Sintered ore prepared from high-magnesium iron ore powder and preparation method of sintered ore

Abstract

The sintered ore is prepared from the following raw materials in percentage by mass: 0%-20.0% of high-magnesium iron ore powder A, 35.0%-50.0% of iron ore concentrate B, 15.0%-35.0% of iron ore powder C, 3.0%-20.0% of iron ore powder D, 3%-10% of iron ore powder E, 2%-10% of a high-silicon flux F, 0%-6.0% of dolomite, 0%-5.0% of limestone, 0%-4.0% of quick lime and 0.5%-6.0% of coke powder. 5.0%-15.0% of blast furnace return mine; the preparation method comprises the following steps: adding water into the raw materials, mixing, and granulating to obtain a mixture; and sintering the mixture to obtain the sintered ore. In the sintering production process, a certain proportion of high-magnesium-oxide-content iron ore is used, the magnesium oxide content of the sintered ore is guaranteed, meanwhile, the use amount of magnesium-containing flux is reduced, and therefore the cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of sinter preparation technology, and particularly relates to a sinter prepared using high-magnesium iron ore powder and its preparation method. Background Technology

[0002] Sinter is one of the main raw materials for blast furnace smelting in ironmaking. The preparation of sinter requires mixing, granulation, sintering, cooling, and sizing of iron ore, basic flux, magnesium-containing flux, and fuel. Generally, sintering requires the addition of a certain amount of magnesium-containing flux to ensure a certain magnesium oxide content in the sinter, thereby guaranteeing its excellent metallurgical properties. Sinter with a certain magnesium oxide content, when added to the blast furnace, provides good blast furnace slag flowability and desulfurization capabilities. Typically, the magnesium oxide content in iron ore used for sintering is low, generally below 1%. Using iron ore with high magnesium oxide content to produce sinter, while ensuring the required magnesium oxide content, and reducing the amount of magnesium-containing flux, is one way to reduce the cost of sinter. Summary of the Invention

[0003] The purpose of this invention is to provide a sintered ore prepared using high-magnesium iron ore powder and its preparation method. The technical problem to be solved is to use a certain proportion of high-magnesium iron ore in the sintering production process, so as to reduce the amount of magnesium-containing flux while ensuring the magnesium oxide content of the sintered ore, thereby reducing flux costs and, to a certain extent, reducing fuel consumption, thereby reducing fuel costs.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] This invention discloses a sintered ore prepared using high-magnesium iron ore powder, with the following raw material proportions by mass percentage: high-magnesium iron ore powder A 0%-20.0%, iron concentrate B 35.0%-50.0%, iron ore powder C 15.0%-35.0%, iron ore powder D 3.0%-20.0%, iron ore powder E 3%-10%, high-silicon flux F 2%-10%, dolomite 0%-6.0%, limestone 0%-5.0%, quicklime 0%-4.0%, coke powder 0.5%-6.0%, and blast furnace return ore 5.0%-15.0%.

[0006] Furthermore, the high-magnesium iron ore powder A comprises the following components by mass percentage: TFe 56.30–62.50%, FeO 18.50–25.00%, CaO 0.80–1.80%, SiO2 3.50–8.50%, MgO 3.00–4.50%, F 0.10–0.40%, P 0–0.10%, and S 0.15–0.80%, and the loss on ignition of the iron concentrate A is 1.15–3.15%.

[0007] Furthermore, the iron concentrate B comprises the following components by mass percentage: TFe 62.5–68.50%, FeO 25.0–29.5%, CaO 0.50–1.50%, SiO 21.50–3.50%, MgO 0.25–1.20%, F 0.15–0.50%, P 0–0.10%, and S 0.50–1.20%, and the loss on ignition of the iron concentrate B is 1.2–3.00%.

[0008] Furthermore, the iron ore powder C comprises the following components by mass percentage: TFe 58.30–62.50%, FeO 0–1.0%, CaO 0–0.4%, SiO2 3.0–6.0%, MgO 0–0.40%, P 0–0.15%, and S 0.01–0.10%, and the loss on ignition of the iron ore powder C is 2.5–7.5%.

[0009] Furthermore, the iron ore powder D comprises the following components by mass percentage: TFe 58.30–62.50%, FeO 0–1.0%, CaO 0–0.4%, SiO2 3.0–6.0%, MgO 0–0.40%, P 0–0.15%, and S 0.01–0.10%, and the loss on ignition of the iron ore powder D is 2.5–7.5%.

[0010] Furthermore, the iron ore powder E comprises the following components by mass percentage: TFe 56.00–60.50%, FeO 0–1.0%, CaO 0–0.4%, SiO2 3.0–7.0%, MgO 0–0.30%, P 0–0.15%, and S 0.01–0.10%, and the loss on ignition of the iron ore powder D is 5.0–9.5%.

[0011] Furthermore, the basicity of the sinter is 1.90-2.10, and the mass percentage of MgO in the sinter is 1.85%-2.25%.

[0012] Further, the raw materials are mixed with water and granulated to obtain a mixture; the mixture is sintered to obtain sintered ore; wherein: the granulation time is 2-5 min; the water content in the mixture is 7%-9% by mass; the ignition time for sintering is 1-3 min, and the ignition negative pressure is 3000-6000 Pa; the sintering process is accompanied by ventilation treatment, and the negative pressure of the ventilation is 9000-12000 Pa.

[0013] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0014] This invention uses a certain proportion of high magnesium oxide content iron ore in the sintering process. While ensuring the magnesium oxide content of the sintered ore, it reduces the amount of magnesium-containing flux dolomite used, thereby reducing flux costs. To a certain extent, it can also reduce fuel consumption, thus reducing fuel costs. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0016] The specific process of preparing sintered ore using high-magnesium iron ore powder and its preparation method is as follows:

[0017] Step S1: Prepare the raw materials according to the following mass percentages:

[0018] The raw materials are proportioned as follows by weight percentage: high-magnesium iron ore powder A 0%-20.0%, iron concentrate B 35.0%-50.0%, iron ore powder C 15.0%-35.0%, iron ore powder D 3.0%-20.0%, iron ore powder E 3%-10%, high-silicon flux F 2%-10%, dolomite 0%-6.0%, limestone 0%-5.0%, quicklime 0%-4.0%, coke powder 0.5%-6.0%, and blast furnace return ore 5.0%-15.0%.

[0019] The iron ore powder A, iron concentrate B, iron ore powder C, iron ore powder D, and iron ore powder E are iron materials. The high-magnesium iron ore powder A accounts for 0-20% of the mass of the iron materials, the iron concentrate B accounts for 40-50% of the mass of the iron materials, the iron ore powder C accounts for 15-40% of the mass of the iron materials, the iron ore powder D accounts for 10-25% of the mass of the iron materials, and the iron ore powder E accounts for 5-15% of the mass of the iron materials.

[0020] The high-magnesium iron ore powder A comprises the following components by mass percentage: TFe 56.30–62.50%, FeO 18.50–25.00%, CaO 0.80–1.80%, SiO 23.50–8.50%, MgO 3.00–4.50%, F 0.10–0.40%, P 0–0.10%, and S 0.15–0.80%, with a loss on ignition of 1.15–3.15%.

[0021] Iron concentrate B comprises the following components by mass percentage: TFe 62.5–68.50%, FeO 25.0–29.5%, CaO 0.50–1.50%, SiO2 1.50–3.50%, MgO 0.25–1.20%, F 0.15–0.50%, P 0–0.10%, and S 0.50–1.20%, with a loss on ignition of 1.2–3.00%.

[0022] Iron ore powder C comprises the following components by mass percentage: TFe 58.30–62.50%, FeO 0–1.0%, CaO 0–0.4%, SiO2 3.0–6.0%, MgO 0–0.40%, P 0–0.15%, and S 0.01–0.10%, with a loss on ignition of 2.5–7.5%.

[0023] Iron ore powder D comprises the following components by mass percentage: TFe 58.30–62.50%, FeO 0–1.0%, CaO 0–0.4%, SiO2 3.0–6.0%, MgO 0–0.40%, P 0–0.15%, and S 0.01–0.10%, with a loss on ignition of 2.5–7.5%.

[0024] Iron ore powder E comprises the following components by mass percentage: TFe 56.00–60.50%, FeO 0–1.0%, CaO 0–0.4%, SiO2 3.0–7.0%, MgO 0–0.30%, P 0–0.15%, and S 0.01–0.10%, and the loss on ignition of the iron ore powder D is 5.0–9.5%.

[0025] Step S2: Mix the raw materials with water and then granulate to obtain the mixture.

[0026] Specifically, the raw materials from step S1 are first mixed with water, and after thorough mixing, the resulting mixture is granulated for 2-5 minutes. This granulation process can be carried out in a granulator. Of course, this application is not limited to this and it can also be carried out in other suitable equipment.

[0027] Step S3: Sinter the mixture to obtain sintered ore.

[0028] The moisture content of the mixture is 7%-9% by mass. The ignition time for sintering is 1-3 minutes, and the ignition negative pressure is 8000-12000 Pa. The sintering process is accompanied by ventilation, with a negative pressure of 9000-15000 Pa.

[0029] The sintering process can be carried out on a sintering machine, but this application is not limited to this and other suitable equipment can also be used. The sintering process can be carried out in the following manner:

[0030] The mixture is evenly distributed onto the sintering machine trolley via a distributor, forming a material layer of a certain thickness. It is then ignited by the igniter at the sintering machine head, using coke oven gas as the ignition fuel. The ignition time is 1-3 minutes. Simultaneously, ventilation begins at the bottom of the sintering machine, creating a negative pressure under the grate. The ignition negative pressure is 8000-12000 Pa. After ignition, air is drawn from top to bottom through the sintering material layer. The sintering flue gas is discharged into the atmosphere after a desulfurization process. The sintering ventilation negative pressure is 9000-15000 Pa. The combustion zone on the surface of the material layer gradually moves downwards as the upper fuel burns out. The sintering process ends when the combustion zone reaches the grate, yielding sintered ore.

[0031] The basicity of the sinter of this invention is 1.90-2.10, and the mass percentage of MgO in the sinter is 1.85%-2.25%.

[0032] The method of the present invention will be further described below with reference to specific embodiments.

[0033] The specific components of each raw material used in the following embodiments are shown in Table 1.

[0034] Table 1. Chemical composition (wt%) of the raw materials used.

[0035]

[0036] Example 1

[0037] The raw materials and proportions are prepared according to the specifications shown in Table 2. The raw materials are mixed evenly in a primary mixer, and then granulated in a secondary mixer for 3 minutes. The moisture content of the mixture is controlled at 7.5% by mass. The granulated mixture is then evenly distributed onto the sintering machine trolley via a distributor, with a material layer thickness of 700 mm. Ignition is performed using coke oven gas as the ignition fuel, with an ignition time of 1.5 minutes. Simultaneously, ventilation begins at the bottom of the sintering machine, creating a negative pressure under the grate. The ignition negative pressure is 11000 Pa. After ignition, air is drawn from top to bottom through the sintering material layer. The sintering flue gas is discharged into the atmosphere after desulfurization. The sintering ventilation negative pressure is 13000 Pa. The combustion zone on the surface of the material layer gradually moves downwards as the upper fuel burns out. When the combustion zone reaches the grate, the sintering process ends, yielding sintered ore. The chemical composition and process parameters of this sintered ore are shown in Table 3.

[0038] Example 2

[0039] The raw materials and proportions are prepared according to Table 2. The raw materials are mixed evenly in a primary mixer, and then granulated in a secondary mixer for 4 minutes. The moisture content of the mixture is controlled at 7.8% by mass. The granulated mixture is then evenly distributed onto the sintering machine trolley via a distributor, with a material layer thickness of 700 mm. Ignition is performed using coke oven gas as the ignition fuel, with an ignition time of 2.0 minutes. Simultaneously, ventilation begins at the bottom of the sintering machine, creating a negative pressure under the grate. The ignition negative pressure is 11000 Pa. After ignition, air is drawn from top to bottom through the sintering material layer. The sintering flue gas is discharged into the atmosphere after desulfurization. The sintering ventilation negative pressure is 13000 Pa. The combustion zone on the surface of the material layer gradually moves downwards as the upper fuel burns out. When the combustion zone reaches the grate, the sintering process ends, yielding sintered ore. The chemical composition and process parameters of this sintered ore are shown in Table 3.

[0040] Table 2 Raw material ratios (wt%) for the examples

[0041]

[0042] Table 3 Chemical composition and process parameters of sinter from the examples

[0043]

[0044] As can be seen from Table 3, the chemical composition of the sinter did not change significantly after adding 3.87% and 11.66% of high-magnesium iron ore powder to Examples 1 and 2, respectively. This can meet the requirements of blast furnace for the chemical composition of sinter. The sinter utilization coefficient and the sinter drum strength can also meet the requirements of blast furnace smelting output and quality.

[0045] In summary, this invention uses a certain proportion of high magnesium oxide content iron ore in the sintering process, which reduces the amount of magnesium-containing flux dolomite while ensuring the magnesium oxide content of the sinter. The dolomite ratio is reduced from 5.3% to 4.3%, thereby reducing flux costs and, to some extent, reducing fuel consumption, thus lowering fuel costs.

[0046] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A sintered ore prepared using high magnesia iron ore fines, characterized by: The raw materials are proportioned according to the following mass percentage: high-magnesium iron ore powder A 0%-20.0%, iron ore concentrate B 35.0%-50.0%, iron ore powder C 15.0%-35.0%, iron ore powder D 3.0%-20.0%, iron ore powder E 3%-10%, high-silicon flux F 2%-10%, dolomite 0%-6.0%, limestone 0%-5.0%, quicklime 0%-4.0%, coke powder 0.5%-6.0%, blast furnace return fines 5.0%-15.0%.

2. The sintered ore prepared using high magnesioferrite ore powder according to claim 1, characterized by: The high-magnesium iron ore powder A comprises the following mass percentage of components: TFe 56.30-62.50%, FeO 18.50-25.00%, CaO 0.80-1.80%, SiO2 3.50-8.50%, MgO 3.00-4.50%, F 0.10-0.40%, P 0-0.10%, S 0.15-0.80%, and the burn loss of the iron ore concentrate A is 1.15-3.15%.

3. The sintered ore prepared using high magnesioferrite ore powder according to claim 1, characterized by: The iron ore concentrate B comprises the following mass percentage of components: TFe 62.5-68.50%, FeO 25.0-29.5%, CaO 0.50-1.50%, SiO2 1.50-3.50%, MgO 0.25-1.20%, F 0.15-0.50%, P 0-0.10%, S 0.50-1.20%, and the burn loss of the iron ore concentrate B is 1.2-3.00%.

4. The sintered ore prepared using high magnesioferrite ore powder according to claim 1, characterized by: The iron ore powder C comprises the following mass percentage of components: TFe 58.30-62.50%, FeO 0-1.0%, CaO 0-0.4%, SiO2 3.0-6.0%, MgO 0-0.40%, P 0-0.15%, S 0.01-0.10%, and the burn loss of the iron ore powder C is 2.5-7.5%.

5. The sintered ore prepared using high magnesioferrite ore powder according to claim 1, characterized by: The iron ore powder D comprises the following mass percentage of components: TFe 58.30-62.50%, FeO 0-1.0%, CaO 0-0.4%, SiO2 3.0-6.0%, MgO 0-0.40%, P 0-0.15%, S 0.01-0.10%, and the burn loss of the iron ore powder D is 2.5-7.5%.

6. The sintered ore prepared using high magnesioferrite ore powder according to claim 1, characterized by: The iron ore powder E comprises the following mass percentage of components: TFe 56.00-60.50%, FeO 0-1.0%, CaO 0-0.4%, SiO2 3.0-7.0%, MgO 0-0.30%, P 0-0.15%, S 0.01-0.10%, and the burn loss of the iron ore powder D is 5.0-9.5%.

7. The sintered ore prepared using high magnesioferrite ore powder according to claim 1, characterized by: The sinter has a basicity of 1.90-2.10, and the mass percentage of MgO in the sinter is 1.85%-2.25%.

8. The method of producing sintered ore using high magnesioferrite ore powder according to claim 1, characterized by: The raw materials are mixed with water, granulated to obtain a mixture; the mixture is sintered to obtain a sintered ore; wherein: the granulation time is 2-5 min; the mass percentage of water in the mixture is 7%-9%; the ignition time of sintering is 1-3 min, and the ignition negative pressure is 3000-6000 Pa; the sintering process is accompanied by air draft treatment, and the negative pressure of the air draft is 9000-12000 Pa.

Images