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1.
Waste ceramic sands were effectively used to prepare the high-intensity and low-density ceramic proppants, realising the recycling of the waste ceramic sands. The technology involved the pelletising in an intensive mixer, in which the waste ceramic sands and other starting materials were added, and followed by heat-treatment under different sintering conditions. The sintering temperature, holding time and heating rate were optimised by investigating the crystalline phase, microstructure, density and breakage ratio of the obtained proppants. The results showed that the proppants sintered at 1260°C for 2?h with a heating rate of 5°C?min–1 under air atmosphere exhibited high crush resistance and low density, with the breakage ratio of 8.5% under 52?MPa closure pressure and bulk density of 1.65?g?cm–3. The proppants prepared by bauxite, waste ceramic sands and sintering aids are promising candidates as high-intensity and low-density fracturing proppants in future applications. 相似文献
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以二级铝矾土生料、黏土为原料,以锰矿粉和碳酸钙为烧结剂,制备了高强度陶粒支撑剂材料,并讨论了锰矿粉加入量(w)0、1.0%、3.0%、5.0%、7.0%和碳酸钙加入量(w)0.5%、1.0%、1.5%、2.0%以及热处理温度为1 280、1 320、1 360、1 400℃时对支撑剂材料性能的影响。结果表明:随锰矿粉加入量的增加,试样烧结致密度提高,强度增大,当锰矿粉加入量≥5.0%(w)时,试样的强度基本不变;在加入5.0%(w)锰矿粉基础上,添加碳酸钙,试样烧后强度随碳酸钙加入量的提高而提高;碳酸钙加入量为2.0%(w)时,试样的强度达到275 MPa;同时添加5.0%(w)锰矿粉和2.0%(w)碳酸钙的试样的较佳热处理温度为1 360℃。 相似文献
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Mei Qin Yuming Tian Huilan Hao Guomin Li Yi Zhou Pinbo Bai 《International Journal of Applied Ceramic Technology》2020,17(3):1026-1032
Corundum-mullite ceramic proppants have been successfully synthesized using raw materials of natural bauxite and solid waste coal gangue, CaCO3, as additive. The influences of calcium carbonate additive on phase composition, microstructure, and mechanical performances were systematically investigated. The results indicate that the addition of CaCO3 promotes the formation of liquid phase at lower temperature during sintering process, which is beneficial to the densification of the samples and the reduction of sintering temperature. Moreover, the mullite grains become finer and finer with the content of CaCO3 additive increasing, which improves the toughness and strength of the samples via a grain refinement strengthening mechanism. The ceramic proppants exhibit optimal performances with additive of 5 wt.% at 1350°C, and the breakage ratio under 52 MPa closed pressure is the lowest. Additionally, the sintering temperature is dropped by 150°C compared with the samples without adding calcium carbonate. 相似文献
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C. Birkinshaw M. Buggy A. O'Neill 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1996,66(1):19-24
A processing route for fabrication of products from hard metal and ceramic powders is described in which a reactive monomer such as ethylcyanoacrylate is used as carrier and binder with the opportunity of recovery through thermal depolymerization. A feasibility study has examined some of the main technical points including monomer–powder reactivity and rheology, debinding rates and compact green density. The stability of ethylcyanoacrylate with various powder volume fractions of silicon nitride and 316L stainless steel has been examined, with p-toluenesulphonic acid used as polymerization inhibitor, and it was found that mixes with higher powder volume fractions required higher levels of inhibitor. Assessment of the flow behaviour of several of the compositions showed them to be significantly non-Newtonian and the high viscosity of blends with a high loading of stainless steel suggests some premature polymerization. Measurement of green density of polymerized compacts demonstrated that high packing efficiency could be achieved. Thermogravimetry showed that rates of binder loss depended upon sample size and powder thermal conductivity. 相似文献
