Since China’s Reform and Opening-up,the innovation and development of refractories for ironmaking industry in Sinosteel Luonai were narrated,including silica materials,Al_(2)O_(3)-SiO_(2) refractories and non-oxide c...Since China’s Reform and Opening-up,the innovation and development of refractories for ironmaking industry in Sinosteel Luonai were narrated,including silica materials,Al_(2)O_(3)-SiO_(2) refractories and non-oxide composites;and the development direction of refractories for ironmaking industry was prospected.展开更多
The importance of basic refractories during the development of steel,non-ferrous and cement industries was introduced.The process of magnesia-chrome bricks was expounded.The development history of basic refractories o...The importance of basic refractories during the development of steel,non-ferrous and cement industries was introduced.The process of magnesia-chrome bricks was expounded.The development history of basic refractories of Sinosteel Luonai as well as the research and application of magnesia-chrome bricks and chrome free bricks for RH vacuum refining furnaces,heavy non-ferrous smelting furnaces,and cement kilns was emphasized.展开更多
To maintain the volume stability of lightweight magnesia-silica castables during heating,lightweight spherical forsterite aggregates(8-5,5-3,3-1 and 1-0 mm),pre-synthesized forsterite fine powder(≤0.074 and≤0.044 mm...To maintain the volume stability of lightweight magnesia-silica castables during heating,lightweight spherical forsterite aggregates(8-5,5-3,3-1 and 1-0 mm),pre-synthesized forsterite fine powder(≤0.074 and≤0.044 mm),natural silica powder(≤0.074 mm),middle grade magnesia fine powder(≤0.074 and≤0.044 mm)and silica fume were used as the raw materials to prepare lightweight magnesia-silica castables,and the magnesia fine powder and natural silica powder were gradually replaced by pre-synthesized forsterite fine powder(10%,20%,30%and 40%,by mass).The properties of the castables were tested and the microstructure was analyzed.The influence of the pre-synthesized forsterite fine powder addition on their properties was researched.The results show that:with the increase of the pre-synthesized forsterite fine powder addition in the matrix,the workability of the castables is almost the same.After being heated at 1450℃for 3 h,the bulk density of the castables increases,the apparent porosity decreases,the permanent linear change changes from expansion to shrinkage,the cold strengths increase firstly and then decrease,and the thermal conductivity at different temperatures increases.Generally,the optimal pre-synthesized forsterite fine powder addition is 20%.展开更多
Dense corundum-mullite brick for blast furnace ceramic pad was prepared using white fused corundum and tabular corundum as aggregates,andalusite fine powder,sillimanite fine powder,zircon sand powder and Guangxi soil ...Dense corundum-mullite brick for blast furnace ceramic pad was prepared using white fused corundum and tabular corundum as aggregates,andalusite fine powder,sillimanite fine powder,zircon sand powder and Guangxi soil as the matrix,and phosphate as the binder,introducing different amounts ofα-alumina micropowder,tabular corundum fine powder and fused corundum powder.The properties of the prepared brick were studied.The results show that,the brick with 10 mass%of tabular corundum fine powder fired at 1560℃for 3 h in a tunnel kiln has the bulk density of 3.08 g·cm^(-3),the apparent porosity of 13.2%,the cold compressive strength of 178 MPa,the molten iron corrosion rate of 0.6%,the slag corrosion rate of 6.4%,the alkali resistance strength decreasing rate of 7.5%,and the thermal shock resistance of 32 cycles,which is both dense and of good thermal shock resistance.The slag resistance simulation test was performed,which proved that the prepared corundum-mullite brick is better than those currently supplied in the market.展开更多
To reveal the damage mechanism of high chrome bricks for opposed multi nozzle gasifier with expanded diameter,the chemical composition and the morphology of a used high chrome brick were researched using XRF,SEM and E...To reveal the damage mechanism of high chrome bricks for opposed multi nozzle gasifier with expanded diameter,the chemical composition and the morphology of a used high chrome brick were researched using XRF,SEM and EDS,and the properties of the high chrome bricks were improved by adding ultra fine alumina,alumina-chrome-iron oxide synthetic material with spinel structure,and chromium metal.The results show that(1)the high chrome brick is seriously damaged by the chemical dissolution of chrome as well as the chemical reactions at the slag/brick interface,the slag penetration and the structural spalling;(2)FeO in the slag reacts with Cr_(2)O_(3)in the brick to form a FeCr_(2)O_(4)layer on the particle surface thus leading to spalling;CaO reacts with SiO_(2)and Al2O3 in the brick forming a metamorphic layer of low melting point materials;due to the different thermal expansion coefficients of the metamorphic layer and the original brick,cracks appear and continue to expand and deepen under multiple temperature and pressure fluctuations thus leading to spalling of brick layer;(3)the improved brick has decreased apparent porosity,increased bulk density and compressive strength,and better thermal shock resistance compared with the original brick;after one cycle of on-site application,the furnace lining surface is smooth and flat with little damage,indicating that the improved high chrome bricks basically meet the working condition requirements of the opposed multi nozzle gasifier with expanded diameter,however,the final effects need to be evaluated in detail after the whole furnace service.展开更多
To reduce production costs and make full and reasonable use of raw materials,high alumina bricks were prepared using tabular corundum and mullite as aggregates,sillimanite as intermediate particles,and white fused cor...To reduce production costs and make full and reasonable use of raw materials,high alumina bricks were prepared using tabular corundum and mullite as aggregates,sillimanite as intermediate particles,and white fused corundum powder,α-alumina micropowder,and Suzhou soil as the matrix,firing at different temperatures(1420,1440,1460,1480,1500 and 1520℃)for 4 h.The apparent porosity(AP),the bulk density(BD),the cold crushing strength(CCS),the thermal shock resistance(TSR),the refractoriness under load(RUL)and the creep rate of the samples were tested.The effects of the firing temperature on the creep rate(1450℃×50 h,under a load of 0.2 MPa)of the samples were studied.The results show that with the sillimanite addition of 22.5 mass%,the sample fired at 1460℃for 4 h performs the best comprehensive properties:the AP of 17.5%,the BD of 2.75 g·cm^(-3),the CCS of 100.5 MPa,the TSR number of 35 cycles,the RUL of 1682℃,and the creep rate of-0.428%,which can prolong the service life of furnaces.展开更多
文摘Since China’s Reform and Opening-up,the innovation and development of refractories for ironmaking industry in Sinosteel Luonai were narrated,including silica materials,Al_(2)O_(3)-SiO_(2) refractories and non-oxide composites;and the development direction of refractories for ironmaking industry was prospected.
