METHOD FOR ADDING RAW MATERIAL SLURRY AND SULFURIC ACID TO AUTOCLAVE IN HIGH-PRESSURE ACID LEACHING PROCESS AND AUTOCLAVE

摘要

PROBLEM TO BE SOLVED: To promote mixing of raw material slurry and sulfuric acid in a high-pressure acid leaching process and thereby reduce the control value of the concentration of free sulfuric acid after discharge.SOLUTION: In an autoclave 100 for a high-pressure acid leaching process, raw material slurry and sulfuric acid heated and pressurized are agitated by agitators 30A and others provided in a plurality of respective compartments 20A and others demarcated by partition walls 10A and others in the autoclave to promote leaching, and the slurry is transferred from an upstream compartment to a downstream compartment for leaching. In the autoclave 100, slurry supply pipes 41 and 42 with raw material slurry discharge ports 41A and 42A and sulfuric acid supply pipes 51 and 52 with sulfuric acid discharge ports 51A and 52A are alternately arranged around an impeller 31A of the agitator 30A provided in the upstream end compartment 20A. From the raw material slurry discharge ports 41A and 42A and the sulfuric acid discharge ports 51A and 52A which are located at positions higher than the uppermost part of the impeller 31A and lower than the content liquid level L, the raw material slurry of nickel oxide ore and sulfuric acid are added to the upstream end compartment.