低品位煤矸石合成建筑用外墙保温材料的研究

利用低热值高硅低品位煤矸石作为主要原料,同时以石灰石中的碳酸钙作为造孔剂,通过控制烧结过程,最终合成泡沫陶瓷保温材料,并利用XRD、SEM、导热系数仪等对样品进行表征.实验结果表明,随着石灰石含量增加,样品的气孔率增加、体积密度减小、导热系数和抗压强度也随着减小.当石灰石与煤矸石的比例分别为0.5∶1、1∶1时,样品的体积密度分别为1.26 g/cm3、1.06 g/cm3,导热系数分别为0.23 W/(m·K)、0.15 W/(m·K),抗压强度分别为17.99 MPa、6.39 MPa,符合高效能复合外墙外保温材料标准.     

高效隔热保温陶瓷材料的研制

以建筑抛光砖原料为基础料,添加少量的矿化剂和氧化镁,经干压成型后于1220℃-1300℃烧成下制备了具有防水、保温功能的闭孔高温发泡陶瓷.运用XRD、显微镜测试手段对发泡陶瓷的孔径分布、显微结构、物相组成进行了表征,探讨了原料配方、烧成制度对制品的主要性能,如:导热系数、吸水率、密度和强度的影响.结果表明,发泡陶瓷的气孔率高达66.72%(闭孔气孔率为66.39%,开孔气孔率为0.33%);体积密度为0.7987g/cm3,吸水率为0.41%;抗压强度为10.89MPa;导热系数为0.198W/(m·K);主晶相为石英和莫来石;且孔径和气孔率随着烧成温度升高而增大,气孔率越高,发泡陶瓷的抗压强度和导热系数越小.     

工业废渣制备泡沫陶瓷材料及性能研究

以SiC作为发泡剂,采用原位发泡法制备泡沫陶瓷。通过设置正交试验探究原料配比对样品孔隙率、抗压强度等性能的影响,采用X射线衍射、扫描电子显微镜研究样品物相组成及其分布,以及样品的形貌。结果表明,泡沫陶瓷的物相主要为钙钠长石,通过扫描电镜观察到钙钠长石为柱状。固定发泡剂SiC外加量4 wt%,聚乙烯醇外加量8%时,当粉煤灰∶山皮土∶废瓷粉=4:5:4时,样品发泡效果最佳,且样品体密度为0.62 g/cm3、气孔率达63.92%、抗压强度可达5.62 MPa,导热系数为0.086 W/m.K。     

矾土基合成莫来石质多孔陶瓷的研制

采用发泡法与添加造孔剂相结合,以高铝矾土和高岭土为骨料,长石作熔剂,并添加适量的煤、MgSO4和CaSO4作发泡剂,煤为造孔剂,PVA为粘结剂,干压成型后于1500℃左右烧成制备了莫来石质多孔陶瓷。制得的多孔陶瓷莫来石生成量高达90%以上,其气孔分布均匀,孔径分布范围为100～300μm;气孔率高达52.3%（闭孔气孔率为38.7%,开孔气孔率为13.6%）;体积密度为0.9731g/cm3;抗压强度为25.1317MPa;导热系数为0.143W/（m.K）的多孔陶瓷。     

泡沫粉煤灰保温砖的制备与性能研究

以粉煤灰为主要原料,以石灰石为发泡剂制备了泡沫粉煤灰保温砖.研究了粉煤灰的用量、石灰石的用量、烧成温度、保温时间对泡沫粉煤灰保温砖的密度、气孔率、导热系数和抗压强度的影响;采用扫描电镜、电子万能试验机和快速热导仪等手段对样品性能进行了表征.实验结果表明,当粉煤灰用量50wt％,石灰石用量15wt％,烧成温度1050℃,保温时间90min时,制备的泡沫粉煤灰保温砖密度为0.55g/cm3,气孔率为58.8％,导热系数为0.13W/m·k,平均抗压强度为4.0MPa;本方法工艺简单,成本低,环保.泡沫粉煤灰保温砖气孔的形成机理是一种气相、液相和固相之间动态平衡的结果.     

