Comparison of Leaching Rates of Metals in Presence of Different Buffering Agents in Sodium Chloride Media

In the present work, the leaching rates of valuable metals (copper, nickel and cobalt) from sea nodules are studied in presence of different buffering agents in sodium chloride media by electrochemical leaching method. The purpose of
addition of buffering agents to sodium chloride media is to maintain pH of solution so that total metal recovery as well as metal recovery as cathode
deposit can be improved. The influence of various buffering agents and their concentrations on leaching rates of valuable metals are studied by keeping other conditions constant. It has been observed that addition of buffering agents improved the total metal recovery as well as metal recovery as cathode deposits. These recoveries are found to be highest when formic acid is used as a buffering agent. About 100% valuable metals are recovered at optimum conditions and at the end of 4 hours. The comparison of leaching rates of copper, nickel and cobalt of different media is made and difference in leaching rate is explained.