45 μm的煤矸石粉时,泡沫混凝土的强度随着掺量的增加逐步下降,而掺入粒径为15 μm的煤矸石粉时,强度则随掺量的增加呈先上升后下降的趋势;在调节孔结构方面,粒径为45 μm的煤矸石粉优于粒径为15 μm的煤矸石粉,并在50%(质量分数)掺量下达到最优效果。     

超塑性Y-TZP增韧陶瓷超细粉末的研究

用化学共沉淀法制备了3mol％Y_2O_3-ZrO_2超细粉末。利用热分析,x射线,透射电镜,颗粒粒度分析仪分析了粉料的相组成;颗粒形貌、大小;粉料的团聚状态;化学组成的均一性以及其烧结性能,并结合烧结试样的显微结构和力学性能对粉末的性能做出了评价。实验表明,所制备的粉料组成较为均匀;粒度分布窄;团聚体尺寸小,烧结活性高;颗粒粒度约为200(?)。粉料的相组成主要为四方相和约26％的单斜相。3Y-TZP陶瓷材料三点弯曲强度达1479.14MPa,断裂韧性为13.2MPa·m~(1/2),超塑性压缩变形达190％。     

煤矸石颗粒群分布与其水泥性能的关系

把对经过热激活处理的煤矸石试样按不同粉磨工艺处理成具有不同颗粒群分布的试样,用激光粒度仪对煤矸石粉体试样进行了颗粒群分布测试,并以Rosin-Rammler线性回归进行拟合。在均匀性系数n,特征粒径De与勃氏比表面积S三个颗粒群特征参量中,分别确定其一,变化其它参量进行煤矸石水泥胶砂宏观性能测试,以期考察煤矸石粉体颗粒群分布与其水泥性能的关系。     

粒径对煤矸石填充聚合物复合材料性能的影响

采用不同粒径的煤矸石粉填充高密度聚乙烯制备复合材料,研究了球磨时间对煤矸石粉体粒径的影响和粒径对煤矸石粉填充聚合物复合材料的力学性能的影响。结果表明：粒径对复合材料的性能影响明显,SEM照片显示超细煤矸石粉与HDPE相容性好;当粒径由100目提高到6000目,填充量为30％时,复合材料的弯曲模量提高了30．77％,弯曲强度提高了37．9％,拉伸强度也提高了20．12％,达到增强增韧的目的。     

坯粉性能对釉面砖热稳定性的影响

主要论述了坯粉含水率、粒度、流动性、容重对釉面砖热稳定性的影响，初步确定了有利于提高釉面砖热稳定性的坯粉的各种工艺参数。确定，使用含水率为6．5％～8．5％，粒度为0．25～0．125mm，且容重大、流动性好的坯粉，对提高热稳定性有利。