文摘The importance of basic refractories during the development of steel,non-ferrous and cement industries was introduced.The process of magnesia-chrome bricks was expounded.The development history of basic refractories of Sinosteel Luonai as well as the research and application of magnesia-chrome bricks and chrome free bricks for RH vacuum refining furnaces,heavy non-ferrous smelting furnaces,and cement kilns was emphasized.
文摘To maintain the volume stability of lightweight magnesia-silica castables during heating,lightweight spherical forsterite aggregates(8-5,5-3,3-1 and 1-0 mm),pre-synthesized forsterite fine powder(≤0.074 and≤0.044 mm),natural silica powder(≤0.074 mm),middle grade magnesia fine powder(≤0.074 and≤0.044 mm)and silica fume were used as the raw materials to prepare lightweight magnesia-silica castables,and the magnesia fine powder and natural silica powder were gradually replaced by pre-synthesized forsterite fine powder(10%,20%,30%and 40%,by mass).The properties of the castables were tested and the microstructure was analyzed.The influence of the pre-synthesized forsterite fine powder addition on their properties was researched.The results show that:with the increase of the pre-synthesized forsterite fine powder addition in the matrix,the workability of the castables is almost the same.After being heated at 1450℃for 3 h,the bulk density of the castables increases,the apparent porosity decreases,the permanent linear change changes from expansion to shrinkage,the cold strengths increase firstly and then decrease,and the thermal conductivity at different temperatures increases.Generally,the optimal pre-synthesized forsterite fine powder addition is 20%.
文摘Dense corundum-mullite brick for blast furnace ceramic pad was prepared using white fused corundum and tabular corundum as aggregates,andalusite fine powder,sillimanite fine powder,zircon sand powder and Guangxi soil as the matrix,and phosphate as the binder,introducing different amounts ofα-alumina micropowder,tabular corundum fine powder and fused corundum powder.The properties of the prepared brick were studied.The results show that,the brick with 10 mass%of tabular corundum fine powder fired at 1560℃for 3 h in a tunnel kiln has the bulk density of 3.08 g·cm^(-3),the apparent porosity of 13.2%,the cold compressive strength of 178 MPa,the molten iron corrosion rate of 0.6%,the slag corrosion rate of 6.4%,the alkali resistance strength decreasing rate of 7.5%,and the thermal shock resistance of 32 cycles,which is both dense and of good thermal shock resistance.The slag resistance simulation test was performed,which proved that the prepared corundum-mullite brick is better than those currently supplied in the market.
文摘To reveal the damage mechanism of high chrome bricks for opposed multi nozzle gasifier with expanded diameter,the chemical composition and the morphology of a used high chrome brick were researched using XRF,SEM and EDS,and the properties of the high chrome bricks were improved by adding ultra fine alumina,alumina-chrome-iron oxide synthetic material with spinel structure,and chromium metal.The results show that(1)the high chrome brick is seriously damaged by the chemical dissolution of chrome as well as the chemical reactions at the slag/brick interface,the slag penetration and the structural spalling;(2)FeO in the slag reacts with Cr_(2)O_(3)in the brick to form a FeCr_(2)O_(4)layer on the particle surface thus leading to spalling;CaO reacts with SiO_(2)and Al2O3 in the brick forming a metamorphic layer of low melting point materials;due to the different thermal expansion coefficients of the metamorphic layer and the original brick,cracks appear and continue to expand and deepen under multiple temperature and pressure fluctuations thus leading to spalling of brick layer;(3)the improved brick has decreased apparent porosity,increased bulk density and compressive strength,and better thermal shock resistance compared with the original brick;after one cycle of on-site application,the furnace lining surface is smooth and flat with little damage,indicating that the improved high chrome bricks basically meet the working condition requirements of the opposed multi nozzle gasifier with expanded diameter,however,the final effects need to be evaluated in detail after the whole furnace service.
文摘To reduce production costs and make full and reasonable use of raw materials,high alumina bricks were prepared using tabular corundum and mullite as aggregates,sillimanite as intermediate particles,and white fused corundum powder,α-alumina micropowder,and Suzhou soil as the matrix,firing at different temperatures(1420,1440,1460,1480,1500 and 1520℃)for 4 h.The apparent porosity(AP),the bulk density(BD),the cold crushing strength(CCS),the thermal shock resistance(TSR),the refractoriness under load(RUL)and the creep rate of the samples were tested.The effects of the firing temperature on the creep rate(1450℃×50 h,under a load of 0.2 MPa)of the samples were studied.The results show that with the sillimanite addition of 22.5 mass%,the sample fired at 1460℃for 4 h performs the best comprehensive properties:the AP of 17.5%,the BD of 2.75 g·cm^(-3),the CCS of 100.5 MPa,the TSR number of 35 cycles,the RUL of 1682℃,and the creep rate of-0.428%,which can prolong the service life of furnaces.
