Methods are proposed for extracting transition metal oxides from scrap batteries by dissolving the metal oxides in a glass-forming oxide melt, followed by electrolytic reduction of the transition metal onto the cathode of an electrolytic cell. Suitable glass-forming oxide melts include borate and pyrophosphate melts with added Na.sub.2O or NaF. The method is particularly suited to the recovery of cobalt, nickel, and manganese from scrap battery and electronic materials. A preferred recycling process includes first recovering lithium metal from scrap battery material, and then extracting transition metal oxides from the lithium-depleted material.

Methods are proposed for extracting transition metal oxides from scrap batteries by dissolving the metal oxides in a glass-forming oxide melt, followed by electrolytic reduction of the transition metal onto the cathode of an electrolytic cell. Suitable glass-forming oxide melts include borate and pyrophosphate melts with added Na.sub.2O or NaF. The method is particularly suited to the recovery of cobalt, nickel, and manganese from scrap battery and electronic materials. A preferred recycling process includes first recovering lithium metal from scrap battery material, and then extracting transition metal oxides from the lithium-depleted material.

An object of the present invention is to provide a Mn-based alloy exhibiting metamagnetism over a wide temperature range. A MnAl alloy according to the present invention exhibits metamagnetism and has crystal grains containing a τ-MnAl phase and crystal grains containing a γ2-MnAl phase. Assuming that the area of the crystal grains containing the τ-MnAl phase in a predetermined cross section is B, and the area of the crystal grains containing the γ2-MnAl phase therein is A, the value of B/A is 0.2 or more and 21.0 or less. When the ratio of the areas between the crystal grains containing the τ-MnAl phase and those containing the γ2-MnAl phase is controlled within the above range, metamagnetism is imparted to the MnAl alloy and, thus, it is possible to obtain metamagnetism over a wide temperature range, particularly, over a temperature range of −100° C. to 200° C.

An object of the present invention is to provide a Mn-based alloy exhibiting metamagnetism over a wide temperature range. A MnAl alloy according to the present invention exhibits metamagnetism and has crystal grains containing a τ-MnAl phase and crystal grains containing a γ2-MnAl phase. Assuming that the area of the crystal grains containing the τ-MnAl phase in a predetermined cross section is B, and the area of the crystal grains containing the γ2-MnAl phase therein is A, the value of B/A is 0.2 or more and 21.0 or less. When the ratio of the areas between the crystal grains containing the τ-MnAl phase and those containing the γ2-MnAl phase is controlled within the above range, metamagnetism is imparted to the MnAl alloy and, thus, it is possible to obtain metamagnetism over a wide temperature range, particularly, over a temperature range of −100° C. to 200° C.

Disclosed are anodes for an electrochemical reduction system, such as for the electrochemical reduction of oxides in systems using molten salt electrolytes. The anodes comprise a rod or plate formed of and include at least one alloy of at least one transition metal and at least one platinum group metal. The alloy anodes may be less expensive than anodes formed solely from platinum group metals and may exhibit less material attrition than anodes formed solely from transition metals. Related methods and electrochemical reduction systems are also disclosed.

A method for separating metal components from a treatment material containing a silicate and metal elements includes: a reaction step of reacting the treatment material and a molten alkali hydroxide in which bubbles due to water vapor derived from water are generated by heating a hydroxide of an alkali metal or an alkaline-earth metal and the water in a state where the hydroxide and the water coexist, to obtain a reaction product; and a first precipitation step of dissolving the reaction product of the treatment material and the molten alkali hydroxide after the reaction step in water, thereby generating a precipitate containing the metal elements.

A method for separating metal components from a treatment material containing a silicate and metal elements includes: a reaction step of reacting the treatment material and a molten alkali hydroxide in which bubbles due to water vapor derived from water are generated by heating a hydroxide of an alkali metal or an alkaline-earth metal and the water in a state where the hydroxide and the water coexist, to obtain a reaction product; and a first precipitation step of dissolving the reaction product of the treatment material and the molten alkali hydroxide after the reaction step in water, thereby generating a precipitate containing the metal elements.

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.

A glass ceramic and a preparation method thereof include a step of melting calcined electrolytic manganese slag to obtain molten glass. The molten glass is sequentially molded, nucleated, and crystallized to obtain the glass ceramic. The calcined electrolytic manganese slag is taken as a raw material, so that harmful gases are not generated in the raw material melting process, and secondary pollution is not caused. The preparation method provided by the present invention has the advantages of simple operation, high utilization rate of electrolytic manganese slag and low cost. Moreover, the prepared glass ceramic has good mechanical properties and corrosion resistance.