Abstract: The total cyanide content of the full-slime cyanide tailings slurry of a gold company was 805.58 mg/L，mainly in the form of (ferric) ferricyanide complex ions. The toxicity leaching test was carried out when the raw ore pulp was thickened to concentration of 55%，and the total cyanide content of the leaching solution was as high as 51.7 mg/L. In order to achieve harmless treatment，a series of experiments were carried out. The results showed that it is difficult to effectively remove complex cyanide by a single cyanide breaking process，and the combined cyanide breaking and precipitation cyanide process can effectively remove complex cyanide，but it is difficult to achieve the target requirements. Adding 3 g/L of cyanide breaking agent CG105-A and 2.5 g/L of cyanide precipitation agent CG105-B to the cyanide tailings slurry can meet the target requirements of cyanide treatment.

Key words: cyanide-containing tailing pulp, cyanide residue, INCO method, hydrogen peroxide method, cyanide breaking, cyanide precipitation