The reason:

(1) containing cyanide and hydroxide;

(2) have impurities or additives in the solution;

(3) carbonate accumulating too much;

(4) the solution of photoelectric liquid used for a long time.

Processing method:

1) supplement cyanide and hydroxide;

(2) add additives;

(3) adding barium cyanide or reduce the carbonate crystallization temperature, and then filtered to remove electrolyte;

(4) as the solution of photoelectric liquid used for a long time, is recommended to replace the solution of photoelectric liquid.