| Human beings are faced with two serious problems about resources conservation and environmental protection in current society.According to statistical data,storage number of mine tailing in China reached 14.6 billion tons by the end of 2014.At present,the porous ceramics as a new type of filter materials,has been widely used in many aspects.It is very important to protect our country's environment from industrial solid waste,when we transform it into industrial products by using the tailing as raw material to prepare porous ceramics.This paper takes iron tailing produced by Beijing Miyun Shouyun Mining Group Company iron ore mining in 2015 as main raw materials,prepared iron tailing porous ceramic by foam-gelcasting process and pressureless sintering.Combined with XRD analysis,SEM microstructure analysis and physical and mechanical properties test,the influence of solid content of slurry,sintering temperature and holding time on the structure and properties of materials were studied.In addition,the dedusting efficiency of dust filtration made by iron tailing porous ceramics was tested,and good experimental results were obtained.The main research results were as follows:(1)Under the sintering condition of holding 3h at 1100?,with the increase of the solid content of slurry in forming process,porous ceramic linear shrinkage and porosity of porous ceramic decreased,while pore size became smaller,volume density and the compressive strength increased,and the pore wall thickening.The porosity and strength of porous ceramics with iron tailings were comprehensively considered,the solid content of the best slurry was 45wt.%.The volume density,apparent porosity and compressive strength of the porous ceramics were 0.42g/cm3,83%,1.45MPa,respectively.(2)The effects of sintering temperature on the structure and properties of porous ceramics were investigated when the temperature range from 1070? to 1120 ? under the condition of solid content of 45wt.%and held 3h.Comprehensive analysis showed that the porous ceramic with iron tailings prepared by holding 3h at 1100? had the best performance.(3)The effects of holding time ranged from 3?11 h on the porous ceramics sintered at 1090? were investigated under the condition of solid content of 45wt.%and sintering temperature at 1090?.Results showed as the holding time increased,the linear shrinkage,volume density and compressive strength of the sintered samples increased with the holding time increased,while the water absorption rate and the apparent porosity decreased.Through the SEM analysis,it was found that with the increase of the holding time,the content of glass phase inside the porous ceramics increased with the extension of the holding time.Comprehensive analysis showed that the porous ceramic samples prepared by holding 7h at 1090? had the best performance,The volume density,apparent porosity and compressive strength were 0.43g/cm3,84%and 1.42MPa,respectively.(4)The thermal shock resistance and the corrosion resistance of the porous ceramics with porosity of 81.8%were tested.It was found that the average number of thermal shock resistance of porous ceramics was 50 times at 900? to room temperature thermal shock test,and the strength loss rate was about 50%after thermal shock for about 30 times.After acid and alkali corrosion 1h,the weight loss rate of porous ceramics was 3.45%and 2.11%,respectively.(5)The two kinds of samples with porosity of 80.8%and 84.9%were tested by dust filter test,the results showed that,the filtration resistance was 174.39Pa and 169.49Pa at lm/min wind speed,respectively,dust filtration efficiency were both up to 99%.The results of this study showed that the preparation technology of porous ceramic materials with fine grained iron tailing was simple,low cost,and suitable for industrial manufacture.The results showed that the materials can meet the requirement of industrial waste gas dust removal,and will have broad application prospects in the field. |
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