GB/T 6609.31 - 2009 is used to determine the flow angle of aluminum oxide. It stipulates the preparation of the sample to ensure that the sample is representative. Detailed description of the instrument and operation method for measuring the flow angle, including the installation and debugging of the instrument, the method of pouring the sample and the determination of the Measurement angle. Through this standard, the flow characteristic data of aluminum oxide particles can be accurately obtained. This is essential for the transportation and storage of aluminum oxide in the production process and the application in the ceramic, refractory and other industries. It helps enterprises to optimize the production process and improve production efficiency.