Production of iron using environmentally-benign renewable or recycled reducing agents

Abstract

To produce metallic iron from iron ore, a composition comprising a mass of material formed from a mixture of iron ore particles and particles of a reductant that is either a biomass material in particulate form or a plastic resinous material in particulate form is used. The reductant can also be a mixture of biomass material and resin in any proportions. The mass of material comprises at least one body having a shape adapted for smelting such as pellets, briquettes, pieces or lumps. The pellets have sufficient cohesion to maintain the shape into which they have been formed. The invention also provides a new method for smelting iron from its ore which comprises subdividing the ore into particles of a selected size, mixing the subdivided ore particles with particles of a biomass material or particles of a plastic resinous material or with mixtures thereof, forming a mass of the mixture into at least one body with a shape that is suited for smelting in a furnace and placing the body in a furnace and exposing it to sufficient heat to bring the iron therein to smelting temperature within the furnace to thereby produce metallic iron directly from the ore.

Description

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagrammatic vertical sectional view taken through a furnace showing the reduction of iron ore in accordance with the present invention.

FIG. 2 is a vertical sectional view taken through the crucible shown in FIG. 1 on a larger scale with an iron ore mass as it appears before smelting in the furnace.

FIG. 3 shows the appearance of a typical pellet after smelting to illustrate metallic iron bodies separate from the slag and

FIG. 4 is a diagrammatic longitudinal sectional representation of one example to illustrate the use of the invention on an industrial scale.

Claims

1. A composition for producing metallic iron from iron ore comprising, a mass formed from a mixture of iron ore particles and particles of a reductant selected from the group consisting of biomass material and particles of plastic resinous matter or mixtures thereof and the mass having a selected form that is adapted to be smelted within a furnace for producing metallic iron.

2. The composition of claim 1 wherein the mass is a coherent mass comprising a pellet, briquette, piece or lump.

3. The composition of claim 1 wherein the reductant particles are poorly adherent and a binder is present in the mass for binding the particles to each other.

4. The composition of claim 1 wherein said mass comprises about 60% to about 90% iron ore by weight.

5. The composition of claim 1 wherein the iron ore is selected from the group consisting of magnetite, hematite or limonite.

6. The composition of claim 1 wherein the plastic resinous matter is a substantially chlorine-free plastic resin.

7. For use in the production of metallic iron from its ore, a coherent mass of iron ore particles mixed with particles of a reductant selected from the group consisting of biomass matter that is substantially devoid of free carbon and plastic resin particles or mixtures thereof and said mass being formed into bodies for smelting within a furnace to produce metallic iron therefrom.

8. The composition of claim 7 wherein the mass is a coherent mass comprising a pellet, briquette, piece or lump.

9. The composition of claim 7 wherein the reductant particles are poorly adherent and a binder is present in the mass for binding the particles to each other.

10. The composition of claim 7 wherein said mass comprises about 60% to about 90% iron ore by weight.

11. The composition of claim 7 wherein the iron ore is selected from the group consisting of magnetite, hematite or limonite and comprises about 65% to about 85% of the mass by weight.

12. A method of producing metallic iron from iron ore comprising, providing iron ore in particulate form,admixing particles of a reductant with the iron ore particles, said reductant being selected from the group consisting of biomass material and particles of a plastic resinous material or mixtures thereof to form a mass therefrom,placing the mass into at least one body having a selected form andfiring the mass in a furnace that is heated to a temperature that is sufficient to reduce the iron ore to metallic iron and to melt the iron whereby the iron forms at least one body of metallic iron and slag.

13. The method of claim 12 wherein the slag is thereafter separated from the metallic iron body.

14. The method of claim 12 wherein the mass is heated to a temperature of at least about 1300° C.

15. The method of claim 12 wherein the mass is a coherent mass that is formed into agglomerates comprising pellets that are from about ½ to 4 cm in diameter.

16. The method of claim 12 wherein a binder is admixed with the reductant and ore to bond the particles within the mass to one another.

17. The method of claim 12 wherein the mass is coherent mass which is formed into bodies that are about ½ to about 2½ cm in diameter.

18. The method of claim 12 including the step of providing as said iron ore particles, ground ore particles of magnetite, hematite or laminate.

19. The method of claim 12 wherein the mass is coherent mass of particles that is formed into an agglomerated body and the body is placed on a refractory material within the furnace to support the agglomerated body.

20. The method of claim 12 including the step of providing as the biomass material a material selected from the group consisting of paper, paper pulp, cellulosic paper mill waste sludge, ground wood, wheat flour, corn meal, dried sugar beet waste pulp, grass clippings, chopped straw, corn stalks, sawmill waste, dried post consumer organic waste, dried sewage sludge, peat, starch, gluten, lignin, dried distillers grain, solid residues from alcohol production, molasses, switchgrass and the plastic resinous material comprises a hydrocarbon comprising polypropylene plastic resin, polyethylene plastic resin, polyvinyl chloride plastic resin or mixtures thereof.

21. The composition of claim 1 wherein the biomass material is a material selected from the group consisting of paper, paper pulp, cellulosic paper mill waste sludge, ground wood, wheat flour, corn meal, dried sugar beet waste pulp, grass clippings, chopped straw, corn stalks, sawmill waste, dried post consumer organic waste, dried sewage sludge, peat, starch, gluten, lignin, dried distillers grain, solid residues from alcohol production, molasses, switchgrass and the plastic resinous matter is selected from polypropylene plastic resin, polyethylene plastic resin, polyvinyl chloride plastic resin.

22. The method of claim 12 including placing the mass on a supporting bed of a refractory material.

23. The method of claim 12 including the step of placing the mass on a supporting bed of refractory material comprising loose particles of a refractory substance in particulate form.

24. The method of claim 22 wherein the mass is placed on a refractory material comprising alumina and boron nitride, mullite and zirconia, carbon particles or graphite.