Production Of Autoclaved Bricks With High Dosage Of Ceramic Polished Slag

In light of the rapid development of urbanization,the demand of building sand is also thriving,which not only consumes huge amount of energy,but also severely pollutes the environment.Hence,it's necessary to replace natural resources with industrial solid waste,and it has become a basic national policy.Autoclaved silicate material is one of the major kinds of building materials,which basically consists of siliceous material and calcareous material.Hydrothermal autoclave process transfers them into a silicate artificial stone material which shows great mechanical performance.This research intends to argue that it's viable to replace natural sand with an industrial solid waste—ceramic polished slag and reduce a kind of high ceramic polished slag addictive building autoclaved bricks.In this paper,we conducted macroscopic physical mechanical performance test and analysis material's microscopic nature like hydration product,structure and morphology by XRF,XRD and SEM.Also,we compared process equipment from two different industrial production line,and conducted systematic research about replacing natural sand with polished slag,mix ratio of autoclaved bricks with 80-92%dosage,production of mixture,production of blank,conservation,and performance of product.We managed to obtain high-performance high ceramic polished slag addictive autoclaved stuffed bricks and porous bricks as experimental product(with a intensity about 3.5-15MPa).This research focus on these following problems and patterns:(1)In the research of material processing and production of mixture,we found that polished slag with 64~69% of SiO2 and 16~18% of Al2O3 showsCharacteristics like fine material,larger than surface,fast reaction speed,easy to group when confront with water.By analysis the dispersion,fluidity and mold filling performance of mixture without sand,we propose that the best water content should be controlled around 7.5-12%,related equipment demands were raised too.(2)By conducting comparative test about forming process equipment,we select equipment with function like bidirectional and multiple compaction,automatic exhaust,and applicable to non-sand powder shape and loose material.The equipment can produce solid or porous brick blank with intensity of 1.5-3MPa,denstity of1300~1600kg/m3.(3)We discovered how to produce a certain kind of autoclaved material.With dosage of polished slag as 80% and 92%,the intensity of this autoclaved material can be up to 60 MPa,and its coefficient of softness can be up to 0.9.(4)By analysis and conducting XRF,XRD,SEM test on different polished slag dosage(80%,92%)and different age specimen on a microscopic level,we found that under certain hydrothermal condition,SiO2,Al2O3 in the polished slag react with CaO,and generate hydrated silicate and hydrate aluminate with low alkalinity.It shows stability in structure,and its intensity grows 9%-19% over time,while its coefficient of softness remains unchanged.Conclusion:From the above experiments and analysis,we knew that when proper process,bidirectional compaction equipment and autoclave conservation are ready,polished slag can replace natural sand at a level about 80-100%,and we can obtain a silicate hydration product with dense structure and stable late performance.We can produce a high solid waste utilization rate,good performance building autoclaved bricks.At the same time,we can produce a new,autoclaved,environment-friendly wall material that without natural sand in it but full of polished slag.