Method for preparing sintered ore from Indian high-silicon fine ore

Abstract

The invention discloses a method for preparing sintered ore from India high-silicon fine ore. The sintered ore is prepared from, by mass, 5%-10% of India high-silicon iron ore powder, 30%-40% of iron ore concentrate A, 35%-45% of iron ore powder B, 10%-15% of iron ore powder C, 3.5%-8.5% of limestone, 0%-4% of light-burned dolomite, 3.0%-4.5% of quick lime and 4.5%-6.0% of coke powder. Adding water into the raw materials, mixing and granulating to obtain a mixture; and distributing, igniting and sintering the mixture to obtain the sintered ore. The invention aims to provide the method for preparing the sintered ore by utilizing the Indian high-silicon fine ore, the Indian high-silicon fine ore is mixed with other iron materials according to a certain proportion, the quality index of the sintered ore can be effectively improved under the condition that the quality index of the sintered ore meets the blast furnace smelting requirement, and meanwhile, the sintering burdening cost can be effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical sintered ore production, and in particular relates to a method for preparing sintered ore by utilizing Indian high-silicon powder ore. Background Art

[0002] Sintered ore is the most important iron-containing charge for blast furnaces. At present, the structure of iron charge for blast furnace is generally high-basicity sintered ore with acidic pellets. In recent years, affected by the fluctuation of steel prices, most steel companies have used a large amount of economic charge in order to reduce the cost of ironmaking, making it difficult to control the sintering process and the quality indicators of sintered ore. For some companies, since their own iron ore resources are magnetically separated iron concentrate, the particle size composition is relatively fine. The permeability of the sintering material layer is seriously deteriorated during the sintering process. In order to improve the permeability of the sintering material layer, a certain proportion of powder ore can be added to the iron material. Most of the iron ores in China are medium-poor ores, and the reserves of rich ores are relatively small. India has large, rich and potential iron ore reserves with a reserve of more than 20 billion tons, of which hematite accounts for 75% of the total reserves. This patent provides an iron ore powder produced in India. The main mineral composition of this ore is limonite, which has a high content of crystal water, a loose structure, a low assimilation temperature, and SiO2. 2 、Al 2 O 3 The content is high, and the content of harmful elements such as phosphorus P, S and heavy metals such as copper, lead, and zinc is low. This Indian high-silicon powder ore can be selected as an auxiliary ore for sintering ore blending, and can form performance complementarity with Baosteel's self-produced concentrate and Australian ore. At the same time, this ore is relatively low in price, and using this ore to prepare sintered ore is conducive to reducing the cost of sintered ore. The present invention provides a solution for producing high-quality and low-cost sintered ore by blending using Indian high-silicon powder ore. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preparing sintered ore by utilizing Indian high-silicon powder ore, so that the sintered ore is mixed with other iron materials in a certain ratio to ensure that the quality index of the sintered ore meets the requirements of blast furnace smelting, thereby effectively improving the quality index of the sintered ore and effectively reducing the sintering ingredient cost.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The invention discloses a method for preparing sintered ore by using Indian high-silicon powder ore. The method comprises the following steps of mixing raw materials in percentage by weight: 5%-10% of Indian high-silicon iron ore powder, 30%-40% of iron concentrate A, 35%-45% of iron ore powder B, 10%-15% of iron ore powder C, 3.5%-8.5% of limestone, 0%-4% of light-burned dolomite, 3.0%-4.5% of quicklime and 4.5%-6.0% of coke powder; adding water to the raw materials, mixing and granulating the raw materials to obtain a mixture; distributing, igniting and sintering the mixture to obtain the sintered ore.

[0006] Furthermore, the Indian high silicon iron ore powder: TFe: 52% to 55%, the main components by mass percentage include: FeO: 1% to 2%, CaO: 0.20% to 1.0%, SiO 2 : 10%~12.5%, MgO: 0.1%~0.16%, Ig: 5.0%~6.0%, K2O<0.20%, S<0.1%.

