The technology and properties of sponge city permeable bricks prepared using refractory waste

Jieguang Song,Xueqing Yang,Ping Chen,Rongjin Liu,Deping Luo,Yuxuan Wei,Wenjin Yao,Jingjing Liu,Qing Zeng 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.4

With the widespread development of sponge city projects across the country, the use of industrial permeable bricks hasincreased dramatically. My country produces a large amount of refractory waste and pollutes the environment seriously. Wasterefractory insulation bricks are used as the main raw materials, and a small amount of auxiliary raw materials are added toprepare sponge urban permeable bricks through forming and sintering processes. Through performance tests, such asporosity, flexural strength, and water permeability coefficient, the effect of process parameters on the performance ofpermeable bricks is studied, the process parameters of using refractory waste are comprehensively optimized to preparesponge urban permeable bricks, and permeable bricks are prepared for the industrialization of high-quality industrial solidwaste. Brick provides reference. Through the experimental results and analysis, the following conclusions are drawn: the rawmaterial ratio of refractory brick waste: binder: foaming agent: sintering aid is 80:10:1:9. Slurry water mill foaming occurswhen the water to material ratio is 0.5, the ball milling speed is 80 r/min, and the ball milling time is 2 h; the foaming effectand molding performance are better. In the drying stage, drying at 45 oC for 12 h has the best molding effect. The sinteringsystem at 1,300 oC and holding time of 1 h has the best sintering performance. After optimizing the process, the porosity ofthe permeable bricks can reach 48.4%, the water permeability coefficient is 2.1×10^-2 cm/s, the national permeable brick hasA-level standard, and the compressive strength is 26.8 MPa.

Sintering densification and properties of Al2O3/Al cermet materials via powder metallurgy method

Jieguang Song,Yue Liu,Cailiang Pang,Jia Zhang,Lin Chen,Xiling Zhang,Songlin Guo,Xianzhong Wang,Ruihua Wang,Aixia Chen 한양대학교 세라믹연구소 2018 Journal of Ceramic Processing Research Vol.19 No.2

Cermet materials are important new engineering materials with combined advantages of ceramics and metals. In this study,Al2O3/Al cermet materials were prepared through powder metallurgy. The effect of sintering technology on the properties ofAl2O3/Al cermet materials was analyzed as basis for preparing high-performance cermet materials. Results showed that whenthe sintering temperature was increased from 700 oC to 1000 oC under holding time for 1 h, the densification degree and hardnessof Al2O3/Al cermet materials decreased and the electric resistivity increased. In the microstructure of Al2O3/Al cermet materials,Al particles were larger and continuously distributed, whereas the Al2O3 particles were smaller and discontinuously distributed. When the holding time was increased under sintering temperature of 700 oC, the densification degree and hardness of Al2O3/Alcermet materials also increased, and the electric resistivity decreased. When 25 wt% Al2O3/Al cermet materials were sintered at700 oC for 3 h, the densification degree was higher, with hardness of 2203 HV and electric resistivity of 0.0159 Ω • m.

Preparation and properties of Al-Al2O3 metal ceramics via powder metallurgy methods

Jieguang Song,Xiuqin Wang,Lin Chen,Cailiang Pang,Jia Zhang,Weiguo Shi,Songlin Guo,Xianzhong Wang,Ruihua Wang 한양대학교 세라믹연구소 2018 Journal of Ceramic Processing Research Vol.19 No.1

Metal ceramics are outstanding new engineering materials that offer the advantages of both ceramics and metals. In this study,Al-Al2O3 metal ceramics were prepared through powder metallurgy methods, and the densification and properties of theprepared metal ceramics were investigated to gain insights into the preparation of high-performance cermet materials. Resultsrevealed that as the forming pressure was increased, the relative density of the ceramics increased, whereas their electricalresistivity decreased. The relative density increased with increasing sintering temperature up to 700 oC and decreased beyond700 oC, whereas the electrical resistivity exhibited an opposite trend. The relative density increased with increasing Al content,whereas the electrical resistivity displayed an opposite trend. Under optimal technological parameters of 700 oC sinteringtemperature, < 20MPa forming pressure, and 75 wt% Al content, Al-Al2O3 metal ceramics with a high relative density(97.52%) and a low electrical resistivity (101.34 Ω·m) were successfully prepared.

