This invention relates to a method of carbothermic process of magnesium production and co-production of calcium carbide, which is particularly suitable for carbothermic process of magnesium production with a mixture of magnesium oxide and calcium oxide as a raw material and carbon as a reducing agent. A mixed powder containing magnesium oxide, calcium oxide and a carbon reducing agent is prepared. The mixed powder is processed into a pelletized furnace feed material, which is placed into a reactor equipped with a heat source. With an absolute pressure P in the reactor being set within the range of 1000 Pa≤P≤atmospheric pressure or to a slightly positive pressure and a reaction temperature T within the range of 11 lg.sup.2P+71 lgP+1210° C.<T<98 lg.sup.2P-129 lgP+1300° C., a smelting reaction is run. Liquid magnesium is obtained through condensation by a condenser connected to the reactor, and after the smelting reaction has finished, calcium carbide is obtained within the reactor. With this method, a potential safety hazard in that a magnesium vapor produced during carbothermic magnesium production, when co-cooled with a CO gas, tends to give rise to a magnesium powder and cause an explosion can be completely avoided, and magnesium production cost can be significantly reduced. This method has a good prospect of industrial application.

This invention relates to a method of carbothermic process of magnesium production and co-production of calcium carbide, which is particularly suitable for carbothermic process of magnesium production with a mixture of magnesium oxide and calcium oxide as a raw material and carbon as a reducing agent. A mixed powder containing magnesium oxide, calcium oxide and a carbon reducing agent is prepared. The mixed powder is processed into a pelletized furnace feed material, which is placed into a reactor equipped with a heat source. With an absolute pressure P in the reactor being set within the range of 1000 Pa≤P≤atmospheric pressure or to a slightly positive pressure and a reaction temperature T within the range of 11 lg.sup.2P+71 lgP+1210° C.<T<98 lg.sup.2P-129 lgP+1300° C., a smelting reaction is run. Liquid magnesium is obtained through condensation by a condenser connected to the reactor, and after the smelting reaction has finished, calcium carbide is obtained within the reactor. With this method, a potential safety hazard in that a magnesium vapor produced during carbothermic magnesium production, when co-cooled with a CO gas, tends to give rise to a magnesium powder and cause an explosion can be completely avoided, and magnesium production cost can be significantly reduced. This method has a good prospect of industrial application.

A method with which Mg can be removed from aluminum alloy melt whose raw material is scrap or the like. Metal removal method includes processing step of forming molten salt layer in contact with aluminum alloy melt containing Mg which covers at least part of the surface of the aluminum alloy melt. This method allows Mg to be taken in from aluminum alloy melt to molten salt layer and removed. Molten salt layer contains specific halogen element that is one or more of Cl or Br and specific metal element that is one or more of Cu, Zn, or Mn. The specific metal element is supplied as an oxide of the specific metal element to the molten salt layer. At that time, the molten salt layer contains Mg. The step of removing Mg is performed by disposing a conductor that bridges the aluminum alloy melt and the molten salt layer.

A method with which Mg can be removed from aluminum alloy melt whose raw material is scrap or the like. Metal removal method includes processing step of forming molten salt layer in contact with aluminum alloy melt containing Mg which covers at least part of the surface of the aluminum alloy melt. This method allows Mg to be taken in from aluminum alloy melt to molten salt layer and removed. Molten salt layer contains specific halogen element that is one or more of Cl or Br and specific metal element that is one or more of Cu, Zn, or Mn. The specific metal element is supplied as an oxide of the specific metal element to the molten salt layer. At that time, the molten salt layer contains Mg. The step of removing Mg is performed by disposing a conductor that bridges the aluminum alloy melt and the molten salt layer.

A system and method that uses a high-temperature condenser to collect magnesium produced by thermal reduction, electrolysis, or distillation. The condenser is a common heat exchanger design (shell/tube, plate/plate, etc.) and uses a heat transfer fluid to cool and condense magnesium gas, e.g., to 200-900° C. under vacuum or pressure conditions. Solid or liquid magnesium is collected in the condenser along with any by-products or impurities at a purity greater than 35 wt-% Mg. Magnesium is subsequently liberated from the condenser by raising the temperature of the system, lowering the pressure, or both, to induce a phase change in the metal, such as melting or distillation, for further purification to, e.g., >90 wt-% Mg.

