Sumitomo Metal Mining Company, Ltd.

Kochi University

Kyushu University

Kochi University, National University Corporation

Yoshitomo Ozaki

Shin-Ichi Heguri

Hideki Ohara

Shin-ichi Heguri

Kazuyuki Takaishi

Tatsuya Higaki

Osamu Ikeda

Yohei Kudo

Tomoaki Yoneyama

Osamu Nakai

Keisuke Shibayama

Hiroshi Kobayashi

Keiji Kudo

Hirofumi Shouji

Masaki Imamura

Kazumichi Yanagisawa

Hidemasa Nagai

Toshihiko Nagakura

Junhao Zhang

Takayuki Nakai

Itsumi Matsuoka

Shin-ya Matsumoto

Naoyuki Tsuchida

Ryo-Ma Yamaguma

Satoshi Asano

Masahiro Goto

Hiroyuki Mitsui

Ryozo Ushio

Fukiko Kubota

Yuzo Baba

Shinichi Heguri

Manabu Enomoto

Shinya Matsumoto

Susumu Makino

Yuji Aoki

Shin-Ya Matsumoto

Hideki Sasaki

Satoshi Matsumoto

Junichi Takahashi

Masatoshi Takano

Yasumasa Kan

Hirofumi Shoji

Toshirou Tan

Yoji Kyoda

Yu Yamashita

Jun-ichi Takahashi

Norihisa Toki

Atsushi Idegami

Jiro Hayata

Keiji Kudou

Jun-Ichi Takahashi

Ryoma Yamaguma

Yasuo Yoshii

Toru Kitazaki

Takao Ooishi

Atsushi Goda

Sunao Kanesaka

Ryo-ma Yamaguma

Yasuo Doi

A method for recovering scandium, by which scandium is able to be recovered from nickel oxide ore. The present invention comprises: a leaching step Sfor obtaining a leachate by leaching a nickel oxide ore containing scandium with use of sulfuric acid; a neutralization step by adding a neutralizing agent thereto; a sulfurization step by adding a sulfurizing agent to the post-neutralization solution; an ion exchange step by bringing the post-sulfurization solution into contact with a chelating resin; a dissolution step by obtaining a precipitate of scandium hydroxide by adding an alkali into the scandium eluent, and subsequently adding an acid solution to the scandium hydroxide; a solvent extraction step by bringing the scandium acid dissolution liquid into contact with a neutral extractant; and a scandium recovery step by adding oxalic acid to the extraction residue and subsequently roasting the salt of scandium oxalate.

Method for recovering scandium

Provided is a method for producing high density nickel powder particularly having a median diameter of 100 to 160 &#x3bc;m by controlling a particle size of nickel powder. The method includes: performing an initial operation by charging a pressure vessel equipped with a stirrer with a nickel ammine complex solution containing nickel in the concentration of 5 to 75 g/L together with seed crystals in the amount of 5 to 200 g per liter of the solution, increasing the temperature of the solution, and performing a reduction reaction with hydrogen by blowing hydrogen gas into the pressure vessel, thereby obtaining the nickel contained in the nickel ammine complex solution as nickel powder; and thereafter, performing a specified operation A repeatedly at least once to obtain the nickel powder having the median diameter of 100 to 160 &#x3bc;m and a bulk density of 1 to 4.5 g/cm.

Method for producing high density nickel powder

A method for producing nickel powder sequentially includes: a mixing step of adding, to a nickel ammine sulfate complex solution, an insoluble solid as seed crystals and a polyacrylate or lignosulfonate as a dispersant to form a mixed slurry; and a reduction and precipitation step of charging a reaction vessel with the mixed slurry and blowing hydrogen gas into the mixed slurry in the reaction vessel to reduce nickel complex ions in the mixed slurry to form nickel precipitate on the surface of the insoluble solid, wherein the amount of the dispersant added in the mixing step is controlled to control the number of the nickel powder obtained by formation of the nickel precipitate in the reduction and precipitation step.

