Method for smelting oxide ore

Patent metadata

Field	Value
Publication number	US-2019144971-A1
Application number	US-201716093339-A
Country	US
Kind code	A1
Filing date	Apr 19, 2017
Priority date	Apr 22, 2016
Publication date	May 16, 2019
Grant date	—

Abstract

Provided is a smelting method for producing metal by reducing a mixture that includes an oxide ore such as nickel oxide ore, wherein it is possible to improve productivity by raising the metal recovery rate as well as to inexpensively and efficiently produce high-quality metal. The present invention is a smelting method in which: an oxide ore and a carbonaceous reducing agent are mixed; the resulting mixture is heated and subjected to a reduction treatment; and metal and slag, which are reduction products, are obtained, wherein the reduction treatment is carried out in a state in which one or more surface deposits selected from carbonaceous reducing agents, metal oxides, and oxidation inhibitors are deposited on the surface of the mixture.

First claim

1 . An oxide ore smelting method for obtaining a metal of a reduction product and slag by mixing an oxide ore and a carbonaceous reducing agent, heating the mixture obtained, and subjecting the mixture to a reduction treatment, wherein
the reduction treatment is performed in a state in which one or more kinds of surface deposits selected from a carbonaceous reducing agent, a metal oxide, and an oxidation inhibitor are deposited on a surface of the mixture.

2 . The oxide ore smelting method according to claim 1 , wherein the oxide ore is nickel oxide ore, and
at least the carbonaceous reducing agent is used as the surface deposit and an amount of the carbonaceous reducing agent to be deposited on the surface of the mixture is set to a proportion of 0.1% by mass or more and 20.0% by mass or less when an amount of a carbonaceous reducing agent required for reducing nickel oxide and iron oxide contained in the mixture without excess or deficiency is taken as 100% by mass.

3 . The oxide ore smelting method according to claim 2 , wherein an amount of a carbonaceous reducing agent present inside the mixture together with the oxide ore is set to a proportion of 40.0% by mass or less when an amount of a carbonaceous reducing agent required for reducing nickel oxide and iron oxide contained in the mixture without excess or deficiency is taken as 100% by mass.

4 . The oxide ore smelting method according to claim 1 , wherein at least the metal oxide is used as the surface deposit, and
the metal oxide is nickel oxide and/or iron oxide.

5 . The oxide ore smelting method according to claim 4 , wherein the oxide ore is nickel oxide ore, and
the metal oxide is deposited on the surface of the mixture so that an amount of a metal contained in the metal oxide is a proportion of 0.03% by mass or more and 8.0% by mass or less when a total amount of metals of nickel and iron contained in the mixture is taken as 100% by mass.

6 . The oxide ore smelting method according to claim 5 , wherein an amount of a carbonaceous reducing agent present inside the mixture together with the oxide ore is set to a proportion of 12.0% by mass or more and 35.0% by mass or less when an amount of a carbonaceous reducing agent required for reducing nickel oxide and iron oxide contained in the mixture without excess or deficiency is taken as 100% by mass.

7 . The oxide ore smelting method according to claim 6 , wherein the metal oxide is deposited on the surface of the mixture so that an amount of a metal contained in the metal oxide is a proportion of 0.1% by mass or more and 2.0% by mass or less when the total amount of metals of nickel and iron contained in the mixture is taken as 100% by mass.

8 . The oxide ore smelting method according to claim 1 , wherein at least the oxidation inhibitor is used as the surface deposit, and
the oxidation inhibitor is an oxide mixture having an oxide content of 90% by mass or more.

9 . The oxide ore smelting method according to claim 1 , wherein at least the oxidation inhibitor is used as the surface deposit, and
the oxidation inhibitor is an oxidation inhibiting mixture containing an oxide mixture having an oxide content of 90% by mass or more and a carbonaceous reductant.

10 . The oxide ore smelting method according to claim 9 , wherein the carbonaceous reductant contained in the oxidation inhibiting mixture is coal and/or coke.

11 . The oxide ore smelting method according to claim 8 , wherein the surface deposit is put on an upper surface of the mixture and the reduction treatment is performed.

12 . The oxide ore smelting method according to claim 8 , wherein the mixture is surrounded with the surface deposit and the reduction treatment is performed.

13 . The oxide ore smelting method according to claim 8 , wherein ash of the carbonaceous reducing agent is at least partially used as the oxidation inhibitor.

14 . The oxide ore smelting method according to claim 8 , wherein one or more kinds selected from coal ash, charcoal ash, and bamboo charcoal ash are at least partially used as the oxidation inhibitor.

15 . The oxide ore smelting method according to claim 8 , wherein one or more kinds selected from alumina, alumina cement, magnesia, magnesia cement, zirconia, zirconia cement and mullite are at least partially used as the oxidation inhibitor.

16 . The oxide ore smelting method according to claim 1 , wherein a treatment is performed in a state in which the mixture is charged into a reducing furnace having a carbonaceous reducing agent spread on a hearth in advance and the mixture is placed on the carbonaceous reducing agent in the reduction treatment.

17 . The oxide ore smelting method according to claim 1 , wherein a reducing temperature in the reduction treatment is set to 1200° C. or more and 1450° C. or less.

18 . The oxide ore smelting method according to claim 9 , wherein the surface deposit is put on an upper surface of the mixture and the reduction treatment is performed.

19 . The oxide ore smelting method according to claim 2 , wherein a treatment is performed in a state in which the mixture is charged into a reducing furnace having a carbonaceous reducing agent spread on a hearth in advance and the mixture is placed on the carbonaceous reducing agent in the reduction treatment.

20 . The oxide ore smelting method according to claim 2 , wherein a reducing temperature in the reduction treatment is set to 1200° C. or more and 1450° C. or less.

Assignees

• Sumitomo Metal Mining Co

Inventors

• Iseki Takashi
• Goda Yukihiro
• Kobayashi Jun-Ichi
• Okada Shuji

Classifications

• C21B13/105

  Rotary hearth-type furnaces · CPC title

• C21B13/006

  Starting from ores containing non ferrous metallic oxides · CPC title

• C21B13/10

  in hearth-type furnaces · CPC title

• C21B13/0053 Primary

  On a massing grate · CPC title

• C22B1/244

  organic · CPC title