Study On Preparation Of Self-insulation Materials From Ceramic Waste Residue

This review focuses on the ceramic waste recycling,the latest progress and existing problems of autoclaved aerated concrete thermal insulation w all materials.The research emphasis and development trend were proposed.On the base of series of experiments and analysis,the polishing ceramic powder properties were studied.With the goal of B05 grade aerated concrete,the proportion of materials was designed accord to the physical and chemical properties of the ceramic waste residue.Factors influencing the casting stability and pore structure,such as W/S,additives,mixing time and pouring temperature,were discussed.It focuses on the superfine powder plasma gas and pouring molding method.On this basis,the influences of C/S,the amount of gas agent and cement,and autoclaved conditions on product performance were further researched.It was shown that particle size of polishing powder ceramic was small(D₅₀=11.96?m),the content of SiO₂ and Al₂O₃ are more than 80%,the crystalline phase is quartz and mullite,and it contains 54.9%glassy substance.Besides,it has potential hydraulic ability and pozzolanic ability.Its active index of compressive strength at 3 days is up to 93.2%and 28d 115%.So it can be used as siliceous raw material for the preparation of autoclaved aerated concrete.Because of ceramic tile polishing powder with small particle sizes,the slurry thickens rapidly and the viscosity of the slurry is big,which lead to the difficulty in drilling hole and gas.Aluminum concentration of gas velocity and slurry thickening speed were adjusted by using the self-developed JF-1 type additives.The problem of gas was overcome.W/S,the mixing time and pouring temperature have an important effect on casting stability and pore structure.Above all,when W/S was 0.6⁰.65,slurry liquidity is appropriate and it can form good pore structure body;To reduce W/S,slurry is too thick to pouring;If increasing the W/S,the slurry is too thin to boiling even collapse mode.C/S exercises a great influence on phase formation and crystalline state of tobermorite,and then affects performance of product.When C/S is 0.41⁰.61,it can form quartz and tobermorite.But when C/S is 0.55,the number of hydration products is much and the crystallinity is good,and then the compressive strength is high.C/S is too little,the number of h ydration products is not enough;if too large,the crystallinity is poor.Those can lead to decrease the strength of the sample.The amount of cement affects compressive strength.When adding 8%cement,the compressive strength of sample is 6.07MPa.If the cement is not enough,the body hardens slowly;If the amount is too large,although the body hardens quickly,but due to the excess CaO,it is easy to form the high alkali hydrates,which lead to reduce compressive strength of sample.The product performance is intimately linked with constant pressure and time.The sample,which has a higher strength,was prepared at 1.2MPa for 6h.When the pressure is lower than 0.88 MPa,it does not meet the formation of tobermorite's temperature.If pressure is too high,the xonotlite phase is easy to generate.Hydration reaction is insufficient when holding time is short;But to extend excessively the time,crystallinity of hydration products become poor.Those can make the sample strength reduction.The green body was prepared by the C/S of 0.55,W/S of 0.6,the cement dosage of 4%and Al 0.12%,the mixing time of 40s and slurry pouring temperature of 36?,according to pulping,blank casting and curing.It has good pore structure and uniform pore sizes.The pores are round and obturator rate is high.Then,the sample with dry density of 496kg/m³,compressive strength of6.01MPa and the thermal conductivity of 0.088W/?m?K?was prepared at 1.2MPa for 6h.The quality loss is 1.91%and the loss of compressive strength is 11.3%after 17 cycles of freeze-thaw.All of the properties are far higher than the GB11968-2006 standard.