The present disclosure provides a system and a method for reducing metal oxide to metal M.sup.1.

The invention comprises methods and apparatuses for the electrorefining of Mg from Al or Mg alloy scrap. The invention utilizes the density and charge features of Mg present in a melted alloy to continuously extract Mg and Mg alloys from a melted Al alloy feed.

The invention comprises methods and apparatuses for the electrorefining of Mg from Al or Mg alloy scrap. The invention utilizes the density and charge features of Mg present in a melted alloy to continuously extract Mg and Mg alloys from a melted Al alloy feed.

There is described a method of reprocessing spent nuclear fuel. The spent nuclear fuel is added to an electro-reduction cell containing a halide salt electrolyte at a temperature above the melting point of the metallic form of uranium and higher actinides present in the spent nuclear fuel. The cell is operated so as to electrochemically reduce the spent nuclear fuel to form an alloy of uranium and higher actinides present in the spent nuclear fuel, wherein electrochemical reduction is continued until a concentration of unreduced components of the spent nuclear fuel is sufficiently low for the alloy to agglomerate.

There is described a method of reprocessing spent nuclear fuel. The spent nuclear fuel is added to an electro-reduction cell containing a halide salt electrolyte at a temperature above the melting point of the metallic form of uranium and higher actinides present in the spent nuclear fuel. The cell is operated so as to electrochemically reduce the spent nuclear fuel to form an alloy of uranium and higher actinides present in the spent nuclear fuel, wherein electrochemical reduction is continued until a concentration of unreduced components of the spent nuclear fuel is sufficiently low for the alloy to agglomerate.

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 -MnAl phase and crystal grains containing a 2-MnAl phase. Assuming that the area of the crystal grains containing the -MnAl phase in a predetermined cross section is B, and the area of the crystal grains containing the 2-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 -MnAl phase and those containing the 2-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 -MnAl phase and crystal grains containing a 2-MnAl phase. Assuming that the area of the crystal grains containing the -MnAl phase in a predetermined cross section is B, and the area of the crystal grains containing the 2-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 -MnAl phase and those containing the 2-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.

A MnAl alloy according to the present invention exhibits metamagnetism and has crystal grains containing a -MnAl phase and crystal grains containing a 2-MnAl phase and a -MnAl phase. When the ratio of the -MnAl phase is A, 75%A99% is preferably satisfied, and when the ratios of the 2-MnAl phase and -MnAl phase are B and C, respectively, B<C is preferably satisfied. Thus, it is possible to obtain metamagnetism over a wide temperature range, particularly, over a temperature range of 100 C. to 200 C. and to enhance saturation magnetization.

Provided is a method for electrowinning neodymium compound. The method includes providing a fluoride-based electrolyte through an opening defined in an electrolytic bath including a cathode and an anode. The method includes providing granules, each including a neodymium compound and having at least one cavity defined therein, through the opening defined in the electrolytic bath. The method includes dissolving at least a portion of the granule in a molten salt of the fluoride-based electrolyte. The method also includes reducing neodymium at the cathode. The cavity is defined inside or on the surface of the granule, and the apparent density of the granules is lower than the density of the molten salt. The method proposed has an improved process compared to those of the related art.

Provided is a method for electrowinning neodymium compound. The method includes providing a fluoride-based electrolyte through an opening defined in an electrolytic bath including a cathode and an anode. The method includes providing granules, each including a neodymium compound and having at least one cavity defined therein, through the opening defined in the electrolytic bath. The method includes dissolving at least a portion of the granule in a molten salt of the fluoride-based electrolyte. The method also includes reducing neodymium at the cathode. The cavity is defined inside or on the surface of the granule, and the apparent density of the granules is lower than the density of the molten salt. The method proposed has an improved process compared to those of the related art.