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Yin Liu Wei Lian Wanfu Su Juhua Luo Luming Wang 《International Journal of Applied Ceramic Technology》2020,17(1):205-210
With coal gangue and high alumina refractory solid wastes as raw materials, needle-like mullite powder, with an average diameter of about 1 μm, was synthesized at 1300°C by using the conventional solid-state reaction method. Mullite ceramics were derived from the inexpensive needle-like powder. Phase composition was examined by using X-ray diffraction (XRD), while morphologies of the ceramics were observed by using scanning electron microscopy. The content and distribution of elements in the sintered samples were characterized with energy dispersive spectrometer and X-ray fluorescence spectroscopy. Mechanical properties of the mullite ceramics were studied by using the three-point bending method. The aspect ratio of the needle-like mullite particles was up to 6. The mullite sample sintered at 1500°C for 3 hours had a density of 2.515 g·cm−3, which was slightly lower than the theoretical density. Maximum fracture toughness and bending strength of the mullite ceramics were 1.82 MPa·m1/2 and 71.76 MPa, respectively. This study realizes the resource utilization of gangue and high alumina refractory solid wastes, and the prepared mullite ceramics have good application prospect. 相似文献
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《应用陶瓷进展》2013,112(7):377-383
New ceramic foams have been successfully synthesised with coal gangue and waste quartz sand, which supply a feasible way to recycle these hazardous solid wastes. An objective of this research was to investigate the sintering behaviour and effects of sintering conditions on the crystalline phase change, microstructure and main properties of final ceramic foams. Good correlations among porosity, thermal conductivity, water absorption, bulk density, mechanical properties were studied. Results indicated that increasing sintering temperature or time had similar effects on the physical–mechanical properties. Samples sintering at 1140°C for 1 hour exhibited the highest porosity (87.5%), lowest bulk density (0.39?×?10?3?kg?m?3), lowest thermal conductivity (0.085?W·(m?K)?1), moderate water absorption (9.38%) and adequate flexible strength (2.4?MPa). Combined with excellent properties and low-cost characteristics, the new development for ceramic foams preparation will be widely used in building insulation materials for no-load bearing walls. 相似文献
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掌握煤中伴生有价微量元素在燃烧过程的迁移规律,对伴生元素的利用意义重大。选取4种高铝煤炭、1种煤泥和2种煤矸石等不同组成特性的样品为研究对象,采用逐级化学提取方法分析了锂(Li)、镓(Ga)和稀土(REE)在原料中的赋存形态,考察了以上元素在300~1100℃燃烧过程逸出情况和在燃烧灰中的富集行为,探讨了元素迁移规律与原料组成特性的关联。结果表明,Li、Ga和REE在7种样品中的赋存形态均以硅酸盐态为主,在燃烧过程的逸出率有与原料灰分呈负相关、与挥发分和含碳量呈正相关的趋势。以上元素在灰中均发生了不同程度的富集,REE的富集倍数高于Li和Ga。原料中微量元素含量和挥发分越高、灰分越低,同等燃烧条件下所得灰中微量元素的含量就越高。 相似文献
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Asmaa A. Negm Tarek Y. Elrasasi Hanem A. Khoder Fatma M. Metawe Mabrouk K. El-Mansy 《International Journal of Applied Ceramic Technology》2020,17(3):907-916