The effect of the sintering temperature on the properties of porous YAG ceramics

Jieguang Song,Lin Chen,Cailiang Pang,Jia Zhang,Weiguo Shi,Songlin Guo,Xianzhong Wang,Minghan Xub 한양대학교 세라믹연구소 2018 Journal of Ceramic Processing Research Vol.19 No.1

Pure yttrium aluminum garnet (YAG) powders and the porous YAG ceramics were prepared via co-precipitation method andusing vacuum sintering technology, respectively. Through an analysis and discussion, porous YAG ceramics, with ahomogeneous and regular pore microstructure, a pore size of about 5 μm, regular crystalline particles, showing intergranularfracture, were sintered at 1500 oC. Porous YAG ceramics, with a homogeneous and regular pore microstructure, a pore sizefor about 2-5 μm, crystals with a rod-shape or acicular structure, showing intergranular fracture and intracrystalline fracture,were sintered at 1550 oC. Porous YAG ceramics, with an extension pore microstructure, a crystalline laminate structure,showing intracrystalline fracture, were sintered at 1600 oC. With an increase in the sintering temperature, the porosity isdecreased gradually and the energy consumption is increased. The best sintering temperature for porous YAG ceramics wasdecided to be 1550 oC through considering the performance price ratio among the porosity, the mechanical properties and theenergy consumption.

Influence of raw materials ratio on performance of permeable bricks made from electric porcelain waste

Jieguang Song,Xueqing Yang,Ping Chen,Hao Xu,Deping Luo,Rongjin Liu,Zhijun Lai 한양대학교 세라믹연구소 2022 Journal of Ceramic Processing Research Vol.23 No.4

The prepared permeable bricks using electric porcelain waste as the main raw material are investigated, which improves theutilization rate of electric porcelain waste, and realizes the organic unity of recycling resource and ecological environmentprotection. The effects of different raw material ratios on the permeability coefficient, apparent porosity, compressive strength,volume shrinkage rate and microstructure properties of electric porcelain waste permeable bricks are investigated. The electricporcelain waste with a ratio of over 85 wt.% have greatly improved the utilization rate of electric porcelain waste. The resultsare shown that the water-to-material ratio or foaming agent content are increased, the porosity and water permeability of theelectric porcelain waste permeable brick are increased, but the compressive strength of the electric porcelain waste permeablebrick is decreased. The 90 wt.% electric porcelain waste, the 3 wt.% kaolin, the 5 wt.% sintering aid, and the 2 wt.% foamingagents are optimum raw materials ratios, the water-to-material ratio for 0.9 and the drying temperature at 40 oC, the sinteringtemperature at 1200 oC and holding time for 1 h are obtained the excellent performance electric porcelain waste permeablebricks. The permeability coefficient is 3.9×10−2 cm/s, the volume shrinkage rate is 37.88%, the compressive strength is 1.146MPa, and the porosity is 79.0%.

Fabrication and properties of Al2O3-Al cermet materials using different raw material composition parameter

Jieguang Song,Yue Liu,Chunxiao Wu,Xueqing Yang,Yipeng Gong,Jianzhen Huang,Chunyan He,Huihui Luo,Aixia Chen 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.1

Cermet application is extensive because it retains the characteristics of ceramic materials and has the advantages of metalmaterials. In this paper, alumina/aluminum cermet materials were prepared through powder metallurgy method. Theinfluence of raw material formula on the properties of alumina/aluminum cermet was investigated on the basis that ceramicmaterials have good wear resistance and high thermal conductivity. Results show that when the mass ratio of alumina toaluminum is 1:3, the prepared cermet samples have excellent properties, highest density, and uniform distribution ofaluminum and alumina. MgO addition exhibits better effect, higher degree of densification, and renders higher hardness andstrength for the sample as compared with SiO2 and Y2O3 addition. The sintered cermet with composite powder prepared viaprecipitation has better properties and higher densities and surface hardness than that prepared via the ball mill method. Therelative density was 97.1%, surface hardness was 875 HV, and electric resistance was 0.0169 Ω·m.

Preparation and properties of coated silica/aluminum cermet materials via powder metallurgy method

Jieguang Song,Yue Liu,Chunxiao Wu,Xueqing Yang,Huihui Luo,Chunyan He,Chengbin Li,Haizhen Yang 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.2

Cermet is a combination of metal and ceramic, it exhibits some special properties, so it is one of the most widely usedengineering materials. In this paper, the properties of encapsulated SiO2/Al cermet were prepared by powder metallurgymethod. Results showed that the density of SiO2/Al cermet is increased with an increasing Al content. When the Al contentis high, and the high temperature is sintered, the liquid phase can fully bond the surrounding SiO2 particles to form a relativelycontinuous and dense structure, thereby obtaining a high microstructure density. When the SiO2:Al ratio is increased from 1:1to 1:3, the hardness is gradually increased. The hardness and density of the sample are gradually increased with an increasingmolding pressure. The surface hardness of the cermet is increased first and then decreased with an increasing sinteringtemperature. When the SiO2:Al ratio is 1:3, the holding time is 10 min under molding pressure of 15 MPa, and the sinteringtemperature is 900 °C for 1 h, the surface hardness of the obtained coated SiO2/Al cermet is high, the value is 175.2 HV.

