The invention relates to a method for circularly removing
chlorine in a
zinc sulphate solution by
copper slag. The method comprises the following steps:
copper ions,
zinc powders and a
zinc sulphate solution are added into a
continuous reaction groove and react in a stirring state to obtain the zinc sulphate solution containing Cl<-> equal to or less than0.3g / l, and a CuCl precipitate generated in the reaction enters
slag; a mixture of the zinc sulphate solution and the
slag are treated by liquid-
solid separation to obtain a dechlorinated zinc sulphate solution and
copper slag; the separated
copper slag is washed with alkali to remove
chlorine ions; the
copper slag after being washed with the alkali is returned to the
continuous reaction groove for carrying out a circular reaction; and when the copper ions are deficient, a certain
copper sulfate is added at
proper time for replenishment. The invention utilizes the zinc powders as a
reducer for reacting with the copper ions in the zinc sulphate solution to generate a CuCl
copper slag precipitate, Cl<-> is eluted with the alkali, Cu2O is also obtained and is returned to react with the Cl<-> in the solution for circular dechlorination,
copper sulfate does not need to be added or a little
copper sulfate is only added in the dechlorination process, the consumption of raw materials is little, and the cost is low; compared with a method that the copper slag which can be changed is added continuously, the interference of external factors to a dechlorination technique is little, the process is easy to control, and the dechlorination effect is stable and reliable.