GB/T 5686.2-2008 specifies three methods for the determination of silicon content in ferromanganese and other materials. Molybdenum blue photometry uses color reaction to determine silicon content by Absorbance; potassium fluorosilicate Titrimetric method is based on titration reaction quantification; perchloric acid weight method determines silicon content by settling and weighing. This standard applies to ferromanganese, manganese silicon alloy and other products. Clarify the required instruments, such as spectrophotometer, Burette, etc., and specify the preparation of reagents. Detail the steps of Sample Handling, including dissolve, separation of interfering elements, etc. Standardize the operation procedures of the three methods. According to this standard, the silicon content can be accurately determined, providing key data for product mass control and iron and steel smelting.