Starting a smelting process

Patent metadata

Field	Value
Publication number	US-9458518-B2
Application number	US-201214363262-A
Country	US
Kind code	B2
Filing date	Dec 6, 2012
Priority date	Dec 6, 2011
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

A method of starting a molten-bath based melting process includes establishing a sufficiently large and stable “hot zone” for ignition of oxygen and coal in a main chamber of a smelting vessel by independent means, i.e. independently of and before supplying cold oxygen and coal into the main chamber.

First claim

The invention claimed is:

1. A method of starting a molten-bath based process for smelting a metalliferous feed material to form a molten metal in a smelting apparatus, with the apparatus including a smelting vessel that includes a main chamber that contains frozen materials and a bath of molten metal, and with the method including the steps of:
(a) inserting an external ignition source into the main chamber of the smelting vessel to form a hot zone in the main chamber;
(b) commencing supplying a cold oxygen-containing gas into the main chamber and igniting combustible material in the main chamber,
(c) commencing supplying a carbonaceous material into the main chamber and increasing the temperature in the main chamber and melting the frozen materials in the main chamber, and
(d) commencing supplying metalliferous material into the main chamber and smelting the metalliferous material and producing molten metal in the main chamber.

2. The method defined in claim 1 includes supplying a combustible material to the main chamber prior to step (a) of inserting the external ignition source into the main chamber.

3. The method defined in claim 2 includes supplying the combustible material into the main chamber by manually inserting the combustible material through an opening in the main chamber.

4. The method defined in claim 1 includes supplying a combustible material to the main chamber after step (a) of inserting the external ignition source into the main chamber and prior to step (b) of commencing supplying the cold oxygen-containing gas into the main chamber and igniting the combustible material in the main chamber.

5. The method defined in claim 1 includes commencing supplying slag or slag forming materials into the main chamber and forming a slag on the molten metal after step (c) and before step (d).

6. The method defined in claim 1 wherein the ignition source is adapted to operate for a time-duration of at least 3 minutes.

7. The method defined in claim 1 wherein the ignition source is selected on the basis that it does not require gaseous oxygen in the main chamber in order to stay alight.

8. The method defined in claim 1 wherein the ignition source for step (a) carries its own oxygen such that it burns regardless of whether it is in air, oxygen or nitrogen.

9. The method defined in claim 1 wherein the ignition source for step (a) is a magnesium-based flare.

10. The method defined in claim 1 includes verifying that the external ignition source is alight in the main chamber after inserting the external ignition source into the main chamber in step (a).

11. The method defined in claim 10 wherein the step of verifying the ignition source is alight in the main chamber is via direct observation or via a camera mounted within an opening in the smelting vessel.

12. The method defined in claim 1 wherein step (b) of commencing supplying the cold oxygen-containing gas and igniting combustible material in the main chamber includes commencing supplying oxygen into the main chamber and igniting combustible material in the main chamber.

13. The method defined in claim 12 wherein step (b) of commencing supplying the cold oxygen-containing gas and igniting combustible material in the main chamber includes commencing supplying technical grade oxygen at a feed temperature below 800° C. to the main chamber and igniting combustible material in the main chamber.

14. The method defined in claim 12 wherein the flow of cold oxygen-containing gas is 10-30% of normal oxygen flow for the molten bath-based smelting process.

15. The method defined in claim 14 includes verifying ignition of combustible material after step (b) of igniting combustible material in the main chamber.

16. The method defined in claim 1 wherein the step of verifying ignition is via direct observation or via a suitable camera that material is burning in the main chamber.

17. The method defined in claim 1 wherein step (c) of commencing supplying the carbonaceous material includes supplying the carbonaceous material into the main chamber at a feed temperature below 150° C.

18. The method defined in claim 1 wherein step (c) includes verifying that carbon dioxide generation in the main chamber is ongoing via an on-line gas analysis system.

19. The method defined in claim 1 wherein step (d) includes ramping up supplying the oxygen-containing gas and the carbonaceous material supplied in steps (b) and (c) respectively of the method or supplying increasing amounts of other oxygen-containing gas and carbonaceous material into the main chamber.

20. The method defined in claim 1 wherein step (d) includes ramping up supplying the metalliferous material into the main chamber.

21. The method defined in claim 1 wherein the molten bath-based smelting process includes the steps of:
(a) supplying the solid carbonaceous material and the metalliferous material which is solid or molten into the molten bath and generating reaction gas and smelting metalliferous material and producing molten metal in the bath;
(b) supplying the oxygen-containing gas into the main chamber for above-bath combustion of reaction gas in order to generate heat for smelting the metalliferous material to molten metal; and
(c) producing significant upward movement of molten material from the bath by gas upwelling in order to create heat-carrying droplets and splashes of molten material which are heated when projected into a combustion region in the top space of the main chamber and thereafter fall back into the bath, whereby the droplets and splashes carry heat downwards into the bath where it is used for smelting of the metalliferous material.

Assignees

• Tech Resources Pty Ltd
• Tech Resources Pty Ltd

Inventors

• Pilote Jacques
• Dry Rodney James
• Meijer Hendrikus Koenraad Albertus

Classifications

• C21B5/001

  Injecting additional fuel or reducing agents · CPC title

• C22B5/10

  by solid carbonaceous reducing agents · CPC title

• C21C5/4606

  Lances or injectors · CPC title

• C21B13/0006

  obtaining iron or steel in a molten state · CPC title

• C21B13/00

  Making spongy iron or liquid steel, by direct processes · CPC title