Research On Preparation Of Forsterite-vermiculite Composite Material

Energy consumption increase gradually, Energy-saving and reducing energy-wasting become one of the most urgent task with the development economic of our country,. The forsterite-vermiculite composite material(a kind of high performance insulation materials ) was made from forsterite, expanded vermiculite and phosphate at room temperature. The preparation technology of the forsterite-vermiculite composite material was determined. Curing process of binding system was investigated using XRD and microcalorimeter (SETARAM C-80). The effect of amount of binder, the type of magnesia and the MgO/P₂O₅ molar ratio on the binding performance was studied and optimized. The effect of compressive state and additives on the thermal conductivity of specimens was investigated using Philips XL30 TMP SEM and PBD-02 Flat thermal conductivity meter. The thermal expansion of the specimen was tested.The result indicate that:(1) Performance of specimens depend on forming pressure, ratio of forsterite and expansion vermiculite, grading, ageing time and dwell time. Ageing time is harmful to strength of specimens because phosphate and magnesia react quickly. Expansion of specimens after demoulding can be controlled by suitable dwell time.(2) Reaction between phosphate and magnesia is so speedy and generating more Newberyite that in favor of binding at room temperature. The higher reactivity of magnesia, the more rapidly setting rate, in order to obtain better properties sintered magnesia should be chosen. The bigger amount of binder to the benefit of binding strength. The larger MgO/P₂O₅ molar ratio is disadvantageous to binding strength because of the excessive reaction rate.(3) The compressive state of specimens depend on forming pressure, the bigger forming pressure, the more densify, can decrease the thermal conductivity of specimens in the middle and high temperature range, and the plus material that can reflective thermal radiation also have the same action at various temperatures.(4) Shell temperature of ladle can be decreased using the forsterite-vermiculite composite material as insulation lining without reducing the vessel capacity, and the forsterite-vermiculite composite material is safe and reliable.