Preparation And Properties Of Foam Glass And Its Composite Material By Low Temperature Sintering

This paper used glass powder of low melting point as main raw material and basic magnesium carbonate as foaming agent.Foam glass was prepared by sintering technique of low temperature of about 500℃ at first. Material was detected by X-ray fluorescence spectrometer, X-ray diffraction, simultaneous thermal analysis, thermal dilatometer, thermal conductivity tester, electronic universal testing machine and other equipment.Study the sintering temperature, holding time and content of foaming agent on the influence of structure and properties of foam glass and determine the optimal technological parameters of foam glass.As conent of foaming agent is 2wt%,the sintering temperature is 510℃ and holding time is 50 min,the average pore size of foam glass is 2.05 mm,bulk density is 0.34g/cm3,porosity is 76.63%,the compressive strength is 3.14 MPa and thermal conductivity is 0.064W/(m·k).The higher the sintering temperature is, the less viscosity of glass batch is,the more pressure of gas by reacting of foaming agent is,the more inflationary bubbles are,the thinner wall of hole is,the larger aperture and porosity are and the less bulk density is. The sintering temperature should not be too high,otherwise the sample can not support great pressure and thermal conductivity is large,thus leading to poor of performance of machine and thermal insulation.With the increase of holding time,foaming agent has enough time to react and give off gas,thus foaming effect of sample is good.But too long holding time easily leads to increase of large pores and connected pores inside sample,consequently getting sample of very poor comprehensive performance.The increase of content of foaming agent causes the increase of gas that foaming gent reacts and releases,making pore diameter become large.This paper added diatomite to the above glass batch again and produced diatomite/foam glass composite porous adsorbing material by sintering technique of low temperature. Material was detected by X-ray diffraction,scanning electron microscope and other equipment.Discuss the sintering temperature, holding time and content of diatomite on the influence of structure and properties of composite material and confirm the optimal technological parameters.When conent of diatomite is 30wt%,the sintering temperature is 540℃ and holding time is 70 min,the average pore size of composite material is 2.11 mm,bulk density is 0.46g/cm3 and porosity is 78.39%.With the increase of the sintering temperature and holding time,the pore size and porosity of material become large,bulk density becomes small.The higher the content of diatomite is,the smaller aperture of sample is.When the content of diatomite increases to 50wt%,bubbles are not be basically generated,so foaming effect is relatively poor.This paper used diatomite/foam glass composite material to adsorb copper ion in waste water.Density of copper ion in waste water was detected by atomic absorption spectrophotometer.According to the formula,datas of removal rate and adsorption quantity of copper ion were calculated.Study the content of diatomite of composite material,adsorbent temperature,initial PH value of solution and initial density of solution on the influence of adsorbent effect of copper ion.As the content of diatomite is 30wt%, adsorbent temperature is 10℃, initial PH value of solution is 3.34 and initial density of solution is 20mg/L, adsorbent effect of composite material is relatively good and removal rate of copper ion reaches over 86%. Adsorbent temperature has little influence on removal effect of copper ion.With the rise of adsorbent temperature, removal rate is all over 86% and adsorbent effect is good.With the raise of the content of diatomite, removal rate of copper ion increases.When the content of diatomite rises to 50wt%, removal rate of adsorption balance is only 40%,so adsorbent effect is poor.It is mainly because agglomeration and aggregate produced between particles and particles inside sample hinder adsorption of copper ion.By contrast it is fund that the composite material containing proper amount of diatomite has better effect of adsorbing Cu2+ than diatomite.The bigger initial PH value of solution is,the higher removal rate of copper ion is. Removal rate of copper ion closes to 100% under the condition of weak acid. Initial density of solution has remarkable impact on adsorbent effect.The higher initial density of solution is,the lower removal rate is, the higher adsorption quantity is. The second-order kinetic model and Langmuir model are suitable to describe that the composite material adsorbs Cu2+.