In the present study, sewage sludge ash (SSA) was added to clay to prepare lightweight ceramics for sustainable construction materials. The characterization and the effect of different concentrations of SSA on the physical and mechanical properties of the samples were studied. The results showed that the organic matter in SSA facilitated the combustion process. SSA addition reduced the bulk density from (1.94 to 1.32 g/cm3). Otherwise, the water absorption, the apparent porosity and the loss on ignition increased with the increase in SSA concentration. The addition of SSA lowered the compression strength but still within the standard range of the construction materials at concentration up to (30 wt.%). Furthermore, heavy metals are solidified inside the sintered samples, since Cu, Cd, Fe, Zn, Cr, Mn, Ni, and Pb, concentrations in the leachate met the range of Egyptian standard specification. 相似文献
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煤灰渣熔融特性的研究进展 总被引:18,自引:0,他引:18
煤灰的熔融特性不仅与煤灰的化学组成有关,还与灰成分的矿物形态有关,其中酸性氧化物可提高煤灰熔融温度,碱性氧化物却呈现降低煤灰熔融温度与助熔剂的作用。煤灰熔融温度与相平衡性质的良好相关性,可利用三元相图来预测和解释。据此通过添加不同助剂与煤灰中氧化物相互作用生成高熔点或低熔点物质的方法可改变煤灰熔融特性,以适应不同排渣方式和气化工艺的选择;同时将经碱盐催化气化后的煤灰添加适当助剂煅烧后可使其中形成玻璃网络的氧化物(如SiO2)与修饰中间氧化物(Al2O3、Fe2O3等)和修饰网络氧化物(Na2O、CaO、MgO等)相互作用形成新的稳定硅酸盐复合物,实现了含碱灰渣的煅烧脱碱无害化。 相似文献
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Chao Wang Shaohua Wang Xiaonv Li Yewei Liu Xiaozhen Zhang Qibing Chang Yongqing Wang 《International Journal of Applied Ceramic Technology》2021,18(3):1052-1062
Polished ceramic products are currently the most popular in architectural decoration, but a significant amount of ceramic polishing waste (CPW) is produced during the preparation process. Determining how to handle the CPW is a pressing task for enterprises. This work investigated the feasibility of recycling CPW in porcelain tile, and its influence on the phase composition, microstructure, and properties of the ceramic body. The CPW was found to have a similar composition to the traditional ceramics and worked as a flux. The SiC within CPW began to decompose into SiO2 with CO2 generation at about 1100°C, resulting in a porous structure. Microstructure observation indicated that a high CPW sample produced sufficient liquid phase when fired at temperatures ≤1100°C, which was not only beneficial for mullite growth but also for matrix densification by the viscous flow mechanism. But a high-content CPW caused the body to foam or even expand at temperatures >1100°C, thus significantly reducing mechanical properties. Finally, a series of porcelain tiles were successfully prepared with a CPW content of ≤30 wt% at a firing temperature of 1125-1200°C. The results of this study are considered to be valuable for the utilization of CPW. 相似文献
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《Ceramics International》2022,48(14):19542-19556
Fiber reinforced ceramic matrix composites (FRCMCs) have been used in various engineering fields. Additive manufacturing (AM) technologies provide new methods for fabricating FRCMCs and their structures. This review systematically reviews the additive manufacturing technologies of FRCMCs. In this review, the progress for additive manufacturing of FRCMCs were summarized firstly. The key scientific and technological challenges, and prospects were also discussed. This review aims to motivate the future research of the additive manufacturing of FRCMCs. 相似文献
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Jun Yu Feng-Xiu Yu Shan Wang Jie-Feng Zhang Feng-Qiang Fan Qiang Long 《Ceramics International》2018,44(15):17630-17634