A system and method that uses a high-temperature condenser to collect magnesium produced by thermal reduction, electrolysis, or distillation. The condenser is a common heat exchanger design (shell/tube, plate/plate, etc.) and uses a heat transfer fluid to cool and condense magnesium gas, e.g., to 200-900° C. under vacuum or pressure conditions. Solid or liquid magnesium is collected in the condenser along with any by-products or impurities at a purity greater than 35 wt-% Mg. Magnesium is subsequently liberated from the condenser by raising the temperature of the system, lowering the pressure, or both, to induce a phase change in the metal, such as melting or distillation, for further purification to, e.g., >90 wt-% Mg.

A pickling production line comprises a material-holding apparatus, a pickling zone, and a water wash zone; the pickling zone and the water wash zone are independently arranged; the material-holding apparatus is filled with magnesium alloy waste, and self-rotates successively in the pickling zone and the water wash zone for pickling and water washing respectively. In the pickling production line for magnesium alloy waste material, the magnesium alloy waste material is pickled and washed more thoroughly; coatings and impurities on the surface of the magnesium alloy waste material are removed, the efficiency of the cleaning and the consistency of the cleaning are high, and each piece of equipment in the entire production line is connected in a compact manner; the invention has a high degree of automation, low environmental pollution, conserves resources, is highly efficient in production, and is suitable for the bulk pickling and cleaning of magnesium alloy waste material.

A pickling production line comprises a material-holding apparatus, a pickling zone, and a water wash zone; the pickling zone and the water wash zone are independently arranged; the material-holding apparatus is filled with magnesium alloy waste, and self-rotates successively in the pickling zone and the water wash zone for pickling and water washing respectively. In the pickling production line for magnesium alloy waste material, the magnesium alloy waste material is pickled and washed more thoroughly; coatings and impurities on the surface of the magnesium alloy waste material are removed, the efficiency of the cleaning and the consistency of the cleaning are high, and each piece of equipment in the entire production line is connected in a compact manner; the invention has a high degree of automation, low environmental pollution, conserves resources, is highly efficient in production, and is suitable for the bulk pickling and cleaning of magnesium alloy waste material.

A method comprises sorting and removing impurities from magnesium alloy waste material, and cleaning and drying said material, the cleaning being high-pressure rinsing, pickling, and water washing, performed in sequence. The method employs high-pressure rinsing during the pretreatment of magnesium alloy waste material; the cleaning effectiveness is excellent, the effectiveness of the removal of impurities from the surface of the magnesium alloy waste material is much better than in conventional processes, and the amount of clean waste material can exceed 90% of the total amount of processed waste material; the clean magnesium alloy waste material obtained from the pretreatment method may be used as the entire raw materials for casting national-standard alloy ingots, the addition of costly high-purity magnesium is unnecessary, and the amount of alloy raw material that must be added is significantly reduced; during processing, little waste material is lost, costs are low, and efficiency is high.

A method comprises sorting and removing impurities from magnesium alloy waste material, and cleaning and drying said material, the cleaning being high-pressure rinsing, pickling, and water washing, performed in sequence. The method employs high-pressure rinsing during the pretreatment of magnesium alloy waste material; the cleaning effectiveness is excellent, the effectiveness of the removal of impurities from the surface of the magnesium alloy waste material is much better than in conventional processes, and the amount of clean waste material can exceed 90% of the total amount of processed waste material; the clean magnesium alloy waste material obtained from the pretreatment method may be used as the entire raw materials for casting national-standard alloy ingots, the addition of costly high-purity magnesium is unnecessary, and the amount of alloy raw material that must be added is significantly reduced; during processing, little waste material is lost, costs are low, and efficiency is high.