Method for producing metallic iron particles
AssigneeMidrex Corporation
InventorDonald Beggs
Life of this patent
Estimating the term…
Abstract
A method of producing iron particles in a generally vertical furnace in which a gravitational flow of particulate material is reduced in a reducing zone by a countercurrent flow of a reducing gas containing a reductant, the spent reducing gas is removed and cooled and a portion is introduced as cooling gas in a cooling zone near the bottom of the furnace, and a portion of the cooling gas is upgraded in reducing potential and introduced to the reducing zone as reducing gas. Apparatus is also provided for carrying out the method.
Claims13
A method for producing a metallized product comprising:
- a. establishing a gravitational flow of particulate metal oxide material by charging the particulate metal oxide material to the upper portion of a generally vertical furnace having an upper reducing zone and a lower cooling zone, and removing the metallized product from the bottom of the furnace;
- b. introducing a reducing gas to the gravitational flow of material at a temperature sufficient to promote a reducing reaction between said reducing gas and said material at a first inlet intermediate the ends of the furnace;
- c. causing said reducing gas to move countercurrent through the gravitational flow of material, react with and reduce a substantial portion of the metal oxide and form a top gas;
- d. removing said top gas from the upper portion of the furnace;
- e. cooling said top gas;
- f. introducing a portion of said cooled top gas as cooling gas into a second inlet near the lower end of said furnace;
- g. removing a first portion of said cooling gas from said furnace at a location intermediate said first and second inlets;
- h. adding said removed portion of said cooling gas to said top gas prior to step (e);
- and
- i. causing a second portion of said cooling gas to flow upwardly through the gravitational flow of material, become heated thereby, and act as a reducing gas in the reducing zone;
- whereby that portion of said cooling gas flowing upwardly through the gravitational flow of material has a greater reducing potential than the spent top gas, and is thus an effective reductant.
A method for producing metallized pellets comprising:
- a. establishing a gravitational flow of metal oxide material in a vertical shaft furnace;
- b. introducing a gaseous reductant at an intermediate location within said furnace through a first inlet whereby the gaseous reductant moves in counterflow relationship with the descending metal oxide burden;
- c. removing the top gas which is the reacted gaseous reductant from the upper portion of the furnace;
- d. cooling said top gas;
- e. introducing a portion of the cooled top gas as a cooling gas directed into the vertical shaft furnace at a second inlet below said first inlet whereby said cooling gas is in direct heat exchange relationship with the descending burden;
- f. removing a portion of the cooling gas at an outlet intermediate to said first and second inlets;
- and
- g. adding said removed cooling gas to said removed top gas prior to step (d);
- whereby the cooling gas, upon reacting with the metallized burden between said second inlet and said outlet have a greater reducing potential than does the spent top gas.
Dependencies are inferred from the claim text.