Pre-treatment process for feed material for direct reduction process
AssigneeRio Tinto Brasil
InventorsStephen M. Potter, John Y. Clark
Life of this patent
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Abstract
A pretreatment process for solid lump feed material for a gas and pellet/lump-based direct reduction process, comprising preheating feed material to a temperature of from about 200 C to about 500 C, without reduction, in a non-reducing atmosphere prior to charging the feed material to gas-based direct reduction furnace, thereby minimizing the formation of fines within the furnace.
Claims6
A pre-treatment process for solid lump feed material for a gas and pellet/lump-based shaft furnace direct reduction process, comprising:
- preheating and predrying hematite lump feed material to a temperature of from about 200° C. to less than or equal to 500° C., without reduction, in a non-reducing atmosphere prior to charging the feed material to gas-based direct reduction furnace;
- transporting the lump feed material through an insulated charging system having either an inert or oxidizing atmosphere;
- charging the feed material from the insulated charging system to the furnace;
- and
- increasing the temperature of the pre-heated feed material within the furnace from the material introduction temperature to about 750° C. within the first 20 minutes of charging the feed material into the furnace;
- whereby the formation of fines within the furnace is minimized.
A pre-treatment process for solid lump feed material for a gas and pellet/lump-based shaft furnace direct reduction process, comprising:
- preheating and predrying hematite lump feed material to a temperature of from about 200° C. to less than or equal to 500° C., without reduction, in a non-reducing atmosphere prior to charging the feed material to gas-based direct reduction furnace;
- transporting the lump feed material through an insulated charging system having either an inert or oxidizing atmosphere;
- charging the feed material from the insulated charging system to the furnace;
- and
- increasing the temperature of the preheated feed material within the furnace from the material introduction temperature of less than or equal to 500° C. to about 750° C. in less than 20 minutes while the feed material descends the first half meter in the furnace after introduction of the feed material into the moving bed of the furnace;
- whereby the formation of fines within the furnace is minimized.
Dependencies are inferred from the claim text.