粘土基地质聚合物多孔材料的制备及性能研究

本文以粘土和工业水玻璃为主要原料,采用高温发泡法制备了一种具有一定强度的轻质地聚物多孔材料.实验表明:该材料的体积密度在0.32～1.0 g/cm3之间,抗压强度在0.46～2.68 MPa之间;对不同条件下泡沫材料进行显微结构分析,可知其抗压强度、体积密度等性能与气孔率、气孔尺寸大小、均匀程度等有很大关系.     

双氧水发泡法制备泡沫陶瓷外墙保温板

本文以粉煤灰和铜尾矿为主要原料,掺加膨润土和赤泥,以长石为助熔剂,双氧水为发泡剂,聚乙烯醇为稳泡剂,采用浆料发泡烧结法制备泡沫陶瓷外墙保温板.确定了适宜的原料组成为粉煤灰40％％铜尾矿38％％长石10％％膨润土10％％赤泥2％％双氧水的加入量为5％％所制备的泡沫陶瓷的性能为:吸水率0.90％％体积密度1.10g/cm3、显气孔率为0.70％％抗压强度为8MPa、导热系数为0.15 W/m·k.     

料浆pH值对YSZ/SiO2气凝胶复合多孔隔热材料性能的影响

制备了YSZ/SiO2复合轻质多孔隔热材料,借助FE-SEM、万能材料试验机、导热系数仪、压汞分析仪和zeta电位仪等测试手段系统研究了料浆pH值对YSZ/SiO2气凝胶隔热材料的导热系数、抗压强度、密度和气孔率等性能的影响规律。研究结果表明:在pH考察范围为4～12时,隔热材料的导热系数呈“W”型变化,材料的密度和抗压强度随p H的增大呈现先减小,后增大、再减小的变化规律,最优料浆p H值为10,制得样品的导热系数、抗压强度、密度和气孔率分别为0.043 W/(mk),35.6 MPa,1.51 g/cm3和60.9%。     

电解锰废渣-废陶瓷磨细粉制备再生陶瓷砖

以电解锰废渣、废陶瓷磨细粉制备再生陶瓷墙地砖.以抗压强度、吸水率、气孔率、体积密度为主要参考指标,研究再生陶瓷墙地砖的最佳配合比及最佳烧成制度,探讨烧成制度对其性能的影响.结果表明:影响再生陶瓷墙地砖性能的主要因素由大到小依次为烧成温度、保温时间、成型压力.随着烧成温度的提高,样品抗压强度先增大而后降低,吸水率先降低后增大.再生陶瓷墙地砖的最佳配合比为10％电解锰废渣、90％废陶瓷磨细粉.最佳烧成温度为1150℃、保温时间为90 min、成型压力为98 MPa.制得样品的吸水率为0.75％,抗压强度为25.2MPa、体积密度为2.88 g/cm3,符合GB/4100-2006《陶瓷砖》中BIa类标准.     

发泡剂对钼尾矿多孔陶瓷性能的影响

采用高温熔融直接发泡制备钼尾矿多孔陶瓷,通过研究不同发泡剂对钼尾矿多孔陶瓷材料性能的影响,确定最合理的发泡剂,研究了最合适的发泡剂对多孔陶瓷气孔率以及抗折抗压强度的影响。结果表明,SiC在体系中发泡性能最好,随着SiC含量的变化,钼尾矿多孔陶瓷气孔率和抗折强度均发生变化,当SiC含量为0.1wt%时,气孔率为81%,体积密度为0.4g/cm~3。显微结构表明孔结构基本上不连通分布均匀,为闭孔材料。     

Preparation and properties of ferrimagnetic glass–ceramic foams based on pyrite slag

By employing a melt-sintering method, we prepared a new type of ferrimagnetic glass–ceramic foam (FGCF) using ferrimagnetic glass–ceramic and foaming agent SrCO₃. The ferrimagnetic glass–ceramics were fabricated based on pyrite slag by a melt-quenching method. The effects of foaming agent content, sintering temperature and time on microstructure, magnetic properties, microwave absorption performance, compressive strength, and thermal conductivity of the as-obtained FGCF were analyzed. This foaming process at 1100°C for 40 min with 3-wt% SrCO₃ provided an FGCF with a bulk density of .693 g/cm³, a porosity of 63.60%, a specific saturation magnetic moment of 5.2 A m²/kg, a compressive strength of 2.61 MPa, a thermal conductivity of .241 W/(m K), and the calculated reflection loss of −12.1 dB for a layer thickness of 9 mm.     

