Study On The Thermal Insulation Composite By Iron Tailings/Fly Ash/EPS/Aerogel

Foam insulation material belongs to inorganic porous green energy-saving building materials.As the insulation layer of building exterior wall,it can not only play a good role in thermal insulation,but also has wide source of raw materials,low price and environmental protection.Although foam insulation materials have many advantages as building external wall insulation materials,a large amount of cement needs to be added in production,resulting in economic and environmental pressure.In this dissertation,aiming at the problem of low solid waste content in foam insulation materials,iron tailing and fly ash were used as the main raw material.Portland cement is used as cementitious material.The foamed insulation material with low-density and low thermal conductivity was prepared by adding expanded polystyrene?EPS?particles and SiO₂ aerogel using physical foaming method.The main works were as follows.Based on analyzing the mineral composition of iron tailing and fly ash,a iron tailing/fly ash foamed inorganic insulation material was prepared by controlling the single factor variable method.The results showed that the dry density of iron tailings/fly ash inorganic insulation materials was 243.1 kg/m³,the thermal conductivity was0.083 W/?m?K?and the compressive strength is 0.39 MPa when the ratio of iron tailings was 20 wt%,fly ash was 25 wt%,slag powder was 10 wt%and cement was 45 wt%.Iron tailings/fly ash/EPS composite thermal insulation material was prepared with EPS particles as fillers.It is found that the thermal conductivity of insulation material is the lowest when the EPS particle content is 1.6 wt%.Under the optimum technological conditions,the dry density,compressive strength and thermal conductivity of the iron tailings/fly ash/EPS composite insulation material are 198.7kg/m³,0.26MPa and 0.063 W/?m?K?.In order to further reduce the thermal conductivity of iron tailings/fly ash foamed insulation materials,SiO₂ aerogel as filler was used to prepare iron tailings/fly ash/EPS/SiO₂ aerogel composite thermal insulation material.The results show that when the SiO₂ aerogel content is 0.3 wt%,the bulk density of the iron tailings/fly ash/EPS/SiO₂ aerogel composite insulation material is 205.2 kg/m³,the compressive strength is 0.25 MPa,and the thermal conductivity is 0.057 W/?m?K?.The results of a pilot test showed that the bulk density was 324.1 kg/m³ and the compressive strength is0.49MPa.The thermal conductivity was 0.085 W/?m?K?.