Abstract: The present zinc recovery method is characterized in including a dissolving process of treating a raw material containing zinc with an alkaline fluid at a temperature equal to or higher than 100° C. to dissolve zinc contained in the raw material, and a recovering process of recovering zinc extracted from the raw material by the dissolving process.

Abstract: A zinc production method further includes chlorine-concentration adjusting processes 101, 101?, and 105 of using an alkali hydroxide aqueous solution as an extraction solvent for selectively extracting zinc components in a zinc-containing aqueous-solution generating process 102, and separating chlorine components contained in electric arc furnace dust or secondary dust to decrease the chlorine concentration of a zinc-containing aqueous solution at a stage prior to an electrolyzing process 103.

Abstract: A zinc production method includes a reaction step such as a leaching step (101) of bringing electric arc furnace dust (1) containing zinc oxide or the like into contact with a chlorine gas (8) to obtain a zinc oxide component in the electric arc furnace dust (1) or the like as crude zinc chloride (3), a purification step (102) of heating the crude zinc chloride (3) obtained at the reaction step to produce zinc chloride vapor, and cooling and condensing the zinc chloride vapor, thereby obtaining purified zinc chloride (6), and an electrolysis step (103) of electrolyzing the purified zinc chloride (6) obtained at the purification step (102) in a molten state to obtain a zinc melt (9) and the chlorine gas (8).

Abstract: A zinc production method including a chlorination step 101 at which crude zinc chloride vapor 3 and an oxygen gas 2 are obtained by bringing electric furnace dust 1 containing zinc oxide or secondary dust 1 generated at the time of reducing the electric furnace dust in a reduction furnace into contact with a mixed gas containing a chlorine gas 8 and an oxygen-containing gas 10, converting a zinc oxide component in the electric furnace dust 1 or the secondary dust 1 into zinc chloride, and vaporizing the zinc chloride. The zinc production method further includes purification steps 102, 104, and 105 at which a zinc chloride component contained in the crude zinc chloride vapor 3 is separated from components 5 and 7 other than zinc chloride contained in the crude zinc chloride vapor 3 to obtain a purified zinc chloride melt 6, and an electrolysis step 103 at which the purified zinc chloride melt 6 is electrolyzed to obtain a zinc melt 9 and the chlorine gas 8.

Abstract: A zinc production method includes a reaction step such as a leaching step (101) of bringing electric arc furnace dust (1) containing zinc oxide or the like into contact with a chlorine gas (8) to obtain a zinc oxide component in the electric arc furnace dust (1) or the like as crude zinc chloride (3), a purification step (102) of heating the crude zinc chloride (3) obtained at the reaction step to produce zinc chloride vapor, and cooling and condensing the zinc chloride vapor, thereby obtaining purified zinc chloride (6), and an electrolysis step (103) of electrolyzing the purified zinc chloride (6) obtained at the purification step (102) in a molten state to obtain a zinc melt (9) and the chlorine gas (8).

Abstract: A gas purification apparatus, highly purifying gas containing salt derived from molten salt stored in a vessel (10), is provided with a reflux mechanism (35, 42) liquefying the salt, contained in the gas, for return to the molten salt in the vessel, and a filtration mechanism (39, 44) disposed in an exhaust flow path of the gas on a downstream stage of the reflux mechanism.

Abstract: A gas purification apparatus, highly purifying gas containing salt derived from molten salt stored in a vessel (10), is provided with a reflux mechanism (35, 42) liquefying the salt, contained in the gas, for return to the molten salt in the vessel, and a filtration mechanism (39, 44) disposed in an exhaust flow path of the gas on a downstream stage of the reflux mechanism.

Abstract: In order to ensure an easy operation, a decreased cost in maintenance and installation, and a safe and effective use of chlorine gas generated in a closed system, a new method for treating an etchant is offered. The method comprises the following steps of; 1 treating an etchant including copper (I) chloride or ferric chloride containing copper by means of an electrolysis using a diaphragm to withdraw copper electrolytically deposited in a cathode cell, 2 supplying chlorine gas generated in an anode cell into another etchant used in an etching process, thereby enabling the etchant to be regenerated.