Quality of fly ash Preparation of phosphate ceramic foam
|School||Kunming University of Science and Technology|
|Keywords||fly ash phosphate foam ceramics.|
Coal Ash is one kind of industry solid waste sent off by power plants. Presently about 1. 5 trillion tons of Coal Ash is disposed annually in the world. If it isn’ t processed timely and effectively, it will occupy large amount of land and infield, heavily pollute the environment, have a great influence on the climates and damage the balance of ecosystem. So large-scale reclamation of fly ash has been the focus of the world.On the basis of such traditional technology about utilization of fly ash as sinter brick, concrete full of bubble and porous glass etc, by drawing their good qualities and abandoning their weakness, one kind of new technology about fly ash reclamation named foam ceramics of phosphate made from coal ash, was developed.This study was developed through two steps: First, to develop the solid ceramics of phosphate. Such factors as the amount of phosphoric acid and meltable additives and the agglomeration crafts including the highest temperature, the time of heat preservation at the temperature, and the velocity of temperature rising and falling were individually researched. Moreover, the relationship of them was systematically studied. Thus, the optimal craft was gained. Secondly, to develop the foam ceramics of phosphate by appending appropriate kind and amount of foaming agent on the basis of the solid one. By orthonormal experiment the best craft of foam ceramics was gained. Finally, the material was analysed in the view of mechanical property including bending and tension strength, physical property including density, water assimilating percentage, shrinkage percentage and thermal conductivity and microstructure.It was shown that the best parameters was phosphoric acid 5%(volume amount), waste sand 7%, Meltable additive (A) 2%, the temperature 1050*C and the time of preservation Ih. The properties of the final material was the density:0. 902g/cm3, bending-strength:2. IMpa, tension-strength:9. 875Mpa, thermal conductivity 0. 05W/m k.To prepare the foaming ceramics of phosphate made from the coal ash, not only open up a new technological road of fly ash utilizing, but alsothe product could be widely used in the field of metallic, chemical engineering , energy saving engineering and building etc. So it can bring better economic and social benefits.