The present invention discloses a short process preparation technology of sintered NdFeB magnets from the NdFeB sludge, which relates to a field of recycle technology of NdFeB sludge. The present invention comprises the following steps: water bath distillation of organics in sludge, ultrasonic cleaning, calcium reduction and diffusion, ultrasonic rinsing in a magnetic field and drying, powders mixing and sintering. NdFeB sludge as raw materials was directly prepared from recycled sintered magnets with high magnetic properties. Most of the organics in the sludge could be removed by a vacuum distillation process with stepwise heating. The ultrasonic rinsing process in a magnetic field could effectively remove the remaining organics. The recycled sintered magnets exhibited good maximum energy product [(BH).sub.max] of 35.26 MGOe. The present invention has important features, such as the short processing time, efficient environmental protection, high recycling rate and effective utilization rate of rare earth metals.

The present invention discloses a short process preparation technology of sintered NdFeB magnets from the NdFeB sludge, which relates to a field of recycle technology of NdFeB sludge. The present invention comprises the following steps: water bath distillation of organics in sludge, ultrasonic cleaning, calcium reduction and diffusion, ultrasonic rinsing in a magnetic field and drying, powders mixing and sintering. NdFeB sludge as raw materials was directly prepared from recycled sintered magnets with high magnetic properties. Most of the organics in the sludge could be removed by a vacuum distillation process with stepwise heating. The ultrasonic rinsing process in a magnetic field could effectively remove the remaining organics. The recycled sintered magnets exhibited good maximum energy product [(BH).sub.max] of 35.26 MGOe. The present invention has important features, such as the short processing time, efficient environmental protection, high recycling rate and effective utilization rate of rare earth metals.

A samarium-iron-nitrogen alloy powder according to one embodiment of the present invention is characterized in that a value obtained by dividing the hydrogen content of the samarium-iron-nitrogen alloy powder by the BET specific surface area of the samarium-iron-nitrogen alloy powder is less than or equal to 400 ppm/(m.sup.2/g), and a value obtained by dividing the oxygen content of the samarium-iron-nitrogen alloy powder by the BET specific surface area of the samarium-iron-nitrogen alloy powder is less than or equal to 11,000 ppm/(m.sup.2/g).

A samarium-iron-nitrogen alloy powder according to one embodiment of the present invention is characterized in that a value obtained by dividing the hydrogen content of the samarium-iron-nitrogen alloy powder by the BET specific surface area of the samarium-iron-nitrogen alloy powder is less than or equal to 400 ppm/(m.sup.2/g), and a value obtained by dividing the oxygen content of the samarium-iron-nitrogen alloy powder by the BET specific surface area of the samarium-iron-nitrogen alloy powder is less than or equal to 11,000 ppm/(m.sup.2/g).

The invention relates to a method for forming powder particles, wherein the method comprises feeding a start material mixture including more than one constituents in the form of granules into a reactor comprising a reaction zone and a heat source, performing thermal synthesis in the reaction zone in which the start material mixture is moved and the constituents of the start material mixture react in the presence of heat so that the reaction is started by means of heat of the reactor and energy of the start material mixture is released in the form of heat in order to achieve the reaction, and producing powder particles during the reaction. Further, the invention relates to a powder particle product.

The invention relates to a method for forming powder particles, wherein the method comprises feeding a start material mixture including more than one constituents in the form of granules into a reactor comprising a reaction zone and a heat source, performing thermal synthesis in the reaction zone in which the start material mixture is moved and the constituents of the start material mixture react in the presence of heat so that the reaction is started by means of heat of the reactor and energy of the start material mixture is released in the form of heat in order to achieve the reaction, and producing powder particles during the reaction. Further, the invention relates to a powder particle product.

The invention relates to a method for forming powder particles, wherein the method comprises feeding a start material mixture including more than one constituents in the form of granules into a reactor comprising a reaction zone and a heat source, performing thermal synthesis in the reaction zone in which the start material mixture is moved and the constituents of the start material mixture react in the presence of heat so that the reaction is started by means of heat of the reactor and energy of the start material mixture is released in the form of heat in order to achieve the reaction, and producing powder particles during the reaction. Further, the invention relates to a powder particle product.

Disclosed is a method for preparing vanadium or vanadium alloy powder from a vanadium-containing raw material through a shortened process, including: calcinating a mixture of a vanadium-containing raw material and an alkali compound for oxidation to form a water-soluble vanadate; purifying the vanadate followed by vanadium precipitation to produce an intermediate CaV.sub.2O.sub.6 with high purity; dissolving CaV.sub.2O.sub.6 in a molten-salt medium together with other raw materials to form a uniform reaction system; and introducing a reducing agent to the system followed by separation, washing and drying to produce vanadium or vanadium alloy powder having a particle size of 50-800 nm and a purity of 99.0 wt % or more. The method can continuously process vanadium-containing raw materials to prepare vanadium or vanadium alloy powder.

Disclosed is a method for preparing vanadium or vanadium alloy powder from a vanadium-containing raw material through a shortened process, including: calcinating a mixture of a vanadium-containing raw material and an alkali compound for oxidation to form a water-soluble vanadate; purifying the vanadate followed by vanadium precipitation to produce an intermediate CaV.sub.2O.sub.6 with high purity; dissolving CaV.sub.2O.sub.6 in a molten-salt medium together with other raw materials to form a uniform reaction system; and introducing a reducing agent to the system followed by separation, washing and drying to produce vanadium or vanadium alloy powder having a particle size of 50-800 nm and a purity of 99.0 wt % or more. The method can continuously process vanadium-containing raw materials to prepare vanadium or vanadium alloy powder.

A method for preparing a tantalum power of capacitor grade, comprising: solid tantalum nitride is added when potassium fluotantalate is reduced by sodium. The method increases the nitrogen content in the tantalum powder, and at the same time improves the electrical performance of the tantalum powder. The specific capacitance is increased, and the leakage current and loss is improved. The qualification rate of the anode and the capacitor product is also improved. The method is characterized in that the nitrogen in the tantalum nitride diffuses between the particles of the tantalum powder, with substantially no loss, and thus the nitrogen content is accurate and controllable.