Hydrometallurgical process for nickel oxide ore

Abstract

Provided is a hydrometallurgical process for nickel oxide ore for recovering nickel and cobalt using a high pressure acid leach process, the process achieving simplification and durability improvement of production facilities, achieving cost reduction and suppression of environmental risk by the compression of the capacity of a tailings dam for storing wastes, and being capable of recycling and effectively utilizing the wastes as a resource. The hydrometallurgical process for nickel oxide ore for recovering nickel and cobalt using a high pressure acid leach process includes an ore processing step, a leaching step, a solid-liquid separation step, a neutralization step, a zinc removal step, a sulfurization step, and a final neutralization step, and further includes step (A), or further includes step (A) and, step (B-1) and / or step (B-2) after step (A).

Description

[0001]The present application is a divisional application of U.S. patent application Ser. No. 15 / 304,898, filed Oct. 18, 2016, the contents of which are hereby incorporated by reference in their entirety.BACKGROUND1. Field of the Invention[0002]The present invention relates to a hydrometallurgical process for nickel oxide ore, specifically relates to a hydrometallurgical process for nickel oxide ore for recovering nickel and cobalt from nickel oxide ore using a high pressure acid leach process including an ore processing step, a leaching step, a solid-liquid separation step, a neutralization step, a zinc removal step, a sulfurization step, and a final neutralization step, in which problems are solved by suppressing the wear, caused by an ore slurry produced from the ore processing step, of facilities such as conveyance piping and a pump for conveying the ore slurry and improving the durability of the facilities to thereby reduce the amount of a final neutralized residue produced fro...

AI Technical Summary

Benefits of technology

[0066]The hydrometallurgical process for nickel oxide ore of the present invention produces an industrially remarkable effect because conventional problems can be solved as shown below by adopting step (A) and step (B) in a hydrometallurgical process for recovering nickel and cobalt from nickel oxide ore using a high pressure acid leach process including an ore processing step, a leaching step, a solid-liquid separation step, a neutralization step, a zinc removal step, a sulfurization step, and a final neutralization step.

[0067]By adopting step (A) in the present invention, particles containing chromite in the ore slurry produced from the ore processing step can be separated and recovered to thereby significantly suppress the wear of facilities such as piping and a pump during the conveyance of the ore slurry.

[0068]Further, since chromite is separated before the hydrometallurgy, a reduction in the amount of the leach residue can be expected, and the amount of a final neutralized residue can also be reduced. Furthermore, if the separated chromite is concentrated, the concentrate can also be effectively used as a resource.

[0069]By adopting step (B) in the present invention, hematite in the leach residue produced from the solid-liquid separation step is separated and recovered to thereby achieve a reduction in the amount of a final neutralized residue produced from the final neutralization step, thereby capable of compressing the capacity of a tailings dam for storing a leach residue, a neutralized precipitate, and the like to be discarded to thereby reduce cost and environmental risk, and the hematite separated and recovered can also be effectively used as an iron resource.

Problems solved by technology

In recent years, raw material cost for metal smelting has significantly increased with the further progress of oligopolization of mining rights for mineral resources, such as coal, iron, copper, nickel, cobalt, chromium, and manganese.

Therefore, also in metal smelting, technical development has been made, as a measure for cost reduction, for using a low-grade raw material which has not been used since it is disadvantageous in terms of cost.

However, there have been problems in that the two-stage leaching has increased the number of equipment to increase cost and labor, and a large amount of dilute solution produced in the washing of the leach residue has required cost.

However, the practical plant using this method will have the following problems.

A first problem is the wear of facilities, which is required to be suppressed.

The wear of the materials of facilities is significantly accelerated by the conveyed slurry, and especially the frequency of maintenance of the facilities such as piping and pumps in the leaching step is high, which greatly causes an increase in maintenance cost and a reduction in the rate of plant operation.

A second problem is the amount of the final neutralized residue, which is required to be reduced.

Therefore, the final neutralized residue cannot be recycled, and the construction and the maintenance of the tailings dam have been a heavy cost burden.

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