Pneumatic ore charging

Patent metadata

Field	Value
Publication number	US-2016348199-A1
Application number	US-201515117374-A
Country	US
Kind code	A1
Filing date	Jan 27, 2015
Priority date	Feb 10, 2014
Publication date	Dec 1, 2016
Grant date	—

Abstract

A method for reducing metal oxide containing charge materials ( 1 ): reducing the metal oxide containing charge materials ( 1 ) in at least two fluidized bed units (RA,RE) by means of a reduction gas ( 2 ), wherein at least some of the resulting off-gas ( 3 ) is recycled and wherein the metal oxide containing charge materials ( 1 ) are conveyed into the fluidized bed unit RE by a propellant gas. Also, apparatus for carrying out the method according to the invention is disclosed.

First claim

1 . A method for reducing metal oxide containing charge materials, comprising:
reducing the metal oxide containing charge materials by a reduction gas in at least a first and a second fluidized bed units, and flowing the reduction gas through the fluidized bed units countercurrently to the metal oxide containing charge materials; removing as off-gas ( 3 ) from the first fluidized bed unit the reduction gas used during reduction of the metal oxide containing charge materials in the at least two fluidized bed units; compressing at least some of the off-gas in at least one recycle gas compressor to produce hot recycle gas, and then cooling the hot recycle gas in at least one aftercooler to produce cold recycle gas; at least partially removing CO 2 from the cold recycle gas to produce product gas; admixing the product gas with the reduction gas, optionally after pre-heating in a heating device; conveying the metal oxide containing charge materials by a propellant gas from at least one delivery tank by a pipe line into the first fluidized bed unit, wherein the propellant gas comprises at least some of the hot recycle gas; the hot recycle gas has a lower temperature limit of 70° C. and an upper temperature limit of 150° C.; the product gas has a dew point of below −20° C.; and the pressure of the hot recycle gas is at least 4.5 barg.

2 . The method as claimed in claim 1 , wherein the metal oxide containing charge materials are selected from the group consisting of oxides of each of iron, nickel, manganese, copper, lead or cobalt or mixtures thereof.

3 . The method as claimed in claim 1 , wherein the propellant gas comprises the hot recycle gas.

4 . The method as claimed in claim 1 , wherein the propellant gas comprises at least some of the product gas.

5 - 6 . (canceled)

7 . The method as claimed in claim 1 , further comprising pre-heating and/or drying the metal oxide containing charge materials before conveying the materials into the first fluidized bed unit by means of the propellant gas.

8 . The method as claimed in claim 1 , wherein upon a shortfall of the hot recycle gas, compensating for the shortfall by introducing nitrogen in order to ensure the conveying of the metal oxide containing charge materials into the first fluidized bed unit.

9 . (canceled)

10 . The method as claimed in claim 1 , further comprising the pressure of the hot recycle gas is between 0.5 bar and 3.0 bar, above the pressure in the first fluidized bed unit depending on the delivery head.

11 . The method as claimed in claim 1 , further comprising the pipe line comprises a double-wall tube, and a space between the two tube walls is filled with a gas, wherein the pressure of the gas is monitored to detect leaks.

12 . The method as claimed in claim 1 , further comprising a flow-based leak detection device is present in at least one wall of the pipe line and measures to detect a leak.

13 . The method as claimed in claim 1 , further comprising the pipe line has an inner wall which is lined with a ceramic compound, to avoid wear.

14 . The method as claimed in claim 1 , further comprising at least one additional fluidized bed unit, flooding the additional fluidized bed unit by reduction gas introduced into the second fluidized bed unit and flowing the reduction gas through the three fluidized bed units countercurrently to the metal oxide containing charge materials.

15 . The method as claimed in claim 1 , further comprising the reduction gas comes from a melter gasifier, a coal gasification plant, a coking plant, a steam reformer or a CO 2 reformer.

16 . The method as claimed in claim 15 , further comprising if the reduction gas comes from the coal gasification plant or from the coking plant, expanding or compressing and rendered largely CO 2 - free and/or H 2 O-free and pre-heated before being fed to the at least first and second fluidized bed units.

17 . An apparatus for carrying out the method as claimed in claim 1 , the apparatus comprising:
at least a first and a second fluidized bed units for reducing metal oxide containing charge materials by means of a reduction gas; the first fluidized bed unit has an off-gas pipe for extracting an off-gas and the second fluidized bed unit has a reduction gas feed pipe for supplying the reduction gas; a reduction gas pipe coming out of the second fluidized bed unit and leading into the first fluidized bed unit, and a material conveying pipe coming out of the first fluidized bed unit and leading into the second fluidized bed unit; a recycle gas pipe ( 16 ) branching out from the off-gas pipe and leading into the reduction gas feed pipe; at least one recycle gas compressor, at least one aftercooler, a CO 2 removal device and optionally a heating device are, disposed one after the other, in the recycle gas pipe; a delivery tank for storing the metal oxide containing charge materials and having a pneumatic conveying device; a first propellant gas pipe branching off between the last recycle gas compressor and the aftercooler and leading into the pneumatic conveying device and/or the delivery tank, wherein the pneumatic conveying device is connected to the fluidized bed unit by a pipe line for pneumatically conveying the metal oxide containing charge materials ( 1 ) into the fluidized bed unit; a second propellant gas pipe branching out from the recycle gas pipe between the CO 2 removal device and the second fluidized bed unit and leading into the first propellant gas pipe and/or into the delivery tank and/or into the pneumatic conveying device; and at least one nitrogen pipe leading into the pneumatic conveying device and/or into the delivery tank and/or into the first propellant gas pipe and/or into the second propellant gas pipe.

18 - 19 . (canceled)

20 . The apparatus as claimed in claim 17 , further comprising the pipe line comprises a double-wall tube having a pressure-based leak detection device.

21 . The apparatus as claimed in claim 17 , further comprising a flow-based leak detection device in at least one wall of the pipe line.

22 . The apparatus as claimed in claim 17 , further comprising a ceramic compound applied to an inner wall of the pipe line for protection of the inner wall from wear.

23 . The apparatus as claimed in claim 17 , further comprising at least one additional fluidized bed unit via which the reduction gas pipe and the material conveying pipe are run.

24 . The apparatus as claimed in claim 17 , further comprising the reduction gas feed pipe comes from a melter gasifier, a coal gasification plant, a coking plant, a steam reformer or a CO 2 reformer.

25 . The apparatus as claimed in claim 24 , if the reduction gas feed pipe comes from the coal gasification plant or the coking plant, an expansion turbine or a compressor and devices for removing CO 2 and/or water are disposed in the reduction gas feed pipe.

Assignees

• Primetals Technologies Austria GmbH

Inventors

• Millner Robert
• Plaul Jan-Friedemann
• Rein Norbert

Classifications

• F27D3/18

  Charging particulate material using a fluid carrier · CPC title

• C21B13/006

  Starting from ores containing non ferrous metallic oxides · CPC title

• C21B13/0033 Primary

  In fluidised bed furnaces or apparatus containing a dispersion of the material · CPC title

• F27D2003/185

  Conveying particles in a conduct using a fluid · CPC title

• C21B2100/66

  Heat exchange · CPC title