The invention relates to a method for measuring
chlorine ion in a
copper-containing
zinc electrolyte sample, which comprises the steps as follows: taking 20-50 mL of a
zinc electrolyte sample, adding 5mL of 50%
sulfuric acid, adding 0.5-1.0 g of
zinc powder with purity of 99.999% or 0.2-0.5 g of aluminum
powder with purity of 99.999%, stirring until reaction is finished, and diluting to 100 mL with a
volumetric flask; carrying out dry filtering, adding 20-50 mL of filtrate to a 300 mL
beaker, adding 5-6 mL of
nitric acid, adding known amount of excessive
silver nitrate (0.05 mol / L) until
chlorine ion is precipitated completely, heating for boiling to precipitate and flocculate
silver chloride, filtering, washing precipitate, adjusting the volume to 80-100 mL, adding 1 mL of saturated
ferric sulfate solution acidified with
nitric acid, titrating with 0.01 mol / L
potassium thiocyanate solution until the stable red color appears in the solution, namely the end point of
titration. According to the invention, the measuring method can be used for rapidly and accurately measuring
chlorine ion content in the zinc
electrolysis electrolyte without use of an instrument; and high-purity zinc
powder or aluminum powder are adopted to remove interference
metal ions, and the use amount of the reagents and the operation steps are strictly controlled, therefore, the method can be used for accurately measuring in situ and medium and small-sized laboratories.