Method for recovering nickel in chemical nickel-plating ageing liquid

The invention discloses a method for recovering nickel in a chemical nickel-plating ageing liquid, and the method comprises the following steps: (1) adding 1100-1300 parts by weight of the chemical nickel-plating ageing liquid into an electrolytic cell, and regulating the pH value of the ageing liquid to 8-10 by use of solid sodium hydroxide; (2) dissolving 0.01-0.03 part by weight of polyethylene glycol, 0.01-0.02 part by weight of 2-mercapto benzimidazole, 0.03-0.06 part by weight of thiourea, 0.005-0.03 part by weight of hide glue and 0.3-0.5 part by weight of sodium hypophosphite into 40-70 parts by weight of water, adding the mixture into the electrolytic cell, and adding 1-3 parts by weight of 5mol/L hydrochloric acid solution; (3) at normal temperature, on the basis of taking a stainless steel plate as a cathode and a reticular plate plated with iridium oxide titanium alloy as an anode, reacting for 8-10 hours at constant reaction current of 0.6-1.0A, thus obtaining a recoveredmetal nickel on the catho