Dowa Metals & Mining Co., Ltd.

Toyo Ink Manufacturing Company

Unicharm Corporation

Dowa Metals & Minning Co., Ltd.

Masayoshi Matsumoto

Tetsuo Fujita

Yusuke Sato

Hironobu Mikami

Masami Oouchi

Mitsuo Abumiya

Toru Kurihashi

Michio Takayama

Masami Kuwahara

Takeshi Hirose

Takayoshi Konishi

Naohito Takeuchi

Ryuichiro Kurata

Mitsuo Abuyima

Nobuo Morohashi

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.

Method of alkali processing substance containing arsenic

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.

Method of processing copper arsenic compound

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.

Method of processing diarsenic trioxide

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.

Method of processing non-ferrous smelting intermediate containing arsenic

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.

Method of processing non-ferrous smelting intermediates containing arsenic

A process of accelerating electrons with a voltage applied thereto in a vacuum, guiding the accelerated electrons into a normal-pressure atmosphere, and irradiating the electron beam (EB) onto an object. The electron beam irradiation process uses a vacuum tube-type electron beam irradiation apparatus, and with the acceleration voltage for generating an electron beam set at a value smaller than 100 kV, the electron beam is irradiated onto the object.

Electron beam irradiation process and an object irradiated with an electron beam

A water-disintegratable cleaning sheet consisting of a fibrous sheet having incorporated thereinto, a binder of alkylcellulose; an electrolyte, and (a) a copolymer of a polymerizable acid anhydride and other compounds and/or (b) an amino acid. The water-disintegratable cleaning sheet has excellent water disintegratability and wet strength and further it is not degraded in the water disintegratability and wet strength after storage at high temperatures.

Growing community of inventors

Tokyo, Japan

Masayoshi Matsumoto