Abstract: A method for recovering platinum group metals, includes melting a material to be treated containing platinum group metals, under heating in a furnace, along with a copper source material containing at least one kind of metallic copper and copper oxide, a flux component, and a reducing agent. The molten metal absorbing the platinum group metals is separated from a slag oxide through difference in specific gravity. The molten metal absorbing the platinum group metals is subjected to an oxidation treatment. An oxide layer containing as a major component copper oxide and a molten metal containing as a major component metallic copper containing the platinum group metals concentrated therein are separated through difference in specific gravity. A silver content in the molten metal separated in melting under heating is controlled to 2,000 ppm or more and 8,000 ppm or less, thereby recovering platinum group metals with high efficiency.

Abstract: There is provided a method for recovering PGM, in which at least one base metal oxide selected from a group consisting of copper oxide, iron oxide, tin oxide, nickel oxide and lead oxide is added to and melted in a molten slag, and a PGM alloy contained in the molten slag is recovered.

Abstract: A method of suppressing a distribution of PGM into a Cu2O slag in an oxidation smelting of a method of recovering PGM, is provided, including: carrying out reduction smelting to a treatment target member containing PGM, Cu and/or Cu2O, and flux, to thereby generate a molten slag and a Cu alloy containing PGM; and oxidizing and melting the Cu alloy containing the PGM, to thereby generate a Cu2O slag containing PGM and the Cu alloy, with more concentrated PGM concentration than the Cu alloy containing the PGM, wherein when carrying out the oxidation smelting, acidic oxide or basic oxide is added.

Abstract: Provided is a method of unevenly distributing a specific element in a copper phase out of platinum group elements that exist in the copper phase, including further adding copper into a molten copper phase containing the platinum group elements including at least rhodium, thereby increasing a distribution ratio of rhodium in the molten copper phase.

Abstract: Provided is a method of unevenly distributing a specific element in a copper phase out of platinum group elements that exist in the copper phase, including further adding copper into a molten copper phase containing the platinum group elements including at least rhodium, thereby increasing a distribution ratio of rhodium in the molten copper phase.

Abstract: A method of suppressing a distribution of PGM into a Cu2O slag in an oxidation smelting of a method of recovering PGM, is provided, including: carrying out reduction smelting to a treatment target member containing PGM, Cu and/or Cu2O, and flux, to thereby generate a molten slag and a Cu alloy containing PGM; and oxidizing and melting the Cu alloy containing the PGM, to thereby generate a Cu2O slag containing PGM and the Cu alloy, with more concentrated PGM concentration than the Cu alloy containing the PGM, wherein when carrying out the oxidation smelting, acidic oxide or basic oxide is added.

Abstract: Provided is an arsenic-containing solid comprising 100 parts by mass of a scorodite-type iron-arsenic compound and at least 1 part by mass of an iron oxide compound added thereto, in which the scorodite-type iron-arsenic compound is produced by adding an oxidizing agent to an aqueous acidic solution that contains a 5-valent arsenic (V) ion and a 2-valent iron (II) ion, then promoting the precipitation of an iron-arsenic compound with stirring the liquid, and finishing the precipitation thereof within a range where the pH of the liquid is at most 1.2. The iron oxide compound includes goethite, hematite and their mixture, preferably having a BET specific surface area of at least 3 m2/g, more preferably at least 20 m2/g.

Abstract: Scorodite-type iron-arsenic compound particles in which the particle surface layer part comprise an iron-rich layer having an Fe/As molar ratio of at least 1.24. The particles can be obtained in a reaction process of feeding an oxygen-containing gas to an aqueous solution containing an arsenic(V) ion and an iron(II) ion to precipitate a scorodite-type iron-arsenic compound crystal at a pH of at most 2, in which an oxidizing agent is further added to the liquid before the end of the reaction (treatment A). The particles may also be obtained by a method comprising keeping a scorodite-type iron-arsenic compound particle of good crystallinity in contact with an iron ion-containing aqueous solution having a controlled pH of from 2 to 9 at 0 to 90° C. (treatment B). The scorodite-type iron-arsenic particles have good filterability and excellent arsenic release-preventing effect.

