Electrolytic smelting system

Patent metadata

Field	Value
Publication number	US-12305245-B2
Application number	US-202017618672-A
Country	US
Kind code	B2
Filing date	Jan 23, 2020
Priority date	Jun 21, 2019
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

An electrolytic smelting system includes: an electrolytic smelting furnace including a furnace body to which a molten ore is introduced, a cathode substrate which is installed on a bottom portion in the furnace body, and an anode substrate which is positioned above the cathode substrate in the furnace body; an inert gas circulation unit including a circulation line to recover an inert gas supplied into the electrolytic smelting furnace together with oxygen and supply the inert gas to the molten ore; and an oxygen-removing unit which is installed in the circulation line and which removes oxygen from the circulation line.

First claim

The invention claimed is:

1. An electrolytic smelting system comprising: an electrolytic smelting furnace including a furnace body to which a molten ore is introduced, a cathode substrate which is installed on a bottom portion in the furnace body, and an anode substrate which is positioned above the cathode substrate in the furnace body; an inert gas circulation unit including a circulation line configured to supply inert gas to the molten ore and to recover oxygen generated on an anode substrate side together with the inert gas as a mixed gas; and an oxygen-removing unit which is installed in the circulation line and configured to remove the oxygen from the circulation line, wherein the oxygen-removing unit is configured to remove the oxygen from the mixed gas of the inert gas and the oxygen recovered by the inert gas circulation unit, and is configured to reuse the inert gas, and the oxygen-removing unit includes a cell stack having a base pipe through which the inert gas and the oxygen are flowed and a fuel cell which is installed on an outer peripheral surface of the base pipe and which allows the oxygen in the base pipe to permeate to an outside of the base pipe in response to an applied voltage.

2. The electrolytic smelting system according to claim 1 , further comprising:
a temperature control unit which is installed on an upstream side of the oxygen-removing unit in the circulation line and which is configured to control the temperatures of the inert gas and the oxygen flowing through the circulation line to an operating temperature of the fuel cell.

3. The electrolytic smelting system according to claim 2 , wherein the temperature control unit is configured to exchange heat between a relatively high-temperature inert gas and oxygen flowing into the oxygen-removing unit and a relatively low-temperature inert gas flowing out of the oxygen-removing unit.

4. The electrolytic smelting system according to claim 1 , wherein a plurality of through-holes are formed in the anode substrate so as to penetrate the anode substrate in a vertical direction, and
wherein the circulation line is connected to the plurality of through-holes.

5. The electrolytic smelting system according to claim 1 , further comprising:
a preheating unit which is configured to preheat the molten ore supplied to the furnace body; and
a mixing unit which is configured to generate a mixed gas by mixing the oxygen removed from the circulation line in the oxygen-removing unit and the inert gas extracted from a downstream side of the oxygen-removing unit in the circulation line, and passed through an inert gas extraction line and supply the mixed gas to the preheating unit.

6. The electrolytic smelting system according to claim 1 , further comprising:
a preheating unit which is configured to preheat the molten ore supplied to the furnace body,
wherein the oxygen-removing unit includes a first oxygen-removing unit which is configured to generate a mixed gas of the inert gas and the oxygen having a predetermined value of an oxygen partial pressure by removing some of the oxygen from the circulation line by applying a predetermined first voltage and supplying the mixed gas through an injection line to the preheating unit and a second oxygen-removing unit which is configured to remove the oxygen from a residual component of the mixed gas supplied from the first oxygen-removing unit by applying a second voltage lower than the first voltage.

7. The electrolytic smelting system according to claim 5 , wherein the preheating unit includes a heating tank which stores the molten ore and a nozzle which is positioned in the heating tank and supplies the mixed gas into the molten ore.

8. The electrolytic smelting system according to claim 1 , wherein the oxygen-removing unit further includes a branch pipe which is branched at a portion corresponding to a middle position of the base pipe in an extension direction thereof and supplies a mixed gas to the preheating unit, wherein an oxygen partial pressure in the base pipe at the middle position has a predetermined value.

9. The electrolytic smelting system according to claim 5 , further comprising:
a sulfur recovery device which is installed on a downstream side of the preheating unit and which is configured to recover a sulfur content contained in the mixed gas flowing from the preheating unit to generate a desulfurized mixed gas; and
a first extraction line which supplies the desulfurized mixed gas from the sulfur recovery device to the mixing unit.

10. The electrolytic smelting system according to claim 5 , further comprising:
a sulfur recovery device which is installed on a downstream side of the preheating unit and which is configured to recover a sulfur content contained in the mixed gas flowing from the preheating unit to generate a desulfurized mixed gas; and
a second extraction line which supplies the desulfurized mixed gas from the sulfur recovery device to the oxygen-removing unit.

11. The electrolytic smelting system according to claim 9 , further comprising:
an oxygen addition line which supplies the oxygen removed in the oxygen-removing unit to the mixed gas flowing from the preheating unit toward the sulfur recovery device.

12. The electrolytic smelting system according to claim 6 , wherein the preheating unit includes a heating tank which stores the molten ore and a nozzle which is positioned in the heating tank and supplies the mixed gas into the molten ore.

13. The electrolytic smelting system according to claim 6 , further comprising:
a sulfur recovery device which is installed on a downstream side of the preheating unit and which is configured to recover a sulfur content contained in the mixed gas flowing from the preheating unit to generate a desulfurized mixed gas; and
a second extraction line which supplies the desulfurized mixed gas from the sulfur recovery device to the oxygen-removing unit.

14. The electrolytic smelting system according to claim 13 , further comprising:
an oxygen addition line which supplies a part of the oxygen removed in the oxygen-removing unit to the mixed gas flowing from the preheating unit toward the sulfur recovery device.

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Nakano Takashi
• Koshiro Ikumasa

Classifications

• C22B4/08

  Apparatus ({C22B4/005 takes precedence; } electric heating elements H05B) · CPC title

• C22B9/20

  Arc remelting · CPC title

• C25C7/06 Primary

  Operating or servicing · CPC title

• C25C3/34

  of metals not provided for in groups C25C3/02 - C25C3/32 · CPC title

• B01D2257/104

  Oxygen · CPC title