Cokeless sinter blend compositions

Abstract

Examples herein generally relate to sinter blend compositions for use in a sintering process that do not contain coke breeze (0.0% coke breeze), or contain only very small amounts of coke breeze. In particular, these sinter blend compositions are capable of repurposing mixture of iron-making reverts, having high total and metallic iron levels that re-oxidize so as to become a replacement fuel source for the coke breeze typically used in sinter blend compositions for use in a sintering process, while still managing to produce a sinter with sufficient ISO tumble strengths.

Claims

1. A sinter blend composition for use in a sintering process, comprising: a mixture of iron making reverts and a DF blend that is a blend of DRI fines having a component size distribution less than 6.8 mm where the DF blend comprises, by weight, between 77.00% and 84.00% total iron (Fe.sub.TOT), between 1.00% and 5.00% SiO.sub.2, between 0.05% and 3.00% Al.sub.2O.sub.3, between 4.00% and 8.00% CaO, between 0.05% and 1.50% MgO, between 4.00% and 8.50% C, and the remainder being impurities; and wherein the sinter blend composition is free of coke breeze and is configured to produce a sinter with an ISO tumble strength of at least 72.

2. The sinter blend composition of claim 1 wherein the mixture of iron making reverts comprise: a high metallic content blend comprising, by weight, between 68.0% and 74.0% total iron (Fe.sub.TOT) and having a majority of a component size distribution captured by sieve mesh sizes between 6.8 mm and 0.044 mm; an oxide blend comprising, by weight, between 63% and 68.5% total iron (Fe.sub.ToT) and having a majority of the component size distribution of less than 6.8 mm; a sludge blend comprising, by weight, between 53.00% and 59.00% total iron (Fe.sub.TOT) and having a majority of the component size distribution passing a sieve mesh size of less than 0.033 mm; and a dust blend comprising, by weight, between 76.00% and 82.00% total iron (Fe.sub.TOT) and having a majority of the component size distribution passing a sieve mesh size of less than 0.044 mm.

3. The sinter blend composition of claim 1, wherein the sinter blend composition comprises, by weight, at least 20.0% metallic iron.

4. The sinter blend composition of claim 3, wherein the sinter blend composition comprises, by weight, 21.69% metallic iron, with a corresponding estimated mix chemical energy of 1.92 GJ/t.

5. The sinter blend composition of claim 2, wherein the sinter blend composition comprises, by weight, between 38.0% and 44.0% high metallic content blend, between 27.0% and 34.0% oxide blend, between 4.0% and 8.0% sludge blend, between 0.5% and 4.5% dust blend and between 17.0% and 23.0% DF blend.

6. The sinter blend composition of claim 5, wherein the sinter blend composition comprises, by weight, approximately 41.3% high metallic content blend, approximately 30.6% oxide blend, approximately 5.9% sludge blend, approximately 2.2% dust blend and approximately 20.0% DF blend.

7. The sinter blend composition of claim 1, wherein the sinter produced from a cokeless sinter blend composition is characterized by: an ISO tumble strength of at least +6.35 mm: >75%; a reducibility of ISO 4695, R40: >1%; and a low temperature reduction-disintegration indices ISO 4696, +6.36 mm: >66%.

8. The sinter blend composition of claim 1, wherein the sinter blend composition additionally comprises one or more additives selected from the group consisting of limestone, quick lime, olivine and silica sand.

9. The sinter blend composition of claim 8, wherein the sinter blend composition contains additives comprising, by weight, between 10.00% and 14.00% limestone, between 0.50% and 4.00% quick lime, between 0.50% and 5.00% olivine and between 0.50% and 3.50% silica sand.

10. The sinter blend composition of claim 2, wherein the sinter blend composition comprises, by weight: approximately 33.87% high metallic content blend, approximately 25.09% oxide blend, approximately 4.84% sludge blend, approximately 1.80% dust blend, and approximately 16.40% DF blend; additives, comprising approximately 12.15% limestone, approximately 1.98% quick lime, approximately 2.56% olivine and approximately 1.31% silica sand; and having an ISO tumble strength of between 79.2 and 83.9.

11. The sinter blend composition of claim 1, wherein the sinter blend composition additionally comprises one or more fluxes in an amount necessary to meet target basicity, silica, and magnesium oxide levels in sinter.

