Recovery of Valuable Metals from the Leaching Tailings from the Arsenic/Nickel/Cobalt Residue

The leaching residue after extracting arsenic from the arsenic/nickel/cobalt residue is treated to recover copper, cobalt, nickel, and other valuable metals. The experimental results show that the best conditions are as follows: the liquid–solid ratio is 10:1, the ratio of oxidant to raw material is 0.6 ml/g, the sulfuric acid concentration is 20%, the temperature is 40 °C, and the leaching time is 2 h. Under the above conditions, the leaching ratio of copper, cobalt, nickel, zinc, and arsenic reached 96.31%, 97.23%, 98.56%, 98.46%, and 93.84%, respectively. The leaching kinetics of copper, cobalt, and nickel were further studied. The activation energy of copper, cobalt, nickel is 47.22 kJ/mol, 37.91 kJ/mol, and 44.93 kJ/mol, respectively, and the reaction grades are 1.88, 1.94, and 1.92, respectively. The above valuable metals may be further recovered in the leaching residue. This technique is beneficial for the efficient use of resources, reducing resource waste in the metallurgical process.