Abstract: An apparatus for recovering platinum group elements comprises a furnace body having an interior space substantially shot off from external air, a material charging port and an exhaust port provided in an upper half of the furnace body, at least two fluid discharge ports provided in a lower half of the furnace body at different height levels. a material charging chute connected to the material charging port. an exhaust unit connected to the exhaust port; and electrodes for passing electric current through and heating material charged into the furnace. The material charging chute is equipped with a vertical two stage shutter so as to maintain airtightness when material is charged into the interior space of the furnace.

Abstract: Provided is a method of easily producing scorodite which is stable and has excellent filtering properties with excellent reproducibility and without using complex operations, when processing arsenic that is included in non-ferrous smelting intermediates, and particularly when processing copper arsenic compounds in the form of an intermetallic compound. Scorodite is produced by a leaching step of leaching arsenic from a non-ferrous melting intermediate containing a copper arsenic compound in the form of an intermetallic compound in the presence of a sulfidizing agent and an oxidizing agent, a solution adjusting step of oxidizing trivalent arsenic to pentavalent arsenic by adding the oxidizing agent to the leaching solution, and a crystallizing step of converting the arsenic in the adjusted solution to scorodite crystals.

Abstract: To provide a method of generating, with good reproducibility and ease and without complicated operations, scorodite which satisfies the elution standard (in accordance with Notification of No. 13 of Japanese Environment Agency) and which has good filterbility and stability for processing arsenic contained in a diarsenic trioxide form. A method of processing diarsenic trioxide, including: a leaching step of adding water to diarsenic trioxide to produce slurry, heating the slurry, and leaching arsenic while adding an oxidant to obtain leachate; a deoxidization step of removing the oxidant so as to obtain an adjusted solution; and a crystallizing step of converting arsenic in the adjusted solution to scorodite crystal.

Abstract: Provided is a method of easily producing easily-filterable and stable scorodite that meets the leaching standard (conformance to Japanese Environmental Agency Notice 13) with excellent reproducibility and without using complex operations, when processing arsenic that is included in non-ferrous smelting intermediates, and particularly when processing arsenic in the form of a sulfide. Scorodite is produced by a leaching step of leaching arsenic from a non-ferrous melting intermediate containing arsenic in the weakly acid region, a solution adjusting step of oxidizing trivalent arsenic to pentavalent arsenic by adding an oxidizing agent to the leaching solution, and a crystallizing step of converting the arsenic in the adjusted solution to scorodite crystals.

Abstract: To extract arsenic from intermediates containing arsenic, to outside the system in stable form. A method of processing non-ferrous smelting intermediate containing arsenic in sulfide form and a non-ferrous smelting intermediate containing arsenic and copper as metal; a solution adjusting step of adding an oxidation agent to the leaching solution to oxidize trivalent arsenic to pentavalent arsenic and obtain an adjusting solution; and a crystallization step of converting arsenic in the adjusted solution to scorodite crystals.

Abstract: There is provided an iron arsenate powder which is produced from an arsenic containing solution and wherein the concentration of arsenic eluted or released from the powder is very low. The iron arsenate powder is a powder of dihydrate of iron arsenate, which has a crystal structure of rhombic system and which has lattice constants of a=0.8950 to 0.8956 nm, b=1.0321 to 1.0326 nm and c=1.0042 to 1.0050 nm at room temperatures and atmospheric pressure. The iron arsenate powder can be produced by a method comprising the steps of: adding ferrous ions to an arsenic containing solution to cause the molar ratio (Fe/As) of iron to arsenic in the solution to be not lower than 1; adding an oxidizing agent to the solution; heating the solution to a temperature of not lower than 70° C. while stirring the solution, to allow a reaction; and carrying out a solid-liquid separation to wash the obtained solid part.