12. The sinter blend composition of claim 11, wherein the one or more fluxes are selected from the group consisting of limestone, dolo-stone, quick lime, hydrated lime, milk of lime, magnesite, olivine, serpentine, and silica sand.

13. The sinter blend composition of claim 2, wherein the high metallic content blend and DF blend comprise metallic iron, iron oxide, silicon dioxide (SiO.sub.2), aluminum oxide (Al.sub.2O.sub.3), calcium oxide (CaO), magnesium oxide (MgO) and carbon (C).

14. The sinter blend composition of claim 13, wherein: the high metallic content blend comprises, by weight, between 1.0% and 3% SiO.sub.2, between 0.05% and 2.0% Al.sub.2O.sub.3, between 0.50% and 2.50% CaO, between 0.05% and 1.50% MgO, between 0.20% and 2.20% C; and the remainder being impurities.

15. The sinter blend composition of claim 2, wherein: the sinter blend composition additionally comprises water, with return fines of 30% of wet mix that is fired to produce sinter; and the sinter blend composition comprises, by weight: 33.87% high metallic content blend, 25.09% oxide blend, 4.84% sludge blend, 1.8% dust blend, 16.4% DF blend, with a calculated metallic blend percentage of 21.00%; and additives in the amount 12.15% limestone, 1.98% quick lime, 2.56% olivine and 1.31% silica sand.

16. The sinter blend composition of claim 1 comprising, by weight: a total dry mix of metallics of 21.69%; a total dry mix flux of 18.00% with a mix moisture of 7.6%, a return fines weight percentage of 30%; and an ISO tumble strength of 81.30.

17. The sinter blend composition of claim 2, wherein: the component size distribution of the DF blend passes a sieve mesh size of less than 0.147 mm.

18. The sinter blend composition of claim 1, wherein the sinter blend composition comprises, by weight, between 17.0% and 23.0% DF blend.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a photograph of an exemplary sinter formed from a sinter blend composition that is free of coke breeze.

(2) FIG. 2 is a chart showing the relationship between the percentages of coke breeze and metallics content in sinter blend compositions.

DETAILED DESCRIPTION

(3) In various embodiments, the inventive sinter blend compositions utilize a mixture of iron-making reverts such as DRI fines, dust and clarifier sludge, characterized by high metallic iron and total iron content levels in lieu of coke breeze, as the energy source in sinter blend compositions. In embodiments, the cokeless sinter blend composition may comprise a mixture of iron making reverts containing residues such as dust, fines and clarifier sludge resulting from the production of DRI and other additives that resultsafter the sintering processin a sinter with an ISO tumble strength greater than 72.

(4) TABLE-US-00001 TABLE 1 Component Chemistry Component Chemical Analysis Description Fe.sub.tot Fe.sup.++ SIO.sub.2 Al.sub.2O.sub.3 CaO MgO LOl C Fe met % H.sub.2O High Metallic Content Blend 71.31 2.24 1.89 0.95 1.48 0.19 6.61 1.16 21.00 3.8 Oxide Blend 66.34 0.65 2.28 1.43 0.82 0.03 0.94 5.7 Sludge Blend 56.19 14.02 4.34 1.82 9.69 0.67 2.35 1.92 8.06 16.3 Dust Blend 79.28 1.72 4.05 2.11 7.39 0.64 27.22 4.59 76.49 0.3 DF Blend 80.55 1.69 2.99 1.29 5.94 0.50 26.86 6.41 78.07 0.5 Quick Lime 0.04 1.13 0.34 92.12 4.77 2.90 0 Limestone 0.05 0.82 0.17 53.58 0.90 43.67 5.5 Olivine 6.24 4.78 40.45 0.30 0.01 52.46 0.24 % Ash 1.5 Coke Breeze 0.92 6.14 2.86 0.49 0.19 88.2 87.5 11.84 21 Silica Sand 0.71 98.22 0.19 0 0 BDL = Below Detection Limit Negative LOl = Gain on Ignition

(5) Table 1 identifies the chemical compositions of various mixtures of iron-making reverts, which were tested as sinter blend compositions. Such test sinter blend compositions comprised various mixtures of iron-making reverts that included one or more of a high metallic content blend, oxide blend, sludge blend, dust blend, and DRI fines (hereafter, DF blend). Optionally, the sinter blend compositions also comprised additives such as limestone, silica sand, quick lime, and olivine. See Tables 1-4.

