The invention provides method for making high coercivity magnetic materials based on FeNi alloys having a L1.sub.0 phase structure, tetratenite, and provides a system for accelerating production of these materials. The FeNi alloy is made by preparing a melt comprising Fe, Ni, and optionally one or more elements selected from the group consisting of Ti, V, Al, B, C, Mo, Ir, and Nb; cooling the melt and applying extensional stress and a magnetic field. This is followed by heating and cooling to form the L10 structure.

A method for manufacturing magnetic alloy powder constituted by magnetic grains whose alloy phase is coated with an oxide film, includes: providing a material powder for magnetic alloy whose Fe content is 96.5 to 99 percent by mass and which also contains Si and at least one of non-Si elements (element M) that oxidize more easily than Fe; and heat-treating the material powder and thus forming an oxide film on a surface of each grain constituting the material powder, to obtain a magnetic alloy powder, wherein a content of Fe in the alloy phase is higher than in the material powder; and at a location in the oxide film where its content of Si is in element distributions in a film thickness direction is highest, the content of Si is higher than a content of Fe, and also higher than its content of element M, at the location.

A method for manufacturing magnetic alloy powder constituted by magnetic grains whose alloy phase is coated with an oxide film, includes: providing a material powder for magnetic alloy whose Fe content is 96.5 to 99 percent by mass and which also contains Si and at least one of non-Si elements (element M) that oxidize more easily than Fe; and heat-treating the material powder and thus forming an oxide film on a surface of each grain constituting the material powder, to obtain a magnetic alloy powder, wherein a content of Fe in the alloy phase is higher than in the material powder; and at a location in the oxide film where its content of Si is in element distributions in a film thickness direction is highest, the content of Si is higher than a content of Fe, and also higher than its content of element M, at the location.

Provided is a method for producing alloy steel, the method comprising producing first alloy steel in a temperature holding furnace; maintaining the first alloy steel at a temperature of no lower than a melting point in the temperature holding furnace; and producing second alloy steel having an alloy content lower than the alloy content in the first alloy steel by melt mixing of the first alloy steel and molten steel. In the producing of the alloy steel, melting and storing of the ferroalloy are continuously performed, and thus, the temperature drop of the ferroalloy may be suppressed or prevented.

Provided is a method for producing alloy steel, the method comprising producing first alloy steel in a temperature holding furnace; maintaining the first alloy steel at a temperature of no lower than a melting point in the temperature holding furnace; and producing second alloy steel having an alloy content lower than the alloy content in the first alloy steel by melt mixing of the first alloy steel and molten steel. In the producing of the alloy steel, melting and storing of the ferroalloy are continuously performed, and thus, the temperature drop of the ferroalloy may be suppressed or prevented.

An NPR non-magnetic steel material for rock bolt and a production method thereof are disclosed. The NPR non-magnetic steel material for rock bolt has a composition, in weight percent, consisting of: C: 0.4-0.7%, MN: 15-20%, Cr: 1-18%, Si: 0.3-3%, Ca: 0.05-0.15%, Cu: ≤0.03%, Ni: ≤0.02%, S: ≤0.001%, P: ≤0.001%, and the rest being Fe and unavoidable impurity elements. The NPR non-magnetic steel material for rock bolt and the production method thereof effectively solve the problems of steel materials for rock bolt in the prior art such as strong magnetism, low tensile strength and low effective elongation. The NPR non-magnetic steel material for rock bolt has a fully-austenitized structure and is non-magnetic, its yield strength is adjustable in the range of 600-1000 MPa, and its elongation is adjustable in the range of 20-60%.

An NPR non-magnetic steel material for rock bolt and a production method thereof are disclosed. The NPR non-magnetic steel material for rock bolt has a composition, in weight percent, consisting of: C: 0.4-0.7%, MN: 15-20%, Cr: 1-18%, Si: 0.3-3%, Ca: 0.05-0.15%, Cu: ≤0.03%, Ni: ≤0.02%, S: ≤0.001%, P: ≤0.001%, and the rest being Fe and unavoidable impurity elements. The NPR non-magnetic steel material for rock bolt and the production method thereof effectively solve the problems of steel materials for rock bolt in the prior art such as strong magnetism, low tensile strength and low effective elongation. The NPR non-magnetic steel material for rock bolt has a fully-austenitized structure and is non-magnetic, its yield strength is adjustable in the range of 600-1000 MPa, and its elongation is adjustable in the range of 20-60%.

Provided is a 600 MPa grade non-oriented electrical steel sheet with excellent magnetic properties, comprising the following chemical elements in mass percentage: 0<C≤0.0035%; Si: 2.0-3.5%; Mn: 0.4-1.2%; P: 0.03-0.2%; Al: 0.4-2.0%; and the balance being Fe and unavoidable impurities. Also provided is a manufacturing method for the 600 MPa grade non-oriented electrical steel as described above, including the following steps: (1) converter smelting, RH refining and casting; (2) hot rolling; (3) normalizing; (4) cold rolling; (5) continuous annealing; and (6) applying an insulation coating to obtain a finished non-oriented electrical steel sheet.

A method for upgrading used or rejected electric battery cells, which include upgradable compounds, such as iron, zinc, manganese, copper, and fixed and volatile carbon, and heavy metals and dangerous compounds. The used or rejected battery cells are introduced as a load into a furnace for melting metal, such as a cupola furnace, a free arc furnace, or an induction furnace. A device for purifying gases produced by the furnace and for capturing and removing noxious elements, such as mercury, chlorides, and fluorides, and heavy molecules such as dioxins, furans, and aromatic substances, is provided in a discharge route of the hot gases, downstream from the melting furnace.

A method for upgrading used or rejected electric battery cells, which include upgradable compounds, such as iron, zinc, manganese, copper, and fixed and volatile carbon, and heavy metals and dangerous compounds. The used or rejected battery cells are introduced as a load into a furnace for melting metal, such as a cupola furnace, a free arc furnace, or an induction furnace. A device for purifying gases produced by the furnace and for capturing and removing noxious elements, such as mercury, chlorides, and fluorides, and heavy molecules such as dioxins, furans, and aromatic substances, is provided in a discharge route of the hot gases, downstream from the melting furnace.