METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
·
2020
·Vol. 51
·期 10
·5328-5338
·
IF 2.05
Zou Yongshun,Gu Huazhi,Huang Ao,Fu Lvping
Sintered magnesia refractories combined by in situ intergranular CaZrO 3 phases were synthesized using natural MgO-containing natural minerals with CaO and SiO 2 impurities and nano-sized ZrO 2 additive. A homogenous distribution of intergranular CaZrO 3 , independent from the intergranular CaO-MgO-SiO 2 phases, was formed in situ within the sintered magnesia aggregates by introducing 0.75 wt pct nano-sized ZrO 2 into the magnesite. The formation mechanism of the in situ intergranular CaZrO 3 phases was determined. The nano-sized ZrO 2 was introduced and uniformly distributed at grain boundaries of the magnesia due to the micron-nano-sized particles composite system and wetting grinding process. Then the CaO in impurities were prior to SiO 2 to react with the ZrO 2 for generating CaZrO 3 at the grain boundaries by increasing sintering temperature. Nevertheless, the nano-sized ZrO 2 particles were encapsulated in the MgO crystallites with similar particle size decomposed from brucite and prevented from reacting with CaO impurities in magnesite. The mixing homogeneity of magnesite particles and ZrO 2 particles and the direct contact between ZrO 2 and CaO impurities in magnesite has a crucial effect on the formation of intergranular CaZrO 3 phases. Furthermore, the intergranular CaZrO 3 phases could enhance the bonding of magnesia grains and have great potential for improving the service performance of magnesia.
研究领域:
材料科学
·
无机非金属材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL
·
2023
·Vol. 30
·期 10
·2021-2030
·
IF 2.5
Liu Hao,Zhu Yu-xuan,Wang Zhou-fu,Ma Yan,Wang Xi-tang
Magnesia castables have been widely used in metallurgical industries with the advantages of high refractoriness, non-polluting steel, and resistance to alkaline slag. Magnesia castables were prepared using strontium carbonate (SrCO 3 ) as additive to enhance slag resistance and mechanical properties, and the influence of SrCO 3 on the evolution of phases, microstructure and properties of magnesia castables sintered at different temperatures was clarified. The results show that, with the introduction of SrCO 3 (lower than 3 wt.%), elastic modulus, mechanical strength, thermal shock resistance and densification of magnesia castables were significantly enhanced owing to the formation of needle-like Ca 0.9 Sr 0.1 MgSi 2 O 6 phase and liquid phase when sintering at high temperatures, and the introduced SrCO 3 presented minor effects on the mechanical properties of castables for its highly structural stability below 1100 °C. During the slag corrosion process, SrCO 3 and SiO 2 in castables reacted with Al 3+ in molten slag to form SrAl 2 SiO 8 phase, resulting in the increased slag viscosity and suppressed continuing penetration.
研究领域:
材料科学
·
冶金工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Cheng Yuan,Yu Liu,Guangqiang Li,Yongshun Zou,Ao Huang
The microporous refractory with low thermal conductivity shows a promising application prospect as tundish lining. In this study, the interactions between microporous magnesia aggregates and oxide inclusions in steel were explored. The experimental results and thermodynamic calculation show that the interaction process of microporous magnesia aggregates and oxide inclusions at high temperature can be divided into dissolution, reaction and post-reaction. The microporous magnesia aggregates can absorb the inclusions in steel by reaction and liquid phase penetration. The microporous magnesia aggregates have a strong adsorption for Al 2 O 3 and TiO 2 . Moreover, the microporous magnesia aggregates mainly absorb SiO 2 by penetration, but excessive SiO 2 will lead to the serious corrosion of microporous magnesia aggregates.
研究领域:
材料科学
·
冶金工程
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 39
·59502-59512
·
IF 5.19
Liang Hai,Guo Panliang,Yang Yunhong,Wang Wanting,Sun Zhaonan
Herein, magnesite slags (MS), which remain after sulfuric acid extraction from light burnt magnesite in the magnesite industry, were used as phosphate adsorbents in wastewater. The MS were calcined under 700 °C to enhance phosphate adsorption. The calcined magnesite slags (CMS) were characterized by nitrogen adsorption–desorption isotherm, X-ray diffraction, and scanning electron microscopy. A series of batch adsorption experiments were carried out to test the phosphate adsorption capacity of CMS. The results showed that the calcific treatment promoted the conversion from Mg, Ca, Fe, etc. compound to metal oxide of the MS. The generated metal oxide particles resulted in 237.4 mg/g increase in the phosphate adsorption capacity. The phosphate adsorption isotherm of CMS fitted the Langmuir model better, and the maximum adsorption capacity of CMS was 526 mg/g. The adsorption kinetics of phosphate on CMS can be described by the pseudo-second-order model. The phosphate removal efficiency was greater than 98% in 300 mg/L phosphate solution. Mechanism investigation results indicated that phosphate was adsorbed by CMS through MgO protonation, electrostatic attraction, Mg-P complexation, and ligand exchange. The results obtained in this work demonstrate that the CMS is a potential effective adsorbent for removal and reutilization phosphate from P-contaminated water, due to it can be employed as a fertilizer after phosphate adsorption. Graphical abstract
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CORROSION SCIENCE
·
2019
·
IF 6.355
Lvping Fu,Huazhi Gu,Ao Huang,Yongshun Zou,Hongwei Ni
Lightweight materials containing nano-sized intracrystalline pores are reported, and their slag reaction behaviours are described. The introduction of nano-sized intracrystalline pores favouring the supersaturation of molten slag and the precipitation of solid phases at the reaction interfaces, and the isolation layer can prevent lightweight materials from further slag corrosion and penetration. Because the alumina materials have higher purity and a tight grain-bonding, they show the highest slag resistance. The impurities located between the grains are responsible for the deeper slag penetration of bauxite and magnesia materials. Moreover, the intergranular phases in the magnesia materials are interconnected, resulting in severe slag corrosion.
研究领域:
材料科学
·
腐蚀工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）