To solve the problem of over-high density of lightweight insulation refractory bricks prepared with fly ash, new lightweight insulation refractory materials with density 〈 0. 89 g · cm^-3 were .synthesized using...To solve the problem of over-high density of lightweight insulation refractory bricks prepared with fly ash, new lightweight insulation refractory materials with density 〈 0. 89 g · cm^-3 were .synthesized using pyrophyl-lite, .fly ash, and Suzhou clay as the main starting materials and saw dast as the pore forming substance, and controlling the addition of the pyrophyllite （20%, 30% , and 40% by mass ） and the treating temperature （1 250, 1 300, 1 350, and 1 400 ℃ ）. The synthesized materials were characterized by the XRD, SEM and the thermal conductivity measuring in.strument. The results show at pyrophyllite addition of 30% and treat temperature of l 400 ℃ , the material can achieve linear shrinkage of 6. 6%, apparent porosity of 57%, bulk density of 0. 75 g · cm^-3, compressive strength of 2.7 MPa, and thermal conductivity at 350 ℃ of 0. 152 -0. 216 W·（ m·K）^-1.This indicates that the pyrophyllite decomposition at high temperatures forms mullite and amorphous quartz introducing volume expansion, which counteracts some shrinkage at high temperatures. So it is feasible to use pyrophyllite, fly ash waste and clay to prepare lightweight insulation refractory materials.展开更多
Low grade magnesite is one of the main research directions in the future as the raw material for the preparation of magnesia based insulating refractories.Periclase-forsterite(MgO-Mg_(2)SiO_(4)) lightweight insulating...Low grade magnesite is one of the main research directions in the future as the raw material for the preparation of magnesia based insulating refractories.Periclase-forsterite(MgO-Mg_(2)SiO_(4)) lightweight insulating refractories were prepared by the molten salt method with high silica magnesite and tertiary talc ore as raw materials by pretreating them to get light burnt magnesia and talc,and NaCl molten salt as the reaction medium.The effects of the NaCl addition,the sintering temperature,the holding time and the raw material ratio on the sample preparation were studied.The results show that when the NaCl addition is 20% of the mass of light burnt magnesia and talc mixture,the sintering temperature is 1 200 ℃,the holding time is 6 h,and m(light burnt magnesia):m(talc)=5:5,the sample has the optimal comprehensive properties:the bulk density of 1.46 g·cm^(-3) and the apparent porosity of 55.0%.In addition,it is found that self-decomposition of talc and the formation of forsterite can form pores inside the sample.展开更多
Lightweight geomaterial（LWGM）possesses such merit characteristics as low unit weight,environmental protection（recycling these materials instead of stockpiling them）,buffering mechanical property and thermal insula...Lightweight geomaterial（LWGM）possesses such merit characteristics as low unit weight,environmental protection（recycling these materials instead of stockpiling them）,buffering mechanical property and thermal insulation[1].LWGM,an attractive substitute for earth fills,展开更多
基金financial support from the National Nature Science Foundation of China(51502213)
文摘To solve the problem of over-high density of lightweight insulation refractory bricks prepared with fly ash, new lightweight insulation refractory materials with density 〈 0. 89 g · cm^-3 were .synthesized using pyrophyl-lite, .fly ash, and Suzhou clay as the main starting materials and saw dast as the pore forming substance, and controlling the addition of the pyrophyllite （20%, 30% , and 40% by mass ） and the treating temperature （1 250, 1 300, 1 350, and 1 400 ℃ ）. The synthesized materials were characterized by the XRD, SEM and the thermal conductivity measuring in.strument. The results show at pyrophyllite addition of 30% and treat temperature of l 400 ℃ , the material can achieve linear shrinkage of 6. 6%, apparent porosity of 57%, bulk density of 0. 75 g · cm^-3, compressive strength of 2.7 MPa, and thermal conductivity at 350 ℃ of 0. 152 -0. 216 W·（ m·K）^-1.This indicates that the pyrophyllite decomposition at high temperatures forms mullite and amorphous quartz introducing volume expansion, which counteracts some shrinkage at high temperatures. So it is feasible to use pyrophyllite, fly ash waste and clay to prepare lightweight insulation refractory materials.
文摘Low grade magnesite is one of the main research directions in the future as the raw material for the preparation of magnesia based insulating refractories.Periclase-forsterite(MgO-Mg_(2)SiO_(4)) lightweight insulating refractories were prepared by the molten salt method with high silica magnesite and tertiary talc ore as raw materials by pretreating them to get light burnt magnesia and talc,and NaCl molten salt as the reaction medium.The effects of the NaCl addition,the sintering temperature,the holding time and the raw material ratio on the sample preparation were studied.The results show that when the NaCl addition is 20% of the mass of light burnt magnesia and talc mixture,the sintering temperature is 1 200 ℃,the holding time is 6 h,and m(light burnt magnesia):m(talc)=5:5,the sample has the optimal comprehensive properties:the bulk density of 1.46 g·cm^(-3) and the apparent porosity of 55.0%.In addition,it is found that self-decomposition of talc and the formation of forsterite can form pores inside the sample.
文摘Lightweight geomaterial（LWGM）possesses such merit characteristics as low unit weight,environmental protection（recycling these materials instead of stockpiling them）,buffering mechanical property and thermal insulation[1].LWGM,an attractive substitute for earth fills,
