In this paper,both oxidation and corrosion resistance of low-carbon magnesia-carbon materials containing 4.0wt% graphite with metallic Al and Mg-Al alloy powders as antioxidants were investigated.Meanwhile,the microst...In this paper,both oxidation and corrosion resistance of low-carbon magnesia-carbon materials containing 4.0wt% graphite with metallic Al and Mg-Al alloy powders as antioxidants were investigated.Meanwhile,the microstructures of samples corroded by slag were observed with optical microscope as well.The test results revealed the properties of oxidation and corrosion resistance of low-carbon magnesia-carbon materials could be improved obviously by adding metal Al powder and Mg-Al alloy powder.The rule of improving oxidation resistance was illegibility when metal Al powder and Mg-Al alloy powder were added together.It was harmful to corrosion resistance by mixed adding metal Al powder and Mg-Al alloy powder into the materials,at the same time,the corrosion resistance would decreased with the increasing of Mg-Al alloy content.The corrosion resistance of samples with 0.5wt% or 3.0wt% Mg-Al alloy was better. The oxidation resistance and corrosion resistance of materials with metal Al or Mg-Al alloy respectively were better than that with mixed metal Al and Mg-Al alloy. As a result, Mg-Al alloy was more suitable for low-carbon composite materials than metal Al as additives.展开更多
Effects of Al- Si addition on hot modulus of rup- ture ~ HMOR） . thermal shock resistance ~ TSR~ . phase composition and mierostructure of low-carbon MgO - C materials were investigated. The results show that： Al an...Effects of Al- Si addition on hot modulus of rup- ture ~ HMOR） . thermal shock resistance ~ TSR~ . phase composition and mierostructure of low-carbon MgO - C materials were investigated. The results show that： Al and Si addition to low-carbon MgO - C materials leads to dramatic increase in MOR at elevated temperatures; it increases from 4 MPa to 11 -21 MPa at 1 200 ℃ and from 2 MPa to 21 -29 MPa at 1 400 ℃. Al and Si addition to low-carbon MgO - C materials also improves TSR： residual strength ratio after thermal shock when △T = 1 200 ℃ is increased,from 44% to 73% - 77%. Al reacts with C and N2 to form, Al4C3 and AlN, Si reacts with C to form SiC. Ultimately. in-situ formed non- oxides increase appreciably with temperature rising and are well interlaced in periclase skeleton structure at 1 300 -1 400 ℃. which is beneficial to thermomechanical properties.展开更多
Sludge as the by-product of wastewater treatment usually accumulates toxic substances that require specific treatment before disposal.With the increase of sludge production,the safe and economic treatment of sludge ha...Sludge as the by-product of wastewater treatment usually accumulates toxic substances that require specific treatment before disposal.With the increase of sludge production,the safe and economic treatment of sludge has become a global issue.Construction filed provides a solution for consuming huge volumes of sludge and sludge ash owing to the similar chemical composition with cementitious materials.This paper critically reviewed the current status of recycling sludge and sludge ash into low-carbon construction materials and highlighted the future perspectives of sludge-derived construction materials.Furthermore,the immobilization mechanisms of heavy metals in sludge-derived construction materials were elaborated to promote the actualization of sustainable management of sludge and sludge ash.展开更多
文摘In this paper,both oxidation and corrosion resistance of low-carbon magnesia-carbon materials containing 4.0wt% graphite with metallic Al and Mg-Al alloy powders as antioxidants were investigated.Meanwhile,the microstructures of samples corroded by slag were observed with optical microscope as well.The test results revealed the properties of oxidation and corrosion resistance of low-carbon magnesia-carbon materials could be improved obviously by adding metal Al powder and Mg-Al alloy powder.The rule of improving oxidation resistance was illegibility when metal Al powder and Mg-Al alloy powder were added together.It was harmful to corrosion resistance by mixed adding metal Al powder and Mg-Al alloy powder into the materials,at the same time,the corrosion resistance would decreased with the increasing of Mg-Al alloy content.The corrosion resistance of samples with 0.5wt% or 3.0wt% Mg-Al alloy was better. The oxidation resistance and corrosion resistance of materials with metal Al or Mg-Al alloy respectively were better than that with mixed metal Al and Mg-Al alloy. As a result, Mg-Al alloy was more suitable for low-carbon composite materials than metal Al as additives.
文摘Effects of Al- Si addition on hot modulus of rup- ture ~ HMOR） . thermal shock resistance ~ TSR~ . phase composition and mierostructure of low-carbon MgO - C materials were investigated. The results show that： Al and Si addition to low-carbon MgO - C materials leads to dramatic increase in MOR at elevated temperatures; it increases from 4 MPa to 11 -21 MPa at 1 200 ℃ and from 2 MPa to 21 -29 MPa at 1 400 ℃. Al and Si addition to low-carbon MgO - C materials also improves TSR： residual strength ratio after thermal shock when △T = 1 200 ℃ is increased,from 44% to 73% - 77%. Al reacts with C and N2 to form, Al4C3 and AlN, Si reacts with C to form SiC. Ultimately. in-situ formed non- oxides increase appreciably with temperature rising and are well interlaced in periclase skeleton structure at 1 300 -1 400 ℃. which is beneficial to thermomechanical properties.
基金support from the National Natural Science Foundation of China(No.52236008)the Zhejiang Provincial Natural Science Foundation of China(LZ23E060004)for this study.
文摘Sludge as the by-product of wastewater treatment usually accumulates toxic substances that require specific treatment before disposal.With the increase of sludge production,the safe and economic treatment of sludge has become a global issue.Construction filed provides a solution for consuming huge volumes of sludge and sludge ash owing to the similar chemical composition with cementitious materials.This paper critically reviewed the current status of recycling sludge and sludge ash into low-carbon construction materials and highlighted the future perspectives of sludge-derived construction materials.Furthermore,the immobilization mechanisms of heavy metals in sludge-derived construction materials were elaborated to promote the actualization of sustainable management of sludge and sludge ash.
