| Co-processing in the cement kiln of municipal waste is more environmentally and energy-saving than traditional waste treatment methods such as incineration,landfill and so on.However,due to complex composition of municipal waste,harmful gases such as sulfur dioxide,hydrogen chloride,potassium sulfate,dioxins and so on will be produced during the calcination process in the cement kiln.The refractory material will be eroded by the gases and cement clinker,which leads to the accelerated erosion rate of the refractory lining in the cement kiln and reduces the service life of the refractory material.Therefore,it is necessary to develop a refractory material with excellent erosion-resistance.It has been reported that the raw material of zinc aluminate spinel has excellent corrosion resistance.Therefore,this paper mainly studies the effect of Ti O2 on the synthesis of zinc aluminate spinel.The alkali salt erosion resistance of zinc aluminate spinel is compared with that of magnesia aluminate spinel spinel and iron aluminum spinel.Periclase-zinc aluminate spinel brick was prepared with high-purity magnesia and zinc aluminate spinel after mixing.The performance is compared with periclase-iron alumina spinel brick used in the clinkering zone of cement kiln.Mineral composition and microstructure of samples are studied by XRD,SEM and so on.The conclusions are as follows:（1）When zinc aluminate spinel is synthesized,Ti O2promotes the synthesis and densification of zinc aluminate spinel by solid solution.When the amount of Ti O2 is more than 1.5%,in addition to the solid solution,the excess Ti O2 will react with Al2O3 to form Al2Ti O5,which is not conducive to the synthesis of zinc aluminate spinel.When the amount of Ti O2 is 1.5%,the performance of the synthesized zinc aluminate spinel is the best.（2）Zinc aluminate spinel has larger interatomic binding force,high density and low coefficient of linear expansion.The liquid phase corrosion of spinel by alkali salt through the gap and gas phase erosion caused by gaseous alkali salt deposition crystallization with volume expansion and loose structure are decreased.The zinc aluminate spinel has the best resistance to alkali salt erosion,iron aluminum spinel comes second,magnesium aluminate spinel is worst.（3）Zinc aluminate spinel is added into periclase-zinc aluminate spinel brick in the form of particles.With the increase of particle addition,the apparent porosity of the sample increases,and the bulk density,normal temperature bending strength and compressive strength decrease.The erosion resistance of cement clinker and alkali salt is reduced,but the thermal shock stability is improved,and the best introduction amount is 10%.（4）Zinc aluminate spinel is added into periclase-zinc aluminate spinel brick in the form of powders.With the increase of powders addition,the apparent porosity,normal temperature bending strength and compressive strength of the samples decreased,the bulk density increased,and the corrosion resistance of cement clinker and alkali salt decreased.The best introduction amount is 5%.（5）The zinc aluminate spinel has no volatilization and valence reaction of elements at the erosion temperature,which will not cause the overall structure of the sample to be loose and not resistant to erosion.At the same time,the overall structure zinc aluminate spinel brick is more compact,blocking the erosion channel of cement clinker and alkali salt into the sample along the pores of the sample,inhibiting the deposition and crystallization of alkali salt in the non-working surface,and the volume expansion produces thermal brittleness and chemical erosion.Therefore,the zinc aluminate spinel has better resistance to alkali salt erosion than the iron-aluminum spinel.Considering the addition of 5%zinc aluminate spinel（containing 1%Ti O2）fine powder sample has the best performance. |
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