Abstract: Battery grade metal sulfate solutions can be prepared directly from electrolytically produced metal objects, such as cathode plates, when these are subjected to an aqueous leaching solution comprising at least one acid leaching agent and a liquid oxidizing agent in a continuous process at elevated temperature and with vigorous mixing. A leaching arrangement comprising a leaching column or reaction vessel is also disclosed.

Abstract: A method is provided for separating the impurities zinc, iron, calcium, copper and/or manganese from an aqueous solution that contains cobalt and nickel. The solution is brought into a mixing contact with an extraction solution, which is pre-loaded with cobalt and nickel ions, whereby the cobalt and nickel in the extraction solution are replaced with the impurity metals, and the aqueous solution is cleaned from impurities after this phase. This purified aqueous solution, raffinate, can be used to pre-charge the extraction solution so that a minor part of the raffinate is contacted with a pre-neutralized extraction solution, whereby the cobalt and nickel replace the alkali metal, alkali earth metal or ammonium ion that is used in the pre-neutralization.

Abstract: The invention relates to a method for separating the impurities zinc, iron, calcium, copper and/or manganese from aqueous solutions that contain cobalt and/or nickel. An aqueous solution (1) containing metallic salts is brought into a mixing contact with an extraction solution (2), which is pre-loaded with cobalt and/or nickel ions, whereby the cobalt and/or nickel in the extraction solution are replaced with the impurity metals, and the aqueous solution is cleaned from impurities after this phase. This purified aqueous solution, raffinate (3), can be used to pre-charge the extraction solution with cobalt and/or nickel ions, so that a minor part (5) of the raffinate is contacted with a pre-neutralized extraction solution (6), whereby the cobalt and/or nickel replace the alkali metal, alkali earth metal or ammonium ion that is used in the pre-neutralization.