Experimental Study On Preparation Of Ceramic Permeable Brick Based On High-carbon Fly Ash

High-carbon fly ash is the waste left by the power plant after power generation.The discharge of a large amount of high-carbon fly ash has greatly wrecked the resources of our country and caused great damage to the ecological environment of our country.The application of high-carbon fly ash to the preparation of sintered bricks not only improves the performance of the permeable bricks but also greatly relieves the tremendous pressure on the shortage of resources in our country.As a new type of green environmental protection material,ceramic water-permeable brick has some porosity so that it has good water-permeable performance and water-holding property,and can effectively alleviate the problems of"urban desertification"and"heat island Effect"problem.In this paper,the use of high-carbon fly ash high-temperature loss,add the appropriate expansion of perlite,foaming agent,prepared in line with national standards ceramic ecological permeable brick for the preparation of permeable brick provides a new idea,with a certain Environmental and economic value.The main contents and conclusions are as follows:?1?The basic properties of the obtained high-carbon fly ash raw materials for the experimental study,including:chemical composition analysis,XRD mineral composition analysis,thermal gravimetric analysis,particle size distribution sieve analysis,scanning electron microscopy experiments.The results show that the main chemical components of high-carbon fly ash are SiO₂,Al₂O₃,CaO,MgO,K₂O,Fe₂O₃ and other oxides.The main components of crystal minerals are quartz,mullite,feldspar,dolomite and hematite Etc.The particle size of high-carbon fly ash is mainly distributed below 250?m,which is a kind of solid waste with high heating value and contains trace floating beads inside.?2?The results of orthogonal test with 5 factors and 4 levels show that the ratio of material and sintering temperature are the most important factors affecting the water permeability and splitting tensile strength of ceramic water-permeable bricks.Through XRD,SEM and other test methods,the strength of the product was analyzed from the mineral components inside the brick body.The water permeability came from the internal pores.?3?The influence of high fly ash content,sintering temperature,perlite content,perlite particle size,holding time and forming pressure on the performance of ceramic water-permeable bricks were studied by single-factor analysis.The results show that the infiltration of expanded perlite greatly improves the water permeability of the specimen,and the splitting tensile strength of the brick body decreases little.With the increasing of the content of high-carbon fly ash,the splitting tensile strength of brick products continuously decreased,the water permeability coefficient increased continuously,while the water retention capacity continued to increase,but the water permeability coefficient was very low.With the increase of particle size of expanded perlite The permeability coefficient and the water retention of the specimens increased continuously,while the tensile strength of the specimens showed the tendency of first rising and then decreasing.With the increasing sintering temperature,the splitting tensile strength of the brick products continuously increased The percolation coefficient decreased while the water retention decreased.With the increase of the content of expanded perlite,the water permeability coefficient of the specimens increased firstly and then kept stable,and the water retention of the specimens kept increasing.The tensile strength of the splitting tended to decrease firstly and then decreased and then decreased again.With the increasing of the forming pressure of the brick,the splitting tensile strength of the product increased continuously and the water permeability coefficient and water holding capacity decreased continuously.With the increase of the holding time The splitting tensile strength of the products increased gradually,and the permeation coefficient and water retention showed the trend of first rising and then stabilizing and then decreasing gradually.?4?On the basis of single factor analysis,by adding the appropriate amount of pore-forming agent,foaming agent,coordinate and optimize the process parameters.The optimal process was as follows:the content of high-carbon fly ash was 50%,the sintering temperature was 1040?,the size of expanded perlite was 40-60 mesh,the content of expanded perlite was 90%,the forming pressure of brick was 15MPa,The time is60min,limestone content is 15%.At this time,the prepared sintered brick has a splitting tensile strength of 3.25MPa,a water permeable coefficient of 3.05×10^-2cm/s and a water retention of 1.88g/cm³,which meets the standard requirements of a national grade A permeable brick.