The Preparation Of Periclase-spinel Refractories And The Study For Its Cement Clinker Coating Performance

The raw materials selected for this study are fused magnesia（3-1mm）, high purity sinteredmagnesia（1-0mm；<0.088mm）, sintered spinel, α-Al₂O₃micro powder, amorphism TiO₂powder, monoclinic ZrO₂powder, using sulfite lye as the bonding agent. The raw materials aremixed, attrition milled, compacted under a uniaxial pressure of150MPa and finally fired in thetemperature of1600℃for3hours. This paper reports on the periclase-spinel refractories’sinterability, mechanical properties, high temperature performance and cement clinker coatingproperties as a function of the spinel’s additive amount, particle size and arraymode, and studythe influence of the amorphism TiO₂and monoclinic ZrO₂on the periclase-spinel refractories’properties. The importance results have been obtained as follows.（1） The bigger the spinel’s grain size, the better the erosion-resisting characteristics to thecement clinker of the periclase-spinel refractories, and the bigger the samples’ compressivestrength.When3¹mm spinel added at the amount of9¹2%, the periclase-spinel refractorieshave the best thermal shock performance.The sinterability of the periclase-spinel r refractoriescould be promoted by adding α-Al₂O₃micropowder into it, the sample contained2%α-Al₂O₃had the highest densification and refractoriness under load.（2） Amorphous TiO₂powder can promotes the sinterability of the periclase-spinelrefractories, it can reacts with CaO coming from cement clinker to the high melting point phaseCaTiO₃, which is good for cement clinker coating on the periclase-spinel refractories, and theformation of the high melting point phase can play a certain obstacles to protect the bricks,reducing corrosion of the liquid phase from cement clinker meting.（3） the periclase particles in the periclase-spinel refractories will combine directly whenadded monoclinic ZrO₂powder into it. Monoclinic ZrO₂can reacts with CaO coming fromcement clinker to the high melting point phase CaTiO₃, which is good for cement clinker coatingon the periclase-spinel refractories. The direct bonding structure and the formation of the highmelting point phase in the sample can greatly protect the bricks without being eroded by theliquid phase from cement clinker meting.（4） The combined agent by amorphous TiO₂powder and monoclinic ZrO₂powder canpromotes the sinterability of the periclase-spinel refractories effectively, TiO₂and ZrO₂canreacts with CaO coming from cement clinker to the high melting point phase （CaTiO₃）SSand（CaZrO₃）SS, which is good for cement clinker coating on the periclase-spinel refractories, andcan block the clinker to penetrating into the brick. The optimal composition of the combinedagent is1.2%amorphous TiO₂and1.3².3%monoclinic ZrO₂.