Recovery of nickel from industrial pickling acid solutions

摘要

Nickel is recovered from pickling acid solutions of crude ore using boric acid as catalyst by ultrasound assisted electrolysis.

主权项

1. A method, comprising:
receiving wastewater comprising nickel chloride at a concentration between 0.5 g/l and 5.0 g/l in an electrolysis chamber comprising a carbon cathode and a carbon anode; mixing the wastewater with boric acid to form a solution, wherein a ratio of a concentration of boric acid to a concentration of nickel chloride in the formed solution is 1 to 8 to form a weak nickel borate complex Ni(H2BO3)2; electrolyzing the solution in the electrolysis chamber with the solution at 60° C. and a voltage difference of 3.3 V across the carbon cathode and the carbon anode; applying an ultrasound wave at 40 KHz to the solution for transferring nickel ions from the solution to the carbon cathode; and removing the nickel from the solution, wherein applying the ultrasonic wave comprises reducing a Nerst diffusion layer at a surface of the carbon cathode by the ultrasonic wave.