(6) TABLE-US-00002 TABLE 2 Component Size Distribution Component Size Analysis, % wt On Size mesh 3 4 6 8 10 14 20 28 mm 12.7 9.525 6.8 4.7 3.3 2.36 1.65 1.168 0.833 0.589 Description High Metallic Content Blend 15.2 16.1 10 6.4 2.9 6.4 2.9 2.9 Oxide Blend 0.0 8.8 10.5 2 0.7 0.5 1.5 1.4 2.0 Sludge Blend 0.0 0.0 0.2 0 0.0 0.0 0.0 0.2 1.2 Dust Blend 0.0 0.0 0.0 0 0.0 0.0 0.0 0.0 0.0 DF Blend 0.0 0.0 0.0 0 0.0 0.0 0.0 0.0 0.0 Quick Lime 0.00 0.00 0.0 0.00 0.00 0.00 0.00 0.00 Limestone 0.29 2.02 5.6 15.70 8.24 23.78 10.26 7.79 Olivine 0.00 0.00 0.0 0.00 0.00 0.00 5.17 25.16 Coke Breeze 0.00 1.30 6.45 10.4 10.42 4.33 12.19 6.49 7.55 Silica Sand 0.00 mesh 35 48 65 100 150 200 270 325 325 mm 0.417 0.295 0.208 0.147 0.104 0.074 0.053 0.044 Description High Metallic Content Blend 2.1 1.7 1.5 1.4 1.6 2.0 2.5 1.3 22.7 Oxide Blend 1.8 1.8 1.8 1.8 1.8 2.2 3.7 2.8 54.9 Sludge Blend 1.8 2.2 2.4 3.3 4.3 6.5 9.1 5.1 63.9 Dust Blend 0.0 0.0 0.0 0.0 0.1 0.3 1.1 1.1 97.4 DF Blend 0.0 0.0 0.0 0.0 0.1 0.2 1.2 1.5 97.0 Quick Lime 0.00 0.00 0.00 1.95 1.85 4.25 2.60 0.25 89.0 Limestone 5.11 3.71 2.68 1.77 1.07 0.78 0.58 0.21 10.3 Olivine 39.32 21.47 3.00 0.52 1.05 1.77 1.28 0.27 0.99 Coke Breeze 7.51 7.31 6.53 5.15 3.69 2.79 1.97 0.67 5.42 Silica Sand 3.57 25.21 31.69 30.84 8.19 0.50 0.00 0.00 0.00

(7) The component size distribution for the various blends is summarized in Table 2. The mixing and granulation processes employed in the production of the sinter blend compositions disclosed herein are conventional, and may include one or more of the addition of water to produce slurries, screening of blends to remove oversize pellets, and/or use of medium or high intensity mixing devices.

(8) Disclosed herein is a cokeless sinter blend composition for use in a sintering process, which comprises a mixture of DRI making reverts. The DRI reverts may comprise one or more of a high metallic content blend, an oxide blend, a sludge blend, a dust blend, and a DF blend. In embodiments, the sinter blend composition may comprise only a mixture of iron-making reverts, be free of coke breeze, and be capable of producing a sinter with an ISO tumble strength of at least 72. In some embodiments, the quality of sinter produced from a coke free sinter blend composition may be characterized by having an ISO tumble strength of at least +6.35 mm: >75%; a reducibility of ISO 4695, R40: >1% and an [low temperature reduction-disintegration indices] ISO 4696, +6.36 mm: >66%. Unless otherwise indicated all compositions are given in weight percent.

(9) In embodiments, the sinter blend composition may comprise between 38.0% and 44.0% high metallic content blend, between 27.0% and 34.0% oxide blend, between 4.0% and 8.0% sludge blend, between 0.5% and 4.5% dust blend and between 17.0% and 23.0% DF blend. The sinter blend composition may comprise, by weight, approximately 41.3% high metallic content blend, approximately 30.6% oxide blend, approximately 5.9% sludge blend, approximately 2.2% dust blend and approximately 20.0% DF blend.

