Abstract: Provided is a method that allows for efficient removal of an impurity metal, and further, the recovery of a valuable metal with high efficiency. The method for recovering a valuable metal (Cu, Ni, and Co) includes the steps of: preparing a charge comprising at least a valuable metal as a raw material; heating and melting the raw material to form an alloy and a slag; and separating the slag to recover the alloy containing the valuable metal, wherein the heating and melting of the raw material comprises charging the raw material into a furnace of an electric furnace equipped with an electrode therein, and further melting the raw material by means of Joule heat generated by applying an electric current to the electrode, or heat generation of an arc itself, and thereby separating the raw material into a molten alloy and a molten slag present over the alloy.

Abstract: Provided is an efficient method for determining the completion of discharging waste batteries, the method being capable of accurately identifying the discharging states of the charge remaining in the waste batteries and appropriately determining the completion of discharging without measuring the residual voltage of each of the waste batteries. The method for determining the completion of discharging waste batteries according to the present invention is characterized in that after immersing the waste batteries in a conductive liquid, the concentration of hydrogen gas produced from the liquid is measured, thereby determining the completion of discharging the charge remaining in the waste batteries.

Abstract: The object of the present invention is to provide a method for recovering a rare earth element, which is capable of efficiently recovering a rare earth element with high recovery rate without using any expensive chemicals, solvents or the like. In the present invention, a water-soluble salt other than sulfate ions is allowed to coexist with an aqueous solution that contains a rare earth element, and then an alkali metal sulfate is added to the aqueous solution, thereby producing a precipitate of a double sulfate of the rare earth element.

Abstract: The object of the present invention is to provide a method for recovering a rare earth element, which is capable of efficiently recovering a rare earth element with high recovery rate without using any expensive chemicals, solvents or the like. In the present invention, a water-soluble salt other than sulfate ions is allowed to coexist with an aqueous solution that contains a rare earth element, and then an alkali metal sulfate is added to the aqueous solution, thereby producing a precipitate of a double sulfate of the rare earth element.

Abstract: Provided is an efficient method for determining the completion of discharging waste batteries, the method being capable of accurately identifying the discharging states of the charge remaining in the waste batteries and appropriately determining the completion of discharging without measuring the residual voltage of each of the waste batteries. The method for determining the completion of discharging waste batteries according to the present invention is characterized in that after immersing the waste batteries in a conductive liquid, the concentration of hydrogen gas produced from the liquid is measured, thereby determining the completion of discharging the charge remaining in the waste batteries.

Abstract: Provided is a battery pack processing apparatus and a processing method with which discharge can be performed in a short time when a battery pack is discharged by immersing the battery pack in a discharge liquid. A processing apparatus A is for discharging a battery pack P having single cells c and a case b by immersing the battery pack P in the discharge liquid. The processing apparatus A includes an aperture-forming machine 20 forming an aperture through which the discharge liquid can flow inside the case b by pressurizing the battery pack P. A state can thus be achieved which is the same as the state that results if the single cells c accommodated in the case b are individually immersed in the discharge liquid. A protection circuit f for preventing an over-discharge is prevented from suppressing a discharge current from the battery pack P, enabling the discharge in a short time.

Abstract: Provided is a battery pack processing apparatus and a processing method with which discharge can be performed in a short time when a battery pack is discharged by immersing the battery pack in a discharge liquid. A processing apparatus A is for discharging a battery pack P having single cells c and a case b by immersing the battery pack P in the discharge liquid. The processing apparatus A includes an aperture-forming machine 20 forming an aperture through which the discharge liquid can flow inside the case b by pressurizing the battery pack P. A state can thus be achieved which is the same as the state that results if the single cells c accommodated in the case b are individually immersed in the discharge liquid. A protection circuit f for preventing an over-discharge is prevented from suppressing a discharge current from the battery pack P, enabling the discharge in a short time.