Two types of low carbon MgO - C refractories with 6% graphite were prepared using microporous magnesiarich spinel （5 - 3 and 3 - 1 mm ） and fused magnesia （5 - 3 and 3 - 1 mm ） as coarse aggregates, respectively, ...Two types of low carbon MgO - C refractories with 6% graphite were prepared using microporous magnesiarich spinel （5 - 3 and 3 - 1 mm ） and fused magnesia （5 - 3 and 3 - 1 mm ） as coarse aggregates, respectively, fused magnesia （ ≤1 mm） as fine aggregate, magnesia powder （≤ 0. 088 mm ） , flake graphite powder （ ≤0. 088 mm）, metal Al powder （ 〈0. 074 mm） as matrix, and phenol resin as binder. After curing at 220 ℃ and coke-embedded firing at 1 500 ℃ , the apparent porosity, cold crushing strength, cold modulus of rupture, permanent linear change on heating, thermal shock resistance and slag resistance of the specimens were studied comparatively. The results indicate that： （ 1 ） after curing at 220 ℃ and coke-embedded firing at 1 500 ℃, the specimen with microporous magnesia-rich spinel replacing fused magnesia has lower bulk density and higher apparent porosity than the common low car- bon MgO - C specimen. After curing at 220 ℃, the specimen with microporous aggregate has lower strength than common low carbon MgO - C specimen, but after coke-embedded firing at 1 500℃, it has higher strength and lower permanent linear change on heating; （2） low carbon MgO - C specimen using microporous magnesia-rich spinel to replace fused magnesia aggregate has better thermal shock resistance but worse slag resistance.展开更多
To meet the needs of environmental protection and promote the application of chromium-free refractories for RH refining furnaces, research on application of new non-burned periclase-magnesia alumina spinel bricks was ...To meet the needs of environmental protection and promote the application of chromium-free refractories for RH refining furnaces, research on application of new non-burned periclase-magnesia alumina spinel bricks was carried out. Through laboratory research and field application, it is concluded that the non-burned periclase-magnesia alumina spinel brick can replace magnesia-chrome material, and its service life is equivalent to that of the magnesia-chrome material with reduced cost.展开更多
Carbon nanotubes （CNTs） have been extensively studied over the last two decades since they possess excellent properties.CNTs have been considered as new promising reinforcements for carbon containing refractories （...Carbon nanotubes （CNTs） have been extensively studied over the last two decades since they possess excellent properties.CNTs have been considered as new promising reinforcements for carbon containing refractories （CCRs）.Current research progress of the CNT-reinforced MgO-C and Al2O3-C refractories was summarized in this mini-review,and the CNT-reinforced CCRs possess remarkable mechanical properties and superior thermal shock resistance compared to CCRs without CNTs.展开更多
The paper analyzed the recycle condition and developing trend of used refractories China and other countries, irwluding research achievements of recycles of used refractories such as MgO-C bricks, Al2O3-MgO-C brics, A...The paper analyzed the recycle condition and developing trend of used refractories China and other countries, irwluding research achievements of recycles of used refractories such as MgO-C bricks, Al2O3-MgO-C brics, Al2O3-SiC-C castable and MgO-Cr2O3 bricks. Recycled refractories exhibit the same or even better properties as compared with the original. In addition, prospects for recycle of used refractories are also discusseded.展开更多
Regarding the morphology of alumina,effect of the heredity of raw materials on properties of aluminamagnesia refractory castables was investigated by adding platelet alumina as the specific template.In-situ spinel pla...Regarding the morphology of alumina,effect of the heredity of raw materials on properties of aluminamagnesia refractory castables was investigated by adding platelet alumina as the specific template.In-situ spinel platelet formed derived from platelet alumina.By comparing phase evolution,apparent porosity,bulk density,permanent linear expansion and strength,it was demonstrated that the utilization of the microstructures＇ heredity of platelet alumina was a new alternative for controlling properties of alumina-magnesia refractory castables.展开更多
The corrosion behavior of alumina-chromia refractory against two kinds of industrial slags （coal slag and iron smelting slag） at 1550℃ was investigated via thermodynamic simulations. In the proposed simulation mode...The corrosion behavior of alumina-chromia refractory against two kinds of industrial slags （coal slag and iron smelting slag） at 1550℃ was investigated via thermodynamic simulations. In the proposed simulation model, the initial slag first attacks the matrix and surface aggregates and subsequently attacks the inner aggregates. The simulation results indicate that the slag chemistry strongly affects the phase formation and corrosion behavior of the refractory brick. Greater amounts of alumina were dissolved and spinel solid phases formed when the brick interacted with iron smelting slag. These phenomena, as well as the calculated lower viscosity, may lead to much deeper penetration than that exhibited by coal slag and to more severe corrosion compared to that induced by coal slag. The thermodynamic calculations well match the experimental observations, demonstrating the efficiency of the proposed simulation model for evaluating the corrosion behavior of alumina-chromia refractory.展开更多