Abstract: There is provided an iron arsenate powder which is produced from an arsenic containing solution and wherein the concentration of arsenic eluted or released from the powder is very low. The iron arsenate powder is a powder of dihydrate of iron arsenate, which has a crystal structure of rhombic system and which has lattice constants of a=0.8950 to 0.8956 nm, b=1.0321 to 1.0326 nm and c=1.0042 to 1.0050 nm at room temperatures and atmospheric pressure. The iron arsenate powder can be produced by a method comprising the steps of: adding ferrous ions to an arsenic containing solution to cause the molar ratio (Fe/As) of iron to arsenic in the solution to be not lower than 1; adding an oxidizing agent to the solution; heating the solution to a temperature of not lower than 70° C. while stirring the solution, to allow a reaction; and carrying out a solid-liquid separation to wash the obtained solid part.

Abstract: A method for recovering platinum group elements comprises charging into a closed electric furnace and melting, together with flux components and a reducing agent, a platinum group element-containing substance to be processed and a copper source material containing copper oxide, sinking molten metal of primarily metallic copper below a molten slag layer of primarily oxides, and enriching the platinum group elements in the molten metal sunk below, and is characterized in that molten slag whose copper content has decreased to 3.0 wt % or less is discharged from the electric furnace and that the copper source material charged into the electric furnace is a granular copper source material of a grain diameter of not less than 0.1 mm and not greater than 10 mm.

Abstract: A method for recovering platinum group elements comprises charging into a closed electric furnace and melting, together with flux components and a reducing agent, a platinum group element-containing substance to be processed and a copper source material containing copper oxide, sinking molten metal of primarily metallic copper below a molten slag layer of primarily oxides, and enriching the platinum group elements in the molten metal sunk below, and is characterized in that molten slag whose copper content has decreased to 3.0 wt % or less is discharged from the electric furnace and that the copper source material charged into the electric furnace is a granular copper source material of a grain diameter of not less than 0.1 mm and not greater than 10 mm.

Abstract: To provide a method of generating, with good reproducibility and ease and without complicated operations, scorodite which satisfies the elution standard (in accordance with Notification of No. 13 of Japanese Environment Agency) and which has good filterbility and stability for processing arsenic contained in a non-ferrous smelting intermediate, particularly, for processing a diarsenic trioxide form. A method of processing diarsenic trioxide, including: a leaching step of adding water and alkali to a non-ferrous smelting intermediate that contains diarsenic trioxide to produce slurry, heating the slurry, and leaching arsenic; a solution adjusting step of adding an oxidizing agent to the leachate to oxidize trivalent arsenic to pentavalent arsenic so as to obtain an adjusted solution; and a crystallizing step of converting arsenic in the adjusted solution to scorodite crystal.

Abstract: The object is to remove arsenic in a stable form from an arsenic-containing smelting intermediate product. Thus, disclosed is a method for treating an arsenic-containing nonferrous smelting intermediate product, which comprises: a leaching step of subjecting a mixed slurry of a nonferrous smelting intermediate product containing arsenic in the form of a sulfide and a nonferrous smelting intermediate product containing arsenic and metal copper to the oxidation/leaching in an acidic range to produce a leaching solution; a solution preparation step of adding an oxidizing agent to the leaching solution to oxidize trivalent arsenic into pentavalent arsenic, thereby producing a preparation solution; and a crystallization step of converting arsenic contained in the preparation solution into a scorodite crystal.

Abstract: Provided is a method of easily producing easily-filterable and stable scorodite that meets the leaching standard (conformance to Japanese Environmental Agency Notice 13) with excellent reproducibility and without using complex operations, when processing arsenic that is included in non-ferrous smelting intermediates, and particularly when processing arsenic in the form of a sulfide. Scorodite is produced by a leaching step of leaching arsenic from a non-ferrous melting intermediate containing arsenic in the weakly acid region, a solution adjusting step of oxidizing trivalent arsenic to pentavalent arsenic by adding an oxidizing agent to the leaching solution, and a crystallizing step of converting the arsenic in the adjusted solution to scorodite crystals.