[0007] Furthermore, the iron concentrate A: TFe: 64.5% to 66.5%, the main components by mass percentage include: FeO: 27.5% to 31.0%, CaO: 0.75% to 2.35%, SiO 2 :1.05%~3.5%, MgO: 0.65%~1.05%, Na 2 O: 0.05% to 0.15%, F: 0.08% to 0.3%, S: 0.65% to 0.95%, K 2 O: 0.05%~0.15%, I g: 1.0%~2.0%, particle size is 200 mesh sieve pass rate 90%~95%.

[0008] Furthermore, the iron ore powder B: TFe: 59.5% to 62.5%, the main components by mass percentage include: FeO: 0.40% to 0.85%, CaO: 0.10% to 0.80%, SiO 2 : 4.0% to 5.5%, MgO: 0.05% to 0.08%, P: 0 to 0.15%, S: 0.025% to 0.120%, Ig: 4.5% to 6.0%.

[0009] Furthermore, the iron ore powder C: TFe: 57.50% to 59.50%, the main components by mass percentage include: FeO: 0 to 0.1%, CaO: 0 to 0.1%, SiO 2 : 4.5% to 5.5%, MgO: 0.05% to 0.08%, P: 0 to 0.10%, S: 0.020% to 0.030%, Ig: 6.5% to 7.8%.

[0010] Furthermore, the basicity of the sintered ore is 2.0-2.05, and the mass percentage of MgO in the sintered ore is 1.90%-2.10%.

[0011] Furthermore, the mass percentage of water in the mixture is 7.0%-9.0%.

[0012] Further, the mixed material is granulated, and the time of the granulation process is controlled to be 4-6 minutes;

[0013] distributing the granulated mixture;

[0014] Ignite the mixed material arranged on the sintering device, wherein the ignition time is controlled to be 1-3 minutes and the ignition negative pressure is 4000-6000Pa;

[0015] The sintering process is accompanied by ventilation, and the negative pressure of the ventilation is 9000-12000Pa.

[0016] Compared with the prior art, the beneficial technical effects of the present invention are:

[0017] The invention uses an Indian high-silicon iron ore powder to mix with other iron materials in a certain ratio through optimizing the ore blending technology. Under the condition of ensuring that the quality index of the sintered ore meets the requirements of blast furnace smelting, the Indian high-silicon iron ore powder can be effectively used to produce sintered ore, and the quality index of the sintered ore can be kept stable. At the same time, the sintering ore blending cost can be effectively reduced by adding the Indian high-silicon iron ore powder.

[0018] 1) Using Indian high-silicon iron ore powder to produce sintered ore can reduce the cost of sintered ore raw materials. Based on the annual demand of 240,000 tons of benchmark ore, this ore is 238 yuan / ton lower than the benchmark ore, which can reduce the cost of sintered raw materials by 57.266 million yuan / year. At the same time, using this Indian high-silicon iron ore powder to replace imported mainstream ore can reduce the proportion of serpentine in silicon flux by 1%, which can reduce the annual consumption of serpentine by 5,000 tons and reduce the cost of sintering flux by 5 million yuan / year.

[0019] 2) The use of this Indian high-silicon iron ore powder to produce sintered ore has reduced the drum index of sintered ore by 0.02%, increased the hourly output and utilization factor by 1.6t / h and 0.006t / (m2.h) respectively, and reduced the average solid fuel consumption by 0.49kg / t compared with the baseline period. It can achieve high-efficiency and low-consumption sintering production, with considerable economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings.

[0021] Figure 1 The present invention is a flow chart of a method for preparing sintered ore using Indian high-silicon powder ore. DETAILED DESCRIPTION

[0022] The following is combined with Figure 1 The specific embodiments of the present invention are described as follows:

[0023] In this embodiment, four kinds of iron ore raw materials are used at 265m 2 Trial production was carried out on the sintering machine, and the four raw materials were:

[0024] Furthermore, the Indian high-silicon iron ore powder: TFe: 52% to 55%, the main components in terms of mass percentage include: FeO: 1% to 2%, CaO: 0.20% to 1.0%, SiO2: 10% to 12.5%, MgO: 0.1% to 0.16%, Ig: 5.0% to 6.0%, K2O<0.20%, S<0.1%.

