Method for dissolving battery powder in hydrochloric acid

A method for dissolving battery powder in hydrochloric acid, in which battery powder containing valuable metals obtained from waste lithium batteries is dissolved in hydrochloric acid, the method comprising:

• a step of supplying the battery powder to hydrochloric acid with a concentration in a range of 50 to 150 g/L at a mass ratio in a range of 250 to 1000% relative to hydrogen chloride in the hydrochloric acid, and stirring to provide a hydrochloric acid suspension of the battery powder;
• and
• a step of adding a predetermined amount of hydrochloric acid to the hydrochloric acid suspension to set a concentration of hydrochloric acid in the hydrochloric acid suspension to a range of 150 to 350 g/L, and then adjusting and stirring the hydrochloric acid suspension such that the battery powder in the hydrochloric acid suspension has a mass ratio of a range of 50 to 200% relative to hydrogen chloride in the hydrochloric acid suspension to provide a hydrochloric acid solution of the battery powder.