Method for smelting nickel oxide ore

Patent metadata

Field	Value
Publication number	US-2017342514-A1
Application number	US-201515537965-A
Country	US
Kind code	A1
Filing date	Sep 15, 2015
Priority date	Dec 24, 2014
Publication date	Nov 30, 2017
Grant date	—

Abstract

Provided is a smelting method capable of effectively promoting a reduction reaction on pellets formed using nickel oxide ore as starting material to obtain a ferronickel alloy with a high nickel grade of at least 4%. The present invention is a method for smelting nickel oxide ore wherein ferronickel alloy with a nickel grade of at least 4%, the method comprising a pellet-producing step S 1 for producing pellets from nickel oxide ore, and a reducing step S 2 for reduction-heating of the obtained pellets in a smelting furnace. In the pellet-producing step S1, the pellets are produced by mixing nickel oxide ore with a specified amount of a carbonaceous reducing agent as starting materials. In the reducing step S 2 , the produced pellets are charged in a smelting furnace in which a carbonaceous reducing agent (furnace bottom carbonaceous reducing agent) has been spread over the entire furnace bottom and reduction-heating is performed.

First claim

1 . A method for smelting nickel oxide ore, in which a pellet is formed from the nickel oxide ore, and the pellet is heat-reduced to obtain an iron-nickel alloy with a nickel grade of 4% or more, the method comprising:
a pellet production step for producing a pellet from the nickel oxide ore, and a reduction step for heat-reducing the resulting pellet in a smelting furnace, the pellet production step comprising mixing the nickel oxide ore with at least a carbonaceous reducing agent, the mixed amount of the carbonaceous reducing agent being adjusted so that the amount of carbon is 40% or less when the total combined value of a chemical equivalent required for reducing nickel oxide contained in the resulting pellet into nickel metal and a chemical equivalent required for reducing ferric oxide contained in said pellet into ferrous oxide and then further reducing a portion of the ferrous oxide into iron metal until the mass ratio of iron and nickel is 80:20 in an iron-nickel alloy to be obtained is taken as 100%, and agglomerating the resulting mixture to form a pellet, and the reduction step comprising pre-covering the furnace floor of the smelting furnace with a furnace floor carbonaceous reducing agent before charging the resulting pellet into the smelting furnace, and performing reduction heat treatment with the pellet loaded onto the furnace floor carbonaceous reducing agent.

2 . The method for smelting nickel oxide ore according to claim 1 , wherein
the reduction step comprises heat-reducing the pellet loaded onto the furnace floor carbonaceous reducing agent at a heating temperature of 1350° C. or more and 1550° C. or less.

3 . The method for smelting nickel oxide ore according to claim 1 , wherein
the temperature when the pellet is charged into the smelting furnace is 600° C. or less.

Assignees

• Sumitomo Metal Mining Co

Inventors

• Takahashi Junichi
• Inoue Taku
• Okada Shuuji

Classifications

• C21B13/10 Primary

  in hearth-type furnaces · CPC title

• C22C1/023

  Alloys based on nickel · CPC title

• C21B13/08

  in rotary furnaces · CPC title

• C22B23/023

  with formation of ferro-nickel or ferro-cobalt · CPC title

• C21B13/004

  in a continuous way by reduction from ores · CPC title