Sumitomo Metal Mining Company, Ltd.

Keisuke Shibayama

Osamu Nakai

Yoshitomo Ozaki

Hiroyuki Mitsui

Hiroshi Kobayashi

Satoshi Matsumoto

Ryozo Ushio

Yoji Kyoda

Atsushi Idegami

Yuji Aoki

Junichi Takahashi

Takayuki Nakai

Tatsuya Higaki

Toru Amano

Hirofumi Shoji

Toshirou Tan

Shinichiro Nakamura

Shinichi Heguri

Norihisa Toki

Sho Shirai

Yasuo Yoshii

Toru Kitazaki

Takao Ooishi

Yoshimoto Ozaki

The present invention provides a chromium-containing water treatment method that allows treatment of water that contains chromium (chromium-containing water) at low cost. A chromium-containing water treatment method according to the present invention comprises: a reduction step in which chromium-containing waterand a liquidcontaining 5-50 ppm of hydrogen sulfide are mixed, and the mixture is adjusted to pH 3.5 or lower and ORP 200-400 mV by adding an acidthereto, so as to reduce chromium contained in the water; and a precipitation separation step in which a neutralizing agent is added to a solutionobtained via the reduction step so as to adjust the solutionto pH 8-9, thereby precipitating and separating, as a hydroxide, the reduced chromium contained in the solution.

Chromium-containing water treatment method

Provided is a method for producing nickel sulfide from an acidic sulfuric acid solution containing nickel, which is capable of suppressing particle diameters of nickel sulfide obtained thereby. The present invention is a method for producing nickel sulfide by causing a sulfurization reaction by blowing a hydrogen sulfide gas into an acidic sulfuric acid solution containing nickel, wherein: nickel sulfide having particle diameters of 5-20 &#x3bc;m and serving as seed crystals is added into an acidic sulfuric acid solution having a nickel concentration of 0.5-5.0 g/L in an amount of 40-500% by mass relative to the amount of nickel contained in the acidic sulfuric acid solution; and a hydrogen sulfide gas is blown into the acidic sulfuric acid solution, into which the seed crystals have been added, while setting the amount of the hydrogen sulfide gas blown in to be within the range of 0.30-0.85 Nm/kg-Ni.

Method for producing nickel sulfide and hydrometallurgical method for nickel oxide ore

This invention provides a method for shortening operation shutdown time of high pressure acid leach equipment in a hydrometallurgical process, wherein the high pressure acid leach equipment comprises (i) means to transfer an ore slurry into the high pressure acid leach equipment;(ii) means to increase temperature and pressure of an ore slurry before leaching; (iii) means to add sulfuric acid into the high pressure acid leach equipment and to leach the ore slurry to obtain a leached slurry at high temperature under high pressure; (iv) means to adjust the pressure of the leached slurry; and (v) means to discharge the leached from the high pressure acid leach equipment; wherein, upon operation shutdown of the high pressure acid leach equipment, the leached slurry is subjected to self-circulation inside the high pressure acid leach equipment.

Method for shortening operation shutdown time of high pressure acid leach equipment in a hydrometallurgical process

The present invention aims at providing a method for effluent treatment, which enables the separation and recovery of a high-density and high-concentration aluminum sediment from waste water that is discharged in the smelting of a nickel oxide ore and contains aluminum ions. In the present invention, an alkali and an iron-containing solid are added to waste water containing aluminum ions to form a slurry, and the slurry is allowed to stand to perform solid-liquid separation, whereby an aluminum sediment and an effluent is formed.

Method for effluent treatment in smelting of nickel oxide ore

Disclosed is a method for producing an ore slurry that can suppress a rise in the viscosity of the ore slurry and consequently prevent a failure in transporting the slurry, and also to provide a metal refining method utilizing such a slurry producing method. The present invention includes: a pulverizing/classifying step of pulverizing raw material ores and classifying the resulting ores at a predetermined classifying point so that oversized ore particles are removed so as to obtain a coarse ore slurry composed of undersized ore particles; a grain size measuring step of measuring the grain size of the resulting coarse ore slurry; and an ore slurry condensing step of loading the coarse ore slurry to a solid-liquid separation device and separating and removing moisture contained in the coarse ore slurry therefrom so as to condense ore components.