Synthesis and properties of ultrafine YAG powder via low-temperature microwave hydrothermal method

Yue Liu,Jieguang Song,Lin Chen,Huihui Luo,Guojian Lin,Peng Chen,Chenhui Wei,Jingjing Liu 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.4

Yttrium aluminum garnet (YAG) has good optical properties and has been widely used in engineering. The preparation ofconventional YAG powder is costly due to its high synthesis temperature, so lowering the synthesis temperature is the mosteffective way to save cost. The ultrafine oxide composite powder was rapidly synthesized using the microwave hydrothermalmethod at a low temperature. The effect of temperature and its performance. Differential thermal analysis and XRD phaseanalysis showed the mixed solution of Al(NO3)3 and Y(NO3)3 at pH=9 and C(Al3+)=0.42 mol·L−1. SEM, zeta potential, andparticle size analysis revealed that the microwave hydrothermal reaction temperature was 170 oC, and the high-purityultrafine YAG powder was calcined at 928 oC, which was lower than conventional calcination temperature. The synthesizedultrafine spherical YAG powder had a small particle size and a uniform distribution.

Sintering technology and properties of sponge city permeable bricks prepared from electrical porcelain was

Yue Liu,Yun Xiang,Jieguang Song,Dongliang Zhang,Hongbin Wen,Yuzhen Wang 한양대학교 청정에너지연구소 2022 Journal of Ceramic Processing Research Vol.23 No.6

The generated electric porcelain waste increases with the rapid development of the electric porcelain industry. Unreasonableutilization results in the waste of resources and environmental pollution. However, at present, many coal gangues and fly ashesare wasted and underutilized in my country. In this paper, electric porcelain waste is used as the main raw material, and itssintering temperature, holding time, and heating rate are discussed to study the performance of the permeable brick preparedfrom electric porcelain waste. Results show that with the increase in sintering temperature, the porosity and waterpermeability coefficient of permeable bricks decrease, and their volume shrinkage rate and compressive strength show anincreasing trend. Furthermore, porosity decreases with the increase in holding time. The volume shrinkage rate andcompressive strength increase, and the water permeability coefficient decreases. The volume shrinkage rate of the permeablebrick decreases, and its porosity, water permeability coefficient, and compressive strength increase with the heating rate. Combined with the comprehensive consideration of the porosity, volume shrinkage rate, water permeability coefficient, andcompressive strength of permeable bricks, the best sintering process for preparing permeable bricks from electrical porcelainwaste is presented with a sintering temperature of 1225 °C, holding time of 1 h, and heating rate of 6 °C/min. The porosityof the prepared permeable brick is 79.5%, the volume shrinkage rate is 25.79%, the water permeability coefficient is 2.82×10-2cm/s, and the compressive strength is 5.79 MPa.

Microstructure and mechanical properties of yttrium aluminum garnet porous ceramics prepared by different sintering process parameters

Yue Liu,Xueqing Yang,Kangliang Peng,Qiong Wang,Jianzhen Huang,Zilin Zhang,Jiang Lu,Hao Xu,Jieguang Song,Lin Chen 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.4

Yttrium aluminum garnet (YAG), which possesses excellent properties, is investigated and applied. The sintering technology of YAG porous ceramics is optimized. Results show that the porosity initially increases and then decreases with an increase of increasing temperature rate, the porosity are decreased with an increase of removing carbon temperature, the porosity are decreased with an increase of sintering temperature, the porosity are decreased with an increase of holding time. Meanwhile, the compressive strength constantly exhibits an opposite tendency. The optimization of the sintering technology of YAG porous ceramics is based on porosity and compressive strength. A good sintering technology are an increasing temperature rate of 8 oC/min, a removing carbon temperature of 800 oC, removing carbon time of 1 h, a sintering temperature of 1450 oC and holding time of 2 h. The porosity of the prepared YAG porous ceramics is 57.4%, and the compressive strength is 8.89 MPa.