(10) In one embodiment, the sinter blend composition may comprise the composition, and corresponding characteristics, shown in Table 3. In embodiments, the cokeless sinter blend composition comprises, by weight, at least about 20.0% metallic iron. In embodiments, the cokeless sinter blend composition comprises 21.69% metallic iron, and 0.0% coke breeze, with a corresponding estimated mix chemical energy of 1.92 GJ/t. See Table 3 in case of a shortfall in the availability of DF Blend, the balance mix chemical energy may be met with the addition of low levels of coke breeze, as discussed infra. In embodiments, the cokeless sinter blend composition may additionally comprise one or more additives, including one or more of limestone, quick lime, olivine and silica sand.

(11) TABLE-US-00003 TABLE 3 Sinter Test Summary Triplicated Test # 1 2 3 Comments S. Fines S. Fines S. Fines Comments 2% Lime 2% Lime 2% Lime Target Moisture % Wt 8.70 8.70 8.70 Measured, Mix % wt Moist 7.70 7.60 7.60 Blend, % wt Dry Basis High Metallic Content Blend 33.87 33.87 33.87 Oxide Blend 25.09 25.09 25.09 Sludge Blend 4.84 4.84 4.84 Dust Blend 1.80 1.80 1.80 DF Blend 16.40 16.40 16.40 Silica Sand 1.31 1.31 1.31 Limestone 12.15 12.15 12.15 Quick Lime 1.98 1.98 1.98 Olivine 2.56 2.56 2.56 Coke Breeze 0.00 0.00 0.00 Raw Mix Totals 100.0 100.0 100.0 Total Flux Addition, % Dry Basis 18.0 18.0 18.0 Raw Mix, % wt 70.0 70.0 70.0 Est. % Metallics in Sinter Mix, % wt 21.69 21.69 21.69 Return Fines in Mix, % wt 30.0 30.0 30.0 Est. Mix Chemical Energy, GJ/t 1.92 1.92 1.92 Target CaO/SiO.sub.2 2.40 2.40 2.40 Target % SiO.sub.2 4.37 4.37 4.37 Target % MgO 1.72 1.72 1.72 Press., mbar 162 162 162 Max Ignition Temp., C. 1309 1283 1274 Max Ave. Wind Box Temp, min 21.08 23.00 20.75 Max Ave. Wind Box Temp., C. 501 472 446 Max H, Layer Temp., min 17.25 26.00 23.00 Hearth Layer Temp., C. 1146 1204 1314 Pot Bulk Density (wet), kg/m.sup.3 2040.7 2169.1 2088.5 Wet Mix Depth, in (18 = 450 mm) 18.0 18.0 18.0 Bed Shrinkage, % Starting Depth 0.0 0.0 10.3 Productivity Ave Wbox Temp, Mt/m.sup.2-24 hr 40.74 39.62 42.27 Hearth Layer Temp, Mt/m.sup.2-24 hr 49.78 35.05 38.13 Wt Recovery 99.57 99.31 99.26 Averaged Returns Ratio (Out/In) 0.97 1.04 0.87 Averaged Returns Ratio (In/Out) 1.03 0.97 1.15 % Returns in Mix (Dry Basis) 30.00 30.00 30.00 ISO-3271 Tumble % wt. +6.3 mm 79.2 80.8 83.9 Product (5 mm +6.3 mm) Fe.sub.Tot 57.94 58.48 58.34 FeO 9.52 9.51 9.75 Fe.sub.met 1.79 1.62 1.61 SiO.sub.2 4.60 4.56 4.47 Al.sub.2O.sub.3 0.99 1.00 0.95 CaO 10.61 10.67 10.71 MgO 1.74 1.73 1.71 C 0.04 0.03 0.02 B2 = CaO/SiO.sub.2 2.31 2.34 2.40 B4 = (CaO + MgO)/(SiO2 + Al2O3) 2.21 2.24 2.31 Return Fines 6.3 mm 57.16 57.46 57.37 FeO 8.48 10.47 9.88 Fe.sub.met 1.39 2.68 2.31 SiO.sub.2 4.87 4.80 4.81 Al.sub.2O.sub.3 1.13 1.06 1.00 CaO 11.27 11.14 11.38 MgO 1.97 1.99 2.05 C 0.08 0.18 0.07 CaO/SiO.sub.2 2.31 2.32 2.37 Product Conditioning Size Distribution 50.8 + 38.1 mm 2.7 3.0 3.6 38.1 + 25.4 mm 9.9 13.1 12.3 25.4 + 19.1 mm 15.5 14.6 17.5 19.1 + 15.9 mm 8.3 6.9 7.1 15.9 + 12.7 mm 8.1 6.2 7.2 12.7 + 9.5 mm 17.1 15.4 15.4 9.5 + 6.3 mm 13.6 13.5 13.3 6.3 mm 24.8 27.2 23.6 Totals 100.00 100.00 100.00 Metallurgical Tests ISO-4695 Reducibility, R.sub.40 %/min 1.05 1.08 1.14 ISO-4696-1 LTD % wt. +6.3 mm 68.0 70.0 61.6 % wt. 6.3 + 3.15 19.6 19.8 24.3 % wt. 3.15 + 32M (0.5 mm) 10.2 8.1 11.6 % wt 32M (0.5 mm) 2.2 2.1 2.5

