Desulfurization of gases in the production of pig iron

Patent metadata

Field	Value
Publication number	US-2016168652-A1
Application number	US-201414902756-A
Country	US
Kind code	A1
Filing date	Feb 6, 2014
Priority date	Jul 1, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

A process for producing liquid pig iron ( 1 ), in which charge materials ( 2 ) containing iron oxide are reduced by a reducing gas ( 5 ) in a first reduction plant ( 4 ) to form a partially reduced first iron product ( 3 ) and are melted in a fusion gasifier ( 11 ) to form the liquid pig iron ( 1 ). The spent reducing gas ( 5 ) is introduced as export gas ( 6 ) into a second reduction plant ( 7 ), wherein a sulfur-containing gas ( 13 ) is introduced together with an oxygen-containing gas ( 9 ) and/or together with dust ( 16 ) into the fusion gasifier ( 11 ) and/or into the reducing gas line ( 12 ). Also, a device for carrying out the process. It is therefore possible for sulfur-containing gas ( 13 ) to be used for production of liquid pig iron ( 1 ), or DRI, with a simultaneous increase in productivity, without damaging the environment or adversely affecting the quality of the liquid pig iron ( 1 ) or of the DRI.

First claim

1 . A process for producing liquid pig iron, the process comprising:
reducing iron-oxide containing charge materials to produce a part-reduced first iron product in a first reduction unit, the reducing being by means of a reducing gas and then drawing off the reducing gas spent in the reduction as export gas; removing CO 2 from the export gas and then introducing the export gas into at least one second reduction unit for producing a part-reduced second iron product; introducing the part-reduced first iron product, an oxygen-containing gas, and carbon carriers into a melter gasifier; in the melter gasifier, gasifying the carbon carriers with the oxygen-containing gas and melting the part-reduced first iron product to produce the liquid pig iron with formation of the reducing gas; introducing at least a portion of the reducing gas into the first reduction unit by a reducing-gas line; jetting or introducing a sulfur-containing coke-oven gas, a sulfur-containing natural gas, or a mixture of the sulfur-containing natural gas and the coke-oven gas together with the oxygen-containing gas and optionally together with fine coal into the melter gasifier by oxygen nozzles; and/or together with dust and the oxygen-containing gas into the melter gasifier by dust burners ( 17 ) and/or together with the oxygen-containing gas into the melter gasifier by oxygen burners; and/or into the reducing-gas line.

2 . The process as claimed in claim 1 , wherein
the first reduction unit comprises at least a first and a second fluidized bed reactor, the fluidized bed reactors are connected by connecting lines for introducing the reducing gas into the fluidized bed reactors and for drawing off the reducing gas from the fluidized bed reactors, and the process further comprising: after flowing the reducing gas through the two fluidized bed reactors, drawing off the reducing gas as export gas; and the jetting or introducing the sulfur-containing coke-oven gas, the sulfur-containing natural gas, or the mixture of the sulfur-containing natural gas and the coke-oven gas together with the oxygen-containing gas is into at least one of the connecting lines by means of oxygen burners; and/or directly into at least one of the connecting lines.

3 . An apparatus configured for implementing a process as claimed in claim 1 , the apparatus comprising:
a first reduction unit having an export-gas line for outlet of export gas and a supply line for supplying iron oxide-containing charge materials to the first reduction unit; a melter gasifier connected via a reducing-gas line to the first reduction unit; at least one second reduction unit connected by the export-gas line to the first reduction unit; a CO 2 removal unit disposed in the export-gas line and configured for removing CO 2 , at least one iron product supply line, which opens into the melter gasifier, and a carbon carrier supply line into the melter gasifier; one or more introduction elements which open into the melter gasifier and the one or more introduction elements include an oxygen nozzle or a dust burner or an oxygen burner each having a media supply line for introducing a gas and/or a solid into the melter gasifier; at least one process-gas line for supplying a sulfur-containing coke-oven gas, a sulfur-containing natural gas, or a mixture of the sulfur-containing natural gas and the coke-oven gas, the process gas line opening into at least one of the media supply lines; and/or into at least one of the introduction elements; and/or into the reducing-gas line.

4 . The apparatus as claimed in claim 3 , further comprising:
the first reduction unit comprises at least a first and a second fluidized bed reactor, the fluidized bed reactors being connected by connecting lines for introducing the reducing gas into the fluidized bed reactors and for drawing off the reducing gas from the fluidized bed reactors; one or more introduction elements which open into at least one of the connecting lines and comprise oxygen nozzles, each introduction element having a media supply line for introducing a gas into the respective connecting line, and at least one process gas line for supplying the sulfur-containing coke-oven gas, the sulfur-containing natural gas, or the mixture of the sulfur-containing natural gas and the coke-oven gas; the at least one process gas line opening into at least one of the media supply lines; and/or into at least one of the introduction elements; and/or into at least one of the connecting lines.

5 . The apparatus as claimed in claim 3 , wherein the process-gas line comes from a plant which produces the sulfur-containing coke-oven gas, the sulfur-containing natural gas, or the mixture of the sulfur-containing natural gas and the coke-oven gas.

6 . The apparatus as claimed in claim 3 , wherein the process gas line comes from a plant for producing coke and/or a coal gasification plant and/or a source of the sulfur-containing natural gas.

Assignees

• Primetals Technologies Austria GmbH

Inventors

• Millner Robert

Classifications

• C21B7/002

  Evacuating and treating of exhaust gases · CPC title

• C21B2100/22

  by reforming · CPC title

• C21B2100/282

  of carbon dioxide · CPC title

• C21B13/143

  Injection of partially reduced ore into a molten bath · CPC title

• Y02P10/122

  by capturing or storing CO2 · CPC title