Methods for extracting a target metal from a mixed metal input are described. The method includes milling the mixed metal input with ammonium bicarbonate to form a milled solid product, aging the milled solid product, and leaching the target metal from the aged solid product.

Systems and methods for sequestering carbon, evolving hydrogen gas, producing iron oxide as magnetite, and producing magnesium carbonate as magnesite through sequential carbonation and serpentinization/hydration reactions involving processed olivine- and/or pyroxene-rich ores, as typically found in mafic and ultramafic igneous rock. Precious or scarce metals, such nickel, cobalt, chromium, rare earth elements, and others, may be concentrated in the remaining ore to facilitate their recovery from any gangue material.

The present disclosure is directed to a process for recovering copper and cobalt from a copper and cobalt-containing sulfide ores and concentrates, particularly relatively low grade cobalt bearing sulfide ores and concentrates.

What is provided is a method for separating cobalt and nickel including: a crushing and sorting step of crushing and classifying the lithium ion secondary battery to obtain an electrode material containing at least cobalt, nickel, copper, and lithium; a leaching step of immersing the electrode material in a processing liquid containing sulfuric acid and hydrogen peroxide to obtain a leachate; a copper separation step of adding a hydrogen sulfide compound to the leachate with stirring and subsequently carrying out solid-liquid separation to obtain an eluate containing cobalt and nickel and a residue containing copper sulfide; and a cobalt/nickel separation step of adding an alkali metal hydroxide to the eluate to adjust a pH and subsequently, adding a hydrogen sulfide compound with stirring and carrying out solid-liquid separation to obtain a precipitate containing cobalt sulfide and nickel sulfide and a residual liquid containing lithium.