Method for producing nickel powder

A nickel sulfate amine complex liquid and nickel powder having a particle diameter of 0.1 &#x3bc;m to 300 &#x3bc;m are supplied to a reaction container, hydrogen gas is continuously supplied while the inside of the reaction container is maintained at 150&#xb0; C. to 250&#xb0; C., and the pressure is set to 2.5 MPa to 3.5 MPa, whereby nickel ions in the nickel sulfate amine complex liquid are reduced to nickel and deposited on the surfaces of the nickel powder supplied to the reaction container, a reacted slurry including the nickel sulfate amine complex liquid and the nickel powder is then transferred to a pressurized storage container at the same or slightly lower pressure than the internal pressure of the reaction container, and the pressure of the pressurized storage container to which the reacted slurry is transferred is then reduced, after which the reacted slurry is extracted from the pressurized storage container.

Provided a production method for reducing the content level of sulfur and carbon which are impurities in nickel powder to improve the quality of nickel powder produced by a complexing reduction method. The method of producing nickel powder having low carbon and sulfur concentrations includes: a complexing treatment of adding a complexing agent to a nickel sulfate aqueous solution to form a solution containing nickel complex ions; maintaining the solution containing nickel complex ions at a solution temperature of 150 to 250&#xb0; C. in a pressure vessel and blowing hydrogen gas into the solution containing nickel complex ions to perform hydrogen reduction to produce nickel powder; washing the nickel powder with water; and then roasting the nickel powder washed with water in a mixed gas atmosphere of nitrogen and hydrogen.

Method for producing nickel powder having low carbon concentration and low sulfur concentration

Provided is nickel powder obtained by adding seed crystals to a nickel ammine complex solution and performing hydrogen reduction reaction under high temperatures and high pressures, wherein the nickel powder does not produce dust during handling, and a container can be efficiently filled with the nickel powder. The method for producing nickel powder includes: adding seed crystals and a surfactant having a nonionic or anionic functional group to a solution containing a nickel ammine complex to forma mixed slurry; and subjecting the mixed slurry to hydrogen reduction under high temperature and high pressure conditions in a pressure vessel to obtain nickel powder from the mixed slurry.

A wet smelting method for nickel oxide ores from which nickel, cobalt, etc. are recovered is provided with which it is possible to reduce the consumption of an acid in leaching, such as sulfuric acid, and to recover valuable metals. The method comprises: step (A) in which nickel oxide ores as a raw material are separated into a limonite-type ore having a low magnesium content and a saprolite-type ore having a high magnesium content; step (B) in which the saprolite-type ore is subjected to normal-pressure leaching under given standardized leaching conditions using the pressure leachate obtained by pressure leaching in step (C); and step (C) in which the limonite-type ore obtained in step (A) is mixed with the normal-pressure leaching residue obtained in step (B) and the mixture is reacted with sulfuric acid in an acidic atmosphere having a high temperature and a high pressure, thereby conducting pressure leaching.

Wet smelting method for nickel oxide ore

Provided is a method for producing fine nickel powder used as suitable seed crystals for producing nickel powder from a solution containing a nickel ammine sulfate complex. The method for producing nickel powder sequentially comprises: a mixing step of adding, to a solution containing a nickel ammine sulfate complex, an insoluble solid which is insoluble in the solution to form a mixed slurry; a reduction and precipitation step of charging a reaction vessel with the mixed slurry and then blowing hydrogen gas into the mixed slurry in the reaction vessel to reduce nickel complex ions contained in the mixed slurry to form nickel precipitate on a surface of the insoluble solid; and a separation step of separating the nickel precipitate on the surface of the insoluble solid from the surface of the insoluble solid to form nickel powder.

The purpose of the present invention is to recover roughly purified scandium, which is purified to an extent acceptable for a technique for highly purifying scandium, efficiently and without any complicated operation from a neutralization sediment (drainage sediment) generated in neutralizing acid mine drainage which contains a sulfur component. This scandium recovery process includes a washing step (S) for washing a neutralization sediment (drainage sediment) and a dissolution step (S) for subjecting the washed sediment obtained in the washing step (S) to dissolution in an acid. It is preferable that the process further includes a re-dissolution step (S) for subjecting a dissolution residue which remains after the dissolution in the dissolution step (S) to dissolution with an acid. In the washing step (S), the neutralization sediment is washed with a washing liquid until the pH of the post-washing liquid generated in the washing step becomes 6 or higher.