轻质环氧树脂微孔发泡材料的力学及隔热性能

通过添加不同含量的化学发泡剂,制备了较小密度(0.5 g/cm~3)的环氧树脂基微孔发泡材料,研究了发泡剂含量(0.25%~2%)对环氧复合发泡材料发泡行为的影响,并讨论了材料的力学性能及隔热性能的变化规律。结果表明,随着发泡剂含量的增加,材料的表观密度不断降低,但泡孔尺寸不断增大,泡孔密度则不断降低。力学性能及隔热性能测试表明,随发泡剂含量的增加,材料的压缩屈服强度和压缩弹性模量不断降低,但是材料的隔热性能不断提高。     

泡沫掺量对发泡碱激发矿渣聚合物性能和孔隙特征的影响

以水玻璃激发矿渣为胶凝材料,采用压缩空气发泡方式制备了泡沫矿渣聚合物材料,通过Image-Pro plus(IPP)表征了不同泡沫掺量下泡沫矿渣聚合物的孔隙结构特征,并研究了泡沫掺量对泡沫矿渣矿物聚合物干密度、抗压强度和导热系数的影响.结果表明:当泡沫掺量为4.45%~10.70%(质量分数)时,随泡沫掺量增加,泡沫矿渣聚合物的孔隙率增加、平均孔径及孔圆度值增大,泡沫矿渣聚合物相应的干密度、抗压强度和导热系数均呈负指数关系降低且相关性强;当泡沫掺量为4.45%~12.00%(质量分数)时,所制备碱激发矿渣聚合物泡沫材料的干密度389~1325 kg/m3、抗压强度1.12~17.81 MPa、导热系数0.0813~0.2211 W/(m·K),其综合性能优于通用水泥泡沫混凝土制品.     

Thermal conductivity of high porosity alumina refractory bricks made by a slurry gelation and foaming method

Alumina has high heat resistance and corrosion resistance compared to other ceramics such as silica or mullite. However, for its application to refractory bricks, its high thermal conductivity must be reduced. To reduce this thermal conductivity by increasing the porosity, a GS (gelation of slurry) method that can produce high porosity solid foam was applied here to produce the alumina refractory brick. This method was successfully applied to produce alumina foam with high porosity and thermal conductivity of the foam is evaluated. At room temperature, the thermal conductivity was about 0.12 W/mK when the foam density was 0.1 g/cm³. At elevated temperature above 783 K, thermal conductivity of the foam was strongly affected by heat radiation and increased with increasing temperature, in contrast to the thermal conductivity of alumina itself, which decreased with increasing temperature. The alumina foams developed here achieved sufficient thermal insulating properties for use in refractory bricks.     

Hierarchically porous lanthanum zirconate foams with low thermal conductivity from particle-stabilized foams

Lanthanum zirconate (LZO) ceramic foams with hierarchical pore structure were fabricated by particle-stabilized foaming method for the first time, and the as-prepared ceramics have high porosity of 90.7%-94.9%, low thermal conductivity, and relatively high compressive strength. The LZO powder was synthesized by solid-state method. The porosity of the ceramic foams was tailored by suspensions with different solid loadings (20-40 wt%). The sample with porosity of 94.9% has thermal conductivity of 0.073 W/(m·K) and compressive strength of 1.19 MPa, which exhibits outstanding property of thermal insulation and mechanical performance, indicating that LZO ceramic foam is a promising thermal insulation material in high temperature applications.     

