The Preparation Of Thermal Insulation Materials By Using Obsidian

A large number of organic thermal insulation materials are used in the external walls of buildings,resulting in frequent occurrence of fire accidents.Inorganic thermal insulation materials with excellent thermal insulation properties need to be developed.Both obsidian and perlite belong to acid volcanic rock and have similar structure and chemical composition,but the insulation material prepared from expanded obsidian could not reach the performance level of that prepared from expanded perlite.So far,obsidian cannot be used in large quantities,although its resource is abundant.In order to comprehensively utilize this resource,we developed a new type of lightweight thermal insulation material by using obsidian as a main raw material with an energy-efficient and environmental friendly way in present work.The effects of raw materials such as obsidian/sodium silicate,H2O2 and cetyltrimethylammonium bromide on physical properties including thermal conductivity,pore characters,density and compressive strength were studied in detail.The optimized thermal insulation material exhibits low thermal conductivity(0.051-0.86 W·m^-1·K^-1),low density?0.1-0.24 g/cm³?and adjustable compressive strength?0.09-1.52 MPa?.Compared to other inorganic insulation materials which were reported,this new thermal insulation material is very light,and it has better thermal insulation performance.Therefore,this work proposes a new energy-efficient way to prepare a promising noncombustible thermal insulation material,and also provide a way to use obsidian resource in large quantities.After the preparation of the obsidian porous thermal insulation material,this paper studied the heat transfer mechanism of the porous thermal insulation material,and the theoretical model is optimized to make the calculated results more consistent with the actual thermal conductivity.According to the model,methods to further reduce the thermal conductivity of porous materials is proposed,which provides theory basis for the whole research work.