| The paper mainly aims to the asynchronism development status of refractories for continuous casting and continuous casting technology. Through sol-gel process, nano- zirconia precusor sol has been prepared and used to treat surface of sizing nozzle, gaining favorable results.A method using inorganic salt (zirconia chloride octahydrate) as raw material in conjunction with the process of nano-zirconia prepared by sol-gel, technical factors affecting the preparation of nano-zirconia precusor sol have been studied. Adopting supercritical fulid drying technology, nano-zirconia precusor sol has been characterized by XRD and TEM etc. Results show that the size of sol uniformly distributed is less than lOnm. Mechanism of the formation of nano-zirconia precusor sol has been further investigated in the present of paper.Effect of different stabilized agents on the stabilization of nano-zirconia has been systematically researched. It is resulted that stabilized agents and zirconia can be soluted in each other. Beside, order of the ability of stabilizing nano- zirconia after sintered at high temperature is: Y2O3>CaO>MgO.Applying nano-zirconia sol, sizing nozzles have been treated by physical and chemical method respectively and the influence of vary factors on properties of sizing nozzles has been also compared and discussed. It is shown that chemical method is inferior to physical method. Treated by physical method, the total pore volume and pore area of the surface of sizing nozzle would be decreased apparently and the size of pore would be changed from large to small with the apparent porosity of 11% from 20%.
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