Design, fabrication, microstructure, and properties of highly porous alumina whisker foam ceramic

Colloidal co‐assembly of dual‐phased ceramic/metal particles toward lightweight, hierarchically structured, and mechanically robust alumina foam

“…Although a variety of alumina porous ceramics have been successfully fabricated via colloidal assembly, 3D printing, and foam templating, highly porous products are rarely reported. The high porous alumina products in the reported works exhibited relatively low compressive strengths 24–30 . In the present work, the colloidal co‐assembly allows the fabrication of highly porous alumina ceramics with a porosity level of 86%–92% and a corresponding compressive strength of 1.62–3.64 MPa via the incorporation of 5–15 wt% Al.…”

“…The high porous alumina products in the reported works exhibited relatively low compressive strengths. [24][25][26][27][28][29][30] In the present work, the colloidal co-assembly allows the fabrication of highly porous alumina ceramics with a porosity level of 86%-92% and a Porous ceramics with hierarchical pore structures are usually utilized as adsorbents. In this work, the specific surface areas of calcined samples were evaluated via an N 2 adsorption-desorption test (Figure 7).…”

Porous ceramics with near‐zero shrinkage and low thermal conductivity from hazardous secondary aluminum dross

“…It is found that the aluminabased porous ceramics prepared by this method have the advantages of low sintering shrinkage, outstanding mechanical strength, and thermal insulation, the performance of which is also comparable with those prepared from pure Al 2 O 3 powder. 66,67 From commonly used pure Al 2 O 3 powder, porous alumina ceramics with bulk density of 0.10-0.65 g/cm 3 possess thermal conductivity of 0.10-11.00 W/(m⋅K), 12,68,69 while porous aluminabased ceramics in the present work show relatively low thermal conductivity of 0.65-1.15 W/(m⋅K) at relatively high bulk density of 1.83-2.32 g/cm 3 . Moreover, the process is simple, versatile, and enables high utilization proportion of SAD (up to 100%) in the starting materials.…”

Reaction Sintered Porous Ceramics Using Iron Tailings: Preparation and Properties

“…Key words: iron tailing; porous ceramics; SiC; reactive sintering; foam gel-casting 铁尾矿是铁矿石通过粉碎和分离技术提取可回 收金属等有价值矿物后剩余的固体废弃物 [1][2] 。我国 是全球钢铁产量最高的国家，由于铁尾矿利用率有 限，长期以来积累了大量的尾矿废弃物 [3] 。目前，铁 尾矿的利用主要包括金属资源再回收 [4] 、回填 [5] 、开 垦耕地 [6] 、生产建筑材料等 [7][8] 。在建材领域，将铁尾 矿应用于生产水泥和混凝土已有大量的研究和探索 [9][10] ，但可利用的部分仅限于粗颗粒铁尾矿，大量含 有黏土矿物及难挥发水分的泥状细颗粒铁尾矿尚未 找到有效的利用途径，只能筑坝堆存，由此会造成环 境污染、侵蚀和渗漏等诸多问题 [11][12] 。因此，探索铁 尾矿利用新技术，尤其是对于泥状细颗粒铁尾矿的 利用技术，对于解决铁尾矿资源化利用这一难题具 有重要的意义。 研究表明，在商业和住宅建筑中用于供暖和制 冷系统的能源消耗逐年增加，造成了巨大的经济负 担 [13] 。将保温材料应用于建筑物墙壁、屋顶、地 板等 部位可以有效降低能源损耗 [14][15] 。相比于聚苯乙烯 [16] 、 酚醛泡沫 [17] 等有机保温材料， 无机保温材料具有 防火等级高、环保、耐老化等优异性能 [18] ，在节能建 筑中有着广阔的应用前景。同时，利用相变材料存储 和释放热能对建筑物实施主动控温是一种更为有效 的节能手段 [19][20][21][22] 。如何利用细颗粒铁尾矿制备满足 上述两种用途的新材料，对于开发铁尾矿新的应用 领域是一项挑战。 多孔陶瓷具有低密度、高孔隙率、低热导率、耐 高温、机械性能好等优点，是一种性能优良的保温隔 热材料 [23][24][25] 。其制备方法之一是在原料中引入陶瓷 抛光渣 [26][27] ，利用抛光渣中碳化硅等成分在高温下 氧化产生的气体使陶瓷发泡 [28] ，提高材料的孔隙率， 降低热导率。此外，采用料浆搅拌发泡、凝胶注模成 形等工艺 [29][30] 可制备高孔隙率的多孔陶瓷 [31] ，通过 调节料浆浓度和烧结工艺，控制多孔陶瓷的孔隙率 和孔径尺寸 [32] ，从而达到控制热导率的效果 [33] [35][36][37] 。 5)所示 [38]…”