MgO·Al 2O 3 spinel fibers may be obtained by thermal treatment of pressed specimens composed of Mg-Al-O materials with appropriate oxide-metal ratio at high temperature under controlled atmosphere. Their phase ...MgO·Al 2O 3 spinel fibers may be obtained by thermal treatment of pressed specimens composed of Mg-Al-O materials with appropriate oxide-metal ratio at high temperature under controlled atmosphere. Their phase composition and microstructure have been examined.展开更多
文摘Two types of low carbon MgO - C refractories with 6% graphite were prepared using microporous magnesiarich spinel （5 - 3 and 3 - 1 mm ） and fused magnesia （5 - 3 and 3 - 1 mm ） as coarse aggregates, respectively, fused magnesia （ ≤1 mm） as fine aggregate, magnesia powder （≤ 0. 088 mm ） , flake graphite powder （ ≤0. 088 mm）, metal Al powder （ 〈0. 074 mm） as matrix, and phenol resin as binder. After curing at 220 ℃ and coke-embedded firing at 1 500 ℃ , the apparent porosity, cold crushing strength, cold modulus of rupture, permanent linear change on heating, thermal shock resistance and slag resistance of the specimens were studied comparatively. The results indicate that： （ 1 ） after curing at 220 ℃ and coke-embedded firing at 1 500 ℃, the specimen with microporous magnesia-rich spinel replacing fused magnesia has lower bulk density and higher apparent porosity than the common low car- bon MgO - C specimen. After curing at 220 ℃, the specimen with microporous aggregate has lower strength than common low carbon MgO - C specimen, but after coke-embedded firing at 1 500℃, it has higher strength and lower permanent linear change on heating; （2） low carbon MgO - C specimen using microporous magnesia-rich spinel to replace fused magnesia aggregate has better thermal shock resistance but worse slag resistance.
文摘To meet the needs of environmental protection and promote the application of chromium-free refractories for RH refining furnaces, research on application of new non-burned periclase-magnesia alumina spinel bricks was carried out. Through laboratory research and field application, it is concluded that the non-burned periclase-magnesia alumina spinel brick can replace magnesia-chrome material, and its service life is equivalent to that of the magnesia-chrome material with reduced cost.
基金financially supported by the National Natural Science Foundation of China ( General program,51272188, 51472184 and 51472185 )the Natural Science Foundation of Hubei Province,China ( Contract No. 2013CFA086 )Foreign Cooperation Projects in Science and Technology of Hubei Province,China ( Contract No. 2013BHE002)
文摘Carbon nanotubes （CNTs） have been extensively studied over the last two decades since they possess excellent properties.CNTs have been considered as new promising reinforcements for carbon containing refractories （CCRs）.Current research progress of the CNT-reinforced MgO-C and Al2O3-C refractories was summarized in this mini-review,and the CNT-reinforced CCRs possess remarkable mechanical properties and superior thermal shock resistance compared to CCRs without CNTs.
文摘The paper analyzed the recycle condition and developing trend of used refractories China and other countries, irwluding research achievements of recycles of used refractories such as MgO-C bricks, Al2O3-MgO-C brics, Al2O3-SiC-C castable and MgO-Cr2O3 bricks. Recycled refractories exhibit the same or even better properties as compared with the original. In addition, prospects for recycle of used refractories are also discusseded.
基金supported by the Natural Science Foundation of China under Grant No.51502214
文摘Regarding the morphology of alumina,effect of the heredity of raw materials on properties of aluminamagnesia refractory castables was investigated by adding platelet alumina as the specific template.In-situ spinel platelet formed derived from platelet alumina.By comparing phase evolution,apparent porosity,bulk density,permanent linear expansion and strength,it was demonstrated that the utilization of the microstructures＇ heredity of platelet alumina was a new alternative for controlling properties of alumina-magnesia refractory castables.
基金financially supported by the Preliminary Research Project for National Basic Research Program of China (No. 2012CB724607)the Research Planning Project of Basic and Advanced Technology of Henan Province, China (No.162300410043)
文摘The corrosion behavior of alumina-chromia refractory against two kinds of industrial slags （coal slag and iron smelting slag） at 1550℃ was investigated via thermodynamic simulations. In the proposed simulation model, the initial slag first attacks the matrix and surface aggregates and subsequently attacks the inner aggregates. The simulation results indicate that the slag chemistry strongly affects the phase formation and corrosion behavior of the refractory brick. Greater amounts of alumina were dissolved and spinel solid phases formed when the brick interacted with iron smelting slag. These phenomena, as well as the calculated lower viscosity, may lead to much deeper penetration than that exhibited by coal slag and to more severe corrosion compared to that induced by coal slag. The thermodynamic calculations well match the experimental observations, demonstrating the efficiency of the proposed simulation model for evaluating the corrosion behavior of alumina-chromia refractory.
文摘MgO·Al 2O 3 spinel fibers may be obtained by thermal treatment of pressed specimens composed of Mg-Al-O materials with appropriate oxide-metal ratio at high temperature under controlled atmosphere. Their phase composition and microstructure have been examined.