Scandium recovery process

Provided is a method for producing nickel powder from a nickel ammine sulfate complex solution, comprising treatment steps of: (1) a seed crystal production step of producing nickel powder having an average particle size of 0.1 to 5 &#x3bc;m; (2) a seed crystal addition step of adding the nickel powder obtained in the step (1) as seed crystals to form a mixed slurry; (3) a reduction step of forming a reduced slurry containing nickel powder formed by precipitation of a nickel component in the mixed slurry on the seed crystals; and (4) a growth step of performing solid-liquid separation to separate and recover the nickel powder as a solid phase component and then blowing hydrogen gas into a solution prepared by adding the nickel ammine sulfate complex solution to the recovered nickel powder to grow the nickel powder to form high purity nickel powder.

Provided is a method for producing fine nickel powder used as suitable seed crystals for producing nickel powder from a solution containing a nickel ammine sulfate complex. The method for producing nickel powder sequentially includes: a mixing step of adding, to a solution containing a nickel ammine sulfate complex, a dispersant containing a sulfonate and an insoluble solid which is insoluble in the solution to form a mixed slurry; a reduction and precipitation step of charging a reaction vessel with the mixed slurry and then blowing hydrogen gas into the mixed slurry in the reaction vessel to reduce nickel complex ions contained in the mixed slurry to form nickel precipitate on a surface of the insoluble solid; and a separation step of separating the nickel precipitate on the surface of the insoluble solid from the surface of the insoluble solid to form nickel powder.

Provided is a method for recovering scandium, with which it is possible to easily and efficiently recover high-purity scandium from nickel oxide ores. This method for recovering scandium involves passing a solution containing scandium through an ion exchange resin, then subjecting the eluant eluted from the ion exchange resin to solvent extraction and separating the extraction residual liquid and the extraction agent after extraction, then performing an oxalation process on the extraction residual liquid to obtain a scandium oxalate precipitate, and roasting the precipitate to obtain scandium oxide, wherein the method is characterized in that an amine-based extraction agent is used as the extraction agent for solvent extraction.

Method for recovering high-purity scandium

In order to recover high-quality scandium from nickel oxide ores efficiently, this method comprises: a step (S) for feeding Ni oxide ores and sulfuric acid into a pressure vessel, and subjecting the mixture to solid-liquid separation to form a leachate and a leach residue; a step (S) for adding a neutralizing agent to the leachate, and thus forming a neutralization sediment and a post-neutralization fluid; a step (S) for adding a sulfurizing agent to the post-neutralization fluid, and separating the obtained mixture into Ni sulfide and a post-sulfurization fluid; a step (S) for bringing the post-sulfurization fluid into contact with a chelating resin, making Sc adsorbed on the chelating resin, and forming an Sc eluent; a step (S) for bringing the Sc eluent into contact with an extracting agent, adding a back-extraction agent to the extract, and forming back-extracted matter; and a step (S) for roasting the back-extracted matter, and forming Sc oxide.

Scandium recovery method

Magnesium oxide produced by a process is used as a neutralizing agent for preliminary neutralization treatment of a leached slurry obtained by leaching a nickel oxide ore at a high temperature and pressure with sulfuric acid added. A neutralizing agent is added to a leachate, obtained by leaching a nickel oxide ore, to separate impurities, and a sulfurizing agent is added to the resulting neutralized solution to obtain nickel and cobalt sulfides, followed by separating the sulfurized solution; discharge waste water, obtained by adding a neutralizing agent to the sulfurized solution to separate aluminum and manganese, is concentrated to precipitate and separate calcium contained in the discharge waste water as calcium sulfate; the resulting solution is concentrated to precipitate magnesium in the solution as magnesium sulfate; the magnesium sulfate is roasted with a reducing agent to obtain magnesium oxide and a sulfurous gas; and the magnesium oxide is washed.

Hematite manufacturing process and hematite manufactured by same

Provided is a production method for refining iron oxide (hematite), which has such a low sulfur content as to be used as an iron-making raw material, from a leach residue containing iron oxide produced by a high pressure acid leach (HPAL) process. In the method for refining iron oxide for ironmaking by a process of adding sulfuric acid to nickel oxide ore and then leaching nickel from the nickel oxide ore using a pressure vessel, an amount of the sulfuric acid added is 150 kg or more and 220 kg or less per ton of nickel oxide ore.

Method for producing hematite for ironmaking

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Niihama, Japan

Yoshitomo Ozaki