| Green water and green mountains are the golden mountains and silver mountains.The concept of building a beautiful China has become a major stream of social development,and all sectors of society are also developing in the direction of green and environmental protection.However,the total amount of industrial waste discharge in China and various industrial wastes accumulated in the early years has reached a very high level,so it is imperative to make use of these useful wastes as much as possible In the eyebrows.Fly ash and coal gangue are industrial wastes,which contain silica,alumina,calcium oxide and other main components needed for the preparation of light aggregate.Therefore,the reasonable use of these industrial wastes to prepare light aggregate is a way to realize the effective utilization of resources.As artificial lightweight aggregate,lightweight aggregate has many functions,such as light weight,low cost,high durability,high strength,heat preservation,anti-seismic,etc.it was widely used in fillers and biofilter building materials.Lightweight aggregate can meet the requirements of strength and reduce the self weight of structures when it was used in construction projects,which makes lightweight aggregate have very important application value.For the needs of environmental protection and resource conservation,the theory and application technology of preparing high-performance lightweight aggregate from industrial waste has research value and guiding significance.In this experiment,fly ash and coal gangue industrial solid waste are used as the main raw materials,and 0.5~1%expansion aids were added.The formula is based on the real three-phase diagram.The appropriate proportion of raw materials was selected in the suitable foaming range for design test.The sintering temperature range is preliminarily determined by combining DSC and high temperature sintering optical real-time observation system.The controllable sintering furnace was used in the laboratory,and single factor analysis was used The influence of raw material pre sintering,sintering temperature,sintering time and the amount of expansion aid SiC on the properties of the samples was studied.The experimental study on the preparation of high strength industrial waste light aggregate was carried out.The results show that when the calcination temperature is 1240~1280?,and the calcination time is 10~20min,with the increase of the content of gangue(0~30%in a certain range),the bulk density and apparent density of industrial waste lightweight aggregate increase,and the water absorption rate decreases in 1h,but the obvious change is that the particle strength increases,and the internal structure of particles is relatively stable;the fixed raw material ratio is unchanged,and with the sintering temperature increasing When the ratio of fly ash to coal gangue is determined,the volume density,apparent density and 1-hour water absorption of the lightweight aggregate will decrease with the increase of the content of expanding agent.Based on the results of the orthogonal test,the optimal mix proportion(grade 700)of the light aggregate with high strength and light industrial waste residue is obtained.The results show that the lightweight high strength industrial waste light aggregate can be produced by using more than 95%industrial solid waste.The best ratio was:Fly Ash:gangue:expanding aid SiC=90%:10%:1%.The best sintering process is:sintering temperature1265?,sintering time 15 minutes.After testing,the particle strength of the sample can reach 2.05 MPa,the packing density is 612kg/m~3,the grade is 700,the apparent density is1125kg/m~3,the water absorption rate in 1h was 14.8%,the loss on ignition is 4.5%,and all properties meet the basic requirements. |
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