A method of producing manganese metal or EMD by leaching a source of manganese with a solution comprising sulfuric acid to form a leach solution, adding one or more sulfides generated in a sulfide recycle stage to the leach solution in order to form sulfide precipitates comprising heavy metal sulfides, removing the sulfide precipitates from the leach solution, feeding the leach solution to one or more electrolytic cells, subjecting the purified leach solution to electrolysis so as to deposit manganese metal or EMD, reacting the sulfide precipitates with an acid to generate H.sub.2S, producing one or more sulfides from the H.sub.2S for recycle. Methods of producing manganese metal and a purified manganese sulfate solution are also provided.

A method of producing manganese metal or EMD by leaching a source of manganese with a solution comprising sulfuric acid to form a leach solution, adding one or more sulfides generated in a sulfide recycle stage to the leach solution in order to form sulfide precipitates comprising heavy metal sulfides, removing the sulfide precipitates from the leach solution, feeding the leach solution to one or more electrolytic cells, subjecting the purified leach solution to electrolysis so as to deposit manganese metal or EMD, reacting the sulfide precipitates with an acid to generate H.sub.2S, producing one or more sulfides from the H.sub.2S for recycle. Methods of producing manganese metal and a purified manganese sulfate solution are also provided.

An electrolytic cell and a method of electrochemical oxidation of manganese(II) ions to manganese(III) ions in the electrolytic cell are described. The electrolytic cell comprises (1) an electrolyte solution of manganese(II) ions in a solution of at least one acid; (2) a cathode immersed in the electrolyte solution; and (3) an anode immersed in the electrolyte solution and spaced apart from the cathode. Various anode materials are described including vitreous carbon, reticulated vitreous carbon, woven carbon fibers, lead and lead alloy. Once the electrolyte is oxidized to form a metastable complex of manganese(III) ions, a platable plastic may be contacted with the metastable complex to etch the platable plastic. In addition, a pretreatment step may also be performed on the platable plastic prior to contacting the platable plastic with the metastable complex to condition the plastic surface.

An electrolytic cell and a method of electrochemical oxidation of manganese(II) ions to manganese(III) ions in the electrolytic cell are described. The electrolytic cell comprises (1) an electrolyte solution of manganese(II) ions in a solution of at least one acid; (2) a cathode immersed in the electrolyte solution; and (3) an anode immersed in the electrolyte solution and spaced apart from the cathode. Various anode materials are described including vitreous carbon, reticulated vitreous carbon, woven carbon fibers, lead and lead alloy. Once the electrolyte is oxidized to form a metastable complex of manganese(III) ions, a platable plastic may be contacted with the metastable complex to etch the platable plastic. In addition, a pretreatment step may also be performed on the platable plastic prior to contacting the platable plastic with the metastable complex to condition the plastic surface.

A method of regenerating an etch solution comprising a metastable complex of manganese(III) ions in a strong acid is described in which at least a portion of the manganese(III) ions in the metastable complex have been destabilized, causing them to disproportionate into manganese dioxide and manganese(II) ions. The method includes the steps of i) adding an effective amount of a reducing agent to the solution; ii) allowing the reducing agent to react with the solution to cause manganese dioxide to dissolve; and (iii) applying an electrical current to regenerate manganese(III) ions in the solution.

A method of regenerating an etch solution comprising a metastable complex of manganese(III) ions in a strong acid is described in which at least a portion of the manganese(III) ions in the metastable complex have been destabilized, causing them to disproportionate into manganese dioxide and manganese(II) ions. The method includes the steps of i) adding an effective amount of a reducing agent to the solution; ii) allowing the reducing agent to react with the solution to cause manganese dioxide to dissolve; and (iii) applying an electrical current to regenerate manganese(III) ions in the solution.

The present disclosure relates to an electrolytic manganese dioxide composition comprising two manganese dioxide phases, at least one of the two manganese dioxide phases having at least a portion that exhibits amorphicity. The two manganese dioxide phases may be present in a ratio of between 9:1 and 1:3. The two manganese dioxide crystal phases may be akhtenskite and ramsdellite. The present disclosure further relates to a battery comprising said electrolytic manganese dioxide composition, and methods of manufacturing said electrolytic manganese dioxide composition. The present disclosure further relates to manufacturing an electrode within a cell, the cell for use as a battery, the electrode comprising electrolytic manganese dioxide composition consisting essentially of two manganese dioxide crystal phases.

The present disclosure relates to an electrolytic manganese dioxide composition comprising two manganese dioxide phases, at least one of the two manganese dioxide phases having at least a portion that exhibits amorphicity. The two manganese dioxide phases may be present in a ratio of between 9:1 and 1:3. The two manganese dioxide crystal phases may be akhtenskite and ramsdellite. The present disclosure further relates to a battery comprising said electrolytic manganese dioxide composition, and methods of manufacturing said electrolytic manganese dioxide composition. The present disclosure further relates to manufacturing an electrode within a cell, the cell for use as a battery, the electrode comprising electrolytic manganese dioxide composition consisting essentially of two manganese dioxide crystal phases.

A method of regenerating an etch solution comprising a metastable complex of manganese(III) ions in a strong acid is described in which at least a portion of the manganese(III) ions in the metastable complex have been destabilized, causing them to disproportionate into manganese dioxide and manganese(II) ions. The method includes the steps of i) adding an effective amount of a reducing agent to the solution; ii) allowing the reducing agent to react with the solution to cause manganese dioxide to dissolve; and (iii) applying an electrical current to regenerate manganese(III) ions in the solution.

A method of regenerating an etch solution comprising a metastable complex of manganese(III) ions in a strong acid is described in which at least a portion of the manganese(III) ions in the metastable complex have been destabilized, causing them to disproportionate into manganese dioxide and manganese(II) ions. The method includes the steps of i) adding an effective amount of a reducing agent to the solution; ii) allowing the reducing agent to react with the solution to cause manganese dioxide to dissolve; and (iii) applying an electrical current to regenerate manganese(III) ions in the solution.