Preparation and microstructure evolution of novel ultra-low thermal conductivity calcium silicate-based ceramic foams

In this study, municipal solid waste incineration fly ash (MSWI FA) was used as a new raw material for the ceramics industry and a novel ultra-low thermal conductivity calcium silicate-based foams (CSFs) was prepared by the direct foaming method. The effects of the addition of foam and borax on the sintering behavior and microstructural evolution of the CSFs were investigated. With the optimal amount of foam, the CSFs had an apparent porosity of 63.43%–67.49%, bulk density of 0.75–0.84 g/cm³, compressive strength of 1.83–3.21 MPa, and room-temperature thermal conductivity of 0.213–0.235 W/(m·K). Notably, the whisker morphology, pore structure, and sintering behavior of the samples can be controlled by changing the amount of borax. The prepared ceramic foams can be applied in the fields of thermal insulation, filtration, and catalyst carriers.     

工艺参数对铁尾矿制备泡沫玻璃性能的影响

以铁尾矿为主要原料、CaCO3和Na2CO3为发泡剂、Na3PO4×12H2O和硼砂(Na2B4O7×10H2O)为稳定剂,制备了性能良好的泡沫玻璃材料,并研究了工艺参数对制品性能的影响. 结果表明,CaCO3为主要发泡剂,Na2CO3含量对制品性能影响不大;Na3PO4×12H2O为主要稳定剂,Na2B4O7×10H2O含量不宜过多;发泡温度升高使制品孔径变大、容重和抗压强度降低;而烧结温度升高使制品的容重和抗压强度均先减小后增大. 制备泡沫玻璃适宜的工艺参数为(%, w)：基础玻璃84, CaCO3 3, Na2CO3 2, Na3PO4×12H2O 8, Na2B4O7×10H2O 3, 发泡温度900~950℃,烧结温度1100℃. 由此制得的泡沫玻璃材料容重约为2.05 g/cm3,抗压强度达62 MPa左右.     

Waste-to-resource preparation of glass-containing foams from geopolymers

Waste glass-based cellular geopolymers with total porosity about ~55?vol%, thermal conductivity of ~0.21?W/mK, and compression strength of ~7.3?MPa were successfully produced by a direct foaming technique using hydrogen peroxide (chemical pore-forming agent) in combination with Triton X-100 (stabilizing agent). Thermal treatment of these porous geopolymers at 700–900?°C resulted in a significant increase in volume (secondary foaming). Interconnected pores with a wide range of sizes, ranging typically from 50 to 3000?µm, formed through this foaming process. Glass and glass-ceramic foams (GFs), possessing high overall porosity (77?< P_t <?88?vol%), low bulk density (0.27?< ρ_b <?0.48?g/cm³), low thermal conductivity (0.11?< λ?<?0.15?W/(m?K)), and remarkable compression strength (1.2?<?σ?<?5.5?MPa), were successfully fabricated through the secondary foaming. The obtained results confirmed that this is a viable method for the waste-to-resource production of glass-based foams.     

A novel way to fabricate fibrous mullite ceramic using sol-gel vacuum impregnation

Inspired by bird's nest structure, fibrous mullite ceramic was fabricated by vacuum impregnation with mullite fibers as raw material and zirconia sol-gel as inorganic binder. The effect of impregnation times on the properties of the fibrous mullite ceramic, such as porosity, microstructure, compressive strength and room-temperature thermal conductivity were investigated. The results showed that low density (0.45–0.66?g/cm³), relative high compressive strength (0.62–3.34?MPa) and low thermal conductivity (0.037–0.125?W/mk) were exhibited for the sample. The toughness of fibrous mullite ceramic was enhanced due to the micro-creaks caused by transformation of zirconia. From the experimental results, it is suggested that it was an optimal method which have the potential use in high-temperature thermal insulation materials to produce fibrous mullite ceramics.     

氧化锆泡沫陶瓷过滤板的制备与性能研究

以氧化锆(ZrO2)粉为主要原料,氧化铝(Al2O3)粉和氧化钇(Y2O3)粉为烧结助剂,采用有机泡沫浸渍工艺制备出高性能氧化锆泡沫陶瓷过滤板。研究了烧成温度和保温时间对样品容重、抗热震性和抗压强度的影响。采用万能试验机、综合热分析仪、X射线衍射仪、扫描电镜等对样品性能进行了表征。实验结果表明,当烧成温度为1580℃,保温时间为120 min时,制备的氧化锆泡沫陶瓷过滤板性能最佳,其容重为0.452 g/cm3,抗热震性为12次,抗压强度为1.56 MPa。