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Luoyang, China

Yu R.,Henan University of Science and Technology | Du P.,Henan University of Science and Technology | Zhou N.,Henan University of Science and Technology | Li C.,Sinosteel Refractory Co.
China's Refractories | Year: 2013

In order to enhance performance of pre-cast shapes of alumina based castables, the present work explored the approach of forming in-situ bonding phases by incorporating Si powders and then heating in carbon embedded atmosphere. Using tabular alumina as aggregates, tabular alumina, SiC powders, Si powders, calcium aluminate cement, microsilica and ultrafine a-Al 2O3 powders as matrix, alumina based ultra low cement (ULC) castables were prepared. Influences of Si powder addition at 0, 4%, 6%, 8% and 10% (in mass) on regular properties, cold modulus of rupture (CMOR), hot modulus of rupture (HMOR), thermal shock resistance (TSR) and microstructure of the castables after carbonization were investigated. After incorporation of Si powders and carbon embedded heating, the in-situ mullite and nonoxide phases such as SiAlON and SiC can be formed by oxidation, nitridation or carbonization reaction. HMOR and TSR of the castables with in-situ nonoxides bonding are obviously improved. After carbon embedded heating, the HMOR at 1 400 °C increases from 1. 6 MPa to 8. 3 MPa, and the residual CMOR ratio after thermal shock increases from 64. 9% to 137. 9% when Si addition increases from 0 to 10%. Source


Ren F.,Henan University of Science and Technology | Ren F.,Sinosteel Refractory Co. | Ren F.,University of South Florida | Ma Z.,Henan University of Science and Technology | Tian B.,Henan University of Science and Technology
Journal of Ceramic Processing Research | Year: 2014

Polyurethane foam was used as a precursor for fabricating SiC-based ceramic foam filters. Two recoating slurry processes were adopted to enhance the strength of ceramic foam. One was the recoating slurry of stoved green body and another was the recoating slurry of pre-sintered green body. The differences in weight increase and thermal shock resistance of ceramic foams fabricated by the two recoating slurry processes were investigated. The effects of pre-sintering temperature on weight increase and thermal shock resistance are discussed. Thermal shock resistance of ceramic foams fabricated by two recoating slurry processes is lower than that by the single coating slurry process. Compared with recoating slurry of pre-sintered green bodies, with the same slurry, the weight increase of ceramic foams fabricated by recoating slurry of the stoved green bodies is less, but the number of thermal cycles to failure is much higher. For ceramic foams fabricated by recoating slurry of presintered green bodies with the same slurry, the weight increase and the number of thermal cycles to failure decreased with the pre-sintering temperature. © 2004 Hanyang University. All right reserved. Source


Zhang D.,Xian University of Architecture and Technology | Zhang D.,Sinosteel Refractory Co. | Jiang M.,Xian University of Architecture and Technology | Xiao G.,Xian University of Architecture and Technology | Huang S.,Xian University of Architecture and Technology
China's Refractories | Year: 2012

Magnesia chrome bricks were prepared with fused MgO - Cr2 O3 synthesized material, fused magnesite and chrome ore as main starting materials. Nano-Al203 was added into refractories (2%, 4% and 6% in mass) substituting for A12O3 micropowder. After mixing and shaping, the bricks were fired at 1 550 ° C, 1 600° C, 1 650 t and 1 750 t, respectively. The microstruc-ture, sintering property, mechanical properties, thermal shock resistance and slag resistance of the specimens with the addition of nano-Al203 were investigated. The results indicate that the performance of brick with 4 mass% of nano-Al203 is greatly improved after firing at 1 650° C. Source


Wang L.,Xian University of Architecture and Technology | Wang L.,Sinosteel Refractory Co. | Jiang M.,Xian University of Architecture and Technology
China's Refractories | Year: 2012

High temperature oxidation behavior of two kinds of nitride bonded SiC based refractories was investigated at 1100-31500 °C by means of X-ray diffractometer, scanning electronic microscopy and thermogravimetry. The results show that: (1) with the temperature increasng, the oxidation mass increment rate of the specimen ncreases first and then decreases, and oxidation passivation occurs; (2) the oxidation resistance of SiAlON bonded SiC refractories is superior to that of Si 3N 4 bonded SiC refractries; (3) high temperature oxidation results in the increase of compressive strength at room temperature of SiC based refractories compared with specimen before oxidation; the compressive strength of SiAlON bonded SiC specimens oxidized at high temperatures decreases with the increase of the temperature as a result of formation and burst of surface bubble, while the decrease of compressive strength of Si 3N 4 bonded StC specimens oxidized at high temperatures is owing to the increase of the consistency of net-like crack associated with cristob-alite transformation during cooling. Source


Jia T.,Luoyang Institute of Science and Technology | Jia T.,Henan Polytechnic University | Min Z.,Luoyang Institute of Science and Technology | Cao J.,Henan Polytechnic University | And 4 more authors.
Journal Wuhan University of Technology, Materials Science Edition | Year: 2015

SnS2 nanoflakes were successfully synthesized via a simple hydrothermal process. The as-prepared SnS2 samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherms, and UV-vis diffuse reflectance spectroscopy (DRS). The photocatalytic activities of the as-prepared SnS2 nanoflakes under visible light irradiation (λ>420 nm) were evaluated by the degradation of rhodamine B (RhB). The effect of hydrothermal temperatures on the photocatalytic efficiency of as-prepared SnS2 nanoflakes was investigated. The experimental result showed that SnS2 nanoflakes synthesized at the temprature of 160° had higher photocatalytic efficiency and good photocatalytic stability. © 2015, Wuhan University of Technology and Springer-Verlag Berlin Heidelberg. Source

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