PURPOSE: To improve the gold recovering rate by dissolving gold in ore in an aqueous cyanide soln., allowing the gold to be adsorbed on activated carbon by countercurrent multistage contact while reducing the concn. of cyanogen in the latter half of the contact stages, and recovering the gold.
CONSTITUTION: Gold ore is finely pulverized in an aqueous soln. of sodium cyanide while blowing air, and gold is extracted from the ore and dissolved in the soln. The resulting slurry is passed through many adsorption vessels connected in series, and granular activated carbon is fed from the opposite sides of the vessels and brought into countercurrent contact with the slurry. The gold is allowed to be adsorbed on the activated carbon and recovered. The remaining slurry is discharged after removing cyanogen. By adding an oxidizing agent such as sodium hypochlorite to the slurry in the latter half of the contact stages, free cyanogen is decomposed to reduce the concn., so the power of the activated carbon to adsorb gold is improved, and the gold recovering rate is improved as a whole.
| WO/1999/045158 | GOLD RECOVERY PROCESS |
| WO/2010/121329 | ENHANCED RECOVERY OF GOLD |
| WO/1987/001733 | PROCESS FOR EXTRACTING PRECIOUS METALS FROM ORE CONCENTRATES |
YAMASHITA HIROSHI
TANAKA KATSUHIKO
| JPS5518501A | 1980-02-08 |
Next Patent: SMELTING METHOD IN FLASH SMELTING FURNACE USING COKE BREEZE