[0025] Furthermore, the iron concentrate A: TFe: 64.5% to 66.5%, the main components by mass percentage include: FeO: 27.5% to 31.0%, CaO: 0.75% to 2.35%, SiO 2 :1.05%~3.5%, MgO: 0.65%~1.05%, Na 2 O: 0.05% to 0.15%, F: 0.08% to 0.3%, S: 0.65% to 0.95%, K 2 O: 0.05%~0.15%, I g: 1.0%~2.0%, particle size is 200 mesh sieve pass rate 90%~95%.

[0026] Furthermore, the iron ore powder B: TFe: 59.5% to 62.5%, the main components by mass percentage include: FeO: 0.40% to 0.85%, CaO: 0.10% to 0.80%, SiO 2 : 4.0% to 5.5%, MgO: 0.05% to 0.08%, P: 0 to 0.15%, S: 0.025% to 0.120%, Ig: 4.5% to 6.0%.

[0027] Furthermore, the iron ore powder C: TFe: 57.50% to 59.50%, the main components by mass percentage include: FeO: 0 to 0.1%, CaO: 0 to 0.1%, SiO 2 : 4.5% to 5.5%, MgO: 0.05% to 0.08%, P: 0 to 0.10%, S: 0.020% to 0.030%, Ig: 6.5% to 7.8%.

[0028] The raw materials are mixed according to the raw materials shown in Table 1 and the proportions shown in Table 2. The raw materials are mixed with water in the primary mixer, and the moisture content is controlled to 7.0%; then the raw materials are granulated in the secondary mixer, and the granulation time is 3 minutes; the granulated mixture is evenly distributed to the sintering device through the distributor, and the material layer thickness is 780mm, and ignited by the sintering igniter. The ignition fuel is natural gas, and the ignition time is 2.0 minutes. At the same time, the bottom of the sintering device begins to evacuate, and a certain negative pressure is formed under the grate. The ignition negative pressure is 5000Pa. After ignition, the air is evacuated from top to bottom through the sintering material layer. The sintering evacuation negative pressure is 10000Pa. After ignition, the burning zone on the surface of the material layer gradually moves to the lower material layer as the upper fuel is burned. When the burning zone reaches the grate, the sintering process ends and sintered ore is obtained.

[0029] Example:

[0030] Under different proportions of Indian high silicon iron ore powder in the sintered iron material (as shown in Table 2), the chemical composition of the sintered ore and the sintering process indicators were compared and analyzed (as shown in Table 3 and Table 4).

[0031] Table 1 Chemical composition of raw materials for sintering (wt%)

[0032]

[0033] Table 2 Raw material ratio (wt%) of the embodiment

[0034]

[0035] The chemical composition of the sintered ore and the economic and technical indicators of the sintering process parameters are shown in Tables 3 and 4.

[0036] Table 3 Chemical composition of the sintered ore of the embodiment (mass fraction, %)

[0037]

[0038] Table 4 Process parameters and economic and technical indicators of the embodiment

[0039]

[0040] It can be seen from Table 3 and Table 4 that:

[0041] Output level: Compared with the benchmark case, with the increase of the proportion of Indian high-silicon iron ore powder, the hourly output and utilization factor continued to increase, and the cold return unit consumption decreased slightly. Solid fuel consumption: Compared with the benchmark case, with the increase of the proportion of Indian high-silicon iron ore powder, the solid fuel consumption showed an increasing trend. The average solid fuel consumption of the example increased by 0.10kg / t compared with the benchmark period. Drum strength: With the increase of the proportion of Indian high-silicon iron ore powder, the drum strength showed a decreasing trend. The drum strength of the example period decreased by 0.04-0.08% compared with the benchmark period. The main reason is that during the test period, after the use of Indian ore to replace Brazilian coarse powder, the proportion of limonite in the sintering mixture increased, the fuel consumption was high, and it was not conducive to the formation of calcium ferrite.