(12) In some embodiments, the sinter blend composition may be free (0.0%) of coke breeze (or other carbonaceous materials, including biomass) and comprise, by weight, between 33.0% and 40.0% high metallic content blend, between 25.0% and 30.0% oxide blend, between 0.0% and 5.0% sludge blend, between 0.0% and 2.2% dust blend, and between 14.0% and 18.0% DF blend, with the remainder comprising impurities and/or one or more fluxes in an amount necessary to meet target basicity, silica and MgO levels in sinter. In various embodiments, the fluxes may comprise one or more of limestone, dolo-stone, quick lime, hydrated lime, milk of lime, other calcareous materials, magnesite, olivine, serpentine, silica sand, or other such components known to persons of skill in the art. In one embodiment, the sinter blend composition may comprise between 10.00% and 14.00% limestone, between 0.50% and 4.00% quick lime, between 0.50% and 5.00% olivine and between 0.50% and 3.50% silica sand. In embodiments, the total iron metallics in the sinter blend may be less than or equal to 22.0%. In embodiments, the sinter blend compositions may be free of coke breeze and comprise, by weight, approximately 33.87% high metallic content blend, approximately 25.09% oxide blend, approximately 4.84% sludge blend, approximately 1.80% dust blend, approximately 16.40% DF blend, approximately 12.15% limestone, approximately 1.98% quick lime, approximately 2.56% olivine and approximately 1.31% silica sand, which resulted in sinter having an ISO tumble strength of between 79.2 and 83.9. See Table 3.

(13) In embodiments, the chemical composition of the high metallic content blend of the sinter blend composition may comprise, at least, iron (Fe), silicon dioxide (SiO.sub.2), aluminum oxide (Al.sub.2O.sub.3), calcium oxide (CaO), magnesium oxide (MgO) and carbon (C). In embodiments, the high metallic content blend may comprise, by weight, between 68.0% and 74.0% total iron (Fe.sub.TOT) levels, between 1.0% and 3% SiO.sub.2, between 0.05% and 2.0% Al.sub.2O.sub.3, between 0.50% and 2.50% CaO, between 0.05% and 1.50% MgO, and between 0.20% and 2.20% C, with the remainder being impurities. The high metallic content blend may also comprise, by weight, approximately 71.31% total iron (Fe.sub.T0T) levels, approximately 1.89% SiO.sub.2, approximately 0.95% Al.sub.2O.sub.3, approximately 1.48% CaO, approximately 0.19% MgO, approximately 1.16% C, with the remainder being impurities.

(14) In embodiments, the chemical composition of the oxide blend of the sinter blend composition may comprise, at least, iron (Fe), silicon dioxide (SiO.sub.2), aluminum oxide (Al.sub.2O.sub.3), calcium oxide (CaO), and magnesium oxide (MgO). In embodiments, the oxide blend may comprise, by weight, between 63.00% and 68.50% Fe.sub.TOT, between 1.00% and 3.50% SiO.sub.2, between 0.50% and 2.50% Al.sub.2O.sub.3, between 0.05% and 2.00% CaO, and between 0.01% and 1.50% MgO, with the remainder being impurities. In embodiments, the oxide blend may comprise, by weight, approximately 66.34% Fe.sub.T0T, approximately 2.28% SiO.sub.2, approximately 1.43% Al.sub.2O.sub.3, approximately 0.82% CaO, and approximately 0.03% MgO, with the remainder being impurities.