Ore slurry production method and metal refining method

A hydrometallurgical plant for nickel laterite ore extraction having a plurality of treatment facility lines wherein the plant is capable of minimizing a decrease in throughput when line failure occurs and efficiently restoring normal operation status Each line of the treatment facility includes a pretreatment step, a leaching step, a solid-liquid separation step, a neutralization step, a zinc removal step, a sulfurization step and a detoxification step. The lines are coupled by pipelines, each having a valve, installed after the solid-liquid separation step for sending a liquid from the solid-liquid separation step to the neutralization step in each line and/or after the sulfurization step for sending a liquid from the sulfurization step to the detoxification step in each line.

Hydrometallurgical plant of nickel laterite ore and operation method thereof

Provided is a method for producing ferronickel from a nickel sulfide or a mixed sulfide containing nickel and cobalt, obtained by hydrometallurgy of nickel oxide ore or obtained from scraps or products in process. The method for producing a ferronickel raw material is to form the ferronickel raw material from a nickel sulfide or a mixed sulfide containing nickel sulfide and cobalt sulfide, wherein treatments are performed through the following steps: (1) redissolution step, (2) deferrization step, (3) solvent extraction step, (4) hydroxylation step, (5) roasting step, and (6) washing and calcining step.

Method for producing raw material for ferronickel smelting from low grade nickel oxide ore

A production process of a sulfide containing nickel and cobalt by adding a sulfurizing agent under pressurization into an aqueous solution of sulfuric acid containing nickel and cobalt, which is capable of recovering nickel and cobalt as a sulfide in high yield, as well as enhancing the utilization efficiency of hydrogen sulfide gas. A production process of a sulfide containing nickel and cobalt by adding a sulfurizing agent under pressurization into an aqueous solution of sulfuric acid containing nickel and cobalt, characterized by supplying, as the above sulfurizing agent, hydrogen sulfide gas into the vapor phase of inside of a reactor, as a major sulfurizing agent, as well as, by supplying an aqueous solution containing a sodium hydrosulfide, which is recovered by absorbing unreacted hydrogen sulfide gas, which is discharged from inside of the reactor in producing the above sulfide, with an aqueous solution of sodium hydroxide, into the liquid phase.

Production process of sulfide containing nickel and cobalt

A hydrometallurgical process for a nickel oxide ore comprising obtaining an aqueous solution of crude nickel sulfate by high pressure acid leaching of a nickel oxide ore; obtaining a zinc free final solution by sulfurization of the solution; obtaining a waste solution; and scrubbing hydrogen sulfide gas from an exhaust gas. The process is characterized by at least one of the following operations: Adjusting the total volume (m) of a sulfurization reactor to a ratio of 0.2-0.9 (m/kg/h) relative to the input mass (kg/h) of the nickel to be introduced to the reactor; and/or subjecting the waste solution and the exhaust gas to countercurrent contact, then introducing the exhaust gas back to the scrubber and charging the waste solution from the scrubber into the sulfurization reactor.

Hydrometallurgical process for a nickel oxide ore

The separation method for zinc sulfide, in the hydrometallurgical process by a High Pressure Acid Leach for nickel oxide ore comprising leaching and solid/liquid separation step, neutralization step, zinc removal step, and nickel recovery step, which can inhibit clogging of a filter cloth and reduce a frequency of washing operation and replacement operation of a filter cloth by improving filtration performance of zinc sulfide, and inhibit decrease of nickel recovery ratio, in the zinc removal step in which zinc sulfide is formed by adding a sulfurizing agent to the neutralization final liquid containing zinc as well as nickel and cobalt and zinc sulfide is separated to obtain a mother liquid for nickel recovery containing nickel and cobalt. The separation method for zinc sulfide of the present invention is characterized in that in the above-described neutralization step, the leach residue is added to the leach liquor, and pH of the neutralization final liquid is adjusted so as to fall to the range from 3.0 to 3.5, and in the zinc removal step, the suspended solid comprising the neutralized precipitate and the leaching reside are kept remained in said neutralization final liquid so that turbidity thereof falls in the range from 100 to 400 NTU.

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Tokyo, Japan

Keisuke Shibayama