Efects Of Diferent Additives On Properties Of Inorganic Ceramic Membrane Support Based On Loess

In this paper,tubular ceramic membrane support with loess as aggregate was prepared by rolling molding method.The effects of different particle sizes of pure loess raw materials on the properties of the support were studied;Designed orthogonal experiment by selecting three factors,such as?-Al₂O₃,MgO and CMC;Discussed the effect of bolus alba and bentonite on the properties of support;The properties of the support were characterized by TG-DTG,SEM,XRD and self-made device.The results showed that:?1?The support was prepared by pure loess that filtered with 80,200 and 300 mesh screen clothas.It was found that with the increase of the median particle size of the raw material of pure loess,the flexural strength of the support showed a decreasing trend,and the pure water flux showed an increasing trend;The smaller the particle size,the better the corrosion resistance and stability of the support;When the sinter temperature was 1115?the particle size of the loess was filtered with 200 mesh,the support of flexural strength was 39.47 MPa and the pure water flux was 2009 L/?m²·h·bar?.?2?The pore size distribution showed that the median pore diameter of the support was 4231nm,the average pore size was 1699.1 nm,the porosity was 17.5659%,the pore size was 2448.6 nm³805.3 nm,and the pore volume of main peak was more than 90%of the total pore volume after filtered by 38.78?m diameter screen mesh loess.which indicated that the loess can be used as the raw material for the support.?3?The sintering temperature of orthogonal experiment was carried on three stages:the samples was calcined from room temperature to 200?with the heating rate of 3?/min,then kept for 1 h at 200?;200?-700?,heating rate by 0.5?/min and holding 2 h;the rise rate was 1?/min from 800?to 1180?,then cooled to room temperature with furnace after 3 h.According to the orthogonal experiment,the factors influencing the pure water flux of the support were CMC>Al₂O₃>MgO,and the factors affecting the flexural strength of the support were Al₂O₃>CMC>MgO.After comprehensive analysis,the best combination was that the addition amount of Al₂O₃ was 15%,CMC was 6%,MgO was0.5%.?4?According to orthogonal experiment,the best combination had the performance below:the mechanical strength of 55.66MPa,the pure water flux of 83629.27 L/?m²·h·bar?,the median diameter of 19880.3nm,the peak pore volume accounted for more than 95%of the total pore volume,the the pore size of 8544.6 nm-52230.5749 nm,porosity of 28.7%,principal crystalline phase were quartz,anorthite,mullite,iolite,cristobalite.?5?Finally,the addition amount of bentonite was 6%and sintering temperature was1120?.The support had the performance below:flexural strength of 45.7 MPa,the pure water flux of 1087 L/?m²·h·bar?,the median pore diameter of 2469.71 nm,the main peak pore size distribution range of 374.6 nm-4617.7 nm,and the porosity of 15.60%.The main crystal phase was cristobalite and mullite.?6?When the addition amount of bolus alba was 4%and sintering temperature was1120?,the support had the performance below:flexural strength of 67 MPa,the pure water flux of 1465 L/?m²·h·bar?,the median pore diameter of 3568.4 nm,the main peak pore size distribution range of 1416.59 nm-5532.03 nm,and the porosity of 16.6746%.The main crystal phase was quartz and mullite.