ZrO2@Al2O3 composite ceramic powders were prepared by solution combustion method with aluminum nitrate (Al (NO3)3) and 3?mol% yttria-stabilized tetragonal zirconia polycrystal (3Y- TZP) as the main raw materials, ammonium polyacrylate (PAA-NH4) as a dispersant, urea (CO (NH2)2) as a reducing agent. The effects of PAA-NH4 concentration and drying method on the microstructure and morphology of the ZrO2@Al2O3 powders were investigated. The results showed that when the concentration of PAA-NH4 was 1.5?wt%, and the molar ratio of Al (NO3)3 to CO (NH2)2 was 1:2, the ZrO2@Al2O3 powders with uniform grain size and high crystallinity could be synthesized by solution combustion drying method. Additionally, the abnormal growth of 3Y- TZP grain in ZrO2@Al2O3 was suppressed and the crystalline phase transformation trend (t-ZrO2 to m-ZrO2) was obviously decreased after sintering at 1600?°C. 相似文献
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Donghai Ding Yufei Fang Guoqing Xiao Xianfeng Zhu Pengcheng Fu Xiaochuan Chong 《International Journal of Applied Ceramic Technology》2021,18(5):1832-1844
Low density and high strength ceramic proppant was prepared by sintering high aluminium type low-grade bauxite and high iron type low-grade bauxite at the temperature range from 1300℃ to 1360℃. The phase composition and micromorphology of ceramic proppant were, respectively, characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The bulk density, apparent density, and breakage ratio of ceramic proppant were tested using standard methods. The results show that mullite crystal and corundum crystal are fully developed, the spatial network structure of rod-shaped mullite is formed, and corundum crystal is evenly distributed in the sample when the sintering temperature is 1340℃. At this temperature, the bulk density of the sample is 1.42 g/cm3, the apparent density is 2.67 g/cm3, and the breakage ratio is 5.1% under the closure pressure of 52 MPa. Then, the growth mechanism of mullite crystal in ceramic proppant was explored. The results reveal that the mullite crystal in ceramic proppant conforms to the layer growth theory. The secondary crystal nucleus is formed in the growth process and shows a step growth mechanism. With the increase in sintering temperature, the preferred orientation growth of mullite crystal finally forms needle-like morphology. 相似文献
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深层、低渗透、高闭合压力储层将是未来油气田水力压裂的主要区域,陶粒支撑剂因在水力压裂作业中起到支撑裂缝、提高导流率、增加油气产量的作用而备受关注。随着高品位铝矾土资源日渐枯竭,低铝质原料成为制备陶粒支撑剂的主要原料,目前主要包括低品位铝矾土、硅铝质固体废弃物以及其他材料。本文在总结大量文献的基础上,阐述了低铝质原料制备陶粒支撑剂所具有的优势以及存在强度不足的缺陷。之后针对这一问题,文章提出了覆膜增强和添加剂增强两种增强方式,系统讨论了预固化覆膜增强、可固化覆膜增强、液相助熔增强和畸化晶格增强对陶粒支撑剂强度的影响,总结出针对于不同原料制备、不同应用环境下的陶粒支撑剂最佳的增强方式。最后对陶粒支撑剂未来潜在发展方向进行了展望。 相似文献
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综合分析了我国在煤矸石综合利用方面的工业化进展。我国循环流化床煤矸石发电技术已引领国际先进发展水平,已开始发展超临界和超超临界煤矸石发电技术;全煤矸石烧结砖装备技术也达到国际先进水平,单套设备生产能力达到年消纳百万吨煤矸石;大规模利用煤矸石进行充填采空区和塌陷区、筑基修路、土地复垦等成为煤矸石无害化处理的主要方式。煤矸石的综合处理能力超过4亿吨/年。然而相对于煤矸石巨大的产生量,现有利用途径仍难以满足其处理需求。高附加值利用是煤矸石综合利用的重要补充,将成为煤矸石综合利用的发展方向。基于目前高附加值利用的发展现状,构建了煤矸石高附加值利用的循环经济路线,对于进一步提高其资源利用水平和利用率有重要意义。 相似文献
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泡沫碳化硅陶瓷材料除了孔隙率高、比表面积大,还具有相对密度小、优良的热学、力学、电学、声学性能等特性,已经广泛应用于化工、机械、生物、环保等领域。本文总结了泡沫碳化硅陶瓷材料的主要制备技术,包括粉末烧结法、固相反应烧结法、含硅树脂热解法以及气相沉积法等。阐述了泡沫碳化硅陶瓷材料的几种优良特性,包括结构特征、流体阻力、抗氧化性、吸波性等。最后举例介绍了该陶瓷在催化、过滤、生物学等领域的应用现状,重点介绍了其作为塔内件在化工领域中的应用,指出为满足对泡沫碳化硅陶瓷更高性能的需求,不仅要对现有技术进行集成创新,更要挖掘和开发泡沫碳化硅的潜在优势。 相似文献