(15) In embodiments, the chemical composition of the sludge blend of the sinter blend composition may comprise, at least, iron (Fe), silicon dioxide (SiO.sub.2), aluminum oxide (Al.sub.2O.sub.3), calcium oxide (CaO), magnesium oxide (MgO) and carbon (C). In embodiments, the sludge blend may comprise, by weight, between 53.00% and 59.00% total iron (Fe.sub.TOT) levels, between 3.00% and 6.00% SiO.sub.2, between 0.50% and 3.00% Al.sub.2O.sub.3, between 8.00% and 12.00% CaO, between 0.05% and 2.00% MgO, and between 0.50% and 3.00% C, with the remainder being impurities. The sludge blend may also comprise, by weight, approximately 56.19% total iron (Fe.sub.TOT) levels, approximately 4.34% SiO.sub.2, approximately 1.82% Al.sub.2O.sub.3, approximately 9.69% CaO, approximately 0.67% MgO, and approximately 1.92% C, with the remainder being impurities. In embodiments, the sludge blend may comprise between 10.0% and 20.0% water, or approximately 16.3% water.

(16) In embodiments, the chemical composition of the dust blend of the sinter blend composition may comprise, at least, iron (Fe), silicon dioxide (SiO.sub.2), aluminum oxide (Al.sub.2O.sub.3), calcium oxide (CaO), magnesium oxide (MgO) and carbon (C). In embodiments, the dust blend may comprise, by weight, 76.00% and 82.00% total iron (Fe.sub.TOT) levels, between 2.00% and 6.00% SiO.sub.2, between 1.00% and 3.50% Al.sub.2O.sub.3, between 5.00% and 9.500% CaO, between 0.05% and 1.50% MgO, and between 3.00% and 6.00% C, and the remainder impurities. The dust blend may also comprise, by weight, approximately 79.28% total iron (Fe.sub.TOT) levels, approximately 4.05% SiO.sub.2, approximately 2.11% Al.sub.2O.sub.3, approximately 7.39% CaO, approximately 0.64% MgO, and approximately 4.59% C, with the remainder being impurities. In embodiments, the dust blend may comprise between 0.01% and 1.0% water, or approximately 0.3% water.

(17) In embodiments, the chemical composition of the DF blend of the sinter blend composition may comprise, at least, iron (Fe), silicon dioxide (SiO.sub.2), aluminum oxide (Al.sub.2O.sub.3), calcium oxide (CaO), magnesium oxide (MgO) and carbon (C). In embodiments, the DF blend may comprise, by weight, between 77.00% and 84.00% total iron (Fe.sub.TOT) levels, between 1.00% and 5.00% SiO.sub.2, between 0.05% and 3.00% Al.sub.2O.sub.3, between 4.00% and 8.00% CaO, between 0.05% and 1.50% MgO, and between 4.00% and 8.50% C, with the remainder being impurities. The DF blend may also comprise, by weight, approximately 80.55% total iron (Fe.sub.TOT) levels, approximately 2.99% SiO.sub.2, approximately 1.29% Al.sub.2O.sub.3, approximately 5.94% CaO, approximately 0.50% MgO, and approximately 6.41% C, with the remainder being impurities.

(18) In still other embodiments, the sinter blend composition may comprise a mixture of iron-making reverts (including, at least, a DF blend) and coke breeze or other carbonaceous materials, including bio-mass. The relative relationship between the amount of metallics content to coke content is shown in FIG. 2. In embodiments combining iron making reverts and coke breeze, the levels of coke breeze may be significantly reduced so as to save on the cost of producing the sinter blend composition, and include only those amounts as may be necessary to meet the mix chemical energy requirements. In these embodiments, the iron-making reverts may contain, by weight, between 10.0% and 20.0% metallic iron levels, or at least 20.0% metallic iron levels. In certain embodiments, the sinter blend composition may comprise, by weight, between 0.01 and less than about 5.0% coke breeze. In various embodiments, shown generally in FIG. 2, the sinter blend composition may comprise approximately 4% coke breeze, 2% coke breeze, or less than about 0.5% coke breeze. In these embodiments, the sinter blend composition combining iron making reverts and coke breeze may be configured to produce sinter with an ISO tumble strength of at least 72. In one embodiment, the sinter blend composition may comprise, by weight, less than 4.5% coke breeze, with a metallic iron level of at least 10%. In one embodiment, the sinter blend composition may comprise, by weight, approximately 3.0% coke breeze, with an increased metallic iron level of approximately 15.0%, or less than 3.0% coke breeze, with a metallic iron level of at least 15.0%. In embodiments where the sinter blend composition contains only small amounts of coke breeze, the high total and metallic iron levels act as the principal fuel source for the sintering process, while still producing sinter with an acceptable ISO tumble strength.

(19) In embodiments, the high metallic content blend, an oxide blend, a sludge blend, a dust blend, DF blend and additives may additionally comprise varying levels of water (H.sub.2O).

(20) TABLE-US-00004 TABLE 4 Cokeless Sinter % Wt. Components Blend DRI High Metallic Content Blend 33.87 Reverts Oxide Blend 25.09 Sludge Blend 4.84 Dust Blend 1.8 DF Blend 16.4 % Metallic Blend (calc) 21.00 Additives Coke Breeze 0.00 Limestone 12.15 Quick Lime 1.98 Olivine 2.56 Silica Sand 1.31 Return Fines at 30% of Wet Mix

(21) Table 4 shows an exemplary cokeless sinter blend with return fines of 30% of wet mix that is fired to produce sinter. This composition comprises DRI reverts comprising, by weight, 33.87% high metallic content blend, 25.09% oxide blend, 4.84% sludge blend, 1.8% dust blend, 16.4% DF blend, and a calculated metallic blend percentage of 21.00%. The composition further comprises additives in the amount of 0.00% coke breeze, 12.15% limestone, 1.98% quick lime, 2.56% olivine and 1.31% silica sand.

(22) TABLE-US-00005 TABLE 5 Sinter Produced Mix Moisture, % wt. 7.6 Coke Add'n, % wt. 0 Dry Mix Metallics, % wt. 21.69 Dry Mix Tot. Flux, % wt. 18.00 SiO.sub.2, % wt. 4.54 CaO, % wt. 10.66 MgO, % wt. 1.73 B2 (CaO/SiO.sub.2) 2.35 Residual Metallics in Product, % wt. 1.67 Return Fines, % wt. 30.00 Ave. Returns Ratio (Fines Out/Fines In) 0.96 ISO Tumble, +6.3 mm, % wt. 81.30 Ave Prod. (Wind Box), Mt/m.sup.2-24 hr 40.87 ISO-4695 R.sub.40 %/min 1.09 ISO 4696 +6.3 mm, % wt. 66.53 ISO-4696 0.5 mm, % wt. 2.27

(23) Table 5 is an analysis of an exemplary cokeless sinter produced in accordance with the present invention, comprising, by weight, a total dry mix of metallics of 21.69%; a total dry mix flux of 18.00% with a mix moisture of 7.6%, a return fines weight percentage of 30% and an ISO tumble strength of 81.30. FIG. 1 is a photograph of an exemplary sinter formed from a sinter blend composition that is free of coke breeze.

(24) In one embodiment, the sinter blend composition for use in a sintering process may comprise, by weight: 33.87% high metallic content blend, 25.09% oxide blend, 4.84% sludge blend, 1.8% dust blend, 16.4% DF blend, plus additives in the amount of 0.00% coke breeze, 12.15% limestone, 1.98% quick lime, 2.56% olivine and 1.31% silica sand; wherein the calculated metallics percentage is 21.69%, with a corresponding estimated mix chemical energy of 1.92 GJ/t, an ISO tumble strength of at least +6.35 mm 75%, a reducibility of ISO 4695, R40: >1%, and a low temperature reduction-disintegration indices ISO 4696, +6.36 mm: >66%.

(25) In utilizing the sinter blend compositions disclosed herein, it can be appreciated that DRI revertsthat are effectively difficult and expensive to dispose of waste by-productscan be repurposed in a meaningful way to produce sinters with good quality mechanical properties (such as strong ISO tumble strength ratings), excellent transportation capabilities (because the DRI fines and dust have been rendered inert), and economical (because the expensive coke breeze has been replaced with waste materials).

(26) While it has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made, and that combinations and equivalents of the above-described sinter blend composition component features may be combinable with other features, and may otherwise be substituted, re-arranged, and claimed in different ways without departing from scope. In addition, many modifications may be made to adapt a particular situation or material to the teachings without departing from its scope. Therefore, it is intended that it not be limited to the particular embodiments disclosed, but that it will include all embodiments falling within the scope of the detailed description and appended claims.