Sumitomo Metal Mining Company, Ltd.

Yasumasa Kan

Hideki Sasaki

Masaki Imamura

Go Ohara

Hiroyuki Mitsui

Hidetoshi Watanabe

Yoshitomo Ozaki

Tatsuya Higaki

Yasumasa Hattori

Hirofumi Shouji

Manabu Enomoto

Provided is a production method for refining iron oxide (hematite), which has such a low sulfur content as to be used as a raw material for ironmaking from a leach residue containing iron oxide, the leach residue being produced by a high pressure acid leach (HPAL) process and being a raw material that can be cheaply and stably procured. In the method of producing (high purity) hematite for ironmaking by a process of adding an oxidant and sulfuric acid to nickel oxide ore and then leaching nickel, a leach residue obtained after the leaching of nickel is heated to 600&#xb0; C. or more, and preferably 800&#xb0; C. or more and 1400&#xb0; C. or less.

Production method for hematite for iron production

There is provided a method for producing (high purity) hematite for ironmaking, in a process where a mineral acid and an oxidizing agent are added to an ore containing iron and a valuable metal and then the valuable metal is leached under high temperatures and high pressures, comprises the steps of: (1) a high pressure leach step; (2) a preliminary neutralization step; (3) a solid-liquid separation step 1; (4) a neutralization step 1; (5) a neutralization step 2; (6) a solid-liquid separation step 3; (7) seed crystal addition treatment; (8) a solid-liquid separation step 2; and (9) a firing step.

Method for producing hematite for ironmaking

Proposed is a process for separating a leach residue from which a hematite-containing material that can be used as a raw material for ironmaking can be obtained, and provided is a production process of hematite for ironmaking from the leach residue. The process for producing hematite for ironmaking using, as a raw material, the leach residue in a slurry state obtained from a hydrometallurgical plant for nickel oxide ore utilizing a high pressure acid leach process comprises in sequence: a first step of separating the leach residue in a slurry state into an overflow and an underflow using a wet cyclone; a second step of separating the overflow into a strong magnetic component and a weak magnetic component using a strong-magnetic-field magnetic separator utilizing magnetic force; and a third step of sintering the separated strong magnetic component at a temperature of 1150 to 1350&#xb0; C. to form a sintered body.

Process for producing hemataite for ironmaking

A process is provided for obtaining a hematite-containing material that can be used for ironmaking. The process includes separating a leach residue from a hydrometallurgical refining plant into an overflow and an underflow using a wet cyclone under a condition that the wet cyclone is adjusted to have a setting between 1 &#x3bc;m or less and 2 &#x3bc;m or less as a classification particle size for the overflow. The process then includes separating the overflow into a strong magnetic substance and a weak magnetic substance using a strong-magnetic-field magnetic separator under a condition that magnetic field intensity is 5 to 20 [kGauss]. The process then includes using a superheated steam drying system for adjusting a moisture content of the strong magnetic substance after the separation, to be 10 wt % to 17 wt %.

Process for producing hematite for ironmaking

A method of producing (high-purity) hematite for ironmaking includes adding an oxidant and sulfuric acid to nickel oxide ore and then leaching nickel. The method further includes forming a neutralized residue having a sulfur grade exceeding 1.0% by weight by adding a neutralizing agent to leach slurry and being subjected to solid-liquid separation. The neutralizing agent functions to form plaster by reaction with a free sulfuric acid of surplus acid contained in the leach slurry. The leach slurry is a mixture of a leachate and a leach residue obtained after leaching the nickel. The method then includes heating the neutralized residue at a heating temperature of 600&#xb0; C. or more and 1400&#xb0; C. or less to form hematite having a sulfur grade of 1.0% or less by weight.

Provided is a method for producing hematite for ironmaking, capable of using a conventional Ca-based neutralizing agent and a base rock-derived neutralizing agent other than the Ca-based neutralizing agent. The method is performed by a process of adding a mineral acid and an oxidizing agent to an ore containing iron and a valuable metal and then leaching the valuable metal under high temperature and pressure, and includes (1) a high-pressure acid leaching step, (2) a preliminary neutralization step, (3) a first solid-liquid separation step, (4) a neutralization step, (5) a second neutralization step, (6) a third solid-liquid separation step, (7) a step of adding part of the Fe-enriched slurry as a seed crystal in the neutralization step (4), and (8) a second solid-liquid separation step.

Provided is a hydrometallurgical process of recovering Ni from nickel oxide ore using a high pressure acid leaching, in which abrasion of the facilities caused by an ore slurry is suppressed, the amount of a final neutralized residue is reduced, and impurity components are separated and recovered for recycling. The hydrometallurgical process includes, as steps of the high pressure acid leaching, at least one step selected from step (A): separating and recovering chromite particles in the ore slurry; step (B-1): through leaching step and a solid-liquid separation step, performing neutralization of a leachate obtained after the solid-liquid separation step using a Mg-based alkali such as Mg(OH); and step (B-2): through leaching step and a solid-liquid separation step, performing neutralization of a leachate obtained after the solid-liquid separation step using a Mg-based alkali such as Mg(OH), and then recovering hematite particles.

Hydrometallurgical process for nickel oxide ore

A method is provided for separating a leach residue from which a hematite-containing material capable of being used as a raw material for ironmaking can be obtained. A method also is provided for producing hematite for ironmaking from the leach residue. The method utilizes a leach residue as a raw material, the leach residue being obtained from a hydrometallurgical refining plant where a nickel oxide ore treated by a high pressure acid leach process. The method includes, in sequence: a separation step of separating the leach residue into an overflow and an underflow with a wet cyclone; and another separation step of separating the separated overflow into a strong magnetic substance and a weak magnetic substance using magnetic force, wherein a strong-magnetic-field magnetic separator is used in the another separation step using the magnetic force.

Provided is a method for producing hematite for ironmaking, wherein high purity hematite, which can be used as an iron-making raw material, is cheaply and efficiently recovered from a leach residue containing iron oxide produced by a high pressure acid leach (HPAL) process. This method for producing (high purity) hematite for ironmaking in a process of adding a mineral acid and an oxidant to ore containing iron and valuable metals and then leaching the valuable metals under high pressure and high temperature includes (1) a neutralization step of adding a neutralizer to a leachate obtained under high pressure and high temperature to form a leach slurry, (2) a solid-liquid separation step of separating the leach slurry obtained in the neutralization step (1) into a leach residue and the leachate, and (3) a classification step of classifying the leach residue into the hematite and gangue components.

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Tokyo, Japan

Yasumasa Kan