[0042] The economic benefit calculation of adding Indian high silicon iron ore powder to sintering shows that the price of Indian high silicon iron ore powder used during the implementation period is 630 yuan / ton, and the price of replacing Brazilian coarse powder is 869 yuan / ton. The price of Indian high silicon iron ore powder is 150.46 yuan / ton lower than that of the alternative ore of the same grade. Based on the calculation of using 20,000 tons of this ore per month, the sintering raw material cost can be reduced by 3 million yuan / month.

[0043] The example shows that the production of sintered ore using Indian high-silicon powder ore has considerable economic and social benefits.

[0044] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing sintered ore using Indian high-silicon powder ore, characterized in that: The raw materials are prepared according to the following percentage by mass: 5%-10% of Indian high silicon iron ore powder, 30%-40% of iron concentrate A, 35%-45% of iron ore powder B, 10%-15% of iron ore powder C, 3.5%-8.5% of limestone, 0%-4% of lightly burned dolomite, 3.0%-4.5% of quicklime, and 4.5%-6.0% of coke powder; the raw materials are added with water, mixed and granulated to obtain a mixture; the mixture is distributed, ignited, and sintered to obtain a sintered ore.

2. The method for preparing sintered ore using Indian high-silicon powder ore according to claim 1, characterized in that: The Indian high silicon iron ore powder: TFe: 52% to 55%, the main components according to mass percentage include: FeO: 1% to 2%, CaO: 0.20% to 1.0%, SiO2: 10% to 12.5%, MgO: 0.1% to 0.16%, Ig: 5.0% to 6.0%, K2O<0.20%, S<0.1%.

3. The method for preparing sintered ore using Indian high-silicon powder ore according to claim 1, characterized in that: The iron concentrate A: TFe: 64.5% to 66.5%, the main components include by mass percentage: FeO: 27.5% to 31.0%, CaO: 0.75% to 2.35%, SiO2: 1.05% to 3.5%, MgO: 0.65% to 1.05%, Na2O: 0.05% to 0.15%, F: 0.08% to 0.3%, S: 0.65% to 0.95%, K2O: 0.05% to 0.15%, Ig: 1.0% to 2.0%, the particle size is 200 mesh sieve passing rate 90% to 95%.

4. The method for preparing sintered ore using Indian high-silicon powder ore according to claim 1, characterized in that: The iron ore powder B: TFe: 59.5% to 62.5%, the main components include by mass percentage: FeO: 0.40% to 0.85%, CaO: 0.10% to 0.80%, SiO2: 4.0% to 5.5%, MgO: 0.05% to 0.08%, P: 0 to 0.15%, S: 0.025% to 0.120%, Ig: 4.5% to 6.0%.

5. The method for preparing sintered ore using Indian high-silicon powder ore according to claim 1, characterized in that: The iron ore powder C: TFe: 57.50% to 59.50%, the main components according to mass percentage include: FeO: 0 to 0.1%, CaO: 0 to 0.1%, SiO2: 4.5% to 5.5%, MgO: 0.05% to 0.08%, P: 0 to 0.10%, S: 0.020% to 0.030%, Ig: 6.5% to 7.8%.

6. The method for preparing sintered ore using Indian high-silicon powder ore according to claim 1, characterized in that: The basicity of the sintered ore is 2.0-2.05, and the mass percentage of MgO in the sintered ore is 1.90%-2.10%.

7. The method for preparing sintered ore using Indian high-silicon powder ore according to claim 1, characterized in that: The mass percentage of water in the mixture is 7.0%-9.0%.

8. The method for preparing sintered ore using Indian high-silicon powder ore according to claim 1, characterized in that: The mixed material is granulated, and the time of the granulation process is controlled to be 4-6 minutes; distributing the granulated mixture; Ignite the mixed material arranged on the sintering device, wherein the ignition time is controlled to be 1-3 minutes and the ignition negative pressure is 4000-6000Pa; Furthermore: the sintering process is accompanied by ventilation treatment, and the negative pressure of the ventilation is 9000-12000Pa.

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