The Research On Test Method Of Corrosion Resistance Of Refractories To The Molten Cryolitic Bath

The aluminum electrolytic cell has been developped rapidly these years and the need of qualified refractories used as cathode linings has increased greatly. Because of refractories'contact with the molten cryolitic bath, their corrosion resistance to molten cryolitic bath becomes a very important influence factor for the sevice life of the aluminum electrolytic cell. At present, there is no standard test method in china.It's very urgent to work out an industry standard of testing method for refactories'corrosion resistance to molten cryolitic bath.The stduy established the static crucible test method to evaluate and compare the corrosion resistance. Based on the chinese practical application of refractories in this field,silica-alumina bricks and dry barrier power were used to carry out the experiments in this work.This method regulated the testing conditions such as temperature,keeping time,sample preparation,cryolitic bath ratio, testing atmosphere and result expression. This method is not only simple and practical, but also easy to prepare samples and fit for all kinds of refracroy material. Moreover, a computer software was designed to calculate the corrosion results which was easy to use and calculated results were accurate and reliable.In this study, the influence factors of the corrosion resistance of refractories to molten cryolitic bath at the different bath ratios and testing atmospheres were discussed. The result shows that: 1.With the increase of the bath ratio, the content of the NaF in cryolitic bath increased, which made the refractories be corroded worse and worse. 2.the corrosion resistance of refractories to molten cryolitic bath in reducing atmosphere was better than in the oxiding atmosphere and the samples hardly showed penetration in the reducing atmosphere.The reason for that should be that there produced much more nepheline in the reducing atmosphere which stopped further penetration. 3.At the same cryolitic bath ratio,when the Al2O3 content increased, the corrosion degree to silica-alumina refractroies increased and with the silimar Al2O3 content, the corrosion